Optimal Control Of Thermal Balance Of Heating Network

The central heating system with high efficiency and high degree of automation is the long-term pursuit of urban central heating system.With the development of heating system towards urban central heating and cogeneration of heat and power,the traditional heating pipe network system is faced with various development bottlenecks.It is an inevitable choice to design the corresponding control system of heating pipe network to optimize the heating system.This paper takes the heat exchange station with indirect connection of heating system and heating system with secondary pipe network as the research object and combines the problem of thermal balance that needs to be solved in practice.The research,analysis and design are carried out from four aspects.First,the heat distribution scheme of the primary pipe network of the heat exchange station is optimized,with the room temperature as the target value and the frequency converter and electric control valve as the implementation link to achieve the balanced distribution of heat to the primary pipe network.Using the method of square wave response of a set of heat exchange unit,mathematical modeling,the entrance with a water inlet side heating pipelines or electric control valve opening for the input,the outlet water temperature of providing heat through pipes in secondary side output,established the mathematical model of heat exchanger station,and use the PID control method,through the critical proportion method for PID parameter setting.Secondly,the thermodynamic equilibrium strategy was optimized,and the mathematical relationship between the outdoor temperature,indoor temperature,primary inlet temperature,secondary outlet temperature and other data was found through numerical analysis and data fitting.Combined with the relation between different temperatures and the mathematical model of heat exchange station,a thermodynamic equilibrium optimization scheme for heating network is proposed.Third,optimize the heating pipe network system,designed a at room temperature for direct reference temperature,and the remote wireless transmission signal of the secondary side of heating pipe network control system,the subsystem of indoor temperature as feedback values directly feedback to the control center,can effectively reduce the indoor space,indoor and ventilated environment different,such as building insulation different interference factor’s influence on the heating system.Fourth,to control the heating network system has been optimized,fan pump frequency converter as the control center,circulating pump,water pump for execution link,position type PID control algorithm to control the circulating pump,the use of electric contact pressure gauge and many sections of control method to control pump,effectively reduce the heat load calculation error,to ensure the system security,stability and high efficiency of the equipment operation.