JP5256169B2 - Combustion monitoring apparatus, combustion monitoring method and combustion control system for heating furnace - Google Patents

Description

  The present invention relates to a combustion monitoring device, a combustion monitoring method, and a combustion control system in an industrial kiln (including a metal material heat treatment furnace).

  Usually, a regenerative burner that performs regenerative switching combustion is used in a plurality of pairs per combustion zone (corresponding to a heating furnace) with one pair as a minimum unit. That is, as shown in FIG. 4, in the heating furnace 305, the flow control of fuel, combustion air, and exhaust gas is performed by collectively combining a pair of regenerative burners 301 and 302 and a pair of regenerative burners 303 and 304. Has been done.

  In such a regenerative burner 301, 302, 303, 304, when switching from heat storage to combustion or from combustion to heat storage, the inrush flow rate of fuel / combustion air / exhaust gas is suppressed and the abnormal combustion state is suppressed. Have been proposed (see, for example, Patent Document 1).

  In order to achieve the above object, in the invention according to Patent Document 1, as shown in FIG. 5, fuel switching valves 321, 322, 323, 324, combustion air switching valves 371, 372, 373, 374 When the exhaust gas switching valves 411, 412, 413, 414 are sequentially switched, the switching valves 321, 322, 323, 324, 371, 372, 373, 374, 411, 412, 413, 414 are switched in the closing direction, respectively. , 372, 372, 373, 374, 411, 412, 413, 414 and the corresponding fuel flow rate control valve 327, combustion air flow rate control valve 377, and exhaust gas flow rate control The opening degree of the valve 417 is sequentially changed to each switching valve 321, 322, 323, 324, 371, 372, 373, 374, 411, 12, 413, and 414, each of the switching valves 321, 322, 323, 324, 371, 372, 373 is closed in a closing direction by a certain amount from the opening immediately before the start of the switching operation. 374, 411, 412, 413, 414, each flow rate adjustment corresponding to each switching valve 321,322,323,324,371,372,373,374,411,412,413,414 The operation of returning the opening degrees of the valves 327, 377, and 417 to the opening degree immediately before the start of the switching operation is started, and when the valve opening degrees of the respective flow rate control valves 327, 377, and 417 approach the opening degree immediately before the switching operation. The flow rate control of each flow rate adjustment valve 327, 377, 417 is resumed.

  As shown in FIG. 5, in the invention according to Patent Document 1, for example, the burner bodies 301a and 303a of the regenerative burners 301 and 303 that make a pair do not clog and leak from the pipes 311 and 313. In a normal state where neither occurs, the fuel pressure in front of the burner body 301a and the fuel pressure in front of the burner body 303a exceed the lower limit pressure value of 30 Pa and are stable (see points K and K). In such a state, when the fuel supplied from the fuel tank 329 is monitored and measured by the fuel flow meter 328, the measurement result value of the process amount (PV) of the total flow rate of the fuel in the burner main bodies 301a and 303a is an alarm. The level of the PV value to be reported (lower limit flow rate value) is far exceeded (see the dot).

JP-A-10-196936

  However, as shown in FIG. 5, in the invention according to Patent Document 1, for example, when the burner body 304a of the burner bodies 302a and 304a of the pair of heat storage burners 302 and 304 is clogged, the burner body The pressure of the fuel before 304a may become a lower limit pressure value of 30 Pa or less (see point D). Conversely, the fuel pressure in front of the burner body 302a increases so as to exceed the lower limit pressure value 30 Pa so as to compensate for the decrease in the fuel pressure in front of the burner body 304a (see the point). Even if such an abnormality has occurred, when the fuel supplied from the fuel tank 329 is monitored and measured by the fuel flow meter 328, the measurement results of the process amount (PV) of the total flow rate of the fuel in the burner main bodies 302a and 304a are measured. The value slightly exceeds the level (lower limit flow rate value) of the PV value at which an alarm is issued (see the point). Therefore, the fuel flow meter 328 does not have a configuration for monitoring and measuring the fuel pressure before the burner body 302a and the lower limit pressure value 30Pa of the fuel pressure before the burner body 304a. In the invention according to Patent Document 1 having a configuration that only monitors and measures the above, there is a problem that the abnormality cannot be detected. That is, misfire or the like due to incomplete combustion based on the abnormality cannot be prevented. Although only the fuel pressure and flow rate have been described above, the same can be said for the pressure and flow rate of combustion air.

