This study presents theoretical considerations and results of a portable shell and tube heat exchanger in a solar water distiller system. The device is composed of a glass heat exchanger, which served as a condenser f...This study presents theoretical considerations and results of a portable shell and tube heat exchanger in a solar water distiller system. The device is composed of a glass heat exchanger, which served as a condenser for vapor condensing which were produced in black paint solar absorber. It was also composed of a tank for water source and a tank for produced distilled water. Shell and tube was designed and simulated using an implicit numerical scheme. Simulation results showed that accumulated mass water greatly depended on the inlet vapor temperature and volume, heat exchanger material, coolant water temperature and volume. Thus, changing the material from stainless steel to glass in the same condition （vapor temperature, vapor volume, coolant temperature and coolant volume）. These inexpensive shell and tube heat exchangers permitted to produce 40 litre/day, distilled water from vapor with 378 K inlet temperature in atmosphere pressure. If inlet pressure increases, vapor temperature will decline and thereupon, heat exchanger＇s efficiency tangibility will increase.展开更多
For utilization of the residual heat of flue gas to drive the absorption chillers,a lithium-bromide falling film in vertical tube type generator is presented.A mathematical model was developed to simulate the heat and...For utilization of the residual heat of flue gas to drive the absorption chillers,a lithium-bromide falling film in vertical tube type generator is presented.A mathematical model was developed to simulate the heat and mass coupled problem of laminar falling film evaporation in vertical tube.In the model,the factor of mass transfer was taken into account in heat transfer performance calculation.The temperature and concentration fields were calculated.Some tests were conducted for the factors such as Re number,heating flux,the inlet concentration and operating pressure which can affect the heat and mass transfer performance in laminar falling film evaporation.The heat transfer performance is enhanced with the increasing of heat flux.An increasing inlet concentration can weaken the heat transfer performance.The operating pressure hardly affects on heat and mass transfer.The bigger inlet Re number means weaker heat transfer effects and stronger mass transfer.The mass transfer obviously restrains the heat transfer in the falling film solution.The relation between dimensionless heat transfer coefficient and the inlet Re number is obtained.展开更多
文摘This study presents theoretical considerations and results of a portable shell and tube heat exchanger in a solar water distiller system. The device is composed of a glass heat exchanger, which served as a condenser for vapor condensing which were produced in black paint solar absorber. It was also composed of a tank for water source and a tank for produced distilled water. Shell and tube was designed and simulated using an implicit numerical scheme. Simulation results showed that accumulated mass water greatly depended on the inlet vapor temperature and volume, heat exchanger material, coolant water temperature and volume. Thus, changing the material from stainless steel to glass in the same condition （vapor temperature, vapor volume, coolant temperature and coolant volume）. These inexpensive shell and tube heat exchangers permitted to produce 40 litre/day, distilled water from vapor with 378 K inlet temperature in atmosphere pressure. If inlet pressure increases, vapor temperature will decline and thereupon, heat exchanger＇s efficiency tangibility will increase.
文摘For utilization of the residual heat of flue gas to drive the absorption chillers,a lithium-bromide falling film in vertical tube type generator is presented.A mathematical model was developed to simulate the heat and mass coupled problem of laminar falling film evaporation in vertical tube.In the model,the factor of mass transfer was taken into account in heat transfer performance calculation.The temperature and concentration fields were calculated.Some tests were conducted for the factors such as Re number,heating flux,the inlet concentration and operating pressure which can affect the heat and mass transfer performance in laminar falling film evaporation.The heat transfer performance is enhanced with the increasing of heat flux.An increasing inlet concentration can weaken the heat transfer performance.The operating pressure hardly affects on heat and mass transfer.The bigger inlet Re number means weaker heat transfer effects and stronger mass transfer.The mass transfer obviously restrains the heat transfer in the falling film solution.The relation between dimensionless heat transfer coefficient and the inlet Re number is obtained.
