Research On Heat Pump System Of Heat Source Tower Based On Low Temperature Multi-effect Distillation Regeneration

The Air Source Heat Pump(ASHP)is an environmentally friendly energy-saving equipment that uses high-level energy to transfer heat from a low-level heat source to a high-level heat source.The low-level heat source is the air in the environment,which is clean,can be reused,and does not Inexhaustible features.However,in winter operating conditions,the surface of the outdoor heat exchanger of the air source heat pump is prone to frost,which leads to a linear decline in the heating performance of the heat pump.The heat source tower heat pump can effectively solve the problem of frosting on the surface of the outdoor heat exchanger.However,with the operation of the system,the freezing point of the antifreeze solution in the heat source tower gradually rises,so It needs to be concentrated to reduce the impact on the heat pump system.In this paper,by comparing a variety of solution regeneration and concentration methods,a heat source tower heat pump system(multi-effect regenerative heat pump system)based on Low Temperature Multi Effect Distillation(LT-MED)regeneration is proposed and studied.This article introduces the main modules of Aspen Plus and establishes the corresponding mathematical model,uses Aspen Plus to establish a flowchart corresponding to the literature,and performs simulation calculations under the same operating conditions,and compares and analyzes the simulated values with the literature values.Verify the accuracy of Aspen Plus process simulation.In order to determine the structure form of the multi-effect distillation system(feeding method,effect number,presence or absence of condensate flashing),the calculation and analysis are carried out,and the conclusion is drawn that the regeneration performance of the multi-effect distillation system and the heat exchange temperature difference are considered comprehensively.The downstream three-effect,non-condensed water flashing structure is used to study the multi-effect regenerative heat pump system.This paper establishes the Aspen Plus flow chart of the multi-effect regenerative heat pump system,and analyzes the operating parameters(first-effect cycle rate,evaporation/condensing temperature,design latent heat ratio,solution freezing point and type)to the ratio of water production,the temperature difference between effects,and regeneration.COP,regeneration loss coefficient and other system performance indicators.The analysis results show that: considering the regeneration performance and heat exchange temperature difference factors,the three-effect non-condensing water flashing multi-effect distillation system structure is more suitable for heat source tower heat pump antifreeze regeneration;the regeneration loss coefficient of the multi-effect regenerative heat pump system under regeneration conditions Concentrated at about 5%,it is slightly affected by the evaporation temperature,condensation temperature,design latent heat ratio,freezing point of the solution and types,indicating that the multi-effect regenerative heat pump system proposed in this paper has stable climate adaptability.The exergy analysis and optimization of the multi-effect regenerative heat pump system are carried out,and the result is that the feed solution is gradually preheated to reduce the exergy loss;when the latent heat ratio is 20%,the multi-effect regenerative heat pump system is designed by changing the feed There is no room for optimization of the multi-effect regenerative heat pump system for the mass flow of the solution and the first-effect circulating solution.This paper uses Aspen Plus to perform process simulation calculations,determines the structure of the multi-effect distillation system,and calculates and analyzes some of the operating parameters of the multi-effect regenerative heat pump system.The results of the feasibility of the multi-effect regenerative heat pump system are obtained,and the heat source is further promoted.The use of tower heat pumps provides new ideas and theoretical foundations.