Combustion monitoring device and combustion monitoring program

Abstract

To enable a user to grasp a malfunction of a combustion device by an index other than flame activeness.SOLUTION: A combustion monitoring device 20 includes: an information acquisition part 21A for acquiring a plurality of sets of a flow rate of fuel of a flow rate of fuel supplied to a burner of a combustion device and a flow rate of air, and a ratio value indicating a ratio of the flow rate of the air to a theoretical amount of air; and an information processing part 21B for executing processing to display, on a display 24, a graph for plotting the plurality of sets acquired by the information acquisition part 21A in a coordinate system with the flow rate of the fuel as a first axis and the ratio value as a second axis.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a combustion monitoring device and a combustion monitoring program for monitoring a combustion device. [Background technology]

[0002] Patent Document 1 discloses a technology for monitoring the flame activity of a burner (ultraviolet intensity in Patent Document 1) for each of a number of subsequences that make up a combustion sequence (Patent Document 1 refers to "pilot ignition (trial)," "pilot only," "main ignition," and "main stable"). With this technology, if the flame activity of the burner being monitored deviates from a predetermined range set for each subsequence, it is determined that a malfunction has occurred in the combustion device. By checking the results of this determination, the user can determine that a malfunction has occurred in the combustion device. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2019-60573 Summary of the Invention [Problem to be solved by the invention]

[0004] The technology described in Patent Document 1 focuses on the flame activity of the burner, but there are cases where it is desirable to identify malfunctions in a combustion device based on indicators other than the flame activity, because, for example, there may be types of malfunctions that cannot be identified by monitoring the flame activity.

[0005] The present invention has been made in view of the above points, and an object of the present invention is to allow a user to recognize malfunctions in a combustion device using an index other than the flame activity. [Means for solving the problem]

[0006] In order to solve the above problems, the combustion monitoring device of the present invention includes an information acquisition unit that acquires multiple pairs of fuel flow rates among the fuel and air flow rates supplied to a burner of a combustion device and ratio values ​​that indicate the ratio of the air flow rate to the theoretical air volume, and an information processing unit that executes processing to display on a display unit a graph in which the multiple pairs acquired by the information acquisition unit are plotted in a coordinate system in which the fuel flow rate is the first axis and the ratio value is the second axis.

[0007] The graph may show a normal range that can be taken by a combination of the fuel flow rate and the air ratio when the combustion device is normal.

[0008] The information processing unit may identify the normal range based on a plurality of pairs of the fuel flow rate and the ratio value acquired by the information acquisition unit when the combustion device is normal.

[0009] The information processing unit may plot the plurality of sets in the coordinate system using a plurality of figures, each of which may be semi-transparent so that when the figures are plotted overlapping each other, the color of the overlapping portions becomes darker. The information processing unit determines that the combustion device is not normal when a predetermined number or more of the plurality of groups are outside a predetermined normal range, and outputs an output to that effect.

[0010] The information processing unit may estimate that a different type of malfunction is occurring in the combustion device depending on the tendency of a group that falls outside the normal range among the multiple groups to deviate from the normal range, and output the estimated malfunction.

[0011] The information processing unit may infer that a malfunction in which the combustion efficiency of the combustion device is decreasing is occurring when the deviation tendency of the set that is outside the normal range is a tendency toward a larger fuel flow rate along the first axis from the normal range.

[0012] If the deviation tendency of the set that is outside the normal range is a tendency to deviate from the normal range along the second axis, the information processing unit may estimate that a malfunction has occurred due to a change in the state of equipment of the combustion device or a misadjustment of the equipment.

[0013] The information processing unit may output information suggesting a method of dealing with the estimated malfunction.

[0014] The combustion monitoring program of the present invention causes a computer to execute an information acquisition step of acquiring multiple pairs of fuel flow rates among the fuel and air flow rates supplied to a burner of a combustion device and ratio values ​​indicating the ratio of the air flow rate to the theoretical air volume, and an information processing step of executing a process of displaying on a display unit a graph in which the multiple pairs acquired by the information acquisition step are plotted in a coordinate system in which the fuel flow rate is the first axis and the ratio value is the second axis. [Effects of the Invention]

[0015] According to the present invention, it is possible to allow a user to know malfunction of a combustion device by using an index other than the degree of flame activity. [Brief explanation of the drawings]