  An object of the present invention is to provide a combustion monitoring device and a combustion monitoring method for a heating furnace capable of detecting an abnormality (clogging or leakage) of a fuel or combustion air related to a regenerative burner, and to prevent misfire due to incomplete combustion and to stabilize it. An object of the present invention is to provide a combustion control system capable of achieving combustion.

In order to achieve this object, the invention according to claim 1 of the present invention provides:
A heat storage unit that has a heat storage function in the vicinity of the burner body, switches the direction of gas passing through the heat storage unit at predetermined time intervals based on a predetermined sequence, and continues combustion while alternately performing heat storage and combustion A combustion monitoring device for a heating furnace in which a pair of burners is disposed,
The heat storage type burner is disposed so as to correspond to the piping path between the burner body and the fuel switching valve and the piping path between the heat storage portion of each heat storage type burner and the combustion air switching valve, and the predetermined First and second lower limit pressure switches that are set to operate (ON) only during the combustion mode based on the sequence of (1) and to be inactive (OFF) during the heat storage mode;
Applicable when the pressure of fuel in the piping path corresponding to the first and second pressure switches with lower limit in the ON state and the pressure of combustion air in the piping path are equal to or lower than a predetermined lower limit pressure value. A lower limit pressure value detection signal is transmitted from the pressure switch, and the lower limit pressure value detection signal is input, and it is determined that a lower limit pressure value detection signal is transmitted from at least one of the pressure switches. In the case, a determination unit for sending an abnormal signal;
A warning issuing unit for issuing a warning based on the abnormal signal sent from the determination unit;
It is the combustion monitoring apparatus of the heating furnace characterized by including.

The invention described in claim 2
A heat storage unit that has a heat storage function in the vicinity of the burner body, switches the direction of gas passing through the heat storage unit at predetermined time intervals based on a predetermined sequence, and continues combustion while alternately performing heat storage and combustion A combustion monitoring method for a heating furnace in which a pair of burners is disposed,
The piping path between the burner body of each regenerative burner and the fuel switching valve and the piping path between the heat storage section of each regenerative burner and the combustion air switching valve operate only in the combustion mode based on the predetermined sequence. (ON) and first and second lower limit pressure switches with a lower limit set so as to be inactive (OFF) during the heat storage mode, respectively.
Applicable when the pressure of fuel in the piping path corresponding to the first and second pressure switches with lower limit in the ON state and the pressure of combustion air in the piping path are equal to or lower than a predetermined lower limit pressure value. A lower limit pressure value detection signal is transmitted from the pressure switch, and the lower limit pressure value detection signal is input to a determination unit, and the determination unit receives a lower limit pressure value detection signal from at least one of the pressure switches. Is determined to have been transmitted, an abnormal signal transmission step of transmitting an abnormal signal from the determination unit,
Based on the abnormal signal sent in this abnormal signal sending step, a warning issuing step for issuing a warning from the warning issuing unit,
It is the combustion monitoring method of the heating furnace characterized by having.

The invention according to claim 3
A combustion monitoring device for a heating furnace according to claim 1,
According to the burner body of the regenerative burner in which at least one of the pressure of the fuel in the piping path and the pressure of the combustion air in the piping path is equal to or lower than a predetermined lower limit pressure value based on the abnormal signal sent from the determination unit A valve closing signal sending unit for sending a valve closing signal for closing at least the fuel switching valve;
A combustion control system for a heating furnace.

