Research On Capacity Ratio And Operation Mode Of Thermal Power Unit And Thermal Storage Peak Regulation

Flexible transformation of cogeneration units is an important means to increase the consumption level of wind power and other renewable energy.Mature wind abandonment absorption schemes do not need to carry out large-scale transformation of the turbine body,and mainly include heat storage tank scheme and electric boiler transformation scheme.These schemes are economical,flexible,widely used in engineering practice,and are effective in reducing the wind abandonment rate.Firstly,the current situation of wind power consumption capacity of a regional power grid in Northeast China is analyzed and studied,the electrothermal characteristic relationship of cogeneration units is established,the variable working conditions of the units are calculated,the maximum and minimum electrical loads of the units under the thermal load constraint conditions are obtained,and the peak adjustment range is determined.After the unit is equipped with electric boiler and heat storage tank,the depth peak regulation space obtained by the unit is related to the thermal load assumed by the unit.Generally,the month with higher thermal load,the depth peak regulation space obtained by the unit is also larger,and the corresponding optimal capacity of the electric boiler and heat storage tank in the month is also larger.Secondly,the thermoelectric characteristics,operation flexibility and peak shaving capacity of the unit equipped with heat storage tank and electric boiler are analyzed.At the same time,the operation mode and constraints of heat storage tank and electric boiler are analyzed.Under the peak shaving objective function,the optimal capacity of electric boiler and heat storage tank is calculated by characteristic day method.The results show that the maximum power of the electric boiler under the maximum peak shaving capacity is178.28 mw,and the maximum heat storage capacity of the heat storage tank is 1000 mwh.Since the optimal capacity of the heat storage tank is not determined by the maximum peak shaving increment and average peak shaving demand during the heating period,nor by the maximum heating load,but by the annual deep peak shaving space of the unit,the optimal heat storage capacity of the heat storage tank under the annual deep peak shaving space of the unit is 770 mwh.800mwh is the best heat storage capacity of the heat storage tank with the largest annual income regardless of the initial investment.However,if the initial investment of transformation is calculated,the optimal heat storage capacity is 430 mwh,and the corresponding 10-year profit index of heat storage tank is the largest.If the initial investment of electric boiler is calculated and the power is 170 MW,the profit index corresponding to 10 years is the largest.Then,according to the deviation of wind farm power generation and heat supply network load,the objective function of thermal power unit is analyzed,and the profit level,coal consumption level and environmental protection level under different consumption schemes are evaluated.For the average air rejection rate of 24.15%,in the same heating cycle,the air rejection rate of heat storage tank is reduced by3.72%,and that of electric boiler is reduced by22.57%.At the same time,under the condition of a certain coal consumption before the unit transformation,using the heat storage tank scheme in the same heating cycle can reduce the coal consumption by 0.25%,which is about 1172 tons.On the contrary,the coal consumption increased by 2.98% to 13698.24 tons.Finally,by analyzing the load deviation of heat supply network and wind farm,the wind power load and heating load are calculated ± Within the deviation range of 5%,it has little influence on the coal consumption level and abandoned air rate,but has great influence on the total income of peak shaving.