Multi-objective Optimization of Heat Exchangers in Microminiature Refrigerator

Microminiature refrigerator(MMR)is wildly used in micro element cooling area.It is fabricated by novel etching,material growing,thinning and bonding technologies.The minimum size of its restriction area can be 1 μm.This paper presents a numerical optimization by employing the multi-objective method to obtain the best structural parameters with the goal of optimizing the MMRs high and low-pressure heat exchangers’heat transfer and pressure performance.The calculation results agree well with correlations in literature.The results showed that compared to the origin model the Nus-selt number Nu is increased by 5.8% and friction factor f is decreased by 25.7% in optimized high-pressure heat exchanger model,as for the optimized low-pressure heat exchanger model the Nu is increased by 14.5% and f is decreased by 2.3%.The patterns of Nu and f change with structural parameters are also obtained.This paper provides a new approach of MMR heat exchangers simulation and offers theoretical reference to the performance optimization.