Automation diagram "KVGM-100 boiler on gas"

Automatic control of the boiler operation takes place in five main branches (load control, economy, smoke pump thrust, hot water temperature, feed water pressure) and seven auxiliary branches, ensuring safety, stability, and efficiency of the boiler operation. The load is controlled by a microprocessor 1-10 which provides a signal to the magnetic valve starters to control the flow of fuel 1-6 and air 1-7 based on the temperature sensors of the heated water in the boiler 1-1 and its flow 1-3. Accordingly, as the temperature and/or water flow rate decreases, the amount of fuel-air mixture entering the furnace is controlled. When the permissible temperature is exceeded, an alarm lamp is activated to alert operators and prevent an emergency. Control of economy is performed by regulator 2-3 on the basis of readings of fuel flow sensor 2-1. Regulator supplies signal of opening or closing of air supply valve 1-7 by means of magnetic starter 1-8. The purpose of the regulator is to maintain the most economical fuel-air mixture. Thrust control is performed by 3-6 regulator on the basis of vacuum meter readings 3-1. The signal from the regulator is transmitted to the frequency regulator of the smoke pump 3-3, changing its rotation frequency. This automation branch shall continuously provide gas discharge in the furnace in order to avoid flue gases breaking into the shop room. The temperature of hot water at the boiler outlet must always correspond to the specified one, regardless of the load, for this there is a boiler water circulation line with a valve 4-1 installed on it and a temperature sensor 4-3. The controller 4-5 sends a signal to the magnetic converter 4-2 to close the valve and, accordingly, in reverse order when the temperature deviates upwards. The feed control is to maintain the feed water pressure at the boiler inlet. The regulator 5-5, receiving data from the pressure sensor 5-3, controls the magnetic starter 5-2 to close or open the valve 5-1, which provides a water pressure boost after the feed pump. In addition to the main branches of automation, branches of information display and recording, signals about deviations in indicators are also important. Pressure gauges (6-1 and 7-1, respectively) are installed to supply fuel oil and air, transmitting readings to the board, and signalling lamps to prevent malfunctioning of the main boiler automation lines, or their diagnostics. For example, with a sharp increase in air pressure, the flame in the furnace may fade. Pressure gauges are also installed in front of feed pump 9-1 and at hot water outlet from boiler 8-1. Their main functions are warning of personnel about deviations, possibly actuation of protective shutoff devices. To monitor the operation of the boiler, calculate the actual efficiency, feedwater temperature sensors 10-1 (before the pump), flue gases 11-1 are installed. A flame temperature (color) sensor 12-1 is also provided in the boiler furnace, which is used to monitor the combustion process.