热泵式溶液调湿新风机组性能研究

发布时间：2018-05-27 09:24

本文选题：溶液调湿 + 气流分布　；参考：《安徽工业大学》2017年硕士论文

【摘要】：随着节能减排的深入,以及人们对室内空气品质要求的提高,溶液调湿新风机组逐渐进入市场。但是目前在溶液调湿产品冬季加湿性能及塔内气流均匀性方面研究不足。本文以不同填料冬季加湿性能参数及塔内填料最优摆放形式的确定为研究目标,结合实验分析和数值模拟的方法展开研究。首先,设计一台额定风量为500 m3/h的热泵热平衡式溶液调湿新风机组并对其进行可行性分析。机组由溶液循环系统、热泵系统、风系统、电气控制系统及测试系统五部分组成。机组的特色在于通过单溶液槽的设计方法实现溶液浓度的动态平衡,及通过6 kW的辅助冷凝器实现热泵系统的能量平衡。通过对系统lgp-h图的分析以及相关技术调研,进一步确定机组设计方案的可行性,并完成实验台的搭建工作。其次,在实验台搭建完成后开展机组冷态实验,主要包括风系统、水系统及热泵系统的调试工作。首先对实验台进行密封性测试,系统漏风率测试结果在±20%以内,能保证实验数据的可靠性。然后通过飘带、烟雾示踪及化学显色法对塔内气流均匀性进行定性和定量分析。通过水系统实验确定了布液器最优开孔数量与流量之间的函数关系,结合实验结果得到重力型排管布液器的流量系数约为0.56。热泵系统调试主要包括辅助冷凝器开、关状态,膨胀阀开度调节以及泵与风机流量调节对系统性能的影响,调试得到膨胀阀开度的最优区间为2.5-3.5。根据冷态实验结果可制定实验台各子系统的优化控制策略。再次,通过数值模拟方法确定塔内填料最优摆放形式及其优化策略。根据各填料盘波纹板法线间的几何关系共制定四种模拟工况,模拟结果表明波纹板法线交叉形式对应的塔内气流均匀性最好,且影响气流分布效果的关键因素是底盘填料的摆放形式及结构参数。根据四种工况的对比结果定义了气流均匀性过渡层的概念,并对过渡层高度进行了优化模拟,得到过渡层最优高度与填料塔截面风速间的函数关系。模拟结果可为填料盘数量及高度的确定提供理论指导。最后,结合冷态实验及模拟结果开展冬季工况填料性能热态实验。通过对SKB-350Y、7090湿帘、多面空心球及空塔四种工况下送风温度、加湿量、传热/传质系数及制热/加湿性能系数的综合分析,得到7090湿帘的综合性能最优,对应的体积传质系数和传热系数分别为4.37 kg/m3/s和23.83 W/m2/℃。结果表明规整填料综合性能优于散装填料,空塔工况性能最差,但单独从传热或传质角度考虑,三种填料各有所长,实验结果对机组设计中不同填料的应用具有一定的借鉴意义。此外,通过实验还确定了溶液浓度与液位之间存在的函数关系,据此可实现机组运行过程中浓度的可视化及实时调控。
[Abstract]:With the deepening of energy saving and emission reduction and the improvement of indoor air quality requirements, the new air conditioning unit has gradually entered the market. However, the wetting performance of the solution and the uniformity of air flow in the tower are not studied at the present time. It is defined as the research goal, combining the experimental analysis and the numerical simulation method to carry out the research. First, a heat pump heat pump heat pump new wind turbine unit with a rated air volume of 500 m3/h is designed and its feasibility is analyzed. The unit is composed of five parts: solution circulation system, heat pump system, wind system, electric control system and test system. The characteristic is that the dynamic balance of the solution concentration is realized through the design method of single solution slot, and the energy balance of the heat pump system is realized through the 6 kW auxiliary condenser. Through the analysis of the lgp- h diagram of the system and the related technology research, the feasibility of the design scheme of the unit is further determined and the construction of the test platform is completed. Secondly, the actual system is completed. After the test platform was completed, the cold experiment was carried out, mainly including the wind system, the water system and the heat pump system. First, the test bench was sealed. The test results of the air leakage rate of the system were within + 20%, and the reliability of the experimental data could be ensured. Then the airflow uniformity in the tower was carried out through the drift belt, the smoke tracing and chemical color rendering method. Qualitative and quantitative analysis is carried out. Through the water system experiment, the function relationship between the optimum opening number and the flow rate of the distributor is determined. According to the experimental results, the flow coefficient of the gravity type drain pipe distributor is about 0.56. heat pump system debugging mainly including the auxiliary condenser opening, the closing state, the expansion valve opening adjustment, and the pump and fan flow regulation. The optimal interval of the opening degree of the expansion valve is obtained by debugging. The optimal control strategy for each subsystem of the experimental platform can be formulated by 2.5-3.5. according to the cold test results. Thirdly, the optimal placement and optimization strategy of the packing are determined by the numerical simulation method. Four simulation conditions are made. The simulation results show that the uniformity of air flow in the tower is the best, and the key factor affecting the air distribution is the arrangement of the chassis and the structure parameters. The concept of the transition layer of the airflow uniformity is defined according to the comparison results of the four working conditions, and the height of the transition layer is carried out. The function relationship between the optimal height of the transition layer and the wind speed of the cross section of the packing tower is obtained. The simulation results can provide theoretical guidance for the determination of the number and height of the packing plate. Finally, the thermal experiments of the packing performance in the winter conditions are carried out with the cold state experiment and the simulation results. The four kinds of SKB-350Y, 7090 wet curtain, multi surface hollow sphere and empty tower are carried out. The comprehensive analysis of air supply temperature, humidification, heat transfer / mass transfer coefficient and heat / humidification coefficient of the 7090 wet curtain is obtained. The corresponding volume mass transfer coefficient and heat transfer coefficient are 4.37 kg/m3/s and 23.83 W/m2/ respectively. The results show that the comprehensive properties of the structured packing are better than the bulk packing, but the performance of the air tower is the worst, but the performance of the air tower is the worst. From the viewpoint of heat transfer or mass transfer alone, the three kinds of fillers have their own advantages. The experimental results have certain reference significance for the application of different packing in the design of the unit. In addition, the relationship between the concentration of solution and the liquid level has been determined through the experiment. Accordingly, the visualization and real-time control of the concentration in the operation of the unit can be realized.
【学位授予单位】：安徽工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU831

【参考文献】