JP7612465B2 - Delay time monitoring device, delay time monitoring program, and delay time monitoring method - Google Patents

Description

The present invention relates to a delay time monitoring device, a delay time monitoring program, and a delay time monitoring method that monitor the delay time from when a command to start or stop air supply is issued until the air supply state reaches a specified state.

A technology has been developed to check whether an air supply system is normal by monitoring the delay time from when a command to start or stop air supply is issued in a combustion device until the air supply state reaches a specified state. Patent Document 1 discloses a technology that determines that the air supply system is malfunctioning when this delay time falls outside a specified range.

JP 2019-20036 A

The technology described in Patent Document 1 above is also useful, but this technology only determines that the air supply system is malfunctioning when the delay time falls outside a specified range, and does not take into account trends in changes in the delay time. Therefore, there is room for improvement in this technology as well.

The present invention aims to provide a delay time monitoring device, a delay time monitoring program, and a delay time monitoring method that allow users to properly understand malfunctions in the air supply system.

To solve the above problem, the delay time monitoring device according to the first aspect of the present invention includes an acquisition unit configured to acquire the delay time from when a command to start or stop the supply of air is issued in a combustion device until the air supply state reaches a predetermined state, an analysis unit configured to statistically analyze a set of the delay times for each of the multiple commands acquired by the acquisition unit and obtain statistical data of the set as first statistical data, and a comparison unit configured to compare the first statistical data with second statistical data that serves as a reference and is prepared as statistical data of the set of delay times when the command is issued multiple times, and output the comparison result.

The analysis unit may be configured to statistically analyze a set of delay times for the same number of commands issued before a malfunction occurred in the air supply system of the combustion device, acquired by the acquisition unit, using the same method as when the first statistical data was acquired, and to acquire the statistical data of the set as the second statistical data.

The first statistical data may include first distribution data indicating a distribution of the number of delay times belonging to each delay time class, and the second statistical data may include second distribution data indicating a distribution of the number of delay times belonging to each delay time class.

The comparison unit may be configured to compare the first statistical data with the second statistical data by graphing the first distribution data and the second distribution data in association with each other, with a first axis representing delay time classes and a second axis representing the number of delay times, and to output, as the comparison result, each graph of the first distribution data and the second distribution data in association with each other and graphed.

The comparison unit may be configured to estimate the presence or absence of a malfunction in the air supply system of the combustion device based on the difference between the first statistical data and the second statistical data, and to output the result of the estimation as the comparison result.

The first statistical data and the second statistical data may include any one of the following statistical quantities: an average value of the delay time, a mode in a distribution of the number of delay times belonging to each delay time class, and a median in the distribution; and the comparison unit may be configured to estimate that there is a malfunction in the air supply system when the statistical quantity of the first statistical data is greater than the statistical quantity of the second statistical data, and to output a result of the estimation to that effect.

The delay time monitoring program according to the second aspect of the present invention causes a computer to execute an acquisition step of acquiring the delay time from when a command to start or stop air supply is issued in a combustion device until the air supply state reaches a predetermined state, an analysis step of statistically analyzing a set of the delay times for each of the multiple commands acquired in the acquisition step and acquiring statistical data of the set as first statistical data, and a comparison step of comparing the first statistical data with second statistical data that is prepared as a reference for the statistical data of the set of delay times when the command is issued multiple times, and outputting the comparison result.

The delay time monitoring method according to the third aspect of the present invention is a delay time monitoring method for monitoring the delay time from when a command to start or stop air supply is issued in a combustion device until the air supply state becomes a predetermined state, and includes an analysis step of statistically analyzing a set of the delay times for each of a plurality of the commands and obtaining statistical data of the set as first statistical data, and a comparison step of comparing the first statistical data with second statistical data that serves as a reference and is prepared as statistical data of the set of the delay times when the command is issued a plurality of times.

The present invention allows users to properly understand malfunctions in the air supply system.

FIG. 1 is a configuration diagram of a combustion system having a flame monitoring device according to an embodiment of the present invention. FIG. 2 is a timing chart of a combustion sequence executed in the combustion system. FIG. 3 is a diagram showing the hardware configuration of the delay time monitoring device. FIG. 4 is a partial configuration diagram of the delay time monitoring device. FIG. 5 is a flowchart of the delay time storage process executed by the acquisition unit. FIG. 6 is a diagram showing an example of data contents of the delay time group. FIG. 7 is a flowchart of the reference statistical data generation process executed by the analysis unit. FIG. 8 is a diagram showing an example of the data contents of the reference distribution data. FIG. 9 is a graph (frequency line) of the reference distribution data of FIG. FIG. 10 is a graph (frequency line) of the most recent distribution data and the reference distribution data on the same coordinate plane. FIG. 11 is a graph (frequency line) of the most recent distribution data and the reference distribution data on the same coordinate plane. FIG. 12 is a graph (frequency line) of the most recent distribution data and the reference distribution data on the same coordinate plane. FIG. 13 is a flowchart of an estimation result output process executed by a comparison unit according to a modified example. FIG. 14 is a timing chart for explaining the delay time according to the modified example.

