JP5831026B2 - Boiler system - Google Patents

Description

  The present invention provides a first vapor pressure measuring means for measuring the vapor pressure of the steam collecting portion, a second vapor pressure measuring means as a spare thereof, and a first vapor pressure measuring means based on signals output from both measuring means. And a failure determination means for determining whether or not is a failure.

  The following Patent Document 1 includes a plurality of boilers, a vapor pressure sensor and a vapor pressure switch for measuring the vapor pressure of a steam collecting portion of the boiler, the value of the vapor pressure measured by the vapor pressure sensor, and the vapor pressure When it is determined that an abnormality has occurred in a boiler system that determines that an abnormality has occurred in the vapor pressure sensor or the vapor pressure switch when the signal output from the switch contradicts From the centralized control (number control) that controls the combustion amount of each boiler based on the steam pressure of the steam collecting part, the distributed control that controls the combustion amount for each boiler using the pressure detection device provided in each boiler ( A boiler system for switching to (local control) is disclosed. According to this boiler system, for example, an abnormal situation in which the combustion of all the boilers can be prevented and stable steam supply can be achieved.

JP 2007-192435 A

  However, in the boiler system described in Patent Document 1, if the value of the vapor pressure measured by the vapor pressure sensor contradicts the presence or absence of the signal output from the vapor pressure switch, the vapor pressure sensor or the vapor pressure switch is immediately It is determined that an abnormality (failure) has occurred. For this reason, there is a risk that it is determined that the failure is excessive (more than necessary) including the case where there is no problem in actual use.

  The present invention provides a first vapor pressure measuring means for measuring the vapor pressure of the steam collecting portion, a second vapor pressure measuring means as a spare thereof, and a first vapor pressure measuring means based on signals output from both measuring means. It is an object of the present invention to provide a boiler system capable of suppressing the first vapor pressure measurement unit from being determined to be excessively faulty in a boiler system including a failure determination unit that determines whether or not a failure occurs.

  The present invention includes one or a plurality of boilers that perform combustion, a steam collecting unit that collects steam generated in the boiler, and a first vapor pressure measuring unit that measures a vapor pressure inside the steam collecting unit, Provided as a reserve for the first vapor pressure measuring means, measuring the vapor pressure inside the vapor collecting portion, and when the measured vapor pressure is out of the second pressure range having a predetermined upper threshold and lower threshold Second vapor pressure measuring means for switching presence / absence of signal output, and based on the vapor pressure measured by the first vapor pressure measuring means so that the vapor pressure falls within a predetermined first pressure range, or the first A combustion amount control means for controlling the combustion amount so that the steam pressure inside the steam collecting portion falls within the second pressure range based on the presence or absence of a signal output from the two steam pressure measuring means; and the first steam Measured by pressure measuring means And a failure determination unit that determines whether or not the first vapor pressure measurement unit is malfunctioning based on the presence or absence of a signal output from the vapor pressure and the second vapor pressure measurement unit. The failure determination means includes a signal from the second vapor pressure measurement means that the vapor pressure measured by the first vapor pressure measurement means exceeds a failure upper limit threshold that is higher than the upper limit threshold of the second pressure range. When the presence or absence of the output indicates that the vapor pressure is below the upper limit threshold of the second pressure range, and the vapor pressure measured by the first vapor pressure measuring means is the lower limit of the second pressure range When the failure lower limit threshold value lower than the threshold value is below and the output of the signal from the second vapor pressure measuring means indicates that the vapor pressure exceeds the lower limit threshold value of the second pressure range, First vapor pressure measuring means About boiler system determines that failure.

  Further, failure prediction notification means for notifying a failure prediction of the first vapor pressure measurement means, vapor pressure measured by the first vapor pressure measurement means, and presence / absence of a signal output from the second vapor pressure measurement means And a notification control unit that controls the failure prediction notification unit based on the vapor pressure measured by the first vapor pressure measurement unit from an upper limit threshold value of the second pressure range. It is higher than a prediction upper limit threshold that is higher than the failure upper limit threshold, and the presence or absence of a signal output from the second vapor pressure measuring means indicates that the vapor pressure is lower than the upper limit threshold of the second pressure range. And the vapor pressure measured by the first vapor pressure measuring means is lower than a lower prediction threshold value lower than a lower threshold value of the second pressure range and higher than the failure lower threshold value, and the second Vapor pressure When the presence or absence of a signal output from the fixing means indicates that the vapor pressure exceeds the lower limit threshold of the second pressure range, the failure is notified so as to notify the prediction of the failure of the first vapor pressure measuring means. It is preferable to control the prediction notification means.