As described above, according to the combustion monitoring apparatus for a heating furnace according to the present invention,
Each heat storage burner is disposed so as to correspond to a piping path from the burner body to the fuel switching valve and a piping path from the heat storage section of each heat storage burner to the combustion air switching valve, and has a predetermined sequence. Based on the first and second lower limit pressure switches set so as to operate (ON) only during the combustion mode and inactive (OFF) during the heat storage mode,
Applicable when the pressure of fuel in the piping path corresponding to the first and second pressure switches with lower limit in the ON state and the pressure of combustion air in the piping path are equal to or lower than a predetermined lower limit pressure value. A lower limit pressure value detection signal is transmitted from the pressure switch, and the lower limit pressure value detection signal is input, and it is determined that a lower limit pressure value detection signal is transmitted from at least one of the pressure switches. In the case, a determination unit for sending an abnormal signal;
A warning issuing unit for issuing a warning based on the abnormal signal sent from the determination unit;
Therefore, it is possible to realize a combustion monitoring apparatus for a heating furnace capable of detecting the occurrence of abnormalities (clogging or leakage) of fuel and combustion air related to the regenerative burner.

Moreover, according to the combustion monitoring method for a heating furnace according to the present invention,
The piping path between the burner body of each regenerative burner and the fuel switching valve and the piping path between the heat storage section of each regenerative burner and the combustion air switching valve operate only in the combustion mode based on the predetermined sequence. (ON) and first and second lower limit pressure switches with a lower limit set so as to be inactive (OFF) during the heat storage mode, respectively.
Applicable when the pressure of fuel in the piping path corresponding to the first and second pressure switches with lower limit in the ON state and the pressure of combustion air in the piping path are equal to or lower than a predetermined lower limit pressure value. A lower limit pressure value detection signal is transmitted from the pressure switch, and the lower limit pressure value detection signal is input to a determination unit, and the determination unit receives a lower limit pressure value detection signal from at least one of the pressure switches. Is determined to have been transmitted, an abnormal signal transmission step of transmitting an abnormal signal from the determination unit,
Based on the abnormal signal sent in this abnormal signal sending step, a warning issuing step for issuing a warning from the warning issuing unit,
Therefore, it is possible to provide a combustion monitoring method for a heating furnace that can detect an abnormality (clogging or leakage) of fuel or combustion air related to a regenerative burner.

Moreover, according to the combustion control system for a heating furnace according to the present invention,
A combustion monitoring apparatus for a heating furnace according to the present invention described above,
A fuel switching valve according to the burner body of the regenerative burner in which at least one of the pressure of the fuel in the piping path and the pressure of the combustion air in the piping path is equal to or lower than a predetermined lower limit pressure value based on the abnormal signal sent from the determination unit A valve closing signal sending part for sending a valve closing signal for closing at least
Therefore, it is possible to realize a combustion control system capable of preventing misfire due to incomplete combustion and achieving stable combustion.

It is a block diagram for demonstrating the structure of the combustion monitoring apparatus and combustion control system of a heating furnace which concerns on this invention. 6 is a graph for explaining the relationship between the length L / diameter d of the fuel pressure guiding tube 41 shown in FIG. 1 and the detection delay time of the fuel pressure at the pressure switch 51; It is a time chart (sequence) figure of the combustion monitoring apparatus of the heating furnace shown in FIG. 1, and a graph for demonstrating transition of the pressure of the fuel before each burner main body. It is a block diagram for demonstrating the structure of the combustion monitoring apparatus of the conventional heating furnace. The time chart (sequence) diagram of the combustion monitoring apparatus for the heating furnace shown in FIG. 4 and the measurement results of the fuel flow rate with the PV flowmeter 328, the MV of the adjustment valve 327, and the transition of the fuel pressure before each burner body will be described. It is a graph for.

  Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a block diagram for explaining the configuration of a combustion monitoring apparatus and combustion control system for a heating furnace according to the present invention, and FIG. 2 is a diagram showing the length L / diameter d of the fuel pressure guiding tube shown in FIG. FIG. 3 is a time chart (sequence) diagram of the combustion monitoring apparatus of the heating furnace shown in FIG. 1 and a transition of fuel pressure before each burner body. It is a graph of.

