Abstract
A two-phase closed-loop thermosyphon is a device which transports heat energy from a heat source to a sink under the body force field and has many practical applications. The critical heat flux of this thermosyphon is larger than that of a non-loop thermosyphon, because the flooding phenomenon occurring in the no-loop one does not occur. In addition, there is another merit that the evaporator and the condencer can be installed in comparatively arbitrary position because these are interconnected by piping. In most previous investigations of the two-phase closed-loop thermosyphons, overall heat resistances were measured. The overall heat resistance, however, consists of three heat resistances; the heat resistances in the evaporator and the condenser, and the transport resistance in the interconnecting pipe. Therefore, we should consider these heat resistances separately. In the present study, we took note of the heat resistances (or heat transfer coefficients) of the evaporator and the condenser. The experiment was performed using two experimental setups and three kinds of test liquid. And, the effects of rotation angle, heat flux, inside temperature (or inside pressure) and liquid charge on the heat transfer coefficients were investigated.
