JP6989343B2 - Frame rod condition judgment device - Google Patents

Description

The present invention relates to a frame rod state determination device that detects the intensity of a flame by a current flowing through an electrode rod inserted into the flame.

Conventionally, as a combustion system, a combustion system including a combustion device including an ignition device and a burner and a combustion control device for controlling the operation of the combustion device according to a predetermined combustion sequence has been used (for example,). See Patent Document 1).

In this combustion system, the operation sequence from the start of the combustion device to the steady combustion is defined as a combustion sequence. For example, "start check", "pre-purge", "waiting for ignition", "pilot ignition", "pilot only", "main ignition", "main stable", as the operation sequence from the start of the combustion device to the steady combustion. Each combustion sequence is defined as "steady combustion".

Further, in this combustion system, the flame intensity of the burner is detected by the frame rod, and the flame detection signal (signal indicating the flame intensity of the burner) from the frame rod is acquired as, for example, the frame voltage VF, and this frame voltage is obtained. The presence or absence of flame and ignition abnormality are judged from the value of VF.

For example, the time from the start of fuel supply to the burner (combustion start) until it is determined that there is a flame (the time until the frame voltage VF reaches a predetermined voltage value) is monitored, and there is a flame even after the predetermined time has passed. If it is not judged, it is judged as non-ignition. If it is determined that the ignition is not ignited, the combustion control device closes the safety shut-off valve and shuts off the fuel supply to the burner. That is, the combustion device is locked out.

Japanese Unexamined Patent Publication No. 2011-208921

However, in the conventional combustion system, if an abnormality occurs in the frame rod, the flame is not detected normally, and it is not determined that there is a flame even though the flame is generated, and the combustion device is locked out. The phenomenon of being in a state sometimes occurred. Once the combustion device is locked out, it may take time to restart and the economic loss may be large.

If it is possible to detect that an abnormality has occurred in the frame rod at an early stage, it is possible to deal with it before the combustion device is locked out, but for that purpose, a skilled engineer is required to use the frame rod. It is necessary to check the condition regularly. In this case, it is uncertain whether or not the frame rod has an abnormality. For this reason, it is necessary to perform regular maintenance even for those that are not actually abnormal and do not require maintenance, which leads to an increase in cost.

It should be noted that the abnormality of the frame rod may be, for example, deterioration of the insulation of the frame rod, rust of the frame rod, poor wiring insulation of the frame rod, poor contact, diving into the spark to the frame rod, or the like.

The present invention has been made to solve such a problem, and an object thereof is a frame rod state determination device capable of early detection of abnormal state such as insulation deterioration of the frame rod. Is to provide.

In order to achieve such an object, the present invention receives the ignition device (8) that ignites the burner (6, 7) and the intensity of the flame of the burner by receiving the ultraviolet rays generated by the generation of the flame. It is a frame rod state determination device (21) that determines the state of the frame rod in the combustion system (100) including the frame rod (9) to be detected, and the intensity of the flame detected by the frame rod is predetermined. It is determined by the flame presence / absence determination unit (21-1) configured to determine that there is a flame when the first reference level (VFmin) is reached, and the flame presence / absence determination unit from the start of combustion to the burner. A timer (21-2) configured to measure the time until the ignition delay time (Td) is set, and an ignition delay time timed by the timer are usually within a predetermined normal range. It is characterized by including a first ignition delay determination unit (21-3) configured to determine that the frame rod is in a malfunction state when it deviates from the range of.

In the present invention, the flame presence / absence determination unit determines that there is a flame when the intensity of the flame detected by the frame rod reaches the first reference level. The timer measures the time from the start of combustion to the burner to the determination that there is a flame as the ignition delay time. The first ignition delay determination unit determines that the frame rod is in a malfunctioning state when the ignition delay time measured by the timer is within the normal range but deviates from the normal range.

For example, if the boundary value on the upper limit side of the normal range is set as the first judgment reference time and the boundary value on the upper limit side of the normal range is set as the second judgment reference time, the ignition timed by the timer is set. When the delay time is between the first determination reference time and the second determination reference time, it is determined that the frame rod is in a malfunctioning state.

In the present invention, for example, when the frame rod is deteriorated in insulation and the degree of the deterioration in insulation is increased, the ignition delay time becomes longer. In this case, it is determined that the frame rod is in a malfunction state when the ignition delay time deviates from the normal range. This makes it possible to detect the deterioration of the insulation of the frame rod at an early stage.

In the present invention, the flame intensity detected by the frame rod may be a frame voltage according to the flame intensity or a frame current. Further, in the present invention, the start of combustion to the burner is the timing that becomes the starting point of the timing start of the ignition delay time, and may be the timing of the start of fuel supply to the burner, or the timing of the start of ignition of the burner. There may be.

In the above description, as an example, the components on the drawing corresponding to the components of the invention are shown by reference numerals in parentheses.

As described above, according to the present invention, if the ignition delay time measured by the timer is within the normal range but deviates from the normal range, it is determined that the frame rod is in a malfunctioning state. This makes it possible to detect abnormalities in the condition such as deterioration of the insulation of the frame rod at an early stage.