  Initially, the structure of the combustion monitoring apparatus and combustion control system of a heating furnace is demonstrated using FIG.

  1 is a heat storage type burner composed of a heat storage body 1b as a heat storage section having a heat storage function in the vicinity of the burner body 1a and the burner body 1a, and 2 is a heat storage section as a heat storage section having a heat storage function in the vicinity of the burner body 2a and the burner body 2a. A regenerative burner 3 composed of a body 2b, 3 is a regenerative burner composed of a heat storage section 3b as a heat storage section having a heat storage function in the vicinity of the burner body 3a and the burner body 3a, and 4 is near the burner body 4a and the burner body 4a. A regenerative burner 5 composed of a heat storage body 4b as a heat storage section having a heat storage function is a heating furnace. The regenerative burners 1 and 2 are arranged opposite to each other so as to continue the combustion while alternately performing heat storage and combustion on both sides of the heating furnace 5, and further, heat storage and combustion are performed on the other side of the heating furnace 5. The regenerative burners 3 and 4 are arranged to face each other so as to continue combustion while performing alternately.

  Fuel switch valves 21, 22, 23, and 24 are connected to the burner main bodies 1a, 2a, 3a, and 4a via pipes 11, 12, 13, and 14, respectively. A fuel zone cutoff valve 26, a combustion flow rate adjustment valve 27, a fuel flow meter 28, and a fuel tank 29 are connected in this order via a pipe 25. Further, in the middle of the pipes 11, 12, 13, and 14, pressure switches (PS) 51, 52, 53, and 54 as first pressure switches with a lower limit limit are provided via pressure guiding pipes 41, 42, 43, and 44, respectively. , 55 are connected.

  Further, combustion air switching valves 71, 72, 73, 74 are connected to the heat storage bodies 1b, 2b, 3b, 4b via pipes 61, 62, 63, 64, respectively. 73 and 74 are connected to a combustion air flow rate adjustment valve 77, a combustion air flow meter 78, and a combustion air tank 79 in this order via a pipe 75. Further, in the middle of the pipes 61, 62, 63, 64, pressure switches (PS) 91, 92, 93, 94 as second pressure switches with lower limit via pressure guiding pipes 81, 82, 83, 84, respectively. , 95 are connected. Further, exhaust gas switching valves 111, 112, 113, 114 are connected to the heat storage bodies 1b, 2b, 3b, 4b via pipes 101, 102, 103, 104, and the exhaust gas switching valves 111, 112, 113, 114 are connected. Are connected in order of an exhaust gas flow meter 118, an exhaust gas flow rate control valve 117, and an exhaust gas tank 119 via a pipe 115.

  Pressure switches (PS) 51, 52, 53, 54, 55 and pressure switches (PS) 91, 92, 93, 94, 95 are signal lines 121, 122, 123, 124 for transmitting a lower limit pressure value detection signal, respectively. It is connected to the determination unit 140 via 131, 132, 133, and 134. Furthermore, the determination unit 140 is connected to the warning notification unit 142 via a signal line 141 that transmits an abnormal signal transmitted from the determination unit 140. Further, the pressure switches (PS) 51, 52, 53, 54, 55 and the pressure switches (PS) 91, 92, 93, 94, 95 operate only during the combustion mode based on a predetermined sequence (ON). ) And set to be non-operating (OFF) during the heat storage mode.

  Thus, the combustion monitoring apparatus 150 for the heating furnace is configured.

The regenerative burner (atmospheric pressure large capacity burner) 1, 2, 3, 4 for the heating furnace 5 is often designed in the following condition range.
・ Burner combustion amount range: Turndown 1/5 to 1/10 (stable combustion range)
And fuel supply pressure _P 2: _3~5kPa
・ If the turndown is 1/10 or less, that is, 1/10 or less of the maximum combustion amount, there is a risk of misfire due to unstable combustion.
Pressure ratio {pre-burner supply pressure P ₁ / fuel supply pressure P ₂ } = combustion ratio (turndown) squared.

