JPH0835650A - Open type gas burning instrument equipped with incomplete combustion-preventing device - Google Patents

Abstract

PURPOSE:To provide an open type gas burning instrument, in which an incom plete combustion-preventing device responds properly in accordance with environ ment in use size of a room, ventilating property and the like). CONSTITUTION:When incomplete combustion is detected by the composite electromotive force of thermocouples 58, 60, combustion is stopped, however, when the continuous operation time is long, it is decided that the environment in use is contaminated and the composite output operation level of the thermocouples is increased to stop the combustion whereby the combustion is stopped quickly. On the other hand, when the composite electromotive force of the thermocouples has become lower, the time of continuous operation is shortened whereby the combustion is stopped quickly. In a reverse case, excessive quick response of stopping combustion is prevented at this time by a reverse control.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a supply / discharge type open type gas combustion equipment such as a main stop type gas water heater which takes in combustion air from the room and discharges the combustion gas as it is from the gas combustion equipment into the room. , To be more precise, such an open type with an incomplete combustion prevention device that shuts off the gas passage before incomplete combustion occurs due to poor ventilation in the room or clogging of fins of the heat exchanger. The present invention relates to gas combustion equipment.

[0002]

2. Description of the Related Art Conventionally, as an open type gas combustion apparatus of this kind, for example, a main stop type gas water heater, when the ventilation in the room is insufficient or the heat exchanger in the apparatus is dirty, the fins are not visible. It becomes difficult for the air required for combustion to be taken into the device when it becomes clogged, but in such cases, incomplete combustion may lead to an accident. This is becoming a big problem, especially in view of the recently highly airtight housing structure. Therefore, in order to solve these problems and to use them more safely, we have installed an incomplete combustion prevention device on these open-type gas combustion equipment and have a mechanism to stop the gas before it becomes dangerous and keep it safe. There is.

Such an incomplete combustion preventing device is, for example, as shown in FIG. 17, a plus and minus of the thermocouple (1) and the thermocouple (2) facing the combustion chamber window below the heat exchanger. Connect the magnets so that their polarities are in the opposite direction, and subtract the electromotive force (V ₂ ) generated by the thermocouple (2) from the electromotive force (V ₁ ) generated by the thermocouple (1) in the magnet safety valve. Is the force to hold the magnet safety valve. When the oxygen concentration in the room decreases, the flame of the burner lifts, the electromotive force of the thermocouple (1) decreases, and the combined electromotive force of V ₁ -V ₂ decreases, making it impossible to hold the magnet safety valve. The gas supply is cut off. When the heat exchanger is clogged due to long-term use, the electromotive force of the thermocouple (2) in the inner shell becomes high due to the heat of the combustion exhaust gas, and the combined electromotive force of V ₁ -V ₂ decreases as described above. Therefore, the magnet safety valve is designed to close. This is to stop the combustion when the oxygen (O ₂ ) concentration in the room reaches a certain value or a certain combustion state is reached.

18 to 20 more specifically show the structure of the incomplete combustion preventing device. Explaining the control block diagram of FIG. 18, the combined electromotive force values of the thermocouples 1 and 2 are detected by the thermoelectromotive force detection circuit 3, and when the incomplete combustion occurs, the operation level (thermocouple 1 The combined electromotive force value of 2) is preset by the detection sensor operation level setting circuit 4. Then, the combined electromotive force values of the two are compared by the combustion continuity determination circuit 5, and when the actual electromotive force value decreases to the operation level for stopping the combustion, the magnet safety valve 7 of the safety valve drive circuit 6 is energized. It is cut off and the gas flow path is closed.

FIG. 19 shows a specific electric circuit diagram for realizing the control block diagram shown in FIG. The reference voltage corresponding to the detection level of incomplete combustion is set to the minus (-) input terminal of the comparator 8 as the combustion continuity determination circuit 5, and the thermocouples 1 and 2 are set to the plus (+) input terminal of the comparator 8. Connecting. When the electromotive force of the thermocouple decreases due to the state of incomplete combustion and falls below a certain detection level for preventing incomplete combustion, the magnet safety valve 7 is de-energized and the gas passage is shut off.

FIG. 20 is a timing chart for explaining the operating state of each member in the electric circuit diagram shown in FIG. As illustrated, the combined electromotive force value (V ₁ -V ₂ ) of the thermocouples 1 and 2 after starting combustion (ignition) increases toward the combustion stable state and reaches the combustion stable state. During that time, the input / output value of the comparator is reversed from Hi to Low at a certain constant thermoelectromotive force value, and the gas solenoid valve is turned on (ON) and opened during that time. After that, when the combustion state begins to deteriorate and the combined electromotive force of the thermocouples 1 and 2 decreases and falls below a certain electromotive force value, the magnet safety valve 7 is turned off (OFF) and is in a closed state. In the initial stage of ignition, the magnet safety valve 7 is not energized, but the gas flow path is opened because it is mechanically opened by the ignition operation.