[0016] [Figure 1] FIG. 1 is a configuration diagram of a heating system having a combustion monitoring device according to an embodiment of the present invention. [Figure 2] FIG. 2 is a flowchart of a combustion sequence executed by the combustion control device. [Figure 3] FIG. 3 is a hardware configuration diagram of the combustion monitoring device. [Figure 4] FIG. 4 is a partial configuration diagram of the combustion monitoring device. [Figure 5] FIG. 5 is a flowchart of the information acquisition process. [Figure 6] FIG. 6 is a diagram showing an example of the configuration of a teaching data table. [Figure 7] FIG. 7 is a diagram showing an example of the configuration of the comparison data table. [Figure 8] FIG. 8 is a flowchart of the normal range identification process. [Figure 9] FIG. 9 is a graph in which the teaching data is plotted on a coordinate system in which the X axis represents the flow rate of fuel gas and the Y axis represents the air ratio. [Figure 10] FIG. 10 is a graph in which the normal range is added to the graph in FIG. [Figure 11] FIG. 11 is a graph of another example of FIG. [Figure 12] FIG. 12 is a graph in which the comparative data is plotted on a coordinate system in which the X-axis represents the flow rate of fuel gas and the Y-axis represents the air ratio. [Figure 13] FIG. 13 is a flowchart of the graph display process. [Figure 14] FIG. 14 is a graph in which other comparative data is plotted on a coordinate system in which the X axis represents the flow rate of fuel gas and the Y axis represents the air ratio. [Figure 15] FIG. 15 is a graph in which other comparative data is plotted on a coordinate system in which the X axis represents the flow rate of fuel gas and the Y axis represents the air ratio. [Figure 16] FIG. 16 is a diagram for explaining a diagram when plotting the comparison data. DETAILED DESCRIPTION OF THE INVENTION

[0017] Hereinafter, an embodiment of the present invention and its modifications will be described with reference to the drawings.

[0018] (Embodiment) As shown in FIG. 1 , a combustion monitoring device 20 according to one embodiment of the present invention is used in a combustion system 10. The combustion monitoring device 20 monitors the flow rate of fuel gas and the flow rate of air supplied to a main burner 42 (described below) of the combustion device 30 in order to allow the user to properly understand malfunctions (at least the presence or absence of a malfunction and its cause) of the combustion device 30 (described below). Here, "malfunction" refers to a mild malfunction in which the combustion device 30 is still able to perform heating, before a severe malfunction occurs, such as a flame failure that makes combustion impossible. Malfunctions can also be considered a sign of a severe malfunction. If the malfunction is left unchecked, a severe malfunction may occur.

[0019] In addition to the combustion monitoring device 20, the combustion system 10 is equipped with a combustion device 30 that performs combustion, a combustion control device 71 that controls the combustion device 30, and a temperature controller 75 that issues various instructions to the combustion control device 71. Below, the combustion device 30, combustion control device 71, and temperature controller 75 will be explained first, followed by an explanation of the combustion monitoring device 20.

[0020] The combustion device 30 includes a combustion facility 40, a fuel supply system 50, an air supply system 60, a control motor M, and an opening sensor MS.

[0021] The combustion equipment 40 burns fuel gas in a combustion chamber R. The combustion equipment 40 includes a combustion furnace 41 that forms the combustion chamber R, a main burner 42 that burns the fuel gas to heat the inside of the combustion chamber R, a pilot burner 43 that burns fuel to ignite the main burner 42, and an ignition device (igniter) 44 that ignites the pilot burner 43.

[0022] The combustion equipment 40 further includes a flame detector 45 that detects the flame activity of the main burner 42 and the pilot burner 43, and a temperature sensor 46 that detects the temperature inside the combustion chamber R. The flame activity is a measure of how actively the flame is generated, and is referred to here as the flame intensity. The flame detector 45 detects the intensity of electromagnetic waves (ultraviolet rays) emitted from the flame of the main burner 42 or the pilot burner 43 as the flame activity.

[0023] The fuel supply system 50 supplies fuel gas from the outside to the combustion equipment 40. The fuel supply system 50 includes a fuel flow path 51 through which the fuel gas supplied to the combustion equipment 40 flows. The fuel flow path 51 includes a main flow path 51A through which fuel gas is supplied from the outside, and a first flow path 51B and a second flow path 51C branched from the main flow path 51A. The first flow path 51B is connected to the main burner 42, and the second flow path 51C is connected to the pilot burner 43.

[0024] The fuel supply system 50 further includes main valves 54A and 54B provided in the first flow path 51B and pilot valves 54C and 54D provided in the second flow path 51C. The main valves 54A and 54B open and close the first flow path 51B. The pilot valves 54C and 54D open and close the second flow path 51C. The fuel supply system 50 further includes a damper 55 provided in the main flow path 51A for adjusting the fuel flow rate, and a fuel flow meter 56 for detecting the flow rate of the fuel gas flowing through the first flow path 51B, i.e., supplied to the main burner 42.

[0025] The air supply system 60 supplies air to the combustion equipment 40. The air supply system 60 includes an air flow path 61 that supplies air to the main burner 42 of the combustion equipment 40, and a blower 62 that flows air through the air flow path 61. The air supply system 60 further includes a damper 65 for adjusting the air flow rate provided in the air flow path 61, and an air flow meter 66 that detects the flow rate of air flowing through the air flow path 61, i.e., the air that is supplied to the main burner 42.

[0026] The dampers 55 and 65 for adjusting the fuel or air flow rate are operated by a control motor M to control the opening degree of the fuel flow path 51 (first flow path 51B) and the air flow path 61. The dampers 55 and 65 operate in conjunction with each other via a linkage mechanism. This links the opening degrees of the dampers 55 and 65. The dampers 55 and 65 may also be configured to be linked by other structures. For example, the damper 65 may be a pressure equalizing valve into which the air pressure of the air flow path 61 of the air supply system 60 is introduced. This damper 65 operates to equalize the air pressure in the air flow path 61 and the fuel pressure in the first flow path 51B of the fuel flow path 51.