  According to the present invention, the first vapor pressure measuring means for measuring the vapor pressure of the steam collecting section, the preliminary second vapor pressure measuring means, and the first vapor pressure based on the signals output from both measuring means. In a boiler system including a failure determination unit that determines whether or not the measurement unit is faulty, it is possible to provide a boiler system that can suppress the first vapor pressure measurement unit from being determined to be excessively failed.

It is a figure showing an outline of boiler system 1 concerning an embodiment of the present invention. It is a graph which shows the change of the steam pressure inside the steam header 6. It is a schematic diagram for demonstrating the various threshold values which concern on vapor pressure. It is a flowchart which shows operation | movement of the boiler system 1 which concerns on embodiment.

  Hereinafter, with reference to FIG. 1, the boiler system 1 which concerns on embodiment of this invention is demonstrated. FIG. 1 is a diagram showing an outline of a boiler system 1 according to an embodiment of the present invention.

  As shown in FIG. 1, the boiler system 1 of the present embodiment includes a boiler group 2 including a plurality (three) of boilers 20, and a steam header 6 as a steam collecting unit that collects steam generated in the boiler 20. And a vapor pressure sensor 7 as a first vapor pressure measurement means, a vapor pressure switch 8 as a second vapor pressure measurement means, a number control unit 4, and a failure prediction notification unit 50 as a failure prediction notification means. .

The boiler system 1 of the present embodiment is capable of supplying the steam generated by the boiler group 2 to the steam use facility 18 operated by steam through the steam header 6.
The load required in the boiler system 1 (required load) is substituted by the steam pressure (physical quantity) inside the steam header 6 measured by the steam pressure sensor 7 when controlling the number of units. The boiler system 1 calculates the evaporation amount corresponding to the consumed steam amount of the steam using facility 18 based on the steam pressure.

  The boiler 20 includes a boiler main body 21 in which combustion is performed, a local control unit 25 that controls the combustion position (combustion state) of each boiler 20, and a local vapor pressure measurement unit 27 that measures the vapor pressure inside each boiler 20. Have.

The local control unit 25 can control each boiler 20 and change the combustion position (combustion state) according to the required load. The local control unit 25 controls each boiler 20 based on the number control signal from the number control unit 4 at the time of unit control, and directly controls the boiler 20 at the time of local control.
In the present embodiment, each boiler 20 constituting the boiler group 2 is a four-position control boiler having the same configuration (for example, the combustion position is the same). The boiler 20 can control combustion at a combustion stop position, a low combustion position, a middle combustion position, and a high combustion position.

  For example, the local vapor pressure measurement unit 27 includes a vapor pressure sensor and a vapor pressure switch or only a vapor pressure switch, and measures the vapor pressure inside each boiler 20. The local vapor pressure measurement unit 27 measures the vapor pressure used when performing local control of each boiler 20.

  Each boiler 20 is electrically connected to the number control unit 4 via the signal line 15 and the signal line 16. The local control unit 25 is a signal used by the number control unit 4 at the time of the number control, and outputs a signal such as a load required for the boiler 20 to the number control unit 4 via the signal line 15.

  When the number control is performed, the local control unit 25 shifts the combustion position to the lower side (to the combustion stop position) when the steam pressure inside the steam header 6 measured by the steam pressure sensor 7 becomes higher. The combustion of each boiler 20 is reduced so that the amount of evaporation is reduced, while when the vapor pressure inside the steam header 6 decreases, the combustion position is shifted to the higher side to increase the amount of evaporation. Control the position.

  When local control is performed, the local control unit 25 shifts the combustion position to the lower side (combustion stop position) when the vapor pressure inside the boiler 20 measured by the local vapor pressure measurement unit 27 increases. The combustion of each boiler 20 is reduced so that the amount of evaporation is reduced, while when the vapor pressure inside the boiler 20 becomes low, the combustion position is shifted to the higher side to increase the amount of evaporation. Control the position.

  The upstream side of the steam header 6 is connected to the boiler group 2 (each boiler 20) via a steam pipe 11. The downstream side of the steam header 6 is connected to the steam use facility 18 via the steam pipe 12. The steam header 6 collects and stores the steam generated in the boiler group 2 to adjust the pressure difference and pressure fluctuation between the boilers 20, and supplies the steam whose pressure is adjusted to the steam using equipment 18. It is like that.

