First results of a Freon 12 capillary pumped loop
Abstract
The design characteristics, the first experimental data and two thermal mathematical models (FLUINT and ZOOM) of a two phase freon 12 capillary pumped loop are presented. This loop mainly consists of two parallel evaporators and isolators, one condenser, one reservoir (to control the loop temperature), two adiabatic pipes (one for liquid and one for vapor) and instrumentation. Different kinds of cylindrical evaporators are tested. The main design characteristics of the evaporators is an axially grooved profile with a polyethylene wick. Experimental performances already obtained are encouraging (1800 Pa for the capillary pumped pressure with a 10 micron wick). Therefore, heat transport capability up to 750 kW/m can be envisioned for a similar ammonia loop. Up to 5000 W could be transported along an equivalent distance of 150 m (in a 20 mm straight vapor pipe at 20C with a 10 micron wick, neglecting the condenser and liquid return pipe pressure drop). Such a loop, today in development, is also presented.
- Publication:
-
, Fluids in Space
- Pub Date:
- June 1992
- Bibcode:
- 1992flsp.rept..261F
- Keywords:
-
- Breadboard Models;
- Capillary Tubes;
- Freon;
- Heat Transfer;
- Mathematical Models;
- Performance Tests;
- Temperature Control;
- Two Phase Flow;
- Cooling Systems;
- Feasibility;
- Loops;
- Spacecraft Temperature;
- Systems Engineering;
- Fluid Mechanics and Heat Transfer