Interfacing and Commissioning of Motor and Drive to the Tandem test jig
Final BE report
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1. Introduction
In today’s fast moving world, where the aim for automobiles is to move as fast as
possible, with maximum fuel economy and the cars be as light as possible, the possible
change in engine materials and body material have acquired core importance. As a direct
consequence, it has become mandatory to test the effects of various coolants on new
prospective engine materials and verify the corrosion resistance of these materials when
subjected to the high pressure and temperatures of the engine block.
In association with the Automotive Research Association of India (ARAI) a rig in
accordance with the Indian and Japanese standards to satisfy the above rigorous demands
has been built. The rig at the same time has been built with the highest safety standards
and it requires minimum human intervention for its working. It also includes all the
modern appurtenances like touch screen, GSM technology that make it a robust, attractive
as well as a technologically adept construction. The old rig although built according to the
Japanese and Indian standards, lacked the safety features and the appearances of a modern
compact rig. The main aim of this rig is to test the corrosive effects of coolants on various
engine materials. The old construction also lacked automation and would require human
intervention on an hourly basis to note the readings. The surface area also was very large.
This setup has also faced problems of leakage and time required to reach the steady state
condition.
Nonetheless the old rig for all its drawbacks, served as a very useful guide to build
the new rig. The old rig also provided accurate results for ARAI to sanction a new
modern rig build on the same technical standards albeit with better features. One of the
main objectives of the new setup has been to overcome these drawbacks and build a rig
that is compact and most importantly a setup that is safe to operate. It was imperative to
make the new setup friendly to use and to achieve this goal; a touch screen setup has been
integrated in the new rig. Along with this an auto shut down feature and timely alarms
have been included to make the setup as safe as possible. The use of PLC technology has
insured that readings will be taken on an hourly basis and saved as data thus eliminating
the need for the working people to note down the readings. The use of GSM technology
has made remote shutting down of the rig possible. The technology has also been used to
get important alerts and updates regarding the functioning of the rig. The other
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improvements suggested included use of timing belt rather than simple belt. This would
help in achieving a better and noiseless power transmission from the motor to the water
pump. The heater rather than the pan type in the old rig, a band type heater in the new rig
has been suggested. The use of this heater will reduce the time require to reach the steady
state condition and also prove to be aesthetically more appealing than the plate heater
previously used. The new rig also is base on three phase supply which will aid safety and
avoid downtime in case of shortage of electricity. The piping in the new rig is of a
superior quality. Fewer bends and elbows and overall reduction in length will reduce heat
losses and is also beneficial from an economic point of view. The new setup will be
enclosed from all sides and give it the appearance of a closed box with doors at the front.
This will contribute to the safety and aesthetics, giving it a compact look .The technical,
aesthetic and safety improvements in the new rig will considerably help to overcome the
drawbacks of the crude setup.
Figure 1.1 the Old Setup
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2. Literature Survey
2.1Centrifugal Pump
A pump always works on the principle of conversion of mechanical energy into
equal pressure energy. A pump coupled to a motor hence acts as a power absorbing
device. The JIS and IS standards prescribed use of a centrifugal pumps and hence only
these kinds of pumps were surveyed.
Figure 2.1 Centrifugal Pump
2.1.1 Working of the pump
Centrifugal pumps, (fig 2.1) are a sub-class of dynamic axi-symmetric work-
absorbing machinery. The purpose of a centrifugal pump is to convert energy of a prime
mover (a electric motor or turbine) first into velocity or kinetic energy and then into
pressure energy of a fluid that is being pumped. The energy changes occur by virtue of
two main parts of the pump, the impeller and the volute or diffuser. The impeller is the
rotating part that converts driver energy into the kinetic energy. The volute or diffuser is
the stationary part that converts the kinetic energy into pressure energy. The process
liquid enters the suction nozzle and then into eye (centre) of a revolving device known as
an impeller. When the impeller rotates, it spins the liquid sitting in the cavities between
the vanes outward and provides centrifugal acceleration. As liquid leaves the eye of the
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impeller a low-pressure area is created causing more liquid to flow toward the inlet.
Because the impeller blades are curved, the fluid is pushed in a tangential and radial
direction by the centrifugal force. This force acting inside the pump is the same one that
keeps water inside a bucket that is rotating at the end of a string. The key idea is that the
energy created by the centrifugal force is kinetic energy.
The amount of energy given to the liquid is proportional to the velocity at the edge
or vane tip of the impeller. The faster the impeller revolves or the bigger the impeller is,
then the higher will be the velocity of the liquid at the vane tip and the greater the energy
imparted to the liquid. This kinetic energy of a liquid coming out of an impeller is
harnessed by creating a resistance to the flow.
The first resistance is created by the pump volute (casing) that catches the liquid
and slows it down. In the discharge nozzle, the liquid further decelerates and its velocity
is converted to pressure according to Bernoulli’s principle. Therefore, the head (pressure
in terms of height of liquid) developed is approximately equal to the velocity energy at
the periphery of the impeller. The standards prescribe to have a discharge of 60lpm with a
tolerance of 10 LPM. These parameters shall dictate the speed of the pump based on the
operating characteristics. For any pump the discharge is directly proportional to the speed
of the pump. The centrifugal pump should hence run at a reasonable speed and create the
required discharge to satisfy the standards.
2.2 Motor
A motor is a power producing device that absorbs electrical energy and produces
equal amount of mechanical energy. The motor is coupled to the pump via a timing belt
drive. An electric motor can operate on both alternating current (AC) and direct current
(DC).Although the principle remains the same, there is a striking difference in the
characteristics of these motors.
Motors are generally foot mounted with squirrel cage construction. This provides
for a robust construction. Flange mounted motors are also available but generally foot
mounted are preferred.
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Figure 2.2 Classification of Motors
2.2.1Working of DC motor
The working principle behind any DC motor is the attraction and repulsion of
magnets. The simplest motors use electromagnets on a shaft, with permanent magnets in
the case of the motor that attract and repel the electromagnets.
Figure 2.3 Working of a brush DC motor
The reason for using electromagnets is so that it is possible to flip their magnetic
field (their north and south poles). So the electromagnet is attracted to one of the
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permanent magnets. As soon as it reaches the permanent magnet, its north and south poles
flip so that it is repelled from that magnet and attracted to the other permanent magnet. A
DC motor can be of brush or brushless type.
The Advantages of a DC motor are
1) DC drives are less complex with a single power conversion from AC to DC.
2) DC drives are normally less expensive for most horsepower ratings.
3) DC motors have a long tradition of use as adjustable speed machines and a wide
range of options have evolved for this purpose
4) DC drives are less complex with a single power conversion from AC to DC.
5) DC drives are normally less expensive for most horsepower ratings.
6) DC motors have a long tradition of use as adjustable speed machines and a wide
range of options have evolved for this purpose
7) Cooling blowers and inlet air flanges provide cooling air for a wide speed range at
constant torque.
8) Accessory mounting flanges and kits for mounting feedback tachometers and
encoders.
9) DC regenerative drives are available for applications requiring continuous
regeneration for overhauling loads. AC drives with this capability would be more
complex and expensive.
10) DC motors are capable of providing starting and accelerating torques in excess of
400% of rated.
11) Some AC drives may produce audible motor noise which is undesirable in some
applications.
2.2.2 Working of AC Motor
The principle of an AC motor is Faraday’s law of induction that states” the rate of
change of magnetic flux is directly proportional to the current passing through the
coil.”AC motor is an electric driven by an alternating current (AC).It commonly consists
of two basic parts, an outside stationary stator having coils supplied with alternating
current to produce a rotating magnetic field, and an inside rotor attached to the output
shaft that is given a torque by the rotating field. There are two main types of AC motors,
depending on the type of rotor used. The first type is the induction motor, which runs
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slightly slower than the supply frequency. The magnetic field on the rotor of this motor is
created by an induced current. The second type is the synchronous motor, which does not
rely on induction and as a result, can rotate exactly at the supply frequency or a sub-
multiple of the supply frequency. The magnetic field on the rotor is either generated by
current delivered through slip rings or by a permanent magnet. Other types of motors
include eddy current motors, and also AC/DC mechanically commutated machines in
which speed is dependent on voltage and winding connection. The most commonly used
AC motor is always the 3 phase induction motor.
