Analysis Of The Flexibility Of The Heating Unit With The Heat Storage Device

With the large-scale grid-connected power generation of renewable energy power,and the increasing power load,the peak difference of power valleys is increasing,making the peaking and frequency regulation of power systems more and more difficult.The traditional peaking mechanism can not meet the requirements of the power grid.However,thermal power generation in China's power and energy structure still dominates.By configuring the heat storage device,the rapid load capacity of the heating unit can be well improved.This paper aims to study the measures and means to improve the flexibility of the heating unit.Based on the in-depth analysis of the characteristics of the heating unit and the characteristics of the heat storage unit,the influence of the heat storage unit on the rapid load capacity of the heating unit is analyzed.This paper analyzes the flexibility of the heat storage unit with heat storage unit in the following aspects:(1)The novel phase change material acts as a heat storage medium by utilizing the advantages that the latent heat temperature of the molten salt phase transition is approximately constant and the heat capacity is large.According to the heat transfer mechanism,the dynamic simulation model of t he heat storage device is established,and the temperature distribution,heat storage and heat storage efficiency in the process of heat storage and heat release are obtained.(2)Using Aspen simulation software to build a steady-state process model and a heat storage device model of a 300 MW heating unit,and compare the heat consumption rate of different coupling modes to analyze the thermal economy of the condenser-type heating unit after the heat storage device is configured.The results show that the use of mixed extraction steam during heat storage and the high extraction and extraction coupling during heat release have the least impact on the economics of the unit.(3)By analyzing the variation laws of each major thermal equipment,the mathematical model of fluid network calculation,the dynamic mathematical model of steam turbine unit,condenser,heater and desecrator are established.A dynamic simulation system model integrating the condenser heating unit and the heat storage device is constructed,and the load change effect of the heat storage unit on the heating unit is analyzed based on the coordinated control.The results show that the load response rate can be significantly increased to 2.2~3.03Pe/min after the heating unit is used to accumulate the energy storage function,which can effectively alleviate the pressure caused by large-scale grid-connected power generation of renewable energy.For a 300 MW pumping-type heating unit,only the “two rules” assessment can increase the income by 170,000 yuan per month.