27/10/2009 1

ALICE-PHOS

ALICE-PHOS

Alexei.Kuryakin@cern.ch

PHOS Cooling status (1-27 Oct)Brief

History:28 Sep start cool down. Steps (by liquid) was:

+17, +5, -3, -10, -15, -20, -25, -30, -29.5°C.

2 interlocks happened and was fixed:– 1 Oct – alarm on ECV controller battery fail, fixed;– 19 Oct – alarm on low pump cover temperature threshold, fixed.

At the moment (27 Oct):Nominal PHOS stabilization temperature achieved.Temperature (by Pt100 sensors):

Cooling liquid (C6F14): -29.50 ± 0.06°C

PWO2: -25.00°C, PWO3: -24.40°C, PWO4: -25.02°C

FEE2: +15.41°C, FEE3: +16.31°C, FEE4: +10.16°C.

Humidity (by 3×PWO + 2×FEE sensors):PWO2: 42,46,23%, PWO3: 43,43,29%, PWO4: 64,38,26%

FEE2: 7,4%, FEE3: 12,16%, FEE4: 7,8%

Liquid level in receiver tank ~53 Liters.

27/10/2009 2

ALICE-PHOS

ALICE-PHOS

Alexei.Kuryakin@cern.ch

PHOS Cooling status (1-27 Oct) PHOS temperatures (overview)

Nominal stabilization temperature achieved 21 Oct

cooling liquid(C6F14)

FEE2 FEE3

FEE4

PWO2

PWO3PWO4Interlock 1 Oct.

Interlock 19 Oct.

27/10/2009 3

ALICE-PHOS

ALICE-PHOS

Alexei.Kuryakin@cern.ch

PHOS Cooling status (1-27 Oct) PHOS temperatures (details)

In constant FEE state ± 0.1°C PWO stability shown

cooling liquid(C6F14)

PWO2PWO3

PWO4

Stability of cooling liquid average (per control cycle)

temperature are: -29.50 ± 0.06°C

FEE switchon/off causetemperaturevariations

PWO3temperature0.5°C higher

then PWO2,PWO4 (why?)

Temperature difference between PWO and cooling liquid is

about 4.5°C

27/10/2009 4

ALICE-PHOS

ALICE-PHOS

Alexei.Kuryakin@cern.ch

PHOS Cooling status (1-27 Oct)Cooling liquid level ~53 L

Temperature effect + (possible) leak ~1 L/week (?)

+5°C

-3°C

-25°C

-10°C

-30°C-20°C

-15°C

Interlock 19 Oct by pump cover temperature

Interlock 1 Oct by ECV controller battery, +25°C

-5°C ~3 Litres of C6F14

filled 21 Oct

Now ~53.3 LitresNeed more time to eastimate leak

27/10/2009 5

ALICE-PHOS

ALICE-PHOS

Alexei.Kuryakin@cern.ch

PHOS Cooling status (1-27 Oct)PHOS-2 humidity

FEE2

PWO2

27/10/2009 6

ALICE-PHOS

ALICE-PHOS

Alexei.Kuryakin@cern.ch

PHOS Cooling status (1-27 Oct)PHOS-3 humidity

FEE3

PWO3

27/10/2009 7

ALICE-PHOS

ALICE-PHOS

Alexei.Kuryakin@cern.ch

PHOS Cooling status (1-27 Oct)PHOS-4 humidity

FEE4

PWO4

27/10/2009 8

ALICE-PHOS

ALICE-PHOS

Alexei.Kuryakin@cern.ch

PHOS Cooling status (1-27 Oct)Pump cover temperatures

Pump2

Pump1

Pumps works inround-robin order(8 hours per cycle)

to equalizeworking times

27/10/2009 9

ALICE-PHOS

ALICE-PHOS

Alexei.Kuryakin@cern.ch

PHOS Cooling status (1-27 Oct)Compressor cover temperatures

Comp.2

Compressors alsoworks in round-robin order (8hours per cycle)

to equalizeworking times

Comp.3

Comp.4

Comp.1

27/10/2009 10

ALICE-PHOS

ALICE-PHOS

Alexei.Kuryakin@cern.ch

PHOS Cooling System status (1-27 Oct) Concept scheme (just to remind)

Evaporator (suction header)

Condenser (discharge header)4 Compressors

Freon R404Areceiver

Water condenser for

freon cooling

HeatExchanger

R404A C6F14

ElectricControlValve

ECVcontroller

2 Pumps

Receivertank 65L

C6F14

Cooling serveralidcscom252

LAN2

DCS serveralidcscom072phs_topprojectPVSS

LAN1

DIM

4 compressors, 2 pumps, 3 heaters, 2 valves,Electric Control Valve + controller, fan,3 pressure + 14 temperature sensors, liquidlevel sensor, thermo/oil/pressure relays,funless industrial computer, 10×I-7000 RS-485remote data acquisition modules, 6×ELMB cards,15 humidity + 96 temperature sensors in PWO,FEE

PHOSControl unit (ADC, DIO etc)

RS-485

Feedbacktemperature

sensor

27/10/2009 11

ALICE-PHOS

ALICE-PHOS

Alexei.Kuryakin@cern.ch

PHOS Cooling System status (1-27 Oct) PHOS DCS servers scheme

PHOS cooling control - alidcscom252 (AliPhosCool program)PHOS cooling client - alidcscom074 (PVSS, phs_col project)PHOS cooling top GUI – alidcscom072 (PVSS, phs_top project)

27/10/2009 12

ALICE-PHOS

ALICE-PHOS

Alexei.Kuryakin@cern.ch

PHOS Cooling System status (1-27 Oct) Cooling control server: alidcscom252

Cooling plant works as DIM server under controlof AliPhosCool program designed in VNIIEF,Sarov.RS-485 and CAN devices uses for data taking & control.

