Optimisation of Electrical Distribution System by Using Solar Thermal Powered Systems and Its Impact on Electrical Distribution Feeders

In this research, the performance of the solar thermal powered systems (STPS) is analyzed with different models (without inserts, with inserts and with Nano fluids with different concentrations) and its impact on the Electric load in a residential/Institutional Electrical Distribution system. For this purpose, the electrical and solar thermal water heater is tested and validated. Solar thermal powered systems and its impact on the Institutional electrical distribution feeders are tested and compared with the energy efficiency (EE) and cost optimization. The goal of this paper is to analyze the impact of solar thermal energy on electrical energy consumption in the electrical distribution feeder level. The electrical system cost and energy consumptions are tabulated and observed that there is a considerable savings.

In-Situ Preparation and Thermal Shock Resistance of Mullite-Cordierite Heat Tube Material for Solar Thermal Power

In order to improve the thermal shock resistance of solar thermal heat transfer tube material, the mullite-cordierite composite ceramic as solar thermal heat transfer tube material were fabricated by pressureless sintering using a-Al203, Suzhou kaolin, talc, and feldspar as starting materials. The important parameter for solar thermal transfer tube such as water absorption （W）, bulk density （Db）, and the mechanical properties were investigated. The phase composition and microstructure of the composite ceramics were analyzed by XRD and SEM. The experimental results show that the B3 sintered at 1 300 ℃ and holding for 3 h has an optimum thermal shock resistance. The bending strength loss rate of B3 is only 2% at 1 100℃ by air quenching-strength test and the sample can endure 30 times thermal shock cycling, and the water absorption, the bulk density and the bending strength are 0.32%, 2.58 g·cm-3, and 125.59 MPa respectively. The XRD analysis indicated that the phase compositions of the sample were mullite, cordierite, corundum, and spinel. The SEM images illustrate that the cordierite is prismatic grain and the mullite is nano rod, showing a good thermal shock resistance for composite ceramics as potential solar thermal power material.

Effect of Nano-ZrO_2 on Microstructure and Thermal Shock Behaviour of Al_2O_3/SiC Composite Ceramics Used in Solar Thermal Power

The Al2O3-ZrO2（3Y）-SiC composite ceramics used in solar thermal power were prepared by micrometric Al2O3,nano-ZrO2 and SiC powders under the condition of pressureless sintering.The bulk density and bending strength of samples with 10vol% nano-ZrO2 sintered at 1480℃ were 3.222 g/cm3 and 160.4MPa,respectively.The bending strength of samples after 7 times thermal shock tests （quenching from 1000℃ to 25℃ in air medium） is 132.0MPa,loss rate of bending strength is only 17%.The effect of nano-ZrO2 content on the microstructure and performance of Al2O3-ZrO2（3Y）-SiC composite ceramic was investigated.The experimental results show that the bending strength of samples with above 10vol% nano-ZrO2 content has decreased,because the volume expansion resulting from t-ZrO2 to m-ZrO2 phase transformation is excessive;Adding proper nano-ZrO2 would be contributed to improve the thermal shock resistance of the composite ceramics.The Al2O3-ZrO2（3Y）-SiC composite ceramic has promising potential application in solar thermal power.

Preparation and Characterization of Andalusite Ceramic Used for Solar Thermal Power Generation

High-temperature thermal storage material is one of the critical materials of solar thermal power generation system. Andalusite, kaolin, talc, γ-Al2O3 and partially stabilized zireonia were used as the raw materials, and in-situ synthesis of cordierite was adopted to fabricate thermal storage material for solar thermal power generation via pressureless sintering. The phase compositions, microstructures and thermal shock resistances of the sintered samples were analyzed by XRD, SEM and EDS, and the corresponding mechanical properties were measured. The results show that the major phases of the samples are mullite and zirconium silicate, and the pores distribute uniformly. After being sintered at 1 460℃C, A4 sample exhibits a better mechanical performance and thermal shock resistance, its loss rate of bending strength after 30 cycles thermal shock is 3.04%, the bulk density and bending strength are 2.86 g.cm^-3 and 139.66 MPa, respectively. The better thermal shock resistance of the sample is closely related to the effect of zirconium silicate, such as its uniform distribution, nested growth with mullite, low thermal expansion coefficient, high thermal conductivity, etc. This ceramic can be widely used as one of potential thermal storage materials of solar thermal power generation system.

