vapor absorption system,three fluid vapor absorption system,water and ammonia vapor absorption system water and lithium bromide vapor absorption system
introduction of VARS,refrigrants properties,cop,practical VARS ,
Simple VARS,advantages of VARS,comparison of vars with vcrs,Refrences of VARS,Refrigration cycles,economical system,absorbent properties
The ppt contains detailed study of Vapor Absorption Refrigeration System with neat sketches and description. It is well formed as per the syllabus of GTU
introduction of VARS,refrigrants properties,cop,practical VARS ,
Simple VARS,advantages of VARS,comparison of vars with vcrs,Refrences of VARS,Refrigration cycles,economical system,absorbent properties
The ppt contains detailed study of Vapor Absorption Refrigeration System with neat sketches and description. It is well formed as per the syllabus of GTU
Aircraft refrigeration system (air cooling system)Ripuranjan Singh
Aircraft air refrigeration systems are required due to heat transfer from many external and internal heat sources (like solar radiation and avionics) which increase the cabin air temperature. With the technological developments in high-speed passenger and jet aircraft's, the air refrigeration systems are proving to be most efficient, compact and simple. Various types of aircraft air refrigeration systems used these days are.
Simple air cooling system
Simple air evaporative cooling system
Boot strap air cooling system
Boot strap air evaporative cooling system
Reduced ambient air cooling system
Regenerative air cooling system
COMPRESSOR EFFICIENCY AND TURBINE EFFICIENCY.
Comparison of Various Air Cooling Systems used for Aircraft ON basis of dart
STEAM JET COOLING SYSTEM
Steam jet cooling system is a cooling technique which involves usage of steam and water for cooling purposes. In steam jet refrigeration systems, water can be used as the refrigerant. Like air, it is perfectly safe. These systems were applied successfully to refrigeration.
•Temperatures attained using water as a refrigerant are in the range which may satisfy air conditioning, cooling, or chilling requirements.
•Mostly low-grade energy and relatively small amounts of shaft work.
•This system are the utilization of mostly low-grade energy and relatively small amounts of shaft work.
•Not used when temperatures below 5°C are required.
Aircraft refrigeration system (air cooling system)Ripuranjan Singh
Aircraft air refrigeration systems are required due to heat transfer from many external and internal heat sources (like solar radiation and avionics) which increase the cabin air temperature. With the technological developments in high-speed passenger and jet aircraft's, the air refrigeration systems are proving to be most efficient, compact and simple. Various types of aircraft air refrigeration systems used these days are.
Simple air cooling system
Simple air evaporative cooling system
Boot strap air cooling system
Boot strap air evaporative cooling system
Reduced ambient air cooling system
Regenerative air cooling system
COMPRESSOR EFFICIENCY AND TURBINE EFFICIENCY.
Comparison of Various Air Cooling Systems used for Aircraft ON basis of dart
STEAM JET COOLING SYSTEM
Steam jet cooling system is a cooling technique which involves usage of steam and water for cooling purposes. In steam jet refrigeration systems, water can be used as the refrigerant. Like air, it is perfectly safe. These systems were applied successfully to refrigeration.
•Temperatures attained using water as a refrigerant are in the range which may satisfy air conditioning, cooling, or chilling requirements.
•Mostly low-grade energy and relatively small amounts of shaft work.
•This system are the utilization of mostly low-grade energy and relatively small amounts of shaft work.
•Not used when temperatures below 5°C are required.
SOLAR POWER VAPOUR ABSORPTION REFRIGERATION SYSTEMaj12345ay
USE OF SOLAR POWER IN REFRIGERATION SYSTEM
The power incident from the sun to the earth has very much amount of energy that the present consumption rate of all the commercial and general uses. We utilize only 0.1% of total incident sun energy on the surface of earth. Thus solar energy can fulfill our present as well as future needs of energy. That is a reason it called renewable sources of energy. It is also environmental clean source of energy and available at whole part of world where people live. Using of solar energy in the field of refrigeration and air conditioning system it become very economical.
In our project we provide solar heat in generator for heating purpose of vapor compression refrigeration system.