  The vapor pressure sensor 7 is electrically connected to an input unit 4 </ b> A (described later) of the number control unit 4 through a signal line 13. The vapor pressure sensor 7 measures the vapor pressure inside the vapor header 6 and outputs a signal related to the measured vapor pressure (vapor pressure signal) to the number control unit 4 via the signal line 13.

  The vapor pressure switch 8 is electrically connected to the input unit 4 </ b> A of the number control unit 4 via the signal line 14. The vapor pressure switch 8 is provided as a spare for the vapor pressure sensor 7 and measures the vapor pressure inside the vapor header 6. The vapor pressure switch 8 switches the presence / absence of signal output when the measured vapor pressure deviates from a second pressure range K2w (see FIG. 2) having a predetermined upper limit threshold K2u and lower limit threshold K2d. Specifically, when the vapor pressure switch 8 goes out of the second pressure range K2w and goes from the OFF state to the ON state, the vapor pressure switch 8 outputs an ON signal, while when the vapor pressure switch 8 goes out of the second pressure range K2w and goes from the ON state to the OFF state. , Do not output ON signal.

  The failure prediction notification unit 50 notifies the prediction of the failure of the vapor pressure sensor 7. The failure prediction notification unit 50 includes, for example, a light emitting unit and an audio output unit as a configuration for reporting, and can emit light from the light emitting unit and output an alarm sound from the audio output unit.

  The number control unit 4 is electrically connected to each boiler 20 via the signal line 15 and the signal line 16. The number control unit 4 controls the number of each boiler 20 so that the boiler 20 is operated with high boiler efficiency (combustion efficiency). In addition, when local control is performed on each boiler 20, the number control by the number control unit 4 is not performed.

  The number control unit 4 includes an input unit 4A, a calculation unit 4B, a database 4D, and an output unit 4E. The number control unit 4 calculates the required combustion amount of the boiler group 2 and the combustion state of each boiler 20 corresponding to the required combustion amount in the calculation unit 4B based on a signal such as a required load input from the input unit 4A. The number control signal is output from the output unit 4E to the local control unit 25 of each boiler 20. Thereby, the number control part 4 controls the combustion quantity of each boiler 20, and performs the number control of the boiler group 2. FIG.

The input unit 4 </ b> A is connected to the vapor pressure sensor 7 through a signal line 13 and is connected to the vapor pressure switch 8 through a signal line 14. A signal (vapor pressure signal) related to the vapor pressure (first vapor pressure) P <b> 1 inside the vapor header 6 measured by the vapor pressure sensor 7 is input to the input unit 4 </ b> A via the signal line 13. In addition, an ON signal output from the vapor pressure switch 8 is input via the signal line 14.
The input unit 4 </ b> A is connected to each boiler 20 by a signal line 15. For example, information signals such as the combustion state of each boiler 20 and the number of boilers 20 that are burning are input to the input unit 4 </ b> A via the signal line 15.

  In the database 4D, for example, the required combustion amount of the boiler group 2 for accommodating the first steam pressure P1 inside the steam header 6 measured by the steam pressure sensor 7 within a predetermined first pressure range K1w (see FIG. 2). Information such as various thresholds described later is stored.

  The calculation unit 4B performs a predetermined calculation related to the setting of the combustion amount of the boiler 20. Specifically, the calculation unit 4B reads a control program stored in a storage medium (not shown) (for example, a ROM (Read Only Memory)), executes the control program, and outputs a vapor pressure signal from the vapor pressure sensor 7. Based on the above, the first steam pressure P1 inside the steam header 6 is calculated. In addition, the calculation unit 4B acquires the necessary combustion amount for keeping the vapor pressure within the predetermined first pressure range K1w by associating the first vapor pressure P1 with the database 4D.

  In addition, the calculation unit 4B determines whether or not the load is required when each boiler 20 is shifted to another combustion position based on the information on the operation state of each boiler 20 input from the input unit 4A. The combustion control signal is calculated based on the selection of another combustion position for ensuring the total evaporation amount that can satisfy the required evaporation amount corresponding to the above, the result, etc., and the combustion control signal via the output unit 4E Are output to each boiler 20. The combustion control signal includes the number of boilers that are burning, the combustion state (combustion amount) of the boiler, and the like.

  The output unit 4 </ b> E is connected to each boiler 20 by the signal line 16. The output unit 4E outputs the combustion control signal calculated by the calculation unit 4B to each boiler 20.