On the other hand, some gas water heaters of this type automatically stop the combustion after a certain period of use due to the operation of a timer to maintain the safety of using the equipment. Some of them are designed to be safe in use of appliances by using regulations and the above-mentioned incomplete combustion prevention device in combination. In the above example, the detection level of the incomplete combustion detection sensor is constant regardless of the combustion time.

[0008]

However, all of the hitherto generally known ones are intended to ensure safety in using the device under individual conditions. For example, when the usage time is regulated by a timer, the operation is stopped only after a predetermined time has elapsed, and when the combustion state reaches a certain condition, the one with an incomplete combustion prevention device is used. The operation is stopped for the first time.

Further, in the case of using the timer for controlling the usage time and the incomplete combustion preventing device in combination, the operation is stopped only when one of the conditions is satisfied, and in each case, the operation is individually performed. It was decided whether to continue or stop the operation depending on the conditions. However, the open-type gas combustion equipment has a great difference in the air pollution rate depending on the environment in which it is used (or installed) or the ventilation condition of the room. Depending on the continuous operation, the permissible operating time also differs.

Therefore, if it is attempted to control the operation under the individual conditions as described above without considering such a difference in the operating environment, it is considered that the operation is performed in a place with a considerable margin from the actual dangerous state in consideration of safety. I have to

The present invention has been made to solve such a problem, and its purpose is to increase the detection level of an incomplete combustion state as the combustion time increases.
Another object of the present invention is to provide an open type gas combustion device with an incomplete combustion preventive device, which controls safety at a truly necessary position by determining the continuous combustion time according to the output value from the detection sensor to ensure safety. As a result, it is intended to secure safety due to the difference in usage environment and to avoid the problem of malfunctioning in the incomplete combustion state despite the safe operation state.

[0012]

In order to achieve this object, an open type gas combustion apparatus according to the present invention comprises, as a first invention, an incomplete combustion prevention detection sensor means for detecting a combustion state, and this detection sensor. In an open type gas combustion device with an incomplete combustion prevention device, which comprises combustion stopping means for stopping combustion when an abnormality in the combustion state is detected by an output signal from the means, a sensor output for reading the output value of the detection sensor means A value reading means, a combustion time measuring means for measuring an actual continuous combustion time, and an operation level changing means for changing the output operation level of the detection sensor means in which the combustion stopping means operates according to the measured combustion time. Combustion occurs when the sensor output value read by the sensor output value reading means reaches the output operation level changed by the operation level changing means. It is an Abstract by being configured as locked.

In this case, the warning output means for issuing an alarm shortly before the sensor output value read by the sensor output value reading means reaches the output operation level changed by the operation level changing means, and the sensor output value It is preferable to further include combustion stop warning means for issuing an alarm when the sensor output value read by the reading means reaches the output operation level changed by the operation level changing means. If this is done, the user of this gas combustion device will be informed that there is a need for ventilation in the room, the need for maintenance of the device itself, etc., and the usability of this device will be further improved. Is.

A second aspect of the present invention is that incomplete combustion prevention detection sensor means for detecting the combustion state and combustion stop for stopping the combustion when an abnormality in the combustion state is detected by an output signal from the detection sensor means. In an open type gas combustion apparatus with an incomplete combustion prevention device, a sensor output value reading means for reading the output value of the detection sensor means, and an allowable continuous combustion time from the read sensor output value are set. And a combustion time measuring means for measuring the actual continuous combustion time, and the combustion time measured by the combustion time measuring means is the allowable continuous combustion set by the allowable combustion time setting means. The gist is that the combustion is stopped when the time is reached.

In that case, too, the advance warning means for issuing an alarm shortly before the combustion time measured by the combustion time measuring means reaches the allowable continuous combustion time set by the allowable combustion time setting means, and the combustion time. A combustion stop alarm means for issuing an alarm when the combustion time measured by the time measuring means reaches the allowable continuous combustion time set by the allowable combustion time setting means is further provided to the user of the gas combustion device in the room. Ventilation is promoted, and the need for maintenance of the equipment is notified, and the use of this equipment is easy to use.

[0016]

According to the gas combustion device of the present invention having such a structure, first, according to the first invention, the combustion state is detected by the incomplete combustion prevention detection sensor means in the combustion state of the device, and this detection is performed. When an abnormality in the combustion state is detected by the output signal from the sensor means, the combustion stopping means operates to stop the combustion, but the output value of the detection sensor means is read by the sensor output value reading means during the operation. In addition, the actual continuous combustion time is measured by the combustion time measuring means (even if the combustion time from the start of operation at this time is measured, the combustion time after the combustion enters a stable state is measured. The output operation level of the detection sensor means for operating the combustion stopping means is changed by the operation level changing means according to the counted combustion time. Then, the combustion is stopped when the sensor output value read by the sensor output value reading means reaches the output operation level changed by the operation level changing means. If the advance warning means is provided, an alarm will be issued shortly before the changed output operation level is reached, and if the combustion stop warning means is provided, an alarm will be issued when the changed output operation level is reached. Will be emitted.