FIG. 1 is a time chart for explaining the time (ignition delay time Td) from the start of fuel supply to the burner (fuel valve opening) to the determination that there is a flame. FIG. 2 is a diagram showing a range of normal, normal, abnormal, and malfunction with respect to the ignition delay time Td. FIG. 3 is a diagram showing a range of normal, normal, abnormal, and malfunction with respect to the frame voltage VF. FIG. 4 is a diagram showing a main part of a combustion system including an embodiment of a frame rod state determination device according to the present invention. FIG. 5 is a diagram illustrating the configuration of a combustion system using only the main burner. FIG. 6 is a time chart of the combustion sequence from the start of the combustion device to the steady combustion. FIG. 7 is a functional block diagram of a main part of the frame rod state determination device according to the first embodiment. FIG. 8 is a flowchart for explaining the functions of each part of the frame rod state determination device according to the first embodiment. FIG. 9 is a functional block diagram showing a modified example of the frame rod state determination device according to the first embodiment. FIG. 10 is a diagram showing the logic of the state determination in the first embodiment and the modified examples of the first embodiment in comparison with the prior art. FIG. 11 is a functional block diagram of a main part of the frame rod state determination device according to the second embodiment. FIG. 12 is a functional block diagram of a main part of the frame rod state determination device according to the third embodiment. FIG. 13 is a flowchart corresponding to FIG. 8 in the frame rod state determination device of the third embodiment. FIG. 14 is a diagram showing the contents of abnormalities generated in the frame rod and the contents of changes in data.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. First, before going into the description of the embodiment, the outline of the present embodiment (Embodiments 1 and 2) will be described.

[Outline of Embodiment 1]
If an abnormality occurs in the condition of the frame rod, the ignition delay time will change. For example, if the insulation of the frame rod is deteriorated, the frame rod is rusted, the wiring insulation of the frame rod is poor, or the contact is poor, the ignition delay time becomes long.

In the first embodiment, the time from the start of fuel supply to the burner (fuel valve opening) (t1 point shown in FIG. 1A) to the time when it is determined that there is a flame (up to t2 point shown in FIG. 1B). Time), that is, the time until the flame detection signal (frame voltage VF) from the frame rod becomes VF ≧ VFmin is measured by a timer (FIG. 1 (c)), and the time measured by this timer is the ignition delay time. Let it be Td.

The measurement of the ignition delay time Td is repeated every time the combustion device is started, and the data range that can be taken when there is no malfunction is derived as a normal range.

Then, during the operation of the combustion device, the ignition delay time Td is measured, and when the measured ignition delay time Td is within the normal range but deviates from the normal range, the frame rod is in a malfunctioning state. judge.

For example, the average value of the ignition delay time Td measured repeatedly is set as the reference ignition delay time TdB (see FIG. 2), and the normal range is defined based on this reference ignition delay time TdB. Then, when the measured ignition delay time Td is within the normal range (Td ≦ Tdmax) but deviates from the normal range (Td <TdH), that is, when TdH ≦ Td ≦ Tdmax, the frame rod. Is determined to be in a bad state.

Note that Tdmax is a boundary value for determining an abnormality, and is set longer than the boundary value TdH on the upper limit side of the normal range. Further, the reference ignition delay time TdB may be set as an initial value at the start of operation instead of the average value of the measured ignition delay time Td.

Further, in this example, the flame detection signal from the frame rod is acquired as the frame voltage VF, but it is acquired as the frame current IF, and the frame rod is in a malfunction state in the same manner as the frame voltage VF. It may be determined whether or not.

Further, it may be determined that the ignition delay time Td is in a malfunction state only once from the normal range, or it may be determined that the condition is in a malfunction state after a certain number of deviations or more. May be good. Further, during the operation of the combustion device, when the number of times deviating from the normal range occurs at a certain rate or more, it may be determined that the combustion device is in a malfunctioning state. Further, it may be determined in real time whether or not it is in this malfunctioning state, or it may be confirmed from the operation history.

[Outline of Embodiment 2]
When an abnormality occurs in the state of the frame rod, the frame voltage VF changes. For example, if the insulation of the frame rod is deteriorated, the frame rod is rusted, the wiring insulation of the frame rod is poor, or the contact is poor, the frame voltage VF becomes low.

In the second embodiment, it is determined whether or not the state of the frame rod is malfunctioning not only from the ignition delay time Td but also from the frame voltage VF during steady combustion. That is, if there is a deviation from the normal range for both the ignition delay time Td and the frame voltage VF during steady combustion, it is judged that there is a higher possibility that the frame rod is malfunctioning.

As a measure for this, in the second embodiment, the measurement of the frame voltage VF during steady combustion is repeated every time the combustion device is operated, and the data range that can be taken when there is no malfunction is derived as a normal range.

Then, during the operation of the combustion device, the frame voltage VF during steady combustion is monitored, and when the frame voltage VF during steady combustion is within the normal range but deviates from the normal range, the frame rod is malfunctioning. Determined to be in a state.

