Study On Increasing Peak Load Capacity Of Heating Units By Using Heat Storage Technology In Heat-supply Network

In recent years,new energy,such as wind energy and solar energy,which have been developing rapidly,participate in grid connection on a large scale,bu t because of its own instability,the security of power grid regulation and operation is reduced.This problem has become particularly serious in winter in northern China,because a large amount of superheated steam must be extracted from the medium pressu re cylinder of the heating unit during heating period to meet the needs of thermal users,but it has greatly limited the peak-shaving and frequency-regulating capacity of thermal power units.In this paper,based on the design data provided by steam turbine manufacturers,taking different types of heat supply units as the research object,the simulation model of heat supply units is established by using EBSILON simulation software,and the reliability of the model is verified by comparing the simulation res ults with the known data.Secondly,based on needs,By resetting the parameters of the built simulation model and calculating the off-design conditions,the peak-shaving ranges of different types of heat-supply units under different extraction volumes are obtained.Further,the peak-shaving ranges of heat-supply units under different heating areas and ambient temperatures are predicted for a specific unit.Finally,in order to improve the peak-shaving ability of heat-supply units by thermoelectric decoupling method,hot water storage tanks are coupled in the heat network,and two kinds of heat storage regulation modes are proposed.The heat storage capacity including the heat storage capacity required by the heat storage tank when the heating unit stops supplying heat to the outside world,heat release rate of heat storage tanks under different heat storage regulation modes are obtained.And the thermal economic analysis is carried out to determine the optimal peak shaving scheme.The calculation results of an example prove that the peak-shaving simulation model of heating units proposed in this paper has certain reliability.The relative error between the simulation results and the actual operation data is less than 5%.On the basis of the model,the peak-shaving ranges of heat-supply units under different heat-supply extraction quantity,heat-supply area and ambient temperature are predicted.The two heat storage regulation modes proposed in this paper can meet the load requirements of the heat network and the power network.From the perspective of heat release,the average heat release rate of the storage tank in the second heat storage regulation mode is higher than that of the storage tank in the first heat storage regulation mode,but the setting requirement of the storage tank in the second heat storage regulation mode is higher.From the perspective of thermal economy,the equivalent coal consumption rate of the second heat storage regulation regulation mode is lower and the economy is better under the same conditions.At the same time,it is found that the coal consumption rate is not affected by the amount of extraction steam,but affected by the main steam flow,the larger the main steam flow,the lower the coal consumption rate,and under the condition of the larger the main steam flow,the energy saving effect of the heating unit is better than that of the pure condensation unit.