
2018年第9期(总第249期)
doi:10.3969/j. issn. 1009 3230.2018.09.001
应用能源技术
气候环境实验室换热器除霜技术的研究
白东乔,刘海燕
(中国飞机强度研究所,西安710065)
摘要:气候环境实验室在进行低温、高湿工况试验时,换热器表面会结霜。换热器结霜将增加换热空气的流动阻力、导致换热效率下降。为保证空气处理系统正常运行需要对换热器进行除霜。文中通过建立换热器模型对换热器结霜和除霜过程进行仿真分析,计算了结霜和除霜过程中霜层厚度、滞留水量的变化过程,提出了除霜开始判据和结束判据。以此为理论依据对实验室换热器除需方案和除需流程进行了优化,并在实验室调试过程中得到应用,取得了良好效果。
关键词:气候环境实验室;换热器;结霜;除霜判据;除霜流程
中图分类号:X382
文献标志码:B
文章编号:10093230(2018)09000104
ResearchonDefrostingTechnologyofHeatExchanger
inClimateEnvironmentLaboratory
BAI Dong qiao, LIU Hai yan
(AVIC Aircraft Strength Research Institute,Xi'an 710065, China)
Abstract:The surface of exchanger will be frosted under low temperature and high humidity conditions in the climate environment laboratory. The frosting of heat exchanger will increase the flow resistance of heat exchange air, which leading to the decrease of heat exchange efficiency. Defrosting of heat exchangers is required to ensure the normal operation of air treatment system. The frosting and defrosting process of the exchanger was simulated and analyzed by establishing the heat exchanger model. The change process of frosting amount in the process of defrosting and defrosting was calculated. The starting and ending criteria of defrosting were established. The defrosting scheme and defrosting flow of the laboratory heat exchanger were optimized based on the theory in this paper which was applied in the laboratory and achieved good results.
Key words : Climate environment laboratory ; Heat exchanger frosting; Defrost criterion; Defrost process
0引言
翅管型换热器在表面温度低于周围空气的露点温度并且低于0℃时,换热器表面就会结霜,结霜会导致换热器的传热效率下降、风阻增加,在结霜到一定程度时,需要对换热器进行周期性除霜为了对换热器在结霜-除霜过程进行分析,需要建立结霜一除霜物理模型
Jeng-MinHuang提出了结霜过程中的数值模型(2),通过对模型进行计算得到了不同翅片间
收稿日期:2018-0611
修订日期:20180721
作者简介:白东乔(1990-),男,硕士研究生,研究方向为气
候环境适应性分析与试验技术。
万方数据
距下,换热器传热效率与霜层厚度的关系;J.Al bertoDopazo等人建立了换热器除霜模型(】,通过对换热器进行单元分解,得到了换热器在除霜过程的各参数动态变化情况。
大型气候环境实验室是为了模拟真实室外环境,以完整的飞机作为实验对象,其实验工况包括高温、低温、降雪、冻雨、冻雾等[1]。在降雪、冻雨、冻雾工况中,因为环境温度低,湿度高,换热器在换热过程中结霜,需要对换热器进行除霜操作。实验室进行试验的过程中发现除霜的效果和周期是保证空气处理系统能否正常工作的关键。因为无法直接对结霜过程进行直接监测的情况,建立