JP2017138011A - Combustion control system, and combustion control method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a combustion control system capable of preventing excessive generation of exhaust gas from a boiler.SOLUTION: A combustion control system 300 comprises an exhaust gas amount detection section 31 for detecting an amount of exhaust gas discharged from a boiler 2. Thus, the combustion control system 300 can recognize the amount of the exhaust gas discharged from the boiler 2. The combustion control system 300 further comprises an energy amount adjustment section 34 for adjusting an amount of energy obtained in the boiler 2 using information on the amount of exhaust gas detected by the exhaust gas amount detection section 31. As a result, the energy amount adjustment section 34 can adjust an amount of energy obtained by the boiler 2 according to a situation of the generation of exhaust gas. Thus, the amount of energy can be adjusted by the energy amount adjustment section 34 so that the generation of the exhaust gas can be suppressed when the amount of exhaust gas become excessive.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a combustion control system and a combustion control method.

  Conventionally, what is described in patent document 1 is known as a boiler which burns fuel. In this boiler, biomass fuel, which is an organic resource derived from animals and plants excluding fossil resources, is burned in a combustion furnace. In this boiler, various controls are performed based on the results of various sensors in the system.

JP 2005-226930 A

  Here, as a result of intensive studies, the present inventors have found that the amount of exhaust gas increases as the amount of water contained in the fuel increases (see, for example, FIG. 4). The reason why the amount of exhaust gas increases when the amount of water in the fuel is large is that the water in the fuel that is not useful as energy evaporates, resulting in excess exhaust gas. Further, as shown in FIG. 3, the lower heating value tends to decrease as the amount of water contained in the fuel increases. Therefore, when a desired amount of heat is to be obtained, if the amount of water contained in the fuel is large, it is necessary to increase the amount of fuel input. As described above, when the amount of water contained in the fuel is large, the amount of fuel input increases and the exhaust gas amount ratio also increases, resulting in a problem that the amount of exhaust gas generated in the boiler becomes excessive. When the amount of exhaust gas is excessive, wear of the exhaust gas system is likely to occur, and there is a problem that equipment damage due to abnormal wear occurs.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a combustion control system capable of suppressing an excessive amount of exhaust gas generated in a boiler.

  In order to solve the above problems, a combustion control system according to the present invention is a combustion control system that controls combustion of a boiler, and includes an exhaust gas amount detection unit that detects the amount of exhaust gas discharged from the boiler, and an exhaust gas amount detection unit. An energy amount adjusting unit that adjusts the amount of energy obtained by the boiler using information on the detected amount of exhaust gas.

  The combustion control system according to the present invention includes an exhaust gas amount detection unit that detects the amount of exhaust gas discharged from a boiler. Thereby, the combustion control system can grasp | ascertain how much exhaust gas is discharged | emitted from a boiler. In addition, the combustion control system includes an energy amount adjustment unit that adjusts the amount of energy obtained by the boiler using information on the amount of exhaust gas detected by the exhaust gas amount detection unit. Therefore, the energy amount adjustment unit can adjust the amount of energy obtained by the boiler according to the generation state of the exhaust gas amount. Thereby, when the amount of exhaust gas becomes excessive, the energy amount can be adjusted by the energy amount adjustment unit so that the generation of the amount of exhaust gas can be suppressed. As described above, it is possible to suppress the exhaust gas generated in the boiler from becoming excessive.

  In the combustion control system according to the present invention, the exhaust gas amount detection unit may be configured by a measuring device that measures the flow rate of the exhaust gas. With such a configuration, the exhaust gas amount detection unit can directly detect the exhaust gas amount generated in the boiler, and can obtain an accurate exhaust gas amount.

  In the combustion control system according to the present invention, the exhaust gas amount detection unit may detect the exhaust gas amount based on the operation information of the exhaust unit provided on the exhaust gas flow channel through which the exhaust gas of the boiler flows. With such a configuration, the amount of exhaust gas generated in the boiler can be indirectly detected. Therefore, the exhaust gas amount detection unit that detects indirectly when the one that is directly detected fails can function as a backup. In addition, the exhaust gas amount detection unit may detect the exhaust gas amount indirectly at normal times, and when the exhaust gas detection unit breaks down, the method may be switched to a method of directly detecting the exhaust gas amount.

