Research On The Mode Selection Of Ground-Source Sides Of Solar Groud-Source Heat Pum Air Conditioning System

In this paper,the researching object of this study is the of solar-ground source heat pump air conditioning system in Hebei University of Technology,which has two ground source heat pump units(HP1 and HP2)with different heat capacities corresponding to two groups of boreholes heat exchanger(pipe group 1 and pipe group 2).The current operation of the dual solar energy-ground source heat pump system(HSGSHP-I system)is independent mode of the ground source side.Through the analysis of the actual running situation from 2012 year to 2015 year,that large units(HP1)the average load rate is 57%,the load rate is low,and with the increase of HP1 for the thermal load,the unit COP increases;heat storage utilization rate is 43%,the corresponding HP1 buried pipe group(pipe group 1)soil average temperature than the corresponding HP2 buried pipe group(pipe group 2)the soil average temperature low 7.13?,pipe group 2 heat storage space available.Based on HSGSHP-I system,in order to improve the unit part load rate,heat storage utilization and evaporator inlet temperature,put forward the two buried pipe group are connected to the large units at the same time and achieved the purpose of two underground pipe group at the same time to provide heat to the evaporator unit of large unit in the heating season,and then put forward two new system ground source side coupling system,the interconnection of double unit HSGSHP system(HSGSHP-II system)and single unit HSGSHP system(HSGSHP-III system).Using TRNSYS software to establish three different ground source side coupling mode of solar ground source heat pump simulation model,based on the actual operation in 2014 and 2015 to verify the accuracy of the simulation module,the relative error of model heat capacity,power consumption,heat capacity,heat storage capacity and the actual result is less than 5%.By using the simulation model,simulation and prediction for a period of 20 years and a heating season run on three kinds of ground source side coupling system,from the performance,stability and economy of the three aspects of the analysis,the results show that the ground source side interconnection double unit system running the lowest energy consumption and running performance optimum,operation cost of a double unit system ground source side independent savings of 7.3% in a heating season,but the highest additional investment,economic advantage is not obvious.The single unit ground source side interconnection system efficiency is best,an average of a heating season than the ground source side independent of each other to save 10124 yuan,but in a very low load period,running performance is poor,is more suitable for extremely low load or low load ratio is very low buildings.The coupling system of thermal storage ground source side interconnection utilization rate can be increased by about 20%,effectively reduce the storage of the heat pipe group heat accumulation and heat fee,unit part load rate can be increased by 3%-13%,can improve the evaporator inlet temperature,so as to improve the unit performance in different level,make the system efficient operation for a long time.