Study On The Operational Adjusting Characteristics Of Large-scale Heating Network Which Based On Cogeneration System

In the heating system which based on combined heat and power as heat source,the first heat exchange station cannot be as the outdoor temperature and the hourly regulation accordingly in order to guarantee the cogeneration unit can run smoothly.However,with various large heating system began to take energy saving reconstruction," Intelligent Heating System Based on Heat-metering" can be independently regulate with the change of heat load.As a result,the pipeline for heating system pressure will fluctuate violently,and more than likely to happen such obvious problems as pipes burst.Urgently needed to be solved for the above problems,this topic is related research mainly about the reliability renovation of the above type of heating system impacts on the heat-supply operation adjustment feature.First of all,based on the knowledge of network graph theory and fluid mechanics to establish the mathematical simulation model of central heating system.Combined with a certain area in Hebei province based on the large-scale central heat supply system reliability of cogeneration transformation of real example,carried out simulation research work which based on the reliability of large cogeneration heating system before and after operation adjustment feature.At last,according to the experience of the practical operation of the heating season effect for the modification of the heating network system reliability analysis.Considering the actual design parameters and the complexity of pipe network,we use the thermal fluid flow simulation software to build a large heating pipe network model which is based on cogeneration.According to the simulation about different location on the network of the modification of the by-pass pipe heat exchanger station,concluded that the most advantageous position is the heating system front-end heat transfer station.The analyses the characteristics of the simulated network operational adjustment: Based on the actual network retrofit scheme and the dynamic simulation of entire network can be concluded that the retrofit by-pass pipe not only realizes the decoupling of the “source-network” adjustment target,and the heat transfer quantity of the first heat exchange station saving rate up to 8.6%.Using the simulation software to simulate and provids bypass the bypass within the heat exchange station integrated differential pressure control effect of,main draw bypass pressure difference control more independent and efficient.The heating season provids bypass overpressure alarm prompt number has reached more than 10 times.According to the actual pipe network transformation,network operation is given proposal.If the each heat exchanger station of network adopt automatic contro energy saving is more than 5% in the largescale central heat supply system of the whole season.As the heating system local autonomous regulation strategy is more and more mature,large-scale central heat supply network stability and reliability of the heating pipe network transformation is imminent.The research that the decoupling of the “source-network” adjustment presents a new direction in the large central heating pipe network on security and reliability of transformation.