JP5121561B2 - Combustion state detection device - Google Patents

Description

  The present invention relates to a combustion state detection device that detects a combustion state of a combustion device.

  Conventionally, in this type, for example, a flame detecting means for detecting the presence or absence of a flame is provided, and a flame sensor such as CdS or a semiconductor optical sensor is used as the flame detecting means. The amount of flame is detected and a high signal or low signal is generated. The presence or absence of a flame is judged based on this signal, and if the flame disappears during combustion, the fuel supply is stopped.

  In other words, when there is a flame during combustion, this flame sensor determines that the flame sensor output is higher than the reference level due to the light of the flame, and that there is a flame with a high signal higher than this reference level. When is disappeared, the output of the flame sensor becomes lower than the reference level because there is no light of the flame, and it is determined that there is no flame based on a low signal lower than the reference level.

  And about the detection of the disconnection failure and the short circuit failure of the flame sensor, if the output of the flame sensor is lower than the reference level during combustion, it is determined that the flame sensor is disconnected, and the output of the flame sensor is higher than the reference level during combustion stop. And it was judged as a short circuit failure of the flame sensor.

  Also, when the combustion burner part is removed and reattached for maintenance, etc., if the combustion operation is performed with the attachment incomplete, the high temperature exhaust gas leaks from the combustion burner attachment part, and the burner part and the receiving side of the burner part are abnormal. Since it becomes high temperature, a thermal fuse, a thermostat, etc. were attached to the burner part and the receiving side of the burner part, and it was operated when there was a leak of exhaust gas, and the combustion operation was stopped.

By the way, with this conventional one, the input to the flame sensor is temporarily interrupted during combustion, and at this time, when the output of the flame sensor is a high signal higher than the reference level, it is determined that the flame sensor is abnormal and combustion is stopped. When the input to the flame sensor is temporarily interrupted, the output of the flame sensor may be erroneously detected as a high signal higher than the reference level due to noise and stop combustion, and the reference level is set to prevent this. Switching to the second reference value, which is a level at which it is temporarily determined that there is abnormal combustion, and when there is an output from the flame sensor indicating that there is a flame, it is determined that the flame sensor is abnormal and combustion is stopped. (For example, see Patent Document 1)
Japanese Patent Application Laid-Open No. 11-241821

  By the way, in this conventional combustion state detection device, the reference level is switched to the second reference value that is a level for determining abnormal combustion. At this time, when there is an output of the flame sensor indicating that there is a flame, Although it was judged and the combustion was stopped, the output of the flame sensor accidentally caused a flame due to a temporary change of the flame, and it was sometimes judged that the flame sensor was abnormal although it was not abnormal.

In addition to the flame detection, an abnormally high temperature detecting means for detecting the abnormally high temperature of the burner portion due to the leakage of exhaust gas from the combustion burner mounting portion and the receiving side of the burner portion and stopping the combustion operation is required.

  In order to solve the above-mentioned problems by focusing attention on this point, the present invention is particularly configured as claimed in claim 1, wherein the flame detection unit includes a flame detection unit that changes the output according to the combustion state of the burner unit, and the flame detection An abnormality determination unit including a flame determination unit that compares the output value from the unit with a reference value, determines the presence or absence of a flame based on the magnitude determination, and outputs a signal with a flame or a signal without a flame, and the abnormality A control unit that determines whether the combustion state and the flame detection means are normal or abnormal depending on whether the flame presence signal or the flame absence signal from the determination unit coincides with the combustion operation or the combustion stop state at that time. The control unit determines that the reference value of the flame determination unit during the combustion state is higher than the first level that the flame detection means does not reach when the flame detection means is normal but does not reach when the flame detection means is abnormal Switch to the second level, and the flame determination unit The flame detection means may have malfunctioned during the combustion state when comparing the reference value of the flame and the output value from the flame detector and determining the presence or absence of flame based on the magnitude judgment and outputting a flame presence signal Since the combustion operation is temporarily stopped and extinguished, the reference value of the flame determination unit is switched from the second level to the first level in the extinguishing state, and in the extinguishing state, the flame determination unit and the reference value of the first level Comparing the output value from the flame detector, and judging the presence or absence of flame based on the magnitude judgment and outputting the flame presence signal, it is judged that an abnormality has occurred in the flame detection means during the combustion state It is.