  As shown in FIGS. 2 and 3, the following threshold values are set in the boiler system of the present embodiment. Each threshold is set by the administrator, and each set threshold is stored in the database 4D of the number control unit 4 and is referred to by the calculation unit 4B. FIG. 2 is a graph showing changes in the steam pressure inside the steam header 6. FIG. 3 is a schematic diagram for explaining various threshold values related to the vapor pressure.

(1) As shown in FIG. 2, the first pressure range K <b> 1 w is such that the unit control unit 4 stores the vapor pressure inside the vapor header 6 based on the first vapor pressure P <b> 1 measured by the vapor pressure sensor 7. This is the range. The upper limit threshold value K1u is a threshold value indicating the upper limit of the first pressure range K1w. The lower limit threshold value K1d is a threshold value indicating the lower limit of the first pressure range K1w.

(2) As shown in FIGS. 2 and 3, the upper limit threshold K2u of the second pressure range K2w is such that the vapor pressure switch 8 changes from the ON state to the OFF state (the ON signal is output from the state where the ON signal is output). Vapor pressure threshold. The lower limit threshold value K2d of the second pressure range K2w is a threshold value of the vapor pressure at which the vapor pressure switch 8 changes from the OFF state to the ON state (the ON signal is output from the state where the ON signal is not output). The lower limit threshold K2d is lower than the upper limit threshold K2u by the differential value (the same size as the second pressure range K2w).

(3) As shown in FIG. 3, the failure upper limit threshold K3u is a threshold that is higher by ΔK3u than the upper limit threshold K2u of the second pressure range K2w. The failure upper limit threshold K3u is equal to or lower than the lower limit threshold K1d of the first pressure range K1w. The failure lower limit threshold K3d is a threshold that is lower by ΔK3d than the lower limit threshold K2d of the second pressure range K2w. The failure upper limit threshold K3u and the failure lower limit threshold K3d are used for determination of a failure of the vapor pressure sensor 7. ΔK3u and ΔK3d may be the same or different.

(4) As shown in FIG. 3, the prediction upper limit threshold K4u is a threshold that is higher by ΔK4u than the upper limit threshold K2u of the second pressure range K2w. ΔK4u is smaller than ΔK3u. That is, the prediction upper limit threshold K4u is lower than the failure upper limit threshold K3u. The prediction lower limit threshold K4d is a threshold lower by ΔK4d than the lower limit threshold K2d of the second pressure range K2w. ΔK4d is smaller than ΔK3d. That is, the prediction lower limit threshold K4d is higher than the failure lower limit threshold K3d. ΔK4u and ΔK4d may be the same or different. The prediction upper limit threshold value K4u and the prediction lower limit threshold value K4d are used to notify the prediction of the failure of the vapor pressure sensor 7.

  The reason why the failure upper limit threshold K3u, the failure lower limit threshold K3d, the prediction upper limit threshold K4u, and the prediction lower limit threshold K4d are used is as follows. The vapor pressure sensor 7, the vapor pressure switch 8, the calculation unit 4 </ b> B of the number control unit 4, and the like have various factors that reduce the measurement accuracy, and these various factors change with time and also with the environmental temperature. Further, there is a measurement timing shift (a signal output timing shift) between the vapor pressure sensor 7 and the vapor pressure switch 8. Due to these causes, the first vapor pressure P1 measured by the vapor pressure sensor 7 and the second vapor pressure P2 measured by the vapor pressure switch 8 (that is, the presence or absence of an ON signal) can be deviated from the set values. There is sex. Accordingly, if the upper limit threshold K2u and the lower limit threshold K2d of the second pressure range K2w are used without using the failure upper limit threshold K3u, the failure lower limit threshold K3d, the prediction upper limit threshold K4u, and the prediction lower limit threshold K4d, the vapor pressure sensor 7 fails. May be determined excessively. The reason is to suppress such a phenomenon.

  The calculation unit 4B will be further described in detail. The number control unit 4 includes a combustion amount control unit 41 as a combustion amount control unit, a failure determination unit 42 as a failure determination unit, a notification control unit 43 as a notification control unit, a switch determination unit 44, and a threshold determination unit. 45.

  Based on the first vapor pressure P1 measured by the vapor pressure sensor 7, the combustion amount control unit 41 is configured so that the vapor pressure inside the vapor header 6 falls within a predetermined first pressure range K1w (see FIG. 2). The combustion amount of each of the plurality of boilers 20 is controlled.

