Synchronous calculation of transient hygrothermal conditions of indoor spaces and building envelopes
Synchronous calculation of transient hygrothermal conditions of indoor spaces and building envelopes
复制标题
室内空间与建筑围护结构瞬态湿热条件同步计算
DOI：
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发表时间：
2001
期刊：
影响因子：
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通讯作者：
Karl Grau Sørensen
中科院分区：
文献类型：
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作者：
C. Rode;Karl Grau Sørensen
现有的用于建筑物动态热分析的计算机模型已经扩展到考虑室内空间的水分平衡。新模型不仅考虑了空间中湿度的产生及其与室外或空调空气的通风，还考虑了室内和外部建筑结构以及室内家具的水分缓冲。该模型包含在现有的综合建筑设计工具BSim2000中。综合模型的观点是在同时计算中预测室内空间的湿度条件，并通过相邻建筑结构的整个厚度来预测热湿条件。由于围护结构、室内布置和室内空间的湿热条件相互影响，因此应具有较好的预测能力。室内空间的湿度是决定室内空气质量的最重要因素之一，室内环境中许多与健康有关的问题都与室内高湿度有关。此外，高室内湿度是建筑围护结构中有害湿气积聚的最重要原因之一，并且可能是建筑物占用空间加热或冷却的额外能源消耗的原因。用新鲜空气通风是改善室内高湿度问题的一种方法，但通风需要能量来调节空气并运行通风系统的风扇。因此，能够设计出在水分供应和所需通风之间取得适当平衡的建筑是一种兴趣。然而，室内空气的湿度状况不仅是当前活动供湿和实际通风量的结果。还必须考虑到许多建筑材料和室内陈设具有吸湿性，因此它们可以缓冲室内湿度。人们做了许多尝试来模拟室内湿度条件。这些尝试从完全不考虑室内水分缓冲作用的简单稳态模型（伦敦模型，1971）中有所不同。其他的是经验模型，承认缓冲效应，但物理上没有描述缓冲效应（土屋，1980），以及更多基于物理的模型，考虑了建筑元素表层的缓冲作用（例如有效湿气渗透深度模型，Kerestecioglu等人，1990）。然而，这些模型都无法预测结构内部的深层情况，而且它们通常没有考虑通常存在于室内气候和外部建筑围护结构之间的非等温条件。因此，开发同步预测室内空气湿度条件、建筑围护结构材料和家具的方法具有重要意义。例如，这样的发展正在进行中，以补充美国能源部的EnergyPlus计划（Crawley et al., 2000）。然而，EnergyPlus基于响应因子法，由于瞬态水分传递是非线性现象，因此在计算瞬态水分传递时可能会有一些困难（Liesen et al. 1999）。本文将描述1998年开始的丹麦建模活动，其总体目的是开发建筑物湿度条件的分析工具，以调查和优化建筑物需求控制通风的操作策略。该模型基于有限控制体积法，能够管理非线性条件。如果不知道热条件，就不能预测湿度条件。因此，开发整个建筑湿度条件预测模型作为现有工具的延伸，对建筑物进行详细的热分析是非常明显的。这样的工具已经可以预测室内环境和所有邻近建筑构件的热状况。通常，热计算工具本身相当复杂，它们的热预测已经得到验证，并且它们已经有一个用户界面。一个这样的程序
An existing computer model for dynamic thermal analysis of buildings has been extended to consider the moisture balance of the interior spaces. The new model takes into consideration not only the production of humidity in the spaces and their ventilation with outdoor or conditioned air, but also the buffering of moisture in interior and exterior building constructions, and in interior furnishing. The model is included in an existing integrated building design tool, BSim2000. The perspective of the integrated model is to predict in a simultaneous calculation both the humidity conditions of indoor spaces, and the thermal and moisture conditions through the whole thickness of adjacent building constructions. Since the hygrothermal conditions of envelopes, furnishing and indoor spaces influence on each other, better prediction capabilities should be achieved in all. INTRODUCTION Humidity in indoor spaces is one of the most important factors to determine the indoor air quality, and many health related problems in the indoor environment can be associated with high indoor humidity. Furthermore, high indoor humidity is among the most important reasons for harmful accumulation of moisture in the building envelope, and can be a reason for extra energy consumption for heating or cooling of the occupied spaces of buildings. Ventilation with fresh air is a way to improve the problems of high indoor humidity, but ventilation requires energy to condition the air and to run the fans of the ventilation systems. So there is an interest to be able to design buildings for a suitable balance between moisture supply and required ventilation. However, the humidity condition of indoor air is result not only of moisture supply from current activities and the actual ventilation rate. It must be considered also that many building materials and interior furnishing are hygroscopic, so they act as buffers for the indoor humidity. Many attempts have been made to model the indoor humidity condition. The attempts vary from simple steady state models that completely disregard the indoor moisture buffering (the Loudon model, 1971). Other are empirical models that acknowledge, but physically do not describe the buffering effect (Tsuchiya, 1980), and more physics based models that consider the buffering in a surface layer of the building elements (e.g. the Effective Moisture Penetration Depth model, Kerestecioglu et al., 1990). However, none of these models make it possible to predict the conditions deeper in the structures, and they often do not consider the non-isothermal conditions that normally exist between the indoor climate and the exterior building envelope. Consequently, there is a substantial interest to develop methods for synchronous prediction of humidity conditions of the indoor air, of the materials in the building envelope and in furnishing. For instance, such development is under way to complement the DOE EnergyPlus program (Crawley et al., 2000). However, EnergyPlus is based on a response factor method, which may have some difficulty in calculating transient moisture transfer, as this is a non-linear phenomenon (Liesen et al. 1999). This paper will describe a Danish modelling activity that was started in 1998 with the overall purpose to develop an analytical tool for moisture conditions in buildings to investigate and optimise operational strategies for demand-controlled ventilation of buildings. The new model is based on a finite control volume method that is able to manage the non-linear conditions. Moisture conditions cannot be predicted without knowing the thermal conditions. It is quite obvious therefore to develop the model for prediction of whole building moisture conditions as an extension to an existing tool for detailed, thermal analysis of buildings. Such a tool will already predict the thermal condition of the indoor environment and all the adjacent building components. Normally, the thermal calculation tools are rather elaborate themselves, their thermal predictions have already been validated, and they already have a user interface. One such program