This document describes automating the break generator of an expansion turbine used in an air separation unit (ASU) plant. The existing relay-based logic system was causing spurious trips, hampering production. The project aimed to improve performance by implementing a new PLC-based automation system for continuous monitoring and improved reliability. The document discusses the expansion turbine process parameters, startup procedure, PLC advantages like eliminating spurious trips, and input-output configuration. Upon completion, the PLC automation was found to improve performance by minimizing breakdowns and ensuring safe operation.

1. AUTOMATION OF BREAK GENERATOR
Presented by
K.JANAKI
K.L.SUSHMA PRIYA
K.PRASAD
B.SANTHAN BHARDWAJ

2. CONTENTS
1.Aim of the project
2.Description of expansion turbine
3.Description of ASP
4.GEFANUC PLC system
a) advantages
b)disadvantages
5.Input output lists
6.Conclusion

3. AIM OF THE PROJECT
To improve the performance of “EXPANSION TURBINE OF ASU
- 1” and to provide necessary automation with latest Micro-
Processor based PLC logic system to avoid spurious trips.
Existing system is relay logic system. It is
always giving spurious trips and hampering production. With
the newly implemented PLC based system, we are able to
give continuous monitoring of all process parameters from
CCP DESKTOP monitor, historical trends, improved accuracy,
reliability and ensuring safe & continuous running of the
expansion turbine

4. DESCRIPTION OF EXPANSION
TURBINE
•A part of the air is taken at an intermediate point of the
exchangers and sent to a Centrifugal Expansion turbine
equipped with a Break Generator to provide the necessary
refrigeration to make-up the thermal losses of the cold box.
PROCESS PARAMETERS
Air flow (max.) : 37,500 Nm3/hr
Inlet pressure : 6.6 kg/cm2 abs
Outlet pressure : 1.45 kg/cm2 abs
Inlet temperature : (-) 135 ºC
Outlet temperature : (-) 178 ºc
Power : 550 KW
Model : ETG 360 NS
Constructor : ATLAS COPCO

5. TURBINE CHECK LIST
1.Oil level shown on oil gauge glass.
2.Thawing gas valves closed.
3.Nozzle blades closed.
4.Quick-close shutoff valve closed.
5.Temperature of turbine bearings .If temperature of either
bearing is less than +15 deg. C, bearings must be warmed by
turning on lubricating oil supply. Turbine outlet valve must be
closed. If bearing temperature cannot be raised by circulating
lubricating oil, turbine must be heated with thawing gas.
Oil filter clean and in circuit.
6.Adjust the stroke of nozzle control valve.

6. TURBINE START UP PROCEDURE
1.Turn on sealing gas supply.
2. Switch on control power supply for instruments and
controls.
3.Electrical auxiliary oil Pump starts automatically.
Turn on cooling water supply for oil cooler.
4.Open turbine outlet valve.
5.Open turbine inlet valve.
6.Open quick-close shutoff valve.

7. 7. Open up nozzle valve until operating speed level is
attained and generator cuts automatically.
8.Keep check on bearings temperatures, gap pressure
and satisfactory running of complete unit during start-up.
9.Switch off auxiliary oil pump by switch “oil pump off”.
10. After generator has cut in, load turbine by opening up
nozzle blades as far as required for given operating conditions.
11.During start-up briefly open drain and instrument lines
to vent them, re-closing afterwards.

8. DESCRIPTION OF ASP
Air Composition:-
Air is mainly a mixture of two gases:
Oxygen and Nitrogen in the following percentages.
*1/5th Oxygen, namely 20.96%.
*4/5th nitrogen, namely 78.11%.
Air also contains other components such as the five rare
gases, which are found in a constant percentage by volume.
Argon (Ar) – 0.93%
Neon (Ne) – 0.0015%
Helium (He) – 0.0005%
Krypton (Kr) – 0.0001%
Xenon (Xe) – 0.000008%

9. Some other components are also present in variable
quantities such as:
*Water vapor (H2O)
*Carbon dioxide (CO2 about 0.03%)
*Hydro carbons, Acetylene (C2H2)
*Ozone (O3)

10. SEPARATION OF AIR COMPONENTS
Air components are separated by means of liquid distillation
columns, in distillation column.
A thorough separation of air cannot be made by means of a
single rectification column:
1. The first one is the high pressure column separating
the process air into liquid nitrogen and oxygen rich liquid (40%
oxygen).
2. The second one is the low pressure column which is
used for final separation into pure nitrogen and oxygen.

