JP2538648Y2 - Carbon monoxide concentration determination 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 carbon monoxide concentration judging device for performing a predetermined process according to the concentration of carbon monoxide in a combustion gas.

[0002]

2. Description of the Related Art In a gas burner such as a gas stove using liquefied petroleum gas as a fuel, incomplete combustion generates carbon monoxide (CO) which has an adverse effect on the human body. This CO is detected by a sensor. There is a CO alarm that issues an alarm by a lamp or a buzzer and notifies the user. The sensor for detecting CO is used while being kept at a high temperature by a built-in heater.

If such a CO alarm is connected to, for example, a gas meter (a so-called microcomputer meter) containing a microcomputer, the use of gas is stopped by closing a shut-off valve built in the gas meter when CO is detected. Can be controlled. FIG. 12 shows the CO concentration in the combustion gas, the heater voltage applied to the heater for 60 seconds so that the CO sensor detects the concentration every 2 minutes and 30 seconds, the CO sensor output, and the green color in such a conventional CO alarm. LED
FIG. 5 is a timing chart showing an energization display lamp made of, a preliminary alarm lamp made of a yellow LED, an alarm lamp made of a red LED, an alarm buzzer that sounds simultaneously with the turning on of the alarm lamp, and an external output to the gas meter.

According to this, the output of the CO sensor is CO
There are two stages, a first stage set value and a second stage set value, according to the concentration. Times t ₁ and t when the first stage CO concentration is detected
₂ turns on the preliminary alarm lamp. When the lighting of the preliminary alarm lamp is continued for 5 minutes or more it has been detected CO concentration between, or two or more stage from (time t ₂ ~t ₃₎ until the CO concentration of less than 1 stage (time t ₄₎ From time (time t5) until the CO concentration becomes lower than the first stage (time t6),
The alarm buzzer sounds at the same time as the alarm lamp lights.
The external output to the gas meter, that is, the output of the shutoff valve closing signal, is performed simultaneously with the alarm lamp and the alarm buzzer.

[0005]

However, in such a conventional CO alarm device system, although the output of the CO sensor is set in two stages and the alarm output is also in two stages, the gas meter as an external device is used. When the first-stage density detection continues for 5 minutes or more,
Alternatively, the gas concentration is detected when the concentration of the second stage is detected. For this reason, the gas meter cannot determine the CO concentration level. Therefore, the time from the detection of CO to the closing of the shut-off valve according to the CO concentration is considered. There is a problem that detailed control is not possible.

[0006] Therefore, an object of the present invention is to make it possible to determine the concentration of carbon monoxide in an external device that receives an external output signal from the alarm output means, and to enable more fine-grained control in the external device.

[0007]

According to the present invention, as shown in FIG. 1, an alarm is output in accordance with the concentration of carbon monoxide in a combustion gas and a signal is output to an external device 9 as shown in FIG. Alarm output means 7; limit time setting means 11a for receiving an output signal of the alarm output means 7 to the external device 9 and setting a time limit based on the concentration of carbon monoxide in accordance with the output signal; And a control signal output means 11b for outputting a control signal when the set time reaches a set time limit.

[0008]

According to the carbon monoxide concentration judging device having such a configuration, the alarm output means 7 outputs an alarm according to the carbon monoxide concentration and outputs a signal to the external device 9. Based on the signal received by the external device 9, the time limit setting means 11a sets a time limit in accordance with the concentration of carbon monoxide, and when the set time limit is reached, the control signal output means 11b outputs a control signal. .

[0009]

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 2 is a block diagram of an apparatus for determining the concentration of carbon monoxide according to an embodiment of the present invention. The CO sensor detects the concentration of carbon monoxide (CO) contained in the combustion gas discharged from the combustor. The detection signal 1 is input to a control circuit 3 including a microcomputer or the like. The CO sensor 1 is used while being kept at a high temperature by a built-in heater. The control circuit 3 detects the CO detected by the CO sensor 1
A signal is output to an alarm lamp and an alarm buzzer 5 according to the density level. The CO sensor 1, the control circuit 3, the alarm lamp and the alarm buzzer 5 allow C
The O alarm 7 is constituted.

