JP6981798B2 - Combustion system and malfunction determination device - Google Patents

Description

The present invention relates to a combustion system using a combustion control device that controls combustion in the combustion device , and a malfunction determination device .

Conventionally, as this type of combustion system, a combustion system equipped with a combustion device having an air supply system and a fuel supply system to the combustion chamber and a combustion control device for controlling the operation of the combustion device has been used. (For example, see Patent Document 1).

In this combustion system, the air supply system is arranged in an air flow path, a blower that blows air, an air flow path that guides the air blown from the blower to the combustion chamber, and passes through this air flow path. It is equipped with a damper (air flow adjustment damper) that adjusts the air flow rate. The fuel supply system is provided with a damper (fuel flow rate adjustment damper) that links with an air flow rate adjustment damper to adjust its opening position and adjusts the flow rate of fuel supplied to the combustion chamber through the fuel flow path. ing. In some cases, the air flow rate adjusting damper and the fuel flow rate adjusting damper are not linked.

Further, a wind pressure switch for detecting that the pressure of the air blown from the blower has reached a predetermined value is arranged in the air flow path, and this wind pressure switch is turned on and a damper (air flow rate adjusting damper /). The pre-purge time is measured starting from the time when the opening position of the fuel flow rate adjusting damper) reaches a predetermined high opening position. When the pre-purge time is completed, the opening position of the damper (air flow rate adjusting damper / fuel flow rate adjusting damper) is set to a predetermined low opening position.

Japanese Unexamined Patent Publication No. 2011-208921

However, in the conventional combustion system, even if a malfunction (a state within a normal range but deviating from a normal state) occurs in the combustion device, there is no means for recognizing it from the outside. That is, even if an undesired phenomenon such as a decrease in the blower air volume or a slight air leak from the pipe, which is not abnormal but the combustion efficiency is poor, could not be recognized from the outside.

For this reason, the malfunction of the combustion device appears as an abnormality such as a fire break or non-ignition due to the progress of the malfunction, and it can be known only when the operation of the combustion device is stopped due to the abnormality, which hinders the stable operation of the entire combustion system. .. In addition, since it is not known from the outside whether or not there is a malfunction, it was necessary to perform regular maintenance on those that were not actually malfunctioning and did not require maintenance, which led to an increase in cost.

In the above-mentioned Patent Document 1, the abnormality generated in the combustion device is detected, and when the abnormality is detected, the combustion is stopped. In this way, conventionally, it is only to detect that the continuation of combustion has reached an unacceptable abnormality, and although the abnormality can be detected, it takes time to restore the combustion. Therefore, there has been a need to develop a method that can detect a malfunction of the combustion device at an early stage.

The present invention has been made to solve such a problem, and an object thereof is a combustion system capable of identifying the cause of a malfunction of a combustion device and detecting the malfunction at an early stage , and a malfunction. The purpose is to provide a determination device.

In order to achieve such an object, the combustion system according to the present invention includes a combustion device (20) including an air supply system (101) and a fuel supply system (102) to the combustion chamber (5). In the combustion system (100) including the combustion control device (2) that controls the operation of the combustion device, a sensor unit configured to detect that the supply state of air to the combustion chamber has reached a predetermined state. (17) And after at least one of the air supply start command and the supply stop command is issued from the combustion control device to the air supply system, the air supply state to the combustion chamber has reached a predetermined state. The air supply system is within the normal range based on the timer unit (2-2) configured to measure the time until the sensor unit detects, and the time measured by the timer unit, but it is normal. It is characterized by including a malfunction determination unit (2-3) configured to determine whether or not it is in a malfunction state deviated from the state. The malfunction determination device according to the present invention includes the above-mentioned malfunction determination unit (2-3).

In the present invention, for example, when the sensor unit detects that the pressure of the air to the combustion chamber has reached a predetermined value as the air supply state, the air is supplied from the combustion control device to the air supply system. If a supply start command is issued, the time from when this air supply start command is issued until the sensor unit detects that the air pressure to the combustion chamber has reached a predetermined value is measured, and this is measured. Based on the measured time, it is determined whether or not the air supply system is in a malfunctioning state.