[0027] The opening degrees of the dampers 55 and 65 work together to maintain a desired air-fuel ratio, which is the ratio of fuel to air supplied to the main burner 42. The opening degrees of the dampers 55 and 65 adjust the amounts of fuel and air supplied to the main burner 42, thereby adjusting the flame activity of each burner, and as a result, the heating temperature at which the combustion chamber R is heated.

[0028] The control motor M is provided with an opening sensor MS that detects the opening of the dampers 55 and 65 by detecting the rotation angle of the rotary shaft, etc. The opening detected by the opening sensor MS is used as a feedback value when feedback-controlling the control motor M to control the opening of the dampers 55 and 65.

[0029] The combustion control device 71 includes various types of computers, such as a PLC (Programmable Logic Controller) and a personal computer. The combustion control device 71 is also called a burner controller. To heat the inside of the combustion chamber R, the combustion control device 71 controls the combustion device 30 according to a predetermined combustion sequence. As shown in FIG. 2, the combustion sequence includes subsequences such as "pre-purge" (step S1), "pilot ignition" (step S2), "pilot only" (step S3), "main ignition" (step S4), "main stabilization" (step S5), and "steady combustion" (step S6). At the start of the combustion sequence, the valves 54A to 54D of the fuel supply system 50 are assumed to be closed.

[0030] In pre-barge, the combustion control device 71 drives the control motor M to control the damper 65 to a high opening position and operates the blower 62 of the air supply system 60. As a result, fresh air is blown into the combustion chamber R via the main burner 42, and fuel gas remaining in the combustion chamber R is discharged to the outside. Pre-barge is performed for a fixed period of time. When controlling the opening of the dampers 55 and 65, the combustion control device 71 feedback-controls the control motor M using the opening detected by the opening sensor MS as a feedback value (the same applies to the control of the opening hereinafter).

[0031] After the pre-barge, the combustion control device 71 controls the dampers 55 and 65 to the low opening position. Thereafter, the combustion control device 71 controls the pilot valves 54C and 54D of the fuel supply system 50 to the open state to start fuel supply to the pilot burner 43, and also operates the ignition device 44 to perform pilot ignition, which generates an ignition spark. This ignites the pilot burner 43. The combustion control device 71 detects ignition of the pilot burner 43 when the flame activity detected by the flame detector 45 exceeds a predetermined value. After this detection, the combustion control device 71 executes pilot-only, which stabilizes the flame of the pilot burner 43 by waiting for a predetermined period of time.

[0032] After pilot only, the combustion control device 71 controls the main valves 54A and 54B of the fuel supply system 50 to an open state, thereby executing main ignition to start fuel supply to the main burner 42. As a result, the main burner 42 is ignited using the flame of the pilot burner 43 as a pilot flame. After a certain period of time has passed since the main valves 54A and 54B were opened, the combustion control device 71 determines that main ignition has ended, closes the pilot valves 54C and 54D of the fuel supply system 50, and extinguishes the flame of the pilot burner 43. Thereafter, the combustion control device 71 executes main stabilization, waiting for a certain period of time to stabilize the flame of the main burner 42.

[0033] After the main combustion is stabilized, the combustion control device 71 transitions to steady combustion. The combustion chamber R is heated by steady combustion of the main burner 42. During steady combustion, the combustion control device 71 controls the flow rates of air and fuel to the main burner 42 by controlling the opening of dampers 55 and 65 via control motor M, thereby controlling the heat output (flame activity) of the main burner 42 (details will be described later). When steady combustion ends, the combustion control device 71 closes main valves 54A and 54B of the fuel supply system 50 to extinguish the flame of the main burner 42. Post-barge may be performed after steady combustion.

[0034] During the above-described series of combustion sequences, the combustion control device 71 monitors the flow rates of the fuel gas and air to the main burner 42 detected by the flow meter 56 or 66. Each flow rate is used as a control process value.

[0035] The combustion control device 71 stores a sequence number that indicates whether a combustion sequence is currently being executed and, if a combustion sequence is being executed, the current subsequence. For example, a state in which a combustion sequence is not being executed is assigned the sequence number "0." The subsequences pre-purge, pilot ignition, pilot only, main ignition, main stable, and steady combustion are assigned sequence numbers "1" through "6," respectively. The combustion control device 71 updates the sequence numbers it stores based on the start of a combustion sequence, a change in subsequence, etc.

[0036] Returning to FIG. 1 , the temperature controller 75 instructs the combustion control device 71 to start the combustion sequence and to end steady combustion (the timing of the end of the combustion sequence). Furthermore, the temperature controller 75 uses the temperature detected by the temperature sensor 46 as a feedback value to instruct the combustion control device 71 to maintain the temperature in the combustion chamber R at a target temperature. The temperature controller 75 instructs the flow rates of fuel and air during steady combustion based on the relationship between the feedback value and the target temperature. When instructing the fuel and air flow rates, the temperature controller 75 supplies the flow rates as target values ​​to the combustion control device 71. The combustion control device 71 derives a target opening from the supplied target values ​​and performs feedback control on the control motor M using the opening from the opening sensor MS as a feedback value so that the opening of each damper 55 and 65 becomes the target opening. Note that the combustion control device 71 may also control the target opening using feedback control using the flow rates of fuel gas and air to the main burner 42 detected by the flow meter 56 or 66 as feedback values.

