新型无水箱相变蓄热式太阳能集热器及热性能研究

设计了一种新型无水箱相变蓄热式太阳能集热器,其主要由太阳能真空集热管、相变储热球、电加热棒和换热管道组成。实验以复合三水醋酸钠为相变材料,进行无水箱相变蓄热式太阳能集热器的热性能研究,结果表明:在总容积为34 L的集热管组中添加20%的相变储热球后,管内单位容积蓄热量增加,总蓄热量达8.2 MJ;放热过程高温段延长,放热量增加1.98 MJ,有效放热率为0.81;经夜间保温测试,集热管组温降率为1.4℃/h。     

结合太阳能空气集热器的定形相变蓄能地板采暖系统实验研究

提出了一种与太阳能空气集热器结合的定形相变蓄能地板采暖系统充分利用太阳能.白天,由太阳能空气集热器加热后的热空气通过保温管道输送到相变地板夹层,相变材料(PCM)蓄热;夜间,房间的冷空气进入相变地板夹层,被加热后送入房间,相变材料放热.可行性实验研究表明,此采暖系统安全可靠,能显著提高窒内温度,房间各处受热均匀,热舒适性较好,有一定的应用前景.     

曲面太阳能集热器与平板太阳能集热器的性能对比实验研究

目前传统的平板太阳能集热器存在占地面积大、集热性能差等缺点,在一定程度上制约了其在中国的推广及应用,而新型的曲面太阳能集热器的集热性能有大幅提升。通过实验平台测试了曲面太阳能集热器与平板太阳能集热器在2种安装角度时的集热性能,并分析了这2种太阳能集热器的集热性能差异。结果显示,在相同安装角度时,曲面太阳能集热器的集热效率高于平板太阳能集热器的。     

真空管太阳能集热器研究进展

随着太阳能热利用需求的日益增长,真空管太阳能集热器的相关研究得到广泛关注.本文针对空气式真空管太阳能集热器,概述了集热器结构和相变材料对系统热效率的影响,及相变材料与集热器的组合方式,总结了真空管集热器应用中存在的问题,提出了通过改进组合结构以及增加换热面粗糙度提高相变蓄热性能将是重点研究方向.     

相变蓄热U型真空管太阳能集热器热性能研究

建立相变蓄热U型真空管太阳能集热器三维传热数值计算模型,研究工质流动时相变材料对U型真空管集热器热性能的影响,与无相变U型真空管集热器进行对比,探讨相变材料主要物性参数和工质质量流量对其热性能的影响规律.结果表明,在U型真空管集热器中填充相变材料可有效降低U型真空管集热器的出口温度峰值,相变材料在夜间及太阳辐射较弱时释...     

新型热管式真空管太阳能集热器

分析了新型热管式真空管太阳能集热器的开发背景，介绍了其工作原理，对集热元件、集热盒内关键零件的结构和特点以及产品的固定安装、连接方式进行了详细说明，同时提供了产品热性能测试报告和工程应用实例。     

新型热管式真空管太阳能集热器

分析了新型热管式真空管太阳能集热器的开发背景,介绍了其工作原理,对集热元件、集热盒内关键零件的结构和特点以及产品的固定安装、连接方式进行了详细说明,同时提供了产品热性能测试报告和工程应用实例.     

蓄能型空气式太阳能集热器热效率研究

针对以水为传热介质真空管太阳能集热器存在的低温冻裂、过高温炸裂和使用间断性等问题,将太阳能集热器的真空管进行改进设计,并在其中设置相变蓄能棒,采用空气为传热介质,研制了一种新型空气式太阳能集热器。实验测试表明：在平均辐照强度为727 W/m2条件下,可延长供热3 h,并随着辐照强度增加供热时间延长;无相变材料的真空管太阳能集热器平均集热效率为36%,相变蓄能棒平均等效集热效率为60%,新型蓄能型空气式太阳能集热器综合集热效率为96%;与传统以水为介质的内插式真空管太阳能集热器平均集热效率为58%相比,该新型集热器集热效率有显著提高。     

热管技术应用于太阳能平板集热器的研究

介绍了将热管技术应用于平板集热器,以克服其易冰冻、管内结垢、腐蚀等常见问题,论述了设计中需关注的影响因素,并针对热管及翅片的结构优化、加工工艺等进行了探讨.     

铝幕墙板太阳能集热器的性能研究

研制了一种铝幕墙板与集热元件一体化的新型太阳能集热器,并通过所搭建的测试平台对其集热性能及隔热特性进行了测试研究。通过实验测试,对该集热器在不同工况下的集热性能、隔热特性及其影响因素进行了系统分析,得出了集热器的累积集热量、集热效率、隔热特性等性能评价参数。测试结果表明,铝幕墙板太阳能集热器的平均集热效率为23%,隔热性能优于普通铝幕墙板。该装置具有太阳能集热及隔热功能,为建筑高效利用太阳能,实现太阳能与建筑一体化提供了一种新的工程应用模式。     

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.     

