商用空调用管壳式冷凝器的研究

发布时间：2018-06-01 14:13

本文选题：管壳式冷凝器 + 传热计算　；参考：《重庆大学》2014年硕士论文

【摘要】：随着我国经济的快速发展，空调的使用日益广泛。作为能源消耗大户，建筑物的空调能耗已经占到社会总能耗的10%左右。在提倡节能减排的环境下，如何降低建筑能耗，特别是空调能耗是一个重要的课题。而提高空调系统中换热器的性能对降低空调系统的能耗有着十分重要的意义。本文以国内某制冷设备公司新产品开发为背景，应用计算机设计和数值模拟的先进理论、方法和技术，对商用空调冷水机组管壳式冷凝器进行了传热和流动方面的设计和优化。制冷剂蒸气在壳侧管束间冷凝时，由于管束间的不规则几何形状，流动情况很复杂，难以准确推算管束冷凝膜传热系数。对于制冷剂蒸气在管束换热时，应考虑冷凝液在管排之间滴落和蒸气贯穿管束的速度对液膜的影响。本文采用逐排计算法，对冷凝器多层管束的平均换热系数进行了计算并与文献结果进行了比较。发现管排之间冷凝液的滴落和蒸气贯穿管束的速度对凝结液膜厚度有很大的影响，进而影响了换热系数。本文结合管壳式冷凝器的特点，完善了冷凝器传热和压降设计计算数学模型。使用该模型计算的传热面积与某公司产品正在使用的有效传热面积最大误差为20%，而压降计算结果最大误差为15%，满足工程实际的要求。为方便设计和计算，本文将该模型用Visual Basic编制成了管壳式冷凝器设计计算软件。采用数值模拟的方法对管壳式冷凝器的壳侧流动特性做了研究，分析了由于冷凝器中挡流板的存在，对制冷剂蒸气在冷凝器内流动的影响，进而影响了其换热性能。本文提出对LSBLG400/M螺杆冷水机组冷凝器的优化方案。使用边缘向上倾斜45°的挡流板替代原来的平面挡流板，能充分利用换热器的面积，，气体得到最大限度的冷凝。通过单一优化条件的叠加，对挡流板在长度方向和距出口平面的高度进行了优化设计。得到了挡流板的最佳长度为800mm以及最佳布置高度为70mm。这种方法的优化结果较好，可以推广到其他产品的优化设计中。
[Abstract]:With the rapid development of our economy , the use of air - conditioning is becoming more and more widely . As the energy consumption is large , the energy consumption of the air - conditioning system of the building is about 10 % of the total energy consumption of the society . In the environment of promoting energy conservation and emission reduction , it is very important to reduce the energy consumption of the air - conditioning system , especially the energy consumption of the air - conditioning system .

It is difficult to accurately calculate the heat transfer coefficient of the tube bundle due to the irregular geometry of the tube bundle , and it is difficult to accurately calculate the heat transfer coefficient of the tube bundle . In this paper , the average heat transfer coefficient of the condenser multilayer tube bundle is calculated and compared with the literature results .

Based on the characteristics of shell - shell condenser , the mathematical model of condenser heat transfer and pressure drop design is perfected . The maximum error of heat transfer area calculated by using the model is 20 % , and the maximum error of pressure drop calculation is 15 % , which can meet the practical requirements of engineering . In order to facilitate the design and calculation , the design calculation software of shell - shell condenser is made by Visual Basic .

This paper studies the flow characteristics of shell side of shell - shell condenser by numerical simulation , and analyzes the influence of the baffle plate in condenser on the flow of refrigerant vapor in the condenser . The optimum design of the condenser of LSBLG400 / M screw chiller is presented . The optimum length of the baffle plate is 800 mm and the optimum layout height is 70 mm . The optimized result of this method is better , which can be extended to the optimization design of other products .
【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

【参考文献】