Application Analysis And Experiment Research Of Solar Energy And Ground Source Heat Pump Composite System

With the development of technology and economic globalization, energy andenvironmental issues have become the focus of people’s attention, thus energy savingand environmental protection has become the theme of today’s world. Ground sourceheat pump (GSHP) technology, as a new technology for renewable energy use inHeating, Ventilation and Air Conditioning Engineering (HVAC), have been widelynoted. The advantage of GSHP lies in its high energy efficiency. However, theimbalance between cooling and heating load for summer and winter in some areaswill change the underground temperature, resulting in the decrease of system’s energyefficiency ratio (EER), which has been the major "bottleneck" of restricting the GSHPtechnology’s popularization and application. Currently, ground source combining withother cold heat sources heat pump systems have become one of the hot research topicsin the country or abroad. In order to expand the application of GSHP systems, in thispaper, the way of a combination of solar energy and underground source is adopted tobuild composite heat pump system, and its associated performance were studied.In this paper, use TRNSYS software to establish solar system and ground sourceheat pump system simulation model,and the test is based on the Solar system test anda ground-source heat pump system of a building in Tianjin, apply the actual testeddata to validate the accuracy of the simulation model. Meanwhile, use TRNSYSsoftware to simulate and analyze the hourly load of the building throughout the year,get that the maximum of instantaneous heat load of the building occurs in mid to lateJanuary annually. The maximum of instantaneous cooling load appears in mid to earlyJuly annually.Then establish a solar energy combining with GSHP system’s simulation model,based on the study of GSHP system’s performance ever before, to analyze complexsystem’s performance in series mode and parallel mode. When the composite systemconnected in series, the mean co-efficiency of performance (COP) of units connectedin two different modes of solar collectors and underground pipes are respectively4.29and4.35; when the composite system is connected in parallel, Pr has an impact onsystem’s performance. When Pr is0.6, the COP value of units is4.27. The COPvalues of complex systems in series in two modes are respectively increased by2.88%and4.31%than a single heat pump system units’ COP of4.17, parallel compoundsystem units’ COP value increased by1.91%than a single heat pump system units’.The results showed that the COP value in the mode of ground source side circulating water flowing through the underground pipes firstly then flowing through thecollector can reach4.35, increased by4.31%than a single heat pump system.Therefore, this approach is the best connectivity solutions for a complex system.Finally, The results of this study show that the solar energy and ground sourceheat pump composite system has an obvious advantage in the north cold area. Thissystem can remedy the destruction of soil temperature field effectively, overcome therestrictions of day and night, seasons and some other natural conditions to solarradiation.In a word, this complex system should be widely applied in the north coldregions.