According to the second aspect of the present invention, the combustion state is detected by the incomplete combustion prevention detection sensor means in the combustion state of the equipment, and the combustion state is obtained by the output signal from the detection sensor means. When the abnormality is detected, the combustion stopping means operates to stop the combustion, but the output value of the detection sensor means is read by the sensor output value reading means during the operation thereof, and from the read sensor output value. The allowable continuous combustion time is set by the allowable combustion time setting means. Further, the actual continuous combustion time is measured by the combustion time measuring means, and the combustion is stopped when the measured combustion time reaches the allowable continuous combustion time set by the allowable combustion time setting means. .

Also in the case of the present invention, if the advance warning means is provided, the warning is issued shortly before the combustion time reaches the allowable continuous combustion time, and if the combustion stop warning means is provided, the combustion time is reached. An alarm will be issued when the maximum allowable continuous combustion time is reached.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the drawings. FIG. 1 shows a schematic configuration of a gas water heater to which the present invention is applied. As shown,
The gas water heater 10 includes a heat exchanger 12 including a water supply pipe 16 and a hot water discharge pipe 18 in the main body of the appliance, and the heat exchanger 12
And a gas burner 14 for heating the. On the other hand, a water stop cock 20 is connected to the water supply pipe 16, and a gas supply plug 24 is connected to the source of the gas pipe 22 for supplying gas to the gas burner 14. A water faucet pilot valve 26 is provided on the water stop cock 20, and the water faucet pilot valve 26 is driven by a motor 28 to operate the interlocking lever 3.
When opened through 0 and 32, water is adapted to flow through the water supply pipe 16.

A gas supply plug 24 provided in the gas pipe 22 of the gas burner 14 is provided with an automatic gas valve 34 which is opened in association with the flow of water into the water supply pipe 16 and an ignition trouble or the like. A magnet safety valve 36 and a device stopper 38 provided to open and close the gas supply passage are provided.

The faucet pilot valve 26 and the automatic gas valve 34 are connected to each other through the valve shaft 40 or the like, and when the faucet pilot valve 26 is opened to flow water,
The automatic gas valve 34 is designed to be opened automatically.

The magnet safety valve 36 is connected to the motor 28.
The valve actuating rod 42 is pushed by the driving of, and the magnet holding current flows and is excited, whereby the valve operating rod 42 is held in the open state. Then, after the magnet safety valve 36 is held open, the instrument plug 38 is then opened by driving the motor 28, whereby the gas supply passage in the gas supply plug 24 is completely opened, and gas is supplied to the gas burner 14. At the same time, the gas burner 14 is ignited by the continuous spark of the ignition electrode 44 accompanying the ON operation of the igniter 43.

Further, the cam switch 4 is provided close to the motor 28.
6, 48 are provided, and the combination of the ON / OFF signals of the cam switches 46, 48 associated with the driving of the motor 28 causes the faucet pilot valve 26 of the water stopcock 20 to be opened, and the magnet safety valve 36. Was held open by excitation, the instrument plug 38 was opened, and the water stopcock 20
The fact that the magnet safety valve 36 and the instrument stopper 38 are all closed is detected.

A water flow detection switch 50 is provided near the valve shaft 40 connecting the faucet pilot valve 26 and the automatic gas valve 34, and the water flow detection switch 50 is turned on by the movement of the valve shaft 40. As a result, the flow of water in the water supply pipe 16 is detected, and the ON signal of the water flow detection switch 50 starts the driving of the motor 28 and the ignition operation of the gas burner 14 by the igniter.

A hot water supply button 54 and an ignition switch 56 which is turned on by pressing the hot water supply button 54 are provided on an operation panel (not shown) of the instrument body, and the reference numeral 58 indicates the gas burner 1.
4 shows a primary thermocouple for detecting extinction of 4 and oxygen deficiency,
Further, reference numeral 60 denotes a secondary thermocouple provided to prevent incomplete combustion due to the fin clogging of the heat exchanger 12.

FIG. 2 is a block diagram showing a schematic structure of the gas water heater 10. The same components as those shown in FIG. 1 are designated by the same reference numerals and their detailed description will be omitted, but as shown in the figure, the water supply pipe 1
6, a water stopcock 20 and a gas supply system passage (gas pipe 2
2) Magnet safety valve 36 and device stopper 3
Each of 8 is connected to a motor 28. Further, the motor 28 and the water flow switch 50 described above are connected to the burner controller 6
2 is connected. An ignition switch 56 is connected to the burner controller 62, and further the thermocouple 5 described above is connected.
Both 8 and 60 are also connected. Furthermore, the burner controller 62 is provided with a warning alarm 64 that warns the user of this device in advance by a buzzer that the combustion stop state is approaching, and a combustion stop alarm 66 that notifies the user that the combustion has stopped. Connected as needed.

