Study On The Combined Heat And Power Operation Considering Difference In Heat Demand Characteristics Of Building

In recent years,the wind power industry of China has developed rapidly,especially inthe "Three North" area of China which has rich wind resources,and the development of wind power is very rapid.However,in the "Three North" area,the central heating is implemented and the heating period is long,and the high proportion of the combined heat and power(CHP)units not only ensure heating demand of people's livelihood,but also occupy the large power generation space by their forced output,which results in serious wind abandonment.Considering the thermal dynamic characteristics of the central heating system,the combined heat and power operation is an effective way to alleviate this kind of wind abandonment problem,which is of great significance to improve the operation flexibility of the CHP units and the wind power consumption capability of the system.Based on the thermal dynamic characteristics of the central heating system including buildings,this paper studies combined heat and power operation considering difference in heat demand characteristics of building.Based on the summary of the basic modeling of the key links of the central heating system running in the mode of quality contro,this paper analyzes the heat demand characteristics of public buildings and residential buildings,and the corresponding centralized control with flow varied by steps mode for heat system,and expounds the basic idea of combined and heat operation considering difference in heat demand characteristics of building.Then,the central heating system under the centralized control with flow varied by steps mode after considering the difference of building heat demand is analyzed and modeled.The paper focuses on the analysis of the hydraulic condition of the heating network and the operation control mode of the frequency converter which supports the stability of the hydraulic condition of the heating network.The paper also models the heating pipeline with different flow rates and the heat demand characteristics of different buildings.Finally,aiming at the minimization of the combined heat and operation cost including the penalty cost of wind abandonment,considering the constraints of heat system and power system,the combined heat and power operation model considering difference in heat demand characteristics of building is constructed.The effectiveness of the model in reducing the operation cost of the system and eliminating wind abandonment is verified by simulation examples.The results of the examples show that the combined heat andpower operation considering the thermal dynamic characteristics of the heat system can leave more space for the wind power;based on the thermal dynamic characteristics of the heat system and the further consideration of the differences in the heat demand of the buildings,the combined heat and power operation will have better economy and more obvious advantages in the windy and extremely cold weather conditions;when the public buildings are adjusted in a reasonable centralized control with flow varied by steps mode,the thermal dynamic characteristics and heat demand characteristics of the system can be brought into full play,and the wind power consumption can be promoted at the same time of the economic operation of the system.The research on combined heat and power operation considering difference in heat demand characteristics of building in this paper can provide a reference for the further absorption of abandoned wind in China.