JP2002031335A - Combustion detecting device and its detecting method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a combustion detecting device and its detecting method to be superior in workability during maintenance and inspection of a combustion device. SOLUTION: The combustion detecting device 32 comprises a detecting data memory part 34 to detect brightness of flame during combustion by an electrical means and storing electrically detected illuminance during non-combustion or during combustion; a detected data-comparing part 35 to compare illuminance during combustion, when stored illuminance is during non-combustion with illumination during non-combustion, when the stored one is during combustion; and a combustion deciding part 36 to decide non-combustion or combustion by a difference produced resultant from comparison by the detecting the data- comparing part.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a liquid fuel combustion system for domestic use, and more particularly to a combustion detection device for judging the presence or absence of combustion based on the brightness of a combustion flame of a water heater, a bath pot, and the like, and a detection method therefor.

[0002]

2. Description of the Related Art A conventional combustion detecting device and its detecting method will be described with reference to FIG. 3 which is a block diagram of a conventional combustion detecting device and a combustion device provided with the detecting method. 101 is a conventional combustion detection device and a combustion device provided with the detection method, and 1
Reference numeral 1 denotes an oil tank having a supply pipe for storing and supplying kerosene as fuel outside the combustion device 101 and 12 for supplying fuel from the oil tank 11 to the combustion device 101. A fuel pump 13 for sucking and pressurizing, 13 a nozzle for spraying the fuel pressurized by the fuel pump 12 in a combustion cylinder described later, 14 a sirocco fan and an electric motor for rotating the sirocco fan for burning the combustion device 101 A blower for supplying air, 15 is an igniter for generating a spark discharge by a high voltage and igniting a mixture of the fuel sprayed by the nozzle 13 and the combustion air supplied by the blower 14, and 16 is a nozzle for the nozzle 13 A combustion cylinder that efficiently mixes the sprayed fuel with the combustion air supplied by the blower 14 and burns the mixed air and fuel after the igniter 15 ignites; Reference numeral 7 denotes a detection unit provided in the combustion cylinder 16 and detected as an electrical value having a correlation with the brightness (illuminance) of the flame burning in the combustion cylinder 16 (for example, if CdS (cadmium sulfide cell) A flame detector 20 for detecting the resistance value or the voltage value in the case of a photovoltaic element); and 20 for exchanging heat energy of the flame burning when the combustion tube 16 of the combustion device 101 is inserted into a heated object such as water or air. A heat exchanger 21 intended to be used for hot water supply or heating by detecting the temperature of a non-heated material of the heat exchanger and controlling the start and stop of combustion of the combustion device 101 Reference numeral 22 denotes a furnace provided inside the heat exchanger 20, which is a combustion space of the combustion device 101.

[0005] Reference numeral 50 denotes a combustion control unit of the combustion device 101 described later and a control unit including a combustion detection device described later;
Is a combustion control unit that controls the drive units of the fuel pump 12, the blower 14, and the igniter 15 by the temperature detector 21 of the heat exchanger 20, and 52 is a detection unit that will be described later. A combustion detection device 53 including a data conversion unit, a combustion determination unit, and a safety control unit 53 is detection data for converting an electrical value correlated to the brightness of the flame detected by the flame detector 17 into a value that can be easily stored and determined. The conversion unit 56 is a combustion determination unit that determines whether or not combustion is occurring based on a result of comparing the detection data of the detection data conversion unit 53 with a value for determining whether or not combustion is stored therein, and 57 is a combustion determination unit. The determination as to whether or not combustion is taking place at 56 and the combustion controller 5
In the case where the combustion determination unit 56 cannot determine that the fuel is burning even though the combustion control unit 51 is in the combustion state depending on whether the combustion control unit 51 is in the combustion state or not in the combustion control unit 51, The safety control unit 40 instructs the combustion control unit 51 to stop the operation of the combustion device 101 for safety when the combustion determination unit 56 determines that combustion is performed despite the absence of the combustion device 10.
An operating unit 41 is provided integrally or remotely with the operating unit 40 and is capable of transmitting a signal by wire or wirelessly and operated by a user to start or stop the operation of the combustion device 101. An alarm generation unit that notifies the user of an alarm state by a buzzer, sound, display, or the like when the unit 58 instructs to stop driving.

