Thermal storage combustion equipment

Abstract

In a regenerative combustion system equipped with a pair of regenerative burners that alternately perform combustion and heat storage operations, the system enables rapid detection of abnormalities in the exhaust valve installed in the exhaust gas pipe that exhausts combustion exhaust gas from the furnace through the heat storage section. [Solution] In a regenerative combustion system equipped with a pair of regenerative burners 10a and 10b that alternately perform combustion and heat storage operations, oxygen concentration sensors 36a and 36b are installed downstream of the exhaust valves 34a and 34b in the exhaust gas pipes 32a and 32b that exhaust combustion exhaust gas Gr from the furnace 1 through the heat storage sections 20a and 20b. The oxygen concentration in the gas flowing through the exhaust gas pipes of the regenerative burners during combustion is measured by the oxygen concentration sensors to detect any abnormalities in the exhaust valves.

Description

Technical Field

[0001] The present invention relates to a regenerative combustion facility equipped with a pair of regenerative burners that alternately perform a combustion operation and an exhaust operation. In the combustion operation, a supply valve provided on an air supply pipe is opened to introduce combustion air into a heat storage section, the combustion air is heated in the heat storage section and ejected into a furnace, and fuel gas is combusted in the furnace; in the exhaust operation, flue gas generated after combustion of fuel gas is guided from the furnace to the heat storage section to allow the heat of the flue gas to be stored in the heat storage section, and an exhaust valve provided on an exhaust gas pipe is opened to discharge the flue gas. The present invention is particularly characterized in that, in the above-mentioned regenerative burner, when performing the combustion operation in which the supply valve provided on the air supply pipe is opened to introduce combustion air into the heat storage section, the combustion air is heated in the heat storage section and ejected into the furnace, and the fuel gas is combusted in the furnace, it prevents the problem that: part of the combustion air leaks from the exhaust valve provided on the exhaust gas pipe and is discharged, so that the amount of combustion air mixed with the fuel gas for combustion decreases, the heat in the heat storage section is not consumed by the combustion air, the temperature of the heat storage section rises, consequently the flue gas cannot sufficiently exchange heat with the heat storage body, and the flue gas passes through the exhaust valve at a high temperature, which causes early thermal damage to the exhaust valve, or the fuel gas is combusted at a low air ratio, generating soot that contaminates the interior of the furnace, or producing unburned fuel gas.

Background Art

[0002] Conventionally, in industrial furnaces for heat-treating various workpieces such as steel materials, in order to effectively utilize the heat of flue gas generated from fuel combustion in the furnace, a regenerative combustion facility equipped with a pair of regenerative burners that alternately perform a combustion operation and an exhaust operation has been widely used. In the combustion operation, a supply valve provided on an air supply pipe is opened to introduce combustion air into a heat storage section, the combustion air is heated in the heat storage section and ejected into the furnace, and the heated combustion air is mixed with fuel gas and combusted in the furnace; in the exhaust operation, flue gas generated after combustion of fuel gas is guided from the furnace to the heat storage section to allow the heat of the flue gas to be stored in the heat storage section, and an exhaust valve provided on an exhaust gas pipe is opened to discharge the flue gas.

[0003] Furthermore, in the regenerative combustion equipment described above, an exhaust fan is installed in the exhaust pipe to create negative pressure inside the exhaust pipe and draw in the combustion exhaust gas in order to release the combustion exhaust gas by opening an exhaust valve installed in the exhaust pipe.

[0004] In the aforementioned regenerative burner, if the combustion and exhaust operations are performed alternately as described above, the temperature of the combustion exhaust gas after heat storage in the heat storage section is high. Repeatedly opening the exhaust valve to release the combustion exhaust gas causes the exhaust valve to deteriorate, and other causes can lead to malfunctions in the exhaust valve, making it impossible to completely close the exhaust valve, or leaving a gap even if the valve plate is closed.