  The failure determination unit 42 determines whether or not the vapor pressure sensor 7 is in failure based on the first vapor pressure P1 measured by the vapor pressure sensor 7 and the presence or absence of an ON signal output from the vapor pressure switch 8. . Specifically, the failure determination unit 42 determines whether the first steam pressure P1 measured by the steam pressure sensor 7 exceeds the failure upper limit threshold K3u and whether the ON signal is output from the steam pressure switch 8 When the pressure P2 indicates that it is below the upper limit threshold K2u of the second pressure range K2w, and when the first vapor pressure P1 measured by the vapor pressure sensor 7 is below the failure lower limit threshold K3d, and the vapor pressure switch When the presence or absence of the ON signal output from 8 indicates that the second vapor pressure P2 exceeds the lower limit threshold K2d of the second pressure range K2w, it is determined that the vapor pressure sensor 7 is in failure.

  The notification control unit 43 controls the failure prediction notification unit 50 based on the first vapor pressure P1 measured by the vapor pressure sensor 7 and the presence / absence of an ON signal output from the vapor pressure switch 8. Specifically, the notification control unit 43 determines that the first vapor pressure P1 measured by the vapor pressure sensor 7 does not exceed the failure upper limit threshold K3u, exceeds the prediction upper limit threshold K4u, and the ON signal from the vapor pressure switch 8 When the presence / absence of output indicates that the second vapor pressure P2 is below the upper limit threshold K2u of the second pressure range K2w, and the first vapor pressure P1 measured by the vapor pressure sensor 7 is the failure lower limit threshold K3d. Is below the prediction lower limit threshold K4d, and the presence or absence of the ON signal output from the steam pressure switch 8 indicates that the second steam pressure P2 exceeds the lower limit threshold K2d of the second pressure range K2w. In addition, the failure prediction notification unit 50 is controlled so as to predict and notify the failure of the vapor pressure sensor 7.

  The switch determination unit 44 determines whether or not the ON signal output from the vapor pressure switch 8 is input to the input unit 4 </ b> A of the number control unit 4.

  The threshold value determination unit 45 compares the first vapor pressure P1 measured by the vapor pressure sensor 7 with the above-described various threshold values (failure upper limit threshold K3u, failure lower limit threshold K3d, prediction upper limit threshold K4u, prediction lower limit threshold K4d). Determine the relationship.

  Next, control for determining failure of the vapor pressure sensor 7 in the boiler system 1 of the present embodiment will be described with reference to FIG. FIG. 4 is a flowchart showing the operation of the boiler system 1 according to the embodiment.

  As shown in FIG. 4, in step ST <b> 1, the switch determination unit 44 determines whether or not the ON signal output from the vapor pressure switch 8 is input to the input unit 4 </ b> A of the number control unit 4. When the ON signal is input to the input unit 4A of the number control unit 4 (YES), the process proceeds to step ST2. On the other hand, when the ON signal is not input to the input unit 4A of the number control unit 4 (NO), the process proceeds to step ST3.

  In step ST2, the threshold determination unit 45 determines whether or not the vapor pressure (first vapor pressure) P1 measured by the vapor pressure sensor 7 exceeds the failure upper limit threshold K3u. If the first vapor pressure P1 exceeds the failure upper limit threshold K3u (YES), the process proceeds to step ST4. On the other hand, if the first vapor pressure P1 does not exceed the failure upper limit threshold K3u (NO), the process proceeds to step ST6.

  In step ST4, an ON signal is input to the input unit 4A of the number control unit 4 (the vapor pressure (second vapor pressure) P2 measured by the vapor pressure switch 8 is at least the upper threshold value of the second pressure range K2w). Despite being below K2u), the first vapor pressure P1 exceeds the failure upper limit threshold K3u (see ★ 11 and ☆ 13 in case 1 shown in FIG. 3). That is, the first vapor pressure P1 and the second vapor pressure P2 are inconsistent with each other over the difference ΔK3u between the failure upper limit threshold K3u and the upper limit threshold K2u of the second pressure range K2w. Therefore, the failure determination unit 42 determines that the vapor pressure sensor 7 is in failure.

