反光板对提高热管真空管热性能的研究

提出了对带反光板的吸热体接收太阳辐射量的分析方法，并对三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的热性能，而且其吸热体的形状对热性能提高的幅度有影响。     

国内可再生能源文献信息

GN030501反光板对提高热管真空管热性能的研究.陶桢,何庆楠,李卫京,等.太阳能学报,2003,24(3):279～281.提出了对带反光板的吸热体接收太阳辐射量的分析方法,并对三种有渐开线反光板且吸热体不同的热管真空管和一种无反光板的热管真空管进行对比实验。结果表明:渐开线反光板可大幅度提高热管真空管的热性能,而且其吸热体的形状对热性能提高的幅度有影响。GN030502一种具有强化自然通风效果的太阳能空调房.代彦军,王如竹.太阳能学报,2003,24(3):283～289.提出一种依靠吸附制冷原理制冷,结合太阳能通风筒强化自然通风的太阳能空调房,其特点…     

真空管太阳能集热器

真空管集热器就是将吸热体与透明盖层之间的空间抽成真空的太阳能集热器。用真空管集热器部件组成的热水器即为真空管热水器。真空管按吸热体材料种类,可分为两类：一类是玻璃吸热体真空管,一类是金属吸热体真空管。热管式真空管是金属吸热体真空管的一种,它由热管、吸热体、玻璃管和金属端盖等主要部件组成。     

热管式真空管在高寒地区的应用

热管式真空管在高寒地区的应用王强真空太阳集热管按吸热体材料不同可以分为两大类，即玻璃吸热体真空管（或称全玻璃真空管）和金属吸热体真空管（或称玻璃金属真空管）。热管式真空管是金属吸热体真空管的一种形式，本文从其结构、原理出发，结合产品在我国高寒地区的...     

热管式真空太阳能集热管及其应用

热管式真空太阳能集热管(简称热管式真空管或热管真空管),是金属吸热体太阳能真空集热管的一种,具备了全玻璃真空管良好的集热和保温性能,以及平板式集热器金属的良好导热性和机械强度。它以热管作为核心传热原件,具有其他类型的太阳能集热产品不可替代的优势。热管真空     

弯曲吸热板热管式真空管集热器

弯曲吸热板热管式真空管集热器何梓平蒋富林李炜弯曲吸热板，顾名思义，即构成真空集热管的吸热板呈弯曲形状。这是北京桑达太阳能技术有限公司最近推出的一种新型热管式真空管集热器，它既保留了北京市太阳能研究所研制成功的平面状吸热板热管式真空管集热器的全部优点，...     

新V型内聚光CPC热管式真空管集热器的热性能

基于圆管型复合抛物聚光器(CPC)的研究,由于接受体和CPC反光板之间存在缝隙而造成大量漏光损失,设计了一种可以减少漏光损失和热损的新V型CPC反光板,并综合利用热管式真空管集热器的优越性,开发出一种新V型内聚光CPC热管式真空管集热器。首先给出了其设计结构,并对其进行传热分析,推导出该型集热器的集热效率、总热损系数的计算方法,再进行室外动态性能试验,测定了它的效率曲线,试验结果与理论计算值较符合。     

热管真空管太阳热水系统的设计

热管真空管是一种高效的太阳能集热元件，它具有工作温度高、承压能力大、耐冷热冲击、抗冰雹等独特的优点。热管真空管组成的太阳热水系统，运行可靠，安装方便，适应性强，深受用户欢迎。本文简要介绍热管真空管太阳热水系统的有关设计问题，供大家参考。１热管真空管太阳热水系统工作原理（１）热管真空管热管真空管的结构如图１所示。太阳光透过玻璃管照射在吸热板上，太阳选择性吸收膜将太阳辐射能转化为热能。吸热板吸收的热量迅速将热管内少量工质汽化，并迅速上升到冷凝端，放出汽化潜热后冷凝成液体，在重力作用下流回热管蒸发端。…     

