Application Research Of Solar Assisted Air Source Heat Pump System For Office Buildings Of The Rural And Township Area In Severe Cold Regions

The application of the new heating system is of great strategic significance for the upgrading of the traditional heating mode in the severe cold area.Solar assisted air source heat pump system?SAHP?is a clean and stable heating form,which combines solar energy utilization and air source heat pump technology organically,and uses two kinds of low-level energy,solar energy and air at the same time.In this paper,aiming at the village and town public buildings in the severe cold area and making full use of the abundant solar energy resources in Xinjiang,the simulation analysis and experimental research are carried out around the system composition,control mode,operation characteristics,system benefits and other factors of the SAHP proposed in this paper,which provides a theoretical basis for the upgrading of the village and town heating mode in the severe cold area And data support.Firstly,based on the two aspects of system composition and local equipment,the SAHP system is initially constructed.The equipment is equipped with 6 flat solar collector plates of 2.25 m² for solar cells;one heat pump unit with rated power of 4.2 kW and type of rsv-12a is selected for air source heat pump unit;0.5 m³ cylinder heat preservation water tank with dimension of?700×2137mm is selected for heat storage water tank unit;and the nominal diameter of floor panel radiation heating unit is 15 Mm cross-linked polyethylene?PE-X?pipe,and choose a denser 150 mm coil spacing.At the same time,the automatic control system of the composite heating system is designed based on the requirements of the start and stop conditions,data transmission mode,programming principle and other aspects of the operation of each unit of the SAHP system.Secondly,the mathematical model of the SAHP system is established,the operation characteristics of the solar collector unit and the air source heat pump unit of the composite heating system are analyzed,and a simulation calculation method of the operation of the composite heating system is given,which provides a theoretical basis for the test operation control;the simulation results show that the maximum heat consumption of the test room before the transformation is 357.30 MJ·d^-1,and the average value is 197.96MJ·d^-1,the maximum heat consumption of the transformed test room is 232.45 MJ·d^-1,the average value is130.39 MJ·d^-1,and the heat load after the transformation is only 65.87%of that before the transformation;the daily heat collection trend of the solar collector during the heating period is calculated,the average heat collection of the solar collector is 36.04 MJ·d^-1,and the total power consumption of the whole heating eriod is expected to be 2673.25 kW·h.Then,the experimental results show that the solar collector has a heat collection capacity of 31.15 J·d^-1.In the cold transition period?including October,November,March and April?,it undertakes most of the heat supply of the heating room,and the solar energy utilization rate can reach more than 80%.In the severe cold period including December,January and February,more than 70%of the heating consumption needs to be provided by the air source heat pump system,and there is a good linear relationship between he system cop and the ambient temperature in the temperature range of-25?to 15?.After comparing the test results with the simulation results,the simulation results fit well.Finally,it analyzes the SAHP system from three aspects of comfort,economy and energy saving.Compared with the traditional coal-fired boiler,the solar energy combined air source heat pump composite heating system is conducive to improving the thermal comfort of the building.In terms of economy,the ayback period of the solar energy combined air source heat pump composite heating system is 9.8 years,and the composite heating system has a lot of room to improve,and the low price of coal is still the bstacle to the promotion of the new system.The energy-saving benefits of the composite heating system are significant.In one heating period,the emission reduction of CO₂ is 149.10 kg/m²,the emission eduction of NO_x is 4.49 kg/m²,and the emission reduction of SO₂ is 2.24 kg/m²,which can effectively educe the indoor air pollution and contribute to the energy-saving and emission reduction work in the cold area of Xinjiang.