Advanced power cycles for concentrated solar power

Solar Energy ◽  
2017 ◽  
Vol 152 ◽  
pp. 91-105 ◽  
Author(s):  
W.H. Stein ◽  
R. Buck
Keyword(s):  
Solar Power ◽  
Concentrated Solar Power ◽  
Power Cycles

O PROCESSO DE LICENCIAMENTO AMBIENTAL DE USINAS HELIOTÉRMICAS (CONCENTRATED SOLAR POWER – CSP): CONSIDERAÇÕES SOBRE SUA SIMPLIFICAÇÃO

2017 ◽  
Vol 32 (3) ◽  
pp. 248
Author(s):  
Marcelo Lampkowski ◽  
Odivaldo José Seraphim ◽  
Anselmo José Spadotto
Keyword(s):  
Solar Radiation ◽  
Solar Power ◽  
Mechanical Energy ◽  
Thermal Power ◽  
Electric Energy ◽  
Concentrated Solar Power ◽  
Power Cycles ◽  
Adoption And Implementation ◽  
High Incidence ◽  
Environmental Licensing

Empreendimentos baseados em tecnologias de energia solar concentrada (Concentrated Solar Power - CSP), também chamada de solar-térmica ou heliotérmica, fazem uso de sistemas de concentração da radiação solar para obtenção de quantidades significativas de fluido a altas temperaturas para aplicação em ciclos térmicos de potência. Em usinas CSP, o calor do sol é captado e armazenado para, depois, ser transformado em energia mecânica e, por fim, em eletricidade. O calor recolhido aquece um líquido (fluido térmico) que passa por um receptor. Esse líquido armazena o calor e serve para aquecer a água dentro da usina e gerar vapor. A partir daí, o vapor gerado movimenta uma turbina e aciona um gerador, produzindo, assim, energia elétrica. No Brasil, apesar do alto índice de radiação solar direta incidente, ainda são escassos os projetos envolvendo a energia heliotérmica e acredita-se que alguns dos fatores que dificultam a adoção e a implementação destas tecnologias no país estão relacionados à complexidade do processo de licenciamento ambiental para construção e operação de usinas CSP e à ausência de uma legislação ambiental específica para empreendimentos baseados na heliotermia. Este artigo se propôs a apresentar os principais aspectos da legislação existente em relação à impactos ambientais e aos processos para a obtenção das licenças ambientais, relacionando-os com as características de usinas CSP. Com base na análise dos requisitos para os procedimentos de licenciamento levantados, foram desenvolvidas propostas para o estabelecimento de diretrizes de licenciamento que são essenciais para o desenvolvimento do mercado CSP no Brasil.PALAVRAS-CHAVE: Energias renováveis, energia solar concentrada, legislação vigente. THE CONCENTRATED SOLAR POWER (CSP) ENVIRONMENTAL LICENSING PROCESS: CONSIDERATIONS ABOUT ITS SIMPLIFICATIONABSTRACT: Plants based on Concentrated Solar Power (CSP) technologies, also called solar-thermal or heliothermal, make use of solar radiation concentration systems to obtain significant quantities of fluid at high temperatures for application in thermal power cycles. The sunlight is captured and stored. Then it is converted into mechanical energy and finally into electricity. The collected heat heats up a liquid (thermal fluid) that passes through a receiver. This liquid stores the heat and serves to heat the water inside the plant and generate steam. From there, the steam moves a turbine and drives a generator, thus producing electric energy. In Brazil, despite the high incidence of direct solar radiation, projects involving heliothermic energy are still scarce and it is believed that some of the factors that hinder the adoption and implementation of these technologies Brazil are related to the complexity of the environmental licensing process for construction and operation of CSP plants and also the absence of a specific environmental legislation for CSP projects. This paper proposes to present the main aspects of the existing legislation in relation to the environmental impacts and the processes to obtain the environmental licenses, relating them to the characteristics of CSP plants. Based on the analysis of the requirements for the licensing procedures raised, proposals were developed for the establishment of licensing guidelines that are essential for the development of the Brazilian CSP market.KEYWORDS: Renewable energies, concentrated solar power, current legislation

High-Temperature Heat Transport and Storage Using LBE Alloy for Concentrated Solar Power System

2015 ◽  
Author(s):  
Jin-Soo Kim ◽  
Adrian Dawson ◽  
Robert Wilson ◽  
Kishore Venkatesan ◽  
Wesley Stein
Keyword(s):  
High Temperature ◽  
Heat Transport ◽  
Solar Power ◽  
Liquid Metals ◽  
Test System ◽  
Concentrated Solar Power ◽  
Power Cycles ◽  
Operation Temperature ◽  
Air Turbine ◽  
Temperature Heat

