JP3895891B2 - Gas-fired hot air heater with air purifier - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a gas-fired hot air heating device with an air cleaner.
[0002]
[Prior art]
Conventionally, gas leak alarms for fuel gas such as city gas and LP gas are commercially available and widely used, but in most cases, the installation location is the kitchen, and there are few cases where it is installed in a residence or bedroom .
[0003]
However, gas-fired hot air heaters are often used mainly in living rooms and bedrooms. Even if a gas leak occurs in the living room or bedroom, it is far away from the kitchen where the gas leak alarm is installed. If there is, there was a fear that the gas leak alarm was delayed or could not be alarmed.
[0004]
On the other hand, gas-fired hot air heaters are provided with an air cleaner that removes cigarette smoke, dust, dust, etc. in the room. The filter cannot adsorb the fuel gas, and has no function of detecting the fuel gas.
[0005]
[Problems to be solved by the invention]
The present invention has been made in view of the above points. The object of the present invention is to use a semiconductor gas sensor that detects air pollution by a gas component contained in indoor cigarette smoke as a fuel gas leak detection sensor. Another object of the present invention is to provide a gas-fired hot air heating device with an air purifier that can avoid the occurrence of a disaster due to gas leakage and is inexpensive.
[0006]
[Means for Solving the Problems]
In order to achieve the above object, according to the first aspect of the present invention, in a gas-fired hot air heating apparatus with an air purifier, which is provided with an air purifier and hot air heating means, is provided in the vicinity of the air intake of the air purifier. Further, a semiconductor type gas sensor whose resistance value changes with respect to a hydrogen component and fuel gas contained in tobacco smoke in an atmosphere in contact with the gas sensitive body surface, and a semiconductor type gas sensor based on the hydrogen component contained in tobacco smoke. Air pollution caused by cigarette smoke and leakage of fuel gas are discriminated and detected based on threshold values set based on changes in resistance values and changes in resistance values of semiconductor gas sensors due to fuel gas. And a control means for controlling the operation of the machine and stopping the combustion operation of the hot air heating means when a fuel gas leak is detected.
[0007]
In the invention of claim 2. Cigarette smoke in an atmosphere in contact with the surface of the gas sensitive body provided in the vicinity of the air intake port of the air purifier in the gas combustion type hot air heating apparatus equipped with an air purifier and a hot air heating means. The semiconductor gas sensor whose resistance value changes with respect to the hydrogen component and fuel gas contained in the gas, the change in resistance value change of the semiconductor gas sensor due to the hydrogen component contained in tobacco smoke, and the resistance of the semiconductor gas sensor due to the fuel gas Based on the threshold value set based on the change in value, air pollution caused by cigarette smoke and fuel gas leakage are discriminated and detected, and when the air pollution is detected, the operation of the air purifier is controlled. And a control means for controlling the alarm operation.
[0008]
According to a third aspect of the present invention, in the second aspect of the present invention, the control means controls the alarm operation of the alarm means and stops the combustion operation of the hot air heater when the fuel gas leakage is detected.
[0009]
Thus, according to the first aspect of the invention, when the fuel gas is detected in addition to the pollutant gas contained in the cigarette smoke in the air by the semiconductor type gas sensor, the combustion operation of the hot air heater is stopped by the control means. It is possible to prevent a gas leak disaster by automatically preventing the occurrence of a fire in the event of a gas leak.
[0010]
According to the second aspect of the present invention, when the fuel gas is detected in addition to the pollutant gas contained in the cigarette smoke in the air by the semiconductor type gas, the control means can operate the alarm means to issue an alarm. When the gas leaks, the fire can be prevented and the gas leak disaster can be avoided.
[0011]
The invention of claim 3 has the effect of the inventions of claims 1 and 2.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
The present invention will be described below with reference to an embodiment.
