Study On Operation Characteristics And Optimal Design Of Solar Energy-Sewage Source Heat Pump Coupled Hot Water System

At present,when non-renewable energy is increasingly scarce,the development and efficient utilization of renewable energy has received extensive attention,and solar energy resources have been paid more attention.However,due to the uneven distribution of solar energy resources in time and space in China,auxiliary heat sources are needed to ensure the stability of heating.The combination of solar energy and sewage source heat pump can give full play to their advantages,which has attracted the attention of scholars at home and abroad.But there are still some deficiencies in the research on the improvement of solar energy utilization efficiency and the optimization of key parameters of the solar-sewage source heat pump coupled hot water system,at the same time,the research of the preparation of solar lowtemperature hot water as the supplementary heat source of heat pump are also study,but did not analyze the specific impact on the performance of the system.So this paper will use the experiment to study the factors that affect the performance of sewage source heat pump,and combined with a university student bathing water project in Jiangsu area,they are carried out that selection of the design,comprehensive benefit analysis,operation characteristic research and key parameter optimization of the solar-sewage source heat pump coupled hot water system hot water system.First of all,the performance of sewage source heat pump unit was studied by experiments.Two working conditions,namely,summer heating mode and winter cooling mode,were selected respectively.The outlet water temperature at the user side and the inlet water temperature at the water side were used as experimental variables to study the influence on the heating capacity,cooling capacity,input power and COP of the sewage source heat pump unit.The analysis results show that the inlet water temperature at the water source side and the outlet water temperature at the user side have different degrees of influence on the heat production,cooling capacity,input power and COP of the unit under the two working conditions.Therefore,in order to ensure the high performance operation of the unit,the temperature at the water source side should not be too low,and the temperature at the user side should not be too high in the heating mode.In the refrigeration mode,the temperature at the water source side should not be too high;The outlet water temperature on the user side should not be too low.Secondly,according to relevant specifications,parameters of the solar-sewage source heat pump coupled hot water system are designed,and TRNSYS is used to establish a simulation model.based on the TRNSYS model,the influence of tap water temperature,water replenishing measures,collector area,volume of collecting water tank,volume of storage tank and heat pump capacity on system performance were studied.The results show that the water temperature effects on the performance of the system,are the factors that cannot be ignored in the simulation,water replenishing measures can effectively improve solar fraction and heatcollecting efficiency of the system on winter,37% and 25% respectively,smaller influence on summer.At the same time,volume of collecting water tank,volume of storage tank,collector area and heat pump capacity also have different degrees of influence on the system performance.Finally,using orthogonal test,taking the annual cost as the evaluation standard,taking the collector area,the volume of the collecting water tank,the volume of the heating water tank and the heat of the heat pump as the optimization factors,the optimal matching scheme of the research system is obtained.And the s comprehensive benefit of the the solar-sewage source heat pump coupled hot water system are analyzed,and the results show that the design cases,the solar-sewage source heat pump coupled hot water system in minimum energy consumption,8.52 tons of standard coal,is a third of the solar + electric heating hot water system,cost value of 299200,compared with the solar + electric heating hot water system can reduce 165600 yuan,At the same time,the solar energy-sewage Source heat pump coupled hot water system has significant environmental benefits.After optimization the annual cost was 40,000 yuan lower than that under the design condition.It can be seen that the optimized design scheme has significant economic and environmental benefits.