风冷空调系统的仿真与实验研究

发布时间：2018-07-12 10:58

本文选题：风冷空调 + 计算机仿真　；参考：《天津商业大学》2017年硕士论文

【摘要】：随着国家经济的快速发展和人民生活水平的不断提高,小型风冷空调已经成为我国家庭的标准配置,而全球范围内面临的环境问题和能源形势日益严峻。这对行业的节能环保提出了更高的要求,特别是2016年《蒙特利尔议定书》基加利修订案的通过势必会加速行业内制冷剂替代的进程。因此,新型空调制冷设备的研发与优化必然是近期的发展重点。传统的产品开发模式需要大量的实验进行验证,从而导致产品的开发成本高、周期长。而计算机仿真通过将物理模型抽象为可计算的数学模型,继而通过程序计算可以预测产品结构和运行环境改变对系统带来的影响,从而减少部分实验工作量、缩短研发周期。仿真的优势在开发相似产品的过程中尤为明显,但现阶段计算机仿真在产品设计研发中仍是辅助手段。本文分析计算机仿真技术在空调制冷行业内的应用,从基础的计算方法着手介绍了一种建立风冷空调仿真系统较为通用的思路方法,以此为基础使用计算机编程实现分模块建立风冷空调系统的仿真模型,并对其中部分参数进行了实验验证。对于压缩机模块,本文采用理论分析和实验拟合相结合的方法建立转子压缩机半集中参数模型,忽略了压缩机内部参数的具体变化过程,对于结构相似的产品具有一定的通用性。前人的经验表明,换热器作为制冷系统与外界环境主要的热量交换元件,其精度对系统预测模型的结果影响很大。本文对翅片管换热器采用分布参数法建立稳态数学模型,提高了计算精度,也方便研究其内部换热特性。制冷系统模型以制冷剂流量、压缩机吸入口制冷剂过热度和系统的总充注量作为迭代收敛判据,系统各部件相互耦合满足质量守恒、能量守恒条件。本文在建立系统仿真程序后探讨了蒸发器和冷凝器进口温度及循环风量对系统性能的影响。得到结论表明:随着换热器换热条件的改善(环境温度与制冷剂相变温度接近、循环风量加大),空调系统的整体性能(制冷量、性能系数COP)会得到提升;并且根据仿真数据发现空气环境温度参数的改变对系统的影响更为直接,而风量的改变带来的性能提升存在一个临界风量,在临界风量之后再增加循环风量带来的系统性能提升效果并不明显。利用改造后的热泵干燥实验台验证了部分仿真计算的结果,改造后的实验台管道内的空气环境相对稳定可控,可以实现蒸发器入口的空气温度和流量的控制。实验验证了仿真模型的正确性,也证实了本文的计算机仿真过程的可行性,可以用于预测系统性能并以此为基础进行系统优化开发。
[Abstract]:With the rapid development of national economy and the continuous improvement of people's living standard, small air-cooled air conditioning has become the standard allocation of our family, and the global environmental problems and energy situation are increasingly serious. This puts higher demands on energy conservation and environmental protection in the industry, especially since the passage of the 2016 Montreal Protocol amendment in Kigali is bound to speed up the process of refrigerant substitution in the industry. Therefore, the R & D and optimization of new air-conditioning refrigeration equipment must be the focus of development in the near future. The traditional product development model needs a lot of experiments to verify, which leads to the high cost and long period of product development. By abstracting the physical model into a computable mathematical model, the computer simulation can predict the influence of the change of product structure and running environment on the system through program calculation, thus reducing part of the experimental workload and shortening the research and development cycle. The advantage of simulation is especially obvious in the process of developing similar products, but at present computer simulation is still an auxiliary means in product design and development. This paper analyzes the application of computer simulation technology in air conditioning and refrigeration industry, and introduces a general method of establishing air cooled air conditioning simulation system from the basic calculation method. On this basis, the simulation model of air-cooled air conditioning system is established by using computer programming, and some of its parameters are verified by experiments. For the compressor module, the semi-concentrated parameter model of the rotor compressor is established by combining theoretical analysis with experimental fitting, and the specific variation process of the internal parameters of the compressor is ignored. For similar structure of the product has a certain degree of versatility. The previous experience shows that the precision of heat exchanger, as the main heat transfer element between refrigeration system and external environment, has a great influence on the results of system prediction model. In this paper, the steady state mathematical model of finned tube heat exchanger is established by distributed parameter method, which improves the calculation accuracy and is convenient to study the internal heat transfer characteristics of finned tube heat exchanger. In the refrigeration system model, the refrigerant flow rate, the refrigerant superheat at the compressor suction port and the total charge of the system are taken as the iterative convergence criteria. The system components are coupled to each other to satisfy the mass conservation and energy conservation conditions. After the system simulation program is established, the influence of inlet temperature of evaporator and condenser and circulating air rate on the performance of the system is discussed. The results show that with the improvement of the heat transfer conditions (the ambient temperature is close to the refrigerant phase change temperature and the circulating air volume increases), the overall performance (refrigerating capacity, performance coefficient cop) of the air conditioning system will be improved. According to the simulation data, it is found that the change of air ambient temperature parameters has a more direct effect on the system, and the change of air volume has a critical air volume to improve the performance of the system. The effect of system performance improvement caused by increasing circulation air volume after critical air volume is not obvious. The results of partial simulation are verified by using the modified heat pump drying test rig. The air environment in the pipe is relatively stable and controllable, which can realize the control of air temperature and flow rate at the inlet of evaporator. The experiments verify the correctness of the simulation model and the feasibility of the computer simulation process in this paper, which can be used to predict the performance of the system and develop the system optimally.
【学位授予单位】：天津商业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TB657.2

【参考文献】