Therefore, the burner before the supply pressure _{P 1} in the case of turndown 1/10 becomes 30～50Pa. Accordingly, in the present embodiment, the pressure of the fuel in the corresponding pipe 11 path is monitored by the pressure switch (PS) 51, and the predetermined lower limit pressure value of the monitored fuel pressure is set to 30 Pa, for example. Similarly, the pressure switch (PS) 52, 53, 54 sets the lower limit pressure value for monitoring the fuel pressure to 30 Pa. The lower limit pressure value for monitoring the pressure of the combustion air by the pressure switches (PS) 91, 92, 93, 94 is also set to 30 Pa.

  In using the pressure switches (PS) 51, 52, 53, 54, 91, 92, 93, 94 at a predetermined lower limit pressure value = 30 Pa, the pressure guiding tubes 41, 42, 43, 44, 81, 82, 83 are used. , 84 and the detection delay time of the pressure switches (PS) 51, 52, 53, 54, 91, 92, 93, 94 need to be grasped in advance.

  Therefore, as a representative example, the relationship between the length L / diameter d of the pressure guiding tube 41 and the detection delay time of the pressure switch (PS) 51 is previously set for three levels (lower limit pressure values of fuel pressure to be monitored: 20 Pa, 30 Pa, 100 Pa). It was determined by experiment. The result is shown in FIG. From FIG. 2, when the predetermined lower limit pressure value of the fuel pressure is 30 Pa, the length L / diameter d of the pressure guiding tube 41 needs to be about 800 or less in order to make the detection delay time 3 seconds or less. . Preferably, the length L / diameter d of the pressure guiding tube 41 is preferably as small as possible in the range of 300 to 800. Thereby, abnormality detection becomes quick and the timing which closes the fuel switching valve 21 mentioned later at the time of abnormality can also be made quick. However, the length L / diameter d of the pressure guiding tube 41 is not limited to this, and depends on a predetermined lower limit pressure value (for example, 30 to 50 Pa) of the fuel pressure to be monitored and a required detection delay time. To decide. In the present embodiment, the length L / diameter d of the pressure guiding tube 41 is set to 350 to 600.

  The relationship between the length L / diameter d of the pressure guiding tube 41 related to the pressure switch (PS) 51 and the detection delay time of the pressure switch (PS) 51 has been described above, but the pressure switches (PS) 52, 53, 54, 91, The length L / diameter d of the pressure guiding pipes 42, 43, 44, 81, 82, 83, 84 with respect to 92, 93, 94 and the detection delay of the pressure switches (PS) 52, 53, 54, 91, 92, 93, 94 The time relationship shows similar results. Therefore, the length L / diameter d of the pressure guiding tubes 42, 43, 44, 81, 82, 83, 84 is required to be a predetermined lower limit pressure value (for example, 30 to 50 Pa) of the pressure of the fuel / combustion air to be monitored. It may be determined according to the detection delay time. In the present embodiment, the length L / diameter d of the pressure guiding tubes 42, 43, 44, 81, 82, 83, 84 is also set to 350 to 600.

In addition, the determination unit 140 is connected to the valve closing signal transmission unit 160 via a signal line 141 that transmits an abnormal signal transmitted from the determination unit 140. The valve closing signal sending section 160, the fuel zone shutoff valve 26 to close signal transmitting unit 160a, _{N 2} purge valve 31 closes the signal transmitting unit 160 b, closes the fuel switching valve 21, 22, 23, 24 signal transmitting section 160c And a signal sending part 160d for closing the combustion air switching valves 71, 72, 73, 74 and a signal sending part 160e for closing the exhaust gas switching valves 111, 112, 113, 114. A pipe 30 is connected to the pipe 25 immediately after the fuel cutoff valve 26, and an N ₂ purge valve 31 and an N ₂ tank 32 are connected to the pipe 30 in this order. These are added to the combustion monitoring device 150 of the heating furnace to constitute the combustion control system 170.

