JP3021811B2 - Incomplete combustion prevention device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for preventing incomplete combustion of a gas-fired device based on the detection of carbon monoxide (CO) concentration by a CO sensor.

[0002]

2. Description of the Related Art Conventionally, in order to prevent incomplete combustion of gas combustion equipment which causes carbon monoxide poisoning, a CO sensor is provided in an exhaust pipe downstream of a gas burner, and a gas sensor is provided in accordance with a detection signal of the CO sensor. Safety devices for stopping combustion are known. For example, there is a safety device for a gas combustor proposed in JP-A-2-150618. This device issues an alarm by blinking a lamp or the like when the CO concentration detected by the CO sensor becomes equal to or higher than the alarm concentration based on a preset stop concentration and an alarm concentration lower than the stop concentration,
Thereafter, when the CO concentration equal to or higher than the stop concentration is detected, the gas supply to the gas burner is stopped.

[0003] In general, as a mechanism of generating carbon monoxide poisoning, there is a mechanism by exhaust gas recirculation. In exhaust gas recirculation, exhaust gas from a gas combustion device leaks into a room where the combustion device itself is installed, thereby lowering the oxygen concentration in the room and causing incomplete combustion to generate a large amount of CO. In addition, even when exhaust gas is completely discharged from the combustion equipment installation room, low-level CO can be generated due to the aging and combustion products adhering to the heat exchanger and exhaust stack of the combustion equipment. is there. Therefore, in the above-described conventional apparatus, it is possible to set a stop concentration and an alarm concentration, not only to prevent an accident due to exhaust gas recirculation, but also to notify a user of a time of removal of combustion products by an alarm, The safety and usability were high.

[0004]

However, as shown in FIG. 5, due to a poor connection of the exhaust pipe P or the like, the exhaust gas is exhausted from the other chamber R.
Is leaked to the sensor C detected by the CO sensor S
Even when the O concentration is at a low level, if the combustion is continued for a long time and the exhaust gas is discharged, the CO concentration in the other room R will increase. Although there is no problem if the user stops the device based on the alarm detecting the low level of the CO concentration, a high CO concentration will result if the user continues to use the alarm ignoring the alarm. An object of the present invention is to solve the above-mentioned problems and to provide an incomplete combustion prevention device having high safety performance against CO outflow to another room due to a defect in exhaust equipment or the like.

[0005]

In order to solve the above-mentioned problems, an incomplete combustion preventing apparatus according to the present invention is provided with a CO sensor provided in an exhaust passage of a gas burner for detecting a CO concentration in exhaust gas, as shown in FIG. M1 is compared with an opening / closing means M2 for opening and closing a gas supply passage to the gas burner, and the detected CO concentration is compared with a preset first reference concentration, and the CO concentration exceeds the first reference concentration. Alarm means M3 for issuing an alarm when the detected CO concentration is compared with a second reference concentration higher than the first reference concentration, and when the CO concentration exceeds the second reference concentration, the opening / closing is performed. by means M2 and the first stop means M4 for stopping the gas supply to the gas burner, with the warning is issued by the warning means M3, when the combustion by the gas burner continues for a predetermined time period, the CO concentration Without exceeding the second reference density
The gist of the invention is that a second stopping means M5 for stopping the gas supply to the gas burner by the opening / closing means M2 is also provided.

[0006]

In the incomplete combustion preventing apparatus according to the present invention having the above-mentioned structure, the CO sensor M1 detects the CO concentration in the exhaust gas from the gas burner, and when the concentration exceeds the first reference concentration, the alarm means M3 issues an alarm. . And, by exhaust gas recirculation etc.
If the O concentration rises and exceeds the second reference concentration, the first stopping means M4 operates the opening / closing means M2 to close the gas supply passage to the gas burner and stop the gas supply. Further, when the combustion by the gas burner continues for a predetermined period in a state where the alarm is issued because the CO concentration exceeds the first reference concentration, the second stopping means M5 operates the opening / closing means M2 to stop the gas supply. Let it. As a result, even if the CO concentration is at a low level, the gas supply is stopped if the combustion after the alarm is continued for a predetermined period of time. CO outflow stops.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In order to further clarify the configuration and operation of the present invention described above, a preferred embodiment of the incomplete combustion prevention device of the present invention will be described below. FIG. 2 is a schematic configuration diagram in which the incomplete combustion device as one embodiment is applied to an instantaneous water heater.

Case 10 for forming a combustion chamber of an instantaneous water heater
A gas burner 11 is provided at a lower portion of the fuel cell, and fuel gas is supplied from a gas supply source side through a gas supply path 14 having a main solenoid valve 12 and a proportional solenoid valve 13 arranged in series. The original solenoid valve 12 is a valve that only opens and closes the gas flow path, and the proportional solenoid valve 13 is a control valve that is set to an opening degree in accordance with a control signal and adjusts a desired gas supply amount. Case 10
A fan 15 is provided at the bottom of the case 10 to supply combustion air in an amount corresponding to the gas supply amount into the case 10.

A heat exchanger 16 is disposed above the gas burner 11, and the water passed through a water supply pipe 17 is supplied to the gas burner 1.
It is heated by the heat of combustion in 1 and sent out to the hot water supply pipe 18. The upper part of the case 10 above the heat exchanger 16 has a hood 19
Through the exhaust pipe 20. And this exhaust stack 2
A CO sensor 21 for detecting the CO concentration at 0 is mounted.

