Experiment On Absorption Refrigeration Performance And Its Enhancement With Ionic Liquid As The Working Fluids

Absorption heat pump unit is a kind of energy saving and waste heat recovery e quipment that is widely used in industry,it can turn the low temperature heat source that human can't directly use into the high temperature heat source that can be directl y used.The performance of absorption heat pump have a great relationship with the working medium solution.The traditional heat pump working medium that widely use d now still have many defects in the performance.H2O-Li Br working medium has goo d performance of absorption and is cheaply obtained,but it has very serious corrosion for metal,and can produce crystal that caused devices congestion in the working pro cess.NH3-H2 O working medium is friendly to the environment,but it is also flamma ble,explosive,toxic and harmful,these characteristics make it a big risk in use.So,t o develop a new working medium that develop the advantage of traditional working medium,and improve its shortcomings,has the extremely significant significance for t he improvement of absorption heat pump technology and improvement.Ionic liquid has perfect thermodynamic properties of wide fluid routine,low vapor press ure,less volatile and strong absorptive capacity,and there is no possibility of crystallization a nd equipment corrosion,it is a kind of green solvent that are environmental friendly,and it i s the ideal heat pump working medium.The experiments take ionic liquid [EMIM] + H2O(D EP)as a new medium of solution,and through the absorption refrigerating experiments,we ca rried out in-depth research,analysis and discussion for the refrigeration effectin of this new m edium.(1)According to the literature and data,the device is set up for absorption refrige rating experiments in the laboratory.Ionic liquids are synthesized as new heat pump working medium in the laboratory.The air tightness test and calibration of pressure a nd temperature is conducted for the absorption refrigeration experimental device.(2)Under different circulating water temperature and generating temperature condi tions,the absorption refrigerating experiments are conducted respectively,the total heat transfer coefficient and refrigeration coefficient under different working conditions are calculated.After analysis of absorption refrigeration experimental data we found that:when the temperature of the circulating water is constant,in a certain range,the hig her the generating temperature is,the higher the total heat transfer coefficient of the a bsorber and the refrigeration coefficient values are.When the generating temperature isconstant,in a certain range,the lower the temperature of cooling water is,the greate r the refrigeration coefficient and the total heat transfer coefficient of the absorber are.(3)Lithium bromide is added to the solution of ionic liquid working medium,and absorption refrigeration performance improved experiments are conducted respectively.From the analysis of experimental data,we know that the refrigeration capacity of th e ternary system is stronger than the original ionic liquid binary system.(4)The saturation vapor pressure of the three-system system was determined by st atic method,and the vapor pressure of the tri-element system was reduced by the add ition of lithium bromide,which was favorable for absorption.The higher the lithium b romide content,the lower the system saturation vapor pressure.