Development And Test Results Of Spray Cooling In A Closed Loop
- Paper number
IAC-07-C2.7.06
- Author
Dr. Zhang hongxing, China Academy of Space Technology (CAST), China
- Year
2007
- Abstract
A visual closed-loop spray cooling test setup was established for the high heat flux cooling, through which the experimental phenomena in the visual chamber can be directly observed. The cooling area is 1 cm2, and the high heat flux heater can provide a heat flux of more than 600W/cm2. The spray nozzle was installed to the spray chamber and sealed up with two “O” shape rings, and therefore, the spray nozzle could be moved up and down. The spray distance from the spray nozzle to the heat surface can be adjusted from 4 to 22 mm. The working fluid is water, and the fluid circulation is sustained by a magnetic gear pump, which could adjust the loop flow rate from 2L/h to 5L/h. 20 T-type thermocouples, 2 pressure sensors and a flow rate sensor were fixed in the loop to monitor the concerned parameters. The steady state and transient characteristics of the spray cooling system was investigated. In the test, the spray cone, angle, atomization effect, liquid film on the heat rejecting surface, and vapor/liquid interface in the spray chamber could be observed through the visual shell of the spray chamber. The effects of the heat flux value, the spray distance, the sink temperature, the subcooling degree of the return liquid on the heat transfer performance and the evaporation efficiency of the spray liquid were analyzed. The transient operating characteristics of the spray cooling system were also investigated. The operating features during the startup and shutdown were analyzed, and the right startup and shutdown orders of the heater, pump, and the refrigerator were obtained. The operation ability during a heat load rise or drop was also validated.
- Abstract document