Research On Feedforward Dynamic Adjust Method Of Heating Supply Network Based On Comprehensive Meteorological Prediction

At present, majority of heating company choose "steady heating combined with climate compensation" as operation and regulation strategy, even some heating company still has no climate compensation equipment. The strategy of "steady heating combined with climate compensation" ignores the influence of other meteorological parameters (e.g. solar radiation, wind) on the indoor air temperature, which make the supply heating does not match heat load on quantity. Meanwhile, because of the lag time of heating and thermal inertia of building envelope, feedback regulation also causes supply heating does not match heat load on time. Here are two consequences. One is indoor air temperature fluctuate obviously, and the other is make no use of solar radiation. Especially, with the energy efficiency standards more strict, influences of other meteorological parameters become more important.Contrary to steady load calculation method according to design comprehensive performance, this paper established the Double-S model for the dynamic load calculation method according to actual time-lag comprehensive performance. Then, the Comprehensive Time-weight Outdoor Temperature model was proposed. Combined with the simplified model of heat supply system dynamic performance model, this paper established a new Feedforward Dynamic Adjust Method. The method owns high validity and accuracy according to the experiment result. This paper also discussed the scope of the new method. The new method can improve indoor thermal comfort and save heating consumption with a certain thermal comfort.Firstly, based on the analysis of mathematical model of "steady heating combined with climate compensation", established Double-S model which is used for dynamic adjust method. This paper discussed how different meteorological parameters influence the indoor air temperature through different building envelopes which means that different parameters own different lag time. As the outdoor temperature is the most important parameter for the heating and the unique parameter which the climate compensator according to, the paper makes other meteorological parameters’influence on the indoor air temperature equivalent to the change of outdoor temperature.That is to say, the solar radiation equates the outdoor temperature rise and the wind equates the outdoor temperature fall. The Comprehensive time-weight outdoor temperature model has been established and all the meteorological parameters in the model are related to time and different buildings envelope.Secondly, the heat supply system dynamic performance model was established using harmonic analysis method. Two most important thermal dynamic characteristic parameters lag time and decay coefficient, for heat supply system has been proposed. This paper also proposed simplified model for the application of engineering. The model owns high accuracy according to the operation data. It has been conclusion that the lag time of the heating supply system is nearly equal to the flow time in the pipe.Then, this paper proposed a new adjust method for heating system operation, which is named "Feedforward Dynamic Adjust Method of Heating Supply Network Based on Comprehensive Meteorological Prediction". The dynamic model for calculating the hourly heat load has been established. Take the quality regulation and radiators as the example; the formula of hourly heating supply target temperature has been given.Choose an actual heat station in Beijing as the experiment environment, the validation of the new model has been practiced. The operation data of the heating system in the last heating season has been monitoring. The accuracy of two models, Comprehensive Time-weight Outdoor Temperature model, Feedforward Dynamic Adjust Method of Heating Supply Network Based on Comprehensive Meteorological Prediction model, has been verified. The regulation effect of the new model has been compared with other three regulation methods, climate compensation method, constant heat supply temperature method, and timely regulation method. The conclusion can be got that the new method can improve indoor thermal comfort and save heating consumption with a certain thermal comfort.Based on the analysis of the model applied to 39 cities in north China, the scope of the model has been proposed. The result shows ideal effect.