The following describes an embodiment of the present invention and its variations with reference to the drawings.

(Embodiment)
As shown in Fig. 1, a delay time monitoring device 20 according to one embodiment of the present invention is used in a combustion system 10. The delay time monitoring device 20 monitors the delay time Td from when a command to start supplying air is issued in a combustion device 30 (described below) of the combustion system 10 until the air supply state reaches a predetermined state. A user can check the presence or absence of a malfunction in the air supply system 60 by checking the monitoring results (comparison results (described below)). "Malfunction" refers to an abnormality that allows the combustion device 30 to operate to the extent that it is not operational, that is, a minor abnormality.

The combustion system 10 includes a delay time monitoring device 20, a combustion device 30 that performs combustion, and a combustion control device 70 that controls the combustion device 30. Below, the combustion device 30 and the combustion control device 70 will be explained first, and then the delay time monitoring device 20 will be explained.

The combustion device 30 includes a combustion device 40, a fuel supply system 50, an air supply system 60, a control motor M, a high opening position sensor HS, and a low opening position sensor LS.

The combustion equipment 40 burns fuel (here, fuel gas) in the combustion chamber R. The combustion equipment 40 is equipped with a combustion furnace 41 that forms the combustion chamber R, a main burner 42 that burns fuel 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. The pilot burner 43 ignited by the ignition device 44 is used to ignite the main burner 42. For this reason, the ignition device 44 can also be said to be a device used when igniting the main burner 42. The ignition device 44 is equipped with a spark generating unit 44A such as a discharge electrode that generates an ignition spark.

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, for example, the flame strength. The type of flame detector 45 is arbitrary, but here, the intensity of the electromagnetic waves (here, ultraviolet rays) emitted from the flame of the main burner 42 or the pilot burner 43 is detected as the flame activity.

Returning to FIG. 1, the fuel supply system 50 supplies fuel from the outside to the combustion appliance 40. The fuel supply system 50 has a fuel flow path 51 through which fuel supplied to the combustion appliance 40 flows. The fuel flow path 51 includes a main flow path 51A through which fuel 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.

The fuel supply system 50 further includes a gas pressure switch 52 provided in the main flow path 51A, main valves 54A and 54B that are safety shutoff valves provided in the first flow path 51B, and pilot valves 54C and 54D that are safety shutoff valves provided in the second flow path 51C. The gas pressure switch 52 is a sensor that turns ON when the pressure of the fuel supplied from the outside is equal to or higher than a predetermined pressure. 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 also includes a damper 55 for adjusting the fuel flow rate provided in the main flow path 51A.

The air supply system 60 supplies air to the combustion appliance 40. The air supply system 60 includes an air flow path 61 through which air supplied to the combustion appliance 40 flows, and a blower 62 that supplies air to the air flow path 61. The air flow path 61 includes a main flow path 61A connected to the blower 62, and a first flow path 61B and a second flow path 61C branched from the main flow path 61A. The first flow path 61B is connected to the main burner 42. The second flow path 61C is connected to the pilot burner 43. The blower 62 may be, for example, a fan, a blower, or a compressor.

The air supply system 60 further includes a wind pressure switch 63, which is a sensor provided in the main flow path 61A and turns ON when the wind pressure of the air blown from the blower 62 is equal to or higher than a predetermined wind pressure. The air supply system 60 further includes a damper 65 for adjusting the air flow rate provided in the main flow path 61A.

The dampers 55 and 65 for adjusting the fuel or air flow rate are driven by a control motor M in a linkage to control the opening of the fuel passage 51 and the air passage 61. Driven by the linkage, the opening of each of the dampers 55 and 65 is controlled so that the air-fuel ratio, which is the ratio of fuel to air supplied to the main burner 42, is maintained at the desired ratio (a ratio within the ideal range for combustion). The amount of fuel and air supplied to the main burner 42 is adjusted by the opening of each of the dampers 55 and 65, which in turn adjusts the flame activity of each burner, thereby controlling the heating temperature for heating the combustion chamber R.

The high opening position sensor HS detects when the opening positions of the dampers 55 and 65 reach a predetermined high opening position. The low opening position sensor LS detects when the opening positions of the dampers 55 and 65 reach a predetermined low opening position. Each sensor HS and LS turns ON when the opening positions of the dampers 55 and 65 reach the high opening position or the low opening position.

The combustion control device 70 is composed of various computers such as a PLC (Programmable Logic Controller) and a personal computer. The combustion control device 70 is also called a burner controller. The combustion control device 70 monitors the states (ON/OFF) of the gas pressure switch 52, the wind pressure switch 63, the high opening position sensor HS, and the low opening position sensor LS. Various signals are input to the combustion control device 70 from the flame detector 45, the temperature sensor 46, and the like. The combustion control device 70 controls the ignition device 44, the main valves 54A and 54B, the pilot valves 54C and 54D, the blower 62, and the dampers 55 and 65, etc., based on the monitoring results and various signals.

