| The cold wet weather in hot-summer and cold-winter zone leads to the result that there is not an efficient solutions on the issue of air-conditioning and sanitary hot water in winter.At present,there are two ways to solve the questions: first,to adopt air-source heat pump,but the high humidity weather makes the evaporator easy to frost,so electric-heating or reverse-cycle are necessary to make air-source heat pump improve efficiency.But in extreme weather,it is necessary to adopt electric heating,and it may cause serious energy consumption.And the second method is burning fossil fuels,but it releases carbon dioxide which cause environment pollution.The application of water source heat pump system has perfectly solved the two problems above,and it will not frost in winter.The operation of water source heat pump only requires a small amount of electric energy and higher energy efficiency,which can effectively reduce the use of fossil energy,and it plays a important role in the protection of the environment and purification of air.By participating in the compilation of "The Comprehensive Utilization and Development Program of Water Source Heat Pump in Changsha",the author was involved with all aspects of the research and analysis about the application of surface water source heat pump in hot-summer and cold-winter area.Firstly,it summarizes the research status for surface water source heat pump at home and abroad,illustrated that the utilization mode of surface water source heat pump system and the demand of water source and the influence of environment.It put forward that surface water can be a criteria to estimate in the surface water source heat pump should be easy to get,quantity sufficient,temperature stable and quality good and with a clear seasonal fluctuating of water level.In addition,adopting proper water intake methods,and using the water body correctly when preventing thermal pollution.Secondly,it puts forward the calculation method of cold and heat carrying capacity of stagnant water in water source heat pump to combine the cold and heat carrying capacity and running time with the cold and heat carrying capacity of water body.By the research and summary,it established a model of water temperature which based on stagnant water body,and compiles the simulation program to make a solution and verification.It also showed that the variation of water temperature of stagnant water body in Hunan area,analyzed the heat transfer and calculates the heat carrying capacity of stagnant water in Hunan,which is a typical hot-summer and cold-winter zone.A detailed study on stagnant water body was made in Changsha,which was a typical city in hot-summer and cold-winter zone,calculated the heat carrying capacity of 14 stagnant water bodies in metropolitan area.And combined with the cold and heat carrying capacity of buildings and the operating time of units.By comparing the calculated and measured results,the heat transfer between the surface water and the environment was able to calculate by means of the effective method and proposed in this study,which may reflect the real heat exchange conditions.As the heat transfer mainly conducts through the surface water,the meteorological environment of the water surface may directly affect the heat transfer capacity of the water body.It finds that the heat carrying capacity of the water body will increase with increasing depth of the water body.The judging standard of the water body is rotated,which is not positive correlation.Therefore,it is complex to study the variation of hot bearing capacity of lake waters with the depth of the water body,which needs a further study on it.In summer,the solar short-wave radiation and the long-wave heat transfer between the water body and the surrounding environment make a great influence on the heat carrying capacity,and the minimal influence is the heat transfer in soil,while it is the heat flux between the water body and the surrounding air in winter.When the depth of water below 2 meters,the cold and heat carrying capacity is lower,and the comprehensive heat and cold bearing capacity is limited under the meteorological conditions in Hunan province.Thirdly,by studying utilization potentiality and influence factor of river WSHP,this thesis came up with a computing method to test its cold and heat carrying capacity.After investigating the situation of river water sources in Changsha,a typical city in hot-summer and cold-winter zone,this thesis predicates its cold and heat carrying capacity and the application of river WSHP.By comparing the calculated results with the measured results,it calculated that the heat transfer between the river water and the environment by the method proposed in this paper,which reflected that the heat transfer of the actual water body.It’s worth nothing that water body is the heat difference between the two interfaces that determines the heat carrying capacity of the river.Therefore,meteorological environment of the water surface and the water flow both affect the heat transfer capacity of the water body.Finally,through the methods of transporting water from the surface water source heat pump system to buildings directly for focus utilization and setting heat pump system in each building for disperse utilization,this thesis optimized the pipeline system of WSHP utilization.By studying the use pattern of WSHP and the requirements of water source,this thesis established an economical mathematical model of WSHP energy and water station.Based on analysis of examples and on comparison of initial cost,operating cost and life cycle,the thesis concluded the optimal site-selection scheme.The user friendly location of energy station would be more rational considered from economic perspective if there was no other limitations.The thesis composed a new extensive method of WSHP — water station utilization.It possesses better economical efficiency compared with initial cost,annual operation cost and life cycle.The thesis analyzed different choice of WSHP system utilization methods under different loading conditions.From the analysis of LCC,energy station’s LCC would be more rational while the cold load of energy centre is over 1000 kw.In contrast the water station would be better.With changeable distance from intake points to energy utilization center,200 m to 2600 m makes less total cost of water station utilization method.Thus water station will be more economic and reasonable. |
PDF Full Text Request