Thermal effects of water immersion on spray cooling in non-boiling zone

Spray cooling shows significant advantages in thermal control of high heat flux components. However, rapid drainage problem with the spray chamber can affect the reliability and stability of the cooling system. It can be solved by means of immersion. The focus of this paper is to conduct a comparative study of the heat transfer performance between spray cooling (SC) and immersed spray cooling (ISC). It is proved that with reasonable control of immersion state and spray pressure, the immersion does not worsen the heat transfer, but even helps to enhance it with a maximum enhancement ratio of 12.2%. The immersion water temperature and spray pressure play a vital role in the ISC. Wide-angle nozzles are not suitable for ISC applications. The immersion deteriorates the spray cooling by up to 50.1% when the spray angle is 83°. This paper can be a guide to the structural design of the spray chamber.