太阳能热水器节能技术在住宅小区的应用

本文通过太阳能热水器的应用实例，介绍其性能，设计要点及安装过程中应该注意的问题。并指出太阳能热水器的节能效果十分明显。     

插式热管—玻璃真空管太阳能热水器的研制

本文介绍了插式热管－玻璃真空管太阳能热水器研制思路及主要的结构特点,性能参数。对集热元件热管－玻璃真空管的设计做了一般性阐述。     

如何选购全玻璃真空管太阳能热水器

全玻璃真空管太阳能热水器具有高效、节能。无污染、安全可靠、使用方便等特点,一年四季均能使用,越来越受到广大消费者的青睐。同时,广大用户也迫切需要了解如何选择和鉴别全玻璃真空管太阳能热水器的知识。为此,本文将有关玻璃真空管太阳能热水器的结构、选材等质量问题作一介绍。1外观质量及加工工艺鉴别太阳能热水器主要由保温水箱、支架、反射板和真空管组成,要求整体美观、外形轮廓流畅。支架应有足够的刚度和稳定性,支架与其它部分连接牢固。支架焊接处焊缝平整无夹渣;水箱外壳圆整、平滑、无划伤;端盖与水箱外壳连接处无明…     

平板型与真空管型太阳能热水器发展状况分析

分析了平板型太阳能热水器和真空管太阳能热水器的发展状况,对两种热水器的性能进行了比较,同时对它们的发展趋势做出了展望。     

储热式真空管太阳热水器

太阳热水器通常由太阳集热器和贮水箱两部分组成,而闷晒式热水器则将集热器与贮水箱合二为一,构成一种结构比较简单的热水器.若将真空管集热器与贮水箱合为一体,组成的太阳热水器称之为储热式真空管热水器,俗称真空闷晒式热水器.储热式真空管热水器既保留了真空管集热器固有的优良热性能,又可省去附加的贮水箱,其结构紧凑,安装使用方便,外形也比较美观.     

新型U型真空管阳台式太阳能热水器

在分析目前太阳能热水器产品安装及使用中存在问题的基础上,提出解决方法,开发了一款新型U型真空管阳台式太阳能热水器.介绍了目前太阳能热水器产品的构成与分类,详细分析了新型U型真空管阳台式太阳能热水器的原理、结构及特点,并对其热性能进行测试,结果完全符合国家标准,满足目前太阳能热水器市场的需求.     

新型U型真空管阳台式太阳能热水器

在分析目前太阳能热水器产品安装及使用中存在问题的基础上,提出解决方法,开发了一款新型U型真空管阳台式太阳能热水器。介绍了目前太阳能热水器产品的构成与分类,详细分析了新型U型真空管阳台式太阳能热水器的原理、结构及特点,并对其热性能进行测试,结果完全符合国家标准,满足目前太阳能热水器市场的需求。     

家用太阳能热水器集热管内外清洗装置

当太阳能热水器的集热管外蒙尘污、内带水垢时,其集热效果会明显降低。文章设计了清洗集热玻璃管外部尘污和玻璃集热管内部水垢的装置。擦洗集热玻璃管外部时,只要在室内按动开关即可自动完成;清洗玻璃集热管内部水垢时,不必拆卸集热管,也不须使用化学清洗剂。     

无芯水平热管真空管集热器及其在建筑中的应用

一引言太阳能利用已经成为建筑节能的一种有效措施。在民用建筑的热水供应系统中,采用各种形式的太阳能集热器加热生活热水是目前太阳能利用的主要形式之一。但因为建筑形式和建筑结构的复杂多样,特别是多高层住宅建筑的大量涌现,使得如     

Comparative study based on exergy analysis of solar air heater collector using thermal energy storage

This communication presents the comparative experimental study based on energy and exergy analyses of a typical solar air heater collector with and without temporary heat energy storage (THES) material, viz. paraffin wax and hytherm oil. Based on the experimental observations, the first law and the second law efficiencies have been calculated with respect to the available solar radiation for three different arrangements, viz. one arrangement without heat storage material and two arrangements with THES, viz. hytherm oil and paraffin wax, respectively. It is found that both the efficiencies in case of heat storage material/fluid are significantly higher than that of without THES, besides both the efficiencies in case of paraffin wax are slightly higher than that of hytherm oil case. Copyright © 2011 John Wiley & Sons, Ltd.     

Experimental investigation of a domestic solar water heater with solar collector coupled phase-change energy storage

Phase change materials (PCMs) have good properties such as high thermal capacity and constant phase change temperature. Their potential use in solar energy storage is promising. Tests of exposure and constant flow rate are performed to investigate the thermal performance of a domestic solar water heater with solar collector coupled phase-change energy storage (DSWHSCPHES). Due to the low thermal conductivity and high viscosity of PCM, heat transfer in the PCM module is repressed. The thermal performance of the DSWHSCPHES under exposure is inferior to that of traditional water-in-glass evacuated tube solar water heaters (TWGETSWH) with an identical collector area. DSWHSCPHES also performs more efficiently with a constant flow rate than under the condition of exposure. Radiation and initial water temperature have impacts on system performance; with the increase of proportion of diffuse to global radiation and/or initial water temperature, system performance deteriorates and vice versa.     