In this embodiment, the primary thermocouple 58 and the heat exchanger 1 provided near the gas burner 14 described above.
The secondary thermocouple 60, which is provided close to the second thermocouple 60, is connected in the direction of plus (+) / minus (−) in the opposite direction, and the electromotive force (V ₁ ) generated in the primary thermocouple 58 changes from the secondary thermocouple. 60 electromotive force generated by (V ₂₎ by subtracting the electromotive force (V
_1- V ₂ ) is sent to the burner controller 62 as a signal.

Then, in the burner controller 62, a combined electromotive force (V ₁ − of the primary thermocouple 58 and the secondary thermocouple 60).
If V ₂ ) decreases, the flame of the gas burner goes into a state of extinguishing due to a lift phenomenon or the like, or the heat of the combustion exhaust increases due to fin clogging of the heat exchanger, resulting in incomplete combustion. To judge. Then, when the burner controller 62 sends a command signal to the motor 28, the motor 28 is driven and stopped. At the stop position of the motor 28, the magnet safety valve 36 and the instrument stopper 38
Both are closed and the risk of gas leakage when incomplete combustion occurs is avoided.

Next, various embodiments of the gas combustion equipment to which the present invention is applied will be described in order. First of all,
FIG. 5 shows a first embodiment of the present invention.
This is to change the output operation level (comparison threshold value) for stopping the combustion of the incomplete combustion prevention detection sensor according to the continuous combustion (operating) time of the combustion state.
Explaining the control block diagram of FIG. 3, the combined electromotive force value of the primary thermocouple 58 and the secondary thermocouple 60 is detected by the thermoelectromotive force level detection circuit 70.

On the other hand, at the same time as the operation of the gas combustion equipment is started, the combustion time is measured by the timer drive circuit 74, and the thermocouple synthesis trigger for stopping the combustion is generated in accordance with the combustion time measured by the timer drive circuit 74. The power threshold value (operation level) is detected by the sensor operation level changing circuit 76.
Will be changed. Then, the operation level changed by the operation level changing circuit 76 and the thermoelectromotive force detection circuit 7 described above.
The combined electromotive force value of the thermocouple detected by 0 is determined in the combustion continuity propriety determination circuit 78, and the combined electromotive force value of the thermocouple in this combustion continuity propriety determination circuit 78 is the operation level (threshold value ) Has not been reached, that is, if it is determined that the combined electromotive force value exceeds the operating level, combustion continues, and the combined electromotive force value reaches the operating level (lowering). If judged,
The energization of the magnet safety valve 36 of the safety valve drive circuit 80 is cut off and the gas flow path is closed.

FIG. 4 shows a specific electric circuit diagram for realizing the control block diagram shown in FIG. However, it goes without saying that in the electric circuit diagram shown in FIG. 4, the combustion (operating) time can be similarly configured by a digital type or an analog type by a microcomputer or the like.

Therefore, in the electric circuit diagram shown in FIG.
A plurality of voltage dividing circuits for setting a reference voltage corresponding to the detection level of the non-combustion prevention detection sensor (thermocouple) are provided at the negative (-) input terminal of the comparator 90 serving as the combustion continuity determination circuit 78 (a in this embodiment. And two voltage dividing circuits of b are prepared). Then, the plurality of non-combustion prevention detection levels are sequentially switched as the combustion time elapses. Specifically, the charging time of the capacitor 91 is used in the continuous combustion time counting circuit 74, and the transistor T _r1 is turned on and the transistor T _r2 is turned off until the charging voltage reaches a predetermined value by the comparator 92.
After the charging voltage reaches a predetermined value, the transistor T _r1 is turned off.
F and T _r2 are _turned on. Therefore, the reference voltage of the comparator 90 that determines the non-combustion prevention detection level is switched.

FIG. 5 is a timing chart for explaining the operating state of each member in the electric circuit diagram shown in FIG. As shown in the figure, the incomplete combustion prevention detection level of a is selected until Ta seconds have elapsed from the start of combustion (ignition), and the incomplete combustion prevention detection level of b is selected after Ta seconds. The detection level of a is a relatively high value as the input value of the comparator 90, while the detection level of b is a relatively low value as the input value of the comparator 90. Therefore, when the time after gas ignition elapses, it is considered that the magnet safety valve 36 is closed earlier against the deterioration of the combustion state, that is, against the decrease of the combined thermoelectromotive force value of the thermocouple. .