  Next, a combustion monitoring method by the combustion monitoring device 150 of the heating furnace and a combustion control method by the combustion control system 170 will be described with reference to FIGS.

  In the predetermined time chart (sequence) shown in FIG. 3, the heat storage burners 1 and 3 are in the combustion mode, and the heat storage burners 2 and 4 are in the exhaust (heat storage) mode.

  Based on the predetermined time chart (sequence), the combustion air switching valve 71 of the regenerative burner 1 and the exhaust gas switching valve 112 of the regenerative burner 2 are switched from closed to open. After these are completely switched to open, the fuel switching valve 21 is then switched from closed to open. From the monitoring by the pressure switch (PS) 51, the fuel pressure in front of the burner body 1a has already reached a predetermined lower limit during the time t = 3 (seconds) until the fuel switching valve 21 is completely switched from closed to open. It can be seen that the pressure value (30 Pa) is sufficiently exceeded (see point a).

  After the fuel switching valve 21 is completely switched to open, the combustion air switching valve 73 of the regenerative burner 3 and the exhaust gas switching valve 114 of the regenerative burner 4 are switched from closed to open. After these are completely switched to open, the fuel switching valve 23 is then switched from closed to open. From the monitoring by the pressure switch (PS) 53, the pressure of the fuel in front of the burner body 3a has already reached a predetermined lower limit during the time t = 3 (seconds) until the fuel switching valve 23 is completely switched from closed to open. It can be seen that the pressure value (30 Pa) is sufficiently exceeded (see point a).

  Thereby, it turns out that it is a normal state in which each burner main body 1a, 3a of the regenerative burner 1, 3 is not clogged and there is no leakage from the pipes 11, 13.

  After the regenerative burner 1 burns continuously for a specified time based on the predetermined time chart (sequence), the fuel switching valve 21 is switched from open to closed. After the fuel switching valve 21 is completely closed, the combustion air switching valve 71 and the exhaust gas switching valve 112 are switched from open to closed. After these switches are completely closed, the fuel switching valve 23 is then switched from open to closed, and at the same time, the combustion air switching valve 72 of the regenerative burner 2 and the exhaust gas switching valve 111 of the regenerative burner 1 are switched from closed to open. Can be switched. After these are completely switched to open, the fuel switching valve 22 is then switched from closed to open, and at the same time, the combustion air switching valve 73 and the exhaust gas switching valve 114 are switched from open to closed.

  After the fuel switching valve 22 is completely switched to open, the combustion air switching valve 74 of the heat storage type burner 4 and the exhaust gas switching valve 113 of the heat storage type burner 3 are switched from closed to open. After these are completely switched to open, the fuel switching valve 24 is then switched from closed to open. This sequence is configured so that the above combustion pattern is repeated.

  If the burner body 4a is clogged even when the fuel switching valve 24 is switched from closed to open, the pressure of the fuel in front of the burner body 4a is monitored by the pressure switch (PS) 54 as follows. You can see that That is, the fuel pressure in front of the burner body 4a is below a predetermined lower limit pressure value (30 Pa) during the time t = 3 (seconds) until the fuel switching valve 24 is completely switched from closed to open. (See D). Therefore, a lower limit pressure value detection signal is transmitted from the pressure switch (PS) 54 to the determination unit 140 via the signal line 124, and an abnormal signal is sent from the determination unit 140 to the warning notification unit 142 via the signal line 141. A warning is issued from the warning issuing unit 142 to a supervisor or the like. It can also be seen that the fuel pressure in front of the burner body 4a remains below the predetermined lower limit pressure value (30 Pa) even after the point D has elapsed. It is also possible to detect misfire or the like due to incomplete combustion based on this abnormality.

  As described above, when the burner body 4a is clogged, the fuel pressure in front of the burner body 2a exceeds the lower limit pressure value 30Pa so as to compensate for the decrease in the fuel pressure in front of the burner body 4a. Therefore, the lower limit pressure value detection signal is not transmitted from the pressure switch (PS) 52 to the determination unit 140 via the signal line 122.

