JP7421427B2 - combustion equipment - Google Patents

Description

The present invention relates to combustion equipment such as heating equipment and hot water supply equipment, and more particularly to a combustion equipment equipped with a function of detecting incomplete combustion in a combustion burner.

Conventionally, when the number of incomplete combustions detected by the flame rod voltage exceeds a predetermined number of times, an interlock state is established in which combustion is prohibited.

If the supply/exhaust system is an FF type, if indoor air is supplied/exhausted due to equipment abnormality such as a hole in the exhaust stack, the oxygen concentration in the room will decrease and incomplete combustion will occur. If it is detected multiple times, an interlock condition will occur and the operation will no longer be resumed. (For example, see Patent Document 1)

Patent No. 5647489

By setting the interlock state, operation is prohibited until inspection and repair are carried out by a repair company, so safety can be ensured. However, incomplete combustion detected by the flame rod detection level may The cause may be snow and ice stuck to the tip of the cylinder, and normal combustion can be restored by removing the snow and ice.
However, it cannot be distinguished from incomplete combustion caused by equipment abnormality, and even though it is possible to return to the normal state, the system remains in an interlock state, and combustion for space heating or hot water supply continues until inspection and repair is completed. However, there was a problem in that it was not possible to do this, which caused inconvenience to the user.

The present invention was made in view of this background, and the detection level of the flame rod decreases due to incomplete combustion caused by a malfunction in the supply and exhaust pipes, or failures caused by blockage of the supply and exhaust pipes such as ice in the supply and exhaust pipes. An object of the present invention is to provide a combustion device that can distinguish between a drop in the detection level of a flame rod due to complete combustion.

The present invention has been made to achieve the above object, and in claim 1, a combustion burner that performs combustion, a combustion fan that sends combustion air to the combustion burner, and a combustion flame of the combustion burner are detected. a first timer that starts counting combustion time when a detection level of the flame rod becomes less than a first detection level after the start of combustion; a second timer that starts counting the combustion time when the detection level becomes less than a second detection level that is smaller than the first detection level; and when the second timer exceeds a predetermined time A; error stopping means for stopping combustion of the combustion burner; and when the second timer exceeds a predetermined time A, or when the detection level of the flame rod becomes less than a second detection level, the error stopping means stops the combustion of the combustion burner; The present invention is characterized by comprising a combustion stoppage cause determining means for determining the cause of combustion stoppage based on whether or not a timer 1 is equal to or longer than a predetermined time B.

In claim 1 , after the start of combustion, when the detection level of the flame rod becomes below a third detection level which is a detection level higher than the first detection level, the rotation speed of the combustion fan is adjusted to a predetermined value. After that, when the detection level of the flame rod exceeds a fourth detection level that is higher than the third detection level, the rotation speed of the combustion fan is returned to the rotation speed before reducing the rotation speed by a predetermined percentage. The combustion fan is characterized by being equipped with a combustion fan correction control to restore the combustion fan.

In claim 2 , the combustion stoppage cause determination means determines whether or not there is incomplete combustion, and only when the combustion stoppage cause determination means determines that there is incomplete combustion, the number of incomplete combustion determinations is counted. The present invention is characterized in that it has an incomplete combustion number storage unit that stores the number of incomplete combustions, and performs an interlock when the number of incomplete combustions stored in the incomplete combustion number storage unit is equal to or greater than a first number of times.

In claim 3 , an operating section is provided on the main body of the combustion device or in a place other than the main body, and when combustion is stopped, an error display is displayed on the operating section using a predetermined error code, and the user is informed of the cause of stopping combustion. The invention is characterized in that it further comprises a notification means to the effect that the combustion is stopped for a predetermined period of time C from the combustion stop when the number of incomplete combustions stored in the incomplete combustion number storage section is equal to or greater than a second number of times which is less than the first number of times. The present invention is characterized in that the notification for displaying the error is not canceled until the period of time has elapsed.

According to claim 1, the first timer is started when the detection level of the frame rod decreases and becomes less than the first detection level, and when the detection level of the frame rod becomes less than the second detection level, the first timer is started. starts a timer, and when the second timer reaches a predetermined time A or more, or when the detection level of the frame rod becomes less than the second detection level, the first timer starts a predetermined time B or more. The cause of combustion stoppage is determined based on whether or not there is a drop in the detection level of the flame rod, so the detection level is determined to be due to incomplete combustion caused by blockage of the supply and exhaust pipes such as freezing or soot clogging. It is possible to detect incomplete combustion in a combustion burner by distinguishing between a drop in the detection level due to incomplete combustion caused by falling of the air supply and exhaust stack, abnormal construction of equipment, and malfunction of maintenance.