For example, in the present invention, the time on the upper limit side of the normal range defined for determining the malfunction of the air supply system is set as the first reference time, and the time defined for determining the abnormality of the air supply system is determined. When the time longer than the reference time of 1 is set as the second reference time and the measured time is between the first reference time and the second reference time, the air supply system is in a malfunctioning state. To judge.

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, after at least one of the air supply start command and the supply stop command is issued from the combustion control device to the air supply system, the air supply state to the combustion chamber is changed. The time until the sensor unit detects that a predetermined state has been reached is measured, and based on this measured time, it is determined whether or not the air supply system is in a malfunctioning state. It is possible to identify the cause of the malfunction of the combustion device and detect it at an early stage.

FIG. 1 is a diagram showing a time T from when the blower is instructed to turn ON until the wind pressure switch is turned ON. FIG. 2 is a diagram showing a time range of normal, normal, abnormal, and malfunction with respect to time T. FIG. 3 is a diagram showing a configuration of an embodiment of a combustion system according to the present invention. FIG. 4 is a diagram illustrating the configuration of a combustion system using only the main burner. FIG. 5 is a time chart of the combustion sequence from the start of the combustion device to the normal combustion. FIG. 6 is a functional block diagram of a main part of a combustion control device provided with a malfunction determination function. FIG. 7 is a flowchart for explaining the malfunction determination function provided in the combustion control device. FIG. 8 is a flowchart for explaining another example of the malfunction determination function provided in this combustion control device. FIG. 9 is a diagram showing an example in which a determination result from a malfunction determination unit is sent to a remote monitoring device (remote monitoring device) connected via the Internet.

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 will be described.

[Outline of Embodiment]
In the present embodiment, among the malfunctions of the combustion device, in order to capture the malfunctions related to the undesired air supply system that causes an inefficient combustion state, if not abnormal, such as a decrease in the blower output and air leakage from the piping. In the combustion control device, the time T from when the blower is instructed to turn ON until the wind pressure switch is turned ON is measured (see FIG. 1). The measurement of this time T is repeated, and the time range that can be taken when there is no malfunction is derived as a normal time range.

For example, the average value of the measured time T is set as the reference time TB (see FIG. 2), and the time zone of ± 10% around the reference time TB is set as the normal time range. Then, when the measured time T is within the normal range (T <TE) but deviates from the normal time range (TL ≦ T ≦ TH), it is determined that there is a malfunction in the air supply system.

Note that TE is a time for determining an abnormality, and is set to be longer than the time TH on the upper limit side of the normal time range, for example, 3 minutes or more. Further, in the present embodiment, the reference time TB may be set as an initial value at the start of operation instead of the average value of the measured time T.

[Embodiment]
FIG. 3 shows the configuration of an embodiment of the combustion system 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 flame detector 9 that detects the intensity of the flame of the burners (pilot burner 7 and the main burner 6), and a temperature sensor 10 that detects the temperature inside 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 dampers (fuel flow rate adjusting dampers) 18 are provided in the first flow path 3b, and the second flow path 3c is provided. The safety shut-off valves 13 and 14 are provided.

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) 19.

In the air flow path 4, the air flow rate adjusting damper 19 is driven by the control motor M1 in a linkage with the fuel flow rate adjusting damper 18. The control motor M1 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 receives a flame detection signal (a signal indicating the flame intensity of the burner) from the flame detector 9 and a temperature detection signal from the temperature sensor 10 as inputs, and the safety shut-off valves 11 to 14 and the ignition device 8 are used. The control signal is output to 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, 9 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 flame detector 9 is referred to as a burner flame. FIG. 3 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 flame detector 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 19 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 shut-off valves 11 to 14 and the fuel flow rate adjusting damper 18 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. 4, 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 18 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. 3), the operation sequence from the start of the combustion device 20 to the normal combustion is defined as a combustion sequence. For example, the operation sequence from the start of the combustion device 20 to the normal combustion is "start check", "pre-purge", "ignition standby", "ignition trial", "pilot trial", "main trial", "normal combustion". As such, the time zone of each combustion sequence is defined.

