Application And Research Of Central Heating System Based On Jet Pump Technology

Nowadays,the central heating system generally has the imbalance of hydraulic and thermal in our country,and cause thermal users to have serious heating phenomenon: uneven cold and hot,near hot and far cold.The traditional operation modes of "large flow and small temperature difference" in both the primary and secondary networks have not only greatly increased the power consumption of the circulating pump,but also the current situation of high energy consumption and hydraulic imbalance in the heating network remains unresolved.In order to reduce heating energy consumption,eliminate hydraulic imbalance,and improve the heating quality of users,the aim of this paper is to apply jet pump to thermal entrance of secondary network,make full use of rich pressure of pipe network to achieve mixed water heating,and improve the hydraulic stability of the system,reduce the flow of trunk distribution and achieve the purpose of energy-saving and emission-reduction.Based on the basic design theory of jet pump,combined with the heating conditions and performance requirements of the actual project,one jet pump structure and key size parameters applied to the secondary thermal entrance are optimized design.In order to verify the rationality of the design of the jet pump,a prototype experiment is performed to analyze the change regulation of jet pump characteristic curve when the heating condition of network changes.The aim is to meet normal operation of jet pump in an efficient working area and improve the performance characteristics and operation effects of jet pump heating system when heat-supply network is operating under variable conditions.The effects of working fluid pressure,ejection fluid pressure,and outlet fluid pressure on the performance characteristics and mixed water characteristics of jet pump are analyzed experimentally in order to optimize operation regulation and obtain the reasonable value of outlet pressure of jet pump.Finally,we take an actual project as example to compare and analyze energy saving,economy and comfort of jet pump heating system in Beijing residential district heating network.