共查询到20条相似文献,搜索用时 46 毫秒
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上海锅炉厂有限公司自主开发了塔式太阳能热发电吸热器性能设计程序。该程序可同时适应水工质和熔盐工质太阳能吸热器的设计计算要求。针对美国Solar Two工程吸热器,将Boeing North American,Inc.的计算结果和其试验数据与自主开发程序的计算结果进行比较,结果吻合良好。以某个塔式太阳能热发电吸热器为例,对其蒸发段和过热段的设计方案进行了详细的校核计算,重点在吸热器蒸发段的循环流量、干度、鳍端温度和鳍端温差、过热段的管子正面点温度以及吸热器的吸热效率分布等多个方面进行了分析。该校核计算的结果可为后续进行性能评价提供重要的基础数据。 相似文献
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针对太阳能碟式聚光器,设计了一种工质为超临界二氧化碳的圆台形腔式吸热器,建立了腔式吸热器的光热模型。采用蒙特卡洛光线追踪法分析了腔式吸热器的光学特性,并基于相关理论,将热边界条件导入Ansys Fluent软件中,对腔式吸热器的光学特性及流动传热特性进行了计算流体力学(CFD)仿真模拟,得到腔式吸热器内工质出口温度、工质流动压降、光学效率、热效率以及散热损失随着工质进口温度(100~200℃)和太阳光辐射强度(400~1 200 W/m2)的变化规律。结果表明:不同太阳光辐射强度下,吸热器的光学效率基本不变;太阳光辐射强度对腔式吸热器热效率的影响不明显;工质进口温度越高,吸热器的热效率越低;腔式吸热器散热损失中,自然对流散热损失最大,其次是辐射散热损失及导热散热损失。 相似文献
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Heat transfer enhancement and performance of the molten salt receiver of a solar power tower 总被引:1,自引:0,他引:1
This paper investigates the interaction between the heat transfer performance and the thermal efficiency of a molten salt receiver used in the solar power tower plant. A test-bed is built, and a series of experiments of heat transfer enhancement for two types of molten salt receiver tubes, including smooth and spiral tubes, have been carried out under the high temperature and the high heat flux conditions. The experimental results show that the Nusselt numbers of spiral tube with heat transfer enhancement are in the range of 400–1200, which is about 3 times than that of the smooth one on average. The wall temperature of the spiral tube is decreased by about 30 °C comparing with that of the smooth tube under the identical heat transfer conditions. The results of the experiment show that, by using the spiral tube as the heat transfer tube, the heat transfer performance of the molten salt receiver is obviously improved, and the radiation and convection losses are significantly reduced. The results will be helpful for the design of the molten salt receiver. 相似文献
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Based on enthalpy method, numerical studies were performed for high temperature molten salt phase change thermal energy storage (PCTES) unit used in a dish solar thermal power generation system. Firstly, the effects of the heat transfer fluid (HTF) inlet temperature and velocity on the PCTES performance were examined. The results show that although increasing the HTF inlet velocity or temperature can enhance the melting rate of the phase change material (PCM) and improve the performance of the PCTES unit, the two parameters will restrict each other for the fixed solar collector heat output. Then three enhanced tubes were adopted to improve the PCTES performance, which are dimpled tube, cone-finned tube and helically-finned tube respectively. The effects of the enhanced tubes on the PCM melting rate, solid–liquid interface, TES capacity, TES efficiency and HTF outlet temperature were discussed. The results show that compared with the smooth tube, all of the three enhanced tubes could improve the PCM melting rate. At the same working conditions, the melting time is 437.92 min for the smooth tube, 350.75 min for dimpled tube which is reduced about 19.9% and 320.25 min for cone-finned tube which is reduced about 26.9% and 302.75 min for helically-finned tube reduced about 30.7%. As a conclusion, the thermal performance of PCTES unit can be effectively enhanced by using enhanced tube instead of smooth tube. Although, the HTF pressure drops for the enhanced tubes are also larger than that of the smooth tube, the largest pressure drop (1476.2 Pa) is still very lower compared with the working pressure (MPa magnitude) of the dish solar generation system. So, the pressure drops caused by the enhanced tubes could almost be neglected. 相似文献
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The design of a global steady-state thermal model of a 100 kWt molten salt cavity receiver was developed as part of the key project of the Ministry of Science and Technology of People's Republic of China (MOST). In the design process, the following factors were analyzed: receiver area, heat loss (convective, emissive, reflective and conductive), number of tubes in the receiver panel, tube diameter and receiver surface temperature. The model was also used to calculate the receiver performance of the Sandia National Laboratories' molten salt electric experiment (MSEE). In addition, the thermal performance of the designed molten salt cavity receiver is presented for a fixed outlet flow rate and a fixed output temperature. 相似文献
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以硫酸钠、硫酸钾和硫酸镁为原料,采用在硫酸钠-硫酸钾二元共晶盐中加入硫酸镁的方法制备三元硫酸熔盐。应用TG-DSC联用分析仪、热常数分析仪、X射线衍射仪以及热循环法对复合熔盐的熔点、相变潜热、热导率、比热容、分解点以及热稳定性进行表征。结果表明:所制备的三元硫酸熔盐熔点分布在667.5~669.7 ℃之间,较二元熔盐熔点降低了160 ℃左右,硫酸镁含量为30%(质量分数)的三元硫酸熔盐相变潜热值最大为94.3 J/g,比热容最大为1.13 J/(g·K)(720℃≤T≤800℃),导热系数为0.41 W/(m·K),分解温度为1070 ℃,经50次热循环后,相变潜热值降低约4.34%,熔点和物相保持基本恒定,具有良好的热稳定性。该研究为硫酸盐作为高温传热蓄热介质提供了依据。 相似文献