[0013]
FIG. 1 shows a schematic configuration of a hot air heating apparatus with an air purifier according to an embodiment of the present invention. The hot air heating apparatus with an air purifier of this embodiment has an air purifier 2 at the upper part of the apparatus main body 1. The hot air heater 3 which is a hot air heating means for comprising a hot air heater is built in the lower part.
[0014]
Here, the hot air heater 3 of the present embodiment heats air by burning combustible gas such as city gas or propane gas, and includes a gas combustion chamber 5 provided with a gas burner (not shown), a motor It is comprised with the warm air fan 4 which consists of an axial-flow fan driven by (not shown).
[0015]
An air suction port 6 is opened at the lower back of the apparatus main body 1 corresponding to the gas combustion chamber 5, and the hot air fan 4 rotates to the outside from the air suction port 6 through the air filter 7 into the gas combustion chamber 5. The air is sucked in more and heated by gas combustion with a gas burner (not shown) in the gas combustion chamber 5, and the heated air is blown forward from the hot air outlet 8 opened at the lower front of the apparatus main body 1. It is like that. In the figure, 9 is a joint with the gas pipe.
[0016]
In the warm air heater 3, the room temperature detected by a temperature sensor (not shown) such as a thermistor becomes a target temperature set by a setting means (not shown) under the control unit 10 shown in FIG. As described above, the combustion amount of the gas burner is controlled by a proportional valve (not shown), and the rotation of the hot air fan 4 is controlled by the amount of heat.
[0017]
On the other hand, the air purifier 2 is taken in from an air purifier fan 12 that is rotationally driven by a fan driving motor 11 disposed inside the apparatus main body 1 and an air intake port 13 that is opened in the upper front portion by the rotation of the fan 12. An air cleaning filter 14 that removes air pollutants such as dust and odor from the air, a sensor that is disposed in the air intake port 13, and that detects atmospheric contamination by a hydrogen gas component contained in cigarette smoke and a combustible gas A semiconductor gas sensor 15 that also serves as a sensor for detecting combustion gas, and detects contamination of the air and gas leaks by a change in the detection output of the semiconductor gas sensor 15 to detect the contamination detection signal X and the gas leak in the control unit 10. The sensor signal processing unit 16 (see FIG. 2) that outputs the signal Y is configured, and the rotation of the fan driving motor 11 is contaminated by the sensor signal processing unit 16. And it is controlled by a control unit 10 for inputting the detection signal X.
[0018]
The air purified by the air cleaning filter 14 is blown into the room through an air outlet 17 opened in the ceiling surface of the apparatus main body 1.
[0019]
The air cleaner 2 itself can be operated independently of the hot air heater 3 so that it can be used regardless of the season.
[0020]
As shown in FIG. 3, the semiconductor gas sensor 15 used in the present embodiment accommodates a metal case 19 in which a gas sensitive body 15a shown in FIG. 4 is housed at the bottom of a cylindrical resin housing 18, and a cylindrical metal case. 19 and a stainless steel net 20 attached to the upper opening of the housing 18 are filled with a filter 21 made of activated carbon, and the electrode pins 22 a to 22 c protruding from the bottom of the metal case 19 protrude outside from the bottom of the housing 18. 3 terminal structure.
[0021]
The gas sensitive body 15a accommodated in the metal case 19 is made of, for example, a metal oxide formed in an elliptical shape having a diameter in the longitudinal direction of approximately 0.5 mm and a diameter in the short direction of approximately 0.3 mm. As shown in FIG. 2, the heater coil 15b made of a noble metal wire and the wire electrode 15c made of a noble metal wire are embedded therein, and terminals 22a, 22c projecting into the metal case 19 at both ends of the heater coil 15b in the metal case 19. The wire electrode 15 c is held in the metal case 19 by being electrically and mechanically connected to the upper end of the wire electrode 15 c and electrically and mechanically connected to the upper end of the terminal 22 b protruding into the metal case 19.
