真空玻璃盖板热管平板式太阳能热水器的研制

介绍了研究成功的采用真空玻璃盖板的热管平板式太阳能热水器,测试了其性能,并与全玻璃真空管太阳能热水器和蜂窝热管太阳能热水器进行了比较。实测得到,真空玻璃盖板热管平板式热水器的日平均效率比后两分别大13．3％和6．5％,平均热损系数比后两分别小52．5％和21．5％。真空玻璃盖板平板式太阳能热水器性能优越,有很好的应用前景。     

热管工质量的探究

众所周知，热管具有诸多优良特点，如均温性、热流密度可以变化、热二极管特性等，因此它在太阳热水器领域具有广阔的应用前景。目前我国太阳能应用中热管技术主要集中在民用热水器上，如平板式热管太阳热水器和热管真空式太阳热水器，但由于技术和价格方面的原因，这两种热管式太阳热水器并未得到最大限度的普及，而热管中的工质量问题就是热管技术中的一大难题。本人多年来从事热管技术开发与研究，并对热管中的工质量问题进行过一些技术性的探究。现阐述几点看法，愿与同仁共同商讨。     

怎样提高真空管式太阳热水器日平均热效率

衡量太阳热水器热性能的重要指标之一是日平均热效率，日平均热效率越高，相同条件下整机有效得热量就越大。我们知道平板式太阳热水器日平均热效率大都在60％以上，而全玻璃真空管太阳热水器日平均热效率只有45％（国标）左右，问题出在哪里呢？     

热管式真空管太阳能集热器研制成功

热管式真空管太阳能集热器研制成功１９９４年９月２０日，北京市太阳能研究所研制生产的热管式真空管太阳能集热器通过鉴定，标志着我国太阳能热利用基础元件的研究与生产步入世界先进行列。集热器是太阳能热利用领域中最关键的基础部件，它的发展经历了问晒式、平板式、...     

玻璃真空管内插热管式太阳热水系统热性能研究

对玻璃真空管内插热管式太阳集热系统的结构特点和热性能进行了研究.通过理论分析和热性能实验,对两种热水器的日有用得热量、平均热损因数进行了分析研究,并将实验数据用最小二乘法拟合,得出较为理想的热性能曲线.理论分析与实验结果表明:玻璃真空管内插热管式热水器与全玻璃真空管式热水器相比,日有用得热量高、平均热损因数小、热容小,具有较好的高温效率特性和保温特性,为其在太阳能膜蒸馏系统上的应用研究奠定了基础.     

二次换热平板型太阳能热水器的热性能研究

对夹层换热器的传热效率和总传热系数以及带夹层换热器平板型太阳能热水器的热性能进行测试与分析,对比分析三种热水器的平均日效率和平均热损系数。测试结果表明,夹层换热器的换热效率都在85%以上,一天中的平均总传热系数(UA)hx为88.16 W/K;带夹层换热器的平板太阳能热水器的平均日效率为49.8%,低于普通平板太阳能热水器的平均日效率(53.4%),但要高于全玻璃真空管太阳能热水器的平均日效率(48.7%)。     

全自动太阳能重力热管真空灌装系统的设计

太阳能重力热管真空灌装技术是太阳能重力热管热水器的关键技术,而传统热管工质液的灌装以手工为主,其工质液的灌注精度、热利用率、热管寿命以及生产效率等都存在不足。本文针对这些不足,通过调查法和实验法等多种手段,研究出了一种全自动太阳能重力热管真空灌装系统,结果表明,该系统可有效克服这些不足,达到较好的节能效果。     

专利信息：太阳能热利用

分体壁挂式太阳能热水器　专利申请号：200420049475.1　公开号：CN2746320 申请人：北京民意伟业太阳能热水器有限公司；真空玻璃盖板热管平板式太阳能热水器　专利申请号：200420037758.4　公开号：CN2747519 申请人：浙江大学；窗帘式太阳能热水器　专利申请号：200420110275.2　公开号：CN2740965　申请人：上海市明中学；防爆太阳能全玻璃真空集热管　专利申请号：200410012193.9　公开号：CN153847　申请人：王恒月　黄永年；     

平板式与真空管式太阳热水器热性能分析比较

在太阳热水器中依据吸热体的形状,可将其分为平板式太阳热水器和真空管式太阳热水器两大类。由于吸热体形状的不同,导致这两类热水器在热性能上各有差异。在家用太阳热水器热性能测试的国标中,热性能指标主要有日平均效率η d、平均热损系数 UL和非稳态效率方程。其中,日平均效率η d描述了在正常天气状况 (晴天 )下,一日内在热水器采光面上接收到的太阳辐射量中转化为提高水箱水温的热量的百分比;平均热损系数则反映了在无日照等条件下,热水器整体的保温性能;而非稳态效率是上述的热转换效率在不同时点的体现,非稳态效率方程则是…     

以太阳模拟器为光源的集热器室内稳态性能对比

以大面积太阳模拟器考察了平板式太阳能集热器、热管真空管式太阳能集热器、全玻璃真空管式太阳能集热器室内稳态下的性能。经测定,全玻璃真空管式太阳能集热器的时间常数为1235 s,其压力曲线随流速变化平缓。在辐照强度为900 W/m2、进口温度低于57℃时,平板太阳能集热器的效率高于热管真空管式和全玻璃真空管式太阳能集热器;进口温度高于57℃时,式真空管式太阳能集热器的效率高于平板式太阳能集热器;进口温度高于64℃时,全玻璃真空管式太阳能集热器的效率高于平板式太阳能集热器。在工作温度范围内,全玻璃真空管式太阳能集热器的效率低于热管真空管式太阳能集热器。设计、流动和换热特征影响了集热器的性能。     