Figure 2.4 Working of AC motor
2.2.3 Working of 3 Phase Induction Motor
The stator of an induction motor consists of a number of overlapping windings
offset by an electrical angle of 120°. When the primary winding or stator is connected to a
three phase alternating current supply, it establishes a rotating magnetic field which
rotates at a synchronous speed. The direction of rotation of the motor depends on the
phase sequence of supply lines, and the order in which these lines are connected to the
stator. Thus interchanging the connection of any two primary terminals to the supply will
reverse the direction of rotation. The number of poles and the frequency of the applied
voltage determine the synchronous speed of rotation in the motor’s stator. Motors are
commonly configured to have 2, 4, 6 or 8 poles. The synchronous speed, a term given to
the speed at which the field produced by primary currents will rotate, is determined by the
following expression.
Synchronous speed of rotation = (120* supply frequency) / Number of poles on the stator.
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Figure 2.5 Foot mounted AC induction motor
A rotating magnetic field in the stator is the first part of operation. To produce a
torque and thus rotate, the rotors must be carrying some current. In induction motors, this
current comes from the rotor conductors. The revolving magnetic field produced in the
stator cuts across the conductive bars of the rotor and induces an e.m.f. The rotor
windings in an induction motor are either closed through an external resistance or directly
shorted. Therefore, the e.m.f induced in the rotor causes current to flow in a direction
opposite to that of the revolving magnetic field in the stator, and leads to a twisting
motion or torque in the rotor. As a consequence, the rotor speed will not reach the
synchronous speed of the r.m.f in the stator. If the speeds match, there would be no e.m.f.
induced in the rotor, no current would be flowing, and therefore no torque would be
generated. The difference between the stator (synchronous speed) and rotor speeds is
called the slip. The rotation of the magnetic field in an induction motor has the advantage
that no electrical connections need to be made to the rotor.
The Advantages of these motors are
1) They use conventional, low cost, 3-phase AC induction motors for
most applications.
2) AC motors require virtually no maintenance and are preferred for
applications where the motor is mounted in an area not easily reached for
servicing or replacement.
3) AC motors are smaller, lighter, more commonly available, and less expensive than
DC motors.
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4) AC motors are better suited for high speed operation (over 1500 rpm) since there
are no brushes, and commutation is not a problem.
5) Whenever the operating environment is wet, corrosive or explosive and special
motor enclosures are required. Special AC motor enclosure types are more readily
available at lower prices.
6) Multiple motors in a system must operate simultaneously at a common
frequency/speed.
7) It is desirable to use an existing constant speed AC motor already mounted and
wired on a machine.
8) When the application load varies greatly and light loads may be encountered for
prolonged periods. DC motor commutators and brushes may wear rapidly under
this condition.
9) Low cost electronic motor reversing is required.
10) It is important to have a back up (constant speed) if the controller should fail.
2.3 Heater
A heater as the name suggests is a device used to heat the working fluid to the
desired temperature. For any heater, the most important design parameter is its wattage. A
heater must be able to heat the required fluid to its required temperature. It should also be
safe to use and be long lasting with very good repeatability.
Figure 2.6 Various types of heaters
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The various types of industrial heaters include Tubular Heaters, Coil Nozzle Heaters,
Cartridge Heaters, Blower Heaters, and Band Heaters. Casting Heaters, Strip Heaters,
Ceramic Infrared Heaters, Porcelain Jacket Heaters, Quartz Infrared Heaters and Sealed
Nozzle Heaters. The main heaters analyzed were pan type heaters and band type heaters.
Coil type of heaters are not considered because they have a tendency to short easily while
immersion type heaters are not considered because their use would involve drilling holes
in the tank and thus increasing the possibility of leakages.
2.3.1 Pan Type Heaters
Pan type heaters are indirect contact type heaters used in industries. These are the
simplest types of heaters that are available. The heater is generally placed at the bottom of
the tank containing fluid and heating of the fluid shall take place.
Figure 2.7 Pan Type heaters
The Advantages of Pan type heaters are
1) Cheaper compared to band heaters
2) Simple Construction
3) High temperatures can be achieved
The limitations of Pan Type heaters are
1) Construction though simple, it is very large in size
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2) A large amount of heat is lost to surroundings
3) Not as energy efficient compared to Band heaters
4) The design is not as aesthetically appealing as a band heater.
2.3.2 Band Type Heaters
Band heaters are an improvement of the conventional coil heaters. Band heaters
are generally made of Mica or Ceramic. These heaters are more energy efficient
compared to their coil and pan type counterparts. These are attached on the outer
periphery of the cylinder bath a hence do not require additional support like pan type
heaters which are kept at the bottom of the cylinder bath.
Figure 2.8 A regular Band Heater
2.3.3 Construction details and Characteristics of Band Heaters
Figure 2.9 Construction details of band heater
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Chrome Nickel Steel Sheathing-Chrome Nickel Steel housing with serrated edges
provides maximum flexibility for ease of installation.
Thermal Insulation- Built-In heat saving Thermal Insulation standard (4mm) on
all Ceramic Bands and Mica Band will reduce power consumption to almost 80% of
conventional coil heaters of same wattage. Further reduction can be obtained with higher
thickness insulation which prevents heat loss, thereby lowering energy costs.
High Grade Ceramic/Mica Insulators-Interlocking Steatite bricks designed for best
combination of physical & dielectric strength, good thermal conductivity to heat
cylindrical parts, good for sheath temperature up to 650°C also provides flexibility for
ease of installation on the barrel.
Ni-Chrome heating coil-Nickel-Chrome resistance wire designed for maximum
current carrying capacity is strung through specially designed ceramic insulating bricks
providing even heat distribution, thus eliminating hot spotting that can cause premature
heater failure.
Advantages of Band type heaters
1) High temperature range up to 650 degrees.
2) Better energy efficiency.
3) Wide range of applications.
4) Aesthetically appealing.
5) Easy removal and installations.
6) Available in various clampings and lead terminations.
Typical Applications
1) Plastic Injection Moulding Machines.
2) Plastic Extruders.
3) Oil Reclamation Equipment.
4) Food and Candy Extruders.
5) Drum Heating.
6) Extrusion Dies.
7) Holding Tanks.
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2.4 Engine Material Strips
Although the aim of the project is to construct a coolant corrosion test rig, the
larger picture involves testing the effects of various coolants on various engine materials.
These strips are extremely important as they will replicate the performance of the various
engine materials when the automobile is running.
The fundamental principle of operation is a combustion process occurring near the
point of greatest compression of the air and fuel mixture by the piston in the cylinder (top
dead centre). The expanding gases then force the piston to the point of greatest defined
cylinder volume (bottom dead centre), resulting in a power stroke, whereby the force of
combustion does work on the crankshaft through the connecting rod which attaches the
piston to the crankshaft.
Figure 2.10 Basic components of the IC engine
The expanded gases are exhausted when the piston, on its continuing stroke, forces them
out of the cylinder, typically through an arrangement of valves. The principal materials
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systems in the powercylinder portion of the engine are the cylinder block, engine head,
connecting rod, piston, crankshaft, and valverain.
Naturally, an operating engine will incorporate hundreds of ancillary parts
including manifolds, fuel handling system, bearings, fasteners, timing chains or belts, and
flywheel, etc However, the above items fundamentally dictate the manufacturing protocol
for the engine. Depending on its design, the valve train may incorporate differing
materials technologies employed to achieve such objectives as reduced weight, extreme
durability, or high strength.
The pre-eminent material of cylinder block and head construction since the
inception of the internal combustion engine has been gray cast iron. Gray cast iron is
produced to its near final shapely sand casting, permitting incorporation of appropriate
coolant channels, attachment bosses, and air/fuel passageways of the cylinder head,
through use of sand cores. Gray iron provides a durable, machinable, and recyclable
material for the block and head application with a nearly ideal running surface for the
piston and ring pack of the power cylinder .Concerns regarding engine weight have led
over the years to an increasing use of aluminium for automotive cylinder blocks and
heads, such that current worldwide usage of aluminium in this application approaches
50% of all blocks and cylinders. More recently, aluminium is finding use in diesel
applications where weight reduction is the primary consideration .Compacted graphite
iron is an emerging cylinder block material having a higher specific strength than
conventional gray iron, and with improved fatigue strength and acoustic properties
relative to aluminium, thereby allowing cast iron blocks of reduced thickness and mass to
be constructed.