Liquid metals have received growing attention as a potential replacement for more conventional heat transfer fluids in concentrated solar power (CSP) systems. Owing to liquid metals high thermal conductivity, an increase in solar receiver efficiency as well as higher serviceable temperatures could enable more advanced power cycles to be integrated to the CSP system. Recently, CSIRO carried out research on a solar air turbine system which includes a demonstration of a high-temperature pressurized air receiver combined with high-temperature thermal storage. Since the operation temperature of a solar air turbine system is much higher than that of conventional CSP systems, Lead-Bismuth Eutectic (LBE) alloy was chosen for its favorable high temperature heat transport properties and relative ease of storage. The heat test apparatus consisted of a LBE-air heat exchanger, storage tanks with internal heating elements and a pumping system developed by CSIRO. During the test, approximately 1,000 kg of LBE was successfully pumped while capturing and storing approximately 35MJ of solar energy. The test successfully transferred heat from the solar air receiver to the LBE, with the temperature of stored LBE reaching over 770 °C. This paper will present the concept of the test system, design of its components, procedures and results of the test, and also lessons learnt.

S-Ethane Brayton Power Conversion Systems for Concentrated Solar Power Plant

2015 ◽  
Vol 138 (1) ◽  
Author(s):  
Luis Coco Enríquez ◽  
Javier Muñoz-Antón ◽  
José María Martínez-Val Peñalosa
Keyword(s):  
Power Plants ◽  
Solar Power ◽  
Subcritical Water ◽  
Plant Performance ◽  
Solar Collectors ◽  
Steam Generation ◽  
Concentrated Solar Power ◽  
Power Cycles ◽  
Solar Power Plants ◽  
Recompression Cycle

The objective of this investigation is the comparison between supercritical ethane (s-ethane, C2H6) and supercritical carbon dioxide (s-CO2) Brayton power cycles for line-focusing concentrated solar power plants (CSP). In this study, CSP are analyzed with linear solar collectors (parabolic trough (PTC) or linear Fresnel (LF)), direct molten salt (MS), or direct steam generation (DSG) as heat transfer fluids (HTF), and four supercritical Brayton power cycles configurations: simple Brayton cycle (SB), recompression cycle (RC), partial cooling with recompression cycle (PCRC), and recompression with main compression intercooling cycle (RCMCI). All Brayton power cycles were assessed with two working fluids: s-CO2 and s-ethane. As a main result, we confirmed that s-ethane Brayton power cycles provide better net plant performance than s-CO2 cycles for turbine inlet temperatures (TITs) from 300 °C to 550 °C. As an example, the s-ethane RCMCI plant configuration net efficiency is ∼42.11% for TIT = 400 °C, and with s-CO2 the plant performance is ∼40%. The CSP Brayton power plants were also compared with another state-of-the-art CSP with DSG in linear solar collectors and a subcritical water Rankine power cycle with direct reheating (DRH), and a maximum plant performance between ∼40% and 41% (TIT = 550 °C).

Thermo-Economic Analyses and Comparisons of Two S-CO2-Brayton-Cycle-Based Combined Power Cycles for Concentrated Solar Power Plants

2018 ◽  
Author(s):  
Yuegeng Ma ◽  
Xuwei Zhang ◽  
Ming Liu ◽  
Jiping Liu
Keyword(s):  
Power Plants ◽  
Solar Power ◽  
Inlet Temperature ◽  
Brayton Cycle ◽  
Concentrated Solar Power ◽  
Power Cycles ◽  
Solar Power Plants ◽  
Cycle Efficiency ◽  
Concentrated Solar Power Plants ◽  
Residual Heat