承压式真空管太阳集热器及其应用

承压式真空管太阳集热器(专利号：ZL98110385．5)是在集热器的联集管(或称联箱)中设置了二次换热器件，这种新型二次换热式全玻璃真空管集热器与目前常规的承压真空管集热器相比，成本大大降低，而且承压高，真空管不结垢，耐严寒(至-50℃环境温度)。这一突破不仅可以让水箱与集热器分离，     

Review on solar water heater collector and thermal energy performance of circulating pipe

The effect of thermal conductivity of the absorber plate of a solar collector on the performance of a thermo-siphon solar water heater is found by using the alternative simulation system. The system is assumed to be supplied of hot water at 50 °C and 80 °C whereas both are used in domestic and industrial purposes, respectively. According to the Rand distribution profile 50, 125 and 250 l of hot water are consumed daily. The condition shows that the annual solar fraction of the planning functions and the collector's configuration factors are strongly dependent on the thermal conductivity for its lower values. The less dependence is observed beyond a thermal conductivity of 50 W/m °C for the solar improper fraction and above 100 W/m °C for the configuration factors. In addition, the number of air ducts and total mass flow rate are taken to show that higher collector efficiency is obtained under the suitable designing and operating parameters. Different heat transfer mechanisms, adding natural convection, vapor boiling, cell nucleus boiling and film wise condensation is observed in the thermo-siphon solar water heater with various solar radiations. From this study, it is found that the solar water heater with a siphon system achieves system characteristic efficiency of 18% higher than that of the conventional system by reducing heat loss for the thermo-siphon solar water heater.     

太阳热水系统节能量计算方法探讨

针对太阳辐照量、用户热水用量随时间段变化的情况,提出了分时间段计算的用户全年热水需能量、太阳热水系统年产能量计算公式及太阳热水系统年节能量与节能率的计算公式,还提出了用太阳热水系统利用率来优化太阳热水系统的设计方法,有助于设计一个合理、高效的太阳热水系统,提高太阳热水系统的利用率及减少投资回收期.该计算方法也可供其他可...     

Performance analysis of a solar glass tube collector

The thermal performance and thermal processes of a glass tube collector have been analysed in this paper. Its thermal performance can be improved by changing the thermal processes to take advantage of the glass tube's ability to transmit sunlight; that makes it possible for the working fluid to directly absorb part of solar radiation. Its thermal performance is even better in most parts of the working region than that of a steel tube collector, even when the structure, meteorological conditions and thermodynamic properties of the working fluid are exactly the same.An equation of steady-state instantaneous efficiency of a glass tube collector has been derived in the paper. Calculations of various operating conditions have been made with a computer, and the calculated results are quite agreeable with the experimental results. Thus the equation and the calculation method can be used in the design of glass tube collectors and for comparison calculations. The calculations also show some other important features of a glass tube collector.     

Experimental analysis of evacuated tube solar air heater (ETSAH) with inbuilt sensible thermal energy storage

In the present work, an evacuated tube solar air heater (ETSAH) with inbuilt sensible heat storage material (SHSM) is experimentally evaluated. The system comprises two sets each having 50 evacuated tubes with an H-type arrangement and a total collector area of 16.92 m². For the purpose of hot air generation, ETSAH is simultaneously connected in series and in parallel with and without the use of reflectors. Three different mass flow rates of 122.90, 164.87, and 212.83 kg/h were fixed to get 12 diverse cases of ETSAH operation. The highest hot air temperature reported by the system is 121.7°C when it was connected in series with conventional reflectors at 212.83 kg/h of flow rate and 469 W/m² average solar intensity. The system reported an overall average energy efficiency of 49.76% and an exergy efficiency of 17.97% with the highest average hot air temperature difference of 56.12°C from 09:00 to 20:00 h. Without the incorporation of any additional SHSM, the average hot air temperature delivered by ETSAH (when under the neighbor building shadow) is 49.73°C logged from 17:00 to 20:00 h. The economic analysis is also carried out to ensure its practical application and feasibility. For the best system performance, the annual cost of hot air generation is 0.0194 Rs./kg (0.0002433 $/kg).     

Influence of collector plate temperature gradient on solar heater performance

This communication deals with the effect of a temperature gradient, due to difference in temperatures of sunlit collector surface and the surface in contact with the working fluid (heat exchanger fluid), on the performance of solar water heater. The analysis is not restricted to any particular configuration of solar heater. Experimental study of a spiral solar water heater confirms the theoretical prediction of thermal loss with temperature gradient.