According to the first aspect, incomplete combustion in the combustion burner can be detected by the combustion fan correction control, by more clearly distinguishing whether the cause is blockage of the supply/exhaust pipe or falling of the supply/exhaust pipe. This is due to the following reason.
If combustion continues with the supply and exhaust pipes falling off, the oxygen concentration in the room decreases, the combustion rate decreases and unburned gas is generated, causing the combustion to tend to lift, and the detection level of the flame rod gradually decreases. After that, when the rotation speed of the combustion fan is lowered, the lift is reduced and the detection level of the frame rod tends to recover. After that, when the rotational speed of the combustion fan is restored, the detection level of the flame rod drops again.
On the other hand, if combustion continues with the intake and exhaust pipes blocked, the intake path will lack air, which will disrupt combustion and lower the detection level of the flame rod. Thereafter, when the rotational speed of the combustion fan is reduced, the intake air shortage accelerates, and the detection level of the flame rod further decreases, reaching the second detection level in a relatively short time.
Therefore, according to claim 1 , the detection level is lowered due to incomplete combustion caused by blockage of the supply and exhaust pipes, such as freezing or soot clogging, or falling of the supply and exhaust pipes and equipment construction abnormalities or poor maintenance. Incomplete combustion in the combustion burner can be detected by more clearly distinguishing whether the detection level has fallen due to incomplete combustion caused by a malfunction.

According to claim 2 , incomplete combustion of the combustion burner is likely to occur due to falling air supply and exhaust pipes, construction abnormalities, installation outdoors with an enclosure and lack of ventilation, etc. Continuing combustion of the combustion burner in an inappropriate usage state can be prohibited by setting the interlock state.

According to claim 3 , an operating section is provided on the main body of the combustion device or at a location other than the main body, and when combustion is stopped, an error display is displayed on the operating section using a predetermined error code, and the cause of the combustion stoppage is displayed to the user. Since the apparatus is provided with a notification means for notifying the user of the stoppage, an error code can be displayed on the operation section or a notification can be made using a speaker, and the user can be notified of the cause of the stoppage. In addition, before entering the interlock state, the user is notified at the timing of the error display that a similar event has already occurred repeatedly and that the device may become unable to continue to be used due to the interlock state in the future. It is possible to reliably encourage equipment inspection and repair services.

A schematic configuration diagram showing an example of combustion equipment according to an embodiment of the present invention Electrical circuit diagram of essential parts of the present invention Flowchart showing abnormality detection means of the present invention Flowchart showing combustion fan correction control of the present invention An explanatory diagram showing the transition of the detection level of the frame rod during abnormality detection of the present invention

A combustion device according to an embodiment of the present invention will be described with reference to FIGS. 1 to 5.
Note that, in each figure, common components and components of the same type are denoted by the same reference numerals, and overlapping explanations thereof will be omitted as appropriate.

As shown in Fig. 1, 1 is a combustion engine that exchanges heat with indoor air by blowing air into a heat exchanger 2 heated by combustion gas inside with a convection fan 3, and then releases warm air into the indoor space from an outlet 4. It is a device.

Reference numeral 5 indicates a double-pipe structure including an air supply pipe 7 that is installed through a wall 6 and takes in outdoor air into the interior, and an exhaust pipe 9 that discharges low-temperature combustion gas that has been heat exchanged in the heat exchanger 2 to the outside. This is an air supply/exhaust pipe, and 10 is a combustion fan that blows outdoor air taken in by the air supply pipe 7 into the combustion tube 11 as combustion air.

Reference numeral 12 denotes an oil leveler that stores fuel at a constant oil level, which pumps up the fuel with an electromagnetic pump 13 and supplies it from a supply pipe 14 to a vaporizer 15 located at the lower part of the combustion cylinder 11.

Reference numeral 17 denotes a pot thermistor consisting of a temperature sensor attached to the back surface of the bottom of the vaporizing section 15, and when the temperature inside the vaporizing section 15 is monitored and preheating or heating operation is required, it is connected to a pot heater 18 consisting of a rod-shaped ceramic heater. By issuing an instruction, the inside of the vaporizing section 15 is brought to an appropriate temperature.

Reference numeral 19 denotes a combustion burner located at the lower part of the combustion tube 11 and having a vaporizing section 15 installed at the bottom.The fuel oil gasified in the vaporizing section 15 and combustion air are mixed uniformly and ignited to perform combustion. Exhaust gas.

