【作者】 庄春龙；

【导师】 李百战；

【作者基本信息】 重庆大学 ， 土木工程， 2011， 博士

【摘要】 我国青藏高原北部地区驻扎着大量的分散式哨所、兵站及连以下分队住用营房。由于该地区冬季漫长,且十分寒冷,冬季供暖对设备、物质及燃料消耗的压力很大。许多分散式营房由于不适合采用节能效率较高的集中供暖方式,而主要采取燃油锅炉等独立供暖设施。一些哨所甚至没有采暖措施,严重时将危及部队官兵的生命安全。太阳辐射是对建筑室内环境影响最重要的因素之一,而青藏高原地区是我国太阳能资源最为丰富的地区。对于分散式哨所、兵站及分队住用营房的冬季采暖而言,提高建筑对太阳能的利用是十分重要的节能途径。地处该区域营房的交通条件较为艰险,建筑材料运输成本高,可施工工期短等情况,使施工质量难以得到很好的控制,且很难采用工程量大的传统建造方式。由于轻质建筑施工采用干法作业,建造速度快,近年来发展较为迅速,尤其轻型钢结构建筑,已成为国内外目前应用和发展较快的新型建筑结构型式。特别是一些有特殊要求的低层建筑,如部队营房哨所、兵站和大跨度建筑等,应用轻质建筑的优势更为明显。轻质围护结构虽具有保温隔热性能好的优势,但其蓄热性较低,建筑整体热工性能较差,室内温度波动大,基本上不能有效地利用太阳辐射热能用于改善室内热环境。因此,被动式太阳房设计中明确规定围护结构不宜采用轻质墙体材料。相变材料与显热蓄热材料(如混凝土、砖等)相比,由于蓄热密度高、重量轻,大副降低对建筑物构造和结构强度的要求,应用于轻质建筑,能够显著提高轻质墙体的蓄热性能。但目前相变材料应用于轻质建筑围护结构中,存在许多需待解决的问题,如:缺乏较为适宜的作为墙体结构的相变材料制备及特性研究;在满足使用要求的同时,如何确定与围护结构基体结合,易于施工建造的结构形式;针对相变材料墙体的蓄热、放热特性,如何确定其使用效果评价指标;以及应用于不同气候特征地区轻质建筑的设计理论研究及工程实践。基于上述对于相变材料在墙体中使用前景及存在问题的分析,结合被动式太阳房技术,论文开展了利用相变材料改善轻质哨所墙体热工性能和室内热环境的研究,主要内容如下:①进行相变轻质墙体非稳态传热过程分析及计算研究伴有相变的传热问题在数学上是一个强非线性问题,对于不同工况下的相变墙体传热过程将更加复杂。对这类情况使用近似方法求解较困难,而数值方法是处理这类问题较为有效的手段。通过对相变墙体传热特点分析,研究建立相变墙体传热过程解析方程,在此基础上建立基于有限差分法的相变墙体传热数值计算模型,为相变墙体设计和应用提供计算分析手段。②进行相变墙体被动式太阳房(Trombe形式)自然对流换热模拟研究对墙体含相变材料的轻质集热蓄热墙式(Trombe形式)被动太阳房进行传热模型及空气间层内自然对流换热的模拟研究,并对海拔较高地区建筑围护结构表面的对流换热系数及天空背景温度等参数进行了修正,建立了室内空气温度的计算程序。为相变轻质墙体被动式太阳房室内热环境模拟及室内温度的预测提供了理论基础和计算工具。③制备了新型相变材料,并完成相变轻质墙体结构设计和制备。采用溶胶-凝胶的工艺路线,以饱和脂肪酸为相变材料,制备二氧化硅为载体的复合相变材料。采用相变材料颗粒/板作为蓄热功能层、硅钙纤维板或轻质金属板等墙板材料作为结构支撑层、EPS等有机保温材料或无机保温材料作为保温功能层,完成多种“保温层+相变蓄热层+结构层”的轻质墙体结构设计和制备。④建立相变轻质墙体实验间,对模型的有效性进行验证在西宁地区建造了相变轻质墙体集热蓄热墙式(Trombe形式)被动太阳房实验间,对相变轻质墙体实验间围护结构内表面及室内温度进行测试,并与理论模型的计算结果进行对比验证。⑤提出了相变轻质墙体冬季采暖工况使用效果的评价指标结合相变轻质墙体的蓄热、放热特性及对室内温度的改善效果,确立了评价相变轻质墙体冬季采暖工况使用效果的指标:“累计日室内温度偏移值”I EX。⑥对冬季采暖工况的相变轻质墙体被动式太阳房技术进行优化用验证的数学模型对青藏高原北部地区轻质被动式太阳房进行相变墙体使用效果的优化分析,对影响相变轻质墙体被动式太阳房室内温度的参数进行多因素多水平优化模拟,总结出相变轻质墙体被动式太阳房优化技术方案。⑦指导实际的工程设计利用上述的理论分析结论,在西宁及玉树地区进行了相变轻质墙体工程试点,结果表明:相变材料克服了轻质结构墙体由于不能有效蓄热,而不宜应用于被动式太阳房设计建造的局限,极大地提高了轻质结构建筑对太阳能资源利用效率,使轻质建筑也可以应用被动式太阳房技术。总之,论文开展了利用相变材料改善轻质墙体被动式太阳房围护结构热工性能和室内温度环境的研究。建立了有关相变墙体传热和轻质被动式太阳房室内温度计算模型。提出了相变轻质墙体冬季采暖工况使用效果的评价指标。得出了相变材料在部分地区被动式太阳房上适用规律,并开展了工程实践。论文的部分结论对相变墙体在轻质建筑中进行合理的设计和应用,发挥最佳节能功效奠定了理论基础。更多还原

【Abstract】 A great deal of dispersible sentry, soldier barrack and unaided barracks quarter at the northern region of Qinghai and Tibet plateau; it is lengthy and extreme cold in winter. The consumption of equipmentses, materials and fuels for heating are very big in winter.Because of being unsuitable for the energy efficiency concentrated type heating way,many dispersible type barracks mainly adopt the independent fuel boiler heating facilities.Some sentry even do not adopt heating systems,which severity endanger the life safety of soldiers.The solar radiation energy is the most important influence factor to the building indoor environment.The northern region of Qinghai and Tibet plateau is most rich region for solar energy resources in our country, so it is a very important energy efficiency way to exploit the solar energy for heating in the dispersible sentry, soldier barrack and unaided barracks.Due to the scurvinessc transportation condition, high building material conveyance cost, and short construction period it is difficult to adopt the tradition construct way, also the construction quality has been hard to get a good control.The lightweight building has been developed quickly in recent years, particularly light steel structure building, which has become new building structure pattern to apply and develop currently at home and abroad. Due to having a quick construction speed, the well anti-vibration capability, less foundation expenses, beauty building shape, less building material and steel use, high recycle utilization advantage, the lightweight building extensively is used for kinds of industrial building, the