Key words: automatic control technology; Central heating; System design; Design principles; application

3503E In winter, due to the low temperature in the north of our country, heating energy consumption is large, and more serious energy shortage situation. Good results have been achieved by adopting automatic control system to energy saving in the current residential district heating system structure. With the continuous progress of Chinese technology and economic development, automatic control technology is applied to the energy saving of central heating, and a certain effect has been achieved. However, in the last few years, the results of the application of automatic control technology in central heating energy saving are not ideal. There are some problems. At this point, some suggestions are put forward for the application of automatic control technology in energy saving of central heating.

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1. Design principles of automatic control system of heat exchange station

3503E In order to reduce economic cost and water and electricity consumption on the basis of ensuring heating quality, a scientific and reasonable automatic control system is put forward. According to the complexity and scale of heating system, high cost performance automatic control system equipment is used. The use of heat network RTU system during the use of Schneider brand PLC. The automatic system of heat exchange station needs to develop targeted control strategies because of the different heating forms and unit equipment. Reliability, simplicity, practicability and maintainability should be considered in the selection of control system and supporting instrument. In the process of automatic control system design, the compatibility, openness, stability, universality and expansibility of the whole system should be fully taken into account.

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B. The composition of automatic control system of heat exchange station

3503E Our company’s form of heating is through the heat exchanger for the central heating – secondary network and the user’s secondary network for heat exchange, through the secondary network to transfer the heat to the user. The RUT system of the heat exchange station is composed of PLC, phenomenon instrument, communication interface, man-machine interface touch screen, etc. Through flow, temperature, pressure and other parameters, the field instrument sensor is converted into a standard current signal, the inverter will motor current, speed and other signals into the PLC, through the PLC control frequency converter start and stop and speed regulation. As the man-machine interface of the phenomenon, the touch screen displays the main parameters and equipment status of the heat exchange station, and the field command operation can also be sent through the touch screen

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3. Heating control strategy of heat exchange station

3503E When the hot water network operates in a stable state, without considering the loss of the network management along the way, the heat supply of the network should be equal to the heat lost by the heating user to the heating equipment, and also equal to the heat load of the heating user, which is called heat balance.