[0022]
The gas sensitive body 15a is mixed with SnO ₂ containing Pd or an alternative metal, or an equivalent amount of, for example, 1000 mesh α-alumina as an aggregate in SnO ₂ and further added with terpione to form a paste. What was obtained by applying a paste-like material to the heater coil 15b and the wire electrode 15c, firing in air at a predetermined temperature for a predetermined time, adding alumina sol after baking and further baking at a predetermined temperature for a predetermined time It is.
[0023]
FIG. 5 shows an equivalent circuit of the semiconductor gas sensor 15, _RH is the resistance value of the heater coil 15 b, Rs is the resistance of the gas sensitive body 15 a between the wire electrode 15 c and one end of the heater coil 15 b (terminal 22 a side). Indicates the resistance value.
[0024]
Thus, in the semiconductor gas sensor 15 having such a structure, the surface of the gas sensitive body 15a heated to about 400 ° C. by the heater coil 15ba is in contact with a hydrogen gas component contained in tobacco smoke or a combustible gas as a combustion gas. Then, the resistance value Rs has a characteristic of changing in a decreasing direction.
[0025]
The sensor signal processing unit 16 shown in FIG. 2 performs pulse width control on the voltage applied to the constant voltage circuit 23 that obtains a predetermined DC voltage Vc (for example, 5 V) from the AC power supply AC and the heater coil 15 b of the semiconductor gas sensor 15. The transistor Q inserted in series between the heater coil 15b between the terminals 20a and 20c of the semiconductor gas sensor 15 and the output terminal of the constant voltage circuit 23, the terminal 20b of the semiconductor gas sensor 15 and the positive output terminal of the constant voltage circuit 23 And a load resistor R for dividing the output voltage of the constant voltage circuit 23 by the gas sensitive body 15a, and a drive pulse for pulse width control from the drive circuit 24 built in the base of the transistor Q via the resistor R1. Is output to control the pulse width of the switching of the transistor Q, and the voltage across the gas sensitive body 15a is taken in via the A / D conversion circuit 26. Then, the contamination of the atmosphere and the gas leakage are detected by detecting the change in the resistance value Rs of the gas sensitive body 15a, and the contamination detection signal X and the gas leakage detection are detected by the control unit 10 via the output circuit 25 based on the detection result. A signal processing circuit 27 that outputs the signal Y and an arithmetic processing unit 29 including a memory 28 are included. The arithmetic processing unit 29 is actually composed of a microcomputer.
[0026]
The voltage applied to the heater coil 15b is controlled to be approximately 0.9 V on average by pulse width control by switching of the transistor Q, so that the heating temperature by the heater coil 15b is approximately 400 ° C.
[0027]
Next, detection of atmospheric contamination and detection of gas leakage in the present embodiment will be specifically described.
[0028]
First, the resistance value of the gas sensitive body 15a of the semiconductor gas sensor 15 under clean air is set as a reference resistance value Rstd, and this reference resistance value Rstd is registered in advance in the memory 28 in the arithmetic processing unit 29, and the signal processing circuit 27 Detects the resistance value Rs of the gas sensing element 15a from the voltage across the gas sensing element 15a taken in through the A / D conversion circuit 26, and the ratio of the resistance value Rs to the reference resistance value Rstd (hereinafter referred to as resistance change rate (Rs / Rstd). )) And the resistance change rate (Rs / Rstd) obtained by this calculation exceeds the threshold for contamination detection or gas leak detection set in the memory 26 in the arithmetic processing unit 29 in advance. It is determined that there is contamination or gas leakage.
[0029]
The resistance value Rs of the gas sensitive body 15a of the semiconductor type gas sensor 15 to be used changes under a normal warm air heater 2 in the heating operation, and in the clean air, changes substantially in the vicinity of the reference resistance value Rstd as shown in FIG. The resistance change rate (Rs / Rstd) shows a characteristic of approximately 1, but when a hydrogen gas component or fuel gas comes into contact, the resistance value Rs changes, and the resistance change rate (Rs / Rstd) is 1. Smaller.
