飞行器百千瓦级相变储热换热器性能仿真研究

Simulation Study on Performance of 100kW Class Phase Change Thermal Storage and Heat Exchanger for Aircraft

机载激光武器每次工作时会产生几百千瓦的废热,国外研究机构普遍采用相变储热换热器,对其进行短时存储、长时排散。基于此,针对国际先进相变储热换热器技术进行探索性研究,提出一种三通道板翅式相变储热换热器构型,通过数值模拟的方式,定量分析了换热器主要结构参数对工作性能的影响。结果表明,热流体出口温度随相变材料通道翅片高度的增加而下降,且随流体通道翅片高度和翅片节距的增加而上升。此外,换热器内部区域存在低效储热区、高效储热区和控温缓冲区3个部分,需要通过设置多流程的方式,以确保蓄热期间内热流体出口温度始终满足设计要求。

Airborne laser weapons produce hundreds of kilowatts of waste heat during its working process,therefore,foreign research institutions generally adopted phase change thermal storage and heat exchangers to storage the waste heat in a short time and then release it slowly.Based on this,a kind of three-channel plate-fin heat exchanger was proposed to conduct an exploratory research on the international advanced technology of phase change thermal storage and heat exchanger.Then,the performance of main structure parameters of this heat exchanger was analyzed quantitatively by numerical simulations.Corresponding to these results,the outlet temperature of hot fluid decreases with the increasing fin height for phase change material channels,and increases when the fin height for fluid channels and fin pitch for all channels grow.In addition,it was found that the internal region of this heat exchanger can be divided as“low-efficiency heat storage zone”,“high-efficiency heat storage zone”and“temperature buffer”.To ensure that the hot fluid outlet temperature meets the requirement of design throughout this whole period of heat storage,it is necessary to adopt a design of multistage flow paths for this heat exchanger.