For example, the average value of the frame voltage VF during steady combustion measured repeatedly is set as the reference frame voltage VFB (see FIG. 3), and a predetermined range centered on this reference frame voltage VFB is set as the normal range. Then, when the measured frame voltage VF during steady combustion is within the normal range (VFmin ≦ VF ≦ VFmax) but deviates from the normal range (VFL <VF <VFH), the frame rod is in a malfunctioning state. Judged to be in.

Note that VFmin and VFmax are boundary values for determining an abnormality, VFmin is set as a value smaller than the boundary value VFL on the lower limit side of the normal range, and VFmax is set from the boundary value VFH on the upper limit side of the normal range. Is also set as a large value. Further, the reference frame voltage VFB may be set as an initial value at the start of operation, not as an average value of the measured frame voltage VF during steady combustion.

Further, in this example, the flame detection signal from the frame rod is acquired as the frame voltage VF, but it is acquired as the frame current IF, and the frame rod is in a malfunction state in the same manner as the frame voltage VF. It may be determined whether or not.

Further, it may be determined that the frame voltage VF during steady combustion is in a malfunction state due to a short deviation from the normal range, or the average value of the frame voltage VF during steady combustion is taken for a certain period of time. , If this average value deviates from the normal range, it may be determined that the state is in a bad state. Further, when the time outside the normal range is a certain rate or more during steady combustion, it may be determined that the vehicle is in a malfunctioning state. Further, it may be determined in real time whether or not it is in this malfunctioning state, or it may be confirmed from the operation history.

Further, in this example, VFmax is set as the boundary value on the upper limit side of the normal range, and VFH is set as the boundary value on the upper limit side of the normal range, but VFmax and VFH are eliminated, that is, the range of VFmin or more. Is set to the normal range, and when the frame voltage VF during steady combustion exceeds VFL, it is judged to be in the normal state, and when it is between VFmin and VFL, it is judged to be in the malfunction state. You may do it.

[Embodiment]
FIG. 4 shows a main part of a combustion system including an embodiment of a frame rod state determination device according to the present invention. The combustion system 100 includes a combustion device 1, a combustion control device 2, a fuel flow path 3, and an air flow path 4.

The combustion equipment 1 includes a combustion chamber 5, a main burner 6 that heats the inside of the combustion chamber 5, a pilot burner 7 that ignites the main burner 6, an ignition device (IG) 8 that ignites the pilot burner 7. It includes a frame rod 9 for detecting the flame intensity of the burners (pilot burner 7 and main burner 6), and a temperature sensor 10 for detecting the temperature in the combustion chamber 5.

The fuel flow path 3 is a flow path for supplying fuel to the combustion equipment 1, and is a main flow path 3a to which fuel is supplied from the outside, a first flow path 3b branched from the main flow path 3a, and a second flow path. It is composed of a road 3c. The first flow path 3b is connected to the main burner 6, and the second flow path 3c is connected to the pilot burner 7. Further, a gas pressure switch 15 is provided in the main flow path 3a, safety shut-off valves 11 and 12 and a damper (fuel flow rate adjusting damper) 19 are provided in the first flow path 3b, and the second flow path 3c is provided. Is provided with safety shut-off valves 13 and 14.

One end of the air flow path 4 is connected to the blower 16 and the other end is connected to the first flow path 3b. The air discharged from the blower 16 is supplied to the main burner 6 together with the fuel (gas) via the first flow path 3b. Further, the air flow path 4 is provided with a wind pressure switch (air flow switch) 17 and a damper (air flow rate adjusting damper) 18.

In the air flow path 4, the air flow rate adjusting damper 18 is driven by the control motor M in linkage with the fuel flow rate adjusting damper 19. The control motor M includes a high opening position sensor HS that detects that the opening positions of the dampers 18 and 19 have reached a predetermined high opening position, and a low that detects that the opening positions of the dampers 18 and 19 have reached a predetermined low opening position. An opening position sensor LS is provided.

The combustion control device 2 has a gas pressure signal from the gas pressure switch 15, an air pressure signal from the wind pressure switch 17, a flame detection signal from the frame rod 9 (a signal indicating the intensity of the flame of the burner), and a temperature from the temperature sensor 10. The detection signal or the like is input, and the control signal is output to the safety shutoff valves 11 to 14, the ignition device 8, the blower 16, the dampers 18, 19 and the like. As a result, the operation of the combustion device 20 whose component is surrounded by the alternate long and short dash line in the figure is controlled.

Depending on the type of the combustion device 20, there are a type that extinguishes the flame of the pilot burner 7 when the ignition of the main burner 6 is completed, a type that continues the flame of the pilot burner 7 even after the ignition of the main burner 6, and the like. In the former type, first detects the flame intensity of the pilot burner 7, and then detects the flame intensity of the main burner 6. In the latter type, the flame intensities of the pilot burner 7 and the main burner 6 are detected together.

