Experimental investigation of large area spray cooling with compact chamber in the non-boiling regime

• Temperature non-uniformity is expanded by increasing heat flux on large surface.
• Heat flux of 91.5 W/cm2 is achieved in non-boiling regime with pure water.
• Heat transfer is enhanced by changing of flow rate or height with multi-nozzle.
• Heat transfer is increased by 15% with 200 ppm surfactant compared with pure water.

The development trend of spray cooling system is adapting to strict working conditions such as high heat flux, large heating surface and complex fluid management. Therefore, for the purpose of cooling large heating surface in a compact space, this paper designed a novel multi-nozzle array and set up a test rig of spray cooling loop. The spray characteristics of the nozzle were tested by Phase Doppler Anemometer system, and the effects of temperature uniformity, flow rate, spray height and surfactant of 2-ethyl-hexanol on heat transfer performance of the spray cooling system were studied. According to the spray cooling curves obtained, the heat flux on the heating surface (30 mm × 30 mm) can reach 102.6 W/cm2 at least using surfactant and 91.5 W/cm2 using pour water. The temperature non-uniformity was expanded with increasing heat flux. The results simultaneously indicate that the heat transfer performance is closely associated with volume flow rate and spray height, while the performance is improved by increasing volume flow rate and optimizing spray height. In addition, trace amounts of 2-ethyl-hexanol surfactant added into the working fluid can enhance the heat transfer performance of spray cooling which is increased by 15% with 200 ppm 2-ethyl-hexanol surfactant compared with water added nothing.

Figure optionsDownload as PowerPoint slide