Application Of Hollow Fiber Membrane In Absorber Of Open Absorption Heat Pump

China's energy structure is mainly coal,although the use of coal in recent years has declined but still accounts for more than 60%of China's energy consumption,coal will be the main form of energy in a long period of time in the future.The use of coal covers the production links of power generation,heating and other industries.The huge consumption of coal and water resources and pollution emissions make coal-fired boilers one of the key points of water saving and emission reduction.The temperature of flue gas from coal-fired boilers after desulfurization is about45⁶0?,and the moisture content is close to saturation.The flue gas contains abundant waste heat resources and water resources.Recovering this part of flue gas waste heat resources by effective technical means can greatly improve the efficiency of energy utilization and reduce the water consumption of desulfurization equipment.Based on the characteristics of hollow fiber membrane materials and solution dehumidification technology,a set of open-type absorption heat pump waste heat recovery system with membrane absorber is proposed.The size of membrane absorber is optimized by numerical means,and the performance of membrane absorber is studied experimentally.The main contents of this paper include the following aspects:?1?According to the research background of this paper,the waste heat recovery process of flue gas after desulphurization of coal-fired boilers is established.After analyzing the heat exchange process inside the membrane absorber,the mathematical model of the module is established.The accuracy of the mathematical model is verified by comparing with the experimental data in the literature.?2?Fluent software is used to simulate the flow distribution in the module,and the mathematical model is solved again with the velocity distribution in the module.The comparison results show that the accuracy of the model is further improved.By comparing the results of the two calculations,the influence of the non-uniformity of the air flow on the performance of the module is analyzed.Based on the mathematical model and the solution method,the optimum design of the distance between the tube along the wind direction and the tube along the wind direction of the membrane absorber is carried out.The simulation results show that the optimum tube spacing in the upwind direction is 2d₀,and the optimum tube spacing along the wind direction is2.5d₀,which can provide theoretical guidance for the design of membrane absorber and the construction of experimental bench.?3?The hollow fiber membrane absorber was fabricated according to the optimized design results of the membrane module,and the dehumidification test bench of the hollow fiber membrane absorber was built.The effects of inlet air flow rate,air temperature,liquid-gas ratio,solution temperature and solution concentration on the performance of the module were investigated.The results showed that the solution temperature and concentration were the main factors affecting the performance of the module.