[0037] The combustion monitoring device 20 in Fig. 1 is configured to include various types of computers, such as a personal computer. As shown in Fig. 3, the combustion monitoring device 20 includes a processor 21, such as a CPU (Central Processing Unit), a RAM (Random Access Memory) 22 that functions as the main memory of the processor 21, and a non-volatile storage device 23 that stores a combustion monitoring program executed by the processor 21. The storage device 23 also stores a teaching data table, a comparison data table, a combustion count value, and normal range data (details will be described later). The combustion monitoring device 20 further includes a display 24 that displays various screens, which will be described later, an operation device 25 that is operated by a user, and a communication module 26 that allows the processor 21 to communicate with the combustion control device 71 and the temperature controller 75.

[0038] In this embodiment, the processor 21 executes a combustion monitoring program stored in the storage device 23, thereby operating as an information acquisition unit 21A and an information processing unit 21B shown in FIG.

[0039] The information acquisition unit 21A functions as a data collector that periodically (e.g., every second) collects various data from the combustion control device 71, the temperature controller 75, and the like and stores the collected data in the storage device 23 together with the date and time. The date and time may be provided by the information acquisition unit 21A as the acquisition date and time of the various data, or may be provided by the combustion control device 71 as the date and time when the combustion control device 71, etc., acquired the various data. The information acquisition unit 21A acquires, in particular, the flow rates of fuel gas and air to the main burner 42 detected by the flowmeter 56 or 66 via the combustion control device 71. The information acquisition unit 21A acquires the ratio value indicating the ratio of the air flow rate to the theoretical air volume from the acquired flow rates. Hereinafter, this ratio value will be described as the air ratio; however, a value such as the air-fuel ratio that has a certain relationship with the ratio and can indirectly indicate the ratio may also be used as the ratio value.

[0040] The information acquisition unit 21A executes the information acquisition process shown in FIG. 5 as a process for acquiring the flow rates of fuel gas and air and the air ratio. The information acquisition unit 21A communicates with the combustion control device 71, monitors the sequence number stored in the combustion control device 71, and performs the process shown in FIG. 5 when it detects that the sequence number has changed from "4" (main ignition) to "5" (main stable). The information acquisition unit 21A further increments the combustion count value stored in the storage device 23 by 1 when the sequence number changes from "0" to "1." This counts the total number of executions of the combustion sequence since the start of operation of the combustion system 10, i.e., the total number of combustions. As another example, the information acquisition unit 21A may increment the combustion count value by 1 when the sequence number changes to "6" (steady combustion) to count the total number of combustions (the total number of combustions in which steady combustion has been performed). In this way, the combustion count value indicates the total number of combustions. The information acquisition process shown in FIG. 5 ends when the sequence number changes from "6" to "0."

[0041] 5, the information acquisition unit 21A waits until one of a plurality of predetermined timings in main stable or steady combustion arrives (step S11). The information acquisition unit 21A measures the elapsed time from the timing when the sequence number changes to "5," and when the measured elapsed time reaches one of the plurality of timings, determines that one of the plurality of timings has arrived.

[0042] When any of the above-mentioned multiple timings arrives (step S11; Yes), the information acquisition unit 21A extracts and acquires the flow rates of fuel gas and air to the main burner 42, detected by the flow meter 56 or 66 and supplied from the combustion control device 71, as flow rate data from the various data acquired periodically (step S12).

[0043] The information acquisition unit 21A acquires the flow rate Q of the fuel gas from the acquired flow rate data. fuel and air flow rate Q air Based on this, the air ratio R is calculated by the following formula (1) to obtain the air ratio R (step S13). fuel *10.7 is the theoretical air volume, and "10.7" is the coefficient when the fuel gas is city gas (13A). This means that theoretically, 1 m 3 The amount of air required to burn city gas (13A) is 10.7 m 3 "10.7" is changed depending on the type of fuel gas. R=Q air / (Q fuel *10.7)···(1)

[0044] The information acquisition unit 21A determines whether to use the acquired set of fuel gas flow rate and air ratio as teaching data for defining the normal range of these sets (details will be described later) (step S14). If the current combustion count value is equal to or less than a predetermined value, the information acquisition unit 21A determines the acquired set as teaching data. The predetermined value is set in advance as the number of combustions that ensures that the combustion system 10 (particularly the combustion device 30) still operates normally. Therefore, the teaching data becomes data for the set of fuel gas flow rate and air ratio when the combustion system 10 is normal.

[0045] If the information acquisition unit 21A uses the acquired set as teaching data (step S14; Yes), it stores the set in a teaching data table in the storage device 23 (step S15). In this case, the acquisition date and time and the number of combustions (combustion number count value) are also stored together with the set. The acquisition date and time may be the current date and time acquired by the information acquisition unit 21A by referring to a calendar unit or the like when the flow rate data is acquired, or may be the detection date and time of each flow rate supplied from the combustion control device 71 together with data such as the fuel gas flow rate.