In the present specification, both the pilot burner 7 and the main burner 6 are referred to as burners, and the flame detected by the frame rod 9 is referred to as a burner flame. FIG. 4 shows a type in which the flame of the pilot burner 7 is continued even after the ignition of the main burner 6, and the frame rod 9 detects the flames of the pilot burner 7 and the main burner 6 as the flame of the burner.

Further, in the combustion device 20, the air flow path 4, the blower 16, and the air flow rate adjusting damper 18 constitute an air supply system 101 to the combustion chamber 5, and the fuel flow path 3 (3a, 3b, 3c) and the fuel flow path 3 (3a, 3b, 3c). The safety shutoff valves 11 to 14 and the fuel flow rate adjusting damper 19 constitute a fuel supply system 102 to the combustion chamber 5.

There is also a type in which only the main burner is used without providing a pilot burner, and in that type, as shown in FIG. 5, the flow path (secondary flow) is bypassed between the inlet side and the outlet side of the main flow path 3a. A road) 3c is provided, and a fuel flow rate adjusting damper 19 is installed between the confluence of the main flow path 3a and the sub-flow path 3c on the outlet side and the burner 6. In this case, the burner 6 serves as both the main burner and the pilot burner, and the pilot burner 7 becomes unnecessary.

In this combustion system 100 (FIG. 4), the operation sequence from the start of the combustion device 20 to the steady combustion is defined as a combustion sequence. For example, "start check", "pre-purge", "waiting for ignition", "pilot ignition", "pilot only", "main ignition", "main stable" as the operation sequence from the start of the combustion device 20 to the steady combustion. , "Steady combustion", each combustion sequence is defined.

FIG. 6 shows a time chart of the combustion sequence from the start of the combustion device 20 to the steady combustion. When the combustion control device 2 has a start input (point t1 shown in FIG. 6A), the combustion control device 2 sends a drive command in the opening direction to the control motor M (point t1 shown in FIG. 6D) from the blower 16. Start blowing air to the air flow path 4 (point t1 shown in FIG. 6B). As a result, the dampers 18 and 19 are opened, and the pressure in the air flow path 4 is increased.

Then, when the pressure in the air flow path 4 increases (the pressure of the air in the combustion chamber 5 increases) and the pressure in the air flow path 4 reaches a predetermined value, the wind pressure switch 17 is turned on (FIG. 6 (c). ) T2 points). The period P1 from the t1 point to the t2 point is the time zone of the "start check".

When the combustion control device 2 detects that the wind pressure switch 17 is turned on and the high opening position sensor HS has reached the high opening position of the dampers 18 and 19 (t3 shown in FIG. 6E). Point), the time counting of the pre-purge time S1 is started from this time point.

After the lapse of the pre-purge time S1, the combustion control device 2 sends a drive command in the closing direction to the control motor M (point t4 shown in FIG. 6D). As a result, the openings of the dampers 18 and 19 are closed. The period P2 from the t3 point to the t4 point is the time zone of "pre-purge".

When the combustion control device 2 detects that the opening positions of the dampers 18 and 19 have reached the low opening position (t5 point shown in FIG. 6F), the low opening position sensor LS has a predetermined waiting time S2. After that, the safety shut-off valves (pilot valves) 13 and 14 were opened (t6 point shown in FIG. 6 (g)), and the ignition device (ignition) 8 was activated (t6 point shown in FIG. 6 (h)). The pilot burner 7 is ignited (point t6 shown in FIG. 6 (i)). The period P3 from the t4 point to the t6 point is the time zone of "waiting for ignition".

When the combustion control device 2 ignites the pilot burner 7, it waits for the elapse of the time S3, which is the sum of the pilot ignition time and the pilot only time, and opens the safety shut-off valves (main valves) 11 and 12 (Fig.). (T8 point shown in 6 (j)), the main burner 6 is ignited (t8 point shown in FIG. 6 (k)). In this case, the period during which the ignition device 8 is operated, that is, the period P4 from the t6 point to the t7 point shown in FIG. 6 (h) is the time zone of "pilot ignition", and the period P5 from the t7 point to the t8 point. Is the "pilot only" time zone.

When the combustion control device 2 ignites the main burner 6, the combustion control device 2 waits for the elapse of the time S4, which is the sum of the main ignition time and the main stabilization time, and starts proportional control of the opening degrees of the dampers 18 and 19 (FIG. 6 (d), t10 point), shift to steady combustion. Of the period from t8 point to t10 point, the period P6 from t8 point to t9 point is the time zone of "main ignition", and the period P7 from t9 point to t10 point is the time zone of "main stable". Yes, the period P8 after the t10 point is the time zone of "steady combustion".

In the present embodiment, the combustion control device 2 that performs an operation according to such a combustion sequence is provided with a frame rod state determination device 21 that determines the state of the frame rod 9. That is, as one of the functions of the combustion control device 2, a function of determining the state of the frame rod is provided. The state determination device 21 of the frame rod may be provided outside the combustion control device 2 instead of inside the combustion control device 2.

