Based on the physical model of capillary pumped loop (CPL) system, the phenomena of pressure oscillation are simplilied and analyzed. From a set of non-linear differential equations, the influence ofsystem parameters ...Based on the physical model of capillary pumped loop (CPL) system, the phenomena of pressure oscillation are simplilied and analyzed. From a set of non-linear differential equations, the influence ofsystem parameters on the performance of the CPL is discussed, including the working temperature(the Set point), loop resistance, vapor volume etc. From the analysis, some measures were taken tohoprove the performance of the loop. Meanwhile, the reason why the deprive of the CPL occurs duringthe operation is given by analyzing the theoretical calculation results.展开更多
An overall two-dimensional numerical model of the miniature flat plate capillary pumped loop (CPL) evaporator is developed to describe the liquid and vapor flow, heat transfer and phase change in the porous wick str...An overall two-dimensional numerical model of the miniature flat plate capillary pumped loop (CPL) evaporator is developed to describe the liquid and vapor flow, heat transfer and phase change in the porous wick structure, liquid flow and heat transfer in the compensation cavity and heat transfer in the vapor grooves and metallic wall. The entire evaporator is solved with SIMPLE algorithm as a conjugate problem. The effect of heat conduction of metallic side wall on the performance of miniature flat plate CPL evaporator is analyzed, and side wall effect heat transfer limit is introduced to estimate the performance of evaporator. The shape and location of vapor-liquid interface inside the wick are calculated and the influences of applied heat flux, liquid subcooling, wick material and metallic wall material on the evaporator performance are investigated in detail. The numerical results obtained are useful for the miniature flat plate evaporator performance optimization and design of CPL.展开更多
This paper presents the experimental investigation on the heat transfer chaxacteristics in inverted evaporator of Micro/Miniature Capillary Pumped Loop (MCPL). The evaporation heat transfer coefficients as a function ...This paper presents the experimental investigation on the heat transfer chaxacteristics in inverted evaporator of Micro/Miniature Capillary Pumped Loop (MCPL). The evaporation heat transfer coefficients as a function of the heat flux density, the geometrical sizes of capillary wick structure and the vapor grooves are shown. Qualitative analysis of the heat transfer characteristics of the inverted evaporator of MCPL is also made.展开更多
The disturbance, caused by the boiling Phenomena in the inverted meniscus ac evaporator, is of great importancein the normal operation of the CPL, especially When the heat load is low. By theoretical and experimental ...The disturbance, caused by the boiling Phenomena in the inverted meniscus ac evaporator, is of great importancein the normal operation of the CPL, especially When the heat load is low. By theoretical and experimental studies onthis issue, it shows that the evaporator of the CPL operates in a mode of boiling in the Wick. By solving a set ofmomentum equations, it concludes that, this kind of boiling Phenomena in the wick cause no notable negativeinfluence on the normal peiformance of the CPL, although there really edests some adVerse influence during theCPL start-up. Addihonally, the causes of the dry-out of the evaporator under low heat load are conducted in thepaper. The conclusions are verified by subsequent experiments. More details about the experiments are alsodescribed in the paper.展开更多
文摘Based on the physical model of capillary pumped loop (CPL) system, the phenomena of pressure oscillation are simplilied and analyzed. From a set of non-linear differential equations, the influence ofsystem parameters on the performance of the CPL is discussed, including the working temperature(the Set point), loop resistance, vapor volume etc. From the analysis, some measures were taken tohoprove the performance of the loop. Meanwhile, the reason why the deprive of the CPL occurs duringthe operation is given by analyzing the theoretical calculation results.
文摘An overall two-dimensional numerical model of the miniature flat plate capillary pumped loop (CPL) evaporator is developed to describe the liquid and vapor flow, heat transfer and phase change in the porous wick structure, liquid flow and heat transfer in the compensation cavity and heat transfer in the vapor grooves and metallic wall. The entire evaporator is solved with SIMPLE algorithm as a conjugate problem. The effect of heat conduction of metallic side wall on the performance of miniature flat plate CPL evaporator is analyzed, and side wall effect heat transfer limit is introduced to estimate the performance of evaporator. The shape and location of vapor-liquid interface inside the wick are calculated and the influences of applied heat flux, liquid subcooling, wick material and metallic wall material on the evaporator performance are investigated in detail. The numerical results obtained are useful for the miniature flat plate evaporator performance optimization and design of CPL.
文摘This paper presents the experimental investigation on the heat transfer chaxacteristics in inverted evaporator of Micro/Miniature Capillary Pumped Loop (MCPL). The evaporation heat transfer coefficients as a function of the heat flux density, the geometrical sizes of capillary wick structure and the vapor grooves are shown. Qualitative analysis of the heat transfer characteristics of the inverted evaporator of MCPL is also made.
文摘The disturbance, caused by the boiling Phenomena in the inverted meniscus ac evaporator, is of great importancein the normal operation of the CPL, especially When the heat load is low. By theoretical and experimental studies onthis issue, it shows that the evaporator of the CPL operates in a mode of boiling in the Wick. By solving a set ofmomentum equations, it concludes that, this kind of boiling Phenomena in the wick cause no notable negativeinfluence on the normal peiformance of the CPL, although there really edests some adVerse influence during theCPL start-up. Addihonally, the causes of the dry-out of the evaporator under low heat load are conducted in thepaper. The conclusions are verified by subsequent experiments. More details about the experiments are alsodescribed in the paper.