Reference numeral 20 denotes a flame rod installed so as to touch the flame generated by the combustion burner 19, and detects the flame rod voltage generated by the current flowing through the flame, and based on the detection level, determines whether there is an ignition error, a misfire midway, or a lack of oxygen. This system determines whether there is an abnormality or the like and stops combustion.

Indoor air taken into the combustion equipment 1 by the convection fan 3 is heated by the heat exchanger 2 and turned into warm air, which is discharged indoors from the outlet 4.

Next, an electric circuit diagram of the main part of this embodiment will be explained using FIG. 2.
22 is a control unit consisting of a microcomputer equipped with a CPU, memory, timer, input/output circuit, etc. and installed below the heat exchanger 2, and 23 is an operation switch for instructing the start and end of combustion operation.

24 is a flame detection circuit that outputs the flame rod detection level detected by the flame rod 20 to the control section 22. Further, a pot thermistor 17 is connected to the input side, and outputs the result of detecting the temperature of the vaporizing section 15 to the control section 22 .

Reference numeral 25 denotes a drive unit that controls the drive components, and receives the output from the control unit 22 to turn on and off the power to the pot heater 18.

Reference numeral 27 denotes a display unit connected to the output side of the control unit 22, which is located near the operation unit 40, receives the output from the control unit 22, displays the time, room temperature, set temperature, etc., and also detects the frame rod. Displays an error indicating that the level is abnormal.

Next, the operation of this combustion equipment will be explained according to FIGS. 3 to 5.
First, in S1 of FIG. 3, combustion fan correction control is performed as the detection level of the flame rod 20 that detects the combustion flame of the combustion burner 19 falls.
As shown in S19 of FIG. 4 and FIG. Adjust the combustion fan rotation speed R to a rotation speed reduced by ▲3%.

The subsequent combustion fan correction control will be explained separately for the (former) state in which the supply and exhaust pipe has fallen off, and (the latter) state in which the supply and exhaust pipe is blocked.
In the former case, when the supply and exhaust pipe falls off, the lift of the combustion flame is reduced by reducing the rotational speed of the combustion fan in S20, so the situation is as shown in the curve graph (broken line part) of A supply and exhaust pipe falling off in Fig. 5. , the flame rod voltage tends to recover. Next, when the frame rod voltage V exceeds 4.5V in S21, the combustion fan rotation speed R is returned to the initial rotation speed in S22. As a result, assuming that there is no change in the state in which the supply and exhaust pipes have fallen off, the frame rod voltage V drops again. Through S23 and S24, the processes from S19 to S22 are repeated a designated number of times, and the combustion fan correction control S1 is ended.
The latter state in which the supply and exhaust pipes are blocked is shown in the curve graph of B supply and exhaust pipe blockage in Figure 5, because even if the combustion fan rotation speed is reduced in S20, the intake path will be short of air and combustion will collapse. As such, the flame rod voltage V drops without recovering. Then, the combustion fan correction control S1 is ended by the determination in S25.

The above combustion fan correction control determines whether (the former) the voltage drop is due to incomplete combustion caused by blockage of the supply/exhaust pipe such as ice or soot clogging, or (the latter) the fall of the supply/exhaust pipe and abnormal installation of the equipment. It is possible to widen the time difference between the voltage drop between the former and the latter, making it possible to more clearly distinguish between the two based on the voltage drop time.

Next, in S2 to S3, when the frame rod voltage V further decreases to less than 4.0V, the first timer is started.
Then, in S4 to S5, when the frame rod voltage V further drops to less than 3.5V, a second timer is started.
Further, when the second timer reaches 180 seconds or more, the error stop means stops energizing the electromagnetic pump 13, pot heater 18, convection fan 3, and combustion fan 10 to stop the combustion burner.

In S8, if the thermal power at the time the combustion burner is stopped is less than the predetermined thermal power, the process branches to S9, and if it is greater than the predetermined thermal power, the process branches to S10.
As a result, as will be described later, when the firepower is relatively large, the temporal change in flame rod voltage makes it difficult to distinguish between a blockage of the supply and exhaust pipes and incomplete combustion due to the supply and exhaust pipes falling off, and If the same threshold value is applied to the case where the thermal power is less than

In S9, if the first timer is 1200 seconds or more (A supply/exhaust pipe falling off in Fig. 5), incomplete combustion is determined to be due to falling of the supply/exhaust pipe, equipment construction abnormality, or maintenance failure. In S10, notification is made to display an error code. Thereby, it is possible to reliably inform the user of the cause of the stoppage of combustion.
If the first timer is less than 1200 seconds (B supply and exhaust pipe blockage in Fig. 5), incomplete combustion is determined to be caused by blockage of the supply and exhaust pipe, such as freezing or soot clogging in the supply and exhaust pipe. The process moves to S17, where an error code is displayed indicating that the fire was extinguished during the process, and the operation is stopped at S18.

