THERMODYNAMIC IMPERATIVES THE MODERNIZATION OF THE ELECTRIC DRIVE OF PUMP UNITS OF THE CENTRALIZED HEAT SUPPLY NETWORK IN THE CONTEXT OF INCREASEING ENERGY EFFICIENCY

Abstract

The relationship between thermodynamic and hydraulic parameters of the heat supply network has been established. The dependence of the electric power consumed by the electric drive of the pump unit on the pressure and supply of the coolant was determined. It is proved that the regulated electric drive system has advantages over the non-regulated electric drive system in the context of energy efficiency of the pumping unit and the district heating network in general. Approaches and criteria for the synthesis of a regulated electric drive system, including its automatic control system, were determined, regulation methods were analyzed, and the most acceptable version of the electric drive was chosen: a controlled frequency converter - an asynchronous motor with a short-circuited rotor, taking into account the above, an energy-saving mechanical system of a centralized heat supply network was synthesized. The peculiarity of this system is that the protection of parameters of hydraulic and temperature regimes in the network of centralized heat supply is ensured with the help of extreme automatic control systems. At the same time, the assignment of mode parameters is provided by the temperature controller of the heat exchange point of the network. Regulation of the pressure and productivity of the pumping unit is carried out by changing, according to a certain law, the frequency and power supply of the asynchronous motor.