SPD cooling Test benchPreliminary results

CERN (Geneva) 12-01-11

A. FrancesconUniversità & INFN Padova

1

Summary

• Description of the test bench experimental setup

• Clean filters characterization• Masked filters tests• Pollution test

2

Why a test bench

Problems in the SPD cooling system (and related losses in detection efficiency)

+Difficult theoretical evaluation of the problem

=Experimental test bench

3

The plant

The ideal plant:- Exact replica of the real plant- Many measuring points (T, p, flow) along the stave and the whole plant

Temporary plant:- Similar to the real plant (smaller scale)- Many measuring points- Being upgraded for larger flow

Meanwhile:We use a thermosiphon plant built by the EN/CV/DC group’’

4

Two-phase thermosiphon plant

ChillerCondenser

Dummy Load

18𝑚

Natural circulation of the Fluid (C4F10)- On the liquid phase by gravity- On the gas phase by pressure difference 5

Test bench schema

PP4 filter and

pressure

PP3 filter and

pressure6

Test bench

7

Setup characteristics

1) Available pressure difference (supply-return) dp= ~ 2,5 bar

2) Nominal flow ~ 3,7 g/s (without filters)

3) The sector is an exact replica of an SPD sector from the mechanical/hydraulic point of view;The only difference is that in this case power on the sector is not generated by the detector but with a power supply (so the power can be adjusted very simply).

8

Filters characterization

Clean 60 um filter Clean 20 um filter

0 0.5 1 1.5 2 2.5 3 3.5 40

0.1

0.2

0.3

0.4

0.5

0.6

DP vs Flow

0 W50 W100 W150 W200 W

Flow [g/s]

Dp [b

ar]

0 0.5 1 1.5 2 2.5 3 3.50

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

Dp vs Flow

0 W50 W100 W150 W200 W250 W

Flow [g/s]

Dp

[bar

]

9

Filters characterization

N.B. This is the situation that we have now in the cavern:- 60 um filter in PP4- 60 um filter in PP3

N.B. Dp is measured only on the secon filter (PP3).0 0.5 1 1.5 2 2.5 3 3.5

0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4

0.45

Pressure drop on the second filter vs Flow

0 W100 W150 W

Flow [g/s]

Dp [b

ar]

Two 60 um clean filters

in series

10

Filter Dp and flow variations with the power applied to the sector

60 um clean filter

0,5 g/s decrease

100 mbardecrease

11

Flow variations with the power applied to the sector for different flowrate

0 50 100 150 200 250 3000

0.5

1

1.5

2

2.5

3

2,5 g/s2 g/s1,5 g/s1 g/s

Power [W]

Flow

[g/s

]

Clean 60 um filter

12

Impedance of different filter combinations

13

Bubbles formation

0 1 2 3 4 5 6 7 8 90

0.5

1

1.5

2

2.5

3

3.5

4

PP4 [bar]

PP4 [bar]

Starting bubble formationPP4=2,13 bar

0 1 2 3 4 5 6 7 8 90

5

10

15

20

25

T [°C]

T [°C]Starting bubble formation T=18°C

bar

Closing point

°C

Closing point 14

Bubbles formation point on the p-h diagram

Liquid

Liquid+Gas

GasT=18°CP=2,13 bar

15

Masked filters3 different type of masked filter used (all clogged with epoxy glue):

- Spot masked filter: filter clogged with 6 dot (dot diameter ~1 mm & clogged surface ~50% )

- Diffuse masked filter: filter clogged in a diffusive way (clogged surface ~50%)

- Center masked filter: filter clogged in the middle part of the surface (clogged surface ~65%)

Spot filter Center filter

16

Influence of the clogging type on the flow

0 1 2 3 4 5 6 7 80

0.5

1

1.5

2

2.5

3

3.5

4

Flow vs Valve position @ 0 W

spotdiffusecenterClean 60 um filter

Valve position

Flow

[g/s

]

17

Dp vs Flow for different clogged filters

0 0.5 1 1.5 2 2.5 3 3.5 40

0.1

0.2

0.3

0.4

0.5

0.6

Dp vs Flow @ 0 W

Spotdiffusecenter60 um clean

Flow [g/s]

Dp [b

ar]

18

Pollution tests

4 kind of Goodfellow calibrated metal particles:

1) 0,4-12 um carbon vitreous powder2) 20-50 um carbon vitreous powder3) 80-200 um carbon vitreous powder <75 um carbon powder4) <75 um carbon powder

Test procedure:

1) The powder has been introduced in the pipe upstream both filters2) Vacumm has been made downstream both filters3) Flow and Dp across the PP3 filter has been evaluated for different flowrate and different power applied to the sector

19

Powder sample

Due to technical problems- Difficult handling of very small

particles- Powder adehesion on the pipe wall

and on the instruments- …

the real amount of powder is ~50%.