Experimental study on house cooling and heating with solar energy using flat plate collector

The OSE Project aims at developing the technology to utilize solar energy for heating, cooling and hot water supply on the basis of various technology for energy conservation in buildings. For the first step of this project a solar heating and cooling system with flat plate collectors and absorption refrigeration machine was installed in a house in 1974. This paper reports outlines of the system and operating results.     

全流道式平板型太阳能集热器的试验研究与模拟分析

以全流道式平板型太阳能集热器为研究对象,首先进行了集热性能试验测试,在此基础上,利用CFD技术对不同排管管径全流道吸热板内传热介质的流动与传热进行模拟。试验结果表明,全流道集热器集热性能好、保温性能优,最高瞬时集热效率可达86.1%,热损失系数仅为4.179 W/(m~2·℃);与有关国家标准比较,最高瞬时集热效率高14.1%,热损失系数低1.82 W/(m~2·℃)。模拟结果表明:全流道板芯在增大流体传热接触面积的同时产生了横向导流作用,使各排管间流体流量分布更为均衡;全流道板芯热阻小,壁面上热流分布均匀,有效地增大了板芯的对流换热。     

Optimization of a wickless heat pipe flat plate solar collector

The transient thermal behaviour of wickless heat pipe flat plate solar collectors has been analyzed with regard to various parameters. These parameters include global solar radiation intensity, inlet cooling water temperature, absorber plate material and thickness, ratio of pitch distance to wickless heat pipe diameter and ratio of condenser section length to total wickless heat pipe length. The results show that the selection of an absorber plate having a high value of conduction heat transfer rate per unit temperature difference is limited by the pitch distance.     

Experimental comparison of open sun drying and solar drying based on evacuated tube collector

In this article, an experimental comparison between open sun and solar drying is done. The thermal performance of evacuated tube based solar dryer is investigated with drying characteristics of Phyllanthus Emblica (Anvla), Aloe Vera, Aegle Marmelos (Bel) and leaves of Azadirachta Indica (Neem), Aegle Marmelos (Bel) and Psidium Guajava (Guava). In this setup, an evacuated tube collector, shell and tube heat exchanger and drying chamber are used. It was found that the maximum temperature difference between hot air and ambient air is 35.4°C and maximum efficiency of the setup is calculated as 55%. The average drying rate of Phyllanthus Emblica (Anvla), Aloe Vera and Aegle Marmelos (Bel) is measured as 0.46?g/min, 0.44?g/min, and 0.39?g/min respectively which are higher than that of Open Sun Drying. The leaves of Azadirachta Indica (Neem), Aegle Marmelos (Bel) and Psidium Guajava (Guava) also get dried with faster rates of 0.18?g/min, 0.17?g/min, and 0.14?g/min respectively.     

新型平板热管式太阳能PV/T集热系统的性能研究

文章搭建了新型平板热管式太阳能PV/T集热系统实验台,测试了该集热系统的热电性能。此外,建立了该集热系统的数学模型,并将该集热系统的测量结果和模拟结果进行对比分析,以验证该数学模型的准确性。最后,在相近的测试条件下,对新型平板热管式太阳能PV/T集热系统和传统圆形热管式太阳能PV/T集热系统的热电性能进行对比分析。分析结果表明,在相近的测试条件下,与传统圆形热管式太阳能PV/T集热系统相比,新型平板热管式太阳能PV/T集热系统的日平均热效率和日平均电效率分别提升了16.8%和3.5%,总集热量和总发电量分别提升了78.4%和35.5%。     

Integrated solar collector storage system based on a salt-hydrate phase-change material

A new integrated collector storage (ICS) concept for low-temperature solar heating of water is described. The solar energy is stored in a salt-hydrate phase-change material (PCM) held in the collector and is discharged to cold water flowing through a surface heat exchanger located in a layer of stationary heat transfer liquid (SHTL), floating over an immiscible layer of PCM. A theoretical model for the charging process of the proposed integrated collector is presented. The model assumes one-dimensional transient heat conduction in the PCM and SHTL layers and neglects the effect of convection heat transfer in these regions. The model was solved numerically by an enthalpy-based finite differences method and validated against experimental data. The results of parametric studies on the effect of the transition temperature and of the thickness layer of the salt-hydrate PCM on the thermal performance of the charging process are also presented.     

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     

Experimental studies on solar flat plate collector with internally grooved tubes using aqueous ethylene glycol

In order to cope up with the increase in energy demand and decline in fossil fuels, it has become imperative to use renewable resources efficiently. Among these renewable resources, solar thermal energy is abundant in nature. Solar water heating systems are one of the most important applications of solar thermal energy. Providing internal fins to absorber tube is the technique to improve heat transfer augmentation. Hence in the present study, experiments were performed on solar flat plate collector with different cross section of absorber tubes (plain tube and internally grooved tubes with different helix angles) and by varying the mass flow rates of the working fluids. This study reports the experimental results of flat plate collector, where the working fluid is water and aqueous ethylene glycol (50 : 50). Temperature profile of grooved absorber tube will be compared with plain tube. Since conversion efficiency of solar devices is low, the present study mainly focuses on improving the efficiency of solar flat plate collector.