Configuration method for combined heat and power plants with flexible electricity regulation

Abstract

A net-zero emissions target has been set as the long-term climate goals by many countries and regions. Efficient utilization of renewable energy is an essential way to solve energy and environmental problems. China needs to change its fossil-based energy mix and achieve a deep low-carbon transition in the energy sector. The future development of thermal power plants is focused on improving the power peak-shaving capacity while ensuring a heating supply with economical and feasible methods. This study presents a reasonable evaluation model to analyze different cogeneration plant power peak shaving modes. It proposes an optimal configuration method for combined heat and power generation plant power peak shaving systems by combining their characteristics and applicability. The basic principle of this method is that the most profitable mode for each power peak-shaving depth must be selected to achieve the best overall economic benefit of the system. The absorption heat pump waste heat recovery method, the electric heat pump waste heat recovery method and the electric boiler method are suitable for bearing the base load, waist load and peak load of the power peak shaving, respectively. The analysis results of influence economic factors show that as the heating price of the alternative heat source increases, the electric heat pump waste heat recovery method assumes a larger capacity for power peak shaving. When the heating price of alternative heat sources is 30 yuan/GJ (about the heating cost of a coal-fired boiler) and 100 yuan/GJ (about the heating cost of a gas-fired boiler), the electric heat pump waste heat recovery method should bear the depth peak-shaving demand with the duration higher than 360 h and 110 h respectively.