In order to pursue superior cycle efficiency and lower power generation cost for the CSP plants, two S-CO2–Brayton–cycle–based power cycles with different utilization methods of the residual heat recover of the top S-CO2 Brayton cycle (SCBC) are investigated to seek alternatives to the stand-alone S-CO2 cycle as the power block of concentrated solar power plants. The residual heat released by the top S-CO2 cycle are either utilized to drive a LiBr absorption chiller (AC) for further chilling of the CO2 fluids exiting the precooler before entering the main compressor inlet temperature or recovered by an organic rankine cycle (ORC) for generating electricity. Thermo-economic analysis and optimization are performed for the SCBC–AC and SCBC–ORC, respectively. The results show that the thermal and exergetic efficiencies of the SCBC–AC are comparable with those of the SCBC–ORC in low pressure ratio conditions (PR<2.7) but are apparently lower than SCBC–ORC when PR is over 2.7. The LCOE of the CSP plant integrated with SCBC–AC is more sensitive to the change of PR. The optimal PR to maximum the cycle efficiency or minimize the plant LCOE for the SCBC–ORC is higher than that for the SCBC–AC, while the optimal recuperator effectiveness to minimize the LCOE of CSP plant integrated with SCBC–ORC is lower than that of SCBC–AC. The optimization results show that the thermo-economic performance of the SCBC–AC is comparable to that of the SCBC–ORC. Significant ηex improvement and LCOE reduction can be obtained by both the two combined cycles relative to the stand-alone S-CO2 cycle. The maximal ηex improvements obtained by the SCBC–ORC and SCBC–AC are 6.83% and 4.12%, respectively. The maximal LCOE reduction obtained by the SCBC-ORC and SCBC–AC are 0.70 ȼ / (kW·h) and 0.60 ȼ / (kW·h), respectively.

scholarly journals Effect of Pressure and Thermal Cycling on Compatibility in CO2 for Concentrated Solar Power Applications

2017 ◽  
Author(s):  
Bruce A. Pint ◽  
Robert G. Brese ◽  
James R. Keiser
Keyword(s):  
Solar Power ◽  
Base Alloy ◽  
Oxide Thickness ◽  
Small Mass ◽  
Reaction Products ◽  
Concentrated Solar Power ◽  
Scale Spallation ◽  
Power Cycles ◽  
Industrial Grade ◽  
Low Mass

A lifetime model is being developed for supercritical CO2 (sCO2) compatibility for the 30 year duty life for concentrated solar power (CSP) applications at >700°C to achieve higher efficiencies than other power cycles. Alloys 740H, 282, 625 and Fe-base alloy 25 are being evaluated in 500-h cycles at 1 bar and 300 bar, and 10-h cycles in 1 bar industrial grade CO2 at 700°–800°C. For comparison, companion experiments are being conducted in 1 bar air or O2. Using mass change, all of the alloys showed low mass gains with parabolic rate constants below the performance metric after 1000 h. However, alloy 25 showed a higher rate at 700°C in 300 bar sCO2 and did not follow an Arrhenius relationship. After 1500 h in 1 bar CO2, a much faster rate was observed for alloy 25 due to the formation of Fe2O3, but a similar increase was not observed in 300 bar CO2. Oxide thickness measurements have been completed after 1000 h in each condition. Only minor differences were noted between the 1 and 300 bar exposures. Up to 4,000 h exposures in 10-h cycles has not resulted in evidence of scale spallation but very small mass losses for alloy 625 were consistently observed. As longer exposures times are completed, quantification of the reaction products as a function time will be used to better model the degradation rate and additional characterization techniques will be included to further develop the model.

scholarly journals Capital Cost Assessment of Concentrated Solar Power Plants Based on Supercritical Carbon Dioxide Power Cycles

2019 ◽  
Vol 141 (7) ◽  
Author(s):  
Francesco Crespi ◽  
David Sánchez ◽  
Tomás Sánchez ◽  
Gonzalo S. Martínez
Keyword(s):  
Power Plants ◽  
Solar Power ◽  
Cost Effective ◽  
Capital Cost ◽  
Operating Conditions ◽  
Concentrated Solar Power ◽  
Power Cycles ◽  
Solar Power Plants ◽  
Major Equipment ◽  
Solar Field

Previous work by the authors has shown that broader analyses than those typically found in literature (in terms of operating pressures allowed) can yield interesting conclusions with respect to the best candidate cycles for certain applications. This has been tested for the thermodynamic performance (first and second laws) but it can also be applied from an economic standpoint. This second approach is introduced in this work where typical operating conditions for concentrated solar power (CSP) applications (current and future generations of solar tower plants) are considered (750 °C and 30 MPa). For these, the techno-economic performance of each cycle is assessed in order to identify the most cost-effective layout when it comes to the overnight capital cost (OCC). This analysis accounts for the different contributions to the total cost of the plant, including all the major equipment that is usually found in a CSP power plant such as the solar field and thermal energy storage (TES) system. The work is, thus, aimed at providing guidelines to professionals in the area of basic engineering and prefeasibility study of CSP plants who find themselves in the process of selecting a particular power cycle for a new project (set of specifications and boundary conditions).

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