太阳能真空管的发展方向

现在市场上的太阳能真空管如图1所示。Ⅰ型,就是现在普通的全玻璃真空管。其特点为:玻璃管吸收到的太阳热直接传给水,传热热阻很小。但是真空管内有水而带来的缺点:易冻坏,结水污,热效率低。为了使真空管内无水而发展的其他形式,如Ⅱ、Ⅲ、Ⅳ型。Ⅱ型,就是在普通的全玻璃真空管(Ⅰ型)内放置金属热管。其特点为:真空管内无水,玻璃管吸收到的太阳热通过超导的金属热管传给水。但是,由于玻璃管与金属热管之间的传热热阻太大,使玻璃管上的吸热涂层老是处于高温工况下,同时抵消了由于真空管内无水而带来的热效率的提高。Ⅲ型,就是金属吸热体的真…     

重力热管在真空管式热水器中的应用

本文从分析真空集热管的缺点入手,结合真空管太阳能热水器的特点,分析了重力热管的几种特性,并对其应用于真空管式太阳能热水器的可能性、必要性做了一些探讨。     

Performance simulation of a parabolic trough solar collector

A new analytical model for optical performance and a modified integration algorithm are proposed and applied to simulate the performance of a parabolic trough solar collector with vacuum tube receiver. The analytical equation for optical efficiency of each point at reflector is derived first, then the optical efficiency of the system is simulated by numerical integration algorithm. The cosine factor, receiver efficiency, heat loss and efficiency of conversion of solar energy into net heat energy at any time can be calculated with the program. The annual average efficiency is also simulated considering discard loss. The effects of optical error, tracking error, position error from installation of receiver, optical properties of reflector, transmittance and absorptivity of vacuum tube receiver on efficiencies of the trough system are simulated and analyzed as well as optical parameter.     

CPC热管式真空管集热器的集热效率研究

介绍了CPC(compound parabolic concentrator)热管式真空管集热器的结构,对CPC热管式真空管太阳能集热器进行了传热分析,并对CPC热管式真空管集热器、热管式真空管集热器和CPC热管式集热器的集热效率进行了对比计算。CPC热管式真空管集热器的集热效率的理论计算和试验结果表明:CPC热管式真空管集热器的集热效率最佳。     

Optical performance analysis and design optimisation of multisectioned compound parabolic concentrators for photovoltaics application

Currently, all compound parabolic concentrators (CPCs) for photovoltaic (PV) application consist of reflecting surfaces in the form of a parabolic shape. However, parabolic shapes create non‐uniform illumination on the PV module, which significantly reduces the power output. To achieve high‐concentration ratio and uniform illumination on the PV module, this study proposes the use of flat reflector sections in a symmetric two‐dimentional CPC instead of the parabolic shape. This collector is called multisectioned compound parabolic concentrator (M‐CPC). However, the main challenge in designing such a concentrating system lies in the determination of the optimal number of flat sections and the width of each section so that the optical properties of the M‐CPC approaches that of the standard CPC. In this work, seven M‐CPCs having the same designing parameters but with different total number of flat reflector sections were designed. A detailed analysis of the optical performance was undertaken to optimase the M‐CPCs. The optimal design was based on‐high angular acceptance, low‐optical losses, high‐optical efficiency in a wide‐interval incidence angles, and uniform energy flux distribution on the PV module. Results from the ray trace simulation analysis show that the optimal M‐CPC is the design with a total number of seven flat reflector sections (ie, M‐CPC7). This design has high‐angular acceptance (100%) in a wide‐interval incidence angles, low‐optical losses (7%), and high‐optical efficiency of about 95% in a wide‐interval incidence angles. In addition, M‐CPC7 illuminates the PV module more uniformly than the standard CPC.     

