Unsteady Simulation of The Heat Transfer and Mixing for a Storage Hot Water Tank
The purpose of this study was to investigate the heat transfer and hot/cold water mixing in the tank of a new type gas storage water heater, which utilized top and bottom water inlet. The unsteady mixing process was simulated in the paper. The typical running circle process of storage water heater was heating—standby—draining—heating. Performances of these processes were different of the conventional water heater without top inlet and new type water heat with top inlet. 1) Heating process. The conventional one had a burner at the bottom of tank. Cold water was heated and then flowed upward driven by the buoyancy. The flow circle appeared in the tank because of density difference. The new type water heater set the burner at top of the tank. The hot water never flowed downward. 2) Standby process. After heating process, the water kept immobility. It was a purely heat transfer process from up to bottom of the tank or turn over. 3) Drain process. It was the real process users focus on since the hot water outlet opened. For conventional water heater, the cold water jet in the bottom of tank from one and only water inlet. It would not flow upward to mix with hot water because of the big density. So the temperature of outlet hot water would keep smoothly. For the new type water heater, a top water inlet jet parts of cold water into the tank to cool the combustion chamber surface. Water flux of the top water inlet would change by total water inlet to keep the constantly hot water temperature of outlet. A 3-D model was made to simulate all of these three processes to observe the mixing and heat transfer of the tank. Result showed that different mixing and heat transfer phenomenon appears in whole four processes.
gas water heater top water inlet mixing heat transfer simulation
Bu Qiu Xiaosong Zhang
Energy and environment department, Southeast University, Nanjing, 210093, China
国际会议
4th International Symposium on Heat Transfer and Energy Conservation(第四届传热与节能国际研讨会 ISHTEC2012)
广州
英文
1-5
2012-01-06（万方平台首次上网日期，不代表论文的发表时间）