The crankshaft, supported by the journal bearings and crankcase in in-line and V-
configurations, transmits the force of combustion, via the pistons and connecting rods,
through the transmission to the driveline, or in hybrid configurations to an electrical
generator. For engines under significant loads, the traditional crankshaft material is
forged, alloyed steel, including micro alloyed grades containing small additions of
vanadium, titanium, or niobium, which permit development of superior surface strength,
resistance to fatigue, and surface durability in the bearing contacts.
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In recent years, smaller lower-power internal combustion engines have exploited
the use of nodular cast iron, having both economic implications for manufacture and
excellent vibration damping capability. The connecting rod provides the mechanical
linkage between piston and crankshaft and must exhibit properties of high strength, low
inertial mass, and uniformity of mass with the other connecting rods attached to the
crankshaft.
The connecting rod large ends are often threaded directly such that the split
portion may be attached during assembly with the crankshaft. Materials for connecting
rods have included powder metallurgy steels, which are formed into an initial shape then
forged to near final dimension, as well as medium carbon steels, which develop superior
strength either through separate heat treating processes or by controlled cooling following
the forging step. Racing engines may utilize titanium alloys such as Ti-6A14V for
connecting rods in order to achieve a high ratio of strength to mass of the part.
Automotive engine pistons are most frequently made from aluminium alloys,
usually with high silicon content to improve stiffness while reducing overall density, and
may be cast or forged. Many diesel and high power density engines require pistons of
alloy cast iron such as nickel-containing grades, due to the high temperatures encountered
in the combustion chamber.
Pistons may have unique engineered shapes to the combustion facing surface, as
well as surface treatments to resist wear and ring sticking in the ring grooves, and
mitigation of thermal effects on the piston crown. Friction-reducing coatings, including
graphite or molybdenum disulfide, are applied on the piston skirt surfaces which may
contact the cylinder walls under certain operating conditions.
In four-cycle SI and CI engines, the valve train provides for the mechanical action
which synchronizes the flows of air, fuel, and exhausts with the intake, compression,
power, and exhaust strokes of the piston in cylinder.). These systems consist
fundamentally of the engine valves, camshaft, and intervening mechanisms that typically
include tappets; combustion engines may employ camless systems to permit control of
valve operation without mechanical linkage to components such as the crankshaft.
Valves may be made of plain carbon alloy steels in the case of intake valves,
however, higher hot-strength, corrosion, and wear resistance are required for exhaust
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valves. Materials of choice are heat-treatable Fe-Cr-Si (Silchrome) alloys or austenitic
stainless steels (e.g., designation 21-4N). Performance engines may employ high strength
materials such as titanium alloys or even ceramic valves fabricated of silicon nitride,
these latter approaches being utilized to achieve weight and friction reduction of the valve
train. Valves for extreme durability conditions may be constructed of nickel-based super
alloys such as Nimonic or Inconel grades. For severe operating conditions such as found
in diesel and gaseous-fuel engines, a facing may be required for the valve seating surface.
This is often accomplished with cobalt- or nickel-based hard facing alloys.
.
Figure 2.11 the Test Specimens
2.5 Coolants
A coolant is a fluid which flows through or around a device to prevent it’s
overheating, transferring the heat produced by the device to other devices that use or
dissipate it. An ideal coolant has high thermal capacity, low viscosity, is low-cost, non-
toxic, and chemically inert, neither causing nor promoting corrosion of the cooling
system. Some applications also require the coolant to be an electrical insulator. While the
term coolant is commonly used in automotive applications, in industrial processing, heat
transfer fluid is one technical term more often used, in high temperature as well as low
temperature manufacturing applications.
The most common coolant is water. Its high heat capacity and low cost makes it a
suitable heat-transfer medium. It is usually used with additives, like corrosion inhibitors
and antifreeze. Antifreeze, a solution of a suitable organic chemical (most often ethylene
glycol, diethylene glycol, or propylene glycol) in water, is used when the water-based
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coolant has to withstand temperatures below 0 °C, or when its boiling point has to be
raised. Betaine is a similar coolant, with the exception that it is made from pure plant
juice, and is therefore not toxic or difficult to dispose of ecologically.
Very pure deionised water, due to its relatively low electrical conductivity, is used
to cool some electrical equipment, often high-power transmitters and high-power vacuum
tubes. Heavy water is a neutron moderator used in some nuclear reactors; it also has a
secondary function as their coolant.
Light water reactors, both boiling water and pressurized water reactors the most
common type, use ordinary (light) water. Polyalkylene glycol (PAG) is used as high
temperature, thermally stable heat transfer fluids exhibiting strong resistance to oxidation.
Modern PAG's can also be non-toxic and non-hazardous.
Conventional fluids, such as refrigerants, water, engine oil, ethylene glycol, etc.
have poor heat transfer performance and therefore high compactness and effectiveness of
heat transfer systems are necessary to achieve the required heat transfer. Among the
efforts for enhancement of heat transfer the application of additives to liquids is more
noticeable. Recent advances in nanotechnology have allowed development of a new
category of fluids termed nanofluids. Such fluids are liquid suspensions containing
particles that are significantly smaller than 100 nm, and have a bulk solids thermal
conductivity higher than the base liquids. Nanofluids are formed by suspending metallic
or non-metallicoxide nanoparticles in traditional heat transfer fluids. These so called
nanofluids display good thermal properties compared with fluids conventionally used for
heat transfer and fluids containing particles on the micrometer scale. Nanofluids are the
new window which was opened recently and it was confirmed by several authors that
these working fluid can enhance heat transfer.[3]
2.5.1 Ethylene Glycol
Pure ethylene glycol has a specific heat capacity about one half that of water. So,
while providing freeze protection and an increased boiling point, ethylene glycol lowers
the specific heat capacity of water mixtures relative to pure water.
A 50/50 mix by mass has a specific heat capacity of about 0.75 BTU/lb F, thus
requiring increased flow rates in same system comparisons with water. Additionally, the
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increase in boiling point over pure water inhibits nucleate boiling on heat transfer
surfaces thus reducing heat transfer efficiency in some cases, such as gasoline engine
cylinder walls. Therefore, pure ethylene glycol should not be used as an engine coolant in
most cases.
Properties of Ethylene Glycol
Table 2.1 Properties of Ethylene Glycol
Molecular formula C2H6O2
Molar mass 62.07 g mol−1
Density 1054kg/m³
Melting point −12.9 °C, 260 K, 9 °F
Boiling point 197.3 °C, 470 K, 387 °F
Solubility in water Miscible with water
in all proportions.
Viscosity 0.278x10-2
N*s / m2
Ethylene glycol freezing point vs. concentration in water
Weight Percent EG
(%)
Freezing Point
(°F)
Freezing Point
(°C)
0 32 0
10 25 -4
20 20 -7
30 5 -15
40 -10 -23
50 -30 -34
60 -55 -48
70 -60 -51
80 -50 -45
90 -20 -29
100 10 -12
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An alternative antifreeze base is propylene glycol. There is very little difference in
the performance of either substance; the advantage is the toxicity level. Propylene glycol
is significantly less toxic than ethylene glycol. Propylene glycol is a component in newer
automotive antifreezes and de-icers used at airports. Like ethylene glycol, the freezing
point of water is depressed when mixed with propylene glycol owing to the effects of
dissolution of a solute in a solvent (freezing-point depression); glycols are good for this
purpose as they are cheap, non-corrosive and have very low volatility[4].
2.6 Radiator
Radiators are used for cooling internal combustion engines, mainly in automobiles
but also in piston-engine aircraft, railway locomotives, motorcycles, stationary generating
plant or any similar use of such an engine. Internal by passing a liquid called engine
coolant through the engine block, where it is heated, then through the radiator itself where
it loses heat to the atmosphere, and then back to the engine in a closed loop. Engine
coolant is usually water-based, but may also be oil. It is common to employ a water pump
to force the engine coolant to circulate, and also for an axial fan to force air through the
radiator.
In automobiles with a liquid-cooled internal combustion engine, a radiator is
connected to channels running through the engine and cylinder head, through which a
coolant is pumped. This liquid may be water in climates where water is unlikely to freeze,
but is more commonly a mixture of water and antifreeze in proportions appropriate to the
climate. Antifreeze itself is usually ethylene glycol or glycol, with a small amount of
inhibitor. The radiator transfers the heat from the fluid inside to the air outside, thereby
cooling the fluid, which in turn cools the engine. Radiators are also often used to cool
automatic transmission fluids, conditioner refrigerant, intake air, and sometimes to cool
motor oil or power steering fluid. Radiators are typically mounted in a position where
they receive airflow from the forward movement of the vehicle, such as behind a front
grill. Where engines are mid- or rear-mounted, it is common to mount the radiator behind
a front grill to achieve sufficient airflow, even though this requires long coolant pipes.
