Performance analysis of a photovoltaic/thermal system with lunar regolith-based thermal storage for the lunar base

Powering a moon base,especially keeping it warm during the long lunar night,is a big challenge.This paper introduces a photovoltaic/thermal(PV/T)system incorporating regolith thermal storage to solve the challenge of power and heat provision for the lunar base simultaneously.The vacuum of space around the moon helps this system by reducing heat loss.During the moon's daytime,the system not only generates electricity but also captures heat.This stored heat in the regolith is then used at night,reducing the amount of equipment we need to send from Earth.The spectrally selective PV/T panels are designed to absorb a wide range of sunlight(0.3–2.5μm)while minimizing heat loss in the infrared range(3–30μm).Simulation results of the hybrid solar energy system indicate the average value of the overall efficiency is 45.9%,which relatively elevates 56.1%compared to the PV system.The launch mass of the proposed PV/T system is only 8.4%of a traditional photovoltaic-lithium battery system with the same amount of energy storage.And the total specific energy of the proposed system is 7.3 kWh kg^(-1),while that of the photovoltaic-lithium battery system is about 0.3 kWh kg^(-1).In summary,this study proposes an alternative combined heat and electricity supply system for the lunar base,which can greatly reduce the launch mass and free up load for other scientific research equipment.

A switchable concentrating photovoltaic/concentrating solar power(CPV/CSP)hybrid system for flexible electricity/thermal generation

Due to the intermittency and indeterminacy of solar irradiance,balancing energy supply and load demand remains a challenge.This paper proposed a switchable hybrid system that combines concentrating photovoltaic/concentrating solar power(CPV/CSP)technology with thermal energy storage(TES)to achieve flexible electricity and thermal generation by adjusting the incident solar flux of photovoltaic(PV).The hybrid system can directly transfer surplus solar energy into high-quality heat for storage using a rotatable PV/heat receiver.The simulated results demonstrated that the hybrid system effectively improves power generation,optimally utilizes TES capacity,and reduces the levelized cost of electricity(LCOE).Over a selected seven-day period,the single-junction(1J)Ga As solar cells used in the hybrid system sustainably satisfied the load demand for more than five days without grid supplement,outperforming the CSP plant by an additional two days.The hybrid system utilizing the 1J Ga As with the base configuration of solar multiple(SM)of 1.26 and TES capacity of 5 h improved the annual power production and renewable penetration(RP)by 20.8%and 24.8%compared with the conventional CSP plant,respectively.The hybrid plant with monosilicon and a configuration of SM(1.8),PV ratio(1),and TES capacity(6 h)achieved an optimal LCOE of11.52$ct/k Wh and RP of 75.5%,which is 8.8%lower and 12.1%higher than the CSP plant,respectively.

计及风光不确定性的风-光-光热联合发电系统中光热电站储热容量优化配置

传统新能源电站之间联合形式单一且未考虑风光出力不确定性,弃风、弃光现象严重。为此,提出了一种考虑风光不确定性的风-光-光热联合系统的光热电站储热容量优化配置策略,利用电转热技术使风光电站和光热电站有效耦合,明确联合系统框架与原理;采用改进拉丁超立方抽样方法抑制风光出力的不确定性。最后,构建基于风光出力典型场景的光热电站储热容量双层优化配置模型,并进行算例求解,结果表明所提方法显著降低了系统总投资与运行成本,提高了清洁能源消纳能力。

A review of concentrated photovoltaic-thermal(CPVT) hybrid solar systems with waste heat recovery(WHR)

In conventional photovoltaic(PV) systems, a large portion of solar energy is dissipated as waste heat since the generating efficiency is usually less than 30%. As the dissipated heat can be recovered for various applications, the wasted heat recovery concentrator PV/thermal(WHR CPVT) hybrid systems have been developed. They can provide both electricity and usable heat by combining thermal systems with concentrator PV(CPV) module, which dramatically improves the overall conversion efficiency of solar energy.This paper systematically and comprehensively reviews the research and development of WHR CPVT systems. WHR CPVT systems with innovative design configurations, different theoretical evaluation models and experimental test processes for several implementations are presented in an integrated manner. We aim to provide a global point of view on the research trends, market potential, technical obstacles, and the future work which is required in the development of WHR CPVT technology. Possibly, it will offer a generic guide to the investigators who are interested in the study of WHR CPVT systems.