[0046] As shown in FIG. 6, the teaching data table stores the flow rate of fuel gas, the air ratio at that flow rate, the acquisition date and time, and the number of combustions in association with one another.

[0047] If the current combustion count value exceeds a predetermined value, the information acquisition unit 21A determines that the acquired set is not to be used as teaching data, but rather as comparison data that is displayed and compared with a normal range based on the teaching data (step S14; No). In this case, the information acquisition unit 21A stores the set in a comparison data table provided in the storage device 23 (step S16). In this case, as in the above, the acquisition date and time and the number of combustions (combustion count value) are stored together with the set.

[0048] As shown in FIG. 7, the comparison data table stores the flow rate of fuel gas, the air ratio at that flow rate, the acquisition date and time, and the number of combustions in association with one another.

[0049] After step S15 or S16, the information acquiring unit 21A executes the process of step S11 again.

[0050] 4, the information processing unit 21B executes a normal range determination process based on the teaching data in the teaching data table to determine a normal range as a range of values ​​that the fuel gas flow rate and the air ratio at that fuel gas flow rate can take when the combustion system 10 (particularly the combustion device 30) is normal. This process is executed when a certain number of teaching data have been stored in the teaching data table.

[0051] The information processing unit 21B executes the process shown in Fig. 8 as the normal range identification process. In this process, the information processing unit 21B first reads out all teaching data recorded in the teaching data table, each of which is made up of a pair of a fuel gas flow rate and an air ratio associated with the fuel gas flow rate (step S21). The information processing unit 21B then identifies the normal range (see Fig. 10) based on all the read pairs (step S22).

[0052] The normal range is specified by any method. For example, the information processing unit 21B divides the fuel gas flow rate into certain sections, specifies a normal range of the air ratio for each section using kernel density estimation or the like, and connects the normal ranges of each section to define the overall normal range. If the number of teaching data used to specify the normal range is small, the information processing unit 21B may increase the number of teaching data by any method. As another example, the information processing unit 21B may generate a graph (see FIG. 9) in which all the read-out sets are plotted in a Cartesian coordinate system with the fuel flow rate on the X axis and the air ratio on the Y axis, and display the generated graph on the display 24. In this case, a user viewing the graph may operate the operation device 25 to specify the normal range on the display 24. The information processing unit 21B specifies the specified range as the normal range. Note that the number of plots in the graph in FIG. 9 is smaller than the actual number (the same applies to the other graphs).

[0053] FIG. 10 shows a graph in which normal ranges have been set. In FIG. 10, a first normal range S1 (a narrow range that traces the outside of the group of plots of teaching data) and a second normal range S2 (a range in which the threshold for determining normality is lower than that of the first normal range S1) are specified as normal ranges. In the examples of FIGS. 9 and 10, the air ratio is relatively high in the region R1 where the fuel gas flow rate is low. On the other hand, the air ratio in the region R2 where the fuel gas flow rate is high is within the range of 1.02 to 1.1, which is close to the ideal air ratio. In this embodiment, the device characteristics of the dampers 55 and 65 of the combustion device 30 and the characteristics of the linkage mechanism are adjusted so that the region R2 of the fuel gas flow rate with a good air ratio corresponds to the fuel gas flow rate region during steady combustion. The region R1 of the low fuel gas flow rate corresponds to the fuel gas flow rate region during main stability.

[0054] 9 and 11, the shape of the group of plots varies depending on the equipment characteristics of the combustion device 30 (particularly, the equipment characteristics of the dampers 55 and 65, the characteristics of the linkage mechanism, etc.) In FIGS. 9 and 11, the air ratio is high when the flow rate of fuel gas is low, but there are also cases where the air ratio is approximately constant regardless of the flow rate of fuel gas.

[0055] The information processing unit 21B records normal range data indicating the identified normal range in the storage device 23 (step S23).

[0056] The information processing unit 21B in Fig. 2 further plots at least some of all pairs of fuel gas flow rates and air ratios associated with the flow rates recorded in the comparison data table on the orthogonal coordinate system, and generates a graph (see Fig. 12) on which the pairs are plotted. The information processing unit 21B displays the generated graph on the display 24 together with the normal ranges S1 and S2 specified above.

[0057] For displaying the graph, the information processing unit 21B executes, for example, a graph display process shown in Fig. 13. This process is started at any timing (for example, when an instruction to display the graph is input to the operation device 25) after the normal range has been identified.

[0058] The information processing unit 21B first reads out, as the most recent comparison data, a pair corresponding to a date and time or a number of combustions within a period going back a certain time from the present or a certain number of times from the most frequent number of combustions, from among the pairs of fuel gas flow rates and air ratios corresponding to the flow rates recorded in the comparison data table (step S31). The information processing unit 21B generates a graph (FIGS. 12 and 14) in which the read-out most recent comparison data is plotted on the orthogonal coordinate system and the plotted comparison data (hereinafter also referred to as a comparison data plot) is superimposed on the normal range identified above (step S32). The information processing unit 21B causes the generated graph to be displayed on the display 24 (step S33).