The combustion control device 70 executes a combustion sequence that ignites the main burner 42 and the pilot burner 43 to burn fuel, and controls the operation of the combustion device 30. This combustion sequence is determined in advance and includes subsequences such as "start check," "pre-purge," "waiting for ignition," "pilot ignition," "pilot only," "main ignition," "main stable," and "steady combustion."

Figure 2 shows a time chart of the combustion sequence from the start of the combustion device 30 to steady-state combustion. When the combustion control device 70 receives an external start input (point t1 on chart A), it issues an air supply start command (here, an ON signal to start operation) to the blower 62 of the air supply system 60 (point t1 on chart B). In response to this, the blower 62 turns ON and starts blowing air into the air flow path 61. Along with the air supply start command, the combustion control device 70 also sends a drive command to the control motor M in the opening direction (point t1 on chart D). The drive command in the opening direction opens the dampers 55 and 65.

After that, when the wind pressure of the air blown by the blower 62 reaches a predetermined wind pressure, the wind pressure switch 63 turns ON (point t2 on chart C). The period P1 from point t1 to point t2 is the "start check" time period. When the wind pressure switch 63 is ON, it supplies an ON signal to the combustion control device 70. When the combustion control device 70 receives this ON signal, it recognizes that the wind pressure switch 63 is ON (the same applies to the ON of other switches and sensors).

The period P1 is the period from when a command to start supplying air is issued to the air supply system 60 (here, the blower 62) until the sensor (here, the wind pressure switch 63) detects that the air supply state (here, the wind pressure) has reached a predetermined state (here, the state in which the wind pressure has reached a predetermined wind pressure), and is also the delay time Td mentioned above. The combustion control device 70 measures this delay time Td when the combustion sequence is executed.

When the wind pressure switch 63 is turned ON and the high opening position sensor HS detects that the dampers 55 and 65 have reached the high opening position and turns ON (point t3 on Chart E), the combustion control device 70 starts timing the pre-purge time from this point.

After the pre-purge time has elapsed, the combustion control device 70 sends a drive command to the control motor M in the closing direction (point t4 on chart D). This causes the dampers 55 and 65 to move in the closing direction. The period P2 from point t3 to point t4 is the "pre-purge" time period.

When the low opening position sensor LS detects that the opening position of the dampers 55 and 65 has reached the low opening position and turns ON (point t5 in Chart F), after a predetermined waiting time has elapsed, the combustion control device 70 opens the pilot valves 54C and 54D (point t6 in Chart G) and activates the ignition device 44 (point t6 in Chart H). This starts the supply of fuel to the pilot burner 43, and the pilot burner 43 is ignited by an ignition spark generated by the operation of the ignition device 44. The predetermined waiting time is, for example, the time from when the low opening position is detected until the gas pressure switch 52 turns ON after the fuel supply starts. The period P3 from point t4 to point t6 is the "ignition waiting" time period. In this embodiment, the air required for fuel combustion is also supplied to the pilot burner 43 from the air supply system 60. The pilot burner 43 may be configured to be ignited by the surrounding air.

The ignition of the pilot burner 43 is detected by the flame detector 45. The flame detector 45 outputs a detection signal indicating the flame activity of the pilot burner 43 to the combustion control device 70. The combustion control device 70 detects the ignition of the pilot burner 43 when it determines that the flame activity indicated by the detection signal exceeds a predetermined first threshold value. Here, as shown in Chart I, it is assumed that the pilot burner 43 is ignited at point t7 and this ignition is detected.

When the combustion control device 70 detects ignition of the pilot burner 43, it terminates the operation of the ignition device 44, i.e., the generation of the ignition spark (point t8 in chart H). The period P4 from point t6 to point t8 during which the ignition device 44 is operated is the "pilot ignition" time period.

After detecting the ignition of the pilot burner 43 and terminating the operation of the ignition device 44, the combustion control device 70 waits for a predetermined period until point t9. This predetermined period, i.e., the period P5 from point t8 to point t9, is the "pilot only" time period during which the pilot burner 43 burns alone. If, during the above-mentioned predetermined period, the flame activity based on the detection signal from the flame detector 45 falls below a predetermined intensity, the combustion control device 70 determines that the pilot burner 43 has misfired and stops the combustion sequence.

After the above-mentioned predetermined period has elapsed, the combustion control device 70 opens the main valves 54A and 54B (point t9 in Chart J). By opening the main valves 54A and 54B, the supply of fuel to the main burner 42, which is already being supplied with air from the air supply system 60, begins, and the main burner 42 ignites using the flame of the pilot burner 43 as a pilot flame. The flame detector 45 outputs a detection signal indicating the sum of the flame activity of the main burner 42 and the pilot burner 43 to the combustion control device 70. When the combustion control device 70 determines that the sum of the flame activity indicated by the detection signal exceeds a predetermined second threshold, it determines that the main burner 42 has ignited. Here, as shown in Chart K, it is assumed that the main burner 42 is ignited at point t10 and this ignition is detected.

