The Studying of the Operation Mode of the Solar-Air Dual-Source Heat Pump
|School||Zhongyuan Institute of Technology|
|Course||Heating,Gas Supply, Ventilation and Air Conditioning Engineering|
|Keywords||Solar - air source Composite heat source Dual - source heat pump Mathematical simulation Run mode|
The heat pump technology as a new energy technologies, energy conservation, environmental protection have made outstanding contributions to widespread attention in recent years worldwide. When the surface temperature of the heat pump outdoor heat exchanger is lower than 0 ° C and less than the air dew point temperature, the surface will frost greatly decreased, so that the performance and reliability of the heat pump heating. This group proposed solar - air composite heat pump system with two heat sources. The system is able to utilize both solar energy and air low energy, to reduce the influence of season and the outdoor temperature on the system performance, and can improve the stability of the system. The system will convert the solar thermal technology and air source heat pump technology to be fully integrated to achieve part of the construction at a reasonable cost to meet energy demand, and thus it is as a building energy-saving technologies will have broad market. On the basis of previous studies to further improve and optimize this system simulation model, the establishment of a working fluid system (including refrigerant, glycol solution and air) thermal parameters of the mathematical model, the mathematical model of the compressor, capillary mathematical model using distribution parameters Law and establish condenser mathematical model, the mathematical model of the evaporator. Using numerical simulation of three heating solar - air composite heat pump system with two heat sources operating modes: a single air source mode, solar - air dual-source model, a single solar hot water mode. Simulated solar - air heat pump system of dual heat source composite system characteristics under different operating modes, to arrive at the best operating mode of the system in different conditions. The simulation results and experimental results of the previous research group comparative analysis, the error is less than 10%, reduced previous simulation error with respect to the research group, the simulation results for this new type of solar energy - air composite heat pump system with two heat sources The optimization and design provides a theoretical basis. The simulation results show that the factors closely related to solar - air dual heat source composite heat pump system with the outdoor temperature, solar hot water, water temperature and solar hot water flow. Single air source heat capacity of the model system and the system COP increases with increasing outdoor temperature, single solar mode of heating capacity and system COP with solar hot water inlet temperature and solar hot water flow rate increases with increasing dual-source model in the range of effective composite temperature difference, the heat capacity of the system and the system COP increases with the rise of the outdoor temperature and solar hot water inlet temperature and solar hot water flow increases. Simulation conditions, solar - air dual heat source mode and the mode of a single solar system heating capacity and COP of the system is higher than the effective composite temperature difference within the system heating capacity and system COP of a single air source mode. The dual-source model compared to a single air source heating capacity increased by 2.8% to 46.5% the system COP increased by 1.1% to 34%. Single solar mode compared to a single air source heating capacity increased by 1.2% to 92.8% the system COP increased by 1.8% to 62.8%. When the outdoor air temperature is higher than -5 ° C, the effective composite temperature difference range within the solar - air heat source composite heat pump heating capacity relative to single solar mode can be increased by 20.4%, the system COP decreased by 1.11% to 8.5%, so when the outdoor air temperature is higher than -5 ° C, if the user is the heating capacity of the first demand preferred dual-source model, users of heating capacity decreases, preferred a single solar mode. When the outdoor air temperature is below -5 ° C, the effective composite temperature difference range within the solar - air heat source composite heat pump heating capacity relative to single solar mode increased by 0.8% to 17.3%, the system COP reduced by at least 3.2% to 14.3%, when the outdoor air temperature is below -5 ° C, if the solar adequate preferred single solar mode, if the solar energy is not sufficient, then the preferred dual-source model. Rated cooling conditions, the system cooling capacity of 2360W, the energy efficiency ratio of 2.6, below the air-conditioning energy consumption standard 3.2, then presents a system improvement program.