Next, a description will be given of a flow chart showing the detection operation of the combustion detection device 52 of the combustion device 101 in FIG. For convenience of explanation, the description will be made on the assumption that the detection value of the flame detector 17 decreases when the illuminance increases, and the detection value increases when the illuminance decreases. The user turns on the operation start switch (not shown) of the combustion device 101 of the operation unit 40, and if the temperature of the temperature detector 21 is equal to or lower than the set temperature, the combustion operation of the combustion device 101 starts (step 31). First, the combustion control unit 51 drives only the blower 14 (step 32). Generally, this operation is called pre-purge (pre-scavenging), and the brightness is detected once by the flame detector 17 from immediately before the start of the pre-purge to the end of the pre-purge (step 33). In FIG. 4, the detection timing is set to pre-purge. The detected value Xpr at the time of pre-purge is determined by the combustion determination unit 56.
It is confirmed that the value exceeds the non-combustion reference value R1 stored in (3) (step 34). If Xpr is equal to or less than R1, it is determined that the flame detector 17 is short-circuited and has failed. The combustion determination unit 56 instructs the safety control unit 57 to generate an alarm in the alarm generation unit 41, and at the same time, causes the combustion control unit 51 to stop the operation (step 35).

If Xpr exceeds R1, it is determined that the operation is normal, and the drive of only the blower 14 is continued as it is until a predetermined prepurge time. When the prepurge time elapses, the prepurge is terminated (step 36), and ignition is performed. The discharge of the device 15 and the pressurization of the fuel by the fuel pump 12 after a short delay are started, whereby the combustion is started (step 37). After waiting for a predetermined time until the combustion starts and the combustion is stabilized (not shown, and usually at the time when the predetermined time has elapsed, the discharge of the ignition device is stopped), the flame detector 17 reduces the brightness of the burning flame. It is detected (step 38), and this detected value is set to Xb. It is confirmed that the detected combustion detected value Xb is equal to or smaller than the combustion reference value R2 stored in the combustion determination unit 56 (step 39). If Xb exceeds R2, the flame detector is detected. 17 is broken in the disconnection state, or the light receiving surface of the flame detector 17 is determined to be contaminated with soot, or the combustion state is poor and the illuminance is not increased to a specified level. , An alarm is generated by the alarm generation unit 41, and at the same time, the operation is stopped by the combustion control unit 51 (step 40).

If Xb is equal to or less than R2, it is determined that normal combustion is being performed, and combustion is continued and the process returns to step 38 again until the temperature detector 21 detects the set temperature (step 4).
1) During the combustion, it is constantly monitored that the combustion is continued in steps 38 and 39. When the temperature detector 21 detects the temperature equal to or higher than the set temperature in step 41, the combustion control unit 51 stops the combustion by stopping the supply of the fuel by the fuel pump 12 (step 42), and generally rotates only the blower 14 continuously. An operation called post-purge (post-scavenging) is started (step 43). The reason for performing the post-purge is that the unburned gas in the furnace 22
This is because the post-purge is completed by the normal combustion control unit and the post-purge is completed (step 44), and immediately after that, the brightness is detected by the flame detector 17. (Step 45). In FIG. 4, the detection timing is immediately after the post-purge, but may be any time from the step 43 of the start of the post-purge to immediately after the end of the post-purge. However, in general, immediately after the start of post-purge, the inside of the furnace 22 is glowing red due to residual heat during combustion, and the brightness cannot be accurately detected. The detected value immediately after the end of the post-purging is Xp
It is confirmed that the value exceeds the non-combustion reference value R1 stored in the combustion determination unit 56 as o (step 46). If Xpo is equal to or less than R1, it is determined that the flame detector 17 has failed in a short-circuit state. Then, the combustion determination section 56 instructs the safety control section 57 to cause the alarm generation section 41 to generate an alarm (step 47). If Xpo exceeds R1, the operation is terminated (step 48). After step 48, the temperature detector 2
When 1 becomes lower than the set temperature, the process returns to step 31 again.