civil building and public building. Especially in some low layers construct with a special request, the advantages of the lightweight constructs is more obvious, for example troops barracks sentry, the soldier barrack and greatly crosses building etc. But the lightweight constructs cannot attain the request of related building energy efficiency standard because the cumulate thermal capability of light weight structure is weak and whole thermal inertia is bad. Some scholars definitely have put forward that the common lightweight construct was unwell used for passive solar building technique.Because of the high cumulate thermal density and the light weight, compared with obvious thermal material (concrete and brick.etc.), the Phase Change Materia(lPCM) will reduce the request of construct and structure strength of building. Be applied to lightweight building fabric, PCM can increase the cumulate thermal capability of lightweight fabric and improves the thermal capability of lightweight constructs, and make the whole thermal inertia index to attain the request of energy efficiency standard. In the meantime it will be one of the effective paths that improve the indoor thermal environment quality in light weight building. Up to now, using PCM in building materials has been limited by many difficulty,such as: lack of the making and characteristic research on PCM appling to the fabric structure material; at the time of satisfying using request, how to make sure the fabric combinative form of easy construction; how to evaluate the effect of PCM using under different conditions, such as phase change material temperature, thickness, insulation thickness and night ventilation in different climate area and incorporating the PCM into the wallboard,lack of design theories research and engineering fulfillment at different weather characteristic region lightweight etc.According to above-mentioned analysis of foreground and existence problem for PCM using in the fabric, combining passive solar house technique the thesis developed the technique application study that utilize PCM to improve the fabric thermal characters and indoor temperature environment in lightweight building:①Build up the non-steady heat conduction mathematics model for phase change fabric, and carry on the numerical analysisHeat conduction of phase change is strong nonlinear mathematics problem; many literatures had already proven that there is no accurate solution for the kind of phase change heat conduction problem through the limited thickness flat panel of fabric. In the meantime the approximate method is more difficult to solve this kind of problem and inapplicable for engineering, but the numerical method is more effective means to handle this problem. The thesis analyzed the heat conduction characteristic for phase change fabric, established the mathematics models of the phase change heat conduction and indoor air heat balance of PCM room, ulteriorly dispersed the equations and carried on the numerical calculation with the limited different method, this work would provide the calculation and analysis means for the design of phase change fabric and building energy efficiency application.②Put up the research of nature convective heat transfer model for phase change fabric passive solar house(Trombe),and carry on the numerical analysisThesis had carried on the simulation researches on the heat transfer and air convective heat exchange in the PCM fabric trombe passive solar building, and builds the mathematic model on the air flow and heat exchange. Adopted the finite difference method to disperse the equations and solved the differential system of equations with the Semi-Implicit iterative Method.It could provide the credible theory and powerful calculative tools for stimulating and forecasting the indoor thermal environment of PCM lightweight fabric passive solar building.