FIG. 5 shows a time chart of the combustion sequence from the start of the combustion device 20 to the normal combustion. When the combustion control device 2 has a start input (point t1 shown in FIG. 5A), the combustion control device 2 sends a drive command in the opening direction to the control motor M1 to blow air from the blower 16 to the air flow path 4. Start (point t1 shown in FIG. 5D). As a result, the openings of the dampers 18 and 19 are opened, and the pressure in the air flow path 4 increases.

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. 5 (c). ) T2 points).

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. 5 (e)). Point), the timing of the pre-purge time S2 is started from this point in time.

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 M1 (point t4 shown in FIG. 5D). As a result, the openings of the dampers 18 and 19 are closed.

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. 5F), 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 (t7 point shown in FIG. 5 (g)), the ignition device (ignition) 8 was activated (t6 point shown in FIG. 5 (h)). The pilot burner 7 is ignited (point t6 shown in FIG. 5 (i)).

When the combustion control device 2 ignites the pilot burner 7, the safety shut-off valves (main valves) 13 and 14 are opened after waiting for the elapse of the time S3, which is the sum of the pilot ignition time and the pilot only time (FIG. FIG. (T7 point shown in 5 (j)), the main burner 6 is ignited (t7 point shown in FIG. 5 (k)).

When the combustion control device 2 ignites the main burner 6, the combustion control device 2 waits for a 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. 5 (FIG. 5). At t8 point) shown in d), it shifts to 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 malfunction determination function for determining whether or not the combustion device 20 is in a malfunction state. FIG. 6 shows a functional block diagram of a main part of the combustion control device 2 provided with this malfunction determination function.

The combustion control device 2 is realized by hardware consisting of a processor and a storage device and a program that realizes various functions in cooperation with these hardware, and is realized by a combustion control unit 2-1 and a timer unit 2-2. A malfunction determination unit 2-3 and a reference time storage unit 2-4 are provided.

[Reference time storage unit]
In the reference time storage unit 2-4, the time from when the blower 16 is instructed to turn on until the wind pressure switch 17 is turned on, that is, after issuing an air supply start command to the air supply system 101, the combustion chamber 5 Let T be the time until the wind pressure switch 17 detects that the air pressure to reach a predetermined value (the time from the t1 point to the t2 point shown in FIG. 5), and FIG. 2 is preceded by this time T. The time TH on the upper limit side and the time TL on the lower limit side, which define the normal time range derived as described with reference to the above, and the time TE for determining whether it is normal or abnormal are stored. Hereinafter, the time TH is referred to as a first reference time, the time TE is referred to as a second reference time, and the time TL is referred to as a third reference time.

[Failure judgment function]
[Combustion control unit]
The combustion control unit 2-1 turns on the blower 16 (step S101 shown in FIG. 7), and at the same time, starts the measurement of the time T in the timer unit 2-2 (step S102).

[Timer section]
The timer unit 2-2 is at the time when the wind pressure switch 17 is turned on (YES in step S103), that is, when the wind pressure switch 17 detects that the air pressure to the combustion chamber 5 has reached a predetermined value. The measurement of the time T is stopped (step S104). The measured time T is sent to the malfunction determination unit 2-3.

[Failure judgment unit]
The malfunction determination unit 2-3 reads the first reference time TH and the third reference time TL from the reference time storage unit 2-4, and the measurement time T from the timer unit 2-2 is TL ≦ T ≦ TH. It is confirmed whether or not there is, that is, whether or not it is within the normal time range (step S105).

Here, when the measurement time T is not within the normal time range (NO in step S105), the malfunction determination unit 2-3 reads the second reference time TE from the reference time storage unit 2-4, and a timer. It is confirmed whether or not the measurement time T from the part 2-2 is TE ≦ T (step S106).