[Embodiment 1]
FIG. 7 shows a functional block diagram of a main part of the frame rod state determination device (frame rod state determination device) of the first embodiment. The frame rod state determination device 21 is realized by hardware including a processor and a storage device, and a program that realizes various functions in cooperation with these hardware.

The frame rod state determination device 21 has a flame presence / absence determination unit 21-1, a timer 21-2, a first ignition delay determination unit 21-3, and a second ignition as functional units peculiar to the present embodiment. It includes a delay determination unit 21-4, a frame voltage determination reference level storage unit 21-5, a determination reference time storage unit 21-6, and a determination result output unit 21-7.

In the frame rod state determination device 21, the frame voltage determination reference level storage unit 21-5 stores the reference level VFmin as a threshold value for determining the presence or absence of a flame. The determination reference time storage unit 21-6 has a boundary between the first determination reference time Tdmax, which is the boundary value on the upper limit side of the normal range, and the upper limit side boundary of the normal range, as the determination reference time for the ignition delay time Td. The second determination reference time TdH as a value is stored. The second determination reference time TdH is derived as described above with reference to FIG.

Hereinafter, the functions of each part of the frame rod state determination device 21 will be described with reference to the flowchart shown in FIG.

In the frame rod state determination device 21, the timer 21-2 starts the timing operation starting from the start of fuel supply to the burner (fuel valve opening) (YES in step S101) (step S102). In this example, the timing at which the pilot valves 13 and 14 are opened (point t6 shown in FIG. 6 (g)) is defined as the fuel supply start timing to the burner.

The flame presence / absence determination unit 21-1 monitors the flame detection signal (frame voltage VF) from the frame rod 9 (step S103), and the frame voltage VF is stored in the frame voltage determination reference level storage unit 21-5. When the level Vmin is reached (YES in step S104), it is determined that there is a flame, and the timing operation of the timer 21-2 is stopped (step S105). The timer 21-2 sets the timed time T at this time as the ignition delay time Td and sends it to the first ignition delay determination unit 21-3 (step S106).

The first ignition delay determination unit 21-3 compares the ignition delay time Td from the timer 21-2 with the second determination reference time TdH stored in the determination reference time storage unit 21-6 (step S107). ), When Td <TdH (YES in step S107), it is determined that the frame rod 9 is in a normal state (step S109).

When Td <TdH, that is, when Td ≧ TdH (NO in step S107), the first ignition delay determination unit 21-3 determines that the frame rod 9 is in a malfunctioning state (step S108). ).

The timer 21-2 continues the timekeeping operation while the frame voltage VF is VF <VFmin (NO in step S104). The second ignition delay determination unit 21-4 monitors the time T of the timer 21-2 (step S110), and the time T of the timer 21-2 is stored in the determination reference time storage unit 21-6. When the first determination reference time Tdmax is exceeded (YES in step S111), it is determined that the frame rod 9 is in an abnormal state (step S112). Then, the timing operation of the timer 21-2 is stopped (step S113).

In the present embodiment, the ignition delay time Td is sent from the timer 21-2 to the first ignition delay determination unit 21-3 and does not exceed Tdmax. Therefore, it can be said that the ignition delay time Td when the first ignition delay determination unit 21-3 determines that there is a malfunction is TdH ≦ Td ≦ Tdmax.

The determination results obtained by the first ignition delay determination unit 21-3 and the second ignition delay determination unit 21-4 are sent to the determination result output unit 21-7. The determination result output unit 21-7 sends the determination results from the first ignition delay determination unit 21-3 and the second ignition delay determination unit 21-4 to the monitoring device 30, and the screen (monitoring screen) of the monitoring device 30. Display on 30-1.

The monitoring device 30 may be inside the combustion control device 2 or may be provided outside the combustion control device 2. Further, the monitoring device 30 may be provided at a remote location via the Internet.

[Modified Example of Embodiment 1]
In this frame rod state determination device 21, VFmin is set to the first reference level (boundary value on the lower limit side of the normal range of the frame voltage VF), and the second reference level VFmax is set to the upper limit side of the normal range of the frame voltage VF. The frame rod 9 may be determined to be in an abnormal state when the frame voltage VF exceeds VFmax.

FIG. 9 shows a configuration example (a modification of the first embodiment) of the frame rod state determination device 21 in which the frame rod 9 is determined to be in an abnormal state when the frame voltage VF exceeds VFmax. show. Hereinafter, the frame rod state determination device 21 shown in FIG. 7 will be referred to as 21A, and the frame rod state determination device 21 shown in FIG. 9 will be referred to as 21B, and both will be described separately.

In the frame rod state determination device 21B shown in FIG. 9, the frame voltage determination reference level storage unit 21-5 is configured to store the first reference level VFmin and the second reference level VFmax. Then, a flame level determination unit 21-8 is provided, and when the frame voltage VF exceeds the second reference level VFmax, it is determined that the frame rod 9 is in an abnormal state, and the determination result is determined as the determination result output unit 21. I try to send it to -7.