Cooling serveralidcscom252Special funless

industrial computer,located insidecooling plant

27/10/2009 13

ALICE-PHOS

ALICE-PHOS

Alexei.Kuryakin@cern.ch

PHOS Cooling System status (1-27 Oct) Cooling top GUI server: alidcscom072

Cooling plant GUI works as DIM client under PVSS.It’s fully integrated into ALICE DCS structures.But (at the moment) shifter can only view cooling data.To control cooling, expert should login to alidcscom252.

27/10/2009 14

ALICE-PHOS

ALICE-PHOS

Alexei.Kuryakin@cern.ch

PHOS Cooling System status (1-27 Oct) Stabilization algorithm

PHOS cooling stabilization algorithm based on compressorswitch on/off by feedback temperature sensor. So liquidtemperature is not constant, but average temperature percontrol cycle is stable (±0.1°C).

27/10/2009 15

ALICE-PHOS

ALICE-PHOS

Alexei.Kuryakin@cern.ch

PHOS Cooling status (1-27 Oct)Stabilization: control parameters

Control parameters:Tstab – wanted stabilization temperature of cooling liquidDelta – temperature corridor to switch compressors on/offNbMin – minimal number of compressors (when T < Tstab-Delta)NbMax – maximal number of compressors (when T > Tstab+Delta)

Monitor parameters:Taver – achieved average (per control cycle) temperature of liquidCaver – achieved period (in minutes) of control cycleNaver – achieved average (per control cycle) number of compressors

Tstab°C

Delta°C

NbMin NbMaxTaver°C

Caverminutes

Naver

+17 1 0 1 17.18 ± 0.13 3.09 ± 1.19 0.31 ± 0.08

+5 1 0 1 5.01 ± 0.01 6.11 ± 0.05 0.45 ± 0.02

+3 1 0 1 2.99 ± 0.01 6.25 ± 0.04 0.51 ± 0.02

-3 1.5 0 2 -2.94 ± 0.17 6.71 ± 1.50 0.79 ± 0.06

-4 1.5 0 2 -3.97 ± 0.03 7.10 ± 0.19 0.82 ± 0.04

-10 1 0 2 -9.99 ± 0.03 2.24 ± 0.11 1.16 ± 0.04

-15 1 1 3 -14.94 ± 0.19 7.44 ± 5.65 1.69 ± 0.24

-20 1 1 3 -20.31 ± 0.02 5.32 ± 0.30 2.55 ± 0.02

-25 1 2 4 -25.21 ± 0.09 4.81 ± 0.82 3.43 ± 0.12

-29.5 0.3 3 4 -29.50 ± 0.06 4.64 ± 2.74 3.74 ± 0.13

-30 0.2 3 4 -29.97 ± 0.05 6.43 ± 3.53 3.85 ± 0.09

Main control parameter is Tstab.Delta, NbMin, NbMaxdepends on Tstab.Parameters chosen to achieve stable

periodic control cycle (when possible).

Large Caver “sigma” means control cycle instability

(large variations of period)

Table shows used parameter values

27/10/2009 16

ALICE-PHOS

ALICE-PHOS

Alexei.Kuryakin@cern.ch

PHOS Cooling status (1-27 Oct)Stabilization: power problem

As shown in table and picture, at -30°C we are working near maximum of compressor’s power (~94% of max. power).This cause some instability of control cycle (see pic.).Remind that we have another (more powerful) cooling machine in b.167. At the moment this machine is not ready for operation, so we should plan this item for the next year.

Control cycle period is not stable enough

27/10/2009 17

ALICE-PHOS

ALICE-PHOS

Alexei.Kuryakin@cern.ch

PHOS Cooling System status (1-27 Oct) Safety: Alarms and Interlocks

PHOS cooling plant have 3 outcome Interlocks:1. Hardware (normal opened relay) – signal in case of

cooling system power off or control computer hang2. Software (DIM service) – signal in case of alarms, i.e.

dangerous conditions (some parameter out of threshold)3. Network (DIM service) – shows that cooling server

(alidcscom252) still alive

Software alarm produce interlocks by 35 conditions.Interlock mean that cooling plant halted because it

could not continue safe operation.

Important note:Cooling system alarms protect cooling plant against

damage, but not PHOS PWO & FEE.PHOS protection is job for higher DCS level (PVSS,

phs_top project).

27/10/2009 18

ALICE-PHOS

ALICE-PHOS

Alexei.Kuryakin@cern.ch

PHOS Cooling System status (1-27 Oct) Safety: Alarms and Interlocks

Software alarms : 35 conditions

Each alarm conditionhave:1) Flag

(enable/disable)

2) Timeout(milliseconds)

3) Threshold(optional parameter)

Positive timeout produce temporary device blockingNegative timeout produce Interlock, i.e. fatal alarm and system HALT

Interlock requireshifter’s commandto Reset

27/10/2009 19

ALICE-PHOS

ALICE-PHOS

Alexei.Kuryakin@cern.ch

PHOS Cooling System status (1-27 Oct) Problems and discussions

1. Leak ~1 L per week in PHOS-4, ~8 month of work (without liquid filling). More liquid should be purchased next year (~60 liters ?).

2. Cooling system’s Control Parameters and Alarms tuning should be done after period of test operation (partly done).

3. It’s not quit clear how L3 magnetic field influent to temperature sensors in PWO. Should be tested.

4. Phs_top (PVSS) actions on cooling plant interlocks is still under discussion and should be modified (maybe).

5. Detail documentation (manuals) should be written for “cooling experts”.

6. For next year new cooling machine (more powerful) should be assembled and connected.