往复型蓄热新风热回收模型验证及建模优化

发布时间：2018-03-21 21:51

本文选题：建筑节能　切入点：通风热回收　出处：《中国建筑科学研究院》2017年硕士论文　论文类型：学位论文

【摘要】：随着建筑节能工作的不断开展和深入,目前在建筑通风领域的建筑节能手段正越来越受到更多的关注和重视,其中通风中的热回收技术一直是该方向的重点研究内容之一。另一方面,相变材料蓄热量大的特点以及相对稳定的热工况在诸多领域已经得到应用,并取得了良好的效果。相变通风热回收系统则是将考虑将相变蓄能技术应用于通风系统,基于往复式通风这一运行模式,利用相变材料的蓄、放热性能,达到通风热回收的目的,从而降低建筑的通风能耗。本次研究以相变通风热回收系统为研究对象,通过实验与模拟结合的方式重点探索其传热特性及影响最终相变通风热回收效果的因素。首先对作为相变通风热回收系统基础的往复式通风进行了一定的研究,以CO2为例对比了往复式通风和常规混合通风两种通风方式下的室内污染物分布情况,分析应用往复式通风对住宅通风效果的影响。结果表明往复式通风是一种优秀的住宅通风方式。随后开始论述本次研究的主体内容部分。首先是介绍了本次研究开展的各项准备工作,例如相变材料的选择、通风器的初步设计等。随后是本次研究进行的模拟工作,本次研究采用Fluent软件进行相关的模拟计算,并介绍了采用的模拟方法,并分别进行了相变传热和作为基础对照的显热传热的模拟计算工作,以便随后将模拟结果与之后的实验结果进行对比。之后介绍了本次研究中实验部分的内容,首先对相变传热及显热传热实验的实验过程、实验结果进行了相关说明和分析。随后将模拟结果和实验结果进行了对比,对比结果显示,显热传热实验的模拟计算结果与实验结果对照情况较好,但相变传热实验模拟与实验结果间存在较大偏差。在进行了追加的单个相变单元相变特性实验后,认为过冷、相变材料特性发生变化以及实验中存在一定的漏热现象是导致结果差异的主要因素。在经过了显热传热实验以及单个相变单元相变特性实验两个实验结果的验证后,为进一步分析相变传热的影响因素,采用模拟分析的方法研究了相变材料物性对相变传热效果的影响,最后以显热通风热回收为例计算了其他因素对基于往复式通风的通风热回收效率的影响。分析结果显示,相变材料物性对相变材料传热具有明显影响,但从通风器整体而言影响蓄热量的因素对最终通风效果的影响更加显著;缩短循环周期、减小风量以及提高进出口温差可以提高整体的热回收效率。
[Abstract]:With the development and deepening of building energy conservation, more and more attention has been paid to building energy conservation in the field of building ventilation. The heat recovery technology in ventilation has been one of the key research contents in this direction. On the other hand, the characteristics of large heat storage capacity of phase change materials and relatively stable thermal conditions have been applied in many fields. The phase change ventilation heat recovery system will consider the application of phase change energy storage technology in the ventilation system. Based on the reciprocating ventilation operation mode, the heat storage and heat release performance of phase change materials will be utilized. To achieve the purpose of ventilation heat recovery, thus reducing the ventilation energy consumption of the building. This study takes the phase change ventilation heat recovery system as the research object. Through the combination of experiment and simulation, the heat transfer characteristics and the factors that affect the heat recovery effect of the final phase change ventilation are explored. Firstly, the reciprocating ventilation, which is the basis of the phase change ventilation heat recovery system, is studied to a certain extent. Taking CO2 as an example, the distribution of indoor pollutants under reciprocating ventilation and conventional mixed ventilation is compared. This paper analyzes the effect of reciprocating ventilation on the ventilation effect of residence. The result shows that reciprocating ventilation is an excellent ventilation method. Then, the main content of this study is discussed. First, the research is introduced. Preparatory work carried out, For example, the selection of phase change materials, the preliminary design of the ventilator, etc. Then, the simulation work of this study was carried out. The Fluent software was used to carry out the relevant simulation calculation, and the simulation method was introduced. The simulation and calculation of phase change heat transfer and sensible heat transfer are carried out respectively, so that the simulation results can be compared with the later experimental results. Then, the contents of the experimental part of this study are introduced. The experimental results of phase change heat transfer and sensible heat transfer are explained and analyzed, and the simulation results are compared with the experimental results. The results of simulation and calculation of sensible heat transfer experiment are in good contrast with the experimental results, but there is a big deviation between the experimental results of phase change heat transfer experiment and the experimental results. After the phase change characteristic experiments of a single phase change unit are carried out, it is considered that the supercooling is very important. The variation of phase change material and the existence of heat leakage in the experiment are the main factors leading to the difference of the results. In order to further analyze the influencing factors of phase change heat transfer, the effect of physical properties of phase change material on phase change heat transfer effect was studied by means of simulation analysis. Finally, the effect of other factors on the efficiency of ventilation heat recovery based on reciprocating ventilation is calculated, and the results show that the physical properties of phase change materials have obvious influence on the heat transfer of phase change materials. However, the factors affecting the heat storage of the ventilator as a whole have a more significant effect on the final ventilation effect, and the overall heat recovery efficiency can be improved by shortening the cycle period, reducing the air volume and increasing the temperature difference between the inlet and outlet.
【学位授予单位】：中国建筑科学研究院
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU834

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