Study On The Coordinated And Optimal Dispatching Of Thermal Power Plant With Multiple Energy Supply Modes

At present,it is difficult to absorb wind power in "Three North" regions,and the contradiction between heat and power during heating period is becoming more and more prominent.As the main participant in the peak shaving system,the 300MW-class unit has undergone flexible transformation.It is of practical engineering significance to carry out research on the coordination and optimization of electricity and heat for thermal power plants that have completed the transformation.In response to the above problems,this article has mainly done the following two aspects:(1)This article took a 300MW-class heating unit as an example,used Ebslion to build a simulation model,and calculated the peak shaving capacity of the extraction condensate heating unit.Aiming at the problem of insufficient peak regulation capacity of the condensing unit during the heating period,four flexible transformation schemes were introduced,mainly including the transformation scheme of the unit itself(high back pressure heating transformation HBP,low pressure cylinder removal transformation LCPP)and integrated heat source equipment scheme(Electric boiler EB,electric heat pump EH-P),and carried out simulation calculation according to the transformation principle.The results showed that the unit with coupled heat source equipment has the highest flexibility.Compared with the unit with coupled electric heat pump heating,the coupled electric boiler has higher flexibility,wider load adaptability,and stronger peak regulation ability;The pressure transformation plan increases the heating capacity of the unit,but the electrical and thermal coupling is enhanced,and other heating modes need to be combined to improve the flexibility of the unit during the heating season.(2)For a flexible retrofit power plant,a study on the decision-making of the combined operation mode of thermal power plant units was carried out,and the combined operation energy supply mode under different thermal load periods was determined through simulation calculation:under the heat load of the whole plant,the on-grid power load of the whole plant is 250MW as the boundary,under the low heat load of the whole plant,when the on-grid power load is higher than 250MW,the mode 3 shall be adopted,otherwise the mode 1 shall be adopted;When the on-grid power load is higher than 250MW,it is recommended to adopt mode three,otherwise,adopt mode two;under high total plant heat load,the on-grid power load is higher than 250MW,then it is recommended to adopt mode three,and when the on-grid power load is higher than 250MW,it is recommended to adopt mode 2.(3)For different operation combination modes,this paper established a plant-level load optimization model with the minimum total coal consumption and the minimum total cost in the optimization period as the objective function.It also analyzed the operation combination mode under actual examples.Optimization potential.The results show that the HBP+EH combined operation mode has great optimization potential,and the optimization potential becomes more obvious with the increase of electricity and heat load;the operation mode of the coupled electric boiler can not only adapt to different heating loads,but also has higher flexibility.The minimum load of the unit can be connected to the grid,and the zero-power output of the unit can be connected to the grid under extreme conditions.Under the auxiliary subsidy policy,the investment ratio of electric boilers can be appropriately increased.