| The energy efficiency of air source heat pump used to be very low under severe cold conditions,and it also has the problem of frost formation.Performance of a simple solar heating system may fluctuate heavily due to the weather.If combined them together,the shortcomings of them can be compensated to some extent.In order to solve the intermittence of the solar energy,it might be a nice choice to store excess solar energy by making hot water at the same time.In this paper,this principle is focused on to carry out related works.In this paper,a mixed-type indirect expansion solar heat pump system is presented.In order to meet the demand of the room heating,and provide heating water at the same time,five working modes and the control mode of the system are designed according to different weather conditions.This system uses the air collector to heat the air and send it into the room when the weather is fine in the day time,or uses the air source heat pump for room heating.When the temperature is very low in the day time,the system uses the air which heated by the air collector as the heat source of the heat pump for room heating.In general,the system uses the air source heat pump for room heating.When the temperature is very low at night,it can send the hot water stored in the tank to the room for heating,or uses the hot water as the heat source of the heat pump for room heating.In this paper,the physical model and mathematical model of the system are established,and the parameters of each component are also determined.The meteorological parameters in middle and lower reaches of Yangtze River Basin are selected for the simulation of the system operation in the whole heating season.The daily and monthly operating parameters of each heating mode and hot water supply mode are obtained.The simulation results show that the average monthly energy efficiency of the system for room heating ranges from 5.1 to 6.7,which shows good performance of the system.The average monthly heating capacity is between 1754 to 2351KW?h,which is able to meet to the demand of the room heating.The monthly hot water quality of the system ranges from 14335 to 22045 Kg,and the energy efficiency in producing hot water ranges from 2.6 to 13,which also shows good performance of the system.According to the designed system,choosing the combination of air collector and air source heat pump,the combination of water collector and air source heat pump to carry on the experiment in one day.Experimental results show that the energy efficiency of the system for room heating ranges from 4 to 7,which is consistent with the simulation results. |
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