For past few decades, energy has played a prominent role in the development of technology and economy. Energy has now become inevitable factor for production as well. The objective of this project is to develop an environment friendly vapour absorption system. Vapour absorption system uses heat energy, instead of mechanical energy as in vapour compression system, in order to change the condition of refrigerant required for the operation of the cycle. R 717(NH3) and water are used as working fluids in this system. The basic idea of this project is derived from the solar heating panel to obtain heat energy, instead of using any conventional source of heat energy. In this project various observations are done by varying operating conditions related to heat source, condenser, absorber and evaporator temperatures. The drawback of this system is that, it remains idle in the cloudy weather conditions.
COMPONENTS USED IN SOLAR POWERED AQUA-AMMONIA VAPOUR ABSORPTION SYSTEM
• ABSORBER
• PUMP
• HEAT EXCHANGER
• GENERATOR
• SOLAR PANEL
• CONDENSER
• EXPANSION VALVE
• EVAPORATOR
• DC BATTERY
• FAN
Les vaporisateurs, lorsqu’ils sont de grande qualité comme ceux que vous trouverez sur le site de Magic Vaporizers, sont un excellent moyen de se soigner grâce aux médecines douces. Visit https://magicvaporizers.fr
It will help to the students of Mechanical Engineering. These notes are according to HVAC Subject. Some important topics are here for your good understanding. These are written in easy language, u can understand easily.
Generation of Air Conditioning by using Exhaust Gases and Cooling Water of an...ijtsrd
Air conditioning system of car or buses works on principle of vapor absorption cycle of refrigeration VAR . This system reduces the fuel economy of fuel of vehicle. When vehicle moving with air conditioning, it consumes more amount of fuel than vehicle rubs without AC, typically, it consumes 15 to 20 more amount of fuel. Exhaust gases coming from engine of vehicle have temperature ranges to 300 to 400 degree centigrade at full load it carries 25 to 30 of heat supplied by fuel. For A.C. of an automobile, the heat of exhaust gases is utilized to run vapor absorption refrigeration cycle instead of vapour compression refrigeration system. Resulting, it improves fuel economy of A. C. heavy vehicle. In this project try to integrate the vapor absorption refrigeration system with car or bus or heavy vehicle engine exhaust. Comparative study has been carried out when car running with VCR and vapor absorption system of refrigeration. Dr. M. Sampath Kumar | Karthik Payam | Rajesh Medi | Srikanth Chennam | Aditya Mothukuri ""Generation of Air Conditioning by using Exhaust Gases and Cooling Water of an Automobile Engine"" Published in International Journal of Trend in Scientific Research and Development (ijtsrd), ISSN: 2456-6470, Volume-3 | Issue-3 , April 2019, URL: https://www.ijtsrd.com/papers/ijtsrd23318.pdf
Paper URL: https://www.ijtsrd.com/engineering/mechanical-engineering/23318/generation-of-air-conditioning-by-using-exhaust-gases-and-cooling-water-of-an-automobile-engine/dr-m-sampath-kumar
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
Vaccine management system project report documentation..pdfKamal Acharya
The Division of Vaccine and Immunization is facing increasing difficulty monitoring vaccines and other commodities distribution once they have been distributed from the national stores. With the introduction of new vaccines, more challenges have been anticipated with this additions posing serious threat to the already over strained vaccine supply chain system in Kenya.
Saudi Arabia stands as a titan in the global energy landscape, renowned for its abundant oil and gas resources. It's the largest exporter of petroleum and holds some of the world's most significant reserves. Let's delve into the top 10 oil and gas projects shaping Saudi Arabia's energy future in 2024.
Forklift Classes Overview by Intella PartsIntella Parts
Discover the different forklift classes and their specific applications. Learn how to choose the right forklift for your needs to ensure safety, efficiency, and compliance in your operations.
For more technical information, visit our website https://intellaparts.com
Sachpazis:Terzaghi Bearing Capacity Estimation in simple terms with Calculati...Dr.Costas Sachpazis
Terzaghi's soil bearing capacity theory, developed by Karl Terzaghi, is a fundamental principle in geotechnical engineering used to determine the bearing capacity of shallow foundations. This theory provides a method to calculate the ultimate bearing capacity of soil, which is the maximum load per unit area that the soil can support without undergoing shear failure. The Calculation HTML Code included.
