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25.03.2014 NSW/MM Layout & Design Working Group

GAS DISTRIBUTIONGAS DISTRIBUTION SYSTEM & FLOW STUDIES OF MM-NSW SYSTEM & FLOW STUDIES OF MM-NSW

T. Alexopoulos, S. Maltezos, S. Karentzos T. Alexopoulos, S. Maltezos, S. Karentzos

National Technical University of AthensNational Technical University of Athens

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25.03.2014 NSW/MM Layout & Design Working Group

• Updated design and configuration of the gas distribution systemUpdated design and configuration of the gas distribution system

• Results from the simulation (“Pipe-Flow”)Results from the simulation (“Pipe-Flow”)

• Gas Flow StudiesGas Flow Studies

Outline -- UpdatesOutline -- Updates

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25.03.2014 NSW/MM Layout & Design Working Group

What is available for the gas system?

Total gas volume is 6 m3 (Ar:CO2 93:7 at atm. pressure)

Flow rate (renewals): ≤ 10 volume changes a day (flow rate ~2500 l/h)

Existing CSC gas racks (Ar:CO2 80:20 at atm. pressure) with 16 channels/rack can be reused (1 rack/wheel)

Existing MDT gas racks (Ar:CO2 93:7 at 3 bar) with 17 channels/rack can be easily adapted to atm. pressure (1 rack/wheel)

For each wheel:16 sectors x 2 typeMM/sector x 2 MP/typeMM = 64 Multiplet(MM types: LM1&2 or SM1&2)

we use 16 channels/wheel A gas channel serves 4 MP or 2 wedges

LM1

LM2

SM

2S

M1

Total cost ~13 KCHF/year for r =10 volume_changes/day

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25.03.2014 NSW/MM Layout & Design Working Group

LM1

LM2

wedge

gas-inlet

gas-outlet

impedance

Gas manifold

multiplet

multiplet

LM1

LM2

impedance

Gas manifold

multiplet

multiplet

A g

as c

han

nel

Gas manifoldGas manifold

d=10 mm

d=12 mm

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25.03.2014 NSW/MM Layout & Design Working Group

Individual flow rate in each type of MMFeasible to manipulate the flow rates in a

controllable way

Impedances

MM detectors(LM1+LM2, SM1+SM2)

Gas input

Gas outputFlow rate Qt

Qi+1

Qn

QiZi

Zi+1

Z8

Updated impedancesUpdated impedances

In the case that we would like to accomplish individual flow rates among the MMs, according to their renewal rates, we have to solve analytically the piping network (the pressure – flow rate relation is, in principle, non-linear). Use “Pipe-Flow” simulation.

One impedance will serve two multiplets (LM1+LM2 or SM1+SM2 inner or outer) . We need 64 impedances in total of two different characteristic curves.

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The inner LM1+LM2 multiplets is supplied by 4 channels (Ch. 1, 2, 3, 4)

Gas distribution for LM1+LM2 Inner MP Gas distribution for LM1+LM2 Inner MP –– “PipeFlow” “PipeFlow”

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Simulation results: zoom at sectors 1 Simulation results: zoom at sectors 1 & 3& 3

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25.03.2014 NSW/MM Layout & Design Working Group

Gas distribution for SM1+SM2 Inner Gas distribution for SM1+SM2 Inner MP MP

The inner SM1+SM2 multiplets is supplied by 4 channels (Ch. 5, 6, 7, 8)

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Simulation results: zoom at sectors 2 Simulation results: zoom at sectors 2 & 4& 4

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Simulation results: Inlet / Outlet Simulation results: Inlet / Outlet pressurepressure

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Simulation results: Gas flow variation Simulation results: Gas flow variation

MM DET. LM1+LM2 SM1+SM2

FLOW Q(l/h) Q(l/h)

1 25.08 16.38

2 25.09 16.39

3 24.84 16.27

4 24.83 16.26

5 24.97 16.33

6 24.98 16.33

7 25.32 16.49

8 25.12 16.40

     

MEAN 25.03 16.36

RMS 0.16 0.08

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0.5mm

2mm2mm

Gas Flow in LM1, radially Geometry:Geometry:

dhole = 0.5mm,

dbz = 5mm, din = dout = 2mm. Buffer zone:

1. nhole (1) = 13

2. nhole (2) = 17

5mm1

2

LM1

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Simulationof gas flow in LM1 : total time=2000 s

Air

Ar:CO2

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Comparison………………………………………………………………………………………………………………………

…………………………………………………………………a. plus 2 “outboard”holes b. without the 2 “outboard” holes

Air

Ar:CO2

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LM1 side”wall” buffer zone Geometry : nholes = 12. Mixed diameters (Model E-like).

OUTLEOUTLETT

INLETINLET

0.5

4x0.75

4x0.75

1x1.00

1x1.00

0.5

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Plus center hole

Air

Ar:CO2

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25.03.2014 NSW/MM Layout & Design Working Group

LM1 and LM2

outlet outlet

InletInlet

d = 2mmd = 2mm

d = 2mm d = 2mm

d = 2mmd = 2mm

d = 5mm

d = 5mm

d = 5mm

d = 5mm

5mm

2mm

0.5mm

Geometry:Geometry: dhole = 0.5mm

dbz = 5mmBuffer zone:

1. nhole = 13

2. nhole = 17

3. nhole = 17, dhole = 0.5mm, 7 central dhole = 1mm

4. nhole =151

2

3

4

LM2

LM1

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LM1 and LM2

Air

Ar:CO2

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• The configuration in which the gas goes through multi-planes instead of single planes-layer has been studied and simulated by using the “Pipe Flow”. We assumed 16 gas channels per Wheel.

• The functional curves of the impedances have been updated. In this configuration we need 32 impedances per Wheel.

• From the simulation “Pipe-Flow” conclude that the gas flow through the multi-planes seem adequate uniform.

• Individual plane-layer gas flow simulation has been performed to study the uniformity of the gas flow.

• More work on model of gas diffusion through mesh is in progress…

Summary & on going workSummary & on going work