  In the present embodiment, the abnormality due to fuel clogging related to the heat storage burner has been described as an example, but the present invention is not necessarily limited thereto. For example, leakage of fuel from a pipe connected to the regenerative burner and occurrence of abnormalities (clogging or leakage) of combustion air related to the regenerative burner can be detected based on the same technical idea as described above. That is, when the pressure of the fuel in the piping path corresponding to the first and second pressure switches with the lower limit in the ON state and the pressure of the combustion air in the piping path are equal to or lower than a predetermined lower limit pressure value, it corresponds. A lower limit pressure value detection signal is transmitted from the pressure switch, and the lower limit pressure value detection signal is input to the determination unit 140. The determination unit 140 receives a lower limit pressure value detection signal from at least one of the pressure switches. When it is determined that the message has been transmitted, an abnormality signal can be transmitted from the determination unit 140, and a warning can be issued from the warning notification unit 142 based on the abnormality signal.

The abnormal signal transmitted from the determination unit 140 via the signal line 141 is transmitted not only to the warning notification unit 142 but also to the valve closing signal transmission unit 160. Thereby, a signal for closing the fuel zone cutoff valve 26 is sent from the signal sending unit 160a to the fuel zone cutoff valve 26, and the fuel zone cutoff valve 26 is closed. At the same time, a signal for closing the N ₂ purge valve 31 is sent from the signal sending unit 160b to the N ₂ purge valve 31, and the N ₂ purge valve 31 is also closed.

Receiving a signal fuel zone shutoff valve 26 and the N ₂ purge valve 31 is closed, a signal for closing the fuel switching valve 24 from the signal transmitting unit 160c is sent to the fuel switching valve 24, the fuel switching valve 24 is closed. At the same time, a signal for closing the combustion air switching valve 74 is sent from the signal sending section 160d to the combustion air switching valve 74, and a signal for closing the combustion air switching valve 74 and closing the exhaust gas switching valve 114 from the signal sending section 160e is exhaust gas switching. The gas is sent to the valve 114 and the exhaust gas switching valve 114 is closed. Accordingly, it is possible to prevent misfire due to incomplete combustion based on abnormality due to clogging of fuel related to the regenerative burner and to achieve stable combustion.

  Further, in the present embodiment, as in the case of the combustion monitoring method described above, the present invention is not limited to only abnormalities due to fuel clogging related to the regenerative burner. For example, in the case of leakage of fuel from a pipe connected to a regenerative burner or occurrence of abnormality (clogging or leakage) of combustion air related to a regenerative burner, based on the same technical idea of the present invention as described above, This makes it possible to prevent misfire due to complete combustion and achieve stable combustion.

In the present embodiment, the fuel zone cutoff valve 26, the N ₂ purge valve 31, the fuel switching valve 24, the combustion air switching valve 74, and the exhaust gas switching valve 114 are based on an abnormality caused by fuel clogging related to the regenerative burner 4. Although the example which closes all was demonstrated, it is not necessarily limited to this, Various forms can be considered. That is, according to the burner body of the regenerative burner in which at least one of the fuel pressure in the piping path and the pressure of the combustion air in the piping path is equal to or lower than a predetermined lower limit pressure value based on the abnormal signal sent from the determination unit 140 In order to close at least the fuel switching valve, the valve closing signal may be sent from the signal sending unit 160c in the valve closing signal sending unit 160.

  In this embodiment, an example of a heating furnace in which two pairs of regenerative burners are arranged has been described. However, the present invention is not necessarily limited to this, and a heating furnace in which one or more pairs of regenerative burners are arranged is provided. The subject of the present invention.