Immunizing Image Classifiers Against Localized Adversary Attacksgerogepatton
This paper addresses the vulnerability of deep learning models, particularly convolutional neural networks
(CNN)s, to adversarial attacks and presents a proactive training technique designed to counter them. We
introduce a novel volumization algorithm, which transforms 2D images into 3D volumetric representations.
When combined with 3D convolution and deep curriculum learning optimization (CLO), itsignificantly improves
the immunity of models against localized universal attacks by up to 40%. We evaluate our proposed approach
using contemporary CNN architectures and the modified Canadian Institute for Advanced Research (CIFAR-10
and CIFAR-100) and ImageNet Large Scale Visual Recognition Challenge (ILSVRC12) datasets, showcasing
accuracy improvements over previous techniques. The results indicate that the combination of the volumetric
input and curriculum learning holds significant promise for mitigating adversarial attacks without necessitating
adversary training.
Industrial Training at Shahjalal Fertilizer Company Limited (SFCL)MdTanvirMahtab2
This presentation is about the working procedure of Shahjalal Fertilizer Company Limited (SFCL). A Govt. owned Company of Bangladesh Chemical Industries Corporation under Ministry of Industries.
Final project report on grocery store management system..pdfKamal Acharya
In today’s fast-changing business environment, it’s extremely important to be able to respond to client needs in the most effective and timely manner. If your customers wish to see your business online and have instant access to your products or services.
Online Grocery Store is an e-commerce website, which retails various grocery products. This project allows viewing various products available enables registered users to purchase desired products instantly using Paytm, UPI payment processor (Instant Pay) and also can place order by using Cash on Delivery (Pay Later) option. This project provides an easy access to Administrators and Managers to view orders placed using Pay Later and Instant Pay options.
In order to develop an e-commerce website, a number of Technologies must be studied and understood. These include multi-tiered architecture, server and client-side scripting techniques, implementation technologies, programming language (such as PHP, HTML, CSS, JavaScript) and MySQL relational databases. This is a project with the objective to develop a basic website where a consumer is provided with a shopping cart website and also to know about the technologies used to develop such a website.
This document will discuss each of the underlying technologies to create and implement an e- commerce website.
COLLEGE BUS MANAGEMENT SYSTEM PROJECT REPORT.pdfKamal Acharya
The College Bus Management system is completely developed by Visual Basic .NET Version. The application is connect with most secured database language MS SQL Server. The application is develop by using best combination of front-end and back-end languages. The application is totally design like flat user interface. This flat user interface is more attractive user interface in 2017. The application is gives more important to the system functionality. The application is to manage the student’s details, driver’s details, bus details, bus route details, bus fees details and more. The application has only one unit for admin. The admin can manage the entire application. The admin can login into the application by using username and password of the admin. The application is develop for big and small colleges. It is more user friendly for non-computer person. Even they can easily learn how to manage the application within hours. The application is more secure by the admin. The system will give an effective output for the VB.Net and SQL Server given as input to the system. The compiled java program given as input to the system, after scanning the program will generate different reports. The application generates the report for users. The admin can view and download the report of the data. The application deliver the excel format reports. Because, excel formatted reports is very easy to understand the income and expense of the college bus. This application is mainly develop for windows operating system users. In 2017, 73% of people enterprises are using windows operating system. So the application will easily install for all the windows operating system users. The application-developed size is very low. The application consumes very low space in disk. Therefore, the user can allocate very minimum local disk space for this application.
TECHNICAL TRAINING MANUAL GENERAL FAMILIARIZATION COURSEDuvanRamosGarzon1
AIRCRAFT GENERAL
The Single Aisle is the most advanced family aircraft in service today, with fly-by-wire flight controls.
The A318, A319, A320 and A321 are twin-engine subsonic medium range aircraft.
The family offers a choice of engines
2. INTRODUCTI
ON
The major drawback of the vapour compression refrigeration
system is that it requires large volume of refrigerant vapour
which requires large mechanical power for its operation.