Optical analysis of a hybrid solar concentrating Photovoltaic /Thermal (CPV/T) system with beam splitting technique

A novel hybrid solar concentrating Photovoltaic/Thermal (CPV/T) system with beam splitting technique is presented. In this system, a beam splitter is used to separate the concentrated solar radiation into two parts: one for the PV power generation and the other for thermal utility. The solar concentrator is a flat Fresnel-type concentrator with glass mirror reflectors. It can concentrate solar radiation onto solar cells with high uniformity, which is beneficial to improving the efficiency of solar cells. The thermal receiver is separated to the solar cells, and therefore, the thermal fluid can be heated to a relatively high temperature and does not affect the performance of solar cells. A dimensionless model was developed for the performance analysis of the concentrating system. The effects of the main parameters on the performance of the concentrator were analyzed. The beam splitter with coating materials Nb2O3 /SiO2 was designed by using the needle optimization technique, which can reflect about 71% of the undesired radiation for silicon cell(1.1m < 3m) to the thermal receiver for thermal utility. The performance of this CPV/T system was also theoretically analyzed.

Performance Evaluation and Optimization of a Novel System Combining a Photovoltaic/Thermal Subsystem&an Organic Rankine Cycle Driven by Solar Parabolic Trough Collector

A novel coupling system that combines a photovoltaic/thermal(PV/T)subsystem and an Organic Rankine Cycle(ORC)driven by solar parabolic trough collector(PTC)is presented in this paper.The mathematical model is initially built.On the basis,the influence of area ratio of two collectors(PV/T and PTC)on the performance of system is discussed.The results show that the optimal area ratio of PV/T to PTC is 8:2,which can achieve the maximum energy output.Moreover,the performance of the coupling system and two independent systems(PV/T and ORC system)are compared and analyzed.The results show that the coupling system is more reliable and its total output energy(heat and electricity)is the highest,compared with the other two independent systems.The solar energy utilization efficiency of the coupling system is 40%higher than that of the other two independent systems in the steady-state simulation.Moreover,the annual output energy per unit area collector of the coupling system is 13%higher than that of the other two independent systems in the dynamic simulation.Furthermore,in the dynamic simulation of a typical day,the PV panels’temperature of the coupling system is 5℃–7℃ lower than that of the independent PV/T system.It means that the power generation efficiency of PV panels can be increased by 1.5%–3.5%.This study aims to explore the operation characteristics of the novel solar energy utilization coupling system and promote the development of renewable energy utilization models,which provides a reference for the design and optimization of related energy systems.

基于CNT/Ag纳米流体的分光谱太阳能光伏光热系统实验研究

传统太阳能光伏光热(PV/T)系统的光电转换和光热转换过程耦合在一起,对太阳能全光谱能量的利用率较低,为使得光电、光热过程解耦,该文探究Ag、CNT、CNT/Ag纳米流体作为分光谱PV/T系统媒介时的光谱及能量性能。首先对不同浓度纳米流体的光谱性能进行测试,然后通过实验研究不同浓度的CNT/Ag纳米流体对系统电效率和热效率的影响。结果发现相比于Ag纳米流体,浓度为1×10^(6)、3×10^(6)、5×10^(6)、1×10^(7)μg/m^(3)的CNT/Ag纳米流体在太阳电池光谱响应区的透过率分别上升了8.6%、9.3%、8.5%、9.2%,响应区外波段的吸收率增加了30.4%、44.5%、58.4%、56.7%。系统电效率最高为8.2%、热效率最高为45%,当CNT/Ag纳米流体浓度为5×10^(6)μg/m^(3)时,分光谱容器效率最高为18.3%时热效率达到了43%,电效率为7%。