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In order to investigate the steady heat transfer characteristics of a porous media solar tower receiver developed in China, this paper applies the steady heat and mass transfer models of the porous media to solar receivers, chooses the preferable volume convection heat transfer coefficient model, solves these equations by using the numerical method, and analyzes the typical influences of the porosity, average particle diameter, air inlet velocity, and thickness on the temperature distribution. The following conclusions have been drawn: in the same position or relative position along the downstream, the bigger the average particle diameter is, the higher the solid matrix dimensionless temperature is, the higher the air dimensionless temperature is. The bigger the porosity is, the lower the solid matrix dimensionless temperature is, the bigger the porosity is, the higher the air dimensionless temperature is. The bigger the thickness is, the lower the solid matrix dimensionless temperature is, the higher the air dimensionless temperature is. In a certain depth, the bigger the air inlet velocity is, the higher the solid matrix dimensionless temperature is. After a certain depth, the bigger the air inlet velocity is, the lower the solid matrix dimensionless temperature is, and the bigger the air inlet velocity is, the higher the air dimensionless temperature is. The paper can provide a reference for this type of receiver design and reconstruction. 相似文献
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Test methods for estimating the thermal performance of the molten salt receiver are a matter of ongoing concern. To date, test methods in the literature require receiver to be operated in steady state or quasi-steady state. However, the receiver is always operating in the unsteady state with ongoing changes in power absorption and flow rate. Therefore, research into dynamic test method for the molten salt cavity receiver is required. The Transfer Function Method (TFM) is a successful dynamic test method for solar collectors. In this paper, a theoretical analysis of the TFM was applied to the molten salt cavity receiver and then verified by indoor transient experiments. The TFM predicted outlet temperature of the receiver was compared with experimental data. The results showed that the TFM accurately predicted the outlet temperature trends despite some errors between predicted and measured outlet temperature. The errors may have originated from the changing flow rate. The TFM is a good candidate as a dynamic test method for the concentrated solar receiver. 相似文献
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Exergetic analysis and economic evaluation of central tower receiver solar thermal power plant 下载免费PDF全文
This article presents the analytical evaluation of a central tower receiver solar thermal power plant with air‐cooled volumetric receiver using exergy analysis. The energetic and exergetic losses as well as the efficiencies of a typical central tower receiver‐based solar thermal power plant have been carried out under the specific operating conditions. The enhancement in efficiency of the plant from the variation in power input to constant power input achieved by thermal storage backup condition has been determined. It is found that the year round average energetic efficiency can be increased from 24.15% to 25.08% and year round average exergetic efficiency can be increased, from 26.10% to 27.10% for the selected location Jodhpur. The unit cost of electric energy generation (kWhe) is found to be INR 10.09 considering 30‐year lifespan of the solar plant along with a 10% interest rate. The present study provides a base for the development of future solar thermal power plants in India. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
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The dynamical and thermal performances of molten salt pipe during the filling process are numerically investigated using volume of fluid model. The whole filling process has three main stages, or the developing stage with the interface width quickly increasing, the fluctuating stage with the interface width fluctuating and the fully developed stage with stable interface, and then associated interface structures, flow and temperature fields are described in detail. Before the molten salt flows through a certain position, the fluid temperature will jump within a short time, while the wall temperature only linearly increases after that. The heat transport during the filling process is mainly dependent upon the pipe wall and molten salt flow, while natural convection outside can almost be ignored. The dimensionless interface temperature has similar evolution process under different surrounding temperatures, but it will apparently increase with the flow velocity rising. In addition, the pipe will be blocked when the interface temperature drops below the freezing point, so a model of penetration distance is derived by correlating the interface temperature evolution process, and it has a good agreement with available experimental results. 相似文献
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Analysis of thermal performance of electromagnetic induction based molten salt heating system 下载免费PDF全文
将电磁感应加热技术应用到低谷电加热熔盐储热供暖领域,搭建熔盐电磁感应加热实验系统,以感应加热器为研究对象,探究熔盐以及线圈冷却水在不同熔盐流速和线圈电流工况下的温度变化规律,计算加热效率和冷却水热损失率。结果表明:电磁感应加热器可以快速加热熔盐,熔盐温升主要集中在开始加热80~240 s之间,温升速率在100 s时最大;改变线圈电流或熔盐流速,可以产生不同终温的熔盐,流速0.177 m/s时,熔盐在不同电流下出口温度分别为201.452 ℃、203.891 ℃、207.599 ℃、212.975 ℃和221.454 ℃;熔盐流速一定,熔盐和线圈冷却水吸热量随线圈电流的增加而升高;线圈电流不变,熔盐吸热量随流速的增加而升高、线圈冷却水吸热量随流速增加而降低;熔盐流速0.296 m/s、线圈电流600 A时,熔盐加热效率为69.28%,线圈冷却水热损失率为16.45%。 相似文献