  A typical example of actual change in vapor pressure in this case will be described. The vapor pressure curve indicating the actual vapor pressure P0 shown in FIG. 2 is within the upper limit threshold K1u and the lower limit threshold K1d of the first pressure range K1w in the normal state. However, at a certain point in time, it is assumed that the vapor pressure sensor 7 has failed and the first vapor pressure P1 measured by the vapor pressure sensor 7 continues to be measured at a vapor pressure higher than the upper threshold K1u (this state) The line indicating the first vapor pressure P1 is indicated by a broken line in FIG. In that case, in order to reduce an excessive vapor pressure, the combustion of all the boilers 20 constituting the boiler group 2 is stopped. As a result, the actual vapor pressure P0 gradually decreases and eventually falls below the lower limit threshold K2d of the second pressure range K2w. Thereby, the situation of step ST4 is formed. Since the situation in which combustion of all the boilers 20 is stopped is a particularly undesirable situation in the boiler system 1, it is very useful to be able to determine the failure of the vapor pressure sensor 7 in this situation.

After step ST4, in step ST5, failure determination unit 42 shifts the combustion control of boiler 20 from the unit control to the local control. Thereafter, the process ends.
In addition, when the administrator of the boiler system 1 repairs the failure of the vapor pressure sensor 7, the number control unit 4 may perform processing so that the number control is performed again.

When it is determined in step ST2 that the first vapor pressure P1 does not exceed the failure upper limit threshold K3u, the threshold determination unit 45 in step ST6 determines the vapor pressure (first vapor) measured by the vapor pressure sensor 7. Pressure) It is determined whether P1 exceeds the prediction upper limit threshold value K4u. When the first vapor pressure P1 exceeds the prediction upper limit threshold K4u (YES), the process proceeds to step ST7.
On the other hand, when the first vapor pressure P1 does not exceed the prediction upper limit threshold K4u in step ST2 (NO), the risk of failure of the vapor pressure sensor 7 is low. Therefore, the process returns to step ST1, and the unit control is continued.

In step ST7, the contradiction between the first vapor pressure P1 and the second vapor pressure P2 is large (see ★ 11 and ☆ 14 in case 1 shown in FIG. 2), and failure of the vapor pressure sensor 7 is expected. It is in a state. Therefore, it is desirable to notify the administrator of the boiler system 1 of the prediction of the failure of the vapor pressure sensor 7. Therefore, the notification control unit 43 controls the failure prediction notification unit 50 so as to notify the prediction of the failure of the vapor pressure sensor 7. For example, the notification control unit 43 controls the failure prediction notification unit 50 so that the light emitting unit emits light and an alarm sound is output from the sound output unit. Thereby, the administrator of the boiler system 1 can prepare for the failure of the vapor pressure sensor 7. This preparation includes, for example, replacement of the vapor pressure sensor 7 or the vapor pressure switch 8, and review of set values of various threshold values (failure upper limit threshold K3u, failure lower limit threshold K3d, prediction upper limit threshold K4u, prediction lower limit threshold K4d). .
Further, the process returns to step ST1, and the unit control is continued.

  When it is determined in step ST1 that the ON signal is not input to the input unit 4A (NO), in step ST3, the threshold determination unit 45 determines the vapor pressure (first vapor pressure) measured by the vapor pressure sensor 7. ) Determine whether P1 is below the failure lower limit threshold K3d. If the first vapor pressure P1 is lower than the failure lower limit threshold K3d (YES), the process proceeds to step ST8. On the other hand, when the first vapor pressure P1 does not fall below the failure lower limit threshold K3d (NO), the process proceeds to step ST9.

  In step ST8, the ON signal is not input to the input unit 4A of the number control unit 4 (the vapor pressure (second vapor pressure) P2 measured by the vapor pressure switch 8 is at least a lower threshold of the second pressure range K2w). Despite being above K2d), the first vapor pressure P1 is below the failure lower limit threshold K3d (see ★ 21 and ☆ 23 in case 2 shown in FIG. 3). That is, the first vapor pressure P1 and the second vapor pressure P2 are inconsistent with each other by a difference ΔK3d or more between the failure lower limit threshold K3d and the lower limit threshold K2d of the second pressure range K2w. Therefore, the failure determination unit 42 determines that the vapor pressure sensor 7 is in failure.

  After step ST8, in step ST5, failure determination unit 42 shifts the combustion control of boiler 20 from the unit control to the local control. Thereafter, the process ends.

If it is determined in step ST3 that the first vapor pressure P1 does not fall below the failure lower limit threshold K3d (NO), in step ST9, the threshold determination unit 45 determines the vapor pressure (first value) measured by the vapor pressure sensor 7. It is determined whether or not (vapor pressure) P1 falls below the prediction lower limit threshold K4d. If the first vapor pressure P1 is lower than the prediction lower limit threshold K4d (YES), the process proceeds to step ST10.
On the other hand, when the first vapor pressure P1 does not fall below the prediction lower limit threshold K4d (NO), the risk that the vapor pressure sensor 7 will fail is low. Therefore, the process returns to step ST1, and the unit control is continued.

