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 3rd , Send signal to stop Cond_pump_2
If current chiller is 1st , 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