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Functional Analysis and Control System for the Thermosiphon Chiller. Lukasz Zwalinski PH/DT /PO - Cooling. Introduction. Cascade refrigeration system with R23 as low temperature refrigerant and R404a as high temperature refrigerant. C6F14 brine circuit
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Functional Analysis and Control System for the Thermosiphon Chiller Lukasz Zwalinski PH/DT/PO - Cooling
Introduction Cascade refrigeration systemwith R23 as low temperature refrigerant and R404a as high temperature refrigerant C6F14 brine circuit Normal operation -64.93C to -70.25C Warm operation -14.85C to -20.81C liquid tank Normal operation evap. Cascade condenser R404a Water condenser R23 Surface USA15 cavern Warm operation evap. Air condenser • Main control actions for R23 circuit: • Flow control threw normal operation evap. => to ensure SH vapour condition • Compressor speed control => to mach required load • Hot gas injection control => if required capacity is less then capacity of the compressor • Economizer control => high pressure liquid refrigerant sub cooling • Main control actions for R404 circuit: • Flow control threw cascade condenser => to ensure SH vapour condition (Normal operation) • Compressor speed control => to mach required load • Hot gas injection control => if required capacity is less then capacity of the compressor (Warm operation) • Economizer control => high pressure liquid refrigerant sub cooling (Normal operation) • Air cooled condenser fan control in case of water failure UX15 cavern ATLAS ID Detector Thermosiphon workshop §5 20th October 2011 L.Zwalinski – PH/DT/PO
Introduction • Schneider Premium PLC based control system • UNICOS framework • System size (I/O number) • Chiller Brine + Water (Stephane’s talk) • EN-CV-DC hardware standard • Detector control system integration: same solution as already introduced by EN-ICE for Detector Gas Group Thermosiphon workshop §5 20th October 2011 L.Zwalinski – PH/DT/PO
Control system architecture V1 Thermosiphon workshop §5 20th October 2011 L.Zwalinski – PH/DT/PO
Control system architecture V2 Thermosiphon workshop §5 20th October 2011 L.Zwalinski – PH/DT/PO
Split of responsibilities Thermosiphon workshop §5 20th October 2011 L.Zwalinski – PH/DT/PO
Status Thermosiphon workshop §5 20th October 2011 L.Zwalinski – PH/DT/PO
Functional analysis organization • In accordance with EN-ICE template functional analysis contains: • General process description • Process decomposition • UNIT A • 3.1 UNITA controlled devices description: type + parameters • 3.2 Operational states description • Definition • Transition condition • Logical sequences • Sub unit and actuators logic • 3.3 User command definition • 3.4 Computed variables • 3.5 UNIT / PCO Alarms • Hardware • Software • 3.6 Actuator alarms • Hardware • Software • 3.7 Actuator alarms parameters – recipes parameters • 3.8 Limiting conditions • 4. UNIT B … EDMS1165941 Thermosiphon workshop §5 20th October 2011 L.Zwalinski – PH/DT/PO
Process decomposition Chiller System Chiller 1 Chiller 2 Brine Water R404 R23 … To be defined To be defined EV53003 EV53007 Has to be defined in next 2 weeks maximum Economizer High temperature Economizer Low Temperature CV59235 CV59326 CV59330 CV59331 CV59332 CV59333 CV59318 CV59314 Warm Operation Evaporator Normal Evaporation Evaporator CV59240 EV59246 Cascade Condenser CV59232 CV59233 COMP59112 CV59301 CV59302 GT59364 F59505A F59505B F59505C F59505D Air Cooled Condenser COMP59502 CV59201 CV59202 CV59213 GT59263 Thermosiphon workshop §5 20th October 2011 L.Zwalinski – PH/DT/PO
P&ID vs process decomposition Air Cooled Condenser Economizer HT Economizer LT CascadeCondenser CV59235 Normal operation evaporator Warm operation evaporator R404 R23 Thermosiphon workshop §5 20th October 2011 L.Zwalinski – PH/DT/PO