When the measurement time T is TE ≦ T (YES in step S106), the malfunction determination unit 2-3 determines that the air supply system 101 is abnormal (step S107), and determines the determination result as the monitoring device 30. To display on the screen (monitoring screen) 30-1 of the monitoring device 30 (step S108). In addition, the safety shut-off valves 11 to 14 are closed to shut off the fuel supply to the burner. That is, the combustion device 20 is locked out (step S109).

In this case, for example, an instrumentation diagram of the combustion system 100 is displayed on the monitoring screen 30-1 of the monitoring device 30, and the air supply system 101 in the instrumentation diagram is blinked in red, so that the air supply system is displayed. Notify 101 that an abnormality has occurred.

The malfunction determination unit 2-3 is when the measurement time T is T <TE (NO in step S106), that is, when the measurement time T is between the first reference time TH and the second reference time TE (NO). When TH <T <TE) or the measurement time T is shorter than the third measurement time TL (T <TL), it is determined that the air supply system 101 is in a malfunctioning state (step S110), and the determination thereof is made. The result is sent to the monitoring device 30 and displayed on the monitoring screen 30-1 of the monitoring device 30 (step S111).

In this case, for example, an instrumentation diagram of the combustion system 100 is displayed on the monitoring screen 30-1 of the monitoring device 30, and the air supply system 101 in the instrumentation diagram is blinked in yellow, so that the air supply system is displayed. Let them know that 101 is in a bad state.

In this way, in the present embodiment, the combustion device 20 is in an undesired and unfavorable state, which is normal but has poor combustion efficiency, before the combustion operation of the combustion device 20 becomes abnormal enough to have to be interrupted. It will be possible to detect that there is at an early stage. That is, it becomes possible to detect a sign of an abnormality in the combustion device 20 in advance and notify the manager 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, when the combustion device 20 is in the lockout state, it takes time and effort to restore the combustion device 20, but this can be prevented before the abnormality occurs, so that the burden on the administrator can be reduced. Further, since it is possible to identify that the cause of the malfunction is in the air supply system 101, maintenance can be performed pinpointly.

In the above-described embodiment, it is determined that the device is malfunctioning once, but it may be officially determined that the device is malfunctioning when it is continuously determined that the malfunction is performed a predetermined number of times. FIG. 8 shows a flowchart in this case. In this flowchart, the number of times N determined to be malfunction is counted after step S106 (step S110), and when the number N determined to be malfunction is Nth or more a predetermined number of times (YES in step S111). , It is officially determined that there is a malfunction (step S112), and the determination result is displayed (step S113).

Further, in the above-described embodiment, the time from issuing the air supply start command to the air supply system 101 until the air pressure to the combustion chamber 5 reaches a predetermined value (the wind pressure switch 17 is turned on). (Time until) T is measured, and the malfunction of the air supply system 101 is determined based on the measured time T, but after issuing the air supply stop command to the air supply system 101. The time until the air pressure to the combustion chamber 5 reaches a predetermined value (the time until the wind pressure switch 17 is turned off) is measured, and in the same manner as described above, the air supply system is based on the measured time. The malfunction of 101 may be determined. After the blower 16 is stopped, the fan continues to rotate due to inertia, and the behavior is different from that at the time of air supply, so that the appearance of the malfunction may be different. In this case as well, the measurement shall be repeated to derive the normal time range.

Further, in the above-described embodiment, the wind pressure switch 17 is provided on the upstream side of the air flow rate adjusting damper 19, but it may be provided on the downstream side of the air flow rate adjusting damper 19. By doing so, it is possible to detect not only malfunctions such as a decrease in blower air volume and slight air leakage from piping, but also malfunctions of the air flow rate adjusting damper 19.

Further, in the above-described embodiment, the wind pressure switch 17 detects that the air pressure to the combustion chamber 5 has reached a predetermined value, assuming that the air supply state to the combustion chamber 5 has reached a predetermined state. However, a flow meter may be provided instead of the wind pressure switch 17 so that the flow meter detects that the flow rate of air to the combustion chamber 5 has reached a predetermined value.