[0005] In this state, if the supply valve provided in the air supply pipe is opened as described above to guide combustion air to the heat storage section, the combustion air is heated in the heat storage section and ejected into the furnace, and the combustion operation is performed in which the fuel gas is burned in the furnace, then a portion of the combustion air guided to the heat storage section is guided through the gap in the valve plate of the exhaust valve and other such gaps into the exhaust gas pipe, which is under negative pressure, and is exhausted.

[0006] Furthermore, if some of the combustion air supplied from the air supply pipe to the heat storage unit leaks out through the exhaust valve and is exhausted through the exhaust gas pipe, the amount of combustion air supplied to the heat storage unit decreases. As a result, the heat in the heat storage unit is not consumed by the combustion air, the temperature of the heat storage unit rises, and the combustion exhaust gas cannot adequately exchange heat with the heat storage material. This can lead to the exhaust valve being damaged by heat prematurely as the combustion exhaust gas passes through the exhaust valve at a high temperature. In addition, problems such as combustion of fuel gas at a low air-fuel ratio, generation of soot and contamination of the furnace, and generation of unburned fuel gas can occur.

[0007] Furthermore, conventionally, as shown in Patent Document 1, combustion exhaust gas is guided from the furnace to a heat storage unit to store the heat of the combustion exhaust gas in the heat storage unit, and when the combustion exhaust gas is exhausted by opening an exhaust valve provided in the exhaust gas pipe, outside air is taken in to lower the temperature of the combustion exhaust gas guided through the exhaust gas pipe to the exhaust valve, thereby preventing damage to the exhaust valve.

[0008] However, in the device shown in Patent Document 1, as described above, a malfunction occurred in the exhaust valve, making it impossible to completely close the exhaust valve. As a result, it was not possible to properly detect that a portion of the combustion air supplied from the air supply pipe to the heat storage unit was being guided through the exhaust valve to the exhaust gas pipe, which was under negative pressure, and being exhausted.

[0009] Furthermore, Patent Document 2 describes a method in which a regenerative burner is shut down, the gas temperature between the heat storage unit and the exhaust valve is measured during the shutdown period, and if the gas temperature exceeds a predetermined level, air is introduced from the air supply pipe to cool it down and prevent damage to the exhaust valve.

[0010] However, while the method described in Patent Document 2 detects danger by measuring the gas temperature, the temperature of the gas is affected by heat accumulation and radiation from surrounding heated parts, and it tends to stagnate in areas where it does not flow easily, resulting in slow temperature changes and making it difficult to accurately and quickly detect abnormalities. [Prior art documents] [Patent Documents]

[0011] [Patent Document 1] Patent No. 7311482 [Patent Document 2] Patent No. 4801185 [Disclosure of the Invention] [Problems that the invention aims to solve]

[0012] The present invention aims to solve the aforementioned problems in a regenerative combustion system equipped with a regenerative burner that alternately performs the following operations: a combustion operation in which a supply valve provided in an air supply pipe is opened to guide combustion air to a heat storage section, the combustion air is heated in the heat storage section and injected into the furnace to burn fuel gas in the furnace; and an exhaust operation in which the combustion exhaust gas after the fuel gas has been burned is guided from the furnace to the heat storage section to store the heat of the combustion exhaust gas in the heat storage section, and the combustion exhaust gas is exhausted by opening an exhaust valve provided in the exhaust gas pipe.

[0013] In other words, in a regenerative burner installed in a regenerative combustion equipment as described above, when a supply valve installed in the air supply pipe is opened to guide combustion air to the heat storage section, the air is heated in the heat storage section and ejected into the furnace to burn the fuel gas in the furnace, the objective of the present invention is to prevent such problems by detecting signs of these issues and enabling parts replacement or maintenance before the combustion exhaust gas is generated. [Means for solving the problem]

