System Construction And Operating Property Of The Water Source Gas Engine-driven Heat Pump System

The gas engine-driven heat pump?GEHP?system,uses gas as the direct energy,is a vapor-compression refrigeration plants,which driven by gas engine.The GEHP system,compared with other cooling and heating systems,the GEHP has great advantages:1)recovering the waste heat from the engine;2)showing better part-load performance and is armed with speed adjustment to meet the user's requirement;3)balancing the difference between peak and valley loads of electricity and natural gas.The work of the present work is to evaluate the performance of a water source gas heat pump system in different season and methods of waste heat.Detailed research contents are as follows:The water source gas engine-driven heat pump?WSGEHP?system with R134a was design.The majority of the work included equipment selection,pipelines design and control programming.Experimental research on the performance of WSGEHP system with waste heat recovery from engine and condenser in cooling mode.The cooling capacity,waste heat recovery,gas engine consumption,PER and out temperature of cooling and hot water.The results indicated the PER_1,cooling,PER_2,cooling,cooling capacity,heat recovery,and gas consumption increase by 26.8%,16.1%,40.6%,23.6%and 10.8%,respectively,as the evaporator water inlet temperature varies from 5.9? to 16.3?.The total capacity of WSGHP with the engine and condensing heat recovery is about 35%higher than traditional GEHP system only with the heat recovery from gas engine.And the PER of WSGHP system was between 2.09 and 2.34 under experimental condition.Experimental analysis on the performance of WSGEHP system by using the engine waste heat recovery as an assisted source in heating mode.The low-temperature heating water was heated by condensing heat and engine waste heat.Meanwhile,some factors such as gas engine speed,evaporator water inlet temperature,and condenser water inlet temperature were also emphatically introduced.The effect of the gas engine speed is significant to the performance characteristics of the GEHP system.As the gas engine speed increase from 1200rpm to 1600rpm,the heating capacity,waste heat recovery and gas consumption increased by 12.4%,27.6%,and 25.8%,respectively,but the PER_1,heating,heating and PER_2,heating decreased by 18.6%and 11.3%.Hence,it is reasonable to keep the gas engine functioning at low speed when the demands of users are satisfied.Finally,variations of the cooling/heating capacity,gas consumption,refrigerant flux,and physical parameter of inlet and outlet in compressor of system with different superheat degree in cooling and heating mode.It was found that as superheat degree decreased from 12? from 5?,the PER_1,cooling and PER_2,cooling of system increased 14.9%and 12.2%,respectively.It is easily obtained that using electronic expansion valve to decrease the superheat degree could improve the system performance remarkably.