  In the combustion control system according to the present invention, the energy amount adjustment unit may decrease the amount of energy obtained by the boiler when it is determined that the amount of exhaust gas is large. With such a configuration, when the amount of exhaust gas is large, the energy amount adjustment unit reduces the amount of energy, so that the exhaust gas generated in the boiler can be reduced.

  In the combustion control system according to the present invention, the energy amount adjustment unit determines the energy amount obtained by the boiler based on the determination unit that determines whether the exhaust gas amount exceeds a predetermined threshold and the determination result of the determination unit. And an adjustment unit that reduces only a fixed amount. With such a configuration, since the determination unit performs determination based on a predetermined threshold, it can be easily determined that the amount of exhaust gas has increased. In addition, since the adjustment unit decreases the energy amount by a predetermined amount, the calculation load can be reduced as compared with a case where control is performed to obtain the decrease amount by a single calculation.

  The combustion control method according to the present invention is a combustion control method for controlling the combustion of a boiler, the exhaust gas amount detecting step for detecting the exhaust gas amount discharged from the boiler, and the information of the exhaust gas amount detected in the exhaust gas amount detecting step. And an energy amount adjusting step for adjusting the amount of energy obtained by the boiler.

  According to the combustion control method of the present invention, it is possible to obtain the same operations and effects as those of the above-described combustion control system.

  According to the present invention, it is possible to prevent the exhaust gas generated in the boiler from becoming excessive.

FIG. 1 is a block diagram of a boiler system including a combustion control system according to the present embodiment. FIG. 2 is a flowchart illustrating a control process executed by the combustion control system according to the present embodiment. FIG. 3 is a graph showing the relationship between the lower heating value and the total moisture. FIG. 4 is a graph showing the relationship between the total moisture and the exhaust gas amount ratio.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. In the following description, the same or corresponding elements are denoted by the same reference numerals, and redundant description is omitted.

  FIG. 1 is a block diagram of a boiler system including a combustion control system according to the present embodiment. As shown in FIG. 1, the boiler system 1 includes a boiler facility 100, a boiler operation control unit 200, and a combustion control system 300.

  The boiler facility 100 is a facility that processes a boiler 2 that burns fuel and exhaust gas discharged from the boiler 2. Specifically, the boiler facility 100 includes a boiler 2, a water supply channel 3, a steam channel 4, an exhaust gas channel 6, an exhaust unit 7, and an exhaust cylinder 8. The boiler 2 is a device for burning supplied fuel. The kind of boiler 2 is not specifically limited, You may employ | adopt all kinds of boilers. For example, a circulating fluidized bed boiler, a pulverized coal boiler, a stoker boiler, or the like may be employed as the boiler 2.

  Connected to the boiler 2 are a water supply channel 3 for supplying water to the boiler 2 and a steam channel 4 for discharging steam generated by heating the water supplied by the boiler 2. Has been. When the heat quantity of water supplied from the feed water flow path 3 is “G” and the heat quantity of steam discharged from the steam flow path 4 is “H”, the heat output (%) of the boiler is “H−”. G ".

  The boiler 2 is connected to an exhaust gas passage 6 through which exhaust gas generated from the boiler 2 flows. Further, on the exhaust gas channel 6, an exhaust unit 7 is provided for circulating the exhaust gas flowing through the exhaust gas channel 6 to the downstream side. In this embodiment, the exhaust part 7 is comprised by the induction ventilator which ventilates exhaust gas. The exhaust section 7 is set to have a driving strength based on a current value of an induction fan control device to be described later. An end portion on the downstream side of the exhaust gas passage 6 is connected to the exhaust cylinder 8. The exhaust cylinder 8 is a chimney-like device for exhausting the exhaust gas discharged from the boiler 2 to the outside of the boiler equipment 100.

