Study On Power-heat-cool Combined Scheduling Method For Gas-steam Combined Cycle System

There is a lack of hydropower units in the "three north" area,mainly thermal power units,and a large proportion of the combined heat and power units.In recent years,after the rapid growth of wind power installed capacity,there have been many problems such as the difficulty of wind power consumption and serious environmental damage.In order to reduce pollution,large northern cities such as Beijing and Tianjin are actively developing the "coal to gas" technology,replacing the combined heat and power units with gas-steam combined cycle units.In this paper,the issues of gas-steam combined cycle unit modeling,combined heat and power system scheduling problem,impact on wind power consumption,and multi-energy system scheduling problem involving cold-heat-power after the implementation of the "coal-to-gas" project are studied.Firstly,based on the detailed analysis of the working principle and process flow of the gas-steam combined cycle unit,the combined heat and power unit,the cold-heat-power unit model of the gas-steam combined cycle unit is constructed,which provided a theoretical basis for follow-up research.Secondly,based on the objective function of minimum system cost,an optimization scheduling model of the combined heat and power system including the gas-steam combined cycle unit,the pure condensing thermoelectric unit,the combined heat and power unit,the wind power unit,and the peaking electric boiler is constructed,and particle swarm algorithm is studied.Through example simulations,the effects of the "coal to gas" program,the scale of “coal to gas” conversion,and the penetration rate of wind power on the wind power consumption rate of the grid were compared and analyzed.Finally,an overall structure of a multi-energy system with input of primary energy such as coal,wind energy,gas,and hydropower,and output of conventional secondary energy such as electricity,heat,and cold,is constructed.A mathematical of multi-energy coupled components and a multi-energy system scheduling model involving cold-heat-power have been established.The effects of the “coal to gas” scheme,heat load and cooling load on the cost of the multi-energy system involving cold-heat-power and the wind power abandonment rate are compared and analyzed.Theoretical analysis and example simulations show that replacing the the combined heat and power unit with the gas-steam combined cycle unit increases operating costs,but it is beneficial to the system's wind power consumption,and the larger the “coal-to-gas” conversion rate,the better effect of wind power consumption,but the increase in wind power penetration rate will increase the rate of wind abandonment rate.The integration and coordination of multi-energy systems can increase the wind power consumption rate.After the “coal to gas” program is implemented,the operating costs of the multi-energy system involving cold-heat-power increase,and the wind power abandonment rate decreases.With the increase of heat load and cooling load,the total cost of the multi-energy system involving cold-heat-power and the rate of wind power abandonment rate have increased.