Gas-fired boiler control system

Abstract

The invention discloses a gas-fired boiler control system. The gas-fired boiler control system includes a boiler body, a first PID controller, a flue gas oxygen content inspection module, a gas flow inspection module, a signal conversion module, a frequency changer and a draught fan. The boiler body is provided with a valve, the signal conversion module is electrically connected with the gas flowinspection module, the flue gas oxygen content inspection module corresponds to the boiler body, the first PID controller is electrically connected with the flue gas oxygen content inspection module,the first PID controller is electrically connected with the frequency changer, the frequency changer is electrically connected with the signal conversion module, and the draught fan is connected withthe frequency changer. The oxygen content of flue gas emission of the boiler body is inspected in real time through the flue gas oxygen inspection module, the frequency changer is controlled by the first PID controller though the corresponding signals of the flue gas oxygen content, and the rotary speed of the draught fan is changed; and boiler gas flow signals are obtained through the gas flow inspection module, the flow signals are converted to input control signals of the frequency changer through the signal conversion module, thus frequency conversion of the frequency changer is achieved,the rotary speed of the draught fan is changed, and thus the air volume of the boiler can be adjusted.

Description

technical field [0001] The invention belongs to an important part of a gas boiler, in particular to a gas boiler control system. Background technique [0002] For a long time, industrial boilers have been widely used in manufacturing industries, and coal has always been the combustion fuel of industrial boilers. During transportation, storage and combustion, coal dust causes serious environmental pollution. At the same time, coal-fired boilers have a lot of heat loss, produce a large amount of harmful gases such as carbon dioxide and sulfur dioxide, and have a high excess air coefficient, which makes it difficult to realize automatic control and adjustment, effectively saving energy. [0003] In order to strengthen the prevention and control of air pollution, optimize the energy structure, and effectively increase the utilization rate of clean energy, the country vigorously promotes "coal to gas", which makes industrial gas-fired boilers widely used in heating and industria...

AI Technical Summary

Problems solved by technology

In these two control methods, due to the nonlinear relationship between the damper damper opening and the load, it is difficult to achieve accurate control of the damper damper opening and the actual amount of air entering the furnace.

The air intake volume of the existing boiler is based on the gas flow signal, and the opening of the damper baffle is directly controlled by the valve opening connecting rod to control the actual air volume entering the boiler. Since the opening control of the connecting rod and the damper is mechanically operated, this control method Large error, low adjustment accuracy

In addition, even if the frequency converter is added to improve the accuracy of air volume adjustment, due to the change of working conditions, the temperature of the surrounding air or hot air is different, the combustion status of the boiler cannot reach the best state, and economical combustion cannot be achieved.

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