增材制造高性能微通道换热器模块化单元传热与压损实验

Experiments of Heat Transfer and Pressure Loss in a High-performance Additively Manufactured Modular Microchannel Heat Exchanger

面向微型燃气轮机能效提升迫切需求,针对其回热循环工况设计了一款适合应用增材制造技术加工的高性能微通道回热器。结合逆流式换热器的基础研究与金属增材制造的特点,设计了模块化的波纹板微通道换热器单元,采用激光选区熔融技术(SLM)完成不锈钢样机加工,并使用自行搭建的实验系统对其进行了性能测试。样件具有52个高度为0.7 mm的换热微通道,紧凑度超过1700 m^(2)/m^(3)。实验测试表明,该增材制造换热器在相对压损小于2%的条件下,平均Nu数相比传统方式加工的平板原表面换热器可提升88.9%,其关键性能参数在现有紧凑式换热器中具有先进性。

To meet the urgent need of efficiency improvement of micro gas turbines,a highperformance microchannel recuperator suitable for additive manufacturing processing is designed.Based on the basic theory of counter flow heat exchanger and the characteristics of metal additive manufacturing,a modular wavy plate microchannel heat exchanger is designed.The stainless-steel prototype is processed by laser selective melting technology,and tested experimentally.The heat exchanger unit contents 52 microchannels with height of 0.7 mm.The compactness of the prototype reaches more than 1700 m^(2)/m^(3).The experimental results show that average Nu number increases by 88.9%compared with the traditional flat primary surface heat exchanger under the condition of relative pressure loss less than 2%,and the key performance parameters proves the advancement of this heat exchanger among the existing compact heat exchangers.