Study On Smart Heat Supply Strategy And Disturbance Propagation Characteristics Of Heat Networks Based On Standard Thermal Resistance

In the context of the dual carbon strategy,in order to meet the diverse heat load requirement.it is vital to continuously reduce the energy consumption of the heating system and steadily improve the quality of the heat supply.The heating system is characterised by large variations in ambient temperature,many internal disturbances and complex customer demands,and the system is coupled with source-grid-load and has multiple components.processes and parameters.Therefore,the construction of an overall analytical model of the heating system and the optimization of the heating strategy are the basis for efficient and flexible heating.This paper constructs a dynamic heat current model of the heating system and analyses its dynamic characteristics based on standard thermal resistance and using the heat current modelling method of dynamic heat current,proposes an energy-efficient and intelligent heating strategy,and proposes counter strategies for common disturbances in the system to improve the stability of the heating system.Based on the standard thermal resistance method,the dynamic heat transfer processes between the hot fluid and the cold fluid in the heat exchanger,the pipe and the soil,the radiator.the indoor air and the external environment are analysed from the viewpoint of linear heat transport using the heat current method for the main equipment in the heat exchange station.the heating pipes and the building containing radiators;combined with the methods of transmission delay and thermoelectric comparison,we constructed the dynamic thermal power flow models for the pipes,the heat exchanger and the building containing radiators.Based on the work topology of the heating system,constructed the dynamic heat flow topology model of the multi-process coupling of the heating system,and the simulation modelling is carried out using Fluent software to verify the accuracy of the dynamic model.The heat transfer delay distribution characteristics of the components in the heating system are elucidated by quantifying the time constants.Applying the constructed dynamic heat current model of the system and considering the user behaviour,an intelligent control strategy for time-by-time qualitative and quantitative regulation of the primary network that integrates outdoor temperature,system thermal inertia and transmission delay is developed in conjunction with an iterative method,and corresponding heating strategies are formulated for different demands such as multiuser series connection and multi-user parallel connection.The smart heating strategy for user-following strategy can save up to 25.3%of energy,which provides a new theoretical basis and solution for the intelligent operation of heating systems.Based on the propagation mechanisms and characteristics of different disturbances,combined with automatic control theory,the feasible control means for the heat network and load side are sorted out for different disturbances and their effects on the heat supply network,and five types of disturbances,such as user behaviour and pipe leakage,are established as the first goal to guarantee the thermal comfort of users.A disturbance control method based on blockers is also proposed to provide new ideas for multi-user disturbance control.