DHE Chassis and Cooling

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Lynette Gordon
5 years ago
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1 DHE Chassis and Cooling DES Mechanical Workshop at FNAL November 2, 2005 Vaidas Simaitis High Energy Physics Group University of Illinois at Urbana-Champaign 1

2 6-SLOT + 4-SLOT CHASSIS 2

3 FAN MANIFOLDS ADDED 3

4 FANS ADDED 4

5 COOLING MANIFOLDS ADDED 5

6 HEAD EXCHANGERS ADDED 6

7 MAIN MANIFOLDS ADDED WITH HEAT SINK FOR THERMOELECTRIC COOLER 7

8 POWER SUPPLIES ADDED 8

9 POWER SUPPLY MANIFOLDS ADDED 9

10 DELRIN MOUNTING INSULATORS 10

11 MOUNTED TO INNER CYLINDER (1/4 SHOWN) 11

12 CONNECTOR BULKHEAD 12

13 WITH MODULE IN GREEN 13

14 Z-AXIS VIEW WITH R=52 ID CLEARANCE CYLINDER 14

15 WORST-CASE MODULE EXTRACTION 15

16 WHOLE ASSEMBLY CAN BE TILTED AT EITHER END FOR MODULE EXTRACTION 16

17 Z-AXIS VIEW WITH HEAT SHIELDS ADDED 17

18 BOTTOM PERSPECTIVE OF ENTIRE ASSEMBLY 18

19 TOP PERSPECTIVE OF ENTIRE ASSEMBLY 19

20 HEAT SHIELD SIZE

21 COOLING SYSTEM SIZE

22 RADIATING SURFACE A = 2x(12 x x x 22.5 ) = ~1500 in² = ~1 meter² L = Insulation thickness =.25 = 1/16 m l = thermal conductivity = ~ 0.03 W/mK for air If T-ambient= -20 C, T-electronics= 30 C then? T = 50 C Q = heat flow rate = la? T / L = 0.03 x 1 x 50 x 16 = 24 Watts 22

23 THERMOELECTRIC COOLER 1 Q-hot = heat released hot side = Q-cold + P-in where Q-cold = heat absorbed at cold side and P-in = electrical Power input T-hot = hot side temperature of thermoelectric = T-ambient + Q-hot x T where T = thermal resistance of the hot side heat exchanger? T = required temperature differential = T-hot T-cold 23

24 THERMOELECTRIC COOLER 2 T-ambient is in fact the temperature of the electronics, which is assumed to be 30 C The heat sink temperature rise can be 1 st approximated to be 10 C Then T-hot = 40 C If T-cold = -20 C then? T = 60 C Assume Q-cold = 10 W for each heat shield Assume T = 0.10 C/W (possibly?) 24

25 THERMOELECTRIC COOLER 3 If P-in = 100 W (this is hopefully worst case) Q-hot = Q-cold + P-in = 10W+100W = 110W T-hot = T-ambient + Q-hot x T = 30 C W x 0.1 C/W = 41 C which is close to the assumed value 25

26 THERMOELECTRIC COOLER 4 Single stage TE s are most efficient at a? T = 40 C ± 10 C We probably need a 2-stage TE for handling? T of 60 C or more We have not yet explored the specifications and pricing of these 2-stage TE s Yes, this is still all theoretical! 26

27 TOTAL HEAT LOAD The estimated average DC power for a dual backplane is ~350 Watts If power supply is 80% efficient, it must be producing another 70 W Add 2 TE s at 110 W each Add 2 fans at 30 W each TOTAL = 700 W Or 350 W for each of 2 heat exchangers 27

28 HEAT EXCHANGERS T-electronics assumed = 30 C If we assume T-liquid = 10 C? T = 20 C Performance required is 350 W / 20 C = 17.5 W/C Lytron M spec is ½ gpm with a liquid pressure drop of ~0.5 psi at an air flow of ~60 cfm with an air pressure drop of 0.2 inches of water (at 100 cfm, the drop is 0.3 ) 28

29 ? T OF COOLING WATER 1 gallon of water weighs 3784 grams ½ gallon/min = 1892 grams/min 1W = calories/min 350W = 5016 cal/min? T = 5016/1892 cal/g -> 2.65 C Can we run the two heat exchangers in each crate assembly in series, with a dt = 5.3 C? 29

30 FANS Should be routine For example: a Comair/Rotron Patriot PT2B3 is rated at 150 cfm at 0.3 drop running at 115 VAC at 60 Hz at 31 W. PT2D3 should be 75 cfm at 16 W, running at 1700 rpm instead of 3400 rpm 30

CC3060 TYPE 12 COMPACT CABINET COOLER AIR-TO-WATER FLUSH-MOUNT MODEL

CC3060 TYPE 12 COMPACT CABINET COOLER AIR-TO-WATER FLUSH-MOUNT MODEL CC3060 TYPE 12 CC3060 13 lbs 9,300 0.3 1 x 6 30 x 8-3/4 x 4 Efficiency: 68.8 Watts / C T based on average internal cabinet temperature. 2. CC3060 Rated cooling: 2,725 Watts mounted to an uninsulated 72