[0007] As described above, the conventional combustion detecting device for detecting combustion based on the brightness of the flame determines whether the ignition, the non-ignition, or the combustion is performed according to a predetermined reference value corresponding to the brightness of the flame. It was to be determined whether the fire had ceased. Further, a flame as a safety confirmation means for confirming that combustion by fuel dropped into the combustion chamber is not continued during pre-purge before starting combustion or before and after post-purge after finishing combustion, or thereafter. In general, when a flame is confirmed, an alarm or the like is displayed and the combustion operation is terminated. Had become.

[0008]

However, the conventional combustion detecting apparatus and the conventional detecting method have the following problems. a. Since the combustion device is usually used by being incorporated in a furnace such as a water heater, a bath pot, a hot air heater, etc., light does not normally enter during non-combustion. However, in order to determine the combustion state of the combustion apparatus in maintenance and inspection of the combustion apparatus, it is necessary to take out the furnace from the furnace and check the combustion state (for example, the state of spot ignition or the state of flame). In such a case, the combustion detection device erroneously recognizes the brightness of the outside as burning, so that if the above-described safety confirmation means is performed during or before prepurge before starting combustion, an alarm is issued and the combustion is not started. There was a problem.

B. In addition, during post-purging after combustion is completed or when safety is checked afterwards, it is possible to perform maintenance and inspection without generating an alarm during external maintenance and inspection. There is a problem that an alarm is generated after the end of the post-purge.

C. There is also a method in which a warning is issued not at the end of combustion but at the start of next combustion, instead of the method b, in order to enhance the effect of alerting the user in actual use of the combustion device. According to this method, it is possible to perform maintenance and inspection without generating an alarm during external maintenance and inspection.However, in actual use, the flame detector that detects the flame temporarily fails and the flame is detected. If it is determined that the ignition is not performed, there is a problem that it is not possible to determine the misfire at the first time or the fire during the combustion, so that the supply of the fuel cannot be stopped.

An object of the present invention is to solve the above-mentioned conventional problems, and an object of the present invention is to provide a combustion detection device and a detection method thereof which do not impair safety while maintaining the convenience of maintenance and inspection outside the furnace.

[0012]

SUMMARY OF THE INVENTION A combustion detecting device according to the present invention detects the brightness of a flame during combustion by electric means,
A detection data storage unit that stores the electrically detected non-combustion or non-combustion illuminance, and compares the stored illuminance with the non-combustion illuminance when burning and the non-combustion illuminance when burning. A detection data comparison unit for performing the combustion, and a combustion judgment unit for judging non-combustion or combustion based on a difference compared by the detection data comparison unit. The illuminance detected at the time of non-combustion or combustion detected by means is stored, and the stored illuminance is compared with the illuminance at the time of combustion if it is non-combustion and the illuminance at the time of non-combustion if it is combustion Judging non-combustion or combustion based on the compared difference, and furthermore, during the non-combustion, during the prepurge performed before starting the combustion, immediately before the prepurge, and / or during the post-purge performed after the end of the combustion, or immediately after the post-purge. In It was made possible by.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a combustion detecting device and a detecting method according to the present invention will be described below with reference to the drawings. FIG. 1 is a configuration diagram of a combustion device for explaining a combustion detection device and a detection method thereof, and FIG. 2 is a flowchart for explaining the operation thereof. In the description of each part, the same parts as those in the conventional example are denoted by the same reference numerals, and description thereof will be omitted.