Alternatively, the radiator may draw air from the flow over the top of the vehicle or from
a side-mounted grill. For long vehicles, such as buses, side airflow is most common for
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engine and transmission cooling and top airflow most common for air conditioner
cooling.
Automobile radiators are constructed of a pair of header tanks, linked by a core
with many narrow passageways, thus a high surface area relative to its volume. This core
is usually made of stacked layers of metal sheet, pressed to form channels and soldered or
brazed together. For many years radiators were made from brass or copper cores soldered
to brass headers. Modern radiators save money and weight by using plastic headers and
may use aluminium cores. This construction is less easily repaired than traditional
materials. Radiators first used downward vertical flow, driven solely by a thermo-siphon
effect. This system is called the Thermo-Siphon system. Coolant is heated in the engine,
becomes less dense, and so rises. As the radiator cools the fluid, the coolant becomes
denser and falls. This effect is sufficient for low-power stationary engines, but inadequate
for all but the earliest automobiles. As a result all automobiles for many years have used
centrifugal pumps to circulate the engine coolant because natural circulation has very low
flow rates. This is called the pump circulation system. In this system the water pump is
driven by the engine power by means of a timing belt connected from the engine
crankshaft.
This system has following advantages over the thermo-siphon system
1) Circulation of coolant is both proportional to load and speed
2) Unlike the thermo siphon system it is not mandatory to place the coolant tank over
the radiator. As a result the system is more compact.
There are two main types of radiator cores viz. tubular type and cellular type. In
the former the coolant flows through tubes and air passes around them while in the
cellular type air passes through the tubes and coolant flows in between them .Out of these
tubular types cores are more commonly used and further classified depending on the
shape of the fins around the tubes that are meant to increase the area of heat transfer from
coolant to the cooling air. The core tubes and the fins are made from the thinnest possible
material. The tubes are made from 0.1mm to 0.3mm sheets while fins are made from
about 0.1mm thick material[4].
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2.7 Fabrication Materials
2.7.1Type 304 Stainless Steel
Type 304, with its chromium-nickel content and low carbon, is the most versatile
and widely used of the austenitic stainless steels. Type 304 alloys are all modifications of
the 18% chromium, 8% nickel austenitic alloy. Applications for this group of alloys are
varied and all possess somewhat similar characteristics in resistance to oxidation,
corrosion, and durability. All provide ease of fabrication and cleaning, prevention of
product contamination and over a variety of finishes and appearances.
2.7.2 General Properties of Type 304 Stainless Steel
Type 304 stainless steels can meet a wide variety of physical requirements,
making them excellent materials for applications including auto moulding and trim, wheel
covers, kitchen equipment, hose clamps, springs, truck bodies, exhaust manifolds, storage
tanks, pressure vessels and piping.
Table 2.2 General properties of Type 304 Stainless Steel
UNS NO GRADE C Si Mn P S Cr Mo Ni
SS304 304 0.8 1.00 2.00 0.45 0.3 18.00 --- 8.00
Mechanical properties
Table 2.3 Mechanical properties of Type 304 Stainless Steel
UNS NO GRADE Proof stress
(MPa)
Tensile Strength
(MPa)
Elongation Hardness
HB
SS304 304 300 800 50 304
2.7.3 Type 316 Stainless Steel
Type 316 is an austenitic chromium-nickel stainless and heat-resisting steel with
superior corrosion resistance as compared to other chromium-nickel steels when exposed
22. `
22
to many types of chemical corroding agents such as sea water, brine solutions, and the
like.
General Properties of Type 316 Stainless Steel
Type 316 alloy is a molybdenum bearing stainless steel. It has a greater resistance
to chemical attack than the 304 family. Similarly, Type 316 is durable, easy-to-fabricate,
clean, weld and finish.
Chemical composition of SS316
Table 2.4 Chemical composition of type 316
UNS NO GRADE C Si Mn P S Cr Mo
S31609 316H 0.04/
0.10
0.75 2.00 0.030 16.00/
18.00
2.00/
3.00
10.00/
14.00
Mechanical properties
Table 2.5 Mechanical properties of type 316
UNS NO GRADE Proof stress
(MPa)
Tensile Strength
(MPa)
Elongation Hardness
HB
S31609 316H 205 515 40 217
The addition of 2% molybdenum makes 316 considerably more resistant to corrosion and
oxidation than the 304 family of alloys.
Type 316 is considerably more resistant to solutions of sulphuric acid, chlorides,
bromides, iodides and fatty acids at high temperature. In the manufacture of certain
pharmaceuticals, stainless steels containing molybdenum are required in order to avoid
excessive metallic contamination.
2.7.4 Mild Steel
Mild steel is a type of steel that only contains a small amount of carbon and other
elements. It is softer and more easily shaped than higher carbon steels. It also bends a
23. `
23
long way instead of breaking because it is ductile. It is used in nails and some types of
wire; it can be used to make bottle openers, chairs, staplers, staples, railings and most
common metal products. Its name comes from the fact it only has less carbon than steel.
2.7.5 Some Mild Steel Properties and uses
Mild steel has a maximum limit of 0.2% carbon. The proportions of manganese (1.65%),
copper (0.6%) and silicon (0.6%) are approximately fixed, while the proportions of
cobalt, chromium, niobium, molybdenum, titanium, nickel, tungsten, vanadium and
zirconium are not.
A higher amount of carbon makes steels different from low carbon mild-type
steels. A greater amount of carbon makes steel stronger, harder and very slightly stiffer
than low carbon steel. However, the strength and hardness comes at the price of a
decrease in the ductility of this alloy. Carbon atoms get trapped in the interstitial sites of
the iron lattice and make it stronger.
What is known as mildest grade of carbon steel or 'mild steel' is typically low
carbon steel with a comparatively low amount of carbon (0.16% to 0.2%). It has
ferromagnetic properties, which make it ideal for manufacture of many products. The
calculated average industry grade mild steel density is 7.85 gm/cm3. Its Young's
modulus, which is a measure of its stiffness is around 210,000 MPa . Mild steel is the
cheapest and most versatile form of steel and serves every application which requires a
bulk amount of steel.
The low amount of alloying elements, also makes mild steel vulnerable to rust.
Naturally, people prefer stainless steel over mild steel, when they want a rust free
material. Mild steel is also used in construction as structural steel. It is also widely used in
the car manufacturing industry.
Chemical composition of Mild Steel
Table 2.6 Chemical composition of Mild Steel
UNS NO GRADE C Si Mn P S Cr Mo Ni
S31609 316H 0.35/0.45 0.05/0.35 0.6/1.0 0.06 0.06 --- --- ----
24. `
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Mechanical properties
Table2.7 Mechanical properties of Mild Steel
Designation GRADE Yield Stress
(MPa)
Ultimate Tensile
Strength (MPa)
Elongation Hardness
HB
EN8 316H 530 660 7 130
2.8 Temperature Controllers
To accurately control process temperature without extensive operator
involvement, a temperature control system relies upon a controller, which accepts a
temperature sensor such as a thermocouple or RTD as input. It compares the actual
temperature to the desired control temperature, or set point, and provides an output to a
control element. The controller is one part of the entire control system, and the whole
system should be analyzed in selecting the proper controller.
There are three basic types of controllers on-off, proportional and PID. Depending
upon the system to be controlled, the operator will be able to use one type or another to
control the process. An on-off controller is the simplest form of temperature control
device. The output from the device is either on or off, with no middle state. An on-off
controller will switch the output only when the temperature crosses the set point. For
heating control, the output is on when the temperature is below the set point, and off
above set point. Since the temperature crosses the set point to change the output state, the
process temperature will be cycling continually, going from below set point to above, and
back below. In cases where this cycling occurs rapidly, and to prevent damage to
contactors and valves, an on-off differential, or “hysteresis,” is added to the controller
operations. This differential requires that the temperature exceed set point by a certain
amount before the output will turn off or on again. On-off differential prevents the output
from “chattering” or making fast, continual switches if the cycling above and below the
set point occurs very rapidly. On-off control is usually used where a precise control is not
necessary, in systems which cannot handle having the energy turned on and off
frequently, where the mass of the system is so great that temperatures change extremely
slowly, or for a temperature alarm. One special type of on-off control used for alarm is a
limit controller. This controller uses a latching relay, which must be manually reset.
