KR-102964946-B1 - Combustion equipment

KR102964946B1KR 102964946 B1KR102964946 B1KR 102964946B1KR-102964946-B1

Abstract

When the ratio of fuel gas (G) supplied to the burner (20) and combustion air (Air) is adjusted by the air ratio control system (50) to combust the fuel gas and combustion air in the furnace (10), the oxygen concentration inside the furnace detected by the oxygen concentration sensor (51) is output to the air ratio control system by the output control device (52) and the ratio of fuel gas supplied to the burner and combustion air is adjusted. However, if the oxygen concentration inside the furnace detected by the oxygen concentration sensor changes significantly, the detected oxygen concentration inside the furnace is not output to the air ratio control system by the output control device, and the ratio of fuel gas supplied to the burner and combustion air is maintained by the air ratio control system.

Inventors

사쿠베야 고지
가타야마 도모키

Assignees

쥬가이로 고교 가부시키가이샤

Dates

Publication Date: 20260513
Application Date: 20230613
Priority Date: 20220829

Claims (2)

In a combustion facility that adjusts the ratio of fuel supplied through a fuel supply pipe to combustion air supplied through an air supply pipe using an air-ratio control system and supplies it to a burner, and injects the fuel and combustion air from the burner into a furnace for combustion, an oxygen concentration sensor is installed to detect the oxygen concentration inside the furnace, and the oxygen concentration inside the furnace detected by the oxygen concentration sensor is output to the air-ratio control system by an output control device, thereby adjusting the ratio of fuel and combustion air supplied to the burner by the air-ratio control system; however, when a door installed in the furnace is opened, causing the amount of incoming air entering the furnace to increase and the oxygen concentration inside the furnace detected by the oxygen concentration sensor to increase significantly, the oxygen concentration inside the furnace detected by the oxygen concentration sensor is not output to the air-ratio control system by the output control device, and the ratio of fuel and combustion air supplied to the burner is maintained by the air-ratio control system; whereas, when the door is closed and the oxygen concentration inside the furnace detected by the oxygen concentration sensor returns to a predetermined value, the oxygen inside the furnace detected by the oxygen concentration sensor A combustion facility characterized by outputting a concentration to the air-ratio control system by means of the output control device, and controlling the ratio of fuel supplied to the burner to combustion air by means of the air-ratio control system.
In the description of claim 1, A combustion facility characterized by setting the timing for not outputting the oxygen concentration inside the furnace detected by the oxygen concentration sensor to the air-ratio control system by the output control device to just before opening the door.

Description

Combustion equipment The present invention relates to a combustion facility that adjusts the ratio of gaseous or liquid fuel supplied through a fuel supply pipe to combustion air supplied through an air supply pipe using an air-ratio control system, supplies the fuel to a burner, and injects the fuel and combustion air from the burner into a furnace for combustion. In particular, the invention is characterized by the fact that even when the amount of incoming air entering the furnace changes significantly, such as when opening or closing the furnace door, and the oxygen concentration inside the furnace changes significantly, the ratio of fuel supplied to the burner to combustion air is appropriately controlled to stably obtain a good combustion state. Conventionally, in a combustion facility, fuel supplied through a fuel supply pipe and combustion air supplied through an air supply pipe are supplied to a burner in a predetermined ratio, and the fuel and combustion air are ejected from the burner into the furnace to be combusted. Here, when combustion is performed in a furnace with a predetermined air-fuel ratio of fuel and combustion air, as described in Patent Document 1, in a furnace using regenerative burners, the actual flow coefficient of the burner is determined by measuring the pressure and valve opening, and the flow coefficient of the burner is treated as a measured value corresponding to the change in the fluid state, thereby controlling the amount of combustion while maintaining a constant air-fuel ratio in the furnace. However, in the case of the invention described in Patent Document 1, the actual flow rate coefficient of the burner is determined by measuring the pressure and valve opening, and the flow rate coefficient of the burner is treated as an actual value that matches the change in the state of the fluid. Therefore, when the amount of incoming air entering the furnace changes significantly, such as when the furnace door is opened or closed, and the oxygen concentration inside the furnace changes significantly, it is very difficult to respond quickly to maintain the air ratio inside the furnace. For example, when the furnace door is opened and the amount of incoming air entering the furnace increases significantly, if the ratio of the combustion air supplied to the burner is reduced to maintain the air ratio inside the furnace and the air ratio in the burner is drastically reduced, unburned gas is ejected from the burner, making it easy for soot or carbon monoxide to be generated, which has the problem of lowering safety during operation or causing adverse effects on products or the environment. In addition, in the prior art, as shown in Patent Document 2, in a method of operating a continuous heating furnace having a plurality of combustion zones equipped with combustion burners, when the burners of some combustion zones are operating in a extinguished or low-load state, a target value of at least the oxygen concentration in the corresponding combustion zone is obtained, and the air ratio of each combustion zone on the upstream side is controlled based on the target value. Furthermore, an oxygen concentration meter and a CO concentration meter are installed on the combustion exhaust gas discharge side of each combustion zone, and when the burners of some combustion zones are operating in a extinguished or low-load state, a target value of at least the oxygen concentration in the corresponding combustion zone is obtained, and the air ratio of each combustion zone on the upstream side is obtained based on the target value, and one of the CO concentration target value and the oxygen concentration target value is set according to the obtained air ratio, and one of the oxygen concentration and the CO concentration is controlled based on the set target value and the measured values of the oxygen concentration meter and the CO concentration meter. However, in the case described in Patent Document 2, as described above, oxygen concentration meters and CO concentration meters are installed on the combustion exhaust gas discharge side of each combustion zone, and when some combustion zone burners are operating in a extinguished or low-load state, a target value for at least the oxygen concentration in the corresponding combustion zone is obtained. In order to determine the air ratio of each combustion zone upstream based on the target value, similar to the case where the furnace door is opened and closed as described in Patent Document 1, it is very difficult to rapidly respond to situations where the amount of incoming air entering the furnace changes significantly and the oxygen concentration inside the furnace changes significantly. For example, in a furnace with multiple burners, if the combustion of some burners is stopped and only cooling air to prevent thermal deformation of the fuel nozzle is introduced into the furnace, thereby significantly increasing the amount of incoming air entering