A gas meter 9 as an external device is connected to the control circuit 3 of the CO alarm 7. This gas meter 9 is a control circuit 1 composed of a microcomputer.
1 is a so-called microcomputer meter having a shut-off valve 13 that is closed by a command from the control circuit 11 when an abnormality occurs in the gas flow rate. Therefore, the control circuit 11
Includes a control signal output unit 11a for the shut-off valve 13.

As shown in FIG. 3, the CO concentration level detected by the CO sensor 1 is level 1 when the concentration is 50 ppm or more and less than 200 ppm, and level 2 when the concentration is 200 ppm or more and less than 500 ppm.
There are three levels with 500 ppm or more as level 3, and the output signal to the gas meter 9 is determined according to the three levels of concentration. Since the gas meter 9 receives an external output signal corresponding to the concentration level from the alarm device 7, it is possible to estimate the CO concentration from the gas meter 7 side.

FIG. 4 shows the CO concentration and C in the alarm 7.
4 is a timing chart showing a heater voltage, a CO sensor output, and an external output to the gas meter 9 applied to a built-in heater so that the O sensor 1 performs concentration detection every 2 minutes and 30 seconds. Here, as the external output, in addition to the pattern 1 shown in FIG. 3, three types of signals corresponding to the density levels may be output by a combination of the output 1 and the output 2 like the pattern 2. Although the operation timing of the alarm lamp and alarm buzzer is not described here,
A configuration similar to the conventional example shown in FIG. 10 may be used.

The closing timing of the shut-off valve 13 by the control circuit 11 in the gas meter 7 is different depending on the external output signal from the alarm 7, that is, the CO concentration, and the time from the detection of the concentration to the closing of the shut-off valve 13 ( Time limit) H is
The risk of CO harming the human body D is the CO concentration (ppm)
Since it is the product of P and time H, it can be calculated from D = P × H. Therefore, the control circuit 11 controls the time limit setting means 1
1a. As shown in FIG. 5, the time limit H is less than the concentration level 1 at which the maximum concentration is 50 ppm.
Since CO has almost no effect on the human body, "None"
In the concentration level 1 where the maximum concentration is 200 ppm, the time is shortened to "1 hour", and in the concentration level 2 where the maximum concentration is 500 ppm, the time is shortened to "0.4 hour". At the concentration level 3 of 500 ppm or more, the shut-off valve 13 is immediately shut off after receiving the external output signal.

Next, the operation of the alarm system configured as described above will be described with reference to FIG.
A description will be given based on the flowchart of FIG. Based on the CO concentration (concentration levels 1 to 3) detected by the CO sensor 1, the alarm 7
The control circuit 3 determines whether the CO concentration is one of the concentration levels 1 to 3 and outputs the same to the control circuit 11 on the gas meter 9 side in accordance with the determined concentration level. Measurement is performed (step 101). After the concentration measurement, the control circuit 11 determines whether or not there has been a change from the previous concentration measurement (step 103). If there has been a change, the limit time H is set in consideration of the elapsed time at the previous concentration. (Step 105). Step 10
If there is no change in concentration in step 3, it is determined whether or not the time limit H has been reached (step 107). (Step 109).

FIGS. 7 to 9 show another embodiment of the present invention. In this embodiment, as shown in FIG. 7A, the configuration of the alarm device 7 is such that the time t of the external output increases as the concentration detected by the CO sensor 1 every 2 minutes and 30 seconds increases. ). This makes it possible to detect the CO concentration on the gas meter 9 side. FIG. 8 shows the relationship between the CO concentration and the time limit H derived from the CO concentration P × the time limit H = 200 with the risk D set to 200. According to this, the time limit H is increased as the CO concentration increases. It is getting shorter. Note that the block configuration of the carbon monoxide concentration determination device in this embodiment is the same as that in FIG.

The operation of the alarm system in this embodiment will be described with reference to the flowchart of FIG. CO detected by CO sensor 1
Based on the concentration, the control circuit 3 of the alarm 7 determines the time t of the external output according to the CO concentration based on FIG. 7B, and the control circuit 11 of the gas meter 9 that receives the external output signal for the determined time t is: The CO concentration is determined based on FIG. 7B (step 201). Next, it is determined whether or not the CO concentration exceeds 50 ppm (step 203). If so, it is determined whether or not the monitoring timer built in the control circuit 11 has been started (step 20).
5).