25. `
25
Proportional controls are designed to eliminate the cycling associated with on-off
control. A proportional controller decreases the average power supplied to the heater as
the temperature approaches set point. This has the effect of slowing down the heater so
that it will not overshoot the set point, but will approach the set point and maintain a
stable temperature. This proportioning action can be accomplished by turning the output
on and off for short time intervals. This "time proportioning" varies the ratio of “on” time
to "off" time to control the temperature. The proportioning action occurs within a
“proportional band” around the set point temperature. Outside this band, the controller
functions as an on-off unit, with the output either fully on (below the band) or fully off
(above the band). However, within the band, the output is turned on and off in the ratio of
the measurement difference from the set point. At the set point (the midpoint of the
proportional band), the output on off ratio is 11; that is, the on-time and off-time are
equal. If the temperature is further from the set point, the on- and off-times vary in
proportion to the temperature difference. If the temperature is below set point, the output
will be on longer; if the temperature is too high, the output will be off.
The third controller type provides proportional with integral and derivative control, or
PID. This controller combines proportional control with two additional adjustments,
which helps the unit automatically compensate for changes in the system. These
adjustments, integral and derivative, are expressed in time-based units; they are also
referred to by their reciprocals, reset and rate, respectively. The proportional, integral and
derivative terms must be individually adjusted or “tuned” to a particular system using trial
and error. It provides the most accurate and stable control of the three controller types,
and is best used in systems which have a relatively small mass, those which react quickly
to changes in the energy added to the process. It is recommended in systems where the
load changes often and the controller is expected to compensate automatically due to
frequent changes in set point, the amount of energy available, or the mass to be
controlled. Because of the above advantages PID controller is used for maintaining
temperature in the range i.e. (88±2)oc.
26. `
26
2.9 Flow meter
Measuring the flow of liquids is a critical need in many industrial plants. In some
operations, the ability to conduct accurate flow measurements is so important that it can
make the difference between making a profit and taking a loss. In other cases, inaccurate
flow measurements or failure to take measurements can cause serious (or even disastrous)
results.
With most liquid flow measurement instruments, the flow rate is determined
inferentially by measuring the liquid's velocity or the change in kinetic energy. Velocity
depends on the pressure differential that is forcing the liquid through a pipe or conduit.
Because the pipe's cross-sectional area is known and remains constant, the average
velocity is an indication of the flow rate. The basic relationship for determining the
liquid's flow rate in such cases is
Q = V x A
where,
Q = liquid flow through the pipe
V = average velocity of the flow
A = cross-sectional area of the pipe
Other factors that affect liquid flow rate include the liquid's viscosity and density, and the
friction of the liquid in contact with the pipe.
Direct measurements of liquid flows can be made with positive-displacement flow
meters. These units divide the liquid into specific increments and move it on. The total
flow is an accumulation of the measured increments, which can be counted by mechanical
or electronic techniques. The performance of flow meters is also influenced by a
dimensionless unit called the Reynolds Number. It is defined as the ratio of the liquid's
inertial forces to its drag forces.
Reynolds Number = Inertial Forces/Drag Forces
=
𝜌𝑉𝐿2
µ𝑉𝐿
=
𝜌𝑉𝐿
µ
27. `
27
Where,
ρ=Density of liquid
V=Velocity of liquid
L=Critical Length for the surface where liquid flows
µ=Dynamic Viscosity of liquid
2.9.1 Paddlewheel Flow Meter
Paddlewheel flow meters have a paddle wheel that is perpendicular to the flow
path. The rotor axis is positioned to limit contact between the paddles and the flowing
media. There are many different types of paddlewheel flow meters. Examples include gas
flow meters, air flow meters, liquid flow meters, and water flow meters.
Figure 2.12 Construction Details of Flowmeter
A gas flow meter is used to determine the flow of a moving gas in an enclosed
pipe or passage. An air flow meter is used to measure airflow rate by measuring only a
part of the entire flow. A liquid flow meter is used to determine the flow of quantity of a
moving fluid. A water flow meter is designed to measure the flow of water. Paddlewheel
flow meters carry physical, media and operating specifications, and differ in terms of
output options and features.
28. `
28
3. Major Components of the Test Rig
The Circulating coolant corrosion test rig has components some of which have
been defined by the standards while others which are to be built as per requirement.
3.1 Engine and Pump assembly-The centrifugal pump is used to pump the coolant into the
tank.
Figure 3.1 Engine and pump assembly
The Engine and water pump have following specifications
Make of Engine -Tata Motors
Type of Engine - 4 cylinder inline Tata Indica petrol
Make of water pump -Tata Motors
Type of water pump - Centrifugal water pump
29. `
29
3.2 Motor-The motor drives the pulley.
The used motor has following specification
Make of motor -Siemens
Power Rating -1HP
RPM -1440
Number of poles - 6
Type of Mounting -Foot Mounting
Figure 3.2 Motor
3.3 Cylinder Tank-The cylinder tank houses the coolant and also houses the test
specimens.
Figure 3.3 Cylinder Tank
30. `
30
The Cylinder has following specifications
Material of Cylinder - Stainless Steel 316
Capacity of Cylinder - 7 Litres
3.4 Radiator-The coolant flows from the tank through the flow-meter into the radiator.
The radiator here is only used to simulate the actual conditions as much as possible. The
radiator is only used to make the actual simulation as real as possible.
Figure 3.4 Radiator
The Radiator has following specifications
Make - Maruti Suzuki
Type of core -Tubular core with Surpentine fins
Material of tubes - Copper
No. of tubes -24
3.4 Heater-The band type heater attached on the periphery of the cylindrical bath heats
the coolant to required temperature. These heaters are used as we need indirect type of
heating and as a result insertion types of heaters are not used.
The heater has following specifications
Type of heater -Ceramic Band Heater
31. `
31
Power Rating - 1.5 KW
Type of clamping system -Alan Bolts
Type of heating element -Nickel Chrome wire
Figure 3.5 Band Heater
3.5 Coolant Reservoir-The coolant reservoir is a cylindrical vessel with level sensors that
contains the coolant. This coolant is fed externally to the radiator as per requirement.
The coolant reservoir also has a level sensor directly connected to the electric panel so
as to measure the level of coolant in it in case it is depleted.
Figure 3.6 Reservoir tank
32. `
32
The coolant reservoir has following specification
Material -Stainless Steel
Capacity of reservoir - 3 litres
3.6 Flow-meter-The flow-meter is used to measure the flow rate. It should be noted that the
flow-meter only measures the flow and does not regulate it to 60LPM.
Figure 3.7 Flow-meter
The Flowmeter has following specifications
Make - VatturkarFlowmeters
Type of Flowmeter - Paddle wheel inline Flowmeter
Range of Velocity measurement -0.5m/sec to 5m/sec
Accuracy - +/- 1% of full scale deflection
Input Voltage - 3.4 to 24 Volts
Output Voltage - Sinking square wave 30-35Volts
Protection Rating - IP 67
3.8 PID controller-The PID controller, placed in the cylinder tank is used to regulate the
temperature. It turns on or off the heater as per the requirement to maintain the coolant
temperature in the range as per the standards.
33. `
33
The PID has following specifications
Temperature Range -(-)100⁰C to 250⁰C
Accuracy - IEC 751 1983
Connection Head - Heavy duty aluminium
Conduit Head - M20, PG 13.5” or 16”, 1/2” NPT
Thermal well - Stainless steel
Installation Thread -1/2” BPS. Tr, 1/2” NPT
Terminations -Threaded
Cable Entry(3 core) - 4 to7 mm diameter,2 to 6 gauge
Heat Transfer Compound -Silicon
Figure 3.8 PID Controller (Temperature Sensor)
3.9Control Panel-The control panel houses the all the hard electric wiring and displays for
voltage in each line.
The control Panel comprises of the following features
Full voltage non-reversing and full voltage reversing starters
AC variable frequency drives
34. `
34
Solid-state motor controllers
Lighting panels
PLC I/O chassis
Transformers
Analog or digital metering
Feeder circuit breakers
Feeder fusible disconnects
Figure 3.9 Control Panel
3.10 Touch Screen Panel.-The touch screen panel houses the touch screen and the also an
emergency stop button.
Figure 3.10 Touch screen
35. `
35
The Delta Touch screen has following features
3 sets of COM ports, support RS232/RS422/RS485
For data transfer/download RS232, USB and Ethernet.