FIGS. 6 and 7 show an example of microcomputer control as a modification of the embodiment shown in FIGS. 3 to 5 described above. Further, in this modified example, the operation of the advance warning device 64 is also referred to.

First, the control flow chart of FIG. 6 will be described. When the hot water supply button 54 is turned on, combustion (operation) is started (step 1, "S1" in the figure).
Is written), the timer is activated and the clocking of the operating time is started (S2). And in parallel with that, the primary thermocouple 58
And the combined electromotive force value (X _n ) by the two detection sensors of the secondary thermocouple 60 are continuously read (S3).

In such an operating state, whether or not the change of the combined electromotive force value (X _n ) of the detection sensor is larger than a certain value, that is, the combined electromotive force value (X _{n- 1} ) read immediately before is detected. It is determined whether or not the combustion state is stable by determining whether or not the difference is less than or equal to a predetermined value (S4). Then, when the combined output value of the detection sensor is greatly increased, it is determined that the stable period of the combustion state has not yet been entered, that is, the combustion initial stage (S4, "NO"), and the reading of the output value of the detection sensor is continued. However, if it is determined that the stable combustion state has been entered (S4, “YES”), then the above-mentioned timer (t) that is being timed (counted) is read (S5), and an alarm is also issued. The level (K _t ) and the combustion stop level (S _t ) are set (S6). The "alarm level" here means that incomplete combustion occurs and combustion (operation) occurs.
Refers to the combined electromotive force value of the detection sensor when notifying the user of this device that it is about to stop, and the "combustion stop level" is the combined electromotive force of the detection sensor when stopping combustion due to incomplete combustion. Refers to the power value.

FIG. 7 is a table showing the relationship among the timer value (t), the alarm level (K _t ) and the combustion stop level (S _t ). As shown in this table, the alarm level (K _t ) and the combustion stop level (S _t ) are divided into several stages according to the value of the timer (t) and the reference is provided. As the timer (t) value increases, the alarm level ( _Kt ) and the combustion stop level ( _St ) increase, and the TC output threshold value of the detection sensor increases. This is because the longer the operating time since the start of combustion (operation), the more the air pollution in the room (decrease in oxygen concentration) progresses, or the poor ventilation of the room causes an early warning. It is due to the judgment that it is necessary to start the combustion and stop the combustion. Also, the longer the operating time, the greater the impact on the human body due to slight air pollution.
On the contrary, if the operating time after starting combustion (operation) is short, the air pollution in the room has not progressed so much,
It is judged that it is not necessary to stop the operation unless the TC output value drops significantly because the ventilation condition of the room is not bad.

In the table shown in FIG. 7, the alarm level (K _t ) and the combustion stop level (S _t ) are raised stepwise by the timer (t) value, but of course, this may be a function of time. K _t = f (t), S _t = f (t)

Next, returning to the flow chart of FIG. 6, when the alarm level (K _t ) and the combustion stop level (S _t ) are set according to the timer value (S6) in this way, the thermocouple (detection) is naturally detected. It is determined whether the combined electromotive force value (X _n ) of the sensor has always reached the alarm level (K _t ) (S7), and if it is determined that the alarm level (K _t ) has been reached (S7, “ Y
ES "), and then the combined electromotive force value (X _n ) of this detection sensor
Has reached the combustion stop level (S _t ) (S8). Here, the combustion stop level (S _t ) is set to an output threshold value slightly lower than the alarm level (K _t ), so it is determined to be “NO”, and the advance warning alarm 64 sounds and the appliance user is warned. It is evoked (S9).

Then, returning to S3 again, the combined output value (X _n ) of the detection sensor is read, but if it is judged in S8 that the combustion stop level (S _t ) has been reached (S8, "YE").
S "), the combustion (operation) is stopped, and the advance warning device and the timer are stopped (S1).
0). At this time, the combustion (operating) time elapses every moment from the sounding of the advance warning device 64 (S9) to the stop of combustion (S10), and the value (X _n ) read by the timer in S5 during that time. Changes, the value of the combustion stop level (S _t ) at S8 also changes accordingly.

FIG. 8 is a flowchart of S in the flowchart shown in FIG.
The part 10 is shown as yet another embodiment. In the flow chart shown in FIG. 8, a reset button (not shown) for stopping the alarm is provided in this device, and when the combined output value (X _n ) of the detection sensor reaches the combustion stop level (S _t ). Stop combustion (S11)
However, it is then determined whether or not the reset button has been pressed (S12), and if it is determined that the reset button has been pressed (S12, "YE"
S "), the alarm device is stopped.

Next, FIGS. 9 to 12 show another embodiment of the present invention. This is to change the allowable continuous combustion (operation) time according to the output signal value of the incomplete combustion prevention detection sensor.