③Prepare new-style PCM and complete the structure design for PCM lightweight fabric.We had made the compound PCM of fatty acids and salts by the sol-gel method in this paper, which utilizes the silicon dioxide as the carrier. We had Adopted the PCM grain or plank as the cumulate thermal function layer, and the silicon and calcium fiberboard or lightweight metal plank as the wall structure support layer, and EPS and mineral thermal insulation material.etc.as the thermal insulation function layer, and finally had completed kinds of the cumulate thermal function layer + thermal insulation function layer + structure layer" structure design and making for fabric.④Establish PCM lightweight fabric experiment, carry on the identification for the usefulness of modelRespectively we had constructed the PCM lightweight fabric experiment chambers at Xining region (passive solar building condition in winter), test the inner surface and indoor air temperature in the lightweight fabric chambers, and carried on contrast verification with the calculation results of theories models.⑤Put forward the evaluation indexes for PCM lightweight wall usage effect on the condition of heat insulation and passive solar heatingCombining the characteristic of charging and discharging thermal capability of the PCM lightweight fabric and usage effect, we had established the usage effect evaluation indexes, that is the“Accumulative Excursion for Indoor Air Temperature in One Day—I EX”for passive solar heating on the PCM lightweight building.⑥Combining the passive solar energy technique, optimizing the structure form of PCM lightweight fabricUtilizing the mathematics model certificated, we had carried on the optimization analysis for applying the PCM passive solar technique in Xining zone. Carry on the simulation of many factors with many levels for the influence parameters on the indoor air temperature in the PCM lightweight passive solar building. Finally we had made sure the optimization structure forms of PCM lightweight fabric that could be applicable to the passive solar building in the the northern region of Qinghai and Tibet plateau. The optimization results could be as the passive solar building fabric design project.⑦Engineering designUtilizing the above-mentioned analytical results, we had constructed the PCM lightweight fabric building in Xining and Yushu, and analyzed and test the indoor thermal environment. The results had indicated that PCM can improve the indoor thermal environment quality in light weight building in winter, and improve the thermal capability of lightweight constructs, and attain the preferable effect of energy efficiency .In conclusion, the thesis developed the application study on making use of the PCM fabric to improve the thermal characteristic of fabric and indoor thermal environment in the lightweight passive solar building. Paper established the model of phase change heat transfer and the indoor air temperature thermal equilibrium. Put forward the evaluation index for PCM lightweight wall usage effect in passive solar building. The thesis carried on the scientific and exact analysis to the influence factors of the PCM application. Commanded the PCM apply regulation on the lightweight building fabric, and developed the engineering fulfillment. Parts of conclusions of thesis lay the initial theories foundation for carrying on reasonable design and application of PCM fabric in the lightweight passive solar building building and implementing the preferable economy energy effect.更多还原