连栋玻璃温室采暖热负荷计算方法

采暖热负荷是温室采暖系统设计中最基本的参数,为了研究随着内保温幕等设备的普及应用和温室密闭性的改善,现行标准体系下计算出的温室热负荷是否仍旧适用,该研究比较了中国和美国的共6个标准中的采暖热负荷计算方法,并以北京地区连栋玻璃温室为例进行采暖热负荷的定量分析。研究表明,基础墙传热热损失约占围护结构总热损失的0.1%,地面热损失占温室总热负荷的1%左右,两者均不是影响温室采暖热负荷的主要因素。计算表明,按照6个标准分别计算出的温室单位面积采暖热负荷最小为230.10 W/m²,最大为305.24 W/m²,相互之间差异较大,而且与温室实际配置散热器的散热量139.61 W/m²相比整体存在明显差距。在考虑内保温幕保温作用后温室的单位面积采暖热负荷最小为101.56 W/m²,最大为176.69 W/m²,如剔除中国民用与工业建筑中由于没有考虑玻璃拼缝造成冷风渗透热损失偏低的最小值,温室专用标准的热负荷计算方法基本符合实际情况。为此,研究提出在温室采暖热负荷计算中应充分考虑温室保温幕...

Methods for calculation of heating load in gutter-connected glasshouse

Heating load is the most basic parameter in the design of greenhouse heating system. The calculated heating load directly affects the equipment configuration of the heating system. If it is too small, it can not meet the design requirements. If it is too large, it will increase the initial investment and is not conducive to the efficient operation of the system. Climate screens have been widely used in China since the 20th century, and have become the standard configuration of greenhouse. In order to study whether the greenhouse heating load calculated under the current standard system is still applicable with the popularization and application of equipment such as internal climate screens and the improvement of greenhouse air tightness, this study compares the calculation methods of heating heat load in six standards of China and the United States, and takes a multi span glass greenhouse in Beijing as an example quantitative analysis of heating load. It is found that the heat loss of the sill wall accounts for 0.1% of the total heat loss of the enclosure structure, and the ground heat loss accounts for about 1% of the total heat load of the greenhouse, neither of them is the main factor affecting heating load. The results show that the minimum heating load per unit area of greenhouse is 230.10 W·m-2 and the maximum is 305.24 W·m-2, which is quite different from each other. Moreover, compared with the actual heat capacity of radiator 139.61 W·m-2, there is a significant difference between them. Analyze the reasons, the former is due to the fact that the heat loss of cold air infiltration calculated by gap method in civil and industrial buildings in China does not consider the glass splicing gap, which makes the calculation value of heating heat load of greenhouse obviously low; the latter is due to the fact that all the calculation standards of heat load do not consider the influence of climate screens on greenhouse insulation. The minimum heating load per unit area of the greenhouse is 101.56 W·m-2 and the maximum is 176.69 W·m-2 after considering the effect of internal climate screens. If we get rid of the minimum value of low heat loss of cold air infiltration caused by glass joint in Chinese civil and industrial buildings, the calculation method of heating load in greenhouse special standards basically conform to the actual situation. Therefore, it is suggested that the effect of internal climate screens should be fully considered in the calculation of heating load of greenhouse, and the heat loss of cold air infiltration should be calculated according to the method of ventilation rate rather than the gap method. The results provide a scientific, accurate and standardized basis for heating load calculation of multi span glass greenhouse in China.