[0030]
FIG. 7 shows a state in which the warm air heater 2 with the air purifier of the present embodiment is installed near the wall in a room having a predetermined volume as an experimental space (floor area is 8 tatami mats) and the warm air heater 2 is in an operating state. FIG. 7 shows the measurement result of the resistance change rate (Rs / Rstd) of the gas sensitive body 15a of the semiconductor gas sensor 15 when a single cigarette smoke is generated in the center of the room. In the measurement result of FIG. The resistance change rate (Rs / Rstd) starts to change, and after about 30 seconds, the resistance change rate (Rs / Rstd) changes at about 0.85. Similarly, when smoking 10 cigarettes at a time, the rate of change in resistance (Rs / Rstd) was not shown in the figure, but a result of changing at about 0.55 was obtained.
[0031]
On the other hand, the resistance change rate (Rs / Rstd) of the gas sensitive body 15a of the semiconductor gas sensor 15 when the gas leakage state was reproduced in the same room with the combustion of the hot air heater 2 stopped was measured. Immediately after that, the resistance value Rs of the gas sensitive gas 15a starts to decrease, and after about 13 minutes, the resistance change rate (Rs / Rstd) becomes very small as 0.35 as shown in FIG. Rs / Rstd) was significantly different. The gas concentration at this time was 1850 ppm. On the other hand, since the filter 14 of the air cleaner 3 does not have the ability to adsorb fuel gas, even if the air cleaner 3 is operated, the resistance change rate (Rs / Rstd) shows the above value.
[0032]
Here, in the present embodiment, based on the above measurement result, the value of 0.85 is set as the threshold value for starting the operation of the air cleaner 3, and 0.95 is set as the threshold value when stopping after the start of the operation. The gas leak detection threshold value is set and registered in the memory 28 as 0.3.
[0033]
As described above, the signal processing circuit 27 calculates the registered threshold value and the resistance change rate (Rs / Rstd) obtained based on the voltage across the gas sensitive body 15 a of the semiconductor gas sensor 15 taken in through the A / D conversion circuit 26. By comparing, air pollution detection and gas leak detection can be performed.
[0034]
Thus, in the hot air heating apparatus with an air cleaner of the present embodiment, the resistance change rate (Rs / Rstd) of the gas sensitive body 15a of the semiconductor gas sensor 15 in the air intake 13 of the air cleaner 2 is 0.85. If the value is less than, the signal processing circuit 27 of the arithmetic processing unit 29 determines that there is air contamination and outputs the contamination detection signal X to the control unit 10 through the output circuit 25.
[0035]
The control unit 10 having received the contamination detection signal X starts the operation of the fan drive motor 11 to rotate the cleaner fan 12 to operate the air cleaner 2. This operation is continued until the rate of resistance change (Rs / Rstd) of the gas sensitive body 15a of the semiconductor gas sensor 15 exceeds 0.95 and the contamination detection signal X is no longer input from the signal processing circuit 27.
[0036]
On the other hand, during the operation of the hot air heater 3, fuel gas leaks due to extinction or the like, and the rate of change in resistance (Rs / R) of the gas sensitive body 15 a of the semiconductor gas sensor 15 in the air intake 13 of the air cleaner 2. When Rstd) falls below the threshold value of 0.3, the signal processing circuit 27 outputs the gas leak detection signal Y to the control unit 10 through the output circuit 25.
[0037]
When the gas leak detection signal Y is input, the controller 10 closes the solenoid valve (not shown) to supply the fuel gas to the hot air heater 3 to stop the gas outflow from the gas burner in the combustion chamber. The combustion operation is forcibly stopped, and an alarm buzzer 30 as alarm means is sounded to notify the gas leak.