If some methods are used to reduce this volume before
compression, there would be considerable reduction in weight
of the system and power requirement for its operation.
Heat energy can be used instead of work for producing
refrigeration because it gives high COP of the system with
machine operated with supply of work energy.
3. The absorption system differs fundamentally from vapour
in the method of employed forcompression system only
compressing the refrigerant.
In the absorption system, the compressor is replaced by an
absorber, generator and a pump.
A French Scientist Ferdinand Cane
developed the first
absorption refrigeration machine in early 1860.
Nowadays, units are developed upto 1500 tons capacity.
The units which are generally used for
air conditioning purposes are available from 100 tons
capacity .
4. PRINCIPLE OF ABSORPTIN
SYSTEM
There is the peculiar property of some substances to have
affinity for another substances at some temperature and
pressure conditions and less affinity at another conditions.
This idea for the working principle of a vapour absorption
system was generated by Michael Faraday in 1824.
He knew that silver chloride (AgCl)m a white powder , had a
property of absorbing large amount of ammonia gas at the
normal temperature and pressure.
5.
6. Two chambers are combined with the help of a tube.
The white powder was kept inside the first chamber to which ammonia
gas was supplied and sealed.
The powder was heated up while other end was cooled
using circulating
water.
Liquid ammonia was obtained in the cool end of the apparatus. After
stopping heat, it was observed that, the liquid ammonia instead of sitting
there, started boiling( bubbles produced) and vapour was reabsorbed by
the white powder.
Upon touching the boiling end , it was astonished to find that the vessel
was very cold.
He repeated the experiments and cooling was observed again.
This led to invention of the intermittent Vapour
absorption system having solid as an absorber.
7. REFRIGERANT ABSORBER STATE OF
ABSORBER
AMMONIA WATER LIQUID
AMMONIA SODIUMTHIOCYNATE SOLID
AMMONIA LITHIUM NITRATE SOLID
AMMONIA CALCIUM CHLORIDE SOLID
AMMONIA ISOBUTANE SOLID
WATER LITHIUM BROMIDE SOLID
WATER LITHIUM CHLORIDE SOLID
METHYL
CHLORIDE
DIMETHYL ETHER OF TETRA
ETHYLENE GLYCOL
LIQUID
REFRIGERANT –ABSORBER PAIRS
11. SIMPLE VAPOR ABSORPTION REFRIGERATION
SYSTEM
@Point 1
-low temperature and low pressure
refrigerant vapour from evaporator at state 1
enters the absorber and is absorbed by solution
weak in refrigerant (state 8) .
The heat of absorption (Qa
) is rejected to an
external heat sink at T∞
.
12. SIMPLE VAPOR ABSORPTION REFRIGERATION
SYSTEM
@Point 2
-The solution, rich in refrigerant is pumped to
the generator pressure (Pg
) by the solution pump
(state 3). The pressurized solution gets heated up
sensibly as it flows through the solution heat
exchanger by extracting heat from hot solution
coming from generator (state 4).
13. SIMPLE VAPOR ABSORPTION REFRIGERATION
SYSTEM
@Point 5
-Heat is supplied to this solution from an
external heat source in the generator (Qg
at Tg
), as a
result refrigerant vapour is generated (absorbent
may also boil to give off vapour in case of ammonia-
water systems) at state 5.
This high-pressure refrigerant vapour condenses in
the condenser by rejecting heat of condensation to
the external heat sink (Qc
at T∞
) and leaves the
condenser as a high pressure liquid (state 9).
14. SIMPLE VAPOR ABSORPTION REFRIGERATION
SYSTEM
@Point 10
- the high pressure refrigerant liquid is
throttled in the expansion device to evaporator
pressure Pe
from where it enters the evaporator,
extracts heat from low temperature heat source (Qe
at Te
) and leaves the evaporator as vapour at state
1, completing a cycle.
15. SIMPLE VAPOR ABSORPTION REFRIGERATION
SYSTEM
@Point 6
- The hot solution that is weak in refrigerant
(state 6) leaves the generator at high temperature
and is cooled sensibly by rejecting heat to the
solution going to the generator in the solution heat
exchanger (state 7).
