תגית: PLC

   Schedule of System Operation – SSO

Turbine Air Inlet Cooling

This article is an elaborated example of a schedule of system operaton – sso we did for one of our clients. Of course the actual documents contain all the operational and alarm parameters  

                Scope

This Schedule of System Operation (SSO) covers the required technical data and operation logic regarding the components of Turbine Air Inlet Cooling system, according to the Smartlogic's requirements and the client specifications

              System General Description

 :Turbine Air Inlet Cooling system contains two cold liquid circuits

Primary – 4 chillers and their respective primary pumps

Secondary – 2 pumps for each turbine inlet air cooling coil, 2 pumps for Cogen1, 2 pumps for Cogen2, and 2 pumps for the electric generator cooling (one operating and the other in standby

                Applicable Documents

User Requirements Specification (URS) for Monitoring and Alarm System

Parameters List

            Operational Parameters List

                          Alarm Parameters List

                              Operation Logic

            :Start Conditions of Chiller

COND_SYS_RDY Signal is on
Relevant pumps are waiting for our commands, including their corresponding valves

OIL_PUMP_OK Signal is on

READY Signal from MCC (C-025/RD) is on

READY Signal from Chiller (JM-025/RD) is on

ZS (Freeze protector) Signal is off, not indicating alarm

           : Running Logic for Chiller

Start corresponding Reg_valve (condenser regulate valve) on 100% and wait until valve feedback indicating >= 95%

Delay REG_VALVE_DLY_SP – 10 second

:If number of operating chillers <= 2

Send signal to  Start_cond_pump_1 – Start one Condense Pump

:If number of operating chillers > 2

Send signal to  Start_cond_pump2 – Start Two Condense Pumps

Verify from via communication that relevant cond_pump has

Delay 20 seconds

Perform PID on PDIT using Reg_valve according to relevant PDT-081-4_SP DeltaP SP
(in manual and/or auto mode)

Start CHW_Pump, chilled water pump

Delay 30 second

Verify relevant FS (flow) Signal is on for 20 seconds

Start Chiller

           : Stop operation for each Chiller

Delay 2 minutes , safety in case user changed the operation order of chillers from HMI

Stop Chiller

Wait for signal off from motor MCC feedback

Delay 60 Sec

If current chiller is 3^rd , Send signal to stop Cond_pump_2

If current chiller is 1^st , Send signal to stop Cond_pump_1

Close Reg_valve, condenser regulate valve

Delay 30 Sec

Stop CHW_Pump, chilled water pump
Interlock: in any case, CHW_Pump will continue operating as long as the corresponding chiller is operating

            Consumers Pump activation

User can always choose primary/secondary pump

If demand cooling for cogen1/2 via .DI 20 for cogen 1, DI 21 for cogen 2

For first activation: Check TT-087 (supply water) is below SP +1

:Perform PID control with relevant Cogen-TT
For Cogen-1 TE-315-022, for Cogen-2 TE-316-093
according to TT_315_022_SP / TT_316_093_SP using cogen-1/2 primary pump

If PID control loop reaches >= START_HZ_SP activate secondary pump and Continue PID control loop with both primary and secondary pumps

If both primary and secondary pumps at work and PID control loop reaches <= STOP_HZ_SP deactivate secondary pump and Continue PID control loop with primary pump only

If outlet air from cogen 1 or 2 below setpoint -2°C and the pump speed in minimum for 3 minute, stop the cogen pump

When the outlet air is above set point +1°C for 1 minute start the pump

*Generator equipment is not connected to the our PLC

           :Consumers Pumps activation for generator

If number of operating chillers <= 2 then activate first pump

If number of operating chillers > 2 then activate second pump

Stop pumps using reverse order

            :Temperature control for generator valves

Perform PID control with TT-090 according to SP using TV-088, If 316-J-21A operates

Perform PID control with TT-090 according to SP using TV-089, If 316-J-21B operate

           :Start Conditions of Chiller sequence

Demand Cooling at least from one of Cogen-1 / Cogen-2 / Generator. slot 4 DI-19-20-21

            :Chiller sequence run-up

Start first chiller according ‎6

The chilled water pump in the first chiller will start all the time even if we are not receive "chiller ready to start", we do need to receive "MCC ready" and do not receive "chiller shut down" . this function are necessary when the chiller stop in" low water temperature"

Delay Run-up Start_Chiller_DelaySP delay – 10 minutes

According to demand, start next chiller

:Perform sequence control using the maximum calculated value from
:{Flow measurement} calculation and {Temp measurement} calculation

:By flow measurement

Chiller #2 operates when total flow is > CH2_FLOW_SP + CH_FLOW_OFFSET_ SP

Chiller #3 operates when total flow is > CH3_FLOW_SP + CH_FLOW_OFFSET_ SP

Chiller #4 operates when total flow is > CH4_FLOW_SP + CH_FLOW_OFFSET_ SP

Chiller #2 stops when total flow is <= CH2_FLOW_SP – CH_FLOW_OFFSET_ SP

Chiller #3 stops when total flow is <= CH3_FLOW_SP – CH_FLOW_OFFSET_ SP

Chiller #4 stops when total flow is <= CH4_FLOW_SP – CH_FLOW_OFFSET_ SP

Total flow = FM1 + FM2 + GenFM

Here are some examples of the PLCs used by Smartlogic: 6XV1830-0EH10, 6ES7131-4BF00*0AA0, 6ES7193-4CA40-0AA0, 6ES7134-4GD00-0AB0, 6ES7193-4CA40-0AA0, 6ES7138-4CA01-0AA0, 6ES7193-4CC20-0AA0, 6ES7590-1AB60-0AA0, 6ES7511-1AK00-0AB0, 6ES7954-8LP01-0AA0, 6ES7155-6AU00-0BN0, 1746-NO4V, 1769-L16ER-BB1B