Explaining the control block diagram of FIG. 9, the combined electromotive force value (output value) of the primary thermocouple 58 and the secondary thermocouple 60 is detected by the thermoelectromotive force detection circuit 70, and this sensor output value changes with time. When the change becomes small, the thermoelectromotive force stable state determination circuit 72 determines that the combustion state has entered the stable period. Based on the determination result, the combined electromotive force detected by the thermoelectromotive force detection circuit 70 next. Based on the value (output value), the allowable single continuous combustion (operation) time of this gas combustion device is preset by the computer, and when this combustion time elapses, this gas combustion device will be connected to the magnet safety valve 36. Is automatically shut off, but this one continuous operation time is changed by the allowable continuous combustion time setting circuit 82.

On the other hand, the combustion time is measured by the timer drive circuit 74 at the same time as the operation of the gas combustion equipment is started, and the comparison between the combustion time measured by the timer drive circuit 74 and the above-mentioned changed continuous combustion time is made. Whether or not to continue the combustion is determined by the combustion continuity determination circuit 78. If the combustion continuity determination circuit 78 determines that the combustion time has not yet reached the changed continuous combustion time, the combustion is continued, and if the combustion time reaches the changed continuous combustion time, The safety valve drive circuit 80 is driven to shut off the magnet safety valve 36.

FIG. 10 shows a concrete electric circuit diagram for realizing the control block diagram shown in FIG.
However, needless to say, in this electric circuit diagram, the combustion (operating) time can be measured not only by a digital type such as a microcomputer but also by an analog type. Further, in this electric circuit diagram, the thermocouple (58.60) is connected to the A of the microcomputer 100.
/ D input port and captures the combined electromotive force value as a digital value. Then, the combustion limit time T _L [minutes] is determined by a table or a function in the microcomputer from the electromotive force value taken in. Then, the time T [minutes] counted from the start of combustion is compared with _TL [minutes] to determine whether to continue combustion. If T ≧ _TL , the magnet safety valve 36
Is turned off to extinguish the fire.

FIG. 11 is a flow chart for explaining the operation of this embodiment. This will be described. When combustion (operation) is started, the initial value of the first allowable continuous combustion (operation) time is set first, and then the operation time measurement (T) is started (S21). However, in parallel therewith, the combined electromotive force value by the two detection sensors of the primary thermocouple 58 and the secondary thermocouple 60 is read over time (S2
2) The allowable single continuous combustion (operation) time ( _TL ) is determined from the output value of the detection sensor (S23).
Note that the thermoelectromotive force stable state determination circuit 72 prevents the above operation from being performed when the combined electromotive force at the time of ignition rises.

FIG. 12 shows the relationship between the combined output value of the detection sensor and the allowable continuous combustion time. The higher the detection sensor output value, the longer the allowable continuous operation time (T _L ). . This means that the higher the output value of the detection sensor, the less the air in the room is polluted (decrease in oxygen concentration) or the state where ventilation in the room is not bad. This is due to the judgment that they can feel reassured. On the other hand, if the detection sensor output value is low, there is a safety problem such as that the air in the room is contaminated or the room is not well ventilated. is there.

After the continuous operation time (T _L ) is determined in S23, it is constantly judged whether or not the operation time (T) from the start of operation reaches T _L (S2
4) As long as _TL is not reached, it continues, but at that time ( _TL ), the magnet safety valve 36 is turned off (OFF) to extinguish the fire, and the operation is stopped.

Next, FIGS. 13 to 16 show the above-mentioned FIGS. 9 to 1.
This is shown as a further modification of the embodiment shown in FIG. This is one in which the output signal values of the incomplete combustion prevention detection sensor are integrated and whether or not combustion can be continued is determined based on this integrated value.

Referring to the control block diagram of FIG. 13, the combined electromotive force value (output value) of the primary thermocouple 58 and the secondary thermocouple 60 is detected by the thermoelectromotive force detection circuit 70, and this sensor output value changes with time. When the change becomes small, the thermoelectromotive force stable state determination circuit 72 determines that the combustion state has entered the stable period. Based on the determination result, the combined electromotive force detected by the thermoelectromotive force detection circuit 70 next. The values (output values) are sequentially integrated in the integrating circuit 84. Actually, the difference between a certain fixed value (a value that allows combustion) and its integrated value is calculated. Then, the combustion continuity determination circuit 78 determines whether or not to continue the combustion based on the value of the difference. If the combustion continuity determination circuit 78 determines that the combustion stop state has not been reached yet, the combustion is continued, and if it is determined that the combustion stop state has been reached, the safety valve drive circuit 80 Magnet safety valve 36
However, in this embodiment, a notice warning determination circuit 86 is further connected to the combustion continuity determination circuit 78, and if it is determined that the state of stopping combustion is approaching, a notice is given. The alarm device 64 sounds to alert the user, and when the combustion is stopped, the combustion stop alarm 66 is activated and the alarm also sounds.