  In step ST10, the contradiction between the first vapor pressure P1 and the second vapor pressure P2 is large (see ★ 21 and ☆ 24 in case 2 shown in FIG. 2), and failure of the vapor pressure sensor 7 is expected. It is in a state. Therefore, it is desirable to notify the administrator of the boiler system 1 of the prediction of the failure of the vapor pressure sensor 7. Therefore, the notification control unit 43 controls the failure prediction notification unit 50 so as to notify the prediction of the failure of the vapor pressure sensor 7. Further, the process returns to step ST1, and the unit control is continued.

According to the boiler system 1 of this embodiment, the following effects are produced, for example.
In the present embodiment, the failure determination unit 42 determines that the first vapor pressure P1 measured by the vapor pressure sensor 7 exceeds the failure upper limit threshold K3u that is higher than the upper limit threshold K2u of the second pressure range K2w, and the vapor pressure switch The first vapor pressure measured by the vapor pressure sensor 7 when the presence or absence of the output of the ON signal from 8 indicates that the second vapor pressure P2 is below the upper limit threshold K2u of the second pressure range K2w P1 falls below a failure lower limit threshold K3d lower than the lower limit threshold K2d of the second pressure range K2w, and whether or not the ON signal is output from the steam pressure switch 8 indicates that the second steam pressure P2 is the lower limit of the second pressure range K2w. When it indicates that the threshold value K2d is exceeded, it is determined that the vapor pressure sensor 7 is malfunctioning.

  Therefore, according to the present embodiment, even if the value of the first vapor pressure P1 measured by the vapor pressure sensor 7 and the presence / absence of the signal output from the vapor pressure switch 8 are somewhat inconsistent, the vapor pressure sensor is immediately It is determined that the vapor pressure sensor 7 is in failure only when there is a significant contradiction between the two without determining that 7 is in failure. Therefore, it is possible to suppress the vapor pressure sensor 7 from being determined to be in excess (more than necessary) including a case where there is no problem in actual use.

  In the present embodiment, the notification control unit 43 determines that the first vapor pressure P1 measured by the vapor pressure sensor 7 does not exceed the failure upper limit threshold K3u and is higher than the upper limit threshold K2u of the second pressure range K2w. Moreover, it exceeds the prediction upper limit threshold K4u lower than the failure upper limit threshold K3u, and the presence or absence of the ON signal output from the vapor pressure switch 8 is such that the second vapor pressure P2 is lower than the upper limit threshold K2u of the second pressure range K2w. And the first vapor pressure P1 measured by the vapor pressure sensor 7 does not fall below the failure lower limit threshold K3d, is lower than the lower limit threshold K2d of the second pressure range K2w, and less than the failure lower limit threshold K3d. The lower threshold K2d when the second vapor pressure P2 is lower than the higher prediction lower threshold K4d and the second vapor pressure P2 is in the second pressure range K2w. When indicating that above the controls PFA notification unit 50 to notify the prediction of a failure of the vapor pressure sensor 7.

  Therefore, according to the present embodiment, the contradiction between the first vapor pressure P1 measured by the vapor pressure sensor 7 and the second vapor pressure P2 measured by the vapor pressure switch 8 is large, and the vapor pressure sensor 7 A state where a failure is expected can be detected. The failure prediction notification unit 50 can notify the administrator of the boiler system 1 of the failure prediction of the vapor pressure sensor 7.

As mentioned above, although preferred embodiment was described, this invention is not limited to embodiment mentioned above, It can implement with a various form.
For example, in the embodiment, the upper limit threshold K2u of the second pressure range K2w is the vapor pressure at which the vapor pressure switch 8 changes from the ON state to the OFF state (the ON signal is not output from the state where the ON signal is output). The lower limit threshold K2d of the second pressure range K2w is the vapor pressure switch 8 from the OFF state to the ON state (the ON signal is output from the state where the ON signal is not output). Although it is a threshold value, it is not limited to this. The upper limit threshold value K2u of the second pressure range K2w is a threshold value of the vapor pressure at which the vapor pressure switch 8 changes from the OFF state to the ON state (the ON signal is output from the state where the ON signal is not output). The lower limit threshold value K2d of the two pressure range K2w may be a threshold value of the vapor pressure at which the vapor pressure switch 8 changes from the ON state to the OFF state (the ON signal is not output from the state where the ON signal is output).