Full scale experimental study of a small natural draft dry cooling tower for concentrating solar thermal power plant

Concentrating solar thermal power system can provide low carbon,renewable energy resources in countries or regions with strong solar irradiation.For this kind of power plant which is likely to be located in the arid area,natural draft dry cooling tower is a promising choice.To develop the experimental studies on small cooling tower,a 20 m high natural draft dry cooling tower with fully instrumented measurement system was established by the Queensland Geothermal Energy Centre of Excellence.The performance of this cooling tower was measured with the constant heat input of 600 kW and 840 kW and with ambient temperature ranging from 20 ℃ to 32 ℃.The cooling tower numerical model was refined and validated with the experimental data.The model of 1 MW concentrating solar thermal supercritical CO2 power cycle was developed and integrated with the cooling tower model.The influences of changing ambient temperature and the performance of the cooling tower on efficiency of the power system were simulated.The differences of the mechanism of the ambient temperature effect on Rankine cycle and supercritical CO2 Brayton cycle were analysed and discussed.

Modelling of Solar Thermal Power Plant Using Parabolic Trough Collector

The target of the National Solar Mission is to build up India as a worldwide pioneer in solar energy generation. Solar power can be transmitted through grid either from solar photovoltaic or solar thermal technology. As compared to solar photovoltaic, solar thermal installations are less studied, especially regarding energy estimation and performance analysis. For estimating the potential of CSP plants, it is planned to simulate a power plant. We have marginally modified the design of 1 MW operational power plant installed at Gurgaon using Parabolic Trough Collector (PTC) technology. The results are compared with the expected output of Gurgaon power plant and also 50 MW power plant at Rajasthan. Our results have closely matched with a small deviation of 3.1% and 3.6% for Gurgaon and Rajasthan plants, respectively. Our developed model is also validated with 18 different solar power plants in different parts of the world by slightly modifying the parameters according to the plant capacity without changing major changes to the plant design. Difference between our results and the expected energy generation varied from 0.4% to 13.7% with an average deviation of 6.8%. As our results show less than 10% deviation as compared to the actual generation, an attempt has been made here to estimate the potential for the entire nation. For this modelling has been carried out for every grid station of 0.25° × 0.25° interval in India. Our results show that annual solar thermal power plant of 1 MWe capacity potential varies from 900 to 2700 MWh. We have also compared our results with previous studies and discussed.

Operation Strategy Analysis and Configuration Optimization of Solar CCHP System

This paper proposed a new type of combined cooling heating and power(CCHP)system,including the parabolic trough solar thermal(PTST)power generation and gas turbine power generation.The thermal energy storage subsystem in the PTST unit provides both thermal energy and electrical energy.Based on the life cycle method,the configuration optimization under eight operation strategies is studied with the economy,energy,and environment indicators.The eight operation strategies include FEL,FEL-EC,FEL-TES,FEL-TES&EC,FTL,FTL-EC,FTL-TES,and FTL-TES&EC.The feasibility of each strategy is verified by taking a residential building cluster as an example.The indicators under the optimal configuration of each strategy are compared with that of the separate production(SP)system.The results showed that the PTST-CCHP system improves the environment and energy performance by changing the ratio of thermal energy and electric energy.The environment and energy indicators of FEL-TES&EC are superior to those of FTL-TES&EC in summer,and the results are just the opposite in winter.The initial annual investment of the PTST-CCHP system is higher than that of the SP system,but its economic performance is better than that of the SP system with the increase of life-cycle.

