【作者】 黄挺；

【导师】 姜益强；

【作者基本信息】 哈尔滨工业大学 ， 供热、供燃气、通风及空调工程， 2007， 硕士

【摘要】 空气源热泵蓄能热气除霜系统（ A Thermal Energy Storage Based Hot Gas Defrosting System for Air Source Heat Pump ）是将空气源热泵除霜技术和蓄热技术有机结合起来的一种新系统。它采用蓄能相变材料将空气源热泵高效制热运行时的部分余热贮存起来,在除霜工况运行时又将其作为热泵热气除霜时的低位热源,通过相变材料的相变放热,向系统提供除霜所需的热量。这彻底解决了传统空气源热泵除霜时由于无外部热源、融霜能量主要来自压缩机做功等所引起机组运行的不稳定和可靠性差的问题。本文在分析空气源热泵蓄能热气除霜系统的形式和特点的基础上,给出了该系统不同运行模式流程,并对适合于蓄能除霜的相变材料（Phase Change Material,简称PCM）进行分析和选取;同时给出相变蓄热器的物理模型。以文献提供的除霜耗能数据为基础,对使用不同蓄能材料的某空气源热泵机组除霜用蓄能换热器进行了初步的结构设计。基于焓法对蓄热器中相变材料的传热过程建立数学模型,采用有限差分方法对模型方程进行离散,并采用交替方向隐式格式和逐线迭代的方法对离散方程组进行求解,以Na₂SO₄·10H₂O作为相变材料,不考虑散热损失的理想工况下对此蓄热器蓄热和释热过程进行模拟研究。最后本文从热媒体和相变材料两个方面,详细分析了制冷剂的入口温度、流速、入口干度,蓄热器的结构、不同PCM（RT31、A32、癸酸、Na₂SO₄·10H₂O、CaCl₂·6H₂O）等多种主要因素对蓄热器蓄热和放热特性的影响,并利用模拟结果对蓄热器参数进行了优化设计。本研究成果为空气源热泵蓄能除霜新系统的关键部件蓄能换热器的优化设计及系统各参数间的合理匹配提供了有益的参考,并为该系统的推广与应用提供了理论支持与技术储备。更多还原

【Abstract】 A Thermal Energy Storage Based Hot Gas Defrosting System for Air Source Heat Pump is a new system combinding technology of Defrosting System for Air Source Heat Pump with energy storage. An energy storage equipment of phase change is added to the system to store surplus heat when heap pump runs in high efficiency and the heat is used as low grade energy for defrost. Then the energy in the PCM is discharged in the hot gas defrost process. So the problems of the energy lacking for defrost or from mostly compressor are thoroughly solved.Firstly, the paper presents different mode flow of new system on basis of analyzing the characteristic of Defrosting System for Air Source Heat Pump （DSASHP）. Then it supplies a physical model of phase change heat accumulator by analyzing and choosing PCM, and discusses energy consumption problem for DSASHP, then designes heat accumulator equipment with different PCM on basis of experiment data of defrosting energy consumption.Secondly, a mathematic model for heat-transfer process of phase change material in heat accumulator was developed based on enthalpy method and discreted with finite difference method, and solved by alternating direction implicit method and iteration method. Taking Na₂SO₄·10H₂O as phase change material, without regarding to heat dissipation, the process of thermal storage and release in heat accumulator was simulated.Eventually, the influence of inlet temperature, dryness fraction of the refrigerant, the configuration of heat accumulator and PCM on heat charge and discharge were analysed. Then heat accumulator was optimzed using the results.This paper gives reference to the matching of the parameters and the optimal design of the system, and supplies theory support and technology accumulation for its popularization and application.更多还原