JPH0526440A - Incomplete combustion preventing device - Google Patents

Abstract

PURPOSE:To obtain highly safe performance against flowout of CO to other chamber due to a defect of an exhaust facility, etc., by stopping supply of gas if a predetermined time is elapsed in a state that an alarm is issued. CONSTITUTION:CO concentration in exhaust gas of a gas burner is detected by a CO sensor M1, warning means M3 outputs an alarm when the concentration exceeds a first reference concentration. If the concentration rises as it is due to recirculation of the exhaust gas, etc., to exceed a second reference concentration, first stop means M4 operates switching means M2 to close a gas supply passage thereby to stop supply of gas to the burner. If combustion is continued by the burner for a predetermined period in a state that the concentration exceeds the first reference concentration to output the alarm, second stop means M5 operates the means M2 to stop the supply of the gas. As a result, even if CO is fed to other chamber due to a defect of an exhaust facility, etc., the flowout of the CO is stopped in a safe period.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an incomplete combustion prevention device for stopping combustion of a gas combustion device based on 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 a gas combustion device that causes carbon monoxide poisoning, a CO sensor is provided in an exhaust stack downstream of a gas burner, and a gas is detected according to a detection signal from the CO sensor. Safety devices for stopping combustion are known. For example, there is a safety device for a gas combustor proposed in Japanese Patent Laid-Open No. 2-150618. This device gives an alarm by blinking a lamp or the like when the CO concentration detected by the CO sensor is equal to or higher than the alarm concentration based on a preset stop concentration and an alarm concentration lower than the stop concentration.
After that, when the CO concentration higher than the stop concentration is detected, the gas supply to the gas burner is stopped.

Generally, a mechanism of carbon monoxide poisoning is due to exhaust gas recirculation. In the exhaust gas recirculation, the exhaust gas from the gas combustion device leaks into the room in which the combustion device itself is installed, so that the oxygen concentration in the room decreases, causing incomplete combustion to generate a large amount of CO. Further, even when exhaust gas is completely discharged from the installation chamber of the combustion equipment, combustion products may adhere to the heat exchanger of the combustion equipment or the exhaust stack due to aging and generate low level CO. is there. Therefore, in the above-mentioned conventional device, not only can the stop concentration and the alarm concentration be set to prevent accidents due to exhaust gas recirculation, but also the alarm can notify the user of the timing of removal of combustion products, It was safe and easy to use.

[0004]

However, as shown in FIG. 5, the exhaust gas is discharged from the other chamber R due to a defective connection of the exhaust pipe P or the like.
If it leaks to C,
Even if the O concentration is at a low level, if the combustion is continued for a long time and the exhaust gas is released, the CO concentration in the other room R becomes high. There is no problem if the user stops the equipment based on the alarm that detects the low level CO concentration, but if the alarm is ignored and the device is used continuously, the CO concentration becomes high. An object of the present invention is to solve the above problems and to provide an incomplete combustion prevention device having high safety performance against CO outflow to another room due to defective exhaust equipment or the like.

[0005]

In order to solve the above problems, the incomplete combustion preventing device of the present invention is, as illustrated in FIG. 1, provided in an exhaust passage of a gas burner and is a CO sensor for detecting the CO concentration in the exhaust gas. M1 and opening / closing means M2 for opening / closing the gas supply passage to the gas burner are compared with the detected CO concentration and a preset first reference concentration, and the CO concentration exceeds the first reference concentration. In the case where the CO concentration exceeds the second reference concentration, the alarm means M3 for issuing an alarm is compared with the detected CO concentration and the second reference concentration higher than the first reference concentration. With the first stopping means M4 for stopping the gas supply to the gas burner by the means M2 and the warning by the warning means M3, when the combustion by the gas burner continues for a predetermined period, the opening / closing means M2. And gist that a second stop means M5 to stop the further gas supply to the gas burner.

[0006]

In the incomplete combustion prevention device of the present invention having the above-mentioned structure, the CO sensor M1 detects the CO concentration in the exhaust gas of the gas burner, and when this concentration exceeds the first reference concentration, the alarm means M3 gives an alarm. .. Then, by exhaust gas recirculation, etc., C
When the O concentration rises as it is 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. When the CO concentration exceeds the first reference concentration and an alarm is issued, and the combustion by the gas burner continues for a predetermined period, the second stop means M5 operates the opening / closing means M2 to stop the gas supply. Let As a result, even if the CO concentration is at a low level, the gas supply is stopped if the post-alarm combustion is continued for a predetermined period of time, so it is a safe time even if CO flows to another room due to defective exhaust equipment or the like. The CO outflow stops at that time.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In order to further clarify the structure and operation of the present invention described above, preferred embodiments of the incomplete combustion preventing device of the present invention will be described below. FIG. 2 is a schematic configuration diagram in which an incomplete combustion apparatus as one example 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 in the lower part of the fuel gas, and the fuel gas is supplied from a gas supply source side by a gas supply passage 14 having a source 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 according to a control signal and adjusts to a desired gas supply amount. Also, the case 10
A fan 15 is provided at the bottom of the case 10 to supply the combustion air into the case 10 in an amount corresponding to the gas supply amount.