Potential Map for the Installation of Concentrated Solar Power in Northeast of Brazil Using Analytic Hierarchy Process (AHP)

Brazil has a predominantly renewable energy matrix, with large participation of water resource in domestic supply of energy. Data from 2019 National Energy Balance show that renewable sources (water, biomass, wind and solar photovoltaic) together represented 83% of domestic electric supply in 2018, where the remaining percentage (16.7%) represented non-renewable sources. The generation of electricity through thermal solar technology was not representative. However, it is known that Brazil presents high potential for the installation of solar thermal plants, especially in the Northeastern Region, where direct normal solar irradiation values are high. It is observed that the (high) costs of the projects associated to the absence of a specific incentive program make Concentrating Solar Power (CSP) plants installation more and more time consuming. As a way to contribute to the insertion of solar thermal energy in Brazil, this article presents a methodology for the location of parabolic trough solar thermal plants of 80 MW for the State of Bahia, located in the Northeastern Region of Brazil. Such methodology was based on the application the Analytic Hierarchy Process (AHP) method and the Geoprocessing Technologies to define potentially available sites for the implementation of the projects. For the analysis, parameters related to energy production in the solar power plant, electric, roadways and water infrastructure of the plant were taken into account, as well as the occupation, slopes and land use. Considering the analyses performed, it was confirmed that Bahia disposes of many sites with great generation potential, especially in the western region of the State (at Barreiras), where favorable conditions were found for the development of the technology. Localities situated in other region of the State were also confirmed as suitable, however with less site availability for the insertion of plants. Methodology validations were also carried out and indicated that the model reached the proposed objective, faithfully representing the real-world simplifications that were made.

Thermo-Economic Optimization of Solar Thermal Devices by Coherent Integration of Technologies

Radiation is a form of energy where the angular variable of the direction of its photons has a primary importance, particularly for radiation concentration processes, which are essential tools to reach high temperatures from radiation beams (as the solar ones) with moderate intensities. Solar radiation cannot be used directly to feed thermodynamic cycles, and optical concentration must be applied to that goal. In general, reflection from mirrors is preferred to refraction by lenses in this case, because they have less optical aberrations. Concentration conveys very high temperatures in the receiver. However, the higher the temperature, the lower the efficiency of the solar thermal apparatus. Besides that, economy also suffers quite a lot when going to very high concentration factors, which is one of the main burdens in the development of Solar Thermal Energy. A new configuration of solar radiation concentrator is presented. It includes a salient innovation in the way the mirrors are given the right curvature by mechanical forces. Those mirrors are originally flat and do not need any special thermal treatment for this purpose. The whole device concept has been guided by the principle of thermoeconomic coherence, which requires similar efforts in all degrees of freedom that have strong influence in the performance and cost of the system. The paper shows the decision tree that has oriented the project, following the principle of equilibrium in efforts, which leads to a design window of moderate values in the main variables. The prototype of this new configuration has already been built, and the first stage of research is considered to be finished, because the prototype has shown excellent conditions to include selected (fitting) technologies at a very low cost.

太阳能光热发电系统研究现状

针对太阳能光热发电系统,综述了光热发电系统中集热器、蓄热技术以及动力循环的研究及应用现状,并阐述了太阳能混合系统的优势,总结了太阳能光热发电系统面临的关键问题,为光热发电系统的发展提供参考。

新型光煤互补发电系统热力性能及技术经济性研究

为了减弱太阳能波动对光煤互补发电系统性能的影响,提出了新型光煤互补发电系统,建立了关键设备模型及子系统模型并进行验证,对新型光煤互补发电系统的热力性能及技术经济性进行了研究。结果表明:系统热力性能随运行负荷的下降而下降,随太阳辐照强度增加而先升高后下降;系统年均输出功率为699 MW,年均节煤率为7.506 g/(kW·h),年均光电效率为10.82%;储热时长为10 h时系统技术经济性最优,此时全寿命周期内净现值为4.18×10^(4)万元,内部收益率为11.81%,动态投资回收期为12.6 a,平均度电成本为0.402元/(kW·h),盈利能力较强。

