A Study on the Flow Instability in Evaporator of Gravity Separate Type Heat Pipe

摘要

The flow characteristics and instability in the small inclination angle evaporator of Gravity Separate Type Heat Pipe (GSTHP) were studied. Flow patterns were investigated by a quartz glass tube with a Φ25 × 2 mm in evaporator of GSTHP. Two types of flow instabilities occurred, which are the flow pattern transition instability and density wave instability. The effects on the flow instability, such as inlet subcooling, heat flux, pressure, and outlet throttle resistance, were determined in the modeling experiment within the following parameter ranges: the inlet subcooling T_(sub), = 8～28℃, the heat flux q = 10～40 kW/m~2 and the throttle coefficient K_i = 0.5～0.75. The limits of the flow pattern transition instability and the density wave instability were obtained.