When the combustion control device 70 detects ignition of the main burner 42, it closes the pilot valves 54C and 54D to end the combustion of the pilot burner 54 (see point t11 in charts G and I). The period P6 from point t9 to point t11 is the "main ignition" time period during which the main burner 42 is ignited.

After detecting the ignition of the main burner 42 and closing the pilot valves 54C and 54D, the combustion control device 70 waits for a predetermined period until point t12. This predetermined period, i.e., the period P7 from point t11 to point t12, is the "main stable" time period during which the main burner 42 burns alone. If the flame activity falls below a predetermined intensity during the predetermined period, the combustion control device 70 determines that the main burner 42 has misfired and stops the combustion sequence.

After waiting for the above-mentioned predetermined period, the combustion control device 70 starts feedback control of the control motor M so that the temperature in the combustion chamber R indicated by the detection signal supplied from the temperature sensor 46 becomes the target value, using the temperature as a feedback value (point t12 in chart D). From point t12 onwards, there is a period of "steady combustion" in which the main burner 42 performs steady combustion. The specific method of feedback control in steady combustion is arbitrary, but for example, proportional control (P control), proportional-integral control (PI control), or proportional-integral-derivative control (PID control) is adopted.

The combustion control device 70 outputs the delay time Td measured each time the above series of combustion sequences is executed to the delay time monitoring device 20.

Next, the delay time monitoring device 20 will be described. The delay time monitoring device 20 performs a process of monitoring the delay time Td from the combustion control device 70. The delay time monitoring device 20 is configured to include various computers such as a personal computer. As shown in FIG. 3, the delay time 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 the delay time monitoring program executed by the processor. The storage device 23 also stores the delay time group, most recent statistical data, and reference statistical data described below. The delay time monitoring device 20 further includes a display 24 that displays various screens described below, an operation device 25 operated by a user, and a communication module 26 that allows the processor 21 to communicate with the combustion control device 70.

In this embodiment, the processor 21 operates as the acquisition unit 21A, the analysis unit 21B, and the comparison unit 21C shown in FIG. 4 by executing the delay time monitoring program stored in the storage device 23.

The acquisition unit 21A communicates with the combustion control device 70 via the communication module 26, acquires the delay time Td output from the combustion control device 70 each time the combustion sequence is executed, and stores the delay time Td in the storage device 23. For example, the acquisition unit 21A executes the delay time storage process shown in FIG. 5 each time it acquires the delay time Td.

In the delay time storage process of FIG. 5, the acquisition unit 21A stores the delay time Td acquired from the combustion control device 70 in the Nth (initial value is 0) storage area among the 0th to 49th storage areas provided in the storage device 23 shown in FIG. 6 (step S11). After that, the acquisition unit 21A determines whether N is 49 (step S12), and if N is not 49 (No), adds 1 to N (step S13). If N is 49 (step S12; Yes), the acquisition unit 21A initializes N to 0 (step S14). By such a series of processes, as shown in FIG. 6, when 50 delay times Td of N = 0 to 49 are stored in the storage device 23, the delay times Td obtained thereafter are overwritten starting from N = 0. As a result, the latest 50 delay times Td for each of the air supply start commands issued in each of the latest 50 combustion sequences are always stored in the storage device 23. This data group of 50 delay times Td is the delay time group.

Returning to FIG. 4, the analysis unit 21B statistically analyzes a set of delay times Td (N=0 to 49) that constitute the delay time group stored in the storage device 23 in the early period after the manufacture of the combustion device 30, and obtains the statistical data of the set obtained by this analysis as reference statistical data.

After the combustion device 30 is manufactured, the analysis unit 21B obtains the reference statistical data by starting the reference statistical data generation process shown in FIG. 7 from the first start of operation. In the reference statistical data generation process shown in FIG. 7, the analysis unit 21B first monitors each of the memory areas N=0 to 49 in the memory device 23 and waits until the delay time Td is stored in all of them (step S21). When the delay time Td is stored in each of the memory areas N=0 to 49 (step S21; Yes), the analysis unit 21B reads out a set of 50 delay times Td from each of these memory areas (step S22). The analysis unit 21B then statistically analyzes the set of 50 delay times Td that has been read out (step S23), and stores the statistical data of the set of delay times Td obtained by this analysis in the memory device 23 as reference statistical data (step S24).

In the statistical analysis of step S24, the number of delay times Td belonging to the same preset class is counted as a frequency, as shown in FIG. 8. The reference statistical data includes distribution data showing the distribution of the number of delay times Td belonging to each class of delay times Td, as shown in FIG. 8. The distribution data is also referred to as reference distribution data below. The reference distribution data is a standard for comparison with the most recent distribution data described below. The class may be the value of the delay time Td itself. For example, when the delay time Td is specified in units of 1 ms and is rounded off to the nearest whole number, each of the values of 1 ms, 2 ms, 3 ms, etc. that the delay time Td can take may be treated as a class of the delay time Td. In this case, to be precise, a range of 0.5 to 1.5 can be considered a class, and the above 1, 2, 3, etc. can be considered as class values.