In S11, the number of occurrences of incomplete combustion is counted up, and in S12 it is determined whether the number of occurrences is greater than or equal to the specified number of occurrences. If the number of occurrences is greater than or equal to the second number, the incomplete combustion prevention error notified in S13 is displayed for a predetermined time C. During this period, processing will not be canceled. As a result, prior to entering the interlock state, a similar event has already occurred repeatedly, and the device may become interlocked in the future and may no longer be able to be used, at the timing of the error display. It is possible to reliably encourage users to perform equipment inspection and repair services.
Then, in S14, the display of the incomplete combustion prevention error can be canceled.

The number of occurrences of incomplete combustion is determined in S15, and if it is less than the first number, the process moves to S18, and if it is the first number or more, an interlock state is entered in S16.
This may result in cases where incomplete combustion of the combustion burner is likely to occur due to falling air supply and exhaust pipes, abnormal construction, insufficient ventilation due to installation outdoors with an enclosure, or where the equipment is not being used properly. Continuation of combustion in the combustion burner in an appropriate state can be prohibited by creating an interlock state.

As another embodiment, when combustion starts and the flame rod voltage V drops to less than 4.0 V after the combustion fan correction control, the first timer is started, and the flame rod voltage V 2, that is, when the flame rod voltage V becomes less than 3.5V, determine whether the first timer is 1020 seconds (=1200 seconds - 180 seconds) or more, If the first timer is 1020 seconds or more, it may be determined that there is an incomplete combustion prevention error, and if the first timer is less than 1020 seconds, it may be determined that there is an intermediate extinguishing error.

Note that the other configurations used in this embodiment are presented as examples, and are not intended to limit the scope of the invention, and may be implemented in various other forms. Various omissions, substitutions, and changes can be made without departing from the gist of the invention. These embodiments and their modifications are included within the scope and gist of the invention, as well as within the scope of the invention described in the claims and its equivalents.

1 Combustion equipment 10 Combustion fan 19 Combustion burner 20 Flame rod 40 Operation section 41 Incomplete combustion number storage section

Claims (3)

A combustion burner that performs combustion;
a combustion fan that sends combustion air to the combustion burner;
a flame rod that detects the combustion flame of the combustion burner;
a first timer that starts counting combustion time when the detection level of the flame rod becomes less than a first detection level after the start of combustion;
a second timer that starts counting the combustion time when the detection level of the flame rod becomes less than a second detection level that is smaller than the first detection level after the start of combustion;
error stopping means for stopping combustion of the combustion burner when the second timer reaches a predetermined time A or more;
When the second timer has exceeded the predetermined time A, or when the detection level of the frame rod has become less than the second detection level, whether the first timer has exceeded the predetermined time B. Combustion stoppage cause determination means for determining the cause of combustion stoppage based on whether or not the combustion stoppage occurs .
After the start of combustion, when the detection level of the flame rod becomes below a third detection level which is a detection level higher than the first detection level,
reducing the rotation speed of the combustion fan by a predetermined percentage;
Thereafter, when the detection level of the frame rod exceeds a fourth detection level that is higher than the third detection level,
Combustion fan correction control for returning the rotation speed of the combustion fan to the rotation speed before reducing the rotation speed by a predetermined percentage;
A combustion device characterized by being equipped with . The combustion stoppage cause determining means determines whether or not there is incomplete combustion;
The combustion stoppage cause determination means counts the number of incomplete combustion determinations only when the combustion stoppage cause determination means determines that the combustion is incomplete;
comprising an incomplete combustion number storage unit that stores the number of incomplete combustions;
The combustion equipment according to claim 1, wherein an interlock is performed when the number of incomplete combustions stored in the incomplete combustion number storage unit is a first number or more. An operating section is provided on the main body of the combustion equipment or at a location other than the main body,
displaying an error on the operating section using a predetermined error code when combustion is stopped;
Further comprising a notification means for notifying the user of the cause of the combustion being stopped,
The notification means is configured to: when the number of incomplete combustions stored in the incomplete combustion number storage unit is equal to or greater than a second number of times, which is smaller than the first number of times;
It is assumed that the notification that displays the error is not canceled until a predetermined time C has elapsed since the combustion stopped.
The combustion equipment according to claim 2 , characterized in that:

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