[0014] In the regenerative combustion equipment according to the present invention, in order to solve the above-mentioned problems, a regenerative combustion equipment equipped with a regenerative burner alternately performs the following operations: a combustion operation in which a supply valve provided in the air supply pipe is opened to guide combustion air to the heat storage section, the combustion air is heated in the heat storage section and injected into the furnace to burn fuel gas in the furnace; and an exhaust operation in which the combustion exhaust gas after the fuel gas has been burned is guided from the furnace to the heat storage section to store the heat of the combustion exhaust gas in the heat storage section, and the combustion exhaust gas is exhausted by opening the exhaust valve provided in the exhaust gas pipe. In this regenerative combustion equipment, an oxygen concentration sensor is provided downstream of the exhaust valve provided in the exhaust gas pipe, and the oxygen concentration sensor measures the oxygen concentration contained in the gas flowing through the exhaust gas pipe of the regenerative burner during the combustion operation to detect abnormalities in the exhaust valve.

[0015] Furthermore, as in the regenerative combustion equipment according to the present invention, an oxygen concentration sensor is installed downstream of the exhaust valve in the exhaust gas pipe. By using this oxygen concentration sensor to detect combustion air leaks based on the oxygen concentration in the gas flowing through the exhaust gas pipe of the regenerative burner during combustion operation, the system becomes unaffected by radiation and stagnation, as is the case when measuring temperature, and abnormalities in combustion air leaks (actually oxygen in the air) from the exhaust valve can be quickly detected.

[0016] Furthermore, in the regenerative combustion equipment according to the present invention, when measuring the oxygen concentration contained in the gas flowing through the exhaust gas pipe of the regenerative burner during combustion operation using an oxygen concentration sensor as described above, the exhaust valve provided in the exhaust gas pipe can be closed, and then the supply valve provided in the air supply pipe that supplies combustion air to the regenerative burner can be opened to measure the oxygen concentration contained in the gas flowing through the exhaust gas pipe of the regenerative burner.

[0017] Normally, the exhaust valve is closed and the supply valve is opened simultaneously. However, when using a butterfly valve as illustrated in the embodiment, it takes several seconds for this operation to complete. During this time, some of the combustion air supplied from the air supply pipe to the heat storage unit is short-circuited through the lower space of the heat storage unit and the exhaust valve to the exhaust gas pipe. This causes a large amount of air to flow into the exhaust gas pipe temporarily, leading the oxygen concentration sensor to mistakenly detect a leak. Therefore, accurate measurements cannot be taken until some time has passed after the exhaust valve is closed. However, by closing the exhaust valve first, the short-circuit can be prevented, allowing for accurate measurements to be taken immediately after the exhaust valve is closed.

[0018] Furthermore, in the regenerative combustion equipment according to the present invention, a detection operation timing is set for an operation to detect an abnormality in the exhaust valve, and at the aforementioned detection operation timing, the oxygen concentration sensor can measure the oxygen concentration contained in the gas flowing through the exhaust gas pipe of the regenerative burner during combustion operation. At this detection operation timing, in order to accurately measure whether a portion of the combustion air led from the air supply pipe to the heat storage unit is leaking from the exhaust valve and being exhausted through the exhaust gas pipe, it is preferable that, when performing combustion operation, after closing the exhaust valve provided in the exhaust gas pipe as described above, the supply valve provided in the air supply pipe that supplies combustion air to the regenerative burner is opened, and the oxygen concentration contained in the gas flowing through the exhaust gas pipe of the regenerative burner is measured by the oxygen concentration sensor.

[0019] Furthermore, in the regenerative combustion equipment according to the present invention, a suction pipe can be provided in the exhaust gas pipe downstream of the exhaust valve to draw in the gas flowing through the exhaust gas pipe and guide it to the oxygen concentration sensor. In this way, when combustion air leaks from the exhaust valve and flows through the exhaust gas pipe, the gas flowing through the exhaust gas pipe can be drawn in by the suction pipe and reliably guided to the oxygen concentration sensor, thereby enabling measurement of the oxygen concentration. [Effects of the Invention]

[0020] In the regenerative combustion equipment of the present invention, an oxygen concentration sensor is provided downstream of an exhaust valve provided in an exhaust gas pipe as described above, and the oxygen concentration sensor measures the oxygen concentration contained in the gas flowing through the exhaust gas pipe of the regenerative burner during combustion operation to detect abnormality of the exhaust valve. Therefore, during combustion operation, the oxygen concentration sensor can detect earlier that part of the combustion air guided to the heat storage unit leaks from the exhaust valve provided in the exhaust gas pipe and is exhausted, compared with the case of using a conventional temperature sensor.

