Papers by Keyword: Evaporating

Abstract: This paper has built a mathematical model for the evaporating characteristics of the grooved micro heat pipe’s thin film region and computed them in a specific working condition. The evaporating model of Wayner was employed in this mathematical model. The results from computation showed, for the H2O and NH3 as working fluid, at the beginning of the thin film region, the heat flux raised rapidly to a peak value and then declined to almost 0 also rapidly in a very short distance. Differently, for the Na and K as working fluid, the heat flux raised quickly but declined slower. Therefore, the alkali metals working fluids had larger area of high heat flux covered. The results indicated that the alkali metals working fluid has better evaporating characteristics for the high-temperature heat pipe than normal working fluids.

Abstract: In recent years in Japan, the demand of cryogenic fluids like a LH2, LNG is increasing because of the advance of fuel cell device technology, hydrogen of engine, and stream of consciousness for environmental agreement. On the other hand, as for fisheries as well, the use of a source of energy that environment load is small has been being a pressing need. We paid attention to the effective use of cold heat of the liquid fuel which is a cryogenic fluid. That method is to use a cold heat which an cryogenic fluid has, without a heat exchanger. The mixture of the extreme low temperature fluid and the normal temperature fluid becomes the cause which causes pressure vessel and piping system crush due to explosive boiling and rapid freezing. Therefore, we carried out the experiments related to promotion of evaporating cryogenic fluids, in the contact directly of the room temperature fluids and cryogenic fluids.