Abstract:

The fin and tube heat exchanger is the most commonly used type of heat exchangers in household air conditioners. The most direct way to reduce the production cost of fin and tube heat exchangers is the replacement of copper tubes with aluminum tubes. There is a lack of design experience in the aluminum tube and aluminum fin heat exchanger currently, and the development of a simulation model to predict performance can improve design efficiency. This study builds a three dimensional steady state distributed-parameters model of heat exchangers, and the adjacent matrix in graph theory is introduced to describe the complex refrigerant circuitry in heat exchangers. An overall alternating iterative algorithm is adopted, and energy equations for all control volumes and momentum equations of all control volumes are solved dependently to decouple the relationship of conservation equations. A digital simulation design software with an interactive graphical interface is implemented. Experimental validations on prototypes with different combinations of aluminum tubes and aluminum fins are carried out, and the comparison between the experimental results and the simulation results shows that under four working conditions, the deviations of predicted heat transfer, pressure drop inside and outside the pipe are within ±5%, ±10%, and ±10%, respectively. The aluminum tube and aluminum fin heat exchanger model can meet the accuracy requirement of design.

Key words: household air conditioner, aluminum tube heat exchanger, steady-state, model, computer simulation

摘要：

翅片管式换热器是家用空调器中最常用的换热器型式，将其中的铜管替换成铝管是降低翅片管式换热器生产成本最直接的方法。目前铝管铝翅片换热器的设计经验缺乏，开发铝管铝翅片换热器的仿真模型来预测性能可以提高设计效率。建立换热器的三维稳态分布参数模型，引入图论中的邻接矩阵来描述换热器中的复杂流路。采用交替迭代的换热器性能仿真算法，通过单独求解动量、能量方程达到对方程组的解耦。据此开发具有交互式图形界面的数字化仿真设计软件。在不同铝管和铝翅片组合的样机上开展实验验证，样机的实验结果和软件的仿真结果对比表明，在额定制冷、43℃高温制冷、额定制热、低温制热四种工况下，软件预测的换热量、管内压降和管外压降的误差分别在±5%、±10%和±10%以内。开发的铝管铝翅片换热器模型能够满足换热器设计的精度需求。

关键词: 家用空调器, 铝管换热器, 稳态, 模型, 计算机模拟