[0021] As a result, in the regenerative combustion equipment of the present invention, during combustion operation, the amount of combustion air mixed with fuel gas for combustion decreases, the heat in the heat storage unit is not consumed by the combustion air, and the temperature of the heat storage unit increases. Consequently, the combustion exhaust gas cannot sufficiently exchange heat with the heat storage body, and when the combustion exhaust gas passes through the exhaust valve at a high temperature, the exhaust valve may suffer thermal damage at an early stage, or fuel gas is burned in a state of low air ratio to generate soot, which contaminates the furnace interior and generates unburned fuel gas. The present invention allows early detection of such signs to enable component replacement and maintenance before such problems occur, thereby enabling early prevention of such problems. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] [Figure 1] 1 shows a regenerative combustion equipment according to an embodiment of the present invention. In one regenerative burner, a supply valve provided in an air supply pipe is opened to guide combustion air to a heat storage unit, the combustion air is heated in the heat storage unit and ejected into a furnace, and a combustion operation of mixing the air with fuel gas in the furnace for combustion is performed. In the other regenerative burner, combustion exhaust gas after combustion of fuel gas is guided from the furnace interior to the heat storage unit, so that the heat of the combustion exhaust gas is stored in the heat storage unit, and an exhaust operation of opening the exhaust valve provided in an exhaust gas pipe to exhaust the combustion exhaust gas is performed. This is a schematic explanatory diagram showing the above state. [Figure 2]In the regenerative combustion facility of the aforementioned embodiment, an oxygen concentration sensor is provided downstream of an exhaust valve provided in an exhaust gas pipe, and the oxygen concentration sensor measures the oxygen concentration contained in the gas leaking from the exhaust valve and flowing through the exhaust gas pipe during combustion operation, and this is a schematic explanatory diagram showing a state where an abnormality of the exhaust valve is detected. [Figure 3] When switching from an exhaust operation to a combustion operation in one regenerative burner of the regenerative combustion facility in the aforementioned embodiment, (A) and (B) are partial schematic explanatory diagrams showing an example of operating an exhaust valve provided in an exhaust gas pipe and a supply valve provided in an air supply pipe. [Figure 4] In the regenerative combustion facility of the aforementioned embodiment, this is a partial schematic explanatory diagram showing an example in which a bypass pipe for using a suction blower to suck exhaust gas into the oxygen concentration sensor is provided. BEST MODE FOR CARRYING OUT THE INVENTION

[0023] Hereinafter, a regenerative combustion facility according to an embodiment of the present invention will be specifically described with reference to the accompanying drawings. Note that the regenerative combustion facility according to the present invention is not limited to what is shown in the following embodiment, and can be appropriately modified and implemented without changing the gist of the invention.

[0024] In the regenerative combustion facility of this embodiment, as shown in FIG. 1, a paired first regenerative burner 10a and second regenerative burner 10b are provided so as to face each other toward the inside of a furnace 1, and each of the paired regenerative burners 10a and 10b is provided with fuel injection nozzles 11a and 11b respectively for injecting fuel gas G toward the inside of the furnace 1.

[0025] Furthermore, in the regenerative combustion equipment of this embodiment, combustion air is supplied by a blower 21 to the respective heat storage sections 20a and 20b in each of the regenerative burners 10a and 10b, where the heat storage body x is housed, through air supply pipes 22a and 22b, respectively. Each of the air supply pipes 22a and 22b is provided with a supply valve 23a and 23b, respectively.