Supports USB host, direct connection to USB disk, printer and mouse.
Supports SD card, Ethernet.
Touch Screen complies with IP65.
Editing software, DOPSoft is compatible with operating systems Windows XP,
Windows Vista, Windows 7.
3.11 Pulley-The Aluminium pulley drives the water pump via a timing belt.
Figure 3.11 Pulley
The Pulley has following specifications
Pitch circle Diameter (PCD) = 189mm
No. of teeth = 80
Material -Aluminium
Mass of pulley =2.3kg
36. `
36
3.12 Frame-The frame of the rig houses all the above components.
The Frame has following specifications
Types of links - 40mm X40mm square pipes
Number of pipes required -13
Dimensions - 1100mmX1000mmX650mm
Material -Mild Steel
Figure 3.12 Frame for mounting the components
37. `
37
4. Analysis of Various Components
4.1Cylinder Tank Analysis
Amount of coolant should be there in tank while process cycle is 7±1 litres (according to
IS 5759)
Length of the test specimen strip to be inserted in the tank is 225mm.
So length of the tank selected for convenience of flow around test specimen is 250mm.
Volume of tank (Vt)
Vt=7liters (ideal case)
Vt=7*10-3 m3
Also volume of tank
Vt=
πd2 L
4
(1)
Vt=7*10-3=
πd2
4
*0.250
By solving equation;
d =184.54mm
d=185mm (approx. for manufacturing purpose)
Material chosen for tank is SS316 for the following advantages over other grades
Type 316 has higher carbon content which makes it suitable for use in applications where
elevated temperature is present.
This increased carbon content delivers a greater tensile and yield strength. The
austenite structure material also gives grade excellence toughness, even down to
cryogenic temperature.
38. `
38
316 Stainless Steel offers a reduced risk to stress corrosion cracking, improved creep
resistance, and better protection against pitting and crevice corrosion.
Figure 4.1 Tank Assembly in CATIA
316 (an addition of an extra 2 - 3% molybdenum and nickel), has enhanced corrosion
resistance suitable for more aggressive atmospheric environments, is anti-allergenic,
requires low maintenance and suitable for all cleaning solutions including acid based
(except hydrochloric acid), as long as thoroughly rinsed with clean water afterwards.
4.2 Heater Analysis
Relevant data
Density (ρ) = 1054 kg/m3
Specific Heat Capacity (Cp) =2.728 kJ/kg-K
Viscosity (µ) = 0.278x10-2 N-s/m2
Thermal Conductivity (K) =261x10-3 W/m-K
Flow Rate (Q) =60LPM=1LPS=0.001 m3/s
39. `
39
Calculations
Cross-sectional area of tank (A)
A=
πd2
4
(2)
A=
π
4
x (0.185)2
A=0.02688m
Discharge (Q)
Q=AxV (3)
Hence,
Velocity of flow (V)
V=
𝑄
𝐴
V=
0.0010
0.02688
V = 0.037 m/s
Reynolds’ number (Re)
Re=
𝜌𝑉𝐿
µ
(4)
Re=
(1054x0.037x0.185)
0.278 x0.001
Re = 2595.1
This value of Reynolds’ number signifies laminar flow
Prandtl number (Pr)
Pr=
Cpµ
K
(5)
40. `
40
Pr=
(2.728𝑥0.278𝑥10−2)
261𝑥10−3
Pr= 0.029
Nusselt number (Nu)
Since it is a heating application,
Nu=0.023x (Re0.8Pr0.4) (6)
Nu=0.023 x (2591.40.80.0290.4)
Nu= 3.01
Stanton number (St)[5]
Heat transfer coefficient (h)
h =
Nu
RexPr
x ρ x V x Cp (7)
h=
3.01
2595.1𝑥0.029
x 1024 x 0.037 x 2.728
h = 4.12 kW/m2K
Power required
P= h x Ab x ΔT (8)
where, ΔT= (88+2) =4°C
Area of Band heater
Ab= π x db x H (9)
Ab=πx0.185x0.0762
Ab= 0.044m2
Diameter (db) of the heater will be the diameter of the tank which is 185mm, and the
height (H) is assumed to be 3 inches by space considerations and to minimise heat losses.
41. `
41
Hence,
P=4.12*0.044*4
P= 0.73kW
This is the power input required to maintain the temperature of the circulating coolant
inside the tank. Assuming 30% of the heat is lost, we select a band heater of 1.5kW.
Hence the power lost is 0.6kW and the power required is 0.73kW.
Energy Balance
Power Rating = Power in to system + Power Lost + Surplus
1.5 =0.7 +0.6 +0.17
4.3 Water Pump Analysis
The pump used in the rig is a standard Tata Indica centrifugal water pump. This
pump is attached to the motor of 1hp via a standard belt drive. From Tata motors
catalogue, the speed at which the pump must run to achieve 70LPM discharge is 6000rpm
Relevant Data
Full Load Motor efficiency from Siemens Catalogue (ηm) =80.5%
Transmission efficiency for 6000 rpm (ηt) =95%
Pipe Diameter (dp) =25.4mm=0.0254m
Discharge (Q) =60LPM=1000000mm3/sec
Length of Suction pipe (Ls) =210mm=0.210m
Solution
Velocity of Flow through Suction and Delivery Pipe
Vs=
Q
Ac
(10)
42. `
42
Where,
Ac=Cross Section area of pipe
Ac=
πdp
2
4
(11)
Ac=
π (25.4)2
4
Ac=506.7mm2
Vs=
1000000
506.7
Vs=1973.5mm2
Manometric Head= Suction Lift +delivery lift+ Velocity heads
We neglect minor frictional losses and losses due to bents and elbows
Hm= hs + hd+ hvs+ hvd (12)
hs=Suction Lift=210mm (Length of suction pipe excluding length of elbows)
hd=Delivery lift=0 (Pump shall be delivered fluid above its own datum)
Velocity head at suction pipe (hvs)
hvs= Vs /2g
hvs=1973.5/2 x 9.81
hvs=100.58mm
Velocity head at delivery pipe (hfd)
As the suction and delivery pipe diameters are same, the value of velocity head is also
same.
had=100.58 mm
43. `
43
Hm=210+0+100.58+100.58
Hm=411.16 mm
Figure 4.2 Various heads in pump and its component
4.4 Pulley and Timing Belt Analysis
Relevant Data
Required Gear Ratio (G) =6000/1440≈4
Pitch Circle Diameter of Pump (d) =47mm
Pitch Circle Diameter of Pulley (D) =47 x 4=188mm
44. `
44
Centre to centre distance of Pulley and Pump(C)
L=2C+
π (D+d)
2
+
(D-d) 2
4C
(13)
Where, L=1171mm
D=188mm
d=47mm
∴ C=390mm.
Distance Chosen=375to405mm.
Figure 4.3 Pulley Drawing in CATIA
45. `
45
5. Final Assembly
The final assembly of the rig took place in the following manner
1) Mount the engine head, water pump and block assembly on the welded platforms
2) Mount the motor on the corresponding welded platforms
3) Mount the timing belt on the pump and motor
4) Mount the radiator on the C-bracket
5) Place the tank on the platform with proper orientation of the pipes
6) Attach the delivery pipe from the delivery port of the engine to the inlet port of the
tank
7) Use rubber hoses and circlips for proper sealing and to ensure a flexible connection
8) Connect the output pipe of the tank to the flowmeter.
9) The output pipe and inlet of the flowmeter are flanged together
10) Connect the output pipe of the flowmeter to the inlet of the radiator
11) Use rubber hoses and circlips for proper sealing and to ensure a flexible connection.
12) Connect the outlet port of the radiator to the suction port of the engine block
13) Mount the electric box
14) Place the garnering tray at the bottom
15) Attach the side enclosure panels
16) Attach the back enclosure panels
17) Mount the fan into the back enclosure panel
18) Attach the top enclosure panel
19) Screw the telescopic hinges into the top part of the frame
20) Attach the corresponding top door
21) Mount the control panel on the top panel
22) Mount the reservoir tank on the top panel
23) Connect the reservoir tank to the radiator via a rubber tube
24) Attach the heater on the periphery of the cylinder tank
25) Connect the heater to the electric box
26) Connect the motor to the electric box
46. `
46
6. Experimental Setup
AIM: Develop a rig to test the effects of coolants on various engine materials or vice
versa.
