空调用自复叠系统的模拟计算及其高压侧配管应力分析

发布时间：2018-03-25 14:42

本文选题：湿度　切入点：温湿度独立控制　出处：《重庆大学》2014年硕士论文

【摘要】：目前，大多数房间空调器都是以R410a为制冷剂的单级蒸气压缩式制冷系统，通过室内机与室内空气热量的交换完成温湿度的控制任务。虽然这能够达到人体对于温度的基本要求，，但是仅仅使用一个蒸发器很难实现温湿度双参数的精确控制，往往由于单一地强调对室内温度的控制而忽略了人体对于湿度的需求，导致温、湿度不能同时满足人体要求。同时，由于制冷工质在制冷系统冷凝器和蒸发器中保持等温冷凝和等温蒸发，很大程度上增加了制冷剂与室内空气之间的传热温差，使循环的不可逆性增加，制冷系数下降，从而造成一些不必要的能量消耗。针对现有空调制冷系统所存在的问题，本文根据自复叠制冷系统易于实现双温区的特点，将其做了一些改动用于房间空调器，从而设计出了一种能够实现温湿度独立控制的房间空调器制冷系统，该系统兼顾对温度和湿度的处理过程，能够避免了常规空调系统中温湿度联合处理所带来的损失，起到了更好的节能效果。由于温度和湿度采用了独立的调节环节，克服了常规空调系统中不易于同时满足人体对温湿度参数的要求，避免了室内湿度过高或过低的现象。本文从以下几个方面对该系统做了研究和分析： ①基于CFCs替代物的选择要求以及混合工质的温度滑移特性，选取R32和R326fa作为制冷系统的制冷剂； ②针对传统的气体状态方程不能够描述气液两相P-V-T关系的问题，采用状态方程法（EOS法），即结合PR状态方程式对处于气液相平衡的混合工质的热力学参数进行计算； ③编制混合工质物性计算程序模块，完成制冷循环过程基本热物性的计算，为循环系统的设备选型提供相应的参数； ④建立自复叠循环系统物理模型，编写气液相平衡模拟程序。分析了循环浓度和压缩机W'比对该制冷系统性能系数的影响，从而能够找到在给定工况下的最佳浓度比及其压力比； ⑤考虑到系统高压侧配管存在的安全隐患，针对压缩机排气侧配管应力进行了试验研究和CAE模拟分析。
[Abstract]:At present, most room air conditioners are single-stage vapor compression refrigeration systems with R410a as refrigerant. The control tasks of temperature and humidity are accomplished by the exchange of heat between indoor air and indoor machines, although this can meet the basic requirements of human body for temperature. However, it is difficult to realize the accurate control of temperature and humidity by using only one evaporator. Because of the single emphasis on the control of indoor temperature, the human body's requirement for humidity is neglected, which leads to the temperature. The humidity can not meet the requirements of the human body at the same time. At the same time, because the refrigerant keeps isothermal condensation and evaporation in the condenser and evaporator of the refrigeration system, the heat transfer temperature difference between the refrigerant and the indoor air is increased to a great extent. The irreversibility of the cycle is increased and the refrigeration coefficient is reduced, resulting in some unnecessary energy consumption. In view of the problems existing in the existing air-conditioning refrigeration system, according to the characteristics of the self-cascade refrigeration system which is easy to realize the double temperature zone, some modifications are made for the room air conditioner. Thus, a room air conditioner refrigeration system which can realize the independent control of temperature and humidity is designed. The system takes into account the processing process of temperature and humidity, and can avoid the loss caused by the combined treatment of temperature and humidity in the conventional air conditioning system. Because the temperature and humidity are adjusted independently, it is difficult to meet the requirements of temperature and humidity parameters in the conventional air conditioning system at the same time. The system is studied and analyzed from the following aspects:. 1 based on the choice of CFCs substitute and the temperature slip characteristics of mixed refrigerants, R32 and R326fa are selected as refrigerants in refrigeration system; (2) in view of the problem that the traditional gas equation of state can not describe the gas-liquid two-phase P-V-T relationship, the thermodynamic parameters of the mixture in gas-liquid equilibrium are calculated by using the EOS method combined with the PR equation of state. (3) compiling the calculation program module of the physical properties of the mixed working fluid, completing the calculation of the basic thermal properties of the refrigeration cycle, and providing the corresponding parameters for the equipment selection of the circulating system; (4) the physical model of self-stacking cycle system is established, and the simulation program of gas-liquid phase equilibrium is compiled. The effects of cycle concentration and compressor W' ratio on the performance coefficient of the refrigeration system are analyzed. Thus, the optimum concentration ratio and pressure ratio under given working conditions can be found. 5. Considering the hidden danger of high pressure side pipe distribution in the system, the stress of the compressor exhaust side pipe is studied experimentally and simulated by CAE.
【学位授予单位】：重庆大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TB657.2

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