[0026] Furthermore, in the regenerative combustion equipment of this embodiment, when exhausting the combustion exhaust gas Gr after burning the fuel gas G as described above from inside the furnace 1 through the intake and exhaust ports 24a and 24b of each regenerative burner 10a and 10b and through the heat storage units 20a and 20b, the combustion exhaust gas Gr inside the furnace 1 is sucked in by a suction blower 31 and guided to the heat storage units 20a and 20b, and after the heat of the combustion exhaust gas Gr is stored in the heat storage body x housed in each heat storage unit 20a and 20b, the combustion exhaust gas Gr is exhausted through the exhaust gas pipes 32a and 32b provided in each regenerative burner 10a and 10b, and exhaust valves 34a and 34b are provided in each exhaust gas pipe 32a and 32b, respectively. In this embodiment, the supply valves 23a and 23b and the exhaust valves 34a and 34b are shown as butterfly valves, but other valves such as solenoid valves may also be used.

[0027] In this embodiment of the regenerative combustion equipment, suction pipes 35a and 35b are provided downstream of the exhaust valves 34a and 34b installed in each of the exhaust gas pipes 32a and 32b, respectively, to draw in a portion of the gas flowing through each exhaust gas pipe 32a and 32b. The gas drawn in by the suction pipes 35a and 35b is guided to oxygen concentration sensors 36a and 36b to measure the oxygen concentration contained in the gas flowing through the exhaust gas pipes 32a and 32b. The oxygen concentration sensors 36a and 36b are paired with a suction pump (not shown) to draw in the gas flowing through the exhaust gas pipes 32a and 32b. To draw in the gas, it may be drawn in naturally into the suction pipes 35a and 35b by the positive pressure inside the exhaust gas pipes 32a and 32b, or, as shown in Figure 4, a bypass pipe 37 may be connected and the suction force of a suction blower 31 may be used.

[0028] Furthermore, the oxygen concentration measured by the respective oxygen concentration sensors 36a and 36b is output to the abnormality detection device 40, which then detects abnormalities in the respective exhaust valves 34a and 34b based on the measured oxygen concentration.

[0029] In this embodiment of the regenerative combustion equipment, in the regenerative burner 10a that performs the combustion operation, as shown in Figure 1, the supply valve 23a provided on the air supply pipe 22a is opened, and combustion air Air is guided through the air supply pipe 22a to the heat storage section 20a where the heat storage body x is housed. The heat stored in the heat storage body x housed in the heat storage section 20a heats the combustion air Air, and the heated combustion air Air is injected into the furnace 1 through the intake and exhaust port 24a of the regenerative burner 10a. At the same time, fuel gas G is injected into the furnace 1 from the fuel injection nozzle 11a, so that the fuel gas G is mixed with the combustion air Air in the furnace 1 and combusted. In this case, in the regenerative burner 10a, the exhaust valve 34a provided on the exhaust gas pipe 32a is kept closed so that the combustion exhaust gas Gr is not guided from inside the furnace 1 through the intake and exhaust port 24a to the heat storage section 20a.

[0030] On the other hand, in the regenerative burner 10b that performs exhaust operation, as shown in Figure 1, the supply valve 23b provided in the air supply pipe 22b is closed to prevent combustion air from being introduced into the heat storage unit 20b, and the fuel gas G is not supplied to the fuel injection nozzle 11b. At the same time, the exhaust valve 34b provided in the exhaust gas pipe 32b is opened, and the combustion exhaust gas Gr after the fuel gas G has been burned in the furnace 1 is introduced into the heat storage unit 20b through the intake and exhaust port 24b by the suction blower 31. After the heat from the combustion exhaust gas Gr is stored in the heat storage body x housed in the heat storage unit 20b, this combustion exhaust gas Gr is exhausted through the exhaust gas pipe 32b with the exhaust valve 34b open.

