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1、兰州理工大学硕士学位论文碟式太阳能吸热器的性能实验研究姓名：李珍申请学位级别：硕士专业：热能工程指导教师：李金平20120608硕十学位论文摘 要太阳能是一种能量巨大、遍布世界且无污染的可再生能源，所以在环境污染日益严重和常规能源日益短缺的今天，太阳能受到了各国的普遍重视。太阳能热发电是一种高效大规模利用太阳能的方式，目前主要有槽式、塔式和碟式三种。与槽式和塔式太阳能热发电相比，碟式太阳能热发电系统启动损失小，光电效率高达294，在三种发电系统中位居首位，因而碟式太阳能热发电系统成为了人们关注的焦点。作为碟式聚光太阳热发电系统的核心部件之一，太阳能吸热器的作用是将聚光器反射聚集的太阳能最大限度
2、的吸收并传递给热媒，其吸热性能直接影响光热转换效率进而影响到整个热发电系统的可靠性和经济性，因此研究吸热器有非常重要的意义。本课题首先提出了一种新型腔式吸热器，继而研制了包含新型腔式吸热器在内的碟式太阳能集热系统，初步研究了碟式太阳能热发电系统集热性能并分析了腔式吸热器的吸热性能。本课题的主要研究内容和结果如下：1鉴于腔式吸热器的热损失在碟式太阳能热发电系统总损失中占有很大的比例，综合考虑与吸热器热损失相关的因素、吸热器的形状以及内部传热元件对腔式吸热器热性能的影响，本课题研制了一个整体半球状腔式吸热器，腔体外面包有保温材料。吸热器采光口面积与内表面积的比为1：8，采用八根1 80mm长、外径
3、14mm、壁厚2mm的重力式热管作为吸热器的传热元件，它们均匀在半径为85mm的圆周上，安装倾角为150，吸热器腔体内的热管部分长90mm，蒸发吸收聚集的太阳辐射能，保温层内是长40mm的绝热段。在热管内部充有无机换热工质。在热管蒸发段涂有Pyromark2500选择性吸收涂层。2在兰州市皋兰县建成了包含新型腔式吸热器在内的碟式太阳能集热系统，初步研究了腔式吸热器的性能。201 1年11月29日、201 1年12月1日、201 1年12月5日以及2011年12月22日(冬至)的实验结果表明：吸热器的腔体中心温度、采光口中心温度、吸热功率以及光热转换效率都与太阳直接辐射强度的变化趋势保持一致，首
4、先随时间逐渐上升，达到最大值后开始下降，而且腔体中心温度和采光口中心温度的最大值总是出现在太阳直接辐射强度最大值出现的附近。分析发现，光热转换效率的最大值通常出现在吸热功率最大值的附近。在太阳直接辐射量为5055Wm2时，吸热器的吸热功率为1686W，热效率为806，即表明本腔式吸热器具有良好的吸热性能，实验所涉及的太阳直接辐射强度是影响碟式太阳能集热吸热系统中吸热器的吸热功率和热效率的重要因素，文中最后分析了本实验系统出现的问题并提出了相应的解决办法。碟式太阿能吸热器的性能实验研究本课题的创新点是研制了新型腔式吸热器并初步揭示了新型腔式吸热器的吸热性能。碟式太阳能热发电系统是一种结构简单、布
5、局灵活、发电效率高、系统优化潜力和成本降低潜力大、初始投资少、应用前景广的太阳能热发电系统，国内外关于该系统的研究很少。本课题设计了一个新型腔式吸热器，并在兰州的天气条件下进行了初步性能实验，研究成果对碟式太阳能发电技术的试验示范和推广应用有重要的参考价值。本课题的研究得到了国家自然科学基金项目(51166008E0607)、国家科技部星火计划重点项目(2010GA860004)、国家科技支撑计划课题(2011BADl5803)、甘肃省教育厅项目(080306)、“陇原青年创新人才扶持计划项目(090165)、甘肃省建设科技攻关项目(JK201029)、甘肃省科技支撑计划(101lGKCA03
6、0)、甘肃省高等学校基本科研业务费(090258)和兰州理工大学“红柳杰出人才计划(Q201101)的共同资助。关键词：碟式太阳能热发电系统；腔式吸热器；实验研究；吸热功率；光热转换效率II硕十学位论文AbstractAs a kind of renewable energy，solar energy is tremendous and pollutionfree，itdistributes all over the world，SO in environmental pollution increasingly serious andconventional energy increasin
7、gly short today，solar energy has been got universalattention by all countriesSolar thermal power generation is an efficient largescale use of solar energy style，there are mainly trough，tower and disc three kindsCompared with trough and towersolar thermal power generation，disc solar thermal power gen
8、eration system starts withsmall loss and photoelectric efficiency as high as 294，ranks first in three systemsSO it becomes the focus of studyAs one of the core components in dish concentratingsolar thermal power generation system，solar heat receiver absorbs solar energy asmuch as possible which refl
9、ected by parabolic dish concentrator and its heatabsorbingproperties directly affect the light and heat conversion efficiency，thereby influence theoverall thermal power system reliability and economy，SO study the cavity receiver hasa very important significanceThis project proposed a new type cavity
10、 receiver firstly，and then developed adish solar collector system included the receiver，preliminary studied collectorperformance of the system and analyzed the heatabsorbing property of cavity absorberThe main research contents and results of this topic can be listed as follows：1In view of heat loss
11、 of cavity receiver has a large proportion in dish thermalpower generation system，comprehensively considered the factors related to heat 10SS。receiver shape and internal heat transfer component to cavity receiver thermalperformance，this topic developed an overall hemispheric shape cavity absorber，th
12、erewas insulation material outside the receiverThe area ratio between day lighting mouthand inside surface was 1：8，chose 8 gravity heat pipes as heat transfer elements，pipesis 1 80ram length，tube diameter is 1 4mm and wall thickness is 2ram，pipes wereuniform arranged in a circle which radius is 85mm
13、，inclination were 1 0，sections inheat receiver is 90mm which absorbed solar radiation in receiver，the adiabatic sectionis 40ram in the part of insulation layerWithin the heat pipes was inorganic heattransfer working fluidPyromark2500 selective absorption coating was coloured onpipes evaporator2Estab
14、lished a dish type solar collector system contained the new cavity heatreceiver in Gaolan county，Lanzhou city and preliminary studied the heatabsorbingIllperformance of the receiverThe experimental results of November 29，20 1 1，December 1，201 1，December 5，201 1 and December 22，201 1(winter solstice)
15、showedthat the temperatures at the center of the cavity and the lighting port center，theheatabsorbing power，and solar thermal conversion efficiency were completelyconsistent with the trend of direct solar radiation intensityFirst gradually increasedwith time then declined after reached the maximum a
16、nd the maximums of cavity centertemperature and lighting port center temperature were always around the direct solarradiation intensity maximumThrough calculation we found that the maximum ofheat2Lbsorbing power was always around the peak of solar thermal conversionefficiencv0n 20 1 1 Winter solstice，when direct solar radiation was 5055Wmz，theheat power was 1 686W；the thermal efficiency was 806The results showed that thenew cavit