When the reference distribution data shown in FIG. 8 is graphed with the horizontal axis representing the classes of delay time Td and the vertical axis representing the number (frequency) of delay times Td, a graph (frequency line) like that shown in FIG. 9 is obtained. Note that the black circles in the graph in FIG. 9 represent the class values. As shown in FIG. 9, the graph of the reference distribution data has a Gaussian distribution with a narrow width in the horizontal axis direction, i.e., a small standard deviation.

The reference statistical data generation process shown in FIG. 7 may be started before an operational test after the manufacture of the combustion device 30, or may be started after the combustion device 30 goes into full operation after the operational test is completed. The above-mentioned manufacture includes repairing, servicing, modifying, or replacing the combustion device 30, particularly the air supply system 60, to make the combustion device 30 or the air supply system 60 new. The reference statistical data generation process may also be started at any time when the user wishes to register the reference statistical data. In this case, the user issues an instruction to that effect via the operation device 25. The reference statistical data generation process may be executed when there is no malfunction in the air supply system 60.

Returning to FIG. 4, the analysis unit 21B acquires a set of delay times Td constituting the delay time group stored in the storage device 23 at any timing after the reference statistical data is obtained. This set is the set of delay times Td for the most recent 50 executions, which is the same number of times as when the reference statistical data was generated, for each command to start supplying air. The analysis unit 21B statistically analyzes the set of delay times Td, obtains the statistical data of the set obtained by this analysis as the most recent statistical data, and stores it in the storage device 23. The most recent statistical data is used for comparison with the reference statistical data. Note that the number of delay times Td used to generate the most recent reference data and the reference statistical data is not limited to 50 and is arbitrary. Based on the result of this comparison, the user considers whether or not there is a malfunction in the air supply system 60. Therefore, when the user wants to consider whether or not there is a malfunction in the air supply system 60, the user inputs the instruction for the comparison to the operation device 25. In response to this input, the analysis unit 21B performs the statistical analysis and obtains the most recent statistical data.

The analysis unit 21B obtains the most recent statistical data by performing the same analysis method as when obtaining the reference statistical data, for example by performing the same processing as steps S22 to S24 of the reference statistical data generation processing shown in FIG. 7, and stores the most recent statistical data in the storage device 23. Like the reference statistical data, the most recent statistical data includes distribution data (see also FIG. 8) that indicates the distribution of the number of delay times Td that belong to each class of delay times Td. Hereinafter, this distribution data is also referred to as most recent distribution data.

Returning to FIG. 4, when the most recent statistical data is recorded in the storage device 23, the comparison unit 21C reads the most recent statistical data and the reference statistical data from the storage device 23, compares them, and outputs the comparison result.

As shown in Figs. 10 to 12, the comparison unit 21C graphs the most recent distribution data of the most recent statistical data and the reference distribution data of the reference statistical data in relation to each other, with the horizontal axis representing the amplitude class (class value) and the vertical axis representing the frequency. This graphing allows the most recent statistical data to be compared with the reference statistical data. Here, the most recent distribution data and the reference distribution data are graphed in superimposition on a common coordinate plane, so that the two are graphed in relation to each other. The comparison unit 21C outputs images of the graphed most recent distribution data and the reference distribution data (images like those in Figs. 10 to 12) to the display 24 as the comparison result between the most recent statistical data and the reference statistical data, and displays the graphs on the display 24.

When there is no malfunction in the air supply system 60 (before the malfunction occurs), the graph of the most recent distribution data and the graph of the reference distribution data almost overlap, as shown in FIG. 10. On the other hand, when there is a malfunction in the air supply system 60, the two graphs are misaligned, as shown in FIG. 11 and FIG. 12. As the malfunction progresses, the misalignment between the two graphs becomes greater. By checking the comparison results displayed on the display 24, the user can easily visually check whether or not there is a malfunction in the air supply system 60.

In FIG. 11, the graph of the most recent distribution data is shifted in the direction of a longer delay time Td overall compared to the graph of the reference distribution data. If the delay time Td tends to be longer than when there is no abnormality, there is a possibility that the intake of the blower 62 of the air supply system 60 is clogged, or that air is leaking from the piping forming the air flow path 61, etc. has occurred. A user who has confirmed the comparison result as shown in FIG. 11 can confirm that a malfunction has occurred in the air supply system 60, and can infer that the malfunction is the above-mentioned clogging or air leakage, etc. In addition, due to the occurrence of clogging or air leakage, etc., the most recent distribution data graph may have a longer median and average value than the reference distribution data graph, although the mode does not change, as shown in FIG. 12. A user who has confirmed the comparison result as shown in FIG. 12 can also confirm that a malfunction has occurred in the air supply system 60, and can infer that the malfunction is the above-mentioned clogging or air leakage, etc.