0,4-12 um carbon vitreous powder0,25 g of powder

20

After the insertion of 0,25 g (nominal) of 0,4-12 um carbon vitreous powderNote PP4 (bar) Dp (bar) Flow (g/s) Valve fully open Values just after the opening of the valve

3,456 0,599 2,845

2 min. later 3,450 0,596 2,833 133 W applied on the sector

3,514 0,547 2,676

165 W applied on the sector

3,527 0,522 2,622

220 W applied on the sector

3,562 0,501 2,551

0 W applied on the sector 3,445 0,599 2,827

N.B. With clean 60 um filter and clean circuit:Valve fully open PP4=3,67 bar Dp=0,48 bar Flow=3,5 g/s

With epoxy glue 50% diffuse clogged filter:Valve fully open PP4=3,665 bar Dp=0,484 Flow=3,368 g/s

After the insertion 0,5 g (nominal) of powder:Valve fully open PP4=2,47 bar Dp=0,355 Flow=1,155

Pollution test: 0,4-12 um

21

Pollution test: 80-200 um

0 0.5 1 1.5 2 2.5 3 3.5 4 4.50

0.5

1

1.5

2

2.5

3

3.5

4

0 W powder flow0 W nominal flow (without filter)0 W 60 um filter flowFl

ow [g

/s]

I insertion

II insertion

Stop&Start with vacuum

III insertion

Stop&Start

22

Pollution test: 20-50 um

0 0.5 1 1.5 2 2.5 3 3.53.35

3.4

3.45

3.5

3.55

3.6

3.65

3.7

3.75

3.8

0 W powder flow0 W nominal flow (without filter)0 W 60 um filter

Flow

[g/s

]

Stop&Start

I,II and III insertion

Steps

23

Pollution test: <75 um

0 0.5 1 1.5 2 2.5 3 3.50

0.5

1

1.5

2

2.5

3

3.5

4

0 W powder flow0 W nominal flow (without filter)0 W 60 um filter100 W powder flowFl

ow [g

/s]

II insertion

IV insertion

I insertionIII insertion

24

Stepsteps

Pollution test: 0,4-12 um (small amount)

0 1 2 3 4 5 6 7 80

0.5

1

1.5

2

2.5

3

3.5

4

0 W powder flow0 W nominal flow (without filter)0 W 60 um filterFl

ow [g

/s]

Powder insertion

Stop&Start

Stop&Start with

vacuum

25

Inserted another little amount (~ 0,05 g) of 0,4-12 um carbon powder

Note Power [W]

PP4 [bar] Dp [bar] Flow [g/s]

Powder inserted 0 W 2,315 0,050 0,650

Stop&Start with pipe shaking 0 W 2,270 0,050 0,495

PP4 filter placed in PP3 position

0 W 4,045 1,519 1,484

26

Conclusions

• Powder clogging results to be more effective than epoxy glue clogging

• Powder crossing through the PP4 filter and following deposition on PP3 filter observed

• Flow variation with Stop&Start observed

27

28

29

Filter characterization

30

Clean 20 um filter

31

Two clean 60 um filter in series

0 0.5 1 1.5 2 2.5 3 3.50

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4

0.45

Pressure drop on the second filter vs Flow

0 W100 W150 W

Flow [g/s]

Dp [b

ar]

32

Spot clogged filter: filter clogged with 6 dot (approx. diameter 1 mm & approx. clogged surface 50% )

33

Center clogged filter:filter clogged in the middle part of the surface (approx. clogged surface 65%)

34

0,4-12 um carbon vitreous powder0,25 g of powder

35

Diffuse clogged filter:filter clogged with 6 dot (approx. diameter 1 mm & approx. clogged surface 50% )

36

Two portions Of 0,4-12 um carbon powder inserted in the same time (0,5 g in total)

0 20 40 60 80 100 120 140 1600

0.5

1

1.5

2

2.5

3

Flow [g/s]PP4 [bar]

Flow [g/s]

PP4 [bar]

37

80-200 um carbon vitreous powder0,2 g inserted in different times

Note Power [W]

PP4 [bar] Dp [bar] Flow [g/s]

I insertion 0 W 3,360 0,498 2,819

100 W 3,390 0,470 2,715

II insertion 0 W 3,305 0,460 2,8

100 W 3,350 0,430 2,684

Stop&Start 0 W 3,280 0,460 2,815

NIGHT STOPRestart after vacuum

0 W 3,310 0,490 2,778

III insertion 0 W 2,185 0,073 0,776

100 W 2,224 0,075 0,749

38

-75 um carbon powder~ 0,15 g inserted in different times

Note Power [W] PP4 [bar] Dp [bar] Flow [g/s]

I insertion 0 W 2,777 0,173 2,235

100 W 2,822 0,169 2,192

II insertion 0 W 2,742 0,172 2,183

100 W 2,802 0,166 2,132

III insertion 0 W 2,565 0,147 1,898

100 W 2,624 0,138 1,839

IV insertion 0 W 2,422 0,102 1,487

100 W 2,464 0,101 1,457

39

20-50 um carbon vitreous powder~ 0,15 g inserted in different times

Note Power [W] PP4 [bar] Dp [bar] Flow [g/s]

I insertion 0 W 3,015 0,217 2,650

100 W 3,075 0,204 2,551

II insertion 0 W 2,650 0,146 2,135

100 W 2,715 0,138 2,065

III insertion 0 W 2,168 0,032 0,915

100 W 2,190 0,030 0,895

Stop&Start 0 W 2,138 0,040 0,795

40

Test with a little amount (~ 0,05 g) of 0,4-12 um carbon powder

Note Power [W] PP4 [bar] Dp [bar] Flow [g/s]Starting condition(before inserting powder)

0 W 3,312 0,311 3,026

Powder insertion 0 W 3,031 0,337 2,495Stop&Start 0 W 2,885 0,323 2,238Stop&Start 0 W 3,373 0,663 2,489Stop&Start with vacuum 0 W 3,162 0,540 2,060Stop&Start 0 W 3,463 0,685 2,255Start&Stop with vacuum(PP3 filter replaced)

0 W 3,120 0,224 2,600

Stop&Start (with pipe shaking)

0 W 3,134 0,236 2,670