Experimental radiator section with heat pipes: Creation experience, development work and life tests

The experience in designing the experimental section of a radiator with a single row stack of heat pipes streamlined with the coolant plane-parallel flow was dealt with. The radiator consisted of 14 sodium filled heat pipes (18 mm diameter and 714 mm length) welded into the collector-heat exchanger of the warming heat-coolant; columbium alloy (Nb-1Zr-0.1C) was used as structural material for both the radiator and heat pipes. Thermal and life tests were carried out on single heat pipes. It is found that the radiator experimental section of 14 columbium heat pipes with sodium as working fluid functioned successfully for 7,500 hr in the 850 to 950 C lithium temperature. The tests on sodium filled columbium heat pipes showed that long service life can be ensured with cleaning of sodium and pipe working surfaces, and preventing sodium from contamination during operation.