[0059] The user looks at the graph displayed on the display 24 and compares the plotted comparative data plot with the normal range to determine whether a malfunction has occurred in the combustion device 30. If each set of points is outside the normal range S1 or S2 as shown in Figure 14, it can be determined that a malfunction has occurred in the combustion device 30. For example, it can be determined that a malfunction has occurred in the dampers 55 and 65 or the linkage mechanism (or pressure equalizing valve) of the combustion device 30, causing the flow ratio of fuel gas to air to be disrupted.

[0060] The type of malfunction may be inferred based on the tendency of deviation of the comparison data plot from the normal range, e.g., the tendency of the deviation. For example, as shown by arrow AR1 and the dotted circle at its end in FIG. 15, if the comparison data plot tends to deviate from the normal range along the X-axis toward a higher fuel gas flow rate (to the right of the graph), it can be determined that a malfunction has occurred, with the combustion efficiency of the combustion device decreasing due to an increased amount of combustion gas used. For example, the heat retention of the combustion chamber R may be poor. For example, as shown by arrows AR2 or A3 and the dotted circle at its end in FIG. 15, if the comparison data plot tends to deviate from the normal range along the Y-axis (up and down on the graph), it can be determined that a deterioration in the air-fuel ratio has occurred, and that a malfunction has occurred due to a change in the status of equipment in the combustion device 30 or an adjustment error in the equipment. The change in status includes a change in the status of equipment for feedback control, such as the dampers 55 and 65. The adjustment error in the equipment includes, for example, an adjustment error in the linkage mechanism for linking the opening of the dampers 55 and 65.

[0061] As described above, in this embodiment, the information acquisition unit 21A acquires multiple pairs (recent comparison data) of the fuel gas flow rate, which is the flow rate of fuel gas and the flow rate of air supplied to the main burner 42 of the combustion device 30, and the air ratio (ratio value), which indicates the ratio of the air flow rate to the theoretical air volume. The information processing unit 21B then executes processing to display on the display 24 a graph (see FIGS. 12, 14, and 15) in which the multiple pairs acquired by the information acquisition unit 21A are plotted on a coordinate system with the fuel gas flow rate on the X axis and the air ratio on the Y axis. This allows a user who checks the graph to determine whether a malfunction has occurred in the combustion device 30 by comparing the position of the plotted comparison data plot, particularly the normal ranges S1 and S2, in this case, that is, by comparing the position with the normal ranges S1 and S2. In particular, this allows the user to determine malfunctions that cannot be detected by monitoring the flame activity of the main burner 42, such as malfunctions in the dampers 55 and 65 or the linkage mechanism (or pressure equalizing valve) of the combustion device 30.

[0062] Alternatively, the normal range S2 may be set as a normal range in which there is a high possibility of an abnormality occurring, and the abnormality may be determined based on the number of plots out of the normal range S1 among the multiple comparison data plots. For example, the tendency of the deviation may be based on the normal range S1.

[0063] The information processing unit 21B plots each of the plurality of sets, which are the plurality of comparison data, on a coordinate system using a graphic (here, a circle). As shown in FIG. 16, each of the plotted graphics P (comparison data plots) is preferably semi-transparent so that the overlapping portions are darker in color when they are plotted together. This allows the user to see that the sets are concentrated in areas with darker colors, and if there is a darker color outside the normal range S1 or S2, for example, the user can understand that there is a high possibility that the malfunction has occurred. The distribution and average of the air ratio for each fuel gas flow rate can be understood by the shade of color.

[0064] The teaching data, comparison data, normal ranges, etc. may be divided according to the type and / or amount of workpieces heated in the combustion chamber R. For example, the type and / or amount of workpieces can be determined from the past operational performance of the combustion device 30. Therefore, each record constituting the teaching data table and comparison data table is divided by type and / or amount of workpieces based on the acquisition date and time or the number of combustions. The normal ranges may be determined and plotted separately for each data divided by type and / or amount of workpieces. By generating the graphs for each type and / or amount of workpieces, a more detailed understanding of malfunctions can be obtained. Furthermore, by dividing the comparison data into multiple groups along a timeline and generating graphs for each group, the deterioration of the combustion device over time can be understood. Furthermore, by dividing the graphs by the type and / or amount of workpieces, the progression of deterioration over time for each type and / or amount of workpieces can be understood.

[0065] (Variation) The configuration of the above embodiment can be modified as desired. Modifications are shown below as examples. At least some of the modifications can be combined with each other.

[0066] (Variation 1) The combustion device 30 may have any configuration. For example, the combustion device 30 may be of a type that has only the main burner 42 without the pilot burner 43. Alternatively, the combustion device 30 may be in a state in which the pilot burner 43 is always ignited. In this case, a flame detector for the main burner 42 and a flame detector for the pilot burner 43 may be provided.

[0067] (Variation 2) The normal ranges S1 and S2 do not have to be displayed on the graph. Even if there are no normal ranges, the position of the plotted set in the graph can allow the user to understand the malfunction of the combustion device 30. Although there may be only one normal range, by setting two stages of normal ranges as in the above embodiment, the user can easily understand the degree of signs of malfunction.

[0068] (Variation 3) The normal range may be set in advance according to the configuration of the combustion device 30, without relying on teaching data.