  Further, in the combustion state detection device according to claim 2, in particular, in the combustion state detection device according to claim 1, the flame detection means includes a sensor that outputs light by receiving flame light, and the abnormality determination unit includes Is a third level that is lower than the reference value of the first level of the flame detection unit and higher than the level output by the normal flame detection means after the combustion is stopped, and the third level reference level and after the combustion stop The output of the flame detection unit is compared, and when the output of the flame detection unit is higher than a reference level, an abnormal temperature determination unit that outputs an abnormal signal is provided, and the control unit outputs an abnormal signal from the abnormal temperature determination unit. When the time continues, it is determined that an abnormally high temperature has occurred around the burner part due to exhaust gas leakage or the like.

  According to a third aspect of the present invention, there is provided a combustion state detection device according to the second aspect, in which the flame detection means includes a semiconductor optical sensor such as a photodiode or a phototransistor.

  According to the first aspect of the present invention, the presence or absence of flame is detected based on whether the output of the flame detection means is higher or lower than the reference level, and when the flame detection means has failed before the start of combustion, the flame before the start of combustion When the output of the detection means is in the presence of flame, or the output of the flame detection means after the start of combustion is in the state of no flame, it is determined that an abnormality has occurred in the flame detection means, and the reference level is set to the normal level during combustion. When the level is higher than the first level for judging whether or not there is a flame and is not normally reached but switched to the second level that is reached when there is an abnormality. It is determined that there is a possibility that an abnormality has occurred in the flame detection means during combustion, and once the combustion is stopped, the reference level is switched to the first level for determining the presence of the original normal flame. When the output is in flame Since it is determined that an abnormality has occurred in the flame detection means during combustion, even if the output of the flame detection means accidentally has a flame with respect to the reference level of the second level due to a temporary change in the flame during combustion, It is possible to reliably determine the occurrence of an abnormality in the flame detecting means during combustion by not stopping the combustion immediately but once stopping the combustion and checking the output of the flame detecting means again.

  According to the combustion state detection device of claim 2 of the present invention, in the combustion state detection device of claim 1, the flame detection means includes a sensor that outputs light by receiving flame light, The sensor uses the characteristic that the minute output increases as the temperature of the semiconductor optical sensor itself rises when it is not receiving light, and the output of the flame detection means consisting of the semiconductor optical sensor after combustion is stopped during combustion When the state is higher than the first level higher than the level output by the normal flame detection means after stopping for a predetermined time, it is determined that an abnormally high temperature has occurred due to exhaust gas leakage, etc. The abnormal temperature can be determined without the need for an abnormally high temperature detecting means for detecting the abnormally high temperature of the burner part due to leakage of the burner and the receiving side of the burner part and stopping the combustion operation. .

  According to the combustion state detection device of claim 3 of the present invention, in the combustion state detection device of claim 2, the flame detection means is a semiconductor optical sensor such as a photodiode or a phototransistor. This semiconductor optical sensor has a large characteristic that the minute output increases as the temperature of the semiconductor optical sensor itself rises when it is not receiving light, and is a flame detection means consisting of a semiconductor optical sensor after combustion is stopped after combustion. When the output is higher than the third level higher than the level output by the normal flame detection means after the combustion is stopped and the state continues for a predetermined time, it is easy to determine that an abnormally high temperature has occurred due to exhaust gas leakage or the like. An abnormally high temperature detection means is required to stop the combustion operation by detecting the abnormally high temperature of the burner part and the receiving side of the burner part due to exhaust gas leakage from the mounting part. It is intended to be more reliably to abnormal temperature determination without.

Next, an embodiment of the present invention will be described with reference to the drawings.
Reference numeral 1 denotes a burner part of a combustion device, in which vaporized fuel oil and combustion air are mixed and the mixture is burned.
Reference numeral 2 denotes a flame detection unit, which has a flame detection unit 3 whose output value changes depending on the presence or absence of a flame in the burner unit 1, and the flame detection unit 3 is a semiconductor optical sensor composed of a photodiode, a phototransistor, etc. The flame detection means 3 becomes hot when exhaust gas leaks from a burner mounting portion (not shown) for mounting the burner portion 1 of the combustion equipment, and the light that enters the flame sensor is the most when the burner portion 1 is in a combustion stopped state. It can be installed in a few positions.

