General performance evaluation method of integrated solar combined cycle (ISCC) system

The integrated solar combined cycle (ISCC) system is a proven solution for grid-connected power generation from solar energy. How to further improve the ISCC system efficiency and propose a more efficient system solution has become a research focus. A novel gas turbine combined cycle (GTCC) benchmark system is proposed by replacing the conventional steam Rankine bottom cycle with a supercritical CO2 Brayton cycle, whose output power and efficiency are increased by 9.07 MW and 1.3%, respectively, compared to those of the conventional GTCC system. Furthermore, the novel ISCC systems are established with the parabolic trough solar collector (PTC) and the solar tower (ST) collector coupled to the novel GTCC system. Thermal performance analysis, exergy performance analysis, and the sensitivity analysis of the ISCC systems have been performed, and the results show that the system efficiencies of both ISCC systems are lower than that of the GTCC system, at 57.1% and 57.5%, respectively, but the power generation of the ISCC system with PTC is greater than that of the benchmark system, while that of the ISCC system with ST is less than that of the benchmark system. The photoelectric efficiency of the ISCC system with PTC is 27.6%, which is 2.1% greater than that of ISCC system with ST. In the ISCC system with PTC, the components with the highest exergy destruction and the lowest exergy efficiency are the combustion chamber, and PTC, respectively. ST is the component with the highest exergy destruction and the lowest exergy efficiency in the ISCC system with ST. With the increase in direct normal irradiance (DNI), the total output power, solar energy output power, and photoelectric efficiency of the ISCC system with PTC increase, while the system efficiency decreases; the solar energy output power and photoelectric efficiency of the ISCC system with ST increase, while the total output power and system efficiency decrease. The photoelectric efficiency of the ISCC system with PTC is greater when the DNI is greater than 600 W/m2; conversely, the photoelectric efficiency of the ISCC system with ST is greater. After sensitivity analysis, the optimal intercooler pressure for the ISCC system is 11.3 MPa.

Comprehensive evaluation of integrated solar combined cycle system regarding fuel-savability under unified framework

High performance integrated solar combined cycles with minimum modifications to the combined cycle power plant design

10 - Integrated solar combined cycle (ISCC) systems

Modeling and numerical simulation of an Integrated Solar Combined Cycle System in Algeria

Integrated solar combined cycle (ISCC) system, which integrates solar thermal energy into traditional gas turbine combined cycle (GTCC) system, has become an efficient way to reduce the levelized cost of electricity (LCOE) and improve the thermal efficiency of the GTCC system. However, the volatility of solar energy usually results in low ISCC system thermal efficiency when no or low direct normal irradiance (DNI) is available because the ISCC system is usually not equipped with thermal energy storage system. In this paper, the ISCC system with a new operation strategy of changeable integration mode under different DNI conditions is proposed. The ISCC system model is constructed using the EBSILON software. Performance of ISCC system using the new operation strategy is investigated deeply. The results show that the ISCC system using the new operation strategy has higher annual solar to electricity efficiency (19.08%), 1.1% higher than that of the traditional ISCC system. Due to different DNI distributions in a whole year, the larger the distribution proportion of the low‐value DNI is, the greater the thermodynamic performance advantage of ISCC system with the optimization strategy is. Through the economic performance analysis, the LCOE of the ISCC system with the new optimization strategy is 0.223 $/kW·h, 0.01 $/kW·h lower than that of the traditional ISCC system. The LCOE decreases at first and then increases with the increase of the number of the parabolic trough collector. The optimal number of the parabolic trough collector corresponding to the new optimization strategy is 500. So this new operation strategy provides a new way for adequately utilizing the solar energy in ISCC system.

Solar Trough Integration Into Combined Cycle Systems

Parabolic trough power plants have several concepts for production energy, these concepts are developed by Solar Electric Generating System (SEGS) and Direct Solar Steam (DISS) project for research and development, the SEGS is developed the integrated solar combined cycle system (ISCCS), however in recent years the DISS project with direct steam generation (DSG) technology proves the evaluation from the cost, the process control and the easy erection in construction. There are many studies developed in the solar hybrid power plants system for ISCCS and DSG, in this paper will be evaluated these models of solar hybrid system compound a natural gas combined-cycle backup for solar thermal energy, taken into account the thermodynamic analyses and techno-economic assessment for each concept of the ISCCS and DSG plants. These models evaluated in this work will be simulated with TRNSYS program and SAM System Advisor Model. This analysis was conducted to get the performance in these concepts and shows the lower levelized energy cost (LEC), so to increase to the electricity net efficiency in solar contribution of the power plants.