太阳能利用技术及其应用

结合太阳能利用技术及应用领域的最新进展,介绍了太阳能资源的优缺点及其在中国的分布状况,系统地综述了太阳能主要利用技术的研究进展和应用,详细论述了太阳能在国内外的开发利用情况,指出我国加快发展太阳能产业应采取的措施。

采用热管冷却技术的太阳能光伏电–热一体化系统性能分析

太阳能光伏电–热(photovoltaic-thermal,PV-T)一体化系统将光伏组件与太阳能热利用系统组合在一起,具有较高的太阳能综合利用效率。针对热管具有高效传热和均温性能的特点,提出一种采用热管冷却技术的太阳能光伏电-热一体化系统;基于光伏电池板传热过程特点及换热器的传热有效度——传热单元数(ε-NTU)法,对热管式PV-T系统的电池板温度、冷却流体出口温度以及系统电效率和热效率等热电转换性能进行了理论分析和计算。结果表明,热管式PV-T系统的电池温度变化幅度在2.5℃以内,系统电效率和热效率分别达到6.99%～7.46%和51.0%～63.2%。该文提出的理论方法为研究热管式PV-T系统热电转换性能提供了一种新的途径,可用来分析和讨论相关参数对热管式PV-T系统性能的影响。

有、无玻璃盖板工况对PV/T系统性能的影响

同时参考热力学第二定律和第一定律,以效率和能量效率作为判据,在一些结构参数和环境参数变化的条件下,对有、无玻璃盖板工况下 PV/T 系统的综合性能进行了对比分析,并尝试对玻璃盖板在 PV/T 系统中的应用给出一些建议。

太阳能电热联用系统研究进展

首先对太阳能电热联用系统的基本组成形式进行了简要介绍,并对不同的电热联用集热器、热能利用 方式进行了对比分析,接着对电热联用的研究方法和发展现状进行了详细说明,并列举了一些电热联用产品和 示范工程,最后指出了电热联用发展中应解决的问题,并对其发展前景进行了展望。

光伏-太阳能热泵在不同冷凝水温下的特性

提出了光伏-太阳能热泵(PV-SAHP)的系统原理,建立了PV-SAHP系统试验台.在不同的冷凝水温工况下,对PV-SAHP系统的动态性能进行了实验和分析,同时也就不同冷凝水温对PV-SAHP系统性能的影响进行了对比.PV-SAHP系统平均性能系数为5.4,最高COP可达10.4,平均光电效率为13.4%.结果表明PV-SAHP系统具有优越的热泵性能和光电转换效率.

对光伏热水墙体光电光热性能的数值模拟研究

采用数值模拟的方法动态地分析了光伏热水墙体的光电光热特性,并就系统中电池覆盖率、工作流体质量流率对系统热效率和电力输出的影响进行了研究,得到了系统优化设计的性能参数。

太阳能光伏/光热复合集热器能量转换性能的数值模拟

建立太阳能光伏/光热(PV/T)复合集热器的光电与光热耦合能量转换的数值模型,利用TRNSYS软件模拟PV/T集热器的光电、光热转换性能,分析结构参数和运行参数对PV/T集热器的能量转换性能的影响。计算结果表明:减小集热板排管的管间距与管径的比值有利于提高光热与光电转换性能;冷却流体的入口温度对PV/T集热器的性能影响显著,较低的入口流体温度有利于保持更高的光热和光电转换效率。增加冷却流体的入口质量通量可提高光热和光电效率;当入口质量通量增加至6.9 g/(s·m2)时,PV/T集热器的热、电效率分别为66.2%和10.8%,进一步增加入口质量通量对提高光热、光电效率的作用不大。