  In addition, when the burner unit 1 is burning and there is a flame, the flame detection unit 2 has an output higher than the reference level due to the light of the flame, and when the burner unit 1 is not burning and there is no flame, the flame is detected. The output is lower than the reference level due to the absence of light.

  Reference numeral 4 denotes an abnormality determination unit, which includes a flame determination unit 5 and an abnormal temperature determination unit 6. The flame determination unit 5 compares the output from the flame detection unit 2 with a reference level, and the output of the flame detection unit 2 is a reference. When it is higher than the level, it is determined that the burner unit 1 is burning and there is a flame, and a flame presence signal is output. When the output of the flame detection unit 2 is lower than the reference level, the burner unit 1 is in a combustion stop state and the flame is It is determined that there is no flame, and a flameless signal is output.

  Further, the abnormal temperature determination unit 6 has a minute output that increases as the temperature of the semiconductor photosensor increases when the semiconductor photosensor such as a photodiode or phototransistor of the flame detection means 3 is not receiving light, Based on the minute output from the semiconductor optical sensor, an abnormally high temperature due to the leakage of exhaust gas from the combustion burner mounting portion is determined and an abnormally high temperature signal is output.

  7 is a control unit that controls the combustion of the burner unit 1, the presence / absence of flame in the burner unit 1 based on the output signal of the abnormality determination unit 4, the abnormality determination of the flame detection means 3 of the flame detection unit 2, and from the combustion burner attachment unit An abnormally high temperature judgment due to exhaust gas leakage is performed.

Next, flame determination will be described with reference to the flowchart shown in FIG.
First, since there is no flame in the combustion stop state, the output of the flame detector 2 is a low signal lower than the reference level, and the low signal output from the flame detector 2 is input to the flame determiner 5 of the abnormality determiner 4, As a result of the comparison with the reference level, the flame determination unit 5 determines that there is no flame and outputs a flameless signal to the control unit 7. (S1)

  At this time, the output of the flame detection means 3 of the flame detection unit 2 is a high signal higher than the reference level, and the high signal output from the flame detection unit 2 is input to the flame determination unit 5 of the abnormality determination unit 4 and the flame determination unit As a result of comparison with the reference level, when it is determined that there is a flame and a flame presence signal is output to the control unit 7, the control unit 7 determines that an abnormality has occurred in the flame detection means 3 of the flame detection unit 2 ( S2) The occurrence of abnormality in the flame detection means 3 is displayed on a display unit (not shown) in a state where combustion is stopped. (S3)

  In (S1), when the flame determination unit 5 compares with the reference level to determine that there is no flame and outputs a no flame signal to the control unit 7, the control unit 7 indicates that there is no flame and the flame detection unit 2 Is determined to be normal (S4), and combustion is started. (S5)

  When combustion is started, the output of the flame detection unit 2 changes from a low signal lower than the reference level to a high signal higher than the reference level, and the output from the flame detection unit 2 is input to the flame determination unit 5 of the abnormality determination unit 4. As a result of the comparison with the reference level, the flame determination unit 5 determines that there is a flame and outputs a flame presence signal to the control unit 7.

  The control unit 7 confirms whether a flame presence signal is output from the flame determination unit 5 (S6). If the flame determination signal is output from the flame determination unit 5, a predetermined time from the state until the combustion becomes stable is determined. After the elapse (S7), the reference level of the flame determination unit 5 is switched from the first level at the time of normal combustion set up to now to the second level of the abnormality determination level (S8), and the flame determination unit 5 detects the flame. It is determined whether the output of the unit 2 is lower or higher than the reference level which is the second level. As a result, the output of the flame detection unit 2 is a high signal higher than the reference level, and the flame determination signal from the flame determination unit 5 is the control unit 7. (S9), the control unit 7 determines that there is a possibility that an abnormality such as a short-circuit state has occurred in the flame detection means 3.