APPARATUS
Assemble the apparatus using the following implements, and the total amount of test
solution shall be 12±4 litre
The test rig setup (fig 6.1 ) should consists of heating bath, circulating pump, and
radiator assembly for evaluating the effects of engine coolant on metal specimens by
circulation continuously for specified period under controlled laboratory conditions
Figure 6.1 Test rig setup
It should be a floor mounted bench and should comprise of following
Heating Bath
Material Stainless Steel (SS‐316)
Cylindrical type of capacity 7 +/‐ 1 Lit.
Heating arrangement from outside the bath.
47. `
47
Figure 6.2 Heating arrangement
The bath should be capable of accommodating 3 Nos. of test specimen assembly (Fig.
6.2) with a convenient provision for the loading and removal of the test specimens from
the tank.
There should be a single valve to drain-off the coolant of the entire system.
Shelf plate made of SS and insulated with a synthetic resin spacer.
Figure 6.3 Arrangement of test specimens
48. `
48
Water Pump
Standard Automobile Centrifugal pump to be provided with a casing made of
aluminium casting and with vanes made of steel or cast iron and mounted on the fluid
tank. There should be a bleeding system incorporated in the system for efficient working
of the pump.
Radiator
Standard aluminium or brass automobile radiator, with a reserve tank (for coolant
recovery) and level indicator. The reserve tank should be made of SS/PP with a capacity
of about 1 L. Radiator Pressure Cap to be provided.
Upper hose and Lower hose
Rubber hoses provided in line for the circulation of coolant in the system should
be of heavy-duty, automobile industry quality.
Connecting tube
The connecting tubes used to connect the fluid tank, flow-meter, filter and the
heating bath should be made of stainless steel (SS304).
Temperature Controller
Time‐Proportionating type controller to be provided to maintain the temperature
of the bath at 88 +/‐ 2oC to be provided. RTD type temperature sensor probe dipped in the
bath from the top.
Time Totalizer
Time totalizer to be provided to set and control the test duration by setting the
time.
Flow controller/indicator
Digital type flow measuring/indicating device with sensor to be provided to
control the flow rate at 60+/- 10lpm.
Filter is to be provided to avoid the dust getting circulated in the system.
49. `
49
Frame work
All the components should be mounted on a sturdy framework and assembled in a
ground mounted enclosure. Suitable ventilating system consisting fan and other
accessories should be provided to avoid excessive heating of the equipment.
Pulleys and Drive belt
The pulley and belt system to be provided to couple the motor and the pump to
produce a flow rate as per the standard requirement.
Control Panel
Control panel should house controller and indicators units, relays, MCBs, standard
wires and cabling, etc.
It should have provision for-
ON/OFF switches for the system, heater, etc.
Digital controller for temperature with set point and continuous display;
Time-totalizer with set point and continuous display;
Digital flow indicator.
Spares and consumables
Pulley Belt -2 sets
Set Of Gaskets -2 sets
Circulating Pump -2 sets
Heater Element -1 set
Rubber Hoses -2 sets
Electrical
Voltage of Power Supply 230 +/- 10 % V and Frequency of Power supply 50 +/- 2 Hz
50. `
50
6.1 Parameters to be Achieved
Table No.6.1 Test Conditions as per IS and JIS
Sr NO. ITEM CONDITION
1 Concentration of test solution 30 volume, percent test solution
2 Temperature of test solution 88±3⁰C
3 Flow Rate 60±10 LPM
4 Operating hours 1000±2 hrs (continuously)
6.2 Process Flow Table
Table No.6.2 Process Flow Table
Sr.NO. ENTITY PROCESS DETAILS
1 Frame Marking and Sizing of square
pipes.
2 Frame Cutting.
3 Frame Positioning and welding.
4 Ribs Sizing and cutting ribs
Ribs Welding ribs to the frame.
Ribs Drilling for outer enclosure bolting.
5 Frame Base Sheet Cutting.
6 Frame Base Welding the base to the frame.
7 C-Brackets (for Radiator
mounting)
Sizing and cutting.
8 C-Brackets (for Radiator
mounting)
Welding to form a “C”
9 C-Brackets (for Radiator
mounting)
Marking and welding to the frame.
10 C-Brackets (for motor and
engine block mounting)
Sizing and cutting.
51. `
51
11 C-Brackets (for motor and
engine block mounting)
Welding to form a “C”.
12 C-Brackets (for motor and
engine block mounting)
Marking and welding to the frame
base
13 All C-Brackets Marking and drilling through holes
of required diameter according to
the constraints of radiator, engine
and motor.
14 Brackets for control panel
mounting.
Sizing, cutting, drilling (for
bolting) and welding to the frame.
15 Stand for testing tank Sizing and cutting of square pipe.
16 Base for testing tank Sizing and cutting of sheet metal.
17 Ribs for the stand of testing
tank.
Sizing and cutting of sheet metal
18 Stand Welding stand assembly to frame.
19 Tank Sheet Metal (SS316) rolling and
MIG welding.
20 Tank Flange Sizing Cutting tank flange from
SS316.
21 Tank Flange Drilling holes in the flange at
specified PCD and of reqd.
diameter.
22 Tank Flange Welding flange to the tank.
23 Lid flange Sizing and cutting of lid flange
from SS316.
24 Lid Flange Drilling holes at a specified PCD
and of reqd. diameter.
25 Lid Flange Sizing and punching a hole for the
lid to which the test pieces are to be
attached.
26 Lid Sizing and cutting of a lid from
SS316.
27 Tank brackets Sizing, cutting and welding
brackets to ensure fixing of tank on
the tank stand.
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28 Cladding Sizing, cutting, bending of MS of
reqd. dimensions for door opening
and other enclosures.
29 Cladding Marking and drilling on cladding
for fixing them on the frame.
30 Cladding Marking and drilling for locks,
hinges and for hard wiring.
31 Powder Coating Powder coating of the welded
structure and the separate parts
(Control panel and the touch screen
box)*. Colours are specified by the
authorities.
32 Assembly Assembling, tank, motor, engine
block, control panel, touch screen
panel, locks etc.
33 Piping Piping, connecting flow meter in
the fluid circuit, also providing
extra tappings.
34 Coolant Reserve tank. SS316 sheet metal rolling and
bolting it to the frame from top.
35 Cladding Bolting and hinging the doors and
the enclosures as per requirement.
*The panels were bought.
The above table shows the generic processes followed during manufacturing of the test
rig.