  The boiler operation control unit 200 includes a fuel supply unit 21, a fuel supply channel 22, an air supply unit 23, an air supply channel 24, a heat input information transmission path 26, an LHV information transmission path 27, and a fuel amount. An information transmission path 28 and a theoretical air amount information transmission path 29 are provided.

  The fuel supply unit 21 is a device that supplies fuel to the boiler 2 via the fuel supply channel 22. The fuel supply unit 21 is configured by a pump or the like, for example. In addition, as a fuel which the fuel supply part 21 supplies, the biomass fuel which is an organic resource derived from animals and plants except a fossil resource may be employ | adopted, for example. Moreover, in this embodiment, biomass fuel with much moisture content may be employ | adopted. The air supply unit 23 is a device that supplies combustion air to the boiler 2 via the air supply flow path 24. The air supply part 23 may be comprised by a forced ventilator etc., for example.

  A heat input information transmission path 26 and an LHV information transmission path 27 are connected to a fuel supply system constituted by the fuel supply unit 21 and the fuel supply flow path 22. The heat input amount information transmission path 26 transmits information related to heat input (amount of energy) set by the combustion control system 300 described later to the fuel supply system. The LHV information transmission path 27 transmits information related to the lower heating value (LHV) to the fuel supply system. The LHV information is a value indicating how much heat is required. In the fuel supply system, the load on the boiler is set using information from the heat input amount information transmission path 26 and the LHV information transmission path 27, and the fuel is adjusted accordingly.

  A fuel amount information transmission path 28 and a theoretical air amount information transmission path 29 for setting the air amount are connected to the air supply system. The fuel amount information transmission path 28 transmits information related to the amount of fuel supplied to the boiler 2 to the air supply system. The theoretical air amount information transmission path 29 transmits information related to the theoretical air amount, which is the amount of air necessary for combustion, to the air supply system. In the air supply system, air is adjusted according to the supplied fuel using information from the fuel amount information transmission path 28 and the theoretical air amount information transmission path 29.

  The combustion control system 300 is a system that controls the combustion of the boiler 2. The combustion control system 300 includes an exhaust gas amount detection unit 31 and a controller 32. The exhaust gas amount detector 31 is means for detecting the amount of exhaust gas discharged from the boiler 2. The controller 32 is a unit having a function of adjusting the energy amount of the boiler 2 based on the exhaust gas amount detected by the exhaust gas amount detection unit 31, and is configured by, for example, a CPU, a ROM, a RAM, and the like.

  The exhaust gas amount detection unit 31 has a function of detecting the amount of exhaust gas discharged from the boiler 2. Specifically, the exhaust gas amount detection unit 31 includes an exhaust gas flow meter 41 that functions as a measuring device that measures the flow rate of exhaust gas. The exhaust gas flow meter 41 is provided in the exhaust cylinder 8 and can measure the flow rate of the exhaust gas discharged from the exhaust cylinder 8. The exhaust gas flow meter 41 transmits the measured exhaust gas flow rate as detection information to the controller 32 via the transmission path 51.

  The exhaust gas amount detection unit 31 includes an IDF current value detection unit 42 that detects the exhaust gas amount based on operation information of the exhaust unit 7 provided on the exhaust gas flow path 6 through which the exhaust gas of the boiler 2 flows. The IDF current value detection unit 42 acquires the operation information of the exhaust unit 7 by detecting the current value of the induction fan (IDF) functioning as the exhaust unit 7 and detects the amount of exhaust gas based on the operation information. be able to. For example, when the IDF current value exceeds the upper limit, the exhaust gas amount detection unit 31 can recognize that the exhaust gas amount is excessive because the IDF is in an overload operation state. The IDF current value detection unit 42 transmits the operation information of the exhaust unit 7 as detection information to the controller 32 via the transmission path 52.

  The controller 32 includes a detection information acquisition unit 33 and an energy amount adjustment unit 34. The detection information acquisition unit 33 has a function of acquiring information regarding the amount of exhaust gas transmitted from the exhaust gas flow meter 41 and information regarding the amount of exhaust gas transmitted from the IDF current value detection unit 42. The energy amount adjustment unit 34 has a function of adjusting the amount of energy obtained by the boiler 2 using information on the amount of exhaust gas detected by the exhaust gas amount detection unit 31 and acquired by the detection information acquisition unit 33.

