Dynamic Analysis And Control Strategy Of Acentral Heating System Based On Actual Measurement In Xi'an

In the winter,there is enormous energy consumption of heating and creating serious smog in China.Therefore,it is crucial to reduce the energy consumption and improve the efficiency of the energy.In this article,the thermal load of one residential architecture was simulated,and,in the same time,the heating operation condition was measured practically in Xi'an.The reasonable operation and heating regulation are proved for heat station by comparing and analyzing the heat source center.DeST software is used to simulate to calculate the thermal load by build the model of the real architecture.The change of the sickness of the insulation layer,the type of the external windows,the ratio of window to wall and the orientation of the building as the factors and simulating the thermal load and the contribution to the internal natural temperature.According to the simulation output,there are three conclusions by analyzing the data.Firstly,residential buildings in Xi'an utilize the walls of the low heat transfer coefficient with taking the economic insulation thickness.Secondly,there is intense coupling between the performance of insulation in the window and the ratio of window because of the coupling factors.The insulation efficient of the window contributes more than the ratio of window in building energy consumption.The last one is a fact that the best designing orientation of the residential buildings in Xi'an is South West 15°only considering the heating load.Simulating the theorical demanding heat,the heating system taking the non-property adjusting measure leads to the over-heating in the building.To confirm the correctness of this conclusion with the weather parameter of heating in Xi'an,the internal temperature in this residential building and the relationship between the supply and return temperature and flux data in the secondary network were researched.The conclusion is that the unbalanced factor in one building,the difference among several buildings,the adjusting measure in irrelevant time and overestimating heating with high internal temperature are caused by improper managing measure.It will make the phenomenon that the over high temperature indoor happens in part of rooms or the whole space.The central heating network,the thermal loss in network and electric consumption were analyzed specifically.The cascade technology of reducing return water temperature was proved.To be more clear,the economic consumption was tested in actual project,after taking the new technology this project saved electric energy 68179045KW·h.The old system will cut down 8.1815 million RMB every year if the price of industry electric fee is 1.2RMB/KW·h.This technology save 23915m3 natural gas or 55.0052 million RMB every year in the price of the industry gas 2.3 RMB/m3.The heat load of simulation and tested were researched by compared in this residential building,and 75/50? regular designing calculation method was changed.Based on heat net supply water and return water temperature in the tested internal temperature about 20?,the qualitative regulation,the qualitive regulation of changing flow staged,the quality-flow regulation,the feedforward dynamic regulation and the heat regulation were studied in this building.In these five conditions,the booster pump power consumption and the heat gas consumption were calculated,compared with the consumption of gas and electric in qualitive regulation.The ratio of saving gas in the qualitive regulation of changing flow staged is 2.07% and the consumption electric energy reduces 18.34%.By using quality-flow regulation,it saves20.61% natural gas and 10.72% electric power.However,this regulation is proved to suit for the area where has automatic control facilities and the temperature is more than-3? outdoors in the heating season.The ratio of saving gas arrives 20.38% and the method of heat regulation is able to forecast the consumption of gas energy when the large or middle heat source at full load in low efficiency.What deserves to be mentioned the most is the hydraulic regime more stable than quality-flow adjustment.The feedforward dynamic regulation cuts down 26.6%natural gas energy than qualitative regulation and focus the time when the temperature is in wave crest and valley time temperature indoors.The hydraulic regime of network and indoor temperature maintenance stable,and,improving the quality of residential environment with saving energy comes true.