1, 2, 3, 4 Regenerative burner 1a, 2a, 3a, 4a Burner body 1b, 2b, 3b, 4b Regenerator 5 Heating furnace 11, 12, 13, 14, 25, 30, 61, 62, 63, 64 , 75, 101, 102, 103, 104, 115 Piping 21, 22, 23, 24 Fuel switching valve 26 Fuel zone cutoff valve 27 Combustion flow rate adjustment valve 28 Fuel flow meter 29 Fuel tank 31 N ₂ purge valve 32 N ₂ tank 41 , 42, 43, 44, 81, 82, 83, 84 Pressure guiding tube 51, 52, 53, 54, 91, 92, 93, 94 Pressure switch (PS)
71, 72, 73, 74 Combustion air switching valve 77 Combustion air flow rate adjustment valve 78 Combustion air flow meter 79 Combustion air tank 111, 112, 113, 114 Exhaust gas switching valve 117 Exhaust gas flow rate control valve 118 Exhaust gas flow meter 119 Exhaust gas tank 121, 122, 123, 124, 131, 132, 133, 134, 141 Signal line 140 Judgment unit 142 Warning alarm unit 150 Heating furnace combustion monitoring device 160 Valve closing signal sending unit 160a, 160b, 160c, 160d, 160e Signal sending unit 170 Combustion control system L Length of pressure tube d Diameter of pressure tube

Claims (3)

A heat storage unit that has a heat storage function in the vicinity of the burner body, switches the direction of gas passing through the heat storage unit at predetermined time intervals based on a predetermined sequence, and continues combustion while alternately performing heat storage and combustion A combustion monitoring device for a heating furnace in which a pair of burners is disposed,
The heat storage type burner is disposed so as to correspond to the piping path between the burner body and the fuel switching valve and the piping path between the heat storage portion of each heat storage type burner and the combustion air switching valve, and the predetermined First and second lower limit pressure switches that are set to operate (ON) only during the combustion mode based on the sequence of (1) and to be inactive (OFF) during the heat storage mode;
Applicable when the pressure of fuel in the piping path corresponding to the first and second pressure switches with lower limit in the ON state and the pressure of combustion air in the piping path are equal to or lower than a predetermined lower limit pressure value. A lower limit pressure value detection signal is transmitted from the pressure switch, and the lower limit pressure value detection signal is input, and it is determined that a lower limit pressure value detection signal is transmitted from at least one of the pressure switches. In the case, a determination unit for sending an abnormal signal;
A warning issuing unit for issuing a warning based on the abnormal signal sent from the determination unit;
A combustion monitoring apparatus for a heating furnace, comprising: A heat storage unit that has a heat storage function in the vicinity of the burner body, switches the direction of gas passing through the heat storage unit at predetermined time intervals based on a predetermined sequence, and continues combustion while alternately performing heat storage and combustion A combustion monitoring method for a heating furnace in which a pair of burners is disposed,
The piping path between the burner body of each regenerative burner and the fuel switching valve and the piping path between the heat storage section of each regenerative burner and the combustion air switching valve operate only in the combustion mode based on the predetermined sequence. (ON) and first and second lower limit pressure switches with a lower limit set so as to be inactive (OFF) during the heat storage mode, respectively.
Applicable when the pressure of fuel in the piping path corresponding to the first and second pressure switches with lower limit in the ON state and the pressure of combustion air in the piping path are equal to or lower than a predetermined lower limit pressure value. A lower limit pressure value detection signal is transmitted from the pressure switch, and the lower limit pressure value detection signal is input to a determination unit, and the determination unit receives a lower limit pressure value detection signal from at least one of the pressure switches. Is determined to have been transmitted, an abnormal signal transmission step of transmitting an abnormal signal from the determination unit,
Based on the abnormal signal sent in this abnormal signal sending step, a warning issuing step for issuing a warning from the warning issuing unit,
A combustion monitoring method for a heating furnace, comprising: A combustion monitoring device for a heating furnace according to claim 1,
According to the burner body of the regenerative burner in which at least one of the pressure of the fuel in the piping path and the pressure of the combustion air in the piping path is equal to or lower than a predetermined lower limit pressure value based on the abnormal signal sent from the determination unit A valve closing signal sending unit for sending a valve closing signal for closing at least the fuel switching valve;
A combustion control system for a heating furnace, comprising:

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