[0031] In this case, if the pair of heat-retaining burners 10a and 10b are configured to alternately perform the combustion operation and exhaust operation, the temperature of the combustion exhaust gas Gr after heat storage in each heat storage section 20a and 20b is high. As a result of repeatedly opening the exhaust valves 34a and 34b and exhausting the combustion exhaust gas Gr through the exhaust pipes 32a and 32b as described above, the exhaust valves 34a and 34b may deteriorate, or other malfunctions may occur in the exhaust valves 34a and 34b, making it impossible to completely close them.

[0032] In this way, if it becomes impossible to completely close each exhaust valve 34a, 34b, for example, as shown in Figure 2, in a regenerative burner 10a that performs combustion, if the supply valve 23a is opened and combustion air is guided to the heat storage unit 20a through the air supply pipe 22a, a portion of the combustion air guided to the heat storage unit 20a will be sucked in by the suction blower 31 and guided to the exhaust gas pipe 32a through the exhaust valve 34a, which is not completely closed, and exhausted.

[0033] Furthermore, if a portion of the combustion air Air that is introduced to the heat storage unit 20a is introduced to the exhaust gas pipe 32a through the exhaust valve 34a, which is not completely closed, the amount of combustion air Air introduced to the heat storage unit 20a decreases, the heat in the heat storage unit 20a is not consumed by the combustion air Air, the temperature of the heat storage unit 20a rises, the combustion exhaust gas Gr cannot adequately exchange heat with the heat storage body x, and the combustion exhaust gas Gr passes through the exhaust valve 34a at a high temperature, causing the exhaust valve 34a to be thermally damaged prematurely, the fuel gas G to be burned at a low air-fuel ratio, soot is generated and the inside of the furnace 1 is contaminated, and unburned fuel gas G is generated.

[0034] Therefore, in the regenerative combustion equipment of this embodiment, in the regenerative burner 10a that performs combustion, the gas flowing through the exhaust gas pipe 32a is guided to the oxygen concentration sensor 36a through a suction pipe 35a provided in the exhaust gas pipe 32a downstream of the exhaust valve 34a, as described above. The oxygen concentration contained in the gas flowing through the exhaust gas pipe 32a is measured by the oxygen concentration sensor 36a, and the measurement result is output to the abnormality detection device 40. If the measured oxygen concentration rises to a predetermined value or higher, even during combustion, the abnormality detection device 40 detects an abnormality in the exhaust valve 34a and instructs the device to replace the exhaust valve 34a.

[0035] As a result, in the regenerative combustion equipment of this embodiment, abnormalities in the exhaust valve 34a can be detected promptly, and a portion of the combustion air Air led to the heat storage unit 20a can be quickly prevented from being led to the exhaust gas pipe 32a and exhausted through the exhaust valve 34a. This prevents problems such as the exhaust valve 34a being prematurely damaged by heat due to the exhaust gas Gr passing through the exhaust valve 34a at a high temperature, the fuel gas G being burned at a low air-to-air ratio, soot being generated and the inside of the furnace 1 being contaminated, or unburned fuel gas G being generated. By quickly and reliably detecting signs of these problems and performing parts replacement or maintenance, such problems can be prevented early and reliably.

[0036] Furthermore, in the regenerative combustion equipment of this embodiment, as shown in Figure 3(A), in one regenerative burner 10a, the supply valve 23a provided on the air supply pipe 22a is closed to prevent combustion air from being introduced into the heat storage unit 20a, while the exhaust valve 34a provided on the exhaust gas pipe 32a is opened to introduce combustion exhaust gas Gr into the heat storage unit 20a and store the heat of the combustion exhaust gas Gr in the heat storage unit 20a. When switching from the exhaust operation, in which this combustion exhaust gas Gr is exhausted through the exhaust gas pipe 32a from the exhaust valve 34a, to the combustion operation shown in Figure 2, it is preferable, as shown in Figure 3(B), to keep the supply valve 23a provided on the air supply pipe 22a closed while operating to close the exhaust valve 34a, and then, as shown in Figure 2, to open the supply valve 23a provided on the air supply pipe 22a to introduce combustion air into the heat storage unit 20a.