As described above, by comparing the graph of the most recent distribution data with the graph of the reference distribution data, if the two graphs are different, the user can know that the air supply system 60 is malfunctioning. In this embodiment, the most recent distribution data and the reference distribution data are obtained by statistical analysis of a set of delay times Td, and the tendency of the change in the delay time Td, that is, the tendency of the malfunction of the air supply system 60, is easily reflected in the comparison result (deviation between the two graphs) between the most recent distribution data and the reference distribution data. Therefore, the user can quickly know the malfunction of the air supply system 60 by checking the comparison result. Furthermore, even if the delay time Td changes significantly due to an unexpected event that is not caused by the malfunction of the air supply system 60, the effect of this is reduced by the statistical analysis, so the user can know with high accuracy whether the air supply system 60 is malfunctioning. As described above, according to this embodiment, the user can properly (here, early or with high accuracy) know the malfunction of the air supply system 60 by looking at the comparison result, that is, the graphs of the most recent distribution data and the reference distribution data.

Malfunctions in the air supply system 60 gradually become more serious. The delay time Td tends to gradually become longer as the severity of the malfunction increases. In the past, when the delay time Td was compared with a threshold value without statistically analyzing it to detect a malfunction, depending on the threshold value, the malfunction may not be detected until the malfunction in the air supply system 60 becomes serious. In this embodiment, statistical analysis is used to make the user aware of the malfunction, so such inconvenience does not occur.

Malfunctions in the air supply system 60, such as clogged air intakes for the blower 62 or air leaks from the piping that forms the air flow path 61, can lead to disturbances in the air-fuel ratio, which is the ratio of fuel to air. Therefore, by checking the graphs of the most recent distribution data and the reference distribution data, the user can quickly identify and address any malfunctions in the air supply system 60 and quickly resolve the disturbances in the air-fuel ratio. This prevents the poor combustion efficiency from continuing.

In the above embodiment, by displaying graphs of the most recent distribution data and the reference distribution data as the comparison results, the user can easily intuitively grasp the difference between the most recent distribution data and the reference distribution data. This makes it possible to efficiently maintain the air supply system 60.

In this embodiment, the reference statistical data to be compared with the most recent statistical data may be, for example, data prepared as a set of statistical data of delay times Td when the combustion sequence is executed multiple times, i.e., when a command to start supplying air is issued multiple times, and serves as a basis for the comparison. For this reason, the reference statistical data may be data obtained in advance from the results of experiments using a combustion device of the same type as the combustion device 30, but in this embodiment, the reference statistical data is prepared based on a set of delay times Td measured in a combustion sequence actually executed by the combustion device 30. This provides reference statistical data that reflects the individual characteristics of the combustion devices 30 that are produced in multiple quantities, allowing the user to more appropriately understand malfunctions in the combustion device 30.

(Modification)
The configuration of the above embodiment can be modified as desired. Modifications are shown below as examples. Each modification can be combined with at least a portion of the others.

(Variation 1)
The configuration of the combustion device 30 is arbitrary. For example, the combustion device 30 may be a type having only the main burner 42 without the pilot burner 43. Also, the combustion device 30 may be in a state in which the pilot burner 43 is constantly ignited. In this case, it is preferable to prepare a flame detector for the main burner 42 and a flame detector for the pilot burner 43.

(Variation 2)
The comparison unit 21C may graph the most recent distribution data of the most recent statistical data and the reference distribution data of the reference statistical data in a manner that correlates them with each other, with the vertical axis representing the class of the delay time Td and the horizontal axis representing the number of delay times Td. The method of graphing the data in a manner that correlates them is not limited to the above-mentioned method of superimposing each graph on a coordinate plane with a common vertical and horizontal axis. For example, each graph may be represented on a different coordinate plane with a common scale of the coordinate axes. In this manner, the method of graphing the data in a manner that correlates them may be, for example, a method of graphing the distribution data in a manner that allows the user to compare them. By graphing the data in a manner that correlates both data, the user can easily understand whether or not there is a malfunction in the air supply system 60.

(Variation 3)
Among the set of delay times Td that are the subject of the statistical analysis, delay times Td that suddenly have abnormal values may be excluded from the analysis.

(Variation 4)
The comparison unit 21C may output an image in which the values of the most recent distribution data and the reference distribution data are written side by side. Even with such numerical values, the user can easily understand the malfunction of the air supply system 60. The most recent statistical data and the reference statistical data may include various statistical quantities such as the average value, the mode value, and the median value, and the comparison unit 21C may output an image in which the respective statistical quantities of the most recent distribution data and the reference distribution data are written side by side.

(Variation 5)
The analysis unit 21B may generate the latest most recent statistical data, for example, every time a new delay time Td is stored in the storage device 23. The comparison unit 21C may estimate the presence or absence of a malfunction of the combustion device 30 based on the difference between the reference statistical data and the most recent statistical data, as shown in Fig. 13 (step S31), and if there is a malfunction (step S32; Yes), may output the estimation result to that effect as a comparison result (step S33). If there is no malfunction (step S32; No), the comparison unit 21C may or may not output the comparison result to that effect.

