Research And Application Of The Central Heating System For "Small Boiler Grid Connection"

In recent years,in order to alleviate and manage the problem of the environment,the whole country has begun to vigorously rectify the heating of small boilers and vigorously promote centralized heating.The country is paying more and more attention to environmental protection and energy conservation and emission reduction.It has also introduced a number of policies and regulations on heating.It is inevitable that the small and medium-sized boiler houses with dispersed coal will be replaced by cogeneration.At present,many heating and self-supply units are considering how to incorporate a small heating system into the municipal central heating network.This paper first proposes the transformation schemes that may be used in various engineering projects for small boilers,and finds out the characteristics and influencing factors of various schemes and enumerates them one by one.The two main factors that need to be considered in the selection of small boilers before grid connection are the heat supply capacity of the heat source and the location of the new heating system.For the grid-connected system,the burden of the original heating trunk line will be greatly increased.If the system does not change,the current pipe network will be too small,resulting in a large pipe network resistance.The pump provided by the original heating system is not enough to provide the power of the entire pipe network.Based on this,three reforming schemes are proposed.That is,the relay pump station scheme,the distributed variable frequency pump scheme and the bypass water mixing scheme are added.Secondly,the mathematical model of hydraulic conditions for centralized heating branch pipe network is expounded,which lays a foundation for the study of hydraulic calculation and reconstruction scheme of heat pipe network for small boilers.In addition,the authors determined the optimization objectives and established an economic model for each program based on the possible transformation plan.The economic model of this paper considers the use time factor of the equipment and adopts the dynamic analysis method: the cost annual value method.Finally,according to the actual engineering case,the theoretical research results of this paper are verified.Finally,the initial investment of the relay pumping station reconstruction plan is 103.865 million yuan,and the initial investment of the distributed variable frequency pump reforming plan is 6.174431 million yuan.The initialinvestment in the station reconstruction plan was 41.419 million yuan more than the initial investment in the distributed inverter pump retrofit program.In this project,from the initial investment point of view,the distributed variable frequency pump retrofit solution has obvious advantages.The research results of this paper provide a certain theoretical basis and decision-making basis for practical engineering.Through the comparison and selection of practical engineering cases,the reference to other similar practical projects is provided.