[0038]
FIG. 9 shows the measurement result of the resistance change rate (Rs / Rstd) of the gas sensitive body 15a of the semiconductor gas 15 in the operating state of the hot air heater 3 and the air cleaner 2 under clean air. The measurement result of the resistance change rate (Rs / Rstd) of the gas sensitive body 15a of the semiconductor type gas 15 when the hot air heater 3 and the air purifier 2 are operated in an atmosphere in which a cigarette is smoked is shown. FIG. 11 shows the measurement result of the resistance change rate (Rs / Rstd) of the gas sensitive body 15a of the semiconductor type gas 15 when the hot air heater 3 and the air purifier 2 are operated in a gas leakage state. It can be seen from 10 that the air purifier 2 is operated and the air is being purified. Further, FIG. 11 shows that the filter 14 of the air purifier 2 does not adsorb the fuel gas.
[0039]
In this way, in the present embodiment, the semiconductor gas sensor 15 that detects air contamination of the air cleaner 3 also serves as a sensor that detects fuel gas leakage. Based on the detection of the semiconductor gas sensor 15 in the event of a gas leak, Disasters due to gas leak accidents can be avoided.
[0040]
In the above-described embodiment, control is performed so that an alarm is sounded and the combustion operation is stopped when a gas leak is detected, but either one may be used.
[0041]
Further, the threshold value for detecting the contamination or gas leakage may be updated without being fixed.
[0042]
Further, although the semiconductor gas sensor 15 is provided in the air intake port 13, it may be inside or outside as long as it is in the vicinity of the air intake port 13.
[0043]
【The invention's effect】
The invention according to claim 1 is a gas combustion type hot air heating apparatus equipped with an air cleaner and a hot air heating means, and is in contact with the surface of the gas sensitive body provided in the vicinity of the air intake of the air cleaner. A semiconductor gas sensor whose resistance value changes with respect to a hydrogen component and fuel gas contained in tobacco smoke in a flowing atmosphere, a change in resistance value of the semiconductor gas sensor due to a hydrogen component contained in tobacco smoke, and a fuel A semiconductor gas sensor that detects air pollution and fuel gas leakage due to cigarette smoke based on a threshold set based on changes in resistance of the semiconductor gas sensor due to gas, and changes its resistance value due to pollutant gas and fuel gas. In addition, air pollution and fuel gas leakage are discriminated and detected by changing the resistance value of the semiconductor gas sensor. When air pollution is detected, the operation of the air purifier is controlled, and the fuel gas leakage is detected. Since the time of detection and control means for stopping the combustion operation of the warm-air heating means, the semiconductor gas sensor, there is the fuel gas can be detected in addition to cigarette smoke contained in the air, fuel gas leak is detected Then, it is possible to stop the combustion operation of the hot air heater by the control means, and as a result, it is possible to automatically prevent the occurrence of a fire in the event of a gas leak and to avoid a gas leak disaster. In addition, since the semiconductor type gas sensor serves as both an air pollution detection sensor and a gas leak detection sensor, only one sensor is required, the sensor signal processing can be simplified, and the cost of the resulting device can be reduced. is there.
[0044]
In the invention of claim 2, in the gas-fired hot air heating apparatus equipped with an air cleaner and a hot air heating means, and in contact with the surface of the gas sensitive body provided near the air intake of the air cleaner. A semiconductor gas sensor whose resistance value changes with respect to a hydrogen component and fuel gas contained in tobacco smoke in a flowing atmosphere, a change in resistance value of the semiconductor gas sensor due to a hydrogen component contained in tobacco smoke, and a fuel Based on the threshold value set based on the change in resistance value of the semiconductor gas sensor due to gas, air pollution caused by cigarette smoke and fuel gas leakage are discriminated, and when air pollution is detected, the operation of the air purifier is controlled to since at the time of gas leakage detection and control means for controlling the alarm operation of the alarm means, the semiconductor gas sensor, fuel gas can be detected in addition to cigarette smoke contained in the air Therefore, when a fuel gas leak is detected, the control means can operate the alarm means to notify the user of the gas leak. As a result, it is possible to prevent the occurrence of a fire in the event of a gas leak, There is an effect that a leakage disaster can be avoided, and the semiconductor type gas sensor serves as both an air pollution detection sensor and a gas leakage detection sensor, so that only one sensor is required, and the processing of the sensor signal can be simplified. There is an effect that the cost of the result apparatus can be reduced.