[Comparison of state judgment logic]
FIG. 10 shows the logic of state determination in the frame rod state determination devices 21A and 21B in comparison with the prior art. 10 (a) is a state determination logic of the prior art, FIG. 10 (b) is a state determination logic in the frame rod state determination device 21A, and FIG. 10 (c) is a state determination logic in the frame rod state determination device 21B. Is shown.

In the prior art (FIG. 10A), the reference level VFmin, which is the boundary value on the lower limit side of the normal range with respect to the frame voltage VF, and the determination reference time Tdmax, which is the boundary value on the upper limit side of the normal range with respect to the ignition delay time Td, are set. When the frame voltage VF reaches VFmin (VF ≧ VFmin) before the timekeeping time T exceeds the judgment reference time Tdmax (T ≦ Tdmax), it is judged as “normal” and the timekeeping time T is the judgment reference. When the time Tdmax was exceeded (T> Tdmax), it was determined to be "abnormal". When the frame voltage VF is VF <VFmin, the determination of "normal" / "abnormal" is not performed until the time counting time T exceeds the determination reference time Tdmax.

On the other hand, in the frame rod state determination device 21A, as shown in FIG. 10B, the determination reference time Tdmax (the boundary value on the upper limit side of the normal range with respect to the ignition delay time Td) is set as the first determination reference time. A second determination reference time TdH (boundary value on the upper limit side of the normal range with respect to the ignition delay time Td) is provided before the first determination reference time Tdmax, and the time counting time T is between TdH and Tdmax. When the frame voltage VF reaches VFmin (VF ≧ VFmin) in a certain case (TdH ≦ T ≦ Tdmax), it is determined as “malfunction”, and before the time counting time T reaches the second judgment reference time TdH (T < When the frame voltage VF reaches VFmin (VF ≧ VFmin) in TdH), it is determined as “normal”.

That is, in the frame rod state determination device 21A, the region determined to be "normal" in the determination logic of the prior art (FIG. 10A) is "normal" and "malfunction" in the direction of the horizontal axis indicating the time counting time T. It is supposed to be divided into the judgment areas of.

In the frame rod state determination device 21B, as shown in FIG. 10 (c), the reference level VFmin (the boundary value on the lower limit side of the normal range with respect to the frame voltage VF) is set as the first reference level, and this first reference level is set. A second reference level VFmax (boundary value on the upper limit side of the normal range with respect to the frame voltage VF) is provided at a position higher than VFmin, and when the frame voltage VF exceeds VFmax (VF> VFmax), it is regarded as "abnormal". judge.

That is, in the frame rod state determination device 21B, in the determination logic of the frame rod state determination device 21A (FIG. 10B), the region determined as "normal" in the direction of the vertical axis indicating the frame voltage VF is "normal". It is divided into "normal" and "abnormal" judgment areas, and the area judged as "malfunction" is divided into "malfunction" and "abnormal" judgment areas.

[Embodiment 2]
FIG. 11 shows a functional block diagram of a main part of the frame rod state determination device according to the second embodiment. In this frame rod state determination device 21 (21C), the frame rod state determination device 21A (FIG. 7) of the first embodiment is used as a basis, and the combustion flame level determination unit 21-is further added to the configuration of the frame rod state determination device 21A. 9 is provided.

Further, in this frame rod state determination device 21C, the frame voltage determination reference level storage unit 21-5 has a first reference level VFmin (a boundary value on the lower limit side of the normal range with respect to the frame voltage VF) and a second reference. Level VFmax (boundary value on the upper limit side of the normal range for the frame voltage VF), third reference level VFL (boundary value on the lower limit side of the normal range for the frame voltage VF), and fourth reference level VFH (frame). The boundary value on the upper limit side of the normal range with respect to the voltage VF) is stored. The third reference level VF and the fourth reference level VFH are derived as described above with reference to FIG.

In this frame rod state determination device 21C, the flame level determination unit 21-9 during combustion monitors the frame voltage VF during steady combustion, and the frame voltage VF during steady combustion is the first reference level VFmin and the third reference. The frame rod 9 is in a malfunction state when it is between the level VFL (VFmin ≦ VF ≦ VFL) or between the second reference level VFmax and the fourth reference level VFH (VFH ≦ VF ≦ VFmax). When the frame voltage VF during steady combustion is below the first reference level VFmin (VF <VFmin) or exceeds the second reference level VFmax (VF> VFmax), the frame rod 9 is determined to be. When it is determined that the condition is abnormal and the frame voltage VF during steady combustion is between the third reference level VL and the fourth reference level VH (VL <VF <VH), the frame rod 9 is normal. Determined to be in a state.

[Embodiment 3]
FIG. 12 shows a functional block diagram of a main part of the frame rod state determination device according to the third embodiment. The frame rod state determination device 21 (21D) is based on the frame rod state determination device 21A (FIG. 7) of the first embodiment, and further has an ignition delay time storage unit 21-10 in the configuration of the frame rod state determination device 21A. And a third ignition delay determination unit 21-11 are provided.

