Abstract An accurate temperature gradient calculation is essential for displacement ventilation (DV) system design, since it directly relates to the calculation of supply air flow rate. Several simplified nodal models were developed and implemented in the various building simulation programmes to estimate the temperature stratification in rooms with displacement ventilation. However, the most commonly used models do not take into account the types and locations of the heat loads in rooms with DV. As a result, the calculated air temperature in the occupied zone can defer from the real one by 2–3 °C, which causes poor thermal comfort and inadequate sizing of the ventilation and cooling systems. In the present study, the nodal model was proposed to provide a simplified technique to predict the vertical temperature gradient in rooms with DV. In addition, the effect of the room height and locations of the indoor heat sources were studied for the typical office environment. The measurement data were compared with the existing nodal models and the proposed nodal model in terms of predicting the occupied zone temperatures. The presented nodal model demonstrates an accurate calculation of the temperature gradient for the typical heat loads and combinations of them.

中文翻译：

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置换通风的室内空气温度曲线建模

摘要 准确的温度梯度计算对于置换通风 (DV) 系统设计至关重要，因为它直接关系到送风流量的计算。在各种建筑模拟程序中开发并实施了几个简化的节点模型，以估计置换通风房间的温度分层。然而，最常用的模型并没有考虑 DV 房间内热负荷的类型和位置。因此，计算出的占用区域的空气温度可能与实际温度相差 2-3°C，这会导致热舒适性差以及通风和冷却系统的尺寸不足。在本研究中，提出了节点模型以提供一种简化技术来预测具有 DV 的房间中的垂直温度梯度。此外，针对典型的办公环境，研究了房间高度和室内热源位置的影响。在预测占用区温度方面，将测量数据与现有节点模型和提出的节点模型进行了比较。所呈现的节点模型展示了典型热负荷及其组合的温度梯度的准确计算。