三维立体式太阳热水器及其集热盲区

文中给出了三维立体式太阳热水器，并由实验证明了三维立体式太阳热水器的热效率高于平板型太阳热水器，同时给出了在不同纬度地区的集热盲区的计算方法。要提高热效率，必须避开集热盲区。     

Experimental investigation on thermal performance of thermosyphon flat-plate solar water heater with a mantle heat exchanger

The thermal performance of thermosyphon flat-plate solar water heater with a mantle heat exchanger was investigated to show its applicability in China. The effect on the performance of the collector of using a heat exchanger between the collector and the tank was analyzed. A “heat exchanger penalty factor” for the system was determined and energy balance equation in the system was presented. Outdoor tests of thermal performance of the thermosyphon flat-plate solar water heater with a mantle heat exchanger were taken in Kunming, China. Experimental results show that mean daily efficiency of the thermosyphon flat plate solar water heater with a mantle heat exchanger with 10 mm gap can reach up to 50%, which is lower than that of a thermosyphon flat-plate solar water heater without heat exchanger, but higher than that of a all-glass evacuated tubular solar water heater.     

集热方式对全玻璃真空管太阳能热水器性能的影响

为对比分析自然循环竖排管、强制循环竖排管和强制循环横排管3种集热方式对全玻璃真空管太阳热水器有效集热量、平均有效集热效率和瞬时有效集热量等的影响,以3组30支Φ58×1800 mm的全玻璃真空管太阳热水器为研究对象,在兰州地区搭建试验平台,在太阳辐射为19.0~25.7 MJ/m²,风速为0.5~1.3 m/s,平均环境温度为8.9~12.0℃的情况下进行连续5 d的试验。试验结果表明:自然循环竖排管热水器有效集热量和平均有效集热效率比强制循环竖排管热水器分别高6.6~8.3 MJ、10.8%~14.8%;强制循环竖排管热水器有效集热量和平均有效集热效率比强制循环横排管热水器分别高0.9~3.4 MJ、1.6%~5.0%。从有效集热面积、真空管内部换热强度、循环管道热损失共3个方面解释不同集热方式产生差异的原因。     

家用太阳热水器热性能试验方法及标准探讨

对家用太阳热水器热性能的评价方法进行了分析,国标中采用“平均日效率”反映热水器的热性能有一定局限性,“平均热损系数”定义的物理含义不清晰,数学表达式的推导也值得商榷。国标中提出的测定水箱平均水温的方法对不同种类的热水器及不同种类的水箱会带来不易控制的误差。     

提高太阳能集热器热性能的实验研究

在能量平衡方程的基础上,以《家用太阳热水器热性能试验方法》（GB／T12915—1991）为依据,对两种有渐开线反光板且吸热体形状不同的热管真空管和一种无反光板的热管真空管进行了对比实验。结果表明,渐开线反光板可大幅度提高热管真空管热水器的日平均效率,加反光板且吸热体为圆柱形的集热器能够达到更好的效果。     

Session D: Co-products/Animal Feed 2. Energy Related Aspects for Fuel Ethanol Production

In this paper, various ways for improving the thermal performance of heat pipe solar water heaters were provided based on the heat transfer analysis and have been improved by experiments and practical use. It is shown that the increase of the heat transfer space of heat pipe condensation section is the effective way to improve the instantaneous efficiency of heat pipe solar water heater, and the increase of L/D ratio of heat pipe is also important for improving its whole day performance.     

Experimental studies of a new solar water heater system using a solar water pump

The research goal was to develop a new solar water heater system (SWHS) that used a solar water pump instead of an electric pump. The pump was powered by the steam produced from a flat plate collector. Therefore, heat could be transferred downward from the collector to a hot water storage tank. The designed system consisted of four panels of flat plate solar collectors, an overhead tank installed at an upper level and a large water storage tank with a heat exchanger at a lower level. Discharge heads of 1, 1.5 and 2 m were tested. The pump could operate at the collector temperature of about 70–90 °C and vapor gage pressure of 7–14 kPa. It was found that water circulation within the SWHS ranged between 12 and 59 l/d depending on the incident solar intensity and system discharge head. The average daily pump efficiency was about 0.0014–0.0019%. Moreover, the SWHS could have a daily thermal efficiency of about 7–13%, whereas a conventional system had 30–60% efficiency. The present system was economically comparable to a conventional one.     

Experiments of a solar flat plate hybrid system with heating and cooling

Based upon the prior research of the solar hybrid water heater and refrigerator, a new flat plate solar hybrid system with heating and cooling was proposed and experimental prototype device was constructed. With this new hybrid system, the heat and mass transfer can be improved effectively both in desorption process and adsorption process. The conventional flat plate solar water heater collector absorber is immersed inside adsorbent bed in the new hybrid system. The experimental results show that not only the cooling effect can be obtained, but also both the sensible heat of the adsorbent bed and the adsorption heat can be recovered effectively to produce hot water for domestic use. The COP of this new flat plate hybrid system can reach 0.11 and the heat efficiency is about 0.45, this achievement has demonstrated an efficient way of the application of solar energy.