11. AIR PURIFICATION
Air contains some water, carbon dioxide, hydrocarbons
and oil if it is compressed by means of lubricated equipment.
These components must be removed because water
and carbon dioxide when cooled to low temperatures may form
a deposit in the pipe work and result in subsequent plugging.
Acetylene and oil are also dangerous and may cause explosion
when they come into contact with liquid oxygen.
Heavier hydrocarbons are removed during cooling. It
should be noted that hydrocarbons may be removed when in
liquid state.

12. PROCESS DESCRIPTION
Air is sucked through air pulse filter which removes
the dust particles, then it goes through the inlet guide vane and
compressed in four stages.
. After first stage compression, the compressed air goes to
the first water inlet cooler and then to the second stage suction.
. From second stage discharge it goes to second cooler
and then to third stage suction.
. From third stage discharge it goes to third inter cooler and then
to fourth stage suction

13. .From fourth state discharge it goes to after cooler.
Discharge pressure after first, second, third and fourth stages are
0.75, 2.0, 3.8, 6.4 Kg/Cm2 respectively.
Suction pipe gas temperature of first stage to fourth
stage is 40 to 45 deg c. Discharge gas temperature at fourth stage
is 90 to 105 deg c.
To protect the machine from surges it has been
provided with anti-surge valve (ASV).When there is a sudden
increase of discharge pressure or decrease of discharge flow
through the compressor, the machine goes to an unstable region
called surge.

14. INTRODUCTION TO PLC’S
The break generator is equipped with pressure gauges,
temp Indicators, pressure switches, speed measurement &
vibration measurement systems and safety devices. At present all
safety interlocks are based on relay logic system.
In this proposed automation project the relay logic
system is converted into PLC based logic system.

15. PLC’S
The Series 90-30 PLC’S are members of the GE
Fanuc Series 90™ family of Programmable Logic Controllers
(PLC’S).
They are easy to install and configure, offer
advanced programming features, and are compatible with the
Series 90-70 PLC’S.
Two Windows-based configuration/programming
packages are available for Series 90-30 PLC’S. VersaPro
software supports all Series 90-30 CPUs.

16. . The software structure for the 341 and lower Series
90-30 PLC’S uses an architecture that manages memory and
execution priority in the 80188 microprocessor.
The 35x and 36x series of Series 90-30 PLC’S use
an 80386EX microprocessor
This operation supports both program execution and
basic housekeeping tasks such as diagnostic routines,
input/output scanners, and alarm processing.
The system software also contains routines to communicate
with the programmer.

17. The Series 90-30 Genius Bus Controller (catalog number
IC693BEM331) is used to interface a Genius I/O serial bus to a
Series 90-30 PLC. The GBC receives and transmits control data
of up to 128 bytes for up to 31 devices on the Genius bus.
A Genius bus may serve:
Genius blocks, which provide interface to a broad
range of discrete, analog, and special-purpose field devices.
Genius blocks are self-contained modules with advanced
diagnostics capabilities and many software-configurable features.

18. Remote Drops, Series 90-70 I/O racks that are interfaced to
the bus via Remote I/O Scanner Modules. Each remote drop can
include any mix of discrete and analog I/O modules, providing up
to 128 bytes of input data and 128 bytes of output data.
Hand-held Monitor, which can be used as a portable
device or permanently mounted. A HHM provides a convenient
operator interface for block setup, data monitoring, and
diagnostics.
Multiple hosts, for communications using datagram’s and
Global Data.