[0037] Normally, the operation of closing the exhaust valve 34a and opening the supply valve 23a are performed simultaneously. However, when using a butterfly valve as shown in the figure, it takes several seconds for this operation to complete. During this time, some of the combustion air (Air) that is guided from the air supply pipe 22a to the heat storage unit 20a is short-circuited through the space below the heat storage unit 20a and the exhaust valve 34a to the exhaust gas pipe 32a. As a result, a large amount of combustion air temporarily flows into the exhaust gas pipe 32a, causing the oxygen concentration sensor 36a to mistakenly detect a leak. Therefore, it is conceivable that accurate measurements cannot be taken until some time has passed after the exhaust valve 34a has closed. However, by closing the exhaust valve 34a first, the short-circuit can be prevented, allowing for accurate measurements to be taken immediately after the exhaust valve 34a is closed.

[0038] This operation does not need to be performed every time the supply and exhaust are switched. Instead, a detection operation timing can be set (such as setting it as "detection operation mode") to detect an abnormality in the exhaust valve 34a, and at the aforementioned detection operation timing, the oxygen concentration sensor 36a can be used to measure the oxygen concentration in the gas flowing through the exhaust gas pipe 32a of the regenerative burner 10a during combustion. This operation can be performed at any time or periodically.

[0039] Furthermore, since the above operation temporarily closes both the exhaust valve 34a and the supply valve 23a, it may affect the pressure inside furnace 1. Therefore, it is best to perform this operation at a time that does not affect operation, such as when there is no object to be heated (not shown) inside furnace 1. [Explanation of symbols]

[0040] 1: Furnace 10a, 10b: Rechargeable burner 11a, 11b: Fuel injection nozzles 20a, 20b: Heat storage part 21: Blower 22a, 22b: Air supply pipe 23a, 23b: Supply valve 24a, 24b: Supply / exhaust port 31: Suction blower 32a, 32b: Exhaust pipe 34a, 34b: Exhaust valve 35a, 35b: Suction tube 36a, 36b: Oxygen concentration sensor 37: Bypass pipe 40: Anomaly detection device Air: Combustion air G: Fuel gas Gr: Combustion exhaust gas x : Heat storage body

Claims

1. A regenerative combustion system equipped with a pair of regenerative burners that alternately perform a combustion operation in which a supply valve provided in an air supply pipe is opened to guide combustion air to a heat storage section, the combustion air is heated in the heat storage section and injected into the furnace to burn fuel gas in the furnace, and an exhaust operation in which the combustion exhaust gas after the fuel gas has been burned is guided from the furnace to the heat storage section to store the heat of the combustion exhaust gas in the heat storage section, and the combustion exhaust gas is exhausted by opening an exhaust valve provided in the exhaust gas pipe, wherein an oxygen concentration sensor is provided downstream of the exhaust valve provided in the exhaust gas pipe, and the oxygen concentration sensor measures the oxygen concentration contained in the gas flowing through the exhaust gas pipe of the regenerative burner during the combustion operation to detect an abnormality in the exhaust valve.

2. In the regenerative combustion equipment according to claim 1, when measuring the oxygen concentration contained in the gas flowing through the exhaust gas pipe of the regenerative burner during combustion operation using the oxygen concentration sensor, the exhaust valve provided in the exhaust gas pipe is closed, and then the supply valve provided in the air supply pipe that supplies combustion air to the regenerative burner is opened to measure the oxygen concentration contained in the gas flowing through the exhaust gas pipe of the regenerative burner.

3. A regenerative combustion system according to claim 1 or claim 2, characterized in that a detection operation timing is set for performing an operation to detect an abnormality in the exhaust valve, and at the detection operation timing, the oxygen concentration sensor measures the oxygen concentration contained in the gas flowing through the exhaust gas pipe of the regenerative burner during combustion operation.

4. A regenerative combustion system according to claim 1 or claim 2, characterized in that a suction pipe is provided in the exhaust gas pipe downstream of the exhaust valve to draw in the gas flowing through the exhaust gas pipe and guide it to the oxygen concentration sensor.

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