Chiller 1 – Option modes and operation states • Option modes: • MAINTANACE: In this state, all equipment is stopped and there is no way to re-activate actuators from the program. All interlocks related to this unit are disabled. • OPERATION: nominal state in which Chiller is operated States: [0] Stopped: Both compressors are switched off all outputs are off except either EV53003DO or EV53007DO [1] Available for Warm Operation (WCC): The R404a compressor is not running, but is available to start, EV-53003 is confirmed open,EV-53007 is closed.The chiller is using the Water Cooled Condenser and the manual changeover valves have been set for this condenser. A C6F14 pump is confirmed as running. [2] Available for Warm Operation (ACC): The R404a compressor is not running, but is available to start. EV-53003 is confirmed open, EV-53007 is closed.The chiller is using the Air Cooled Condenser and the manual changeover valves have been set for this condenser. Condenser fans are healthy and switched to auto. A C6F14 pump is confirmed as running. [3] Available for Normal Operation: Both compressors are available to start. A C6F14 pump is confirmed as running and either EV-53003 or EV-53007 is open. [4] Warm Operation with Air Cooled Condenser ACC: The R404a compressor is running. EV-53003 is open ,EV-53007 is closed. The R23 compressor is not required, so its status is ignored. Air Cooled condenser is running. [5] Normal Operation: Both compressors are running. EV-53003 is closed, EV-53007 is open. [6] Warm Operation with Water Cooled Condenser WCC: The R404a compressor is running. EV-53003 is open, EV-53007 is closed.The R23 compressor is not required, so its status is ignored. Water Cooled Condenser is running. Thermosiphon workshop §5 20th October 2011 L.Zwalinski – PH/DT/PO
Chiller 1 – Transition conditions • T0 = Transition from any state to STOP • A C6F14 pump running = 0 • EV-53003 AND EV-53007 = closed • EMSDI = 0 • PSU1DI AND PSU2DI = 0 • The R404a compressor {COMP-59502} is tripped • Chiller.RunOrder falling edge • T1 = Transition from STOP to Available Air Cooled Condenser • A C6F14 pump must be confirmed as running • Either EV-53003 or EV-53007 must be open • Master Emergency Stop healthy [EMSDI = 1] • Either PSU1 or PSU2 healthy [PSU1DI = 1 or PSU2DI = 1] • The R404a compressor is available or running • The manual changeover valves have been set for air cooled condenser operation. • At least three of the four air cooled condenser fans {F-59506A – F-59506D} • are healthy [F59506A_TDI - F59506D_TDI = 1] and • switched to Auto [F59506A_A - F59506D_A = 1] • T2 = Transition from STOP to Available Water Cooled Condenser: • A C6F14 pump must be confirmed as running • Either EV-53003 or EV-53007 must be open • Master Emergency Stop healthy [EMSDI = 1] • Either PSU1 or PSU2 healthy [PSU1DI = 1 or PSU2DI = 1] • The R404a compressor is available or running • The manual changeover valves have been set for water cooled condenser operation. • T3 = Transition from STOP to Available Normal Operation: • A C6F14 pump must be confirmed as running • Either EV-53003 or EV-53007 must be open • Master Emergency Stop healthy [EMSDI = 1] • Either PSU1 or PSU2 healthy [PSU1DI = 1 or PSU2DI = 1] • The R404a compressor is available or running • The R23 compressor is available or running • The manual changeover valves have been set for water cooled condenser operation. T4 = Transition from Normal Operation to Warm Operation: • Whilst running in Normal Operation, • The R23 compressor has either been commanded off by the operator, or switched off at the compressor starter panel [R23 Compressor AUTODI = 0], or has tripped, or is not available, AND the C6F14 brine temperature TT53101< -21.0oC. T5 = Transition from Warm Operation Water Cooled Condenser to Normal Operation: • R23 compressor unit is Available –AND • Manual Operator transition request from Warm Operation to Normal Operation Thermosiphon workshop §5 20th October 2011 L.Zwalinski – PH/DT/PO