A heat exchanger 16 is arranged above the gas burner 11, and water passed through the water supply pipe 17 is supplied to the gas burner 1.
It is heated by the heat of combustion in 1 and sent 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 is attached to 0.

The front panel of the instant water heater (not shown)
Is provided with a display 22 for issuing an alarm when the CO concentration reaches a predetermined concentration (a first reference concentration described later). Although a flashing type display is used in this embodiment,
A configuration using an alarm buzzer or a combination of both may be used.

The incomplete combustion prevention device of this embodiment has the C
Based on the signal from the O sensor 21, the solenoid valves 12, 13
The burner controller 23 for controlling this is provided in the body of the instant water heater. The burner controller 23 also performs hot water temperature control, ignition control, and the like, but since it is not directly related to the present invention, a configuration associated with these processes, such as a temperature sensor and a flow rate sensor, is used. The description and illustration of the ignition device and the like are omitted.

The burner controller 23 includes a CPU, a RAM, and a ROM which form an arithmetic logic operation circuit (not shown).
The microcomputer is provided with a drive circuit, an input / output interface, etc., and receives a detection signal from the CO sensor 21 and, according to the detected CO concentration, the solenoid valves 12, 13
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, which is started in accordance with ignition operation. When this routine is started, first, the signal from 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 clogging of the fins of the heat exchanger 16 or the exhaust stack 20 due to exhaust gas recirculation or combustion products, the display 22 is blinked to give an alarm to the user and a timer is provided. Is activated (S11).

Next, when the CO concentration is the second reference concentration C2 (C2
> C1) or higher (S12), and if the second reference concentration is C2 or higher, the solenoid valves 12 and 13 are closed and the device is stopped (S13). At the same time, the timer is reset and the blinking of the display unit 22 which is displaying the alarm is stopped.

When 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 is up, that is, whether or not a predetermined period T has elapsed since the alarm was issued. (S14), if the time is not up, the process proceeds to step 12.

That is, in this incomplete combustion prevention control process, as shown in FIG. 4, the CO concentration increases and the first reference concentration C1 increases.
When the instrument continues to be used as it is, the CO concentration rises as it is due to exhaust gas recirculation, etc., and the second reference concentration is reached. When the device reaches the temperature limit, the equipment is stopped, and as shown in (a) of the figure, if the second reference concentration C2 is not reached due to the adherence of combustion products, etc., but an alarm is issued for a predetermined period T, Stops the instrument.

As a result, not only can the alarm be used to recognize the timing of removal of combustion products, but even if the user ignores the alarm and continues to use the equipment, if the CO concentration becomes high, the equipment is stopped and the CO concentration becomes low. However, since the appliance is stopped after the lapse of the predetermined period T in consideration of CO outflow to another room due to defective exhaust equipment or the like, the safety is extremely high not only in the appliance installation room but also in the other room.

The embodiment of the present invention has been described above.
The present invention is in no way limited to these examples,
Needless to say, the present invention can be implemented in various modes without departing from the scope 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 of time elapses with an alarm being issued, so that it can be used only in a room where combustion equipment is installed. In addition, CO outflow to another room due to defective exhaust equipment is dealt with, and an excellent effect of having extremely high safety performance is exhibited.

[Brief description of 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 showing 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 exhaust equipment.

[Explanation of symbols]

10 ... Case, 11 ... Gas burner, 12 ... Original solenoid valve, 1
3 ... Proportional solenoid valve, 14 ... Gas supply path, 20 ... Exhaust pipe, 2
1 ... CO sensor, 22 ... Indicator, 23 ... Burner controller

Claims (1)

Claim: What is claimed is: 1. A CO sensor provided in an exhaust passage of a gas burner for detecting a CO concentration in exhaust gas, an opening / closing means for opening / closing a gas supply passage to the gas burner, and the above-mentioned detected. An alarm means for comparing the CO concentration with a preset first reference concentration, and issuing an alarm when the CO concentration exceeds the first reference concentration, and the detected CO concentration and higher than the first reference concentration. The second reference concentration is compared, and when the CO concentration exceeds the second reference concentration, the first stop means for stopping the gas supply to the gas burner by the opening / closing means, and the alarm by the alarm means. Incomplete combustion prevention device, comprising: second stop means for stopping the gas supply to the gas burner by the opening / closing means when the combustion by the gas burner continues for a predetermined period in this state.