Study On Air Source Heat Pump Assisted Solar Water Heating System In University Dormitory In Jinan

Under the dual pressure of the increasing tension of conventional energy and environmental pollution,solar energy,as a clean renewable energy,has become a new hot spot in the field of international energy development and utilization.The energy consumption of domestic hot water can account for about 10%¹5%of the building energy consumption.Making full use of solar energy to prepare domestic hot water can greatly save the use of fossil fuel.However,due to the intermittence and instability of solar energy,the solar hot water system needs to be equipped with auxiliary heat sources to ensure the stability of water supply.Air source heat pump assisted solar hot water system can develop advantages and avoid disadvantages,and can produce domestic hot water with high efficiency and energy saving.Taking a solar hot water system of a university in Jinan as an example,the actual operation data of the project is analyzed in this paper,and the energy-saving effect of different optimization strategies is simulated and evaluated by TRNSYS software.The research results provide reference for the optimal design and energy-saving transformation of the solar hot water system in Jinan.Specific research contents include:?1?The actual operation data of a solar hot water project in a University of Jinan from September 20 to December 31 is analyzes in this paper,analyzes the water consumption,typical daily operation parameters and system energy consumption of the project.The results show that the average daily water consumption of female apartment buildings is more than that of male apartment buildings.,Hot water consumption of the system gradually increases from September to December,the peak period of water consumption of student apartment buildings is 20:00 to 22:00,and there is basically no water demand from 23:00 to 7:00 of the next day;the power consumption of the system is related to water consumption and weather conditions?ambient temperature,solar irradiance?.The energy consumption per unit of hot water in the period is 11.63kWh/t,the lowest one of 2.4kWh/t in September,and the highest one of 15.46kWh/t.in December.?2?The single tank simulation model of air source heat pump assisted solar water heating system is established by TRNSYS software.Based on the typical meteorological data of Jinan City,the simulation of the system is carried out under the current operation conditions,and the annual operation characteristics of the system are quantitatively analyzed.The simulation results show that the total annual power consumption of the hot water system is 32735.41kWh,in which the power consumption of air source heat pump accounts for 88.63%,the annual average heat collection efficiency of the collector is 0.47,the annual solar energy guarantee rate is 0.70,and the annual average COP of the system is 11.62.?3?TRNSYS software is used to simulate the optimization measures of the hot water system.Through the simulation results,the operation characteristics and energy-saving effects of different optimization measures are analyzed.The optimization measures include the optimization of the start and stop temperature and operation time of the heat pump,the optimization of the volume of the water tank,the different water use modes,the thickness of the water tank insulation,and the comparison between the single water tank and the double water tank.The simulation results show that the system is still relatively good Large energy-saving space,taking appropriate energy-saving measures can reduce the energy consumption of hot water system;on the basis of the above research,combined optimization simulation analysis is carried out for the system,the combined optimization scheme is:double water tank system,the volume of both water tanks is 16t,the insulation thickness is 50mm,the heat pump operates all day,the start and stop temperature is 42/47?,and other parameters are consistent with the single water tank system.The simulation results show that the heat collection efficiency,solar energy guarantee rate and COP of the system are all improved by using the optimized scheme.The heat collection efficiency is increased from 0.47 to 0.53,the solar energy guarantee rate is increased from 0.71 to 0.83,the cop of the hot water system is increased from 9.94 to 11.51,and the annual power consumption is reduced by25.06%.The optimized scheme can achieve better energy saving effect.?4?According to the software simulation results,the economic and environmental benefits of the hot water system are analyzed.The results show that the annual conventional energy substitution before and after optimization is 35.92tce and 41.02tce respectively,the annual operation cost saving before and after optimization is 119598 yuan and 136417 yuan respectively,and the investment recovery period before and after optimization is 5.54 years and 4.83 years respectively;the system can reduce 88.72t CO₂ emission and 718.4kg SO₂emission before optimization,After optimization,the emission of CO₂,SO₂ and dust can be reduced by 101.32t,820.4kg and 410.2kg respectively.