  The energy amount adjustment unit 34 includes a determination unit 36 and an adjustment unit 37. The determination unit 36 has a function of determining whether or not the amount of exhaust gas is large based on the information regarding the amount of exhaust gas acquired by the detection information acquisition unit 33. More specifically, the determination unit 36 has a function of determining whether or not the exhaust gas amount exceeds a predetermined threshold based on the information related to the exhaust gas amount acquired by the detection information acquisition unit 33. The determination unit 36 performs determination based on the IDF current value detected by the IDF current value detection unit 42 and the exhaust gas amount detected by the exhaust gas flow meter 41. For example, the determination unit 36 determines whether or not the IDF current value and the amount of exhaust gas have exceeded the upper limit (threshold value) in the past (for example, an average value for several minutes may be compared with the threshold value). It may be determined whether the amount is large. As described above, the determination using the two parameters of the IDF current value and the exhaust gas amount has an advantage that the system can be operated even at the time of a single failure as compared with the case of determination using one parameter. In addition, the determination method by the determination part 36 is not specifically limited, You may determine whether there are many exhaust gas amounts by using whether the detected IDF electric current value and exhaust gas amount exceed the upper limit.

  The adjustment unit 37 has a function of adjusting the amount of energy (heat input) obtained by the boiler 2 based on the determination result in the determination unit 36. For example, the adjustment unit 37 has a function of reducing the amount of energy obtained by the boiler 2 when the determination unit 36 determines that the amount of exhaust gas is large. The adjustment unit 37 has a function of reducing the amount of energy obtained by the boiler 2 by a predetermined amount based on the determination result of the determination unit 36. For example, the adjustment unit 37 may adjust the energy amount by changing the value of the boiler master (BMCR). The adjustment unit 37 may reduce the boiler master by 1% when the amount of exhaust gas is large. However, the reduction amount of the boiler master may not be 1%, and a larger value or a smaller value may be set. The boiler master means that combustion is performed at the design limit of the boiler 2 when the boiler master that controls the load of the boiler is 100%.

  Next, a combustion control method according to this embodiment will be described with reference to FIG.

  FIG. 2 is a flowchart illustrating a control process executed by the combustion control system 300. As shown in FIG. 2, when the combustion control process is started, the adjustment unit 37 of the energy amount adjustment unit 34 of the controller 32 sets the boiler master (BMCR) to a predetermined value (step S100). In FIG. 2, the predetermined value is indicated as “X%”, but X is an arbitrary number. Next, the IDF current value detection unit 42 detects the IDF current value and transmits it to the detection information acquisition unit 33 of the controller 32, and the exhaust gas flow meter 41 detects the amount of exhaust gas and sends it to the detection information acquisition unit 33 of the controller 32. Transmit (exhaust gas amount detection step). Accordingly, the determination unit 36 of the controller 32 determines whether or not the past IDF current value and exhaust gas amount (average value for the past 10 minutes) have exceeded the upper limit (step S110). In S110, when the determination unit 36 determines that each value does not exceed the upper limit, the adjustment unit 37 maintains the boiler master as X% (step S120), and repeats the process of S100 again.

  On the other hand, if the determination unit 36 determines in S110 that each value exceeds the upper limit, the adjustment unit 37 automatically lowers the boiler master by 1% (step S130: energy amount adjustment step). As a result, the boiler master becomes “(X−1)%”. After a predetermined time (here, 10 minutes) has elapsed, the determination unit 36 of the controller 32 determines whether or not the past ID current value and exhaust gas amount (average value for the past 10 minutes) have exceeded the upper limit (step S140). . In S140, when the determination unit 36 determines that each value does not exceed the upper limit, the adjustment unit 37 maintains the boiler master at (X-1)% (step S150), and after 140 minutes, S140. Repeat the process again.

