共查询到19条相似文献,搜索用时 203 毫秒
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基于传热学理论,利用ANSYS有限元软件建立路面结构温度场分析的二维有限元模型,通过热稳态计算出路面基层温度场,再进行热瞬态分析,并通过回归方程预测了沥青路面的开裂温度。 相似文献
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框节点是建筑塑料门窗节能性能的关键,同时也是门窗构造设计的重点。本文依据《建筑门窗玻璃幕墙热工计算规程》(JGJ/T 151-2008)的计算方法,采用二维有限元模拟方法计算框传热系数、线传热系数等性能参数,制定相应的数据库管理方法、技术指南、技术论证和验证、持续的技术培训等建立我国目前唯一的型材节能数据库,并开发了数据库应用软件。 相似文献
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结构矩阵位移法实质上是将杆件结构离散化分成有限个单元,写出杆端单元的位移列阵、力列阵和刚度矩阵,建立刚度方程并用直接刚度法引入支承条件进行求解,编制有限分析计算程序,最后给出工程计算实例。 相似文献
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《Planning》2015,(2)
针对功能梯度材料物性参数随坐标变化的特点,基于Trefftz完备解提出了求解功能梯度材料热传导问题的有限梯度元方法。首先,利用变量代换推导出指数型、二次型和三角型功能梯度材料稳态热传导问题的Trefftz完备解;然后,利用Trefftz完备解对单元内部的温度场进行插值,构造出可自然模拟材料梯度属性的梯度单元,在该基础上建立混合Trefftz有限梯度元法求解功能梯度材料的稳态热传导方程;最后,采用混合Trefftz有限梯度元法对典型功能梯度材料板的温度分布进行数值模拟,以验证该方法的正确性和有效性。 相似文献
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采用二维稳态热传导模型和大型通用有限元分析系统ANSYS10.0对夏热冬冷地区三种不同保温系统组成的典型热桥进行计算和分析,得出了热桥外表面热流密度以及内、外表面温度和附加传热损失量的百分比,并对基于夏热冬冷地区气候特征的各种节能保温模式作出适宜性评价,为夏热冬冷地区节能保温模式的选择提供参考。 相似文献
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基于考虑温度和化学反应物浓度对化学反应速率影响的混凝土水泥水化反应放热模型,编制二维混凝土水化热温度场有限元分析程序。该程序通过控制各单元对整体刚度矩阵及整体荷载矢量列阵的贡献模拟大体积混凝土分层浇注时温度场的变化。根据单元参与组集情况对计算机内存实行动态分配,不但提高计算效率又可避免常规做法导致的整体刚度矩阵病态。将该程序用于桐柏抽水蓄能电站大体积混凝土基础的施工期温度场分析。计算结果表明,该方法能较好地反应混凝土施工期温度场的变化,同现场实测数据吻合较好。 相似文献
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建筑门窗玻璃幕墙是建筑围护结构节能最薄弱部位,其传热系数目前只能在实验室通过热箱法测定,在现场准确、快捷地测试该值对于建筑的节能评估改造具有重要意义。在现场测试门窗幕墙内外空气温度和表面温度的基础上,推导出了基于"准稳态"测试原理和"热阻法"、"表面温度法"、"传热系数法"3种传热系数现场测试方法,现场测试值与实验室检测值的较高一致性表明了该现场测试方法的准确性,连续测试数据与平均值的较小偏差表明了该测试方法的稳定性。研究结果表明,建筑门窗玻璃幕墙传热系数可通过该方法在现场准确、快捷地测试得到。 相似文献
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彭小云 《四川建筑科学研究》2012,38(2):275-278
建筑中庭具有玻璃幕墙和玻璃顶棚,热阻较小,透射系数较大,不利于夏季的防热和冬季的保温。通过计算分析,得出不同玻璃类型产生的中庭能耗。正确选择玻璃类型,可以降低建筑中庭的能耗,达到节能目的。结果可为中庭设计提供依据。 相似文献
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夏热地区热通道玻璃幕墙的热工数学模型 总被引:3,自引:2,他引:1
本文介绍了热通道玻璃幕墙的简单数学模型。模型的物理概念和Trombe墙相似。该幕墙由外侧单层和内层中空玻璃组成热通道。列出稳态状态下热通道的热平衡方程,通过线性矩阵求解了两个玻璃和通道内空气的半均温度,并使用热阻网络表达在太阳辐射条件下,热通道的传热过程。计算机模拟表明,夏热地区热通道幕墙内层中空玻璃的外表面温度较传统幕墙的表面温度有明显降低,由太阳透射引起的房间得热也有较大减少。 相似文献
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Glass breakage of curtain wall coverings during a fire can promote the spread of a fire in high-rise buildings. Prior to the development of sprinklers to prevent and delay glass breakage, it is necessary to identify the breakage mechanism of curtain wall glass panes and to establish a numerical model to simulate various fire situations using sprinklers to design effective sprinkler systems. The present study was conducted to establish a numerical model and analysis procedures to simulate fire situations. First, curtain wall was installed on one side of a testing chamber that was 3 m (L) × 3.2 m (W) × 2.4 m (H), and a free burning experiment was conducted using heptane. The same experimental conditions were simulated using a numerical model employing the modified volume heat source (MVHS) model. To analyze the validity of the numerical model, the air temperature inside the room and the surface temperatures of the curtain wall Al frame and glass panes calculated by numerical analysis were compared with experimental values, and the location and timing of the initial crack were compared. Thermocouples were installed on the Al frame and the glass surface to measure the surface temperature of the curtain wall during the fire for approximately 100 s after the onset of the fire. Additional thermocouples were installed to measure the air temperature inside the room to verify the results of the numerical analysis. A numerical model using the MVHS model was established to analyze the overall temperature distribution and the behavior of thermal stress on the curtain wall caused by the fire. MVHS calculations were based on measured fuel consumption, and the numerical analysis results were compared with the experimental values. We confirmed that the temperature calculated using computational fluid dynamics (CFD) was in good agreement with the temperature measured in the experiment. The temperature distribution and thermal stress of the curtain wall up to the point of glass breakage were reviewed using a thermal stress structural analysis that employed the results of the CFD analysis with MVHS. The time required to reach the temperature required for glass to break in the numerical analysis and the time required for the first crack to occur in the experiment were identical. The crack positions obtained from the numerical model and experiments were also the same. Overall, our results showed that the numerical model using the MVHS model is suitable for predicting curtain wall breakage and temperature distributions inside a space during the fire. 相似文献
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介绍了带遮阳百叶的热通道玻璃幕墙的简单数学模型。该幕墙由外侧单层玻璃幕墙和内侧中空玻璃幕墙组成热通道,通道中内置遮阳百叶以减少太阳能透射得热。在夏热地区,空气在通道中被太阳辐射加热,处于自然通风状态之下。列出了稳态条件下系统的热平衡方程,通过线性矩阵求解了太阳辐射和外界环境温度分别改变时,两个玻璃和通道内两个空气层及百叶的平均温度。计算模拟表明,内置遮阳百叶的热通道幕墙的内层中空玻璃的外表面温度较传统单层幕墙的表面温度有明显降低;与无遮阳百叶的热通道幕墙相比,室内透射得热量有很大减少,传热系数也比中空玻璃和无遮阳百叶的热通道幕墙有显著降低。 相似文献