マイクロチャネル熱交換器の熱流動現象の定量評価

Quantitative evaluation of thermal hydraulics phenomena in microchannel heat exchangers

伊能 慶太*; 梅川 尚嗣*; 網 健行*; 原山 勲  ; 栗田 圭輔  ; 飯倉 寛  

Ino, Keita*; Umekawa, Hisashi*; Ami, Takeyuki*; Harayama, Isao; Kurita, Keisuke; Iikura, Hiroshi

Recently, microchannel heat exchangers have begun to be used in air-conditioning units instead of ordinary fin-tube type heat exchangers. Although the microchannel heat exchanger offers several advantages, such as a large specific surface area, it also has disadvantages. One of them is the maldistribution of flow among parallel channels. To understand these phenomena, measuring the flow rate in each channel is quite important, but direct measurement has been very difficult. In this paper, the flow rate in each channel is evaluated using visualization images obtained by neutron radiography. The results provide information on flow characteristics, such as maldistribution and flow oscillation, and also confirm the validity of methods for estimating the flow rate.