1

CMS FPIX CoolingSystem Studies

Joe Howell, Fermilab

for the FPIX Upgrade Mechanical Working Group

CMS Upgrade Workshop

April 27, 2010

22

Outline

FPIX C02 Cooling CMS Upgrade Workshop April 27, 2010

• CO2 system

• System Design

• System Elements

• Status

• Half-cylinder cooling loops design and testing

3FPIX C02 Cooling CMS Upgrade Workshop April 27, 2010

C02 System Design Parameters

• Deliver saturated or slightly sub-cooled CO2 to detector

• Ability to handle 1-4 bar detector pressure drops

• Capacity to handle up to 5 kW heat load

• Ability to provide liquid CO2 at -30 °C to +15 °C

• CO2 quality at detector outlet of 25%, maximum

• CO2 side, design pressure of 82 bar (closed loop system will retain all CO2 at room temperature)

CMS Upgrade Workshop April 27, 2010 4FPIX C02 Cooling

C02 System Heat and Mass Balance Model

353 g/s

4.1 bar

A heat and mass balance EXCEL model was built based on C02 properties and the vendor supplied pump characteristics for the Warrender turbine pump.

18.7 bar

0.44 L/s

452 g/s

98 g/s.09 L/s

.34 L/s

CMS Upgrade Workshop April 27, 2010 5FPIX C02 Cooling

System Elements

• CO2 Pump• Passive Phase Separator (returns a portion of liquid)

• C02 Filter Dryer (absorb water to prevent ice and carbonic acid)

• CO2 Flow Control (pump speed control with flow instrumentation)

• Pressure (Temperature) Controlled• CO2 Condenser• Electric CO2 Tank Heater• Three Commercial Refrigeration Units• Pressure, Temperature and Flow Instrumentation

CMS Upgrade Workshop April 27, 2010 6FPIX C02 Cooling

C02 System Piping & Instrumentation Diagram

Refrigeration Units

Pump

Storage tank with condenser coils and heaters

Phase Separator

CMS Upgrade Workshop April 27, 2010 7FPIX C02 Cooling

Some Major System ElementsWarrender WMDAT6-2SM with a 3 Hp motor

610 mm

1524 mm

Storage Tank

Commercial R404A Refrigeration Unit

CMS Upgrade Workshop April 27, 2010 8FPIX C02 Cooling

Refrigeration Control

0.00

1.00

2.00

3.00

4.00

5.00

6.00

7.00

8.00

9.00

10.00

kW Load (kW)

Refrig (kW)

HTR (kW)STEP kW

0 - - - 0.001 1 - - 1.382 - 1 - 2.403 1 1 - 3.784 - - 1 4.265 1 - 1 5.646 - 1 1 6.667 1 1 1 8.04

units to run

UNIT kWU-1 1.38U-2 2.40U-3 4.26

• 3 Commercial refrigeration units (on/off style)• Sized and operated in combination to provide 0 to 8 kW of cooling• Electric heater used to trim to the final cooling requirement

CMS Upgrade Workshop April 27, 2010 9FPIX C02 Cooling

Preliminary What-if ? Analysis for Major Components

Sample

CMS Upgrade Workshop April 27, 2010 10FPIX C02 Cooling

C02 System Design and Construction Status

System Element Status

Pump Identified, procurement process started

CO2 CondenserVendor quotes received, procurement to start soon

Electric HeatersWorking with vendors for cost effective option to meet high pressure requirement

Storage Tank VesselIn design, fine tuning to match details of condenser and heater

Refrigeration units Specified, awaiting vendor quote

FilterAdapting a commercial C02 filter for use in a custom high pressure housing

Expected date for operational system, Fall 2010

CMS Upgrade Workshop April 27, 2010 11

HD2 I-O

FPIX C02 Cooling

Cooling Loops in Half-cylinder

FPIX CoolingLoop

Heat Load from

modules(t=0)[W]*

Heat Loadfrom

DC-DC converters &

port-cards[W]

Total Heat

Load on Cooling

Loop[W]

Length of cooling loop on half-ringOD 1.6 mmID 1.4 mm

[mm]

Length of radial legs of cooling loopOD= 1.6 mmID= 1.4 mm

[mm]

Length of 1st longitudinal legs of cooling loopOD = 1.6 mmID = 1.4 mm

[mm]

Length of 2nd longitudinal legs of cooling loopOD = 2.0 mmID = 1.8 mm

[mm]

Fluid mass flow

[g/s]

Fluid exit quality

HD1 O-O 56.5 10 66.5 1052 0 340+350 1784+1774

HD1 O-I 37.6 10 47.6 584 87+87 373+383 1784+1774

HD1 I-O & I-I 60.9 10 70.9 962 137+78+59 342+352 1784+1774

HD2 O-O 56.5 10 66.5 1052 0 296+306 1784+1774

HD2 O-I 37.6 10 47.6 584 87+87 265+275 1784+1774HD2 I-O & I-I 60.9 10 70.9 962 137+78+59 265+275 1784+1774

HD3 O-O 56.5 10 66.5 1052 0 168+178 1784+1774

HD3 O-I 37.6 10 47.6 584 87+87 201+211 1784+1774

HD3 I-O & I-I 60.9 10 70.9 1052 137+78+59 170+180 1784+1774

Heat Load and Tube Lengths for 9 Cooling Loops of an FPix Half-cylinder (typical for each of 4 half-cylinders)

CMS Upgrade Workshop April 27, 2010 12FPIX C02 Cooling

Cooling Loop Design Considerations

• Minimize the number of loops within a reasonable pressure drop limit• Allow the inner half-disk portions to be removed separate from the

outer half-disk portions• Use the C02 flow exiting the half-disks to cool the DC-DC converters

and Opto-isolators• The slightly larger tube on the return feed lines should minimize the

pressure drop from the additional heat load• The alternative is a separate loop but the loop must reach the port-cards

which need to be within the 600 mm cable reach of the half-disks• Use the 4 available copper lines to PP1 to provide 2 segments that

could be isolated in case of a coolant leak

CMS Upgrade Workshop April 27, 2010 13FPIX C02 Cooling

Outer Loop Flow Test

Model of a stainless steel tube embedded in a half-disk cooling ringstainless steel tube

prototype

• Prototype cooling loop of half-disk outer ring sent to CERN for testing• Cooling loop instrumented and connected for testing inside a freezer with C02 system• First round of results received last week and in process of comparing to calculations

CMS Upgrade Workshop April 27, 2010 14FPIX C02 Cooling

Summary

• Design of a 5 kW C02 cooling system is in the final details phase• The procurement of major items has started• The expected first operation of the system is in Fall 2010• Preliminary arrangement has been developed for the cooling tubes

within the half-cylinder• Pressure drop calculations are underway• Details of tube routing and connections are in process

• Initial results of the flow tests of a prototype cooling tube have been received and are being compared to predictions.