The upper limit threshold K1u and the lower limit threshold K1d of the first pressure range K1w are different in the embodiment, but may be the same (that is, the first pressure range K1w may not have a width).
The steam collecting unit is not limited to the steam header 6 that stores the collected steam, and may be, for example, a steam collecting pipe that simply collects steam.
The number of boilers in the boiler system may be one.

  In the embodiment, the combustion amount control unit 41 sets the combustion amount so that the steam pressure inside the steam header 6 falls within a predetermined second pressure range based on the presence or absence of a signal output from the steam pressure switch 8. Do not control. However, the combustion amount control unit 41 may control the combustion amount based on the presence or absence of a signal output from the steam pressure switch 8 so that the steam pressure inside the steam header 6 falls within a predetermined second pressure range. Good.

DESCRIPTION OF SYMBOLS 1 Boiler system 4 Unit control part 6 Steam header 7 Steam pressure sensor (1st steam pressure measuring means)
8 Vapor pressure switch (second vapor pressure measuring means)
20 Boiler 21 Boiler body 41 Combustion amount control unit (combustion amount control means)
42 Failure determination unit (failure determination means)
43 Notification Control Unit (Notification Control Unit)
50 Failure prediction notification unit (failure prediction notification means)
K1d lower limit threshold K1u upper limit threshold K1w first pressure range K2d lower limit threshold K2u upper limit threshold K2w second pressure range K3d failure lower limit threshold K3u failure upper limit threshold K4d prediction lower limit threshold K4u prediction upper limit threshold

Claims (2)

One or more boilers in which combustion takes place;
A steam collecting part for collecting steam generated in the boiler;
First vapor pressure measuring means for measuring a vapor pressure inside the vapor collecting portion;
Provided as a reserve for the first vapor pressure measuring means, measuring the vapor pressure inside the vapor collecting portion, and when the measured vapor pressure is out of the second pressure range having a predetermined upper threshold and lower threshold Second vapor pressure measuring means for switching presence / absence of signal output;
Based on the vapor pressure measured by the first vapor pressure measuring means, the vapor pressure falls within a predetermined first pressure range, or based on the presence or absence of a signal output from the second vapor pressure measuring means. A combustion amount control means for controlling the combustion amount so that the steam pressure inside the steam collecting portion falls within the second pressure range;
Failure determination for determining whether or not the first vapor pressure measuring means is out of order based on the presence or absence of a signal output from the vapor pressure measured by the first vapor pressure measuring means and the second vapor pressure measuring means A boiler system comprising means,
The failure determination means has a vapor pressure measured by the first vapor pressure measurement means that exceeds a failure upper limit threshold that is higher than an upper limit threshold of the second pressure range, and a signal from the second vapor pressure measurement means When the presence or absence of output indicates that the vapor pressure is below the upper threshold value of the second pressure range, and the vapor pressure measured by the first vapor pressure measuring means is the lower threshold value of the second pressure range Lower than the lower failure threshold value, and the presence or absence of a signal output from the second vapor pressure measuring means indicates that the vapor pressure exceeds the lower threshold value of the second pressure range. 1 Boiler system that determines that the vapor pressure measuring means is out of order. A failure prediction notification means for notifying a failure prediction of the first vapor pressure measurement means;
A notification control means for controlling the failure prediction notification means based on the presence or absence of a signal output from the vapor pressure measured by the first vapor pressure measurement means and the second vapor pressure measurement means;
The notification control means has a vapor pressure measured by the first vapor pressure measurement means that exceeds a prediction upper limit threshold that is higher than an upper limit threshold of the second pressure range and lower than the failure upper limit threshold, and the second When the presence or absence of a signal output from the vapor pressure measuring means indicates that the vapor pressure is below the upper threshold value of the second pressure range, and the vapor pressure measured by the first vapor pressure measuring means is The presence or absence of a signal output from the second vapor pressure measuring means is lower than a lower prediction threshold lower than the lower limit threshold of the second pressure range and higher than the failure lower limit threshold, and the vapor pressure is the second pressure. 2. The boiler system according to claim 1, wherein the failure prediction notification unit is controlled so as to notify a failure prediction of the first vapor pressure measurement unit when it indicates that the lower limit threshold of the range is exceeded.

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