KR100250395B1 - Non-complete combustion prevention device for gas hot water heater - Google Patents

Abstract

(assignment)

Provided is an incomplete combustion prevention device for a gas cooker that immediately responds when there is a lack of oxygen in the environment, or when a heat exchanger is blocked.

(Solution)

The burner controller 30 applies a voltage to the frame rod 38 located in the salt generated in the salt ball in the normal combustion state above the salt ball 22 of the burner 20, and the detected salt current is less than or equal to a predetermined determination value. The gas solenoid valve 26 which supplies fuel gas to a burner is closed. The reflux tube 13 has a return pipe portion 13b having an upper end portion open to the combustion chamber under the heat exchanger 12 and open toward the salt port 22 provided with a frame rod 38 under the heat transfer skirt 10. Install it. When the heat exchanger is blocked, the combustion waste gas in the upper part of the combustion chamber passes through the reflux tube 13 and returns to the vicinity of the salt port 22. It is preferable that the reflux tube extends substantially vertically downward to be composed of the main body portion 13a having the lower end released and the return tube portion 13b branched in the middle thereof.

Description

Incomplete combustion prevention device of gas cooker

(Technical field of invention)

The present invention relates to an incomplete combustion prevention device for use in a gas stove to heat the heat exchanger installed above the inner copper skirt with a burner.

(Conventional technology)

The incomplete combustion prevention device for this type of gas stove is, for example, disclosed in Japanese Patent Application Laid-Open No. 61-18358, in which a thermocouple is placed at a position where salts are generated in a normal combustion state above a burner salt ball. When the output static pressure of the thermocouple falls below a predetermined determination value, the gas solenoid valve for supplying fuel gas to the burner is closed, and an opening is provided in the upper portion of the refrigeration skirt (lower side of the heat exchanger). Some thermocouples may be removed and the thermocouples may be connected in reverse characteristics. In the case where the gas heater is installed indoors, if the oxygen concentration in the house continues to be used in an insufficient state of exhaust, the combustion state is incompletely burned, thereby causing the burner flame to lift, and the length of the unburned gas portion of the flame relief portion. Becomes large. Accordingly, in the incomplete combustion prevention device, since the thermocouple enters the unburned gas portion and the output voltage decreases, the incomplete combustion caused by the deficiency is prevented by closing the gas solenoid valve and stopping the supply of combustion gas to the burner.

In addition, if the amount of combustion air is insufficient due to blockage of a heat exchanger installed on the inner side of the inner skirt, incomplete combustion occurs even if the oxygen concentration in the installation environment is normal. Thermocouples (primary thermocouples) alone cannot prevent incomplete combustion due to this cause. In order to solve this problem, in addition to the primary thermocouple installed above the burner ball, the secondary thermocouple facing from the outside is provided in the opening provided in the inner side of the inner skirt upper side. When the combined output voltage falls below a predetermined determination value, the gas solenoid valve for supplying fuel gas to the burner is closed.

In this technique, since there is almost no combustion gas leakage from the upper side wall opening of the inner movable skirt in a state where a heat exchanger or the like is not clogged, the thermocouple output voltage working there is almost zero, and the thermocouple voltage installed above the burner flame opening Will actually output 2 outputs. Therefore, when the oxygen concentration in the room decreases, incomplete combustion is prevented by the same effect as described above. If a blockage occurs in a heat exchanger or the like, the pressure in the upper portion of the inner movable skirt rises and the combustion gas flows out of the opening, so that the thermocouple facing the opening is heated to increase its output voltage and the synthesized output voltage decreases accordingly. When it becomes below, the combustion gas supply to a burner is stopped. This also prevents incomplete combustion due to clogging of heat exchangers and the like.

(Tasks to be solved by the invention)

Although the above technique satisfies a set of functions, the thermocouple has a certain heat capacity and thus causes a delay in heating and cooling, which causes a delay in response. In particular, thermocouples installed above the burners are also used to detect burnout of burners at the start of operation of gas stoves, but a delay of several seconds (for example, 10 seconds) is required for detection of burnouts by thermocouples. In the case of non-combustion, the emission time of unburned gas is long. In order to solve this problem, the detection of the incombustibility to the burner is performed by detecting the salt current by a frame rod provided separately from the thermocouple. However, since both the thermocouple and the frame rod are used, there is a problem of high cost. Further, in the above prior art, it is conceivable to replace the thermocouple provided above the burner ball with a frame rod, but it is essentially impossible to replace the thermocouple facing the opening of the inner side skirt upper side wall in the prior art with the frame rod. Therefore, although such substitution can prevent incomplete combustion due to insufficient oxygen concentration in the room, unstable combustion due to clogging of a heat exchanger or the like cannot be prevented.

