Experimental Research On Water-free Heating System With Solar Energy Air-Source Heat Pump

In recent years, the rapid consumption of fossil energy has facilitated the rapid social and economic development, but at the same time caused serious environmental pollution. As a clean and sustainable energy, solar energy is being noticed by more and more country. As Lanzhou region is characterized by long winter period, high consumption of conventional energy and rich solar energy resources, this paper proposes a new solar heat pump water-free heating system, which properly combines the comfort of direct radiant floor heating, the high efficiency of air-source heat pump and the energy-saving property of solar heat pump.In the winter of Lanzhou region, the outdoor temperature and humidity is low, however, the solar radiation is high, this paper first elaborates the basic principles of solar heat pump water-free heating system and analyzes its theory, then designs the components of the system and build the experimental room, finally conduct experimental study on the performance of solar heat pump water-free heating system and calculates the economy and comprehensive thermal performance of the system. The feasibility of the new solar heat pump system in Lanzhou region is analyzed according to the data obtained through experiments and calculations. The main research steps and results are as follows:1、Propose a new solar heat pump water-free heating system by comparing various solar heat pump systems, explain the basic principle of the system and analyze its theory.2、Establish models for various components of the system, build a solar heat pump water-free heating system experimental room as per heating specifications for buildings in Lanzhou region, and commission the system.3、Study the performance of heat pump compressor, ground heating coil, solar collectors and the entire system according to the variation relationship between the amount of solar radiation, solar collectors heat and outdoor temperature, and verify the feasibility of the system in the winter of Lanzhou region, and compare the new syetem with the conventional heating systems in terms of performance.4、Evaluate the comprehensive thermal performance of the solar heat pump water-free heating system in terms of the heat efficiency and exergy efficiency, and compare with other conventional heating systems in terms of comprehensive thermal performance. Evaluate the the economy of solar heat pump water-free heating system, gas-fired system and central air heating system in terms of annual cost.The experiments conclude that the solar heat pump water-free heating system is applicable in Lanzhou region of Gansu province and enjoys the high performance, the average COP of the system increases with the outdoor temperature and radiation during operation, with an average COP of 3.4 in sunny days, an average COP of 2.6 in cloudy days and an average COP of 3.1 in snowy days. When the outdoor temperature is 8 ℃, the maximum COP of 4.2 can be achieved. The system is also economical, with higher initial investment, but relatively low operation cost. The system also has a significant effect on environmental protection, energy conservation and other aspects.