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6.3 Bill of Materials
Table No.6.3 Bill of Materials
Sr
No
Component Quantity Material Remarks
1 Motor
1.1 1 HP Siemens 3phase 1440rpm 1 std std
1.2 M8X25 bolts Hex head 4 M.S For mounting of motor
1.3 M8 nuts 4 M.S For mounting of motor
1.4 M8 washers 4 M.S For mounting of motor
1.5 M8 spring washers 4 M.S For mounting of motor
1.6 M10 bolt 1 M.S For tensioning of motor
1.7 M10 nut 1 M.S For tensioning of motor
2 Engine with Water Pump Assembly*
2.1 Tata Indica water pump 1 std std
2.2 M6x20 bolts Hex head 5 M.S For mounting of pump
2.3 M6 washers 5 M.S For mounting of pump
2.4 M6 spring washers 5 M.S For mounting of pump
2.5 Tata Indica engine block 1 std std
2.6 Tata Indica engine head 1 std std
2.7 M8x25 bolts Alan head 8 M.S For mounting of engine
2.8 M8 nuts 8 M.S For mounting of engine
2.9 M8 washers 8 M.S For mounting of engine
2.11 M16x20 bolts Hex head 2 M.S For plugging in engine
2.12 M18x20 bolt Hex Head 1 M.S For plugging in engine
3 Tank and Flanges
3.1 Tank I.D=185mm,H=248mm 1 S.S std
3.2 M8x25 bolts Alan Head 8 S.S For the lid of the
cylinder
54. `
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3.3 M8x25 nuts 8 S.S For the lid of the
cylinder
3.4 M8 washers 8 S.S For the lid of the
cylinder
3.5 M6x25 bolts Allen Head 15 S.S For mounting of
cylinder, for cover
containing test stripes
for flanges
3.6 M6x25 nuts 11 S.S For mounting of
cylinder, for flanges
3.7 M6 washers 15 S.S For mounting of
cylinder, cover
containing test strips
4 Radiator
4.1 Radiator Maruti 800 1 std std
4.2 M6x35 bolts Hex head 4 M.S For mounting of
radiator
4.3 M6x35 nuts 4 M.S For mounting of
radiator
4.4 M6 washer 4 M.S For mounting of
radiator
4.5 Temperature Sensor 1 std Plugging of radiator
5 Piping
5.1 M8x25 bolts Allen
Head+nuts+washer
3 M.S Suction line connection
5.2 M6x25 bolts Allen
Head+nuts+washer
3 M.S Delivery Line
connection
6 Electric Box
6.1 M10x25 bolts Hex
head+nuts+washer
4 M.S For mounting of
electric box
7 Control Panel
7.1 M6x30 bolts Hex head+washer 4 S.S For mounting of control
panel
7.2 M6x20 bolts Star head+washer 4 S.S For mounting of touch
screen
55. `
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8 Enclosure Panels
8.1 M6x20 bolts Chiselled
head+washer
14 S.S For fitting of enclosure
panels
9 Hinges
9.1 Hinges 50mmx50mm 6 C.I Std
9.2 Hydraulic Hinges unbound
length=250mm
2 std std-Self supporting
9.3 M6x15 bolts Chiselled
head+nuts+washer
12 S.S For fitting of hinges
9.4 M6x50 bolts Chiselled
head+nuts+washer
12 S.S For fitting of hinges
10 Plugs
10.1 1/2" plug 2 S.S Delivery line tappings
10.2 3/4' plug 1 S.S Suction line tapping
10.3 1/2"plug Collar head 2 M.S Tank tapping
11 Reservoir
11.1 Cylindrical Reservoir 1 S.S std
11.2 M6x25 bolts chiselled
head+washer
2 M.S For mounting of
reservoir
12 Wheels
12.1 Fixed Wheels 2 std std
12.2 Moving Wheels 2 std std
12.3 M10x50mm bolts Hex head 4 M.S For mounting of wheels
13 Fan
13.1 Light duty fan 1 std Std
13.2 M4x50 bolts chiselled
head+nuts+washer
4 S.S For mounting of fan
14 Miscellaneous
14.1 1/2" air breather 1 M.S For reservoir
14.2 3/4" release valve 1 std Fit into suction line
56. `
56
14.3 Circular door locks 4 std std
14.4 Recess handles (110mm x
55mm)
3 Plastic std
14.5 Circlips 6 std std
14.6 Silicon Gasket 1 silicon std
14.7 Hose I.D=1" rubber std
14.8 Araldite 1 std std
14.9 Square pipes 40mm x 40mm M.S For construction of
frame
14.10 Pulley Φ185mm x 30mm 1 Al Driving water pump via
belt
* Screws for fixing engine head and engine block are standard issue TATA
motors components hence not included above.
** Screws for the flowmeter are a standard issue hence not included above.
58. `
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6.5 Maintenance
The new coolant corrosion test rig has been designed so as to guarantee maximum
safety features and minimum human intervention on human part. Nonetheless to ensure
smooth working of the rig over a long period of time, some basic maintenance must be
done from time to time.
1) The coolant flows continuously in the circuit. The steel pipes though made of SS316
will undergo corrosion due to constant exposure to the coolant. The pipes hence must
be disconnected after one cycle of operation and be cleaned. This will ensure the
longevity of the pipes
2) The paddle wheel of the flowmeter must also be cleaned vigorously after one cycle of
operation
3) The calibration of the flowmeter must be done once per two-three cycles of operation
to maintain its accuracy
4) Leakage checks must be made regularly.
5) The gathering tray must be regularly cleaned.
6) The inner side of the heater must be cleaned to ensure proper contact with the cylinder
tank.
59. `
59
7. Conclusion
The new setup has achieved the new parameters successfully. The variation of the
discharge is within limits of 50 to 70 LPM. The new rig has achieved standards
prescribed by the Indian and Japanese standards.. Moreover the newer test rig has safety
features like a complete enclosure, emergency stop switch and alarming systems which
ensure a decent degree of safety. Being highly compact, it has also provision for moving
the test rig, implying easy to transport. The test rig is highly ergonomic and does not
need a high skilled operator.
Graph 1 Temperature V/s Time
The graph of Temperature Vs Time shows a linear variation. The exponential rise at the
at the beginning is due to the cold start from the room temperature. The graph proves that
the results are within limits and the required parameters of 88±2 0c has been achieved.
The PID controls the turning on and off of the heater to maintain the temperature within
88-92 range. This graph also showcases us that the PID controller and the heater are
24
28
32
36
40
44
48
52
56
60
64
68
72
76
80
84
88
92
0 50 100 150 200 250 300
Temperature(oc)
Time Completed (Hrs)
Graph of Temperature Vs Time
60. `
60
working in accordance with requirements. We can hence conclude that both the heater
and the PID are working correctly.
Graph 2 Discharge V/s Time
The graph of Discharge Vs Time showcases a linear variation within the required range of
50-70 LPM. Compared to the old setup, it is observed that the fluctuation of discharge
with respect to time is less. This is because in the new rig we have used a timing belt
rather than a simple belt. This has reduced the variation in discharge.
0
8
16
24
32
40
48
56
64
72
0 24 48 72 96 120 144 168 192 216 240 264 288
Discharge(LPM)
Time Completed (Hrs)
Graph Of Discharge V/s Time
61. `
61
8. Cost Analysis
Table 8.1Cost Analysis
NO PART/PROCESS COST
1 Engine block and engine head of TATA Indica 51000/-
2 Fabrication of frame 21000/-
3 Powder coating of frame 5000/-
4 Control panel with software 50000/-
5 Electric motor 5500/-
6 TATA Indica water pump 953/-
7 Heating tank manufacturing (SS316) 4900/-
8 Band heater 1500/-
9 Pulley manufacturing 8000/-
10 Timing belt TATA Indica diesel 1250/-
11 Electronic Flow meter with indicator 30000/-
12 PID 2500/-
13 Level sensor 2000/-
14 Touch screen 15000/-
15 Other hardware(bolts, nuts, washers, plugs, rubber pads,
asbestos sheets, breathers, pipes, flanges, electric
connections)
7000/-
TOTAL 205603/-
62. `
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9. Future Scope
The Coolant corrosion test rig is a definite improvement on the old setup. The new
test rig is capable of running for the required 1000hrs without problems. This test current
rig is built to house a four cylinder inline engine. For next rig we can easily include a
heavy duty truck engine and verify the coolant performances.
In the new setup we encountered problems regarding the amount of vibrations
once the rig started. To avoid this in the future we can use either enclosure panels of a
stiffer material than mild steel or rubber anti vibration pads can be glued to the inner side
of the enclosure panels. This option though easy will to some extent reduce the aesthetical
appeal of the rig and will also increase chances of the motor overheating. Motor
overheating can be avoided by fitting a small light duty fan to avoid the overheating of
the motor. To get an accurate discharge of only 60LPM, the use of a flow regulator rather
than flow meter is suggested. Flow regulators fulfil the dual purpose regulating and
measuring the flow. Problems have also been encountered regarding the fitting of the PID
controller and to avoid this it is mandatory that the future setup has more leeway in the
vertical direction.
The radiator in the current rig is a just a device fitted to make the simulation as
real as possible. However we can check the performance of the radiator as there are
tappings made both in the inlet and outlet line to measure the temperature. This will also
give us an idea of the radiator performance. Similarly we can compare performance of
various radiators by this methodology and it will only require the fitting of a bigger C-
bracket to house the radiators.
10. References and Bibliography
63. `
63
[1].R.C. McCune,Encyclopaedia of Materials Science and Technology (Second
Edition), 2001, G.A. Webe, Pages 426-434
[2]. Dr. Kirpal Singh, Standard PublishersAutomobile Engineering ,Volume 1(12th
Edition),2001, Pages 504-514
[3].Dr. Kirpal Singh, Standard Publishers, Automobile Engineering,Volume 2(12th
Edition),2001, Pages 158-179
[4].Peyghambarzadeh , S.H. Hashemabadi , S.M. Hoseini , M. SeifiJamnani,
Experimental study of heat transfer enhancement using water/ethylene glycol
based nanofluids as a new coolant for car radiators, July 2011.
[5].Frank P. Icropera, David P.Dewitt, Fundamentals of Heat and Mass
Transfer,(Fifth Edition),2011, Wiley Student Edition, Pages 356-363,922
[6].V B Bhandari, Tata McGraw Hill Publications, Design of Machine Elements, (3rd
Edition), 2012, Page 511.
[7]. IS 5759:2006, Circulating Corrosion Property, Annex R, Page 35- 38?
