Direct refrigerant cooling has the advantages of low cost

high cooling efficiency

low weight

and high safety

and also problems of low evaporating temperature and uneven battery temperature in normal direct cooling refrigerant systems. In this study

the effectiveness of secondary throttling on the temperature regulation of a direct cooling plate was tested and verified. The results show that the direct cooling plate outlet pressure is increased while the superheat is reduced by adding a throttling device (fixed orifice device or a pressure-regulating valve with adjustable orifice) behind the cooling plate

thereby increasing the evaporation temperature and leading to better temperature uniformity. However

the throttle device with a fixed aperture cannot actively adjust the outlet pressure of the direct cooling plate

which increases as the thermal load increases. Therefore

it is difficult to control the battery temperature within an appropriate range when the thermal load changes. The throttle device with an adjustable aperture can adjust the direct cooling plate outlet pressure to a target value according to the operation load of the battery

which can not only avoid the evaporation temperature from being too low

but also improve the temperature uniformity.