The present invention aims to solve each of these problems.

BRIEF DESCRIPTION OF THE DRAWINGS The whole structure display figure of one Embodiment of the incomplete combustion prevention apparatus of the gas stoveware according to this invention.

FIG. 2 is a top view of an enlarged part of a main part indicated by line 2-2 of FIG. 1;

3 is a burner controller configuration diagram of the display embodiment of FIG. 1;

4 is a diagram showing a salt current and an incomplete combustion degree with respect to the oxygen concentration in the display embodiment of FIG. 1;

Fig. 5 is a view showing the temporal change of the salt current from the start of operation in the case where the closing ratios are different in the display embodiment of Fig.

* Description of the symbols for the main parts of the drawings *

10: inner skirt 12: heat exchanger

13: Reflux tube 13a: main body

13b: return tube 20: burner (main burner)

22: salt ball 26: gas solenoid valve

30: burner controller 38: frame load

(Means to solve the task)

The incomplete combustion prevention device of a gas water heater according to the present invention includes a heat exchanger in which the inner movable skirt is continuously installed above the inner dynamic skirt, and a burner installed in the lower portion of the inner dynamic skirt, and heats the water supply passing through the heat exchanger by the burner. It relates to a gas scrubber, which has a frame rod located in the salt generated in the copper ball in the normal combustion state above the burner, and a salt current passing through the frame rod is applied by applying a voltage to the frame rod. When the salt current is less than or equal to the predetermined value, the burner controller closes the gas solenoid valve for supplying fuel gas to the burner, and the frame rod is opened toward the salt ball provided with a frame rod at the lower end of the heat exchanger. And a reflux tube having a return pipe portion of the combustion waste gas.

If the oxygen concentration in the environment, such as a room equipped with a gas stove, becomes incomplete combustion state, a lift is generated in the flame of the burner, and the length of the unburned gas part of the flame source becomes long. As a result, when the frame rod enters the unburned gas portion, the salt current is immediately reduced in response thereto, and when this is less than the predetermined value, the burner controller closes the gas solenoid valve to stop the fuel gas supply to the burner. In addition, when the heat exchanger or the like is blocked, the upper pressure in the inner skirt is increased, so that the combustion waste gas of the portion is returned from the upper end of the reflux tube to the salt ball provided with the frame rod through the main body and the return tube. As a result, the oxygen supplied to the inlet portion is reduced, causing a lift in the flame of the portion, and the salt current decreases immediately in response to the same as above, and when the burner controller is below a predetermined value, the burner controller opens the gas solenoid valve. Close and stop the fuel gas supply to the burner. If the burner is not ignited for some reason at the start of operation of the gas cooker, there is no salt current passing through the frame rod, so the burner controller closes the gas solenoid valve and stops the fuel gas supply to the burner.

The reflux tube preferably extends downward substantially vertically from the upper end thereof, and has a lower end having a main body part freed outside the inner skirt and a return tube part branched in the middle of the main body part. When the burner is ignited, the pressure in the inner skirt is increased suddenly to increase the combustion waste gas flow returned from the reflux tube. However, most of this flow is discharged from the bottom of the reflux tube body, and The combustion waste gas returned to the side is slight. Therefore, the salt lift due to the return of the combustion waste gas to the salt ball at the time of ignition is small, and the ignition detection is not uncertain.

Embodiment of the Invention

The accompanying drawings show an embodiment in which the present invention is applied to a gas hot water dispenser.

As shown in FIG. 1, a heat exchanger 12 made of a heat transfer tube 12a and a fin 12b is provided above the inner movable skirt 10 forming the combustion chamber 14 of the gas instantaneous hot pot. Burner 20 is installed. The inlet side of the heat transfer tube 12a is connected to the water supply pipe 15 through a preheating tube 11 wound on the inner side of the inner skirt 10, and a hot water supply unit 17 is installed in the hot water supply tube 16 connected to the outlet side. It is. The water supply pipe 15 is provided with a water side controller 18 using a diaphragm for activating the hydraulic pressure actuating valve 28 and the water flow switch 31 which move the rod 18a and later when the water supply amount exceeds a predetermined amount. Although not shown, the water level controller 18 is provided with a manual valve for controlling the degree of tapping by manually adjusting the flow rate from the water supply pipe 15 to the heat exchanger 12.

