Energy- and exergy-based performance evaluation of solar powered combined cycle (recompression supercritical carbon dioxide cycle/organic Rankine cycle)

Two combined cycle engine cascade concepts are presented in this paper. The first uses a traditional open loop gas turbine engine (Brayton cycle) with a combustor as the topping cycle and a series of supercritical carbon dioxide (S–CO2) engines as intermediate cycles and a bottoming cycle. A global optimization of the engine design parameters was conducted to maximize the combined efficiency of all of the engines. A combined cycle efficiency of 65.0% is predicted. The second combined cycle configuration utilizes a fuel cell inside of the topping cycle in addition to a combustor. The fuel cell utilizes methane fuel. The waste heat from the fuel cell is used to heat the high pressure air. A combustor is also used to burn the excess fuel not usable by the fuel cell. After being heated, the high pressure, high temperature air expands through a turbine to atmospheric pressure. The low pressure, intermediate temperature exhaust air is then used to power a cascade of supercritical carbon dioxide engines. A combined efficiency of 73.1% using the fuel lower heating value is predicted with this combined fuel cell and heat engine device. Details of thermodynamics as well as the (S–CO2) engines are given.

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Design Optimization of Plate-Fin Heat Exchanger in a Gas Turbine and Supercritical Carbon Dioxide Combined Cycle with Thermal Oil Loop

Applied Sciences ◽

10.3390/app12010042 ◽

2021 ◽

Vol 12 (1) ◽

pp. 42

Author(s):

Yue Cao ◽

Jun Zhan ◽

Jianxin Zhou ◽

Fengqi Si

Keyword(s):

Heat Transfer ◽

Carbon Dioxide ◽

Genetic Algorithm ◽

Heat Flux ◽

Supercritical Carbon Dioxide ◽

Pareto Frontier ◽

Combined Cycle ◽

Nsga Ii ◽

Thermal Oil ◽

Supercritical Carbon

This paper presents an investigation on the optimum design for a plate-fin heat exchanger (PFHE) of a gas and supercritical carbon dioxide combined cycle which uses thermal oil as intermediate heat-transfer fluid. This may promote the heat transfer from low heat-flux exhaust to a high heat-flux supercritical carbon dioxide stream. The number of fin layers, plate width and geometrical parameters of fins on both sides of PFHE are selected as variables to be optimized by a non-dominated sorting genetic algorithm-II (NSGA-II), which is a multi-objective genetic algorithm. For the confliction of heat transfer area and pressure drop on the exhaust side, which are the objective indexes, the result of NSGA-II is a Pareto frontier. The technique for order of preference by similarity to ideal solution (TOPSIS) approach is applied to choose the optimum solution from the Pareto frontier. Finally, further simulation is performed to analyze the effect of each parameter to objective indexes and confirm the rationality of optimization results.

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Performance investigation of the solar power system using cascade supercritical carbon dioxide Brayton-steam Rankine cycle

10.46855/2020.06.18.10.44.591951 ◽

2020 ◽

Author(s):

Gang Pei ◽

Honglun Yanga ◽

Jing Lib ◽

María Rodríguez-Sanchezc ◽

Domingo Santanac ◽

...

Keyword(s):

Carbon Dioxide ◽

Supercritical Carbon Dioxide ◽

Power System ◽

Solar Power ◽

Rankine Cycle ◽

Supercritical Carbon

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Development of Turbine and Combustor for a Semi-Closed Recuperated Brayton Cycle of Supercritical Carbon Dioxide

Volume 1: Boilers and Heat Recovery Steam Generator; Combustion Turbines; Energy Water Sustainability; Fuels, Combustion and Material Handling; Heat Exchangers, Condensers, Cooling Systems, and Balance-of-Plant ◽

10.1115/power-icope2017-3419 ◽

2017 ◽

Cited By ~ 3

Author(s):

Takashi Sasaki ◽

Masao Itoh ◽

Hideyuki Maeda ◽

Junichi Tominaga ◽

Daizo Saito ◽

...

Keyword(s):

Carbon Dioxide ◽

Supercritical Carbon Dioxide ◽

New Technologies ◽

Combined Cycle ◽

Working Fluid ◽

Brayton Cycle ◽

The Usa ◽

Demonstration Plant ◽

Competitive Efficiency ◽

Supercritical Carbon

Toshiba has been developing a turbine and a combustor for a semi-closed recuperated Brayton cycle of supercritical carbon dioxide called the Allam cycle, which is capable of both sequestrating 100% of carbon dioxide generated by combustion and providing electricity with competitive efficiency as the advanced combined cycle. The 25 MWe class demonstration plant with natural gas for this innovative cycle is being constructed in the USA by NET Power LLC and its operation is expected to be in 2017. Toshiba is going to provide the main components of its turbine and combustor. This paper describes the specification of the turbine and the combustor and consideration necessary to realize them in the first of a kind design condition of 30MPa with a supercritical carbon dioxide as its working fluid. This paper also describes some of the validation tests to realize new technologies before this turbine and combustor are installed and operated in the demonstration plant.

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