Production Simulation Research On The Combined Heat And Power System Considering Power-Heat Synergy

In recent years,with the proposal of the "carbon peaking and carbon neutrality goals",the construction of new power systems has been continuously promoted in China,and renewable energy represented by wind power and solar photovoltaic(PV)has developed rapidly,the intermittency and volatility of wind power and solar PV generation increases the demands on system flexibility.At the same time,China’s existing traditional coal power is large in scale and new in age,facing severe transformation pressure,and must accelerate the transition to become flexible power sources.At present.the trend of cogeneration of coal-fired power units in China is significant,and the flexibility transformation is the most economical and effective measure to enhance the flexibility of the power system.Considering the huge scale of China’s existing coal power units,it is urgent to step up the study of the flexibility retrofit path of China’s coal power units.Especially for combined heat and power(CHP)units,by configuring heat storage,electric boilers and other equipments for "heatpower decoupling(HPD)",deep peak shaving and electricity and heat coordination of the units can be achieved,and effectively serve the development of a high proportion of renewable energy in China.This paper focuses on the technical perspective of coal power flexibility retrofit,studies the characteristic changes and refined output modeling of coal-fierd CHP units before and after HPD.constructs a production simulation method to analyze the impact of HPD retrofit on the operation and flexibility of power system,and proposes a coal power flexibility retrofit path suitable for local characteristics with an example of a certain place in China,so as to provide suggestions for the transformation and development of coal power in China.The main work of this paper is as follows:From the perspective of coal power unit flexibility retrofit,the HPD research of coal-fired CHP unit side by the configuration of heat storage tank and electric boiler is carried out:Firstly,the output characteristics and cost changes of traditional coal power units including CHP units are analyzed;Then,the application of heat storage tank and electric boiler in the CHP unit retrofit is focused on,the electro-thermal characteristics after the retrofit are systematically analyzed,and the corresponding decoupling output models of units are established;Finally,the validity of the proposed HPD model is verified through an example,and the effect of HPD on the flexibility improvement of CHP unit is analyzed.Combining with the established HPD model of the unit,considering the relevant constraints of power and thermal systems and the effects of heat delay and heat loss in thermal energy transmission,a comprehensive production simulation method for combined heat and power system considering heat-power decoupling of CHP units is established;The impact of HPD retrofit on the operation of CHP system is systematically studied,and the system flexibility and improvement of wind and solar curtailment brought by flexibility retrofit are analyzed.Using the constructed HPD model and production simulation method,this section focus on the actual operation of the power system in a peaking difficulty region in China.The impact of HPD on wind,solar curtailment and economics in the region is analyzed,a flexibility retrofit path of coal-fired CHP unit suitable for local characteristics is proposed,and it is used as a demonstration to provide policy recommendations for the coal power flexibility transformation in China.