  In (S9), when it is determined that there is a possibility that an abnormality such as a short circuit has occurred in the flame detection means 3, after the combustion is stopped (S10) and a predetermined time elapses until the fire is completely extinguished ( S11), the reference level of the flame determination unit 5 is switched from the second level of the abnormality determination level to the first level during normal combustion (S12), and in (S1), the flame determination unit 5 uses the output of the flame detection unit 2 as a reference. It is determined whether the low signal is lower than the level. As a result, if a flameless signal is output from the flame determination unit 5 to the control unit 7, the output of the flame detection means 3 is temporarily set to the second level due to flame flickering or the like. It is determined that an abnormality has not occurred due to higher than the reference level (S4), and if a flame presence signal is output from the flame determination unit 5 to the control unit 7, the flame detection means 3 is informed during combustion. It is determined that an abnormality such as a short circuit has occurred. (S2)

  Even if combustion is started in the fork (S5), if the flame determination signal is not output from the flame determination unit 5 and the flameless signal continues to be output (S6), the control unit 7 is disconnected from the flame detection means 3. It is determined that an abnormality such as the above has occurred, the combustion is stopped (S10), and the process proceeds to (S11).

  At the fork (S9), when the output of the flame detection unit 2 is a low signal lower than the reference level and the flame determination unit 5 outputs a flameless signal to the control unit 7, the control unit 7 indicates that the flame detection means 3 is normal. Determination is made to switch the reference level of the flame determination unit 5 from the second level of the abnormality determination level to the first level during normal combustion (S13) and return to (S6).

Next, the abnormal temperature determination will be described with reference to the flowchart shown in FIG.
First, it is confirmed whether or not the combustion state is changed to the combustion stop state (S14), and after a predetermined time elapses in order for the flame to be completely extinguished (S15), the control unit 7 detects the abnormal temperature determination unit 6 of the abnormality determination unit 4. Check if an abnormal signal is output from. (S16)

  At this time, the abnormal temperature determination unit 6 uses the third level lower than the first level of the flame detection unit 2 and higher than the level output by the normal flame detection means 3 after the combustion is stopped as the reference level. The reference level is compared with the output of the flame detection unit 2 after a predetermined time has passed at (S15), and when the output of the flame detection unit 2 is higher than the reference level, the abnormal temperature determination unit 6 outputs an abnormal signal to the control unit 7 To do.

  When the abnormal signal is not output from the abnormal temperature determination unit 6 in (S16), the control unit 7 returns to (S14), and when the abnormal signal is output from the abnormal temperature determination unit 6, the sensor current during ignition and extinguishing In order to prevent malfunction due to changes in noise and malfunction due to noise mixing, it is checked whether the output of the abnormal signal from the abnormal temperature determination unit 6 continues for a predetermined time (S17). When the output of the abnormal signal does not continue for a predetermined time (S16) When the abnormal signal output continues for a predetermined time, it is determined that an abnormally high temperature has occurred due to an exhaust gas leak or the like (S18), and the abnormally high temperature is displayed on the display unit while combustion is stopped. It is. (S19)

  In addition, after the abnormality occurrence display of the flame detection means 3 in the flame determination and the abnormal high temperature occurrence display in the abnormal temperature determination, the combustion operation is prohibited until the abnormality occurrence is reset by repairing and checking the abnormality content. It is what is done.

  In the present embodiment, the abnormality determination unit 4 includes the flame determination unit 5 and the abnormal temperature determination unit 6. However, the present invention is not limited to this, and the abnormality determination unit 4 has the first level and the second level as reference levels. The first level and the second level are used when performing flame determination and flame detection means 3 abnormality determination, and the third level is used when performing abnormal temperature determination. In comparison, a flame presence signal, a flame absence signal, and an abnormality signal may be output to the control unit 7.