The analysis unit 21B may obtain, as at least a part of the most recent statistical data and the reference statistical data, any one of the following statistical quantities: the average value of the delay time Td, the mode in the distribution of the number of delay times Td belonging to each class of delay times Td (the above-mentioned distribution data), and the median in the distribution, i.e., the distribution data.

11 and 12, if the most recent statistical data is higher than the reference statistical data in any of the three statistical quantities (including the case where the difference is equal to or greater than a predetermined threshold), it is found that the air supply system 60 has a tendency to malfunction. Therefore, when the average value of the most recent statistical data is higher than the average value of the reference statistical data, the comparison unit 21C may estimate that the air supply system 60 is malfunctioning and output the result of the estimation. When the most recent statistical data is higher than the most recent statistical data, the comparison unit 21C may estimate that the air supply system 60 is malfunctioning and output the result of the estimation. When the median value of the most recent statistical data is higher than the median value of the reference statistical data, the comparison unit 21C may estimate that the air supply system 60 is malfunctioning and output the result of the estimation. When the comparison unit 21C outputs the fact that the air supply system 60 is malfunctioning, for example, it displays information to that effect on the display 24. Examples of such information include messages such as "The air supply system is malfunctioning" or "The air supply system is showing signs of malfunctioning."

As described above, the tendency of changes in the delay time Td, that is, the tendency of malfunction of the air supply system 60, is likely to be reflected in the comparison result between the most recent distribution data and the reference distribution data. Therefore, the above estimation by the comparison unit 21C allows the comparison unit 21C to detect malfunction of the air supply system 60 at an early stage. Furthermore, even if the delay time Td changes significantly due to a sudden event that is not caused by a malfunction of the air supply system 60, this effect is mitigated by statistical analysis, so the comparison unit 21C can estimate with high accuracy whether or not there is a malfunction in the air supply system 60. The user can then properly grasp the malfunction of the air supply system 60 based on the result of the estimation by the comparison unit 21C.

(Variation 6)
In the above-described embodiment, a set of delay times Td from when a command to start supplying air is issued to the air supply system 60 (blower 62) until the supply state of the air becomes a predetermined state (until the wind pressure switch 63 is turned ON) is subject to processing such as statistical analysis. In addition to or instead of the delay time Td, the processing target may be a delay time Td2 that starts from the timing of issuing a command to stop supplying air to the air supply system 60 (blower 62) (here, an OFF signal to the blower 62, etc.). The supply stop command is supplied to the air supply system 60 from the combustion control device 70 at the end of the combustion sequence, etc. The delay time Td2 is a period from when the blower 62 is turned OFF, the amount of air supply decreases, and until the wind pressure switch 63 is turned OFF. The acquisition unit 21A, the analysis unit 21B, and the comparison unit 21C perform the same processing on the delay time Td2 as on the delay time Td. After the blower 62 is stopped, the fan may continue to rotate by inertia, which is different from when the air supply started, and the malfunction may manifest itself in a different way. Even in such a modified example, the same effects as those described above can be obtained as appropriate.

(Variation 7)
In the above embodiment, the air pressure switch 63 is provided upstream of the damper 65 for adjusting the air flow rate, but it may be provided downstream of the damper 65 for adjusting the air flow rate. In this way, malfunction of the damper 65 can also be detected.

(Variation 8)
In the above-described embodiment, the timing when the air supply state (blowing state) reaches a predetermined state is determined by detecting that the wind pressure of the air from the blower 62 has reached a predetermined value using the wind pressure switch 63. As a modification, a flow meter that is a sensor for detecting the flow rate of air may be provided in addition to or instead of the wind pressure switch 63. In this case, the combustion control device 70 may detect the flow rate of air sent from the blower 62 using the flow meter, and may determine the timing when the detected flow rate reaches a predetermined value as the timing when the air supply state reaches the predetermined state, and may end the measurement of the delay time Td or Td2.

(Variation 9)
The specific method of statistical analysis by the analysis unit 21B and the specific method of comparison between the most recent statistical data and the reference statistical data by the comparison unit 21C are arbitrary. As described above, the tendency of change in the delay time Td (or Td2), that is, the tendency of malfunction of the air supply system 60, is likely to be reflected in the comparison result between the most recent distribution data and the reference distribution data. Therefore, the user can grasp the malfunction of the air supply system 60 early by checking the comparison result. In addition, even if the delay time Td changes significantly due to an unexpected event that is not caused by the malfunction of the air supply system 60, the influence of this is reduced by the statistical analysis, so that the user can grasp the presence or absence of malfunction of the air supply system 60 with high accuracy. As described above, according to this embodiment, the user can grasp the malfunction of the air supply system 60 appropriately (here, early or with high accuracy).