[0069] (Variation 4) The above sets adopted as teaching data may be limited to when the temperature of the combustion chamber R is high, etc. Furthermore, the above sets adopted as comparison data may only be those when the air ratio is high or when the air ratio is good. For example, sets plotted only in regions R1 and R2 of FIG. 9 may be plotted, and sets plotted between regions R1 and R2 may be omitted without being plotted. If a set adopted as teaching data or comparison data contains a sudden abnormal value, that set may be deleted without being adopted.

[0070] (Variation 5) When a predetermined number or more of the plurality of sets (comparison data) acquired by the information acquisition unit 11A are outside a predetermined normal range such as the normal range S1 or S2, the information processing unit 21B may determine that the combustion device 30 is not normal, i.e., malfunctioning, and output a message to that effect. For example, when generating the graph, the information processing unit 21B counts the number of sets (comparison data plots) plotted outside the normal range S1 or S2, and when the count reaches a predetermined number or more, the information processing unit 21B determines that the combustion device 30 is malfunctioning and outputs (e.g., notifies) the user of the malfunction. For example, the information processing unit 21B may display the message on the display 24, output a sound from a speaker (not shown), or output the message to another device.

[0071] As described above, the deviation of the comparison data plot from the normal range S1 or S2 indicates the type and / or cause of the malfunction. Therefore, the information processing unit 21B may learn the relationship between the deviation and the type and / or cause of the malfunction using machine learning or the like, identify the type of malfunction based on the learning results and the comparison results, and output the type and / or cause of the malfunction when outputting a malfunction notification. For example, the information processing unit 21B may estimate that a different type of malfunction is occurring in the combustion device 30 based on the tendency of deviation from the normal range of a group out of the plurality of groups, for example, the tendency of deviation, and output the estimated malfunction. For example, if the deviation of the groups out of the normal range tends to deviate from the normal range along the X-axis toward a higher fuel gas flow rate, for example, if a certain percentage or more of the total number of deviated groups deviate toward a higher fuel gas flow rate, the information processing unit 21B estimates that a malfunction has occurred in the combustion device 30, resulting in a decrease in the combustion efficiency, and outputs a notification to that effect. At this time, the information processing unit 21B may output information suggesting a countermeasure for the malfunction, i.e., a message such as, "Please check the heat retention of the combustion chamber R of the combustion device 30." For example, if the deviation of the sets that are out of the normal range tends to deviate from the normal range along the Y axis toward either a higher or lower air ratio, or both, from the normal range, for example, if a certain percentage or more of the total number of deviated sets deviate in the aforementioned direction, the information processing unit 21B may estimate that a malfunction has occurred due to a change in the state of equipment in the combustion device or a misadjustment of the equipment, and output a message to that effect. At this time, the information processing unit 21B may output information suggesting a countermeasure for the malfunction, i.e., a message such as, "Please check or adjust the equipment (such as a damper) of the combustion device."

[0072] The information processing unit 21B does not have to perform the processing for displaying the graph. In other words, the combustion monitoring device 20 may include an information acquiring unit 21A that acquires a plurality of pairs of fuel flow rates among the fuel and air flow rates supplied to a burner of a combustion device and ratio values ​​that indicate the ratio of the air flow rate to a theoretical air amount, and an information processing unit 21B that determines that the combustion device is not normal when a predetermined number or more of the plurality of pairs are outside a predetermined normal range and outputs a message to that effect.

[0073] (Variation 6) Depending on the configuration of the combustion device 30, the air flow meter 66 may not be provided. In such cases, the information acquisition unit 21A acquires the valve opening detected by the opening sensor MS or the operation amount input to the control motor M from the combustion control device 71 and derives a CV value (capacity coefficient) for the acquired value. The information acquisition unit 21A may derive the air flow rate using a known method based on the derived CV value. In this case, two pressure sensors are provided to measure the air pressure on the primary side and the air pressure on the secondary side of the damper 65, respectively. The information acquisition unit 21A acquires the pressures measured by the two pressure sensors via the combustion control device 71 or the like, adds them to the CV value, and derives the air flow rate based on the acquired pressures. The fuel gas flow rate may be represented by a quantity whose increase or decrease is linked to the increase or decrease in the fuel gas flow rate, such as the operation amount or the valve opening that is fed back as described above.

[0074] (Variation 7) The dampers 55 and 65 may be individually controlled by the combustion control device 71. In this case, the opening degrees of each damper may be controlled so that the ratio of the opening degrees of each damper is constant.

[0075] (Variation 8) For example, the information processing unit 21B may execute a process of displaying on the display unit a graph in which a plurality of sets (recent comparison data) acquired by the information acquiring unit 21A are plotted in a coordinate system in which the flow rate of fuel gas is the first axis (which may be the vertical axis) and a ratio value (such as an air ratio) is the second axis (which may be the horizontal axis). Therefore, the information processing unit 21B may display the graph on an external device such as a user's display terminal. Furthermore, as another example, the information processing unit 21B may not generate a graph, but may instead transmit a plurality of comparison data, normal range data, etc. to an external device and cause the external device to generate and display the graph.

