Research On Flexibility Of 600MW Cogeneration Units Using Thermal Network Energy Storage Characteristics

With the rapid development of new energy power in China,when new energy such as wind power with certain randomness and volatility is connected to the grid on a large scale,the grid side is subject to strong impact,which is not conducive to the safe operation of the power system.Especially in the "Three North" region,the phenomenon of abandoning wind and abandoning photovoltaics has become increasingly serious.Therefore,it is particularly important to actively develop traditional power generation technologies represented by coal-fired power generation to actively assist new energy consumption.The more important thing is to fully exploit and utilize the energy storage links of thermal power units.Related research shows that in the northern part of China,the cogeneration unit accounts for more than 35%of the total generator assembly capacity,and its associated heating pipe network and its ancillary buildings have great energy storage capacity and thermal inertia,and are short.Time to use thermal network energy storage does not have a noticeable impact on hot users.Therefore,research on the operation characteristics,load characteristics and thermal network energy storage characteristics of heating units is of great significance for improving the flexibility of the unit and suppressing the impact of large-scale grid-connected power sources with high randomness such as wind power.This paper takes the 600MW cogeneration unit of a power plant in Inner Mongolia as the object,and carries out the refined modeling of the variable load process of the unit based on the relevant data,and verifies and corrects the operation characteristics and load response characteristics of the unit during the heating period.The influence of the change of steam extraction on the main steam parameters,power output and energy consumption level of the steam turbine,the influence of the heating steam extraction flow rate,the extraction steam pressure and the main steam parameter on the unit efficiency in different boiler evaporation quantities,complete the unit Study on the characteristics of variable working conditions during heating period,and then obtain the load response characteristics of the units under various operating modes;study and analyze the heat network by fully collecting and analyzing the data of heat extraction,heat supply,return water temperature and user side temperature of thermal power plants And the themiodynamic dynamic characteristics and energy storage potential of the user side;study the exact correspondence between the local steam extraction and the transient load change of the unit under typical conditions of the heating period,and the heating of the heating network under this dynamic control The law of change of effect is proposed,and the optimization strategy of peak response mechanism is proposed.Finally,the AGC response system and CCS system for unit are proposed.Operating logic optimized implementation and evaluation of programs thermodynamics.Through the above research and analysis,and the optimization program in the power plant for on-site simulation.The results show that this scheme can effectively improve the flexibility of the unit and increase the variable load rate by 0.5-1.2%Pe/min on the original basis,which can effectively alleviate the large-scale grid connection of new energy power to the power grid pressure.