As shown in FIG. 1, the main burner 20 is connected to three burner units 21. The gas solenoid valve 26, the capacity adjusting valve 27, and the hydraulic pressure actuating valve 28 are installed in series. Fuel gas is supplied through one gas supply pipe 25. The gas solenoid valve 26 is controlled to be opened and closed by the current flowing from the burner controller 30 to the operating coil 26a, and the capacity adjusting valve 27 is adjusted manually to adjust the gas supply amount to the main burner 20. It is to change the ability to tap the tangy. The hydraulic pressure control valve 28 is opened and closed by the rod 18a of the water side controller 18 so that the heat exchanger 12 is opened if there is a predetermined amount of water supply. When the hydraulic pressure actuating valve 28 is opened, the cam 18b provided on the rod 18a almost simultaneously turns on the water flow switch 31.

Each burner unit 21 is made of sheet metal, and has a plurality of salt balls 22 arranged in two rows, as shown in FIGS. 1 and 2, and each salt ball 22 is formed on a partition plate 22a. It is partitioned by. The reflux tube 13 main body portion 13a having the upper end opened to the upper part of the combustion chamber 14 through a hole provided in the side wall of the inner movable skirt 10 under the heat exchanger 12 is located outside the side wall of the inner movable skirt 10. Accordingly, the lower end is vertically extended and is opened into the atmosphere in the gas bath, and the return pipe portion 13b of the combustion waste gas branched in the middle passes through the notch formed in the inner movable skirt 10 so that the frame rod 38 It opens toward the salt ball 22 which forms the flame which is inserted. The frame rod 38 is supported by the insulator 38a so that its tip end is at a height that enters into the salt generated in the ball in the normal combustion state.

Next, the outline | summary of the burner controller 30 is demonstrated with FIG. In this embodiment, the power source 40 is a dry cell, and the voltage monitoring circuit 32, the solenoid valve driving circuit 33, the ignition circuit 34, the timer circuit 35, and the constant voltage circuit (31) are connected via the water flow switch 31. 36, the frame guard circuit 37 and the safety circuit 39 are connected. The solenoid valve driving circuit 33 receives the input from the timer circuit 35, flows a current into the operating coil 26a to open the solenoid valve 26, and operates the ignition circuit 34 to operate the ignition circuit 34a as described later. Ignited by the burner 20 and when the salt current detection value input from the frame guard circuit 37 is equal to or less than a predetermined determination value, the current to the operating coil 26a is stopped to close the gas solenoid valve 26. . The actuating coil 26a is a suction coil 26b that needs to flow a large current to open the closed gas solenoid valve 26, and a small current needs to flow in order to keep the thermoelectric gas solenoid valve 26 open. A retaining coil 26c is provided.

The frame guard circuit 37 receives a constant voltage output from the constant voltage circuit 36, applies a predetermined voltage to the frame rod 38, detects a salt current passing through the frame rod 38, and detects a signal corresponding to the value. This is output to the solenoid valve drive circuit 33. Since the salt current changes instantaneously in response to the change of the flame, the signal output to the solenoid valve driving circuit 33 can also be substantially performed without time delay. The frame guard circuit 37 is provided with a plug-in type gas type connector 37a in order to adjust the determination value according to the type of gas to be used. The safety circuit 39 monitors the operation of the frame guard circuit 37 for abnormality, and stops the operation of the gas cooker when an abnormality occurs. When the voltage of the current battery 40 falls below a predetermined limit, the voltage monitoring circuit 32 lights the indicator 32a to prompt battery replacement.

Next, the operation of the above embodiment will be described. When the hot water supply 17 is opened and the water supply passing through the water supply pipe 15 exceeds a predetermined amount, the water flow switch 31 is turned on at the same time as the water pressure response valve 28 is opened, and the burner controller 30 starts operation. First, the solenoid valve driving circuit 33 operates, opens a gas solenoid valve 26 which is closed by flowing a large current through the adsorption coil 26b, and releases the large current after a predetermined time (for example, for 2 seconds) to hold the holding coil 26c. A small current flows to the gas solenoid valve 26, and fuel gas is supplied to the main burner 20 while the gas solenoid valve 26 is kept open. At the same time that the water flow switch 31 is turned on, the ignition circuit 34 operates to generate sparks before the ignition 34a (not shown) installed near the flame port 22 of the burner 20 to eject the fuel from the main burner 20. After a short time of ignition of the gas and the stabilization of the fuel, the frame guard circuit 37 detects a salt current passing through the frame rod 38, and the ignition circuit 34 stops operation. If the detected salt current is less than or equal to the predetermined determination value, the combustion state is judged to be defective due to ignition miss or unsuccessfulness. The current to the holding coil 26c is stopped to close the gas solenoid valve 26, and the main burner ( Stop the operation of the gas cooker by stopping the fuel gas supply to 20).