Then it is throttled to the evaporator pressure in
the throttle valve (state 8), from where it enters the
absorber to complete the cycle.
18. COP FOR IDEAL VAPOR ABSORPTION
REFRIGERATION SYSTEM
Absorption system requires a relatively large
amount of low-grade thermal energy at generator
temperature to generate refrigerant vapour from
the solution in generator. Thus while the energy
input is in the form of mechanical energy in
vapour compression refrigeration systems, it is
mainly in the form of thermal energy in case of
absorption systems.
19. COP FOR IDEAL VAPOR ABSORPTION
REFRIGERATION SYSTEM
The solution pump work is often negligible
compared to the generator heat input. Thus the
COPs for compression and absorption systems are
given by:
20. COP FOR IDEAL VAPOR ABSORPTION
REFRIGERATION SYSTEM
Thus absorption systems are advantageous where
a large quantity of low-grade thermal energy is
available freely at required temperature.
However, it will be seen that for the refrigeration
and heat rejection temperatures, the COP of
vapour compression refrigeration system will be
much higher than the COP of an absorption
system as a high grade mechanical energy is used
in the former, while a low-grade thermal energy is
used in the latter.
21. COP FOR IDEAL VAPOR ABSORPTION
REFRIGERATION SYSTEM
However, comparing these systems based on COPs
is not fully justified, as mechanical energy is more
expensive than thermal energy. Hence, sometimes
the second law (or exergetic) efficiency is used to
compare different refrigeration systems. It is seen
that the second law (or exergetic) efficiency of
absorption system is of the same order as that of a
compression system.
23. MAXIMUM COP FOR IDEAL VAPOR ABSORPTION
REFRIGERATION SYSTEM
From first law of thermodynamics,
Where
Qe
is the heat transferred to the absorption system
at evaporator temperature Te
,
Qg
is the heat transferred to the generator of the
absorption system at temperature Tg
,
Qa+c
is the heat transferred from the absorber and
condenser of the absorption system at
temperature To
and
Wp
is the work input to the solution pump.
24. MAXIMUM COP FOR IDEAL VAPOR ABSORPTION
REFRIGERATION SYSTEM
If we assume that heat rejection at the absorber
and condenser takes place at same external heat
sink temperature To
, then a vapour absorption
refrigeration system operates between three
temperature levels, Tg
, To
and Te
.
25. MAXIMUM COP FOR IDEAL VAPOR ABSORPTION
REFRIGERATION SYSTEM
The maximum possible COP of an ideal VARS
system is given by:
26. MAXIMUM COP FOR IDEAL VAPOR ABSORPTION
REFRIGERATION SYSTEM
Thus the ideal COP is only a function of operating
temperatures similar to Carnot system. It can be
seen from the above expression that the ideal COP
of VARS system is equal to the product of
efficiency of a Carnot heat engine operating
between Tg
and To
and COP of a Carnot
refrigeration system operating between To
and Te
,
27. MAXIMUM COP FOR IDEAL VAPOR ABSORPTION
REFRIGERATION SYSTEM
Thus an ideal vapour absorption refrigeration
system can be considered to be a combined system
consisting of a Carnot heat engine and a Carnot
refrigerator as shown in Fig.14.4. Thus the COP of
an ideal VARS increases as generator temperature
(Tg
) and evaporator temperature (Te
) increase and
heat rejection temperature (To
) decreases.
However, the COP of actual VARS will be much
less than that of an ideal VARS due to various
internal and external irreversibilities present in
actual systems.
28.
29. PRACTICAL VAPOR ABSORPTION REFRIGERATION
SYSTEM
A practical VARS has 3 additional parts :
ANALYSER
RECTIFIER
HEAT EXCHANGER
32. 1. Hydrogen enters the pipe with liquid ammonia (or
lithium bromide solution)
2. Ammonia and hydrogen enter the inner
compartment of the refrigerator. An increase in volume
causes a decrease in the partial pressure of the liquid
ammonia. The ammonia evaporates, requiring energy
to overcome the ΔHVap. The required energy is drawn
from the interior of the refrigerator, thus cooling it.