  On the other hand, when the determination unit 36 determines in S140 that each value exceeds the upper limit, the adjustment unit 37 automatically lowers the boiler master by 1% (step S160: energy amount adjustment step). Thereby, a boiler master will be "((X-1) -1)%". When the process of S160 ends, the process is executed again from S100. At this time, the value of “((X−1) −1)%” at the time of S160 becomes the value of “X%” of S100 of the next process.

  Next, operations and effects of the combustion control system 300 and the combustion control method according to the present embodiment will be described.

  Here, as a result of intensive studies, the present inventors have found that the amount of exhaust gas increases as the amount of water contained in the fuel increases. For example, as shown in FIG. 4, the exhaust gas amount ratio (vertical axis) increases as the moisture content (horizontal axis) of the fuel increases. The reason why the amount of exhaust gas increases when the amount of water in the fuel is large is that the water in the fuel that is not useful as energy evaporates, resulting in excess exhaust gas. Further, as shown in FIG. 3, the lower the calorific value (horizontal axis) tends to decrease as the amount of water contained in the fuel (vertical axis) increases. Thus, if the lower heating value is reduced, even if a predetermined amount of fuel is added, if the amount of water is large, the desired amount of heat cannot be obtained. Therefore, when a desired amount of heat is to be obtained, if the amount of water contained in the fuel is large, it is necessary to increase the amount of fuel input. As described above, when the amount of water contained in the fuel is large, the amount of fuel input increases and the exhaust gas amount ratio also increases, resulting in a problem that the amount of exhaust gas generated in the boiler becomes excessive. When the amount of exhaust gas is excessive, wear of the exhaust gas system is likely to occur, and there is a problem that equipment damage due to abnormal wear occurs.

  Therefore, the combustion control system 300 according to the present embodiment includes an exhaust gas amount detection unit 31 that detects the amount of exhaust gas discharged from the boiler 2. Thereby, the combustion control system 300 can grasp | ascertain how much exhaust gas is discharged | emitted from the boiler 2. FIG. In addition, the combustion control system 300 includes an energy amount adjustment unit 34 that adjusts the amount of energy obtained by the boiler 2 using information on the amount of exhaust gas detected by the exhaust gas amount detection unit 31. Therefore, the energy amount adjusting unit 34 can adjust the amount of energy obtained by the boiler 2 according to the generation state of the exhaust gas amount. Thereby, when the amount of exhaust gas becomes excessive, the amount of energy can be adjusted by the energy amount adjustment unit 34 so that the generation of the amount of exhaust gas can be suppressed. As described above, it is possible to suppress the exhaust gas generated in the boiler 2 from becoming excessive.

  In the combustion control system 300 according to the present embodiment, the exhaust gas amount detection unit 31 includes an exhaust gas flow meter (measuring device) 41 that measures the flow rate of exhaust gas. With such a configuration, the exhaust gas amount detection unit 31 can directly detect the exhaust gas amount generated in the boiler 2 and can obtain an accurate exhaust gas amount.

  In the combustion control system 300 according to the present embodiment, the exhaust gas amount detection unit 31 detects the exhaust gas amount based on the operation information of the exhaust unit 7 provided on the exhaust gas passage 6 through which the exhaust gas of the boiler 2 flows. . With such a configuration, the amount of exhaust gas generated in the boiler can be indirectly detected. Therefore, the exhaust gas amount detection unit 31 that detects indirectly when something directly detected fails can function as a backup. In addition, when the exhaust gas amount detection unit 31 detects the exhaust gas amount indirectly at the normal time and the exhaust gas amount detection unit 31 breaks down, it may be switched to a method of directly detecting the exhaust gas amount as a backup. In particular, in this embodiment, an IDF current value detection unit 42 is employed as the exhaust gas amount detection unit 31. Thus, by detecting the amount of exhaust gas based on the IDF current value, there is a merit that the system can be operated even at the time of a single failure.

  In the combustion control system 300 according to the present embodiment, the energy amount adjustment unit 34 reduces the amount of energy obtained in the boiler 2 when it is determined that the amount of exhaust gas is large. With such a configuration, when the amount of exhaust gas is large, the energy amount adjustment unit 34 can reduce the amount of energy, thereby reducing the exhaust gas generated in the boiler 2.

