Theoretical Study On The Ejection-absorption Refrigeration Cycle And The Study On The Boiling Heat Transfer Of R290-oil

As the problem of energy consumption has been more and more serious all over the world,energy conservation and emission reduction become the theme for all industries.In the field of refrigeration,absorption refrigeration techniques have attracted increasing attention in both residential and industrial applications for it can be driven by low-grade energy.In order to solve the problems of miniaturization and air-cooled type for absorption refrigeration system,a type of air-cooled ejection-absorption refrigeration cycle is proposed in this thesis.This thesis builds the mathematical model of the novel cycle and studies the cycle theoretically.The results show that compared to the conditional cycle,the novel ejection-absorption refrigeration cycle has higher COP and lower total heat load.What's more,the cycle can operate normally at wider range of the working condition.Thus,the application of the ejector and the non-adiabatic absorber has great benefit for the improvement of COP and the miniaturization of the system.The application feasibility of R290-oil is researched in this thesis.The results show that COP of the R290-oil ejection-absorption refrigeration cycle can reach as high as 0.5297.R290-oil is a kind of ideal working pairs.Besides,this thesis also studies on the flow boiling heat transfer and pressure drop characteristics of R290-oil in horizontal tubes.The results show that under the test conditions,the flow boiling heat transfer coefficients of R290-oil is in the range of 1100-2100 W?m^-2?K^-1 and the pressure drop is in the range of 4-9 kPa.The flow boiling heat transfer coefficients increase with the decrease of the tube diameter and fluctuate with the increasing heat flux.Mass flow rate and vapor quality has little influence on the flow boiling heat transfer coefficients.And five kinds of correlations are chosen to predict the experimental results.The results show that the correlation of Gungor and Winterton has the highest precision with a mean deviation of±15.75%.The research of this thesis is meaning for the design and the application of air-cooled absorption refrigeration system.