[0076] (Variation 9) Instead of fuel gas, other fuels such as liquid fuels, gas-liquid mixtures, etc. may be used.

[0077] (Variation 10) The combustion monitoring device 20 may have any hardware configuration. The combustion monitoring device 20 may be configured as a gateway connecting the combustion control device 71 and the temperature controller 75 with other external devices. At least a portion of the information acquisition unit 21A and the information processing unit 21B may be composed of various logic circuits such as an ASIC (Application Specific Integrated Circuit) and an FPGA (Field-Programmable Gate Array). At least a portion of the units 21A and 21B may be provided in the combustion control device 71 or the temperature controller 75. The combustion monitoring device 20 may be a server computer, a cloud computer, or the like. Devices such as the combustion monitoring device 20 include devices in which the components of the device are integrated into a single housing, as well as systems in which the components of the device are distributed across multiple housings. The combustion monitoring program may be recorded in a non-transitory computer-readable storage medium such as the storage device 23. The state values ​​and the like may be recorded for a fixed period in other storage units such as RAM, which is a volatile storage device.

[0078] (Scope of the present invention) Although the present invention has been described above with reference to the embodiments and modifications, the present invention is not limited to the above embodiments and modifications. For example, the present invention includes various modifications to the above embodiments and modifications that can be understood by a person skilled in the art within the scope of the technical concept of the present invention. The configurations listed in the above embodiments and modifications can be combined as appropriate within a range that does not cause inconsistencies. [Explanation of symbols]

[0079] 10...combustion system, 20...combustion monitoring device, 21...processor, 21A...information acquisition unit, 21B...information processing unit, 23...storage device, 24...display, 25...operation device, 40...combustion equipment, 42...main burner, 43...pilot burner, 44...ignition device, 45...flame detector, 46...temperature sensor, 50...fuel supply system, 55...damper, 56...fuel flow meter, 60...air supply system, 65...damper, 66...air flow meter, 71...combustion control device, 75...temperature controller, M...control motor, MS...opening sensor, P...figure.

Claims

1. an information acquisition unit that acquires a plurality of pairs of a fuel flow rate among the fuel and air flow rates supplied to a burner of the combustion device and a ratio value that indicates a ratio of the air flow rate to a theoretical air amount; an information processing unit that executes processing to display on a display unit a graph in which the plurality of sets acquired by the information acquiring unit are plotted in a coordinate system in which the flow rate of the fuel is represented as a first axis and the ratio value is represented as a second axis; and A combustion monitoring device comprising:

2. the graph indicates a normal range that can be taken by a pair of the fuel flow rate and the ratio value when the combustion device is operating normally; When the combustion device is operating normally, the total number of combustions since the start of operation of the combustion device is equal to or less than a predetermined number. The combustion monitoring device of claim 1.

3. The information acquisition unit acquires the plurality of sets when the total number of combustions is equal to or less than the predetermined number of times and when the total number of combustions exceeds the predetermined number of times, The information processing unit identifying the normal range based on the plurality of sets acquired by the information acquisition unit when the total number of combustions is equal to or less than the predetermined number of times; When the total number of combustions exceeds the predetermined number, the graph obtained by plotting the plurality of sets acquired by the information acquisition unit on the coordinate system is displayed on the display unit.

3. The combustion monitoring device of claim 2.

4. the information processing unit plots the plurality of sets in the coordinate system using a plurality of figures, Each of the plurality of figures is semi-transparent so that when the figures are plotted overlapping each other, the color of the overlapping portion becomes darker. The combustion monitoring device according to any one of claims 1 to 3.

5. the information processing unit determines that the combustion device is not operating normally when a predetermined number or more of the plurality of sets are outside the normal range, and outputs a signal to that effect.

3. The combustion monitoring device of claim 2.

6. The information processing unit estimates that a different type of malfunction is occurring in the combustion device depending on a tendency of deviation of a group that falls outside the normal range from the plurality of groups, and outputs the estimated malfunction.

6. The combustion monitoring device according to claim 5.

7. When the deviation tendency of the set that is outside the normal range is a tendency toward a larger flow rate of the fuel along the first axis from the normal range, the information processing unit estimates that a malfunction in which the combustion efficiency of the combustion device is decreasing is occurring.

7. The combustion monitoring device of claim 6.

8. When the deviation tendency of the set that is outside the normal range is a tendency to deviate from the normal range along the second axis, the information processing unit estimates that a malfunction due to a change in the state of equipment of the combustion apparatus or a misadjustment of equipment has occurred.

7. The combustion monitoring device of claim 6.

9. the information processing unit outputs information suggesting a countermeasure according to the estimated malfunction.

7. The combustion monitoring device of claim 6.

10. On the computer, an information acquisition step of acquiring a plurality of pairs of a fuel flow rate among the fuel and air flow rates supplied to a burner of the combustion device and a ratio value indicating a ratio of the air flow rate to a theoretical air amount; an information processing step of executing a process of displaying on a display unit a graph in which the plurality of sets acquired by the information acquiring step are plotted in a coordinate system in which the flow rate of the fuel is represented as a first axis and the ratio value is represented as a second axis; A combustion monitoring program that executes the above.

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