The Research Of Distributed Variable-frequency Heating System In Handan Development Zone

With the acceleration of urbanization in China,the scale of central heating system is becoming larger and larger.Most of the heating systems are designed according to the traditional centralized power transmission and distribution system.Such a system is easy to form the near end thermal user throttling loss is serious,far end hot user's capital pressure head is insufficient,the operation adjustment effect is poor,the heating quality is low and the energy consumption waste serious phenomenon.For the above problems,some scholars proposed distributed frequency conversion system.Distributed frequency conversion system has the advantages of low energy consumption,high system stability and good control ability.With the development of frequency conversion technology and the production process of water pump in recent years,the distributed variable frequency heating system has become a hot topic in today's research.This paper mainly focuses on the power distributed heating system of variable frequency pump namely the distributed frequency conversion heating system for analysis and research.Firstly,the research significance of distributed frequency conversion pipeline network is given based on the study of distributed variable frequency pump by many scholars in China and abroad.The existing problems in central heating system in China are analyzed,and the necessity of the research of distributed variable frequency distribution system is obtained.Then,this paper expounds the basic principle and advantages of distributed frequency conversion system,determination of heat load calculation and hydraulic calculation,Hydraulic misalignment,causes and adjustment methods of hydraulic imbalance.Then the principle of variable frequency regulation of water pump and the energy saving analysis of the variable frequency pump are analyzed.Secondly,combined with practical engineering,the general situation of Handan development zone is introduced,this paper analyzes the heating load and its thermal load calculation,and draw the annual heating load delay curve diagram,calculated the outdoor temperature and the annual heating load.The hydraulic calculation is analyzed and the water pressure diagram is drawn,finally,the existing problems of the project are put forward,one of the solutions to these problems is using distributed frequency conversion heating to design a distributed variable frequency heating system scheme.Thirdly,by designing the scheme of distributed variable frequency heating system,the schematic diagram of the system is given,the system control scheme is proposed.The system control scheme is introduced from the selection of differential pressure control point,the hydraulic control of the distributed frequency conversion system,the selection of the primary backwater pump,the control of the user pressure pump and the control of the main circulating pump of the heat source.Finally,the characteristics of distributed system are summarized.In the end,comparing the design of the traditional design and distributed frequency conversion system.Through the selection of the traditional scheme and the estimation of investment,through the selection of equipment and investment estimation of the distributed variable frequency pump system,carry out the economic benefit analysis of both.Using the annual cost method in engineering economics to calculate the economic index of the project after the transformation,the static recovery period is calculated for the initial investment of the newly added variable frequency pump,then combined economic analysis to select optimal scheme.At last,environmental review and energy conservation analysis are conducted.Which come to a conclusion that distributed variable frequency network system will play a positive role in the economic development,urban construction and urban environment improvement of handan city and its surrounding areas,it can also have beneficial effects on protecting the environment and saving energy.