寒区路基热负荷时序特性及区域统计分析

TIME-SEQUENCE CHARACTERISTICS AND REGIONAL STATISTICAL ANALYSIS OF HEATING LOAD OF EMBANKMENT IN COLD REGIONS

  • 摘要: 为保证路基供热防冻胀系统的合理设计和节能运行控制,发展一种基于建筑热环境设计模拟工具包DeST(designer’s simulation toolkit)的寒区路基动态热负荷预测方法。在DeST软件中建立由一系列“路基微元”构成的计算模型,利用软件内置的气象模型、遮挡模型、光照模型模拟路基所处的气候环境、太阳辐照和地形条件;应用建筑分析模拟模块BAS(building analysis simulation module),通过状态空间法求解路基微元基础温度,通过预测值与实测值的校核保证计算精度;设置路基目标温度,完成热负荷的逐时计算。依托哈齐高铁DK221+150监测断面实测数据,对所述方法进行验证,结果表明,路基温度场计算值与实测值一致。案例路基的最大热负荷为945 W/m,冻结期平均热负荷为335 W/m。热负荷可以反映路基阴阳坡效应和沿深度的传热滞后效应。基于中国严寒和寒冷气候区23个城市的典型气象年数据,对高铁路基的热负荷进行区域统计分析,结果表明,最大热负荷范围为531 W/m~1338 W/m,并与纬度呈线性正相关关系。研究成果可为寒区路基冻害评价和供热方案设计提供参考。

     

    Abstract: Based on the Designer’s Simulation Toolkit (DeST), a method for predicting the dynamic embankment heating load in cold regions are proposed. A model composed of a series of 'micro elements' is first established, and the meteorological, shielding, and illumination models are used to simulate the climatic environment, topographic conditions, and solar radiation of the embankment, respectively. The state space method in the Building Analysis Simulation (BAS) module is then used to determine the initial temperature. The accuracy of the calculation is increased by setting the similarity threshold between the predicted value and the model training data. The heating load is identified by setting the target temperature. As a case study, the method is applied to the DK221+150 section of the Harbin-Qiqihar high speed railway. The results show consistency between the calculated and measured temperatures. The maximum and average heating loads are 945 W/m and 335 W/m, respectively. The method reflect the effects of both slope exposure to solar radiation and the lag in heat transfer inside the embankment. The data for typical meteorological years of 23 cities positioned in cold and severely cold climate zones in China are selected for a regional statistical analysis of the heating load of a high-speed railway embankment. The results show a maximum heating load of 531~ 1,338 W/m and a linear positive correlation between heating load and latitude. The results of this study can guide the evaluation of embankment frost state and the design of heating schemes in cold regions.

     

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