A front panel (not shown) of the instantaneous water heater
Is provided with a display 22 for issuing an alarm when the CO concentration reaches a predetermined concentration (a first reference concentration described later). In this embodiment, a blinking type display is used.
An alarm buzzer may be used, or both may be combined.

The apparatus for preventing incomplete combustion according to the present embodiment uses the C
Based on the signal from the O sensor 21, the solenoid valves 12, 13
The burner controller 23 is provided in the main body of the instantaneous water heater. The burner controller 23 also performs hot water temperature control, ignition control, and the like, but is not directly related to the present invention, and thus has a configuration accompanying these processes, such as a temperature sensor and a flow sensor. Description and illustration of the ignition device and the like are omitted.

The burner controller 23 includes a CPU, a RAM, and a ROM constituting an arithmetic and logic operation circuit (not shown);
The microcomputer is provided with a drive circuit, an input / output interface, and the like. The microcomputer receives a detection signal from the CO sensor 21 and operates according to the detected CO concentration.
To control the opening and closing of the gas flow path.

FIG. 3 is a flowchart showing an incomplete combustion prevention control routine executed by the burner controller 23, and is started in accordance with the ignition operation. When this routine starts, first, the signal of the CO sensor 21 is read and the CO
It is determined whether the density is equal to or higher than the first reference density C1 (S1).
0). This process is continued while the CO concentration is low and does not reach the first reference concentration C1. When the CO concentration becomes equal to or higher than the first reference concentration C1 due to exhaust gas recirculation or clogging of the fins of the heat exchanger 16 and the exhaust stack 20 due to combustion products, the display 22 is turned on and off, and an alarm is issued to the user. Is activated (S11).

Next, the CO concentration becomes equal to the second reference concentration C2 (C2
> C1) or not (S12), and if it is equal to or higher than the second reference concentration C2, the electromagnetic valves 12 and 13 are closed to stop the appliance (S13). At the same time, the timer is reset, and the blinking of the display 22 on which the alarm is displayed is stopped.

If it is determined in step 12 that the CO concentration is less than the second reference concentration C2, it is determined whether or not the time has elapsed, that is, whether or not a predetermined period T has elapsed since the alarm was issued. (S14) If the time has not expired, the flow shifts to the processing of step 12.

That is, in this incomplete combustion prevention control processing, as shown in FIG. 4, the CO concentration increases and the first reference concentration C1
Is reached, an alarm is issued by the display 22. If the appliance is used continuously, the CO concentration directly increases due to exhaust gas recirculation and the second reference concentration as shown in FIG. When the temperature reaches the second reference concentration C2, the appliance is stopped when the second reference concentration C2 is not reached due to the adhesion of combustion products or the like, as shown in FIG. Stops the appliance.

As a result, not only can the time of removal of the combustion products be recognized by the alarm, but even if the user ignores the alarm and continuously uses the apparatus, if the CO concentration becomes high, the apparatus is stopped and the CO concentration becomes low. However, since the equipment is stopped after the elapse of the predetermined period T in consideration of the outflow of CO to another room due to defective exhaust equipment or the like, the safety is extremely high not only in the equipment installation room but also in the other room.

The embodiments of the present invention have been described above.
The present invention is not limited to these examples in any way,
It goes without saying that the present invention can be implemented in various modes without departing from the gist of the present invention.

[0019]

As described above, the incomplete combustion prevention device of the present invention stops the gas supply when a predetermined period has elapsed with an alarm being issued, so that only the room where the combustion equipment is installed is provided. In addition, it is possible to cope with the outflow of CO to other rooms due to defective exhaust equipment and the like, and has an excellent effect of having extremely high safety performance.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a basic configuration of the present invention.

FIG. 2 is a schematic configuration diagram in which an incomplete combustion prevention device as one embodiment is applied to an instantaneous water heater.

FIG. 3 is a flowchart illustrating an incomplete combustion prevention control routine.

FIG. 4 is an operation explanatory view of the incomplete combustion prevention device.

FIG. 5 is an explanatory diagram showing a defective state of the exhaust equipment.

[Explanation of symbols]

Reference numeral 10: case, 11: gas burner, 12: original solenoid valve, 1
3: proportional solenoid valve, 14: gas supply path, 20: exhaust cylinder, 2
1: CO sensor, 22: Display, 23: Burner controller

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) F23N 5/24 107 F23N 5/00 F23N 5/26 101

Claims (1)

(57) [Claims] 1. A CO sensor provided in an exhaust passage of a gas burner for detecting a CO concentration in exhaust gas, opening / closing means for opening / closing a gas supply passage to the gas burner, and setting the detected CO concentration in advance. An alarming means for comparing the CO concentration with the first reference concentration and issuing an alarm when the CO concentration exceeds the first reference concentration; and detecting the detected CO concentration and a second reference concentration higher than the first reference concentration. A first stop means for stopping the supply of gas to the gas burner by the opening / closing means when the CO concentration exceeds the second reference concentration; and when the combustion by continues for a predetermined time period, the CO
Even if the concentration does not exceed the second reference concentration , the gas supply to the gas burner is stopped by the opening / closing means.
An incomplete combustion prevention device comprising a stopping means.