双罐式气泵供液制冷系统的理论与实验研究

发布时间：2018-05-17 19:41

本文选题：气泵供液 + 传热效率　；参考：《天津商业大学》2014年硕士论文

【摘要】：随着现代社会中各种科学技术的不断发展，制冷和冷藏作为科学技术发展的重要学科之一，无论是工业生产还是民用生活科技等众多领域都得到广泛使用；因此制冷系统节能的研究和高性能系统的研制和开发就成为制冷领域探索的核心课题。提高蒸发器传热效率的主要途径在于增大蒸发器管路空气侧放热系数和制冷剂侧放热系数，蒸发器管空气侧采用高效翅片或者强化空气流动速度后可以有效提高空气侧传热系数，但并不能无限提高。过度强化空气流动，会带来冷藏物品的干耗等问题，同时也增加了风机电能和蒸发器的负荷。因此提高制冷机侧制冷系数便成为了一条节能高效的蹊径。提高制冷剂流速是增大制冷剂侧放热系数的主要方式，相对于传统直接膨胀供液方式，由于制冷系统中压缩机的稳定运行控制制冷剂的循环量，蒸发器的供液量与蒸发量基本相等，难以调节。因此利用气泵供液装置提高蒸发器中制冷剂供液量，使其大于蒸发量来实现提高制冷剂流速强化传热性能，实现蒸发器的超倍供液，增大液态制冷剂和蒸发管内壁的接触面积，提高蒸发器传热效率[1 2]。搭建气泵供液制冷系统实验台，设计气泵供液控制装置电气线路图，控制整个气泵双桶连续供液稳定。采用热平衡法检验系统在不同供液量下的运行特性，并验证传热效果。实验中调节供液气压来控制再循环蒸发器供液量，调节制冷系统中的循环倍率，在循环倍率随着供液气压的增加而逐渐增大时，蒸发器的传热量会升至最大值。在不同的工况条件下测定制冷系统的压力、温度和制冷量等技术参数，得出气泵供液方式与直接膨胀供液方式的系统性能差异（如传热系数、制冷量和系统COP）以及变化规律。
[Abstract]:With the continuous development of science and technology in modern society, refrigeration and refrigeration as one of the important disciplines of science and technology development, whether industrial production or civil life science and technology and many other fields have been widely used. Therefore, the research on energy saving of refrigeration system and the research and development of high performance system have become the core subject in refrigeration field. The main way to improve the heat transfer efficiency of evaporator is to increase the air side heat release coefficient and refrigerant side heat release coefficient of evaporator. The heat transfer coefficient of the air side of the evaporator tube can be improved effectively by using high efficiency fin or enhanced air flow velocity, but it can not be increased indefinitely. Excessive enhancement of air flow will cause dry consumption of refrigerated items and increase fan power and evaporator load. Therefore, improving the refrigeration coefficient on the side of the refrigerator has become a path of energy saving and high efficiency. Increasing the flow rate of refrigerant is the main way to increase the exothermic coefficient of refrigerant side. Compared with the traditional way of direct expansion and liquid supply, the stable operation of compressor in refrigeration system controls the circulation of refrigerant. The amount of liquid supplied by evaporator is basically equal to that of evaporator, so it is difficult to adjust. Therefore, the liquid supply of refrigerant in evaporator can be increased by using the device of gas pump to increase the refrigerant flow rate and enhance the heat transfer performance of evaporator, to increase the contact area between liquid refrigerant and the inner wall of evaporator, and to improve the heat transfer performance of refrigerant flow rate, so as to increase the contact area between liquid refrigerant and the inner wall of evaporator tube. Improve the heat transfer efficiency of evaporator [1 / 2]. The experiment platform of air pump liquid supply refrigeration system was built, and the electric circuit diagram of the gas pump liquid supply control device was designed to control the continuous liquid supply stability of the whole gas pump. The heat balance method was used to test the operating characteristics of the system under different liquid supply and to verify the heat transfer effect. In the experiment, adjusting the air pressure to control the liquid supply of the recirculating evaporator and regulating the circulation rate in the refrigeration system, the heat transfer rate of the evaporator will rise to the maximum when the circulation rate increases with the increase of the supply pressure. The pressure, temperature and refrigerating capacity of the refrigeration system are measured under different operating conditions. The system performance differences (such as heat transfer coefficient, refrigerating capacity and system COP) between the liquid supply mode of the gas pump and the direct expansion liquid supply mode are obtained as well as the variation law.
【学位授予单位】：天津商业大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TB657

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