Experimental Study Of An R290 Split-type Air Conditioner Using A Falling Film Condenser

According to the "Montreal Protocol" Kigali amendment classified HFCs as greenhouse gases and clarified their reduction schedule,the refrigerant replacement for split-type air conditioner is extremely urgent.R290 becomes the most promising refrigerants for split-type air conditioners(STAC)because of its excellent environmental and thermodynamic properties.However,R290 has flammability,it presents a potential fire risk.There is necessary to redesign STAC to reduce the refrigerant charge for the safety use.Many studies show that more than half of the refrigerant in air conditioner system was trapped in the condenser.This indicates that efforts should first be made to substantially reduce the refrigerant hold-up in the condenser.This work uses a mathematical model to analysis the characteristics of refrigerant hold-up in the condenser,and then proposes a novel falling film condensing technology to address this problem.In the early stage of the experiment,a series of work on structure optimization has been carried out to improve the heat transfer performance of the falling film condenser.Lastly,the novel condenser was setup on a STAC and tested in the standard psychrometric chamber.Experimental results show that using falling film condenser significantly reduces the refrigerant charge.The required refrigerant charge was reduced 27.5% to only 290 g.The cooling capacity and COP of the novel system were 2690 W and 3.55,which were 0.98% and 5.97% higher than the corresponding value in the original air conditioner system,respectively.The R290 STAC meets the energy efficiency and safety requirements.The falling film condenser provides a new technical route for the application of R290 STAC.