Each time the ignition delay time Td is timed by the timer 21-2, the ignition delay time storage unit 21-10 stores the ignition delay time Td in chronological order. Each time the ignition delay time Td is timed by the timer 21-2, the third ignition delay determination unit 21-11 sets the ignition delay time Tdn measured this time and the ignition delay time Tdn _-1 measured last time in the past. When it is determined that the long-short relationship has been reversed, it is determined that the frame rod 9 is in an abnormal state, and the determination result is determined by the determination result output unit 21-. Send to 7.

For example, when an abnormality such as a spark jumping into the frame rod 9 occurs, the ignition delay time Td becomes longer or shorter. In the frame rod state determination device 21D of the third embodiment, the ignition delay time Tdn measured this time and the ignition delay time Tdn _-1 measured last time are compared retroactively and the long-short relationship is determined. It also detects anomalies such as sparks jumping into the frame rod 9. FIG. 14 shows the contents of the abnormality generated in the frame rod 9 and the contents of the data change.

In this embodiment, the ignition delay time Tdn measured this time and the ignition delay time Tdn _-1 measured last time are compared retroactively. For example, they are stored in the ignition delay time storage unit 21-10. Regarding the ignition delay time Td for a predetermined period up to the present, the ignition delay time Td before and after adjacent to each other shall be compared _{as the ignition delay time Tdn measured this time and the ignition delay time Tdn -1 measured last time.} .. Then, a threshold value is set for the number of times the reversal has occurred, and it is determined whether or not the reversal has occurred in the long-short relationship.

FIG. 13 shows a flowchart corresponding to FIG. 8 in the frame rod state determination device 21D. In the figure, the processes of steps S201 to S206 correspond to the processes of steps S101 to S106 in FIG. 7, the processes of steps S210 to S216 correspond to the processes of steps S107 to S113 in FIG. 7, and the description thereof will be omitted.

In the frame rod state determination device 21D, in step S207, the ignition delay time Td is set as Tdn and the ignition delay time storage unit 21-10 is stored. Then, in step S208, the ignition delay time Tdn measured this time and the ignition delay time Tdn _-1 measured last time are compared retroactively, and the long-short relationship is determined. Here, when it is determined that the long-short relationship has been reversed (YES in step S209), it is determined that the frame rod 9 is in an abnormal state (step S215).

In this way, in the present embodiment (Embodiments 1, 2, 3), it is possible to know at an early stage that the frame rod 9 is in a normal but unwell state before the state of the frame rod 9 becomes abnormal. Will be able to. That is, it becomes possible to detect an abnormality in the state such as insulation deterioration of the frame rod 9 in advance and notify the administrator of the necessity of maintenance at an early stage before the abnormal state occurs. This eliminates the need for frequent maintenance and avoids cost increases.

Further, if the combustion device 20 is in the lockout state, it takes time and effort to restore it, but this can be prevented before the lockout state is reached, that is, the abnormality in the state of the frame rod 9 can be efficiently advanced in advance. By detecting and removing it, the burden on the administrator can be reduced.

Further, in the second embodiment, the determination result of "normal" / "abnormal" / "malfunction" of the frame rod 9 can be obtained for both the ignition delay time Td and the frame voltage VF during steady combustion. Here, when the determination result of "malfunction" is obtained not only for the ignition delay time Td but also for the frame voltage VF, it can be determined that there is a higher possibility that the frame rod 9 is malfunctioning. This enhances the reliability of the malfunction determination.

Further, as described in "Outline of the embodiment", in the above-described first to third embodiments, the flame detection signal from the frame rod 9 is acquired as the frame current IF, and the same as the frame voltage VF. The determination of "normal" / "abnormal" / "malfunction" of the frame rod 9 may be performed.

Further, in the first to third embodiments, the ignition delay time Td is measured with the timing at which the pilot valves 13 and 14 are opened as the fuel supply start timing to the burner, but the main valves 11 and 12 are opened. The ignition delay time Td may be measured by setting the timing as the timing of starting the supply of fuel to the burner. Further, the ignition delay time Td from the start of combustion may be measured by setting the start of ignition to the ignition device 8 as the timing of the start of combustion to the burner instead of the start of supply of fuel to the burner.

〔others〕
If the ignition delay time and the change in the frame voltage are confirmed when the ignition detection is not performed normally and the combustion device is locked out, it is possible to investigate the cause of the influence of the abnormal condition of the frame rod. Is also available.

It is also possible to grasp the problem of the combustion state by observing the ignition delay time and the change with time of the frame voltage. For example, when the ignition delay time increases and the frame voltage during combustion gradually decreases, it can be determined that abnormalities such as rust and insulation deterioration of the frame rod gradually progress. In that case, it can be determined that there is a high possibility that there is a problem in the installation environment of the frame rod. By utilizing this, it is possible to detect an abnormality in the frame rod and prevent reoccurrence by optimizing the installation environment.

[Extension of Embodiment]
Although the present invention has been described above with reference to the embodiments, the present invention is not limited to the above embodiments. Various changes that can be understood by those skilled in the art can be made to the structure and details of the present invention within the scope of the technical idea of the present invention.