抛物面槽式太阳能集热器球形接头测试系统的研制与应用

球形接头是抛物面槽式太阳能集热器的关键部件,针对球形接头易发生运转卡涩和导热油泄漏问题,研制了一套球形接头性能测试系统。该测试系统可以实现球形接头在旋转、摆转或旋摆联动模式下,以及在导热油温度达393℃和压力达4.1 MPa工况条件下的加速寿命测试。以导热油为传热流体,开展了球形接头在导热油温度为393℃和压力为2.3 MPa工况条件,以及温度、压力变化条件下的性能测试研究,分析了球形接头在模拟12年寿命期的扭矩特性和密封性能,验证了该测试系统运行的稳定性和可靠性,并且关键技术参数的控制精度和测量精度满足使用要求,为球形接头的性能评价提供了技术支撑。

Dynamic simulation and parametric influence analysis on thermal performance of a quartz tube solid particle receiver in solar tower power plants

Due to a higher operating temperature(≥800 ℃),Solar Particle Receiver(SPR)which uses particles as the working medium is considered as one of best candidates to improve the thermoelectric conversion efficiency of concentrating solar power plants.In this paper,a quartz tube solid particle receiver model is fully developed by using the discretized lumped parameter method,in which the calculation process of particle temperature and thermal loss is clearly given.In order to improve the manipulation level of particle receiver during the operation,the dynamic characteristics of the quartz tube particle receiver are comprehensively studied by the disturbance test of selected input parameters.Besides,in order to grasp the influence rule of key parameters on the thermal performance of particle receiver,the key parameters'sensitivity analysis is also deeply studied.The results show that the particle outlet temperature can reach as high as 810 ℃ under a relatively small value of solar flux 600 kW/m^(2),but the receiver efficiency is only about 75%;Besides,the receiver efficiency shows a variation tendency that it rises first falls afterwards with the increase of incident solar flux.The validity of proposed model is verified by a heating experi-mental system with a single quartz tube,and the relative error is not more than 7.9%.The research results are beneficial for understanding the dynamic characteristics and designing the particle receiver.

基于EES的太阳能光热发电系统性能模拟与优化

随着全球能源结构的持续转型和对可持续能源技术的不断追求,太阳能光热发电作为一种高效利用太阳能的方式受到了广泛关注。基于工程方程求解软件(Engineering Equation Solver,EES),构建高契合度的太阳能光热发电系统数学模型,对系统中的热力过程、能量转换效率以及关键影响因素进行模拟分析,进而提出一系列具有针对性的优化措施。实践证明,基于EES的太阳能光热发电系统的性能模拟与优化有助于提高系统光热发电效率,提升系统的经济性和环境友好性,降低能源损耗,具有广阔的应用前景。

采用热电半导体的小型海上太阳能集热发电系统

海洋中蕴含着多种形式的能源,且储量巨大,为了充分利用这些能源,提出了一种基于热电半导体发电技术的小型海上太阳能发电系统。这种系统利用太阳能产生热量来加热传热工质,利用海洋的波浪能实现传热工质的循环,利用热电半导体实现温差发电,从而实现将海洋太阳能和波浪能同时利用。介绍了该系统的结构组成和工作原理,通过对热电半导体的理论分析和仿真验证,发现热电半导体理论上可以实现10%的能量转化效率。由于该系统结构简单、无机械零部件、集成度高,因此具有可靠性高,维护成本低等优点,有一定的应用前景。

Fabrication and Thermal Properties of a New Heat Storage Concrete Material

A new type heat storage concrete material used in solar thermal power was fabricated by using aluminates cement to be the gelatinizer, and using high heat capacity materials, such as basalt and bauxite, as aggregate, and adding high heat conductivity graphite and high efficient water reducing agent. The experimental results show the addition of graphite can improve the thermal conductivity of the concrete, the value of thermal conductivity is about 2.34 W/mK which means the obtained concrete storage material has excellent thermal properties, and it is expected to be a good heat storage material used in solar power.