零能耗建筑中太阳能的应用

首先简单介绍零能耗建筑,指出该项技术的良好发展前景。其次,分析太阳能的应用价值和前景,指出当前太阳能利用的两种主要方式。结合国内外零能耗建筑的发展状况和实例,介绍零能耗建筑中太阳能利用的常见形式,围绕太阳能热利用和电利用两个重点,针对部分典型的零能耗建筑实例深入分析,总结其在太阳能热利用和电利用方面的具体措施。最后,指出在零能耗建筑中广泛使用太阳能的必要性,并总结零能耗建筑中关于太阳能利用的一些特性及注意事项。

太阳能光电–热一体化与热泵耦合系统的热力性能实验研究

太阳能光电?热一体化(solar photovoltaic-thermal hybrid,PV-T)系统产生的热水的温度通常达不到生活所需的水温,如果和热泵联合工作,则可以提供较高温度的热水,系统的实用性明显提高。理论上在PV-T提供的热能与热泵吸收的热能相等时,PV-T与热泵能很好的匹配耦合,在此基础上建立了PV-T与热泵耦合的热力分析模型。结合热管式PV-T系统实验装置和热泵实验装置进行测试的实验数据,对该耦合系统的热力性能进行分析,基于两种不同算法,得出了匹配情况下PV-T耦合热泵系统的COP,实验还得出PV-T系统的火用效率为0.08左右,热泵的火用效率为0.38左右,匹配情况下耦合系统的火用效率为0.05左右,该PV-T耦合热泵系统有较好的节能效果。文中对系统提出了节能建议。该研究结果为PV-T与热泵耦合工作的应用及其系统参数的选用提供理论依据。

新型PV/T太阳能利用复合系统的实验研究

为提高PV/T系统太阳能利用率,同时获得可利用的热水和电力,将铝合金背板型单晶硅光伏组件和自行设计制作的不锈钢扁盒式集热板相结合,用导热硅胶加以粘接制成新型光伏光热一体化(PV/T)复合系统,该系统实现了光伏组件与集热板之间良好的粘接性、绝缘性和热传导,并在昆明地区对系统进行测试,分析了系统在不同水箱水容量及不同天气工况下运行的光电光热性能。结果表明,系统在75kg水箱水容量(m)晴天工况下运行效率更高,系统的平均电效率、热效率、综合效率及综合性能效率分别在14%、37%、51%、70.72%左右,与系统在50kg水箱水容量晴天或75kg水箱水容量多云工况下运行相比,综合性能效率约提高了11.86%或2.09%。与独立的光热或光伏系统相比,具有占地面积小、太阳能利用率高、更经济等优势。

低品位能源发电系统研究进展

介绍了适用于低品位能源的有机朗肯循环余热发电、卡琳娜循环余热发电、温差发电、热声发电4种热发电形式的原理和特点,分析了有机朗肯循环工质对系统性能的影响和热声发电系统的转换效率,指出太阳能的综合利用具有良好的发展前景。提出了可有效利用太阳能的太阳能电池余热方案,即光伏光热联合发电的有机朗肯循环系统,该系统的两相升压装置将太阳能电池的余热转化为液轮机的电力输出,实现了将太阳能转化为电能的过程,提高了太阳能的综合利用率。

太阳能热混合发电系统综述

掌握太阳能热混合发电系统的联合发电模式、性能分析,对推进我国太阳能热混合发电系统的发展有十分重要的意义。对太阳能热混合发电系统各发电模式的工作原理、主要性能参数,以及系统的关键研究和发展趋势进行了全面的介绍,并针对我国的实际状况对各种模式进行分析,给出了太阳能热混合发电系统在我国的发展前景。结果表明:太阳能与朗肯循环联合发电系统的技术发展比较完善,现阶段具有很大的发展前景。太阳能煤气化联合发电能够实现CO2零污染,随着技术的发展会发挥重要的作用。