Further, in the above-described embodiment, the monitoring device 30 is provided adjacent to the combustion control device 2, but as shown in FIG. 9, a transmission unit 2-5 is provided in the combustion control device 2 and the transmission unit 2-5 is provided. The transmission unit 2-5 sends the determination result from the malfunction determination unit 2-3 to the remote monitoring device (remote monitoring device) 30 via the Internet 40, and displays the determination result on the monitoring screen 30-1 of the monitoring device 30. You may do so.

Further, in the above-described embodiment, the timer unit 2-2, the malfunction determination unit 2-3, and the reference time storage unit 2-4 are provided in the combustion control device 2, but are not necessarily provided in the combustion control device 2. It may not be necessary, and a diagnostic device may be provided separately from the combustion control device 2 and a similar function may be provided in the diagnostic device.

[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, 2-1 ... Combustion control unit, 2-2 ... Timer unit, 2-3 ... Malfunction determination unit, 2-4 ... Reference time storage unit, 3 ... Fuel flow path, 4 ... air flow path, 5 ... combustion chamber, 6 ... main burner, 7 ... pilot burner, 8 ... ignition device, 9 ... flame detector, 11-14 ... safety shutoff valve, 16 ... blower, 17 ... wind pressure switch, 18 ... Damper (fuel flow rate adjustment damper), 19 ... damper (air flow rate adjustment damper), 20 ... combustion device, 30 ... monitoring device, 100 ... combustion system, 101 ... air supply system, 102 ... fuel supply system, HS ... High opening position sensor, LS ... Low opening position sensor, M1 ... Control motor.

Claims (6)

In a combustion system including a combustion device including an air supply system and a fuel supply system to a combustion chamber, and a combustion control device for controlling the operation of the combustion device.
A sensor unit configured to detect that the air supply state to the combustion chamber has reached a predetermined state, and
After the combustion control device issues at least one of an air supply start command and a supply stop command to the air supply system, the air supply state to the combustion chamber reaches the predetermined state. A timer unit configured to measure the time until the sensor unit detects it, and a timer unit.
A malfunction determination unit configured to determine whether or not the air supply system is in a malfunction state that is within the normal range but deviates from the normal state based on the time measured by the timer unit. Equipped with
The malfunction determination unit is defined to determine an abnormality in the air supply system, with the time on the upper limit side of the normal range defined for determining the malfunction of the air supply system as the first reference time. The time longer than the first reference time is set as the second reference time, and the time on the lower limit side of the normal range defined for determining the malfunction of the air supply system is set as the third reference time. When the time measured by the timer unit is between the first reference time and the second reference time or shorter than the third reference time, the air supply system is in a malfunctioning state. A combustion system characterized by determining that. In the combustion system according to claim 1,
The sensor unit is a combustion system characterized in that it detects that the pressure of air to the combustion chamber reaches a predetermined value as the supply state of the air. In the combustion system according to claim 1,
The sensor unit is a combustion system characterized in that it detects that the flow rate of air to the combustion chamber reaches a predetermined value as the supply state of the air. In the combustion system according to any one of claims 1 to 3.
The air supply system is
With a blower that blows air,
An air flow path that guides the air blown from the blower to the combustion chamber,
It is provided with a damper that is arranged in the air flow path and adjusts the flow rate of air passing through the air flow path.
The sensor unit is arranged so as to detect the state of air supply to the combustion chamber on the downstream side of the damper.
The combustion control device is a combustion system characterized in that the operation of the blower and the opening degree of the damper are controlled. In the combustion system according to any one of claims 1 to 4.
The combustion system is characterized in that the malfunction determination unit officially determines that the air supply system is in a malfunction state when it is continuously determined a predetermined number of times that the air supply system is in a malfunction state. A malfunction determination device including the malfunction determination unit in the combustion system according to any one of claims 1 to 5.

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