  In the combustion control system 300 according to the present embodiment, the energy amount adjustment unit 34 determines whether or not the exhaust gas amount has exceeded a predetermined threshold and the boiler 2 based on the determination result of the determination unit 36. An adjustment unit 37 that reduces the amount of energy obtained by a predetermined amount. With such a configuration, the determination unit 36 makes a determination based on a predetermined threshold value, so that it can be easily determined that the amount of exhaust gas has increased. In addition, since the adjustment unit 37 reduces the energy amount by a predetermined amount, the calculation load can be reduced as compared with a case where control is performed to obtain the decrease amount by a single calculation.

  The combustion control method according to the present embodiment is a combustion control method for controlling the combustion of the boiler 2, and an exhaust gas amount detection step for detecting the amount of exhaust gas discharged from the boiler 2 and an exhaust gas detected in the exhaust gas amount detection step. An energy amount adjusting step of adjusting the amount of energy obtained by the boiler 2 using the amount information.

  According to the combustion control method according to the present embodiment, the same actions and effects as those of the above-described combustion control system 300 can be obtained.

  The present invention is not limited to the embodiment described above.

  For example, the control process by the controller 32 is not limited to the flowchart shown in FIG. 2, and may be changed as appropriate within the scope of the present invention. For example, in the process of FIG. 2, only the point that the boiler master decreases is mentioned, but control for increasing the boiler master may be added or performed separately. For example, the boiler master may be increased by satisfying a predetermined condition in S120, S150, and the like. Moreover, when the boiler master reaches near the lower limit, the boiler master may be prevented from lowering. Moreover, you may perform control processing which increases a boiler master. In addition, the amount of exhaust gas may be suppressed by performing control such as constant air ratio operation.

  In the above-described embodiment, the energy amount adjustment unit adjusts the energy amount by automatic control. However, the energy amount adjustment unit may be configured by an interface or the like that can accept an operator's input. For example, the operator may confirm the state of the amount of exhaust gas on a monitor or the like and perform an operation so as to adjust the amount of energy of the boiler based on the situation.

  DESCRIPTION OF SYMBOLS 2 ... Boiler, 6 ... Exhaust gas flow path, 7 ... Exhaust part, 31 ... Exhaust gas amount detection part, 34 ... Energy amount adjustment part, 36 ... Determination part, 37 ... Adjustment part, 41 ... Exhaust gas flowmeter (measuring device), 300 ... combustion control system.

Claims (6)

A combustion control system for controlling the combustion of a boiler,
An exhaust gas amount detector for detecting the amount of exhaust gas discharged from the boiler;
A combustion control system comprising: an energy amount adjusting unit that adjusts an energy amount obtained by the boiler using information on the exhaust gas amount detected by the exhaust gas amount detecting unit.   The combustion control system according to claim 1, wherein the exhaust gas amount detection unit includes a measurement device that measures a flow rate of the exhaust gas.   The combustion control system according to claim 1 or 2, wherein the exhaust gas amount detection unit detects the exhaust gas amount based on operation information of an exhaust unit provided on an exhaust gas flow path through which the exhaust gas of the boiler flows.   The combustion control system according to any one of claims 1 to 3, wherein the energy amount adjustment unit decreases the energy amount obtained by the boiler when it is determined that the exhaust gas amount is large. The energy amount adjustment unit includes:
A determination unit for determining whether or not the exhaust gas amount exceeds a predetermined threshold;
The combustion control system according to any one of claims 1 to 4, further comprising: an adjustment unit that reduces an amount of energy obtained by the boiler by a predetermined amount based on a determination result of the determination unit. A combustion control method for controlling combustion of a boiler,
An exhaust gas amount detection step for detecting the amount of exhaust gas discharged from the boiler;
A combustion control method comprising: an energy amount adjustment step of adjusting an energy amount obtained by the boiler using information on the exhaust gas amount detected in the exhaust gas amount detection step.

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