When the main burner 20 is normally ignited, since the salt current passing through the frame rod 38 is greater than or equal to a predetermined value, the gas solenoid valve 26 continues to operate and the heat exchanger 12 remains open. The water supply passing through is heated by the main burner 20 to be hot-watered in the hot water supply 17. When the hot water supply 17 is closed, the hydraulic pressure actuating valve 28 is closed and the water flow switch 31 is turned off to stop the operation of the gas water heater. In the operating state, when the air in the environment where the gas scrubber is installed decreases the oxygen concentration or blocks the combustion air passage, the amount of combustion air is insufficient, resulting in incomplete combustion. The operation in each case will be described below.

First, although there is no blockage in the combustion air passage, the incomplete combustion prevention action when the oxygen concentration in the air decreases will be described. If the gas stove is installed indoors, continuing to use the gas stove without sufficient ventilation causes the indoor oxygen concentration to gradually decrease, resulting in incomplete combustion. When this is explained according to Fig. 4, as the oxygen concentration decreases, the ratio CO / CO ₂ indicating the degree of incomplete combustion increases with acceleration. In addition, as the oxygen concentration decreases, a lift occurs in the flame generated at the main burner 20, the salt balls 22, and the length of the unburned gas portion generated at the source of the flame gradually increases. As a result, in the normal combustion state, the tip of the frame rod 38 in the burning flame gradually moves to the unburned gas portion, so that the salt current gradually decreases as indicated by 1 in FIG. The frame guard circuit 37 detects this salt current 1 passing through the frame rod 38 and maintains the solenoid valve driving circuit 33 at the point A where the value becomes less than or equal to the predetermined determination value I ₀ . The current to the coil 26c is stopped to close the gas solenoid valve 26, and the supply of fuel gas to the main burner 20 is stopped to stop the operation of the gas stove. This determination value I ₀ is 1 µA, for example, and the value of the ratio CO / CO ₂ at that time is 0.035, for example. Incomplete combustion prevention when oxygen concentration in air falls is performed in this way. In this case, the combustion waste gas stream passing through the reflux tube 13 is substantially not generated.

Next, the oxygen concentration in the air is normal, but clogging due to combustion products or the like occurs in the heat exchanger 12 fin 12b provided on the inner side of the inner skid skirt 10, and the air flow deteriorates and the amount of combustion air is insufficient. Explain incomplete combustion prevention in cases.

As the blockage increases, the upper pressure in the combustion chamber 14 formed between the inner movable skirt 10 and the heat exchanger 12 and the main burner 20 gradually increases, but the conventional reflux tube 13 is not installed. For example, even if incomplete combustion occurs due to clogging of the heat exchanger 12 or the like, the salt generated in the salt ball 22 hardly lifts.

However, in the above embodiment in which the reflux tube 13 is provided, clogging due to combustion products or the like in the heat exchanger 12 increases, and as the pressure in the upper portion of the combustion chamber 14 rises, the main body portion of the reflux tube 13 is shown as a solid arrow. At 13a, the combustion waste gas in the upper part of the combustion chamber 14 which returns to the vicinity of the salt ball 22 which installed the frame rod 38 past the return pipe part 13b increases gradually. As a result, the oxygen concentration of the combustion air in the vicinity of the salt balls 22 is decreased, so that the salts generated in the salt balls 22 gradually lift, and the length of the unburned gas portion generated at the source of the flame gradually increases. As a result, in the normal combustion state, the salt current gradually decreases because the tip of the frame rod 38 in the burning flame gradually moves into the unburned gas portion. The frame guard circuit 37 detects this salt current passing through the frame rod 38, and when this value is less than or equal to the predetermined determination value I ₀ , the solenoid valve driving circuit 33 is a current for the holding coil 26c. To stop the fuel gas supply to the main burner 20 to stop the operation of the gas cooker.

In this embodiment, the determination value is also 1 µA, and the heat exchanger 12 passage area closing rate for stopping the gas water heater operation is adjusted by adjusting the shape dimension of the reflux tube 13, in particular, the shape dimension of the return tube portion 13b. We can choose appropriately.