In this research, a malfunction diagnosis method based on the enhanced exergy concept is applied to quantify the anomalies' sources in a real integrated solar combined cycle system (ISCCS). A comprehensive parametric study is performed to evaluate the malfunction indicators and the overall performance of the power plant by varying the substantial operating parameters under single and multi-malfunction conditions. Then, the fast and elitist non-dominated sorting genetic algorithm (NSGA-II) is applied to maximise the net power and minimise the total exergy destruction rate of the system under a multi-malfunction condition.

This paper compares the annual performance of Integrated Solar Combined Cycles (ISCCs) using different solar concentration technologies: parabolic trough collectors (PTC), linear Fresnel reflectors (LFR) and central tower receiver (CT). Each solar technology (i.e. PTC, LFR and CT) is proposed to integrate solar energy into the combined cycle in two different ways. The first one is based on the use of solar energy to evaporate water of the steam cycle by means of direct steam generation (DSG), increasing the steam production of the high pressure level of the steam generator. The other one is based on the use of solar energy to preheat the pressurized air at the exit of the gas turbine compressor before it is introduced in the combustion chamber, reducing the fuel consumption. Results show that ISCC with DSG increases the yearly production while solar air heating reduces it due to the incremental pressure drop. However, air heating allows significantly higher solar-to-electricity efficiencies and lower heat rates. Regarding the solar technologies, PTC provides the best thermal results.

This paper presents the implementation of an integrated solar combined cycle (ISCC) on the existing 44 MW Cameo Power Generating Station, located in Palisade, Colorado. The plant was originally built in 1957 as a coal fired power plant, to serve the Grand Junction community. This plant has been chosen to demonstrate the viability of the ISCC because of its time line to decommissioning and the availability of additional power from nearby stations to fulfill the community’s needs. The solar system at Cameo utilizes 8 aluminum parabolic trough collectors arranged in 4 loops. Each of these collectors is approximately 150 meters long and 5.77 meters wide. The hot heat transfer fluid used in the solar field is sent to a solar feed water heater, located in between two of the existing feed water heaters, to supplement the thermal energy required by the steam cycle. At design conditions, the solar field will provide 4 MW of thermal energy to the power plant. The development of this ISCC has faced several design and construction challenges not common in traditional power plant and solar power plant design. When first constructed, the Cameo station had no provisions made regarding solar field location, heat transfer fluid piping runs, heat transfer fluid pumping station, thermal expansion vessels, the addition of solar thermal energy to the feed water system, and the integration of a solar field control system into the existing plant distributed control system. Also unaccounted for are the affects the integration of a solar feed water heater has on the thermodynamic efficiency of the steam cycle. This paper discusses these challenges, as well as their resolution, as seen during the engineering, procurement, construction, and commissioning phases of this project. The Cameo Power Generating Station is located in the DeBeque Canyon, 4 miles east of Palisade, Colorado along the Colorado River and Interstate 70. The solar feed water heating demonstration will be in operation for 1 to 2 years, at the discretion of Xcel Energy, to test and develop operating and maintenance methods for large scale application. After such time, both the plant and the solar field will be decommissioned. After decommissioning all applicable solar field equipment shall be refurbished and utilized at additional testing facilities.

A performance evaluation of an integrated solar combined cycle power plant with solar tower in Saudi Arabia

Solar desalination tower, novel design, for power generation and water distillation using steam only as working fluid

Aspen Plus simulation of biomass integrated gasification combined cycle systems at corn ethanol plants

Gas turbine power generation has the advantages of flexibility, efficiency, and lower carbon emissions compared with coal-fired power generation. Under the situation of energy structure transformation and upgrading, gas turbine power generation will have bright prospects. In this paper, the modeling and thermodynamic analysis of various gas-supercritical carbon dioxide(sCO2) combined cycle systems are carried out based on the calculation method of total physical properties, and six typical combined cycle layouts are selected for detailed research. In order to obtain the optimal state of the combined cycle system, the parameters of the sCO2 bottom cycle are optimized within a certain range of the gas turbine pressure ratio. It is found that the combined cycle system has high thermal efficiency when the top cycle adopts the air preheating cycle, and a higher top cycle regenerative degree does not represent a better performance. In fact, the optimal regenerative degree is related to the bottom cycle performance. The study also found that the air preheating-dual heated cascade combined cycle system has the highest thermal efficiency of the layouts studied, reaching 65.3%, but it comes at the cost of a complex operating system. The heat recovery performance of the sCO2 partial heating bottom cycle is relatively poor, and its mass flow rate is the highest, so it is not suitable for the bottom cycle of the combined cycle. The sCO2 dual heated cascade cycle has the highest output work and the smallest CO2 flow, so this paper considers this bottom cycle as the most suitable bottom cycle for the combined cycle system. This research can provide a certain basis for the design of gas turbine combined cycle system.