NCSX

December 16, 2005

NCSX Vacuum Vessel Heating and Cooling system R&D

P. Goranson, B. Nelson

Dec 16, 2005 2

NCSX

First VVSA is coming soon

• Current Status– 1st VVSA delivery by end of March

– Heating and cooling system design complete pending specification of heaters

– Thermal Insulation design nearly complete

– Structural support design complete, in fabrication at PPPL

– I&C design nearly complete

Dec 16, 2005 3

NCSX

Vacuum Vessel ancillaries defined

VV ancillaries include:

- flux loops- coolant tubes - thermocouples- headers- diagnostic feed through flanges- lateral supports- pumping/personnel access port- heater tapes

Dec 16, 2005 4

NCSX

Cooling tube design modified to aid fabrication

• Original design based on standard 5/16 o.d. stainless steel tubing, formed to CAD-derived geometry data (per vendor input)

• No bids received from vendors• New design uses corrugated stainless tubing with

braided reinforcement• Standard product, easy to install, but will it work?

1.25

1/16

5/16 STUD

.062

Gasket omitted for clarity

1.0

Ø.375

R 0.44

0.645

0.4 DIA

Configuration change for braided tubing

0.505

Cross section at typical clamp

Dec 16, 2005 5

NCSX

Loose fill provides better thermal insulation

• Original concept used microtherm bats– Required custom flat pattern designs

for each of 8 layers– Thickness limited to 2 inches to provide

clearance for field period assy

• New design uses loose fill of nanogel beads– Inexpensive– Better insulation ( 1/3 heat leak)– Current product not rated to 350C, but

expect this will be available soon – adequate alternative is perlite,

but will this system work?

•Aerogel felt

around mod coil

Dec 16, 2005 6

NCSX

We need to test integrated H/C system

Goals

1 H/C tube design verfication1.1 Heat transfer to and from tube1.1.1 temp vs time1.1.2 what is hc?1.2 Attachment method(s) for tube1.3 Routing of tube1.4 Operation/durability up to 350C

2 Heater tape design verification2.1 Control of port temperature during bakeout2.2 Attachment, routing of tape2.3 Operation/durability up to 350C

3 Magnetic Loops3.1 Interaction / compatibility with heater3.2 Operation/durability up to 350C

4 Insulation system4.1 simulate boot4.2 simulate loose fill insulation

• Goals

• Maybe we can do this on the Rohwedder PVVS

Dec 16, 2005 7

NCSX

How would we set up Rohwedder PVVS?

• Cut port region from Rohwedder PVVS

• Ship port region of Rohwedder PVVS to ORNL

• Procure cooling tube and associated mounting hardware

• Borrow one or more prototype magnetic loops from PPPL

• Procure two or more port heater tapes with associated controls

• Procure set of thermocouples and associated mounting blocks

• Attach cooling tubes, heater tapes, magnetic loops, thermocouples in prototypical manner

Dec 16, 2005 8

NCSX

How would we set up Rohwedder PVVS?

• Fabricate one boot assembly to fit PVVS port

• Fabricate mockup of mod coil port opening

• Mount mod coil port opening in bottom of container

• Mount PVVS with port down in container

• Fill space around PVVS segment with loose fill insulation

• Heat PVVS by separate heater tapes

Dec 16, 2005 9

NCSX

How would we use Rohwedder PVVS?

• Heat PVVS segment to 150C and:– Demonstrate control of port temperature

with heater tape(s) on port extension– Check effectiveness of bead insulation

• Turn off heaters and check cooldown via flexible cooling lines

– Determine temperature gradient between tubes

– Determine heat transfer coefficient

• Repeat at various temperatures up to 350C

• Dismantle and inspect all parts for damage, degradation

Dec 16, 2005 10

NCSX

How much would this cost?

Dec 16, 2005 11

NCSXSummary