Simulation, Optimization And Experimental Testification Of Air-source Gas Engine-Driven Heat Pump

Gas engine-driven heat pump (GEHP) is a kind of novel heating and air-conditioning equipment that is high efficient, energy saving, economical and environment-friendly. Researches on GEHP are still on the launch in China. This dissertation investigates the air source GEHP both experimentally and theoretically. The main contents are as follows:Aimed at the air source GEHP, a mathematical model has been made. It is made up of sub-models of the engine, compressor, plate evaporator, plate condenser, fin and tube evpoarator, fin and tube condenser, electronic expansion valve, four-way valve, accumulator, seperator, plate-fin exhaust gas heat exchanger. An air source GEHP test rig has been set up. Data measured on the test rig and from relative literatures are used to testify the GEHP model and sub-models. The minimum difference selection method among different heat transfer and friction correlations in heat exchangers has been put forward. The compressor model has taken the superheat, sub-cooling temperature and rotary speed correction into account. The fin and tube heat exchanger model has been built on the basis of single tube model, and it can simulate those heat exchangers with complex tube arrangements.Based on the simulation model, optimal matching between engine and compressor, GEHP system optimization and heating load factor have been studied. Method of drive ratio definition according to the actual whole year maximum load has been brought forward. Aimed at the weakness of single drive ratio connection on the load modulation performance and the partial load performance, the multilevel drive ratio connection between engine and compressor has been investigated. It proves theoretically that the multilevel drive ratio connection can improve the engine operation conditions, the load modulation performance and the partial load performance, increase the PER and annual operation performance of GEHP. The single operation optimization model with the PER as the objection and the total heat exchanger fee as a restriction has been set up. Considered the variable-speed operation characteristic of GEHP, the idea of the whole year performance optimization has been put forward, with the whole year PER (APER) as the objection. Analysis and comparison between the whole year optimization and the single operation optimization have been done. The thermo-economic optimization model has been made to study the heating load factor of GEHP.The heat balance of gas engine has been calculated theoretically with the above GEHP model. And two different ways of waste heat recovery have been studied mathematically.With the experimental and computer simulation as the investigation tools, the optimization and matching of the GEHP have been studied. The methods and conclusions can be referred in the GEHP research and design.