1 ... Combustion equipment, 2 ... Combustion control device, 6 ... Main burner, 7 ... Pilot burner, 8 ... Ignition device (ignition), 11, 12 ... Safety shutoff valve (main valve), 13, 14 ... Safety shutoff valve (pilot) Valve), 21 (21A, 21B, 21C, 21D) ... Frame rod state determination device, 21-1 ... Flame presence / absence determination unit, 21-2 ... Timer, 21-3 ... First ignition delay determination unit, 21-4 ... Second ignition delay determination unit, 21-5 ... Frame voltage determination reference level storage unit, 21-6 ... Judgment reference time storage unit, 21-7 ... Judgment result output unit, 21-8 ... Flame level determination unit, 21 -9 ... Combustion flame level determination unit, 21-10 ... Ignition delay time storage unit, 21-11 ... Third ignition delay determination unit, 100 ... Combustion system.

Claims (7)

Determines the state of the frame rod in a combustion system comprising an igniter that ignites the burner and a frame rod that detects the intensity of the burner's flame by the current flowing through an electrode rod inserted into the flame. It is a state judgment device of the frame rod to be used.
A flame presence / absence determination unit configured to determine that there is a flame when the intensity of the flame detected by the frame rod reaches a predetermined first reference level.
A timer configured to measure the time from the start of combustion to the burner to the determination by the flame presence / absence determination unit as the ignition delay time.
If the ignition delay time timed by the timer is within a predetermined normal range but deviates from the normal range, it is configured to determine that the frame rod is in a malfunctioning state. a first ignition delay determination unit,
When the first ignition delay determination unit determines that the frame rod is in a malfunctioning state, a determination result output unit that outputs to that effect, and a determination result output unit.
A frame rod state determination device comprising. In the frame rod state determination device according to claim 1,
Judgment reference time storage for storing the first determination reference time defined as the boundary value on the upper limit side of the normal range and the second determination reference time defined as the boundary value on the upper limit side of the normal range. With a department,
In the first ignition delay determination unit, the frame rod is in a malfunction state when the ignition delay time measured by the timer is between the first determination reference time and the second determination reference time. A frame rod state determination device characterized by determining that. In the frame rod state determination device according to claim 2,
The first ignition delay determination unit is
When the ignition delay time measured by the timer is between the first determination reference time and the second determination reference time, it is determined that the frame rod is in a malfunctioning state.
A frame rod state determination device for determining that the frame rod is in a normal state when the ignition delay time measured by the timer is less than the second determination reference time. In the frame rod state determination device according to claim 2 or 3.
A second ignition delay determination unit configured to monitor the time of the timer and determine that the frame rod is in an abnormal state when the time exceeds the first determination reference time. A frame rod state determination device characterized by being provided. In the frame rod state determination device according to any one of claims 1 to 4.
The first reference level is set as the boundary value on the lower limit side of the normal range of the flame intensity, and the second reference level higher than the first reference level is the upper limit of the normal range of the flame intensity. Judgment standard level storage unit that stores as the boundary value on the side,
When the intensity of the flame detected by the frame rod exceeds the second reference level, it is determined that the frame rod is in an abnormal state even if the ignition delay time is within the normal range. A frame rod state determination device characterized by being provided with a flame level determination unit configured in. In the frame rod state determination device according to any one of claims 1 to 4.
The first reference level is set as the boundary value on the lower limit side of the normal range of the flame intensity, and the second reference level higher than the first reference level is the upper limit of the normal range of the flame intensity. As the side boundary value, the third reference level higher than the first reference level and lower than the second reference level is set as the lower limit side boundary value of the normal range of the flame intensity. A determination reference level storage unit that stores a fourth reference level lower than the reference level of the above and higher than the third reference level as a boundary value on the upper limit side of the normal range.
When the intensity of the flame during steady combustion of the burner detected by the frame rod is monitored and the intensity of the flame during steady combustion is between the first reference level and the third reference level. Alternatively, when it is between the second reference level and the fourth reference level, it is determined that the frame rod is in a malfunctioning state, and the intensity of the flame during the steady combustion is the first reference level. When it falls below or exceeds the second reference level, it is determined that the frame rod is in an abnormal state, and the intensity of the flame during the steady combustion is the third reference level and the fourth reference level. A frame rod state determination device including a combustion flame level determination unit configured to determine that the frame rod is in a normal state when it is between the reference level. In the frame rod state determination device according to any one of claims 1 to 6, the frame rod state determination device.
Every time the ignition delay time is timed by the timer, the ignition delay time timed this time and the ignition delay time measured last time are compared retroactively to determine the long-short relationship, and the long-short relationship is reversed. The frame rod includes a third ignition delay determination unit configured to determine that the spark emitted by the ignition device is in an abnormal state in which the spark is jumped.
The determination result output unit outputs to that effect when the third ignition delay determination unit determines that the frame rod is in an abnormal state in which the spark jumps.
A frame rod state determination device comprising.

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