FIG. 1 is a block diagram of a combustion apparatus for explaining a combustion detection apparatus and a detection method according to the present invention. In FIG. 1, reference numeral 1 denotes a combustion apparatus provided with the combustion detection apparatus and a detection method according to the present invention; The control unit 31 includes a combustion control unit described below and a combustion detection device described below, and the control unit 31 includes:
The fuel pump 12, the blower 14, the igniter 15
And the like, a combustion control unit that controls the drive unit by the temperature detector 21 of the heat exchanger 20, a detection data conversion unit, a detection data storage unit, a detection data comparison unit,
A combustion detection device 33 including a combustion determination unit and a safety control unit 33 is a detection data conversion unit that converts an electrical value correlated with the brightness of the flame detected by the flame detector 17 into a value that can be easily stored and determined. Is a detection data storage unit that stores the detection values converted by the detection data conversion unit 33; 35 is a detection data comparison unit that compares values stored in the detection data storage unit 34; 36 is the detection data comparison unit 35 A combustion judging unit for judging whether or not combustion is taking place based on the result of the comparison in step 37;
The combustion determination unit 36 determines whether or not the combustion is being performed by the combustion determination unit 36 and the combustion control unit 31 determines whether or not the combustion is being performed. When it is not possible to determine that the combustion control unit 31 is burning, or when the combustion determination unit 36 determines that combustion is occurring even though the combustion control unit 31 does not set the combustion state, the combustion control unit 31 is used for safety. Is a safety control unit that instructs the combustion device 1 to stop operating.

Next, the combustion detection device 32 of the combustion device 1 shown in FIG.
This will be described with reference to a flowchart showing the detection operation.
The user turns on the operation start switch (not shown) of the combustion device 1 of the operation unit 40, and if the temperature of the temperature detector 21 is equal to or lower than the set temperature, the combustion operation of the combustion device 1 starts (step 1). First, the combustion control unit 31 drives only the blower 14 (step 2). Generally, this operation is called pre-purge, and the brightness is detected once by the flame detector 17 once immediately before the start of the pre-purge until the end of the pre-purge (step 3). In FIG. 2, the detection timing is set to pre-purge as in the conventional example. The detected value Xpr at the time of pre-purge is stored and converted into a value that facilitates subsequent determination and stored in the detected data storage unit 34 (step 4).

The driving of only the blower 14 is continued until a predetermined prepurge time, and when the prepurge time elapses, the prepurge is terminated (step 5), and the discharge of the ignition device 15 and the pressurization of the fuel by the fuel pump 12 after a short delay are performed. Then, the combustion is started (step 6). After waiting for a predetermined time until the combustion starts and the combustion stabilizes (not shown, and usually at the time when the predetermined time has elapsed, the discharge of the ignition device 15 is stopped). Is detected (step 7), and a detected value obtained by converting the detected brightness into a value that can be processed electrically is defined as Xb. The detected value Xb at the time of combustion is compared with Xpr stored in the detection data storage unit 34 and the detection data comparison unit 35.
To confirm that the change width is equal to or greater than the change width r stored in the combustion determination unit 36 (step 8). If Xpr-Xb is less than r, it is determined that no ignition has occurred, and the combustion determination unit 36 is safe. An instruction is issued to the control unit 37, an alarm is generated by the alarm generation unit 41, and at the same time, the operation of the combustion control unit 31 is stopped (step 9).

If Xpr-Xb is equal to or larger than r, it is determined that the combustion is normal, and the process returns to step 7 again until the temperature detector 21 detects the set temperature (step 10). Monitor for continued combustion. When the temperature detector 21 detects the temperature equal to or higher than the set temperature in step 10, the detected value Xb1 obtained by converting the brightness during combustion at that time is stored in the detected data storage unit 34 (step 11). The combustion is stopped by stopping the fuel supply (step 1).
2) An operation generally called post-purge, in which only the blower 14 is continuously rotated, is started (step 13).
The reason why the post-purge is performed is to discharge the unburned gas in the furnace 22 to the outside of the furnace 22, and the normal combustion control unit 31 stores a predetermined post-purge time, and the post-purge is completed. (Step 14) Immediately thereafter, the brightness is detected by the flame detector 17 (Step 15). In FIG. 2, as in the conventional example, the detection timing is immediately after the post-purge, but may be any time between the step 13 of starting the post-purge and the step 15 immediately after the end of the post-purge. However, in general, immediately after the start of post-purge, the inside of the furnace 22 is glowing red due to residual heat during combustion, and the brightness cannot be accurately detected. The detection value Xb stored in the detection data storage unit 34 as the detection value immediately after the end of the post-purge is stored as Xpo.
1 and the detection data comparison unit 35, and confirms that the difference is less than the change width r stored in the combustion determination unit 36 (step 16). If Xpo-Xb1 is less than r, the flame detector is activated. It is determined that a failure has occurred in the short-circuit state, and the combustion determination unit 3
6 instructs the safety controller 37 to cause the alarm generator 41 to generate an alarm (step 17). If Xpo-Xb1 is equal to or larger than r, it is determined that the operation is normal, and the operation is terminated (step 18). After step 18, if the temperature of the temperature detector 21 becomes lower than the set temperature, the process returns to step 1.

