Technical Economic Research On Heat Exchange Station Distribution Pattern

Large group substation is popular in district heating in China. The actual operation of hydraulic imbalance, thermal imbalance, high pump power consumption is getting more and more serious. Most of the heating system remains constant flow regulation, which is not conducive to heat metering, heating goods reform. Compared with European building substation and automatic variable flow heating system, which is essential for on-demand heating, heat metering and behavior energy-saving, the Chinese government launched a building substation heat exchange and metering demonstration project, attampting to explore a reform path to heating system modernlization under Chinese context.Dealing with the economic and technological dispute for the application of building substation in China district heating system, based on a heating region, this paper carries out a comparative study of economic and technical analysis on building substation and group substation heating system, attempting to explore the reasonable application situation of heat exchange station distribution patterns.Firstly, based on a certain virtual heating area, assuming even distribution of heating load and buildings in the region, typical grid models are established. The annual cost method is chosen to conduct heating economic and technical analysis, and the comparative study process is determined. The project initial investment, operating costs, energy consumption composition are analyzed. Conclusions can be drawn that the heating network investment and heat exchange station investment have a greater influence on comparison results. Building station heating system can significantly reduce the consumption of water and electricity. These jobs make preparation for the following impact factors analysis.Secondly, influencing factors for heat exchange station distribution patterns, assuming uniform heat load distribution, are analyzed. Factors include heat load density, heating network initial investment, building station investment, group station investment. The analysis of heat load density includes three aspects, namely(1) the total heating area,(2) equivalent heating radius,(3) intergration effect of heating area and equivalent heating radius. It is suitable for building station application with single building of large heating area, small heating radius and high load density. Compared with group station heating system, annual cost of building station heating system presents greater volatility in net investment. The heat station investment has a greater impact on annual cost for building station compared with group station. Using variable dimensionless approach to deal with economic factors, a comprehensive comparison is conducted. The results show that the total heating area and building station initial investment charges a strong impact on the comparative study.Then, this paper analyzes the influence of load distribution uniformity on the heat exchange station distribution pattern. Non-uniform load distribution condition is studied considering buildings in the heating area with random array of volume rate. Load power moment method is introduced to depcit load distribution and to obtain load centers in non-uniform distribution. The polar distance between load center and group substation are calculated. Compared to the results of uniformly distributed load under the same conditions, investments of building station heating system has a larger fluctuation than group station heating system with the changes of load distribution; impact of load uniformity on operating costs and annual cost between building substation and group substation depends on grid mesh.Finally, based on the ideal mesh, techno-economic impact of architectural vertical zones, forms of heating, and load density on the heat exchange station distribution pattern is analyzed. There is no strict decline of fees and cost relative percentage with the load density increasing, when the building crossing different vertical zones. With a certain building zone and heating form, the greater the load density, the fewer the unit initial investment, unit operating costs, annual cost and corresponding percentage differences. In another words, building station heating system becomes more economic with increasing load density.