PVT/相变吊炕传热特性及其与室内热环境的相互作用

As a popular space heating mode in north rural houses in winter, the traditional Chinese kang has many disadvantages including huger conventional energy consumption, severe air pollution, larger temperature maldistribution of kang plate, lower indoor air temperature and poor air quality. This study proposes a novel phase change elevated kang with solar photovoltaic thermal module, with solar photovoltaic thermal module as heat collection unit, phase change material as heat storage unit, upper and lower kang plate as heat discharge unit and electric heating module as supplementary heat unit. In this study, the basic research of heat transfer characteristic of the elevated kang will be studied by using the comprehensive method of theoretical analysis, numerical calculation and experimental investigation. The main work is divided into the following parts: (1) heat transfer principle and influence factor analysis; (2) dynamic heat transfer characteristic and its reaction with indoor thermal environment; (3) heat transfer optimization upon thermal comfort demand of human body. The findings of this study will provide theoretical basis for the application of the PVT/elevated kang in northern rural houses.

作为北方农村住宅中应用较为广泛的一种冬季供暖方式，传统火炕具有常规能源消耗大、环境污染严重、炕表面温度分布不均匀、室内空气温度偏低和空气品质差等问题。本课题提出一种基于太阳能PVT组件的无储热箱的相变吊炕，以太阳能PVT组件作为集热单元，以相变材料作为蓄热单元，以上、下炕板作为放热单元，以内置于上炕板的电加热模块作为辅热单元。本课题拟采用数值模拟和实验研究相结合的方法对相变吊炕的蓄散热特性进行研究。主要研究内容包括相变蓄热吊炕传热机理及其影响因素分析，相变蓄热吊炕的非稳态蓄散热特性及其与建筑热环境的相互作用，并以此为基础，研究基于人体热舒适性需求昼夜差异的相变吊炕的蓄散热特性优化。本课题的研究成果将为PVT/相变吊炕在北方农村住宅的应用提供理论基础。

采用炕进行采暖仍旧是北方农村住宅较为广泛使用的冬季供暖方式。本课题提出了一种新型的相变吊炕形式并开展了以下研究工作：（1）建立了相变吊炕与室内热环境的数值模拟模型，分析了相变温度、相变潜热和、管路流量和单/双侧放热形式对相变吊炕的蓄放热特性的影响规律。与单侧放热炕相比，在人体睡眠时间内双侧放热炕的被褥温度波动较小，能够维持在29~34℃之间。（2）研究了相变吊炕的传热特性与室内热环境的相互关系，并探讨了相变吊炕的地区适宜性。哈尔滨、北京和银川的太阳能贡献率分别为49.9%、70.1%和76.5%，太阳能热水相变炕在我国北方多地区均具有良好的效果。（3）制备了高导热系数的复合相变材料，搭建了相变吊炕的实验平台，研究了相变吊炕的实际传热特性与采暖效果。炕表面具有较好的温度均匀度，炕体的蓄热可为人体睡眠提供了良好的热舒适性，同时可以减少室内空气的温度波动，提高室内的热舒适度。（4）通过开展人体睡眠实验，分析了相变吊炕所形成睡眠夜环境的舒适性。人体睡眠微环境的温度依然可以较长时间维持在28℃至30.8℃的温度范围内，相变吊炕可以较好的保障人在夜间的睡眠微环境热舒适性。本课题的研究成果将为提高相变吊炕在北方农村住宅的采暖效果与舒适性提供了理论基础。