FIG. 14 shows a specific electric circuit diagram for realizing the control block diagram shown in FIG. Although detailed explanation is omitted, in this electric circuit diagram, the thermocouple (58.60) is referred to as A of the microcomputer 100.
/ D input port and captures the combined electromotive force value as a digital value. Then, after determining that the stable combustion state has been entered from the incorporated electromotive force value, the difference between the predetermined electromotive force value X _O and the incorporated electromotive force value X _n is integrated, and this integrated value is calculated. When a predetermined value Y _k which is an alarm level is reached, a combustion stop advance warning is given, and when a predetermined value Y _s which is a combustion stop level is reached thereafter, combustion is stopped and a stop alarm is given.

FIG. 15 shows a control flow chart thereof. To explain this, combustion (operation) is started by the ON operation of the hot water supply button 54 (S3).
When 1), the timer is activated and the clocking of the operating time is started (S32). In parallel with this, the combined electromotive force value (X _n ) by the two detection sensors of the primary thermocouple 58 and the secondary thermocouple 60 is read with time (S33).

Then, the combined electromotive force value (X _n ) of the detection sensor
It is determined whether the combustion state is stable (S34), and if it is determined that the stable combustion state has been entered (S34, "YES"), then the thermocouple (detection) is detected. the difference between the constant value (X _o) synthesis electromotive force of the sensor) (X _n) is what is written over time to read (X _n -
X _o ) are sequentially added up (S35). Then, it is determined whether or not the integrated value (Y) has reached the alarm level (Y _k ) (S36), and if it is determined that the alarm level (Y _k ) has been reached (S36, "YES"), then Then, it is judged whether or not the integrated value (Y) has reached the combustion stop level (Y _s ) (S3).
7) The advance warning alarm 64 sounds and the appliance user is alerted (S38).

If it is determined that the integrated value (Y) has reached the combustion stop level (Y _s ) in S37 (S37,
"YES"), combustion (operation) is stopped, and the alarm device is also stopped (S39).

FIG. 16 shows the relationship between the operating time (T) and the combined output value of the detection sensor. The composite output value of the detection sensor is integrated after the operation is started and combustion is stabilized, but this difference (X _o −X _n ) is small in comparison with a certain reference output value (X _o ). At this time, the air in the room is less polluted (decrease in oxygen concentration) or the fins of the heat exchanger are less clogged, and as the combined electromotive force decreases (X _o −X _n ) increases. Since it is judged that the air in the room is contaminated or the fins of the heat exchanger are starting to become clogged, (X
_The value obtained by integrating _o −X _n ) with time is considered to be a factor that can quantitatively judge the degree of air pollution.

Also in the case of this embodiment, although not shown, when the integrated value (Y) reaches the combustion stop level (Y _s ) and the combustion is stopped, the alarm keeps sounding and an alarm device is activated by a reset button or the like. It may be stopped.

Although various embodiments have been described above, the gist of the present invention is that the air in the room is contaminated (decrease in oxygen concentration) or the room air is contaminated when the open type gas combustion apparatus of this type is operating. When incomplete combustion starts due to poor ventilation, the longer the combustion (operation) time, the higher the sensor threshold value (operation level) that stops combustion, or the lower the sensor output value that is detected. Combustion is stopped early by shortening the continuous operation time, while the sensor threshold value (operation level) for combustion stop is lowered when the combustion time is short,
Alternatively, the higher the detection sensor output value is, the longer the continuous operation time is to delay the combustion stop. Thus, the operation of the gas combustion device is appropriately continued or stopped in consideration of the usage environment (room size, ventilation, etc.).

Therefore, it goes without saying that various modifications and improvements can be made without departing from the spirit of the present invention. For example, as a combustion state detection sensor, it is possible to use a gas sensor or the like instead of a thermocouple, and it is changed according to the combustion stop operation level of the detection sensor or the detection sensor output value that is changed according to the operating time. It would also be possible to make it continuous and stepless without changing the continuous operation time. Further, a gas type switching switch or the like may be provided so that the operation level of the detection sensor and the relationship between the sensor output value and the combustion time can be changed according to the gas type used. Further, instead of the control by the magnet safety valve, the opening / closing control of the solenoid valve may be used. Further, the present invention is not limited to the water heater, but can be applied to various open combustors such as a stove.

[0059]

As is apparent from the above description, according to the open type gas combustion device of the present invention, incomplete combustion is caused depending on the environment (room size, ventilation, etc.) in which the device is used. If the combustion stop timing is properly determined when the start of combustion occurs, it can be used in a state where the combustion stop is not too early and not too late, so safety in using the device is secured, and Combustion stop due to malfunction is also avoided, and the usability is improved. Therefore, it is extremely beneficial to apply this to an open type gas water heater or the like having a conventional incomplete combustion device in terms of improving safety.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a main stop type gas water heater as an example of an open type gas combustion apparatus to which the present invention is applied.

