| Heat Source Tower is derived from traditional cooling tower and can provideheating in winter as an alternative to boiler, hence combines the functions of cooling,heating and domestic hot water. Heat Source Tower is currently in its infancy, and thestudy of its inner heat and mass transfer is scarce. At present, its application in practicalprojects is limited, mainly to hot summer and cold winter region south of the YangtzeRiver. In order to promote Heat Source Tower in hot summer and cold winter region,this thesis carried out theoretical analysis, numerical simulations and experiments tostudy the heat and mass transfer process of open-type reverse-flow heat source towerin winter, as well as the heating performance, economy and energy saving of open-typeheat source tower heat pump. The main work includes:Firstly, instead of the assumptions in traditional cooling tower models where theLewis number is supposed to be1, heat and mass transfer coefficients are assignedseparately to establish the winter heat and mass transfer mathematical model foropen-type reverse-flow heat source tower. The mathematical model is solved bydiscretization, and the result was compared with in situ measurement. It is found thatthe results of the mathematical model has favorable accuracy. Also, a software forcalculating the winter performance of open-type reverse-flow heat source tower hasbeen customized with C++language.Secondly, the software was used to analyze the vertical distribution of each relatedparameters in the filing material in heat and mass transfer process of open-typereverse-flow heat source tower. The effect of different operating conditions andstructure configurations on heat and mass transfer performance of open-typereverse-flow heat source tower has been studied. And the adjustment of condense watersystem in winter has been discussed.Then, with the consideration of the effects of five factors, i.e. unit part load ratio,inlet temperature of condenser, inlet temperature of evaporator, condenser water massflow rate, and evaporator water mass flow rate, an energy efficiency model for heatsource tower heat pump unit in variant operation conditions was developed bydata-fitting, based on the performance data of a screw heat source heat pump unitprovide by a manufactory. The model is validated with41groups of measurements andthe model shows favorable accuracy. Then, a coupled model of heating energy efficiency of open-type reverse-flowheat source tower under variant operating conditions was established, based on thewinter heat and mass transfer model as well as the variant operation condition model.And a winter energy analysis software for open-type reverse-flow heat source towerwith C++language.Lastly, a case study was performed with an office building in Chongqing. TheDeST energy simulation software was used to calculate the annual dynamic load of thebuilding. And with the winter energy analysis software for open-type reverse-flow heatsource tower, the office building’s open-type heat source tower heat pump system’sheating performance, operation economy and energy saving performance are discussedby comparing them to that of Air Source Heat Pump system and Gas Boiler system.Results shows that heat source tower heat pump system can save operating cost by5.55%compared to Air Source Heat Pump system. The heat pump unit can save energyby19.04%, and the system save energy by7.29%. Compared to Gas Boiler system, heatsource tower heat pump system can save operating cost by10.73%，and the system cansave energy by28.75%. On this basis, the applicability of heat source tower heat pumpsystem in hot summer and cold winter region has been discussed qualitatively. Andresults shows the system is applicable to hot summer and cold winter region, especiallyin Nanjing, Hefei and their surrounding regions. |
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