Heat-exchanger concepts for neutral-beam calorimeters
Abstract
Advanced cooling concepts that permit the design of water cooled heat exchangers for use as calorimeters and beam dumps for advanced neutral beam injection systems were evaluated. Water cooling techniques ranging from pool boiling to high pressure, high velocity swirl flow were considered. Preliminary performance tests were carried out with copper, inconel and molybdenum tubes ranging in size from 0.19 to 0.50 in. diameter. Coolant flow configurations included: (1) smooth tube/straight flow; (2) smooth tube with swirl flow created by tangential injection of the coolant; and (3) axial flow in internally finned tubes. Additionally, the effect of tube L/D was evaluated. A CO2 laser was employed to irradiate a sector of the tube exterior wall; the laser power was incrementally increased until burnout occurred. Absorbed heat fluxes were calculated by dividing the measured coolant heat load by the area of the burn spot on the tube surface. Two six element thermopiles were used to accurately determine the coolant temperature rise. A maximum burnout heat flux near 14 kW/sq cm was obtained for the molybdenum tube swirl flow configuration.
- Publication:
-
Presented at the 9th Symp. on Eng. Probl. of Fusion Res
- Pub Date:
- October 1981
- Bibcode:
- 1981epfr.sympR..26T
- Keywords:
-
- Axial Flow;
- Calorimeters;
- Carbon Dioxide Lasers;
- Heat Exchangers;
- Heat Flux;
- Liquid Cooling;
- Neutral Beams;
- Tubes;
- Beam Injection;
- Copper;
- Heat Measurement;
- Inconel (Trademark);
- Molybdenum;
- Fluid Mechanics and Heat Transfer