Research On Energy Saving Control Method Of Secondary Network For Central Heating System

With the development of economy and the improvement of people’s life quality,energy saving and environmental protection have attracted great attention from country and society. Some developed countries share similar climate with China, while the energy consumption of unit area our country consumes in central heating system is about 3 times more than that of other countries consume at present. Thus comes to the conclusion that a controlled central heating system guarantees considerable energy saving. Increasing the efficiency of heating system and proposing effective energy saving measures are two keys to the development of Chinese central heating system.As an important part of central heating system, the secondary network for central heating system is a multi-variable, strong coupled and long delay system. Thus, the main research this article presents is saving control method of secondary network for central heating system. The methods, solving the strong coupled feature, are aiming at not only meeting the heating need from users but also realizing accurate controlling to the greatest extent then saving energy.In light of the inability to operate long-term steadily which due to the coupling phenomenon between control circuit of secondary supply water temperature and secondary backwater temperature of central heating system, a control strategy based on internal model decoupling is proposed to satisfied the needs of secondary supply water temperature and secondary backwater temperature.This article summarizes the energy saving technologies our country adopted in central heating system, including the connection types of central heating system,heating network, water pump and so on.This article studies detailedly the relationship between secondary supply water temperature and primary water flow、secondary water flow,the relationship between secondary backwater temperature and primary water flow、secondary water flow, establish the two input two output coupling model structure of secondary supply water,backwater temperature and water flow of heating process.The particle swarm optimization algorithm is improved to identify model parameters in the coupling model of secondary supply water temperature and secondary backwater temperature. Finally, a mathematical model of secondary supply water temperature and secondary backwater temperature of central heating system is confirmed.According to the strong coupling characteristic of secondary network for central heating system, this research analyzes every decoupling method available at present, then proposes a method of internal model decoupling control method. The internal modelcontrol has the advantage of strong ability to resist interference when a slight variation exists in model parameters. However, there is a parameter in the internal model control which influence dynamics characteristic of control system directly. And this parameter is unique and adjustable. Combine this property with single neuron comes to a single neuron internal model decoupling controller. Correct the parameter with single neuron real-time and on-line, finally realize the adaptive control of the system. Comparing these two algorithms, the simulation shows both regular internal model decoupling control and single neuron internal model decoupling control could realize the decoupling control of secondary supply water temperature and secondary backwater temperature when matching model, and they have similar results. When the model mismatch, the latter method is better in accommodation time, in other words single neuron internal model decoupling control shows faster response speed, stronger robustness and better adaptive ability. On account that the secondary supply water temperature and secondary backwater temperature have different setting values according to different environmental condition, the decoupling control is necessary to guarantee an accurate setting value.