CPC type integrated collector storage systems

Integrated collector storage (ICS) solar water heaters with stationary compound parabolic concentrating (CPC) reflectors are designed and test results are presented. The systems consist of single and double cylindrical horizontal tanks properly placed in truncated symmetric and asymmetric CPC reflector troughs. The suggested designs aim to achieve low cost systems with improved performance by the reduction of their thermal losses and the increase of water temperature rise by using the non-uniform distribution of solar radiation on the absorber surface. Four experimental models were constructed and tested outdoors to determine their mean daily efficiency and thermal losses during the night. Test results showed that asymmetric CPC reflectors contribute to lower thermal losses and the two connected in series cylindrical storage tanks result in effective water temperature stratification. The system with the single cylindrical storage tank and the symmetric CPC reflector performs satisfactorily during the day as well as during the night and regarding its simpler design it could be considered cost effective among the studied ICS systems. A typical thermosiphonic system with flat plate collector was tested for performance comparison, by which the improved daily efficiency of ICS systems and also their moderate water storage heat preservation during the night were confirmed.     

Thermal performance of linear Fresnel reflecting solar concentrator with trapezoidal cavity absorbers

Thermal performance of the four identical trapezoidal cavity absorbers for linear Fresnel reflecting solar device were studied and compared. The absorbers were designed for operating in conjunction with a prototype Fresnel solar reflector. Rectangular and round pipe sections were used as absorber by placing in the trapezoidal cavity. The absorber pipes were coated with ordinary dull black board paint and black nickel selective surface. The bottom of the cavity was provided with plane glass to allow the solar radiation to be reflected from the Fresnel reflector. The other three sides of the cavity absorber were insulated to reduce heat loss. Thermal performance of the Fresnel reflecting concentrator with each trapezoidal cavity absorber was studied experimentally at different concentration ratio of the reflector. The study revealed that the thermal efficiency was influenced by the concentration ratio and selective surface coating on the absorber. The thermal efficiency decreased with the increase in the concentration ratio of the Fresnel reflecting collector. The selective surface coated absorber had a significant advantage in terms of superior thermal performance as compared to ordinary black painted absorber. The round pipe (multi-tube) receiver had higher surface area to absorb solar energy as compared to rectangular pipe receiver. Thermal efficiency of the solar device with round pipe absorber was found higher (up to 8%) as compared to rectangular pipe absorber.     

CPC内聚光式热管集热管温度特性研究

为提高太阳能热水系统的输出温度,将CPC聚光技术应用于热管式真空集热管中,开发了一种新型的CPC内聚光式热管集热管。对该集热管建立数学模型,模拟计算其传热过程,获得了导热肋片温度、热管冷凝段温度等参数随太阳辐射强度的变化规律,并通过试验验证了数学模型的可靠性;与常规热管式真空管集热管传热特性相对比,证实了该集热管可大幅提高太阳能热水器输出温度。     

开放式热管中温太阳能空气集热装置的试验研究

设计一种使用简化CPC(非追踪式复合抛物线聚光板)集热板和新型开放式热管组合的全真空玻璃集热管中温太阳能空气集热装置。每个集热单元包括一个简化CPC集热板,一根全真空玻璃集热管,在玻璃集热管内安装一个铜管和外部的一个蒸汽包连接构成一个开放式热管结构。蒸汽包内安装螺旋换热管加热通过换热管的流动空气工质。分别使用水和CuO纳米流体作为热管工质,以空气作为集热工质,对热管式中温空气集热器的传热特性进行了实验研究。分析了不同工作压力、不同工质及纳米流体质量分数对热管集热传热特性的影响,详细比较了热管水工质和纳米流体工质在集热传热性能上的优劣。试验结果表明:本系统只使用2根玻璃集热管构成集热器,空气最大出口温度在夏天可达到200℃,在冬天可接近160℃,系统平均集热效率达到0.4以上,整个系统表现了良好的中温集热特性。以纳米流体为工质的热管热阻比以水为工质时平均降低了20%左右     

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。     

两种太阳能集热器的瞬时效率对比分析

对强制循环全玻璃真空管太阳能热水系统和强制循环热管式真空管太阳能热水系统的瞬时效率进行了对比分析,发现全玻璃真空管热水系统的效率曲线的斜率大于热管式真空管热水系统,这说明两种热水系统在运行温度相同时,热管式真空管的热损失较小,瞬时效率较高,有较好的高温特性和保温特性,并且热管式真空管太阳集热器的集热效率波动较小,能稳定在较高的水平。