The Operating Regulation Strategy For Heat Metering In The Branch Network With A Single Heat Production Plant

The central heating system in China has been controlled by planned economy for a long time, which caused energy resource waste, low efficiency of the heating supply enterprise and bad effect of the heating supply. Thus we must implement the reform of the heating system and charge the heating fee according to the users' consumption. For adapting to the reform, the heating system should be installed relative metering and control instruments to supply heat according to the need.When the adjustment instruments such as thermostatic valves are installed, the consumers become the host of the heating system. The variable flow heating system is quite different from the constant flow heating system. So the relative control strategy for the heating network should be changed.In the beginning, the need of the consumers for the heat is discussed in this thesis. Two factors influence the need of the heat. One is artificial the other is not artificial. The heating network is divided into several arrangements: the typical house model, the typical building model, the typical secondary netnetwork model, the heating station model and the heating network model. For the house model, there are 12 house models and 3 consumer models in this thesis. By the combination of the house model and the consumer model, there are different needs of the radiator heat and water. According to the different scale of the 3 consumer models, the building model and the secondary network model are separated into 5 kinds. Then the sum of the 5 kinds of the building models and secondary network models can be calculated. With the model of the heat exchanger, the flow of the heating networks will be got. According to the variation of the flow, the branch network with a single heat production plant is simulated and a new method that can find the pressure-difference reference point of the network is discussed. The pressure difference at the reference point should be a variable value is also put forward in this thesis. Because of the consumers' needs vary from hour to hour, a new method is put forward that can forecast the consumers' need according to the colligation weather temperature of the current hour and the former hours. Then the relationship of the heat variation and the water flux of the network are discussed. So from the heat we forecast, the need of the flux are known and the need of the pressure difference is got.Some tests were carried out in Beijing and Tianjin by the author. The results of the tests validate that the variation of the variable flow system is most influenced by the weather temperature and the solar radiation. The adjustment of the people also influences the variation of the flux in some degree.