Research On The Application Of Direct-expansion Solar/Air-assisted Heat Pump In Rural Building

With the development of social economy,China’s energy consumption is increasing gradually.Make our country energy situation faces severe challenge.In recent years,with the development of solar energy and the requirement of building energy conservation,as well as the development of cities and the improvement of people’s living standards,"integration of solar energy and building" and "all-weather heating" have become important topics of solar energy utilization in China.Evaporator of the air source heat pump absorbs heat from a single heat source under heating conditions in rural buildings.To this end,a new direct-expansion solar/air-assised heat pump that can absorb solar energy and air energy simultaneously is proposed.By integrating solar collector and heat pump evaporator into one,the effect of heat extraction from multiple heat sources can be achieved under heating conditions.To verify the superior or inferior heating performance of the new direct-expansion solar/air-assised heat pump in rural buildings,a practical test platform of the new direct-expansion solar/air-assised heat pump system was set up in Handan.During the period from February26 to March 2,five days of practical tests were conducted in a rural building of a radiant floor heating user.The tests analyzed outdoor temperature,solar radiation intensity,system heat production,power consumption,COP and indoor temperature variation.Software Sketch Up was used to build a detailed geometric model for the typical rural building,and the building parameters were imported into software Trnbuild for time-by-time energy consumption simulation during the heating season,as ways to understand the energy consumption of the typical rural building during a heating season.In order to compare the operating performance and heating effect of the direct-expansion solar/air-assised heat pump system and the air source heat pump system in a heating season.Based on the establishment of the new direct-expansion solar/air-assised heat pump module TYPE200,two simulation systems for heat pump units were established through TRNSYS software.The heating capacity,power consumption,COP value,heat collection efficiency of the heat collector evaporator,indoor temperature,PMV and PPD and other operating parameters of the two systems in a heating season are compared and analyzed.The correctness of the model is verified by comparing the experimental data with the simulation results.To achieve better operation effects,the collector evaporator’sinclination angle,azimuth angle and the volume of the hot water storage tank of the unit are optimized with the help of the Gen Opt software.Finally,in order to find the most reasonable operation mode of the system,the economy and environmental protection of the direct-expansion solar/air-assisted heat pump system and air source heat pump system are analyzed.This research topic provides a new application module for TRNSYS software.By comparing and analyzing the heating performance and operating effects of the two systems in a heating season,it highlights the superiority of the direct-expansion solar/air-assisted heat pump system in the heating effect of rural areas,and solves the common problems of heating in rural areas.It provides a theoretical basis for the promotion of clean energy heating renovation in rural areas.