FIG. 2 is a schematic block diagram showing a block diagram of a main part of the configuration of the gas combustor shown in FIG.

FIG. 3 is a control block diagram as one embodiment of the present invention.

FIG. 4 is a specific electric circuit diagram for realizing the embodiment shown in FIG.

5 is a timing chart for explaining the operation of each member in the electric circuit of the embodiment shown in FIG.

FIG. 6 is a flow chart as another embodiment of the present invention.

7 is an explanatory diagram of the flowchart shown in FIG.
It is a figure showing the relation between the operating time and the alarm level or the combustion stop level of the detection sensor output value.

FIG. 8 is a flowchart as a modification of the flowchart shown in FIG.

FIG. 9 is a control block diagram as another embodiment of the present invention.

FIG. 10 is a specific electric circuit diagram for realizing the embodiment shown in FIG.

FIG. 11 is a flowchart for carrying out the invention of the embodiment shown in FIG.

FIG. 12 is a diagram showing the relationship between the detection sensor combined output value and the continuous combustion time in the explanation of the flowchart shown in FIG. 11.

FIG. 13 is a control block diagram as still another embodiment of the present invention.

FIG. 14 is a specific electric circuit diagram for implementing the embodiment shown in FIG.

15 is a flow chart for carrying out the invention of the embodiment shown in FIG.

16 is a diagram showing the relationship between the operating time and the combined thermoelectromotive force output value of the detection sensor in the explanation of the flowchart shown in FIG.

FIG. 17 is a structural explanatory view of an incomplete combustion prevention device in this type of gas combustion device that is generally known in the past.

FIG. 18 is a control block diagram as a conventional example.

19 is a specific electric circuit diagram for realizing the conventional example shown in FIG.

20 is a timing chart for explaining the operation of each member in the electric circuit of the conventional example shown in FIG.

[Explanation of symbols]

 10 original stop type gas water heater 36 magnet safety valve 58 primary thermocouple 60 secondary thermocouple 64 warning alarm 66 combustion stop alarm 70 thermoelectromotive force detection circuit 74 continuous combustion (running) time clock circuit 76 detection sensor level change circuit 78 Combustion continuity possibility determination circuit 80 Safety valve drive circuit 82 Allowable continuous combustion (operation) time change circuit 84 Detection sensor output value integration circuit 86 Advance warning determination circuit

Claims (6)

[Claims] 1. An incomplete combustion, comprising incomplete combustion prevention detection sensor means for detecting a combustion state, and combustion stop means for stopping combustion when an abnormality in the combustion state is detected by an output signal from the detection sensor means. In an open-type gas combustion device with a prevention device, a sensor output value reading means for reading the output value of the detection sensor means, a combustion time counting means for measuring an actual continuous combustion time, and a combustion time measured according to the combustion time. And an operation level changing means for changing the output operation level of the detection sensor means on which the combustion stopping means operates, and the output operation in which the sensor output value read by the sensor output value reading means is changed by the operation level changing means. An open type gas combustion device with an incomplete combustion prevention device, characterized in that combustion is stopped when the level is reached. 2. The system further comprises advance warning means for issuing an alarm shortly before the sensor output value read by the sensor output value reading means reaches the output operation level changed by the operation level changing means. An open type gas combustion device with an incomplete combustion prevention device according to claim 1. 3. A combustion stop alarm means for issuing an alarm when the sensor output value read by the sensor output value reading means reaches the output operation level changed by the operation level changing means. An open type gas combustion device with an incomplete combustion prevention device according to claim 1 or 2. 4. An incomplete combustion including an incomplete combustion prevention detection sensor means for detecting a combustion state, and a combustion stopping means for stopping combustion when an abnormality in the combustion state is detected by an output signal from the detection sensor means. In an open type gas combustion device with a prevention device, a sensor output value reading means for reading the output value of the detection sensor means, and an allowable combustion time setting means for setting an allowable continuous combustion time from the read sensor output value. A combustion time measuring means for measuring an actual continuous combustion time, and combustion when the combustion time measured by the combustion time measuring means reaches the allowable continuous combustion time set by the allowable combustion time setting means. An open-type gas combustion device with an incomplete combustion prevention device, characterized in that it is configured to be stopped. 5. The system further comprises advance warning means for issuing an alarm shortly before the combustion time measured by the combustion time measuring means reaches the allowable continuous combustion time set by the allowable combustion time setting means. An open type gas combustion device with an incomplete combustion prevention device according to claim 4. 6. A combustion stop alarm means for issuing an alarm when the combustion time measured by the combustion time measuring means reaches the allowable continuous combustion time set by the allowable combustion time setting means. An open type gas combustion device with an incomplete combustion prevention device according to claim 4 or 5.