As described above, in the embodiment, the combustion detecting device and the detecting method thereof are configured, and thus have the following operations. a. The combustion detecting device according to claim 1, wherein the brightness at the time of combustion or non-combustion is stored, and the stored value is compared with non-combustion when the value is combustion, and compared with combustion when the value is non-combustion. Combustion and non-combustion are determined based on the difference between the values and a predetermined reference value. Therefore, it is possible to determine combustion or non-combustion even if the overall brightness standard is raised due to ambient brightness during maintenance and inspection. It has the action of: b. According to the second aspect of the present invention, in the combustion detection method, the brightness at the time of combustion or at the time of non-combustion is stored. Combustion or non-combustion is determined based on the difference between the values and a predetermined reference value. Therefore, it is determined that combustion or non-combustion occurs even if the overall brightness standard is raised due to ambient brightness during maintenance and inspection. Has the effect of being able to c. According to the third aspect, in addition to the function of the above a or b, there is an action of specifying a timing of detection during non-combustion.

[0019]

According to the present invention, it is possible to judge whether combustion or non-combustion is hardly affected by the surrounding brightness by the combustion detecting device and the detecting method thereof. The method is excellent in workability at the time of maintenance and inspection while maintaining the performance as a safety device. According to the second aspect, the method is excellent in workability at the time of maintenance and inspection while ensuring safety. This has the effect that the determination can be made more reliably.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a combustion detection device and a combustion device provided with the detection method according to the present invention.

FIG. 2 is a flowchart illustrating the operation of the present invention.

FIG. 3 is a configuration diagram of a conventional combustion device.

FIG. 4 is a flowchart illustrating a conventional operation.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1, 101 Combustion device 11 Oil tank 12 Fuel pump 13 Nozzle 14 Blower 15 Ignition device 16 Combustion cylinder 17 Flame detector 20 Heat exchanger 21 Temperature detector 22 Furnace 30, 50 Control part 31, 51 Combustion control part 32, 52 Combustion Detection device 33, 53 Detection data conversion unit 34 Detection data storage unit 35 Detection data comparison unit 36, 56 Combustion determination unit 37, 57 Safety control unit 40 Operation unit 41 Alarm generation unit

Claims (3)

[Claims] 1. A combustion detection device for detecting the brightness of a flame at the time of combustion by electric means, a detection data storage section for storing the illuminance at the time of non-combustion or at the time of combustion electrically detected, and If not burning, the illuminance during burning,
A combustion detection device comprising: a detection data comparison unit that compares the illuminance during non-combustion when burning; and a combustion determination unit that determines non-combustion or combustion based on a difference compared by the detection data comparison unit. . 2. A combustion detection device for detecting the brightness of a flame during combustion by an electric means, wherein the illuminance which is electrically detected during non-combustion or combustion is stored, and the stored illuminance is used during non-combustion. A method for detecting a combustion detection device, comprising comparing illuminance during combustion and illuminance during non-combustion during combustion, and determining non-combustion or combustion based on the difference. 3. The non-combustion state according to claim 1, wherein the non-combustion state is during pre-purge before starting combustion, immediately before the pre-purge, and / or during post-purge after completion of combustion, or immediately after the post-purge. A combustion detection device and a detection method thereof.