Pressure transmitter in the application of heat exchanger station intelligent control system

With the development of economy, the call for a nationwide environmental protection, energy saving more and more high, the use of advanced science and technology, the reasonable distribution of heat, to give full play to the role of the existing heat, to serve more users to provide better heating is the primary task of heat-supply enterprise. To the introduction of the microcomputer monitoring and automatic control in the heating system, to adjust the heating system make the transition from manual to automatic, it can meet the demand of heating under the new situation. Heat exchanger station an overview of the heat exchanger station mainly through the heat exchanger equipment will generate a high electric field with warm water and user secondary network are closed by the low temperature water to heat exchange, and then through the circulating pump equipment to overcome the resistance of the secondary network formation, the final will be transferred to the indoor hot water in the radiator. Control purpose and main controlled equipment heat exchanger station system control purpose: through the circulating pump, water pump, heat exchanger, temperature control valve, regulator to control the system pipeline, adjust the mode of the system working condition of each application, in the economic case for the terminal to provide a stable water supply temperature. At the same time, improve the automation level of the system, improve the management efficiency and reduce labor intensity of the system. Control cabinet to the acquisition of pressure and temperature of the pipe and then to the control of circulating pump, pump, to control the temperature control valve, water level, etc. （ 1) According to the control of equipment operation process and electrical components, arrange PLC interface, write I/O address allocation table. （ 2) Communicate with PLCCOM1 mouth touch screen, playing board through PLCCOM2 mouth to communicate. （ 3) The program design. Process: (1) control of PLC on electrical after the operation, first of all, the program is initialized, set by the touch screen for secondary side water pressure, temperature, a lateral water pressure temperature, heat exchanger, water temperature and overtemperature control parameters such as temperature. After the automatic position, start control. Cycle scan and PID control program, carries out numerical samples such as pressure, temperature, respectively through the internal operation process, compared with the set value, according to the results of PID adjustment, calculates the numerical values given switch and analog signals, and control water pump start-up and frequency adjustment. (2) programmable programming: automatic control system by PLC, inverter, pressure transmitter, temperature transmitter, liquid level transmitter and other major electrical components. Pump by water pressure control start-stop; Circulation pump frequency conversion, frequency by for back pressure difference to adjust; Condensate pump through the cooling water tank water level operation. Recycle water pump control principle: by means of pressure transmitter to transfer current signal to PLC, through the PLC operation, compare to the set value, feedback value when the pressure to set the lower limit value, the PLC signal is given automatically start pump; When the pressure to set the upper limit, the PLC signal is given automatically stop the pump; And filling water tank water level below the protection value, the pump pump forced shutdown. Circulating pump control principle: by backwater pressure transmitter and water supply pressure transmitter to transfer current signal to PLC respectively, through the PLC operation, feedback for return water pressure difference and setting of pressure difference, when below the set value, the PLC output voltage signal to frequency converter, linear increasing circulation pump frequency, speed accelerated; When higher than the set value, PLC in the same output voltage signal to frequency converter, circulation pump frequency linear regressive, speed; When close to the set value, circulating pump constant speed operation. Magnetic flap of condensate pump control principle: the cooling water tank level gauge will be transmitted current signal to the PLC, through the PLC operation, compare to the set value, feedback value when the tank water level to set the upper limit, the PLC signal is given automatically start the cooling pump instructions; When the water level to set the lower limit value, the PLC instruction signal automatically stop the cooling pump is given.