  As described above, the presence / absence of a flame is detected based on whether the output of the flame detection means 3 comprising a semiconductor optical sensor is higher or lower than the reference level, and when the flame detection means 3 has failed before the start of combustion, When the output of the flame detection means 3 is in a state where there is a flame, or the output of the flame detection means 3 after the start of combustion is in a state where there is no flame, it is determined that an abnormality has occurred in the flame detection means 3 and a reference is made during combustion. The level is switched to the second level that is higher than the first level for judging whether or not there is a normal flame and does not reach normally but reaches at the time of abnormality, and the output of the flame detection means 3 is flame at the switched reference level. When the condition is “Yes”, it is determined that there is a possibility that an abnormality has occurred in the flame detection means 3 during combustion, and the reference level is switched to the first level for determining whether or not the original normal flame is present once the combustion is stopped. The output of the flame detection means 3 is When it is present, it is determined that an abnormality has occurred in the flame detection means 3 during combustion. Therefore, the output of the flame detection means 3 is accidentally changed to a second reference level due to a temporary change in the flame during combustion. However, even if there is a flame, it is not immediately determined that there is an abnormality, but once the combustion is stopped and the output of the flame detection means 3 is checked again, the occurrence of an abnormality in the flame detection means 3 during combustion can be reliably determined. Is.

  Further, the semiconductor optical sensor utilizes the characteristic that the minute output increases as the temperature of the semiconductor optical sensor itself rises when it is not receiving light, so that the flame detection means 3 comprising the semiconductor optical sensor after the combustion is stopped after the combustion is stopped. When the output is higher than the third level higher than the level output by the normal flame detection means 3 after the combustion is stopped and the state continues for a predetermined time, it is determined that an abnormally high temperature has occurred due to exhaust gas leakage or the like. The abnormal temperature can be determined without the need for an abnormally high temperature detecting means for detecting the abnormally high temperature of the burner part and the receiving side of the burner part due to leakage of exhaust gas from the attachment part and stopping the combustion operation.

BRIEF DESCRIPTION OF THE DRAWINGS The schematic block diagram which shows the combustion state detection apparatus which attached | subjected one Example of this invention. The flowchart figure of the same flame determination. The flowchart figure of the abnormal high temperature determination.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Burner part 3 Flame detection means 2 Flame detection part 4 Abnormality determination part 7 Control part

Claims (3)

  Compare the output value from the flame detection unit with a flame detection means that changes the output according to the combustion state of the burner unit, and the reference value, and determine the presence or absence of flame based on the size judgment An abnormality determination unit having a flame determination unit for outputting a flame presence signal or no flame signal, a flame presence signal or a flame absence signal from the abnormality determination unit, and a combustion operation or a combustion stop state at that time A control unit that determines whether the combustion state and the flame detection means are normal or abnormal depending on whether they match or not, and the control unit determines the reference value of the flame determination unit during the combustion state to determine the presence or absence of flame The flame detection means switches from the first level reference value to a second level higher than the first level reached when the flame detection means is not normal and is abnormal, and the flame determination unit outputs the second level reference value and the flame detection unit. The value of the flame is compared with the When a flame presence signal is output and the flame detection means may have failed during the combustion state, the combustion operation is temporarily stopped and the fire is extinguished. Switching from the second level to the first level, the flame determination unit compares the first level reference value with the output value from the flame detection unit in the fire extinguishing state, and determines the presence or absence of flame based on the magnitude determination A combustion state detection device that determines that an abnormality has occurred in the flame detection means during a combustion state when a flame presence signal is output.   The flame detection means is provided with a sensor that outputs light by receiving flame light, and the abnormality determination unit outputs a normal flame detection means that is lower than the reference value of the first level of the flame detection unit and stops after combustion is stopped. The third level higher than the level to be used is set as a reference level, and the reference level of this third level is compared with the output of the flame detection unit after combustion is stopped. When the output of the flame detection unit is higher than the reference level, an abnormal signal is output. An abnormal temperature determining unit, and when the output of the abnormal signal from the abnormal temperature determining unit continues for a predetermined time, the control unit determines that an abnormally high temperature has occurred due to exhaust gas leakage around the burner unit. The combustion state detection apparatus according to claim 1, wherein   3. The combustion state detection device according to claim 2, wherein the flame detection means includes a semiconductor optical sensor such as a photodiode or a phototransistor.

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