多联式空调（热泵）系统变工况性能仿真研究

发布时间：2018-03-09 16:23

本文选题：多联机　切入点：性能　出处：《西安建筑科技大学》2017年硕士论文　论文类型：学位论文

【摘要】：近年来,中国的建筑空调能耗不断升高。区别于传统形式的中央空调系统,多联式空调系统所需设备少,布置灵活,可以实现“部分时间,部分空间”的灵活使用方式,已经在办公建筑、医院建筑和高级住宅等建筑中广泛使用。多联机空调系统在设计工况下运行能达到其设定的性能要求。在参数改变时,多联机对应的性能将如何改变,是一个值得探讨的问题。针对这个问题,本文具体做了如下工作:首先分析比较了仿真中的热物性计算方法,然后通过仿真方法分析了多联式空调系统中各部件(压缩机、电子膨胀阀、冷凝器和蒸发器)的性能;最后,分析了由这些部件所构成的系统的性能。本研究主要得到的结论如下:(a)制冷剂热物性模型除了要考虑精度、速度和稳定性外,还要考虑计算的可逆性。采用状态方程法,其计算速度在一般情况下并不会损失太多;(b)压缩机采用十系数仿真模型,计算速度和精度都能够得到保证;(c)换热器模型的两种建模方式中,集中参数模型所需参数较分布参数模型要少,因此相对简单;(d)系统中风冷换热器的性能受到多种因素的影响:换热器的结构、换热管外侧的迎面风速、湿空气进口参数、制冷剂进口参数和制冷剂的流量。这些因素对换热量的影响程度各不相同;(e)系统的整体性能除了受到以上因素的影响,还受到电子膨胀阀的流通截面积和压缩机的转速的影响。单纯调节某一个室内机的电子膨胀阀会影响其他室内机的性能,必须结合控制算法调整压缩机的转速才能达到良好的控制效果。
[Abstract]:In recent years, the energy consumption of building air conditioning in China has been increasing continuously. Different from the traditional central air conditioning system, the multi-connected air conditioning system requires less equipment and has flexible layout, so it can realize the flexible use of "part time, part space". It has been widely used in office buildings, hospital buildings and advanced residential buildings. Multi-on-line air conditioning systems can meet their performance requirements under design conditions. Aiming at this problem, this paper has done the following work: firstly, the calculation methods of thermal properties in simulation are analyzed and compared, and then the components (compressors, compressors, etc.) in multi-connected air conditioning system are analyzed by simulation method. The performance of the electronic expansion valve, condenser and evaporator is analyzed. Finally, the performance of the system composed of these components is analyzed. The main conclusions of this study are as follows: in addition to considering accuracy, speed and stability, the model of thermal properties of refrigerant is as follows. It is also necessary to consider the reversibility of calculation. By using the equation of state method, the calculation speed of the compressor will not lose much in general.) the compressor adopts a ten-coefficient simulation model. In the two modeling methods of the heat exchanger model, the centralized parameter model needs less parameters than the distributed parameter model. Therefore, the performance of air-cooled heat exchangers in a relatively simple system is affected by many factors: the structure of the heat exchanger, the wind speed outside the heat exchanger tube, the inlet parameters of wet air, The parameters of refrigerant inlet and the flow rate of refrigerant. The influence of these factors on the heat transfer is different.) the overall performance of the system is affected by the above factors. It is also affected by the flow area of the electronic expansion valve and the speed of the compressor. Simply adjusting the electronic expansion valve of one indoor unit will affect the performance of other indoor machines. In order to achieve good control effect, the speed of compressor must be adjusted with control algorithm.
【学位授予单位】：西安建筑科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU831

【相似文献】