[0045]
In the invention of claim 3, in the invention of claim 2, the control means controls the alarm operation of the alarm means and detects the combustion operation of the hot air heater when the fuel gas leakage is detected. In addition to the effect, the effect of the invention of claim 1 is obtained.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram of an embodiment of the present invention.
FIG. 2 is a circuit configuration diagram used in the above.
FIG. 3 is a partially broken perspective view of the semiconductor gas sensor used in the above.
FIG. 4 is a diagram illustrating the configuration of a gas sensitive body of the semiconductor gas sensor used in the above.
FIG. 5 is an equivalent circuit diagram of the semiconductor gas sensor used in the above.
FIG. 6 is a graph showing a change in resistance change rate of a gas sensitive body of a semiconductor gas sensor under clean air.
FIG. 7 is a graph showing a change in resistance change rate of a gas sensitive body of a semiconductor gas sensor when a hot air heater is operated under polluted air.
FIG. 8 is a graph showing a transition of another example of the resistance change rate of the gas sensitive body of the semiconductor gas sensor when the hot air heater is operated under gas leakage.
FIG. 9 is a graph showing the transition of the resistance change rate of the gas sensitive body of the semiconductor gas sensor when the hot air heater and the air cleaner are in an operating state under clean air.
FIG. 10 is a graph showing a change in resistance change rate of the gas sensitive body of the semiconductor gas sensor when the hot air heater is operated in a state where the hot air heater and the air purifier are operating under the contaminated air. is there.
FIG. 11 is a graph showing the transition of the resistance change rate of the gas sensitive body of the semiconductor gas sensor when the hot air heater and the air cleaner are in an operating state under gas leakage.
[Explanation of symbols]
3 Hot Air Heating Machine 10 Control Unit 15 Semiconductor Gas Sensor 15a Gas Sensitive Body 25 Output Circuit 27 Signal Processing Circuit 30 Alarm Buzzer X Contamination Detection Signal Y Gas Leak Detection Signal

Claims (3)

In a gas-fired hot air heating apparatus equipped with an air purifier and an air purifier and having an air purifier, cigarette smoke in an atmosphere in contact with the surface of the gas sensitive body provided near the air intake of the air purifier The semiconductor gas sensor whose resistance value changes with respect to the hydrogen component and fuel gas contained in the gas, the change in resistance value of the semiconductor gas sensor due to the hydrogen component contained in tobacco smoke, and the resistance of the semiconductor gas sensor due to the fuel gas Detects air pollution and fuel gas leakage due to cigarette smoke based on thresholds set based on changes in value , controls air purifier operation when air pollution is detected, and warm air heating when fuel gas leakage is detected And a control means for stopping the combustion operation of the means. A gas combustion type hot air heating apparatus with an air purifier. In a gas-fired hot air heating apparatus equipped with an air purifier and an air purifier and having an air purifier, cigarette smoke in an atmosphere in contact with the surface of the gas sensitive body provided near the air intake of the air purifier The semiconductor gas sensor whose resistance value changes with respect to the hydrogen component and fuel gas contained in the gas, the change in resistance value of the semiconductor gas sensor due to the hydrogen component contained in tobacco smoke, and the resistance of the semiconductor gas sensor due to the fuel gas Based on the threshold value set based on the change in value, air pollution caused by cigarette smoke and fuel gas leakage are discriminated and detected, and the air purifier operation is controlled when air pollution is detected. A gas-fired hot-air heating device with an air cleaner, characterized by comprising control means for controlling an alarm operation. 3. The gas-fired hot air heating apparatus with an air cleaner according to claim 2, wherein the control means controls an alarm operation of the alarm means when detecting fuel gas leakage and stops combustion of the hot air heater.

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