(Variation 10)
The flame activity may be indicated by the number of discharges per unit time that occur in the flame detector 45. When the flame activity is high, for example when the ultraviolet ray intensity is high, the number of discharges per unit time increases. In other words, an increase in the number of discharges corresponds to an increase in the voltage value of the flame voltage described above. In such a case, it is preferable to provide the combustion control device 70 with a counting unit that counts the number of discharges and a measuring unit that measures the counting period.

(Modification 11)
The hardware configuration of the delay time monitoring device 20 is arbitrary. The acquisition unit 21A, the analysis unit 21B, and the comparison unit 21C may each be composed of one or more computers or control circuits (such as an ASIC (Application Specific Integrated Circuit) or an FPGA (Field-Programmable Gate Array)). At least a part of the units 21A to 21C may be provided in the combustion control device 70. The delay time monitoring device 20 may be a server computer, a cloud computer, or the like. The output destination of the comparison result may be a display of a user terminal or the like. The output destination of the comparison result may be a printer, a storage medium, a network, another computer, or the like. Each device such as the delay time monitoring device 20 includes a device in which the components of the device are integrated into one housing, as well as a system in which the components of the device are distributed and accommodated in multiple housings.

(Delay time monitoring method)
The delay time monitoring method includes a process executed by the delay time monitoring device 20, which performs statistical analysis and a comparison between the most recent statistical data and the reference statistical data, but at least a part of the method may be performed by an object or person other than the delay time monitoring device 20. By checking the comparison result obtained by comparing the most recent statistical data with the reference statistical data, the user can appropriately grasp the malfunction of the air supply system 60, as described above.

(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 appropriately combined within a range without contradiction.

10...combustion system, 20...delay time monitoring device, 21...processor, 21A...acquisition unit, 21B...analysis unit, 21C...comparison unit, 23...storage device, 25...operation device, 40...combustion equipment, 42...main burner, 43...pilot burner, 44...ignition device, 45...flame detector, 50...fuel supply system, 60...air supply system, 61...air flow path, 62...blower, 63...air pressure switch, 70...combustion control device.

Claims (6)

An acquisition unit configured to acquire a delay time from when a command to start or stop supplying air is issued in the combustion device until the supply state of the air becomes a predetermined state;
an analysis unit configured to statistically analyze a set of the delay times for each of the multiple commands acquired by the acquisition unit, and obtain statistical data of the set as first statistical data;
a comparison unit configured to compare the first statistical data with second statistical data that is prepared as a reference statistical data of a set of delay times when the command is issued a plurality of times, and to output a comparison result ;
The first statistical data includes first distribution data indicating a distribution of the number of delay times belonging to each delay time class,
The second statistical data includes second distribution data indicating a distribution of the number of delay times belonging to each delay time class,
The comparison unit is
a first axis representing the delay time class and a second axis representing the number of delay times, the first distribution data and the second distribution data being correlated with each other and graphed, thereby comparing the first statistical data and the second statistical data;
and outputting, as the comparison result, each graph of the first distribution data and the second distribution data graphed in association with each other.
Delay time monitoring device. The analysis unit is configured to statistically analyze a set of delay times for the same number of commands as the multiple commands issued before a malfunction occurred in the air supply system of the combustion device, which are acquired by the acquisition unit, using the same method as that used to acquire the first statistical data, and to acquire the statistical data of the set as the second statistical data.
2. The delay time monitoring device according to claim 1. The comparison unit is configured to estimate the presence or absence of a malfunction in the air supply system of the combustion device based on a difference between the first statistical data and the second statistical data, and output a result of the estimation as the comparison result.
3. The delay time monitoring device according to claim 1 or 2 . the first statistical data and the second statistical data include any one of statistics of an average value of delay times, a mode in a distribution of the number of delay times belonging to each delay time class, and a median in the distribution,
When the statistical amount of the first statistical data is greater than the statistical amount of the second statistical data, the comparison unit estimates that there is a malfunction in the air supply system and outputs a result of the estimation to that effect.
4. The delay time monitoring device according to claim 3 . A delay time monitoring program that causes a computer to function as the delay time monitoring device according to claim 1 . A delay time monitoring method for monitoring a delay time from when a command to start or stop supplying air is issued in a combustion device until a supply state of the air reaches a predetermined state, comprising:
an analysis step of statistically analyzing a set of the delay times for each of the multiple commands and obtaining statistical data of the set as first statistical data;
a comparison step of comparing the first statistical data with second statistical data that serves as a reference and is prepared as statistical data of a set of the delay times when the command is issued a plurality of times,
The first statistical data includes first distribution data indicating a distribution of the number of delay times belonging to each delay time class,
The second statistical data includes second distribution data indicating a distribution of the number of delay times belonging to each delay time class,
In the comparing step, the first distribution data and the second distribution data are graphed in association with each other, with a first axis representing the class of delay times and a second axis representing the number of delay times, thereby comparing the first statistical data and the second statistical data.
Delay time monitoring method.

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