If the monitoring timer has not started, the time limit H is set based on the time limit H = 200 ÷ CO concentration P (step 207), and the monitoring timer is started (step 209). If the CO concentration is 50 ppm or less in step 203, the risk of CO being given to the human body is extremely low. Therefore, after the monitoring timer start determination process (step 211), the monitoring timer is stopped if started (step 211). 213).

If the monitoring timer has been started in step 205, it is determined whether the current measured density is within 10% of the previous measured density (step 215).
If the current measured concentration is as low as 10% or less, the measurement time of the monitoring timer is compared with the time limit H (step 217). If so, the time limit H is changed (step 219), and the measured time is compared with the time limit H in step 217. Here, when the time measured by the monitoring timer exceeds the time limit H, the shutoff valve 13 is shut off to stop gas supply, and a notification process is performed to the gas management company (step 221).

As described above, the gas meter 9 receiving the external output signal from the alarm 7 determines the CO concentration based on the external output signal, and calculates the time limit H until the shut-off valve 13 is closed according to the CO concentration. However, since the supply of gas can be stopped by closing the shutoff valve 13 when the time limit H has been reached, finer control can be performed according to the CO concentration, and the safety of the human body can be reduced from the CO contained in the combustion gas. It can be protected reliably.

FIG. 10 shows the configuration of the alarm 7 based on the ratio of the on-time A and the off-time B of the external output to the gas meter 9 to the CO concentration detected by the CO sensor 1 every 2 minutes and 30 seconds. The duty ratio is changed. In this case, as the CO concentration increases, the ratio of the output (ON) time A is increased, but this output time A is limited to the next concentration measurement (2 minutes 30 seconds). FIG.
5 is a timing chart based on an output signal format as described above. According to this, when the ratio of the ON time A is CO
It can be seen that the density increases as the concentration increases.

Although a gas meter is used as an external device in each of the above embodiments, another device may be used instead of the gas meter.

[0023]

As described above, according to the present invention, an external device that receives an external output signal from an alarm output unit that outputs an alarm in accordance with the concentration of carbon monoxide requires a carbon monoxide based on the external output signal. Set a time limit according to the concentration,
Since the control signal is output when the time limit is reached, the external device can output the control signal more finely according to the carbon monoxide concentration.

[Brief description of the drawings]

FIG. 1 is a diagram corresponding to claims of the present invention.

FIG. 2 is a control block diagram showing an embodiment of the present invention.

FIG. 3 is an explanatory diagram showing an external output signal corresponding to a concentration level of carbon monoxide in the alarm device of FIG. 2;

FIG. 4 is a timing chart in the alarm device of FIG. 2;

FIG. 5 is an explanatory diagram showing a relationship between a density level and a time limit in the embodiment of FIG. 2;

FIG. 6 is a flowchart showing a control operation in the embodiment of FIG.

FIG. 7 is an explanatory diagram showing a relationship between the concentration of carbon monoxide and an external output in an alarm device according to another embodiment of the present invention.

8 is an explanatory diagram showing the relationship between the concentration of carbon monoxide and the time limit in the embodiment of FIG.

FIG. 9 is a flowchart showing a control operation in the embodiment of FIG. 7;

FIG. 10 is an explanatory diagram showing another example of the external output signal with respect to the carbon monoxide concentration of the alarm device.

FIG. 11 is a timing chart in the alarm device using the external output signal format of FIG. 10;

FIG. 12 is a timing chart of a conventional alarm device.

[Explanation of symbols]

Reference Signs List 1 CO sensor 7 Alarm (alarm output means) 9 Gas meter (external device) 11 Control circuit (limit time setting means, control signal output means)

Claims (1)

(57) [Scope of request for utility model registration] An alarm output means for outputting an alarm according to the concentration of carbon monoxide in a combustion gas and outputting a signal to an external device, and receiving an output signal of the alarm output means to the external device in response to the output signal A time limit setting means for setting a time limit based on the concentration of carbon monoxide, and control signal output means for outputting a control signal when the time limit set by the time limit setting means is reached. Carbon oxide concentration determination device.