3. Ammonia and hydrogen return from the inner
compartment, ammonia returns to absorber and
dissolves in water. Hydrogen is free to rise upwards.
4. Ammonia gas condensation (passive cooling).
5. Hot ammonia (gas).
6. Heat insulation and distillation of ammonia gas
from water.
7. Heat source (electric).
8. Absorber vessel (water and ammonia solution).
37. VARS BASED ON H2O – LIBR PAIR
Vapour absorption refrigeration systems using
water-lithium bromide pair are extensively used
in large capacity air conditioning systems.
In these systems water is used as refrigerant and
a solution of lithium bromide in water is used as
absorbent.
Since water is used as refrigerant, using these
systems it is not possible to provide refrigeration
at sub-zero temperatures. Hence it is used only
in applications requiring refrigeration at
temperatures above 0o
C.
38. VARS BASED ON H2O – LIBR PAIR
Hence these systems are used for air conditioning
applications. The analysis of this system is
relatively easy as the vapour generated in the
generator is almost pure refrigerant (water),
unlike ammonia-water systems where both
ammonia and water vapour are generated in the
generator.
39.
40.
41.
42. STEADY FLOW ANALYSIS OF WATER-
LITHIUM BROMIDE SYSTEMS
A steady flow analysis of the system is carried out with
the following assumptions:
i. Steady state and steady flow
ii. Changes in potential and kinetic energies across
each component are negligible
iii. No pressure drops due to friction
iv. Only pure refrigerant boils in the generator.
The nomenclature followed is:
m= mass flow rate of refrigerant, kg/s
mss= mass flow rate of strong solution (rich in LiBr),
kg/s
mws= mass flow rate of weak solution (weak in LiBr),
kg/s
43. Circulation ratio (λ)
-defined as the ratio of
strong solution
flow rate to
refrigerant
flow rate.
It is given by:
λ = mss/m
44. @Condenser
m1 = m2 = m3
Qc = m(h1 – h2)
Pc = Psat (TC)
where TC is the
condenser
temperature
45. @Expansion valve (refrigerant):
m2 = m3 = m
h2 = h3
@Evaporator:
m3 = m4 = m
QE = m(h4 – h3)
PE = PSAT(TE)
where TE is the
evaporator
temperature
46. @Absorber
From total mass balance:
m + mss = mws
but mss = λm,
mws = (1+λ)m
QA=mh4+ λmh10
- (1+λ)mh5
47. @Solution pump
m5 = m6 = mws
Wp = mws(h6-h5)
=(1+λ)m(h6-h5)
Even though
the solution pump
work is small it is
still required in the
selection of
suitable pump.
48. @Generator
m7 = m8 +m1
Heat input to the
generator is given by:
QG=mh1+λmh8
-(1+λ)mh7
49. @Solution heat exchanger
m6 = m7 = mws
m8 = m9 = mss
heat transfer
rate in the solution
heat exchanger, Q
is given by:
QHX = (1+λ)m(h7-h6)
=λm(h8-h9)
51. ADVANTAGES OVER VAPOUR
COMPRESSION SYSTEM
As there is no moving parts in the entire system, the operation
is essentially quiet and subjected to a very little wear, so that
the maintenance cost is low.
The pump motor is quite small compared with the compressor
motor.
Vapour absorption system is used the thermal energy, they
can be used in places, where electric power is hard to obtain.
Absorption unit can be built in capacities well above 1000 tons
Space requirement is less.
54. SAMPLE PROBLEM IN SIMPLE VARS
9. The operating temperatures of a single stage
vapour absorption refrigeration system are:
generator: 90o
C; condenser and absorber: 40o
C;
evaporator: 0o
C. The system has a refrigeration
capacity of 100 kW and the heat input to the
system is 160 kW. The solution pump work is
negligible.
a) Find the COP of the system and the total heat
rejection rate from the system.
b) An inventor claims that by improving the
design of all the components of the system he could
reduce the heat input to the system to 80 kW while
keeping the refrigeration capacity and operating
temperatures same as before. Examine the validity
of the claim.