Rongrong Zhai

The Evaluation of Solar Contribution in Solar Aided Coal-Fired Power Plant

Solar aided coal-fired power plants utilize various types of solar thermal energy for coupling coal-fired power plants by using the characteristics of various thermal needs of the plants. In this way, the costly thermal storage system and power generating system will be unnecessary while the intermittent and unsteady way of power generation will be avoided. Moreover, the large-scale utilization of solar thermal power and the energy-saving aim of power plants will be realized. The contribution evaluating system of solar thermal power needs to be explored. This paper deals with the evaluation method of solar contribution based on the second law of thermodynamics and the principle of thermoeconomics with a case of 600 MW solar aided coal-fired power plant. In this study, the feasibility of the method has been carried out. The contribution of this paper is not only to determine the proportion of solar energy in overall electric power, but also to assign the individual cost components involving solar energy. Therefore, this study will supply the theoretical reference for the future research of evaluation methods and new energy resource subsidy.

Exergetic and Parametric Study of a Solar Aided Coal-Fired Power Plant

A solar-aided coal-fired power plant realizes the integration of a fossil fuel (coal or gas) and clean energy (solar). In this paper, a conventional 600 MW coal-fired power plant and a 600 MW solar-aided coal-fired power plant have been taken as the study case to understand the merits of solar-aided power generation (SAPG) technology. The plants in the case study have been analyzed by using the First and Second Laws of Thermodynamics principles. The solar irradiation and load ratio have been considered in the analysis. We conclude that if the solar irradiation was 925 W/m 2 and load ratio of the SAPG plant was 100%, the exergy efficiency would be 44.54% and the energy efficiency of the plant (46.35%). It was found that in the SAPG plant the largest exergy loss was from the boiler, which accounted for about 76.74% of the total loss. When the load ratio of the unit remains at 100%, and the solar irradiation varies from 500 W/m 2 to 1,100 W/m 2 , the coal savings would be in the range of 8.6 g/kWh to 15.8 g/kWh. If the solar irradiation were kept at 925 W/m 2 while the load ratio of the plant changed from 30% to 100%, the coal savings could be in the range of 11.99 g/kWh to 13.75 g/kWh.

Improved Optimization Study of Integration Strategies in Solar Aided Coal-Fired Power Generation System

Solar aided coal-fired power generation system (SACFPGS) combines solar energy and traditional coal-fired units in a particular way. This study mainly improves the solar thermal storage system. Genetic algorithm is used to optimize the SACFPGS. The best integration approach of the system, the collector area, and the corresponding thermal storage capacity to replace each high-pressure extraction are obtained when the amount of coal saving in unit solar investment per hour is at its largest. System performance before and after the improvement is compared. Results show that the improvement of the thermal storage system effectively increases the economic benefit of the integrated system.

Integration and evaluation of a power plant with a monoethanolamine-based CO2-capture process

Background: In this article, the integration of a 600-MW supercritical power plant with a monoethanolamine-based CO2-capture process has been studied. Methodology: Technical evaluation has been performed on nine cases. The effect of the fraction of CO2 captured and energy required for CO2 capture has also been analyzed. Results: When the system is configured so that more steam is extracted from the low-pressure turbine, modeling shows that this system has the highest thermal efficiency, approximately 41.92% reduced by 3.22% compared with the thermal efficiency of the original power plant. Conclusion: The results are useful for finding the optimal configuration of the integration between a coal-fired power plant and CO2-capture process.

Consumption analysis of Solid Oxide Fuel Cells

The characteristics of the Solid Oxide Fuel Cell (SOFC) were introduced. The SOFC system can be divided into ten sections based on the Second Law of Thermodynamics. The fuel specific consumption was taken as the primary indicator to investigate the specific consumption for each section. The Energy-flow Framework Diagram (EFD) was undertaken to modify the system, such as controlling the operating temperature and strengthening insulation. It is concluded that the specific consumption of the system is about 0.19 m³/kWh, taking great guidelines for the system improvement.