The Analysis Of Hydraulic Condition In Indoor Hot Water Heat-Supply System

Because of demand in energy saving on heating and the transition from planned economy to market economy, it is imperative of supply heat industry to change the charge on area into charge on actual heat consumption in China in recent years. The prerequisite of implementing charge on heat consumption is interior heat-supply can be individual metered and controlled. It is needed to remould amounts of the traditional indoor upside feed and underside return flow and single pipe downflow system.This paper induces kinds of existing building heating system renovation form, analyzes characteristic of different forms and reaches the application range of each renovation form. It can be concluded that vertical single-pipe cross-over heating system is with best performance based on the analysis and comparison for existing building heating system renovation.The paper presents the simulation calculation and analysis of the vertical single-pipe cross-over heating system. By simulative calculating the change of flux and heating load after reforming of heating system, it gives out the choice of initial state after the system is reconstructed. The flux of radiator decreases so that reduces heating load more or less after the reconstruction. This problem can be solved by increasing number of radiator slices or increasing supply water temperature. Meanwhile, the change condition of system is also simulative calculated after reform when it uses constant pressure and constant flow to control in heat entrance. It is concluded that the constant pressure control is the most suitable for the vertical single-pipe cross-over heating system.The calculation method of network graph theory is used to solve the impedance of combined pipe in reversed return system and the Visual C++ Language is also used for programming. The simulating results of system flux after transformation are close to direct return system. From above researches, the correlative conclusions are significant for practical household rebuilding project to the existing building heating system.