Performance Analysis of Multi-Energy Hybrid System Based on Molten Salt Energy Storage

This paper briefly summarizes the current status of typical solar thermal power plant system,including system composition,thermal energy storage medium and performance.The thermo-physical properties of the storage medium are some of the most important factors that affect overall efficiency of the system,because some renewable energy sources such as solar and wind are unpredictable.A thermal storage system is therefore necessary to store energy for continuous usage.Based on the form of storage or the mode of system connection,heat exchangers of a thermal storage system can produce different temperature ranges of heat transfer fluid to realize energy cascade utilization.Founded upon the review,a small hybrid energy system with a molten-salt energy storage system is proposed to solve the problems of heating,cooling,and electricity consumption of a 1000 m2 training hall at school.The system uses molten-salt storage tank,water tank and steam generator to change the temperature of heat transfer fluid,in order to realize thermal energy cascade utilization.Compared to the existing heating and cooling system,the proposed system needs more renewable energy and less municipal energy to achieve the same results according to simulation analysis.Furthermore,by improving the original heating and cooling system,PMV has been improved.The comprehensive efficiency of solar energy utilization has been increased to 83%.

基于混合神经网络的槽式太阳能集热场出口温度预测研究

为解决槽式太阳能集热场实际现场工况难以满足现有热性能测试标准的难题,提出一种基于混合神经网络(ALSTM)模型预测槽式太阳能集热场出口温度的方法。首先对中国科学院电工研究所延庆、常州龙腾乌拉特中旗、中广核德令哈、中船乌拉特中旗4处槽式太阳能集热场动态热性能实验数据和气象数据进行预处理与相关性分析,形成训练样本数据和验证样本数据;其次对该网络模型进行训练与优化,最后进行验证,得出上述4处集热场实际出口温度与预测出口温度的最大相对误差分别为3.00%、0.31%、1.45%、1.95%。证明了该模型的预测精度较高,为槽式太阳能集热场实际现场热性能预测与评价提供了一种新的方法。

考虑火电深度调峰的风光火储系统日前优化调度

深入挖掘火电机组深度调峰能力、实现风光火储多能互补运行是应对规模化新能源并网消纳的重要手段。提出火电机组深度调峰和爬坡成本、污染物惩罚成本、储能系统运行成本及新能源弃电惩罚成本的计算方法,建立了考虑火电深度调峰的风光火储系统日前优化调度模型。分别以风光出力最大、净负荷波动最小和系统运行成本最低为优化目标,并设定火电机组的不同调峰深度,对含高比例新能源的风光火储系统在典型日的优化调度策略进行仿真计算。结果表明:所建立的模型能够满足不同优化目标下的风光火储优化调度策略计算;通过提升火电机组深度调峰能力,可有效降低新能源弃电率。

太阳能光热发电标准体系研究

针对当前我国光热发电适用技术标准较少、标准体系建设滞后的问题,对太阳能光热发电技术标准研究现状进行了系统梳理。结合新型电力系统清洁低碳、安全高效、智慧灵活等需求,提出面向新型电力系统的光热发电技术标准体系总体架构,并提出涵盖14个领域(基础通用、安全通用、低碳环保通用、规划设计、工程建设、设备材料、调度控制、运行检修、试验与计量、市场营销等)、若干类目与具体标准构成的体系结构。进而,针对各领域标准化现状进行分析,明确当前7个领域存在空白、5个领域不甚完善的现状,提出分阶段重点布局的4点建议。