19. ADVANTAGES:
By replacing the analog systems with latest microprocessor
based Control systems the advantages are
1.Spurious indications will be eliminated.
2.Reliability will be ensured.
3.Production delays will be avoided.
4.Accuracy will be improved.
5.Events will be monitored.
6.Trip analysis becomes easier.
7.Historical trends will be obtained.
8.Maintenance cost will be reduced.
9.Spurious indications will be eliminated.
10.Reliability will be ensured.

20. 11.Production delays will be avoided.
12.Accuracy will be improved.
13.Events will be monitored.
14.Trip analysis becomes easier.
15.Historical trends will be obtained.
16.Maintenance cost will be reduced.

21. DISADVANTAGES:
1.All interlocks are used change over series contacts. So this is
very difficult to trace out the abnormalities in the process.
2.All the contacts are taking from the field switches.
3.Control panel and field switches are mounted on the body of
equipment. So during running condition switches are malfunctioning
due to vibration.
4.Spares are too costly.
5. Problem analysis and troubleshooting takes lot of time and
causing production delays.
6.All interlocks are used change over series contacts. So this is
very difficult to trace out the abnormalities in the process.

22. 7.All the contacts are taking from the field switches.
8.Control panel and field switches are mounted on the body
of equipment. So during running condition switches are
malfunctioning due to vibration.
9.Spares are too costly.
10.Problem analysis and troubleshooting takes lot of time
and causing production delays.

23. INPUT-OUTPUT PORTS
32 Point Discrete Input Module
Power Sources: The module receives power from the Field Processor to r
run its own 5-volt logic. An external 24VDC supply is needed to power the
input devices.
LEDs: Individual LEDs (logic side), visible through the transparent portion
of the module top, indicate the on/off status of each input. The PWR LED is
on when field and backplane power is present.
Host Interface: Intelligent processing for this module is performed by the
Bus Interface Unit or elsewhere in the system. This includes configuring
features such as input defaults and fault reporting. The module has 16 bits
(two bytes) of discrete input data. A Bus Interface Unit is required to provide
this input data to the host and/or local processor.

24. Module Operation: A network of resistors and capacitors establishes
input thresholds and provides input filtering. Opt isolators provide isolation
between the field inputs and the module's logic components. Data from all 16
inputs is placed into a data buffer.
32 Point Discrete Output Module
Power Sources: Power for the module itself comes from the power
supply in the Bus Interface Unit. An external source of DC power must be
provided for the switches that power the loads.
LEDs: Individual green LEDs (logic side) indicate the on/off status of
each output. The green LEDs remain off when user power is not present,
regardless of the state of the outputs. Individual yellow LEDs show the fault
status of each output. The green PWR LED is on when field and backplane
power are present.

25. Host Interface: Intelligent processing for this module is performed
by the Bus Interface Unit or elsewhere in the system. This includes
configuring features such as output default and fault reporting. The module
has 8 bits (one byte) of discrete output data. A Bus Interface Unit is required
to obtain this output data from the host and/or local processor.
Module Operation: After checking the Board ID, the Bus Interface
Unit sends output data to the module in serial format. During transmission,
the module automatically loops this data back to the Bus Interface Unit for
verification. Serial to parallel converters convert this data into the parallel
format needed by the module. Opto-isolators isolate the module's logic
components from field outputs. Power from the external power supply is
used to drive the FETs that source current to the loads.

26. CONCLUSION
After completion of the “AUTOMATION OF EXPANSION TURBINE
OF ASU – 1” the performance of the break generator is found to be improved.
Now the operation people are easily able to run the machine without
spurious breakdowns. In that context Instrumentation is playing major role in
early alarming and minimizing the breakdown of the equipment and ensuring
the safety of man / machine in very higher manner.
As this modification has been found successful in improving the safety
and minimizing the breakdowns, it is planned to implement the same to the
other units.
Hence it may be concluded that the modification is accurate, reliable,
trouble free and easily monitor.

27. THANK YOU

28. ANY QUARIES
?