R404 - compressor PCO operation states and transitions T0 = R404.RunOrder falling edge OR the switch on the compressor starter control panel (AUTODI = 0, OFFDI = 1 OffSt). T1 = ‘Starts per Hour’ timer is running OR Stop to Start timer is running T2 = ‘Starts per Hour’ timer is NOT running AND ‘Stop to Start’ timer is NOT running AND starter control panel switch is in the ‘ON’ position (AUTODI = 1, OFFDI = 0 OnSt) AND (EV-53007 or EV-53003 is open) AND C6F14 Pump running. T3 = Chiller start command = Chiller.RunOrder T4 = PT-59207 {R404a Compressor Discharge Pressure} <11.77 bara AND Economiser is switched off (NOT EHT.RunOrder) [0] Tripped: A ‘Full Stop Interlock’ has been implemented. The compressor is not running; one or more of the compressor operating parameters has reached a software trip threshold and stopped the compressor, or a hard wired protection device has stopped the compressor. [1] Stopped: The compressor is not running, it is not tripped. The compressor has been commanded to stop either by the operator or by the switch on the compressor starter control panel (AUTODI = 0, OFFDI = 1). [2] Waiting: The compressor is not running. It is not tripped. The starts per hour timer is running, or (EV-53007 and EV-53003 is not open), or C6F14 Pump not running. [3] Available: The compressor is not running, it is not tripped, it is not waiting, the starter control panel switch is in the ‘ON’ position (AUTODI = 1 OFFDI = 0). The compressor is waiting for a command to start [4] Running Auto: The compressor has been selected to ‘Auto’ on the local HMI and has been commanded to start and is running normally within the designed operating envelope and can vary its speed according to the R404a Compressor Speed Controller. [5] Running Manual: The compressor has been selected to ‘Manual’ on the local HMI and has been commanded to start by the manual ‘soft key’ start button on the HMI and can vary its speed according to the local ‘soft keys’ Manual Speed Increase & Manual Speed Decrease. [6] Running non economised: The compressor has been commanded to start and is running normally within the designed operating envelope and can vary its speed according to the R404a Compressor Speed Controller if selected to auto, or by the local ‘soft’ buttons on the HMI if selected to manual, but PT-59207 {R404a Compressor Discharge Pressure} <11.77 bara and the economiser is switched off Thermosiphon workshop §5 20th October 2011 L.Zwalinski – PH/DT/PO
Summary logic description table example Thermosiphon workshop §5 20th October 2011 L.Zwalinski – PH/DT/PO
Alarm parameters and recipes parameters Thermosiphon workshop §5 20th October 2011 L.Zwalinski – PH/DT/PO
Computed variables • Description: • Discharge Temperature (Saturated)(K) (Tsat) is calculated from this equation: • Tsat = A + (B x (LnP)) + (C x ((LnP)^2)) + (D x ((LnP)^3)) Discharge Superheat = Discharge Temperature (Actual)(K) – Discharge Temperature (Saturated)(K) • Range <-35.0,60.0> • Dead band 0.085K • Tsat is available and archived in PVSS Where A = 226.9570901 B = 20.82789774 C = 2.485671782 D = 0.208949075 P = PT-59207 {R404a Compressor Discharge Pressure} (bara) Tsat = Tsat59207 Then: R404-DSH = TT-59211 + 273.15 - Tsat Thermosiphon workshop §5 20th October 2011 L.Zwalinski – PH/DT/PO
Summary and what’s next? Chiller Functional Analysis and I/O List accepted on 12.10.2011 Hardware Ethernet IP tests in progress. In 2 weeks time I’ll start preparation of UNICOS object list Thermosiphon workshop §5 20th October 2011 L.Zwalinski – PH/DT/PO