R32, Swirl Evaporator, Hydraulic Characterization
To ensure reliability in miniaturized devices or processes with increased heat fluxes, decreasing available cooling surfaces have to be met by novel cooling methods. In order to meet this challenge, a new type of evaporator, the swirl evaporator, was developed. The swirl evaporator is a screw-shaped cylindrical evaporator with an internal diameter between 1 – 3 mm, which is inserted as a blind hole in components with high heat generation. The refrigerant is fed into the blind hole via a capillary, deflected by 180° in the drilling base and flows out of the evaporator again in a helical way (twist flow) against the inflow direction. The refrigerant is pressed against the hot wall by centrifugal forces. This results in an increased critical heat flux. The evaporator's design allows a compact size, making it suitable for a wide range of technical applications. To enable its design for industrial needs, a test stand has been developed. The hydraulic characterization was performed by varying the evaporator length. First experimental results show a linear relationship between swirl evaporator length and pressure loss.