AUTOMATION OF BREAK GENERATOR Presented by K.JANAKI K.L.SUSHMA PRIYA K.PRASAD B.SANTHAN BHARDWAJ
CONTENTS1.Aim of the project2.Description of expansion turbine3.Description of ASP4.GEFANUC PLC system a) advantages b)disadvantages 5.Input output lists 6.Conclusion
AIM OF THE PROJECTTo 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
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 necessaryrefrigeration 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
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 eitherbearing is less than +15 deg. C, bearings must be warmed byturning on lubricating oil supply. Turbine outlet valve must beclosed. If bearing temperature cannot be raised by circulatinglubricating oil, turbine must be heated with thawing gas. Oil filter clean and in circuit. 6.Adjust the stroke of nozzle control valve.
TURBINE START UP PROCEDURE 1.Turn on sealing gas supply. 2. Switch on control power supply for instruments andcontrols. 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. 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 upnozzle 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.
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 raregases, 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%
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)
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 separatingthe 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.
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 waterand 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.
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
.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 fourthstage 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.
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.
PLC’S The Series 90-30 PLC’S are members of the GEFanuc Series 90™ family of Programmable Logic Controllers (PLC’S). They are easy to install and configure, offeradvanced 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.
. 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.
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 advanceddiagnostics capabilities and many software-configurable features.
Remote Drops, Series 90-70 I/O racks that are interfaced to the bus via Remote I/O Scanner Modules. Each remote drop caninclude 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.
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.
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.
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 ofequipment. 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.
7.All the contacts are taking from the field switches. 8.Control panel and field switches are mounted on the bodyof 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.
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.
Module Operation: A network of resistors and capacitors establishes input thresholds and provides input filtering. Opt isolators provide isolationbetween the field inputs and the modules 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.
Host Interface: Intelligent processing for this module is performed by the Bus Interface Unit or elsewhere in the system. This includesconfiguring features such as output default and fault reporting. The modulehas 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 InterfaceUnit 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 modules logic components from field outputs. Power from the external power supply is used to drive the FETs that source current to the loads.
CONCLUSION After completion of the “AUTOMATION OF EXPANSION TURBINEOF ASU – 1” the performance of the break generator is found to be improved. Now the operation people are easily able to run the machine withoutspurious breakdowns. In that context Instrumentation is playing major role inearly 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.