Incomplete combustion prevention in the case of clogging the heat exchanger 12 is performed in this way.

FIG. 5 is a diagram showing the temporal change of the salt current from the start of operation in the gas water heater of the above embodiment in which the closing ratio of the heat exchanger 12 is different, whereby a blockage is caused in the heat bridge 12. The action of is described in more detail.

When the heat exchanger 12 is closed at 0% (no blockage), the salt current rapidly increases when it is ignited by the fuel gas at the start of operation, and then drops rapidly, and then increases and converges to a certain value.

The rapid decrease of the salt current after ignition means that when the burner 20 is ignited, the pressure in the inner movable skirt 10 increases momentarily and the flow of the combustion waste gas returned from the reflux tube 13 increases, which causes a momentary lift to the flame. In this embodiment, since most of this flow is discharged from the lower end of the main body portion 13a of the reflux tube 13 and the combustion waste gas returned from the return tube portion 13b toward the inlet 22 is slightly discharged. No big deal. However, if the return pipe portion 13b is formed by bending the lower portion of the reflux tube 13 to return all the combustion waste gas to the salt ball 22, the temporary drop in the salt current becomes considerably large.

As shown in FIG. 5, as shown in FIG. 5, the initial change of the salt current from the start of operation does not change much as the increase rate of the heat exchanger 12 increases, but gradually decreases when the closing rate increases to some extent. This is because, as described above, the amount of combustion waste gas returned from the return pipe portion 13b to the vicinity of the salt port 22 where the frame rod 38 is installed in the return pipe portion 13b increases, so that the lift of the flame increases. In the example of FIG. 5, when the closing rate reaches about 35%, the temporary drop of the salt current reaches the determination value Io. When the closing rate is higher than that, the solenoid valve driving circuit 33 closes the gas solenoid valve 26. Stop the gas stove operation.

In the said embodiment, the reflux pipe 13 main body part 13a is extended substantially vertically downward to release | release the lower end, and the return pipe part 13b is branching in the middle, according to this, the salt current just after ignition as mentioned above. Since the temporal decrease in the number of times is reduced, the ignition detection performed immediately after ignition does not become unstable. However, in the present invention, the return pipe portion 13b may be formed by bending the lower portion of the reflux tube 13 so as to return all the combustion waste gas to the salt ball 22.

In this case, the temporary decrease in the salt current immediately after ignition increases, but the ignition is detected before this temporary decrease occurs (e.g., 2 seconds from the start of the operation of the ignition circuit), and the incomplete combustion detection by the salt current is performed for a considerable time (for example, 1 minute). ) After the elapsed time.

The above embodiment has described an example in which the present invention is applied to a gas cooker of the type that directly ignites the main burner before ignition, but the present invention is also applicable to a gas cooker of the type that ignites the main burner by a pilot burner. In this case, the frame rod may be installed in the pilot burner, and the return pipe portion 13b of the reflux tube 13 may face the pilot burner. In addition, the present invention can be applied not only to the tip-locked type gas stove, but also to the base-locked type gas stove.

As described above, according to the present invention, the salt current is immediately lowered in response to both incomplete combustion when the oxygen concentration in the environment such as an indoor room is insufficient and incomplete combustion when clogging the heat exchanger or the like, which is below a predetermined determination value. The burner stops supplying combustion gas. Thus, incomplete combustion of the gas stove may be prevented without time delay. Further, even when ignition is not carried out to the burner, the fuel gas supply to the burner is immediately stopped in response to this, so that the unburned gas discharge time in the case of non-ignition can be shortened.

In addition, when the reflux tube body portion is extended substantially vertically downward to release the lower end, and branching the return tube portion in the middle thereof, the combustion waste gas returns to the salt ball due to the instantaneous increase in the pressure in the driving skirt at the time of ignition to the burner. As a result, since the lift of the flame is small, the ignition detection by the frame rod can be stably performed.

Claims (2)

A burner comprising: an inner copper skirt, a heat exchanger continuously installed above the inner copper skirt, and a burner provided at a lower portion of the inner copper skirt, wherein the water heater passing through the heat exchanger is heated by the burner. The flame burner located in the salt generated in the copper ball in the normal combustion state above the salt ball, and the salt current passing through the frame rod by applying a voltage to the frame rod to detect the salt current is below a predetermined determination value, the burner A burner controller for closing a gas solenoid valve for supplying combustion gas to the reflux, and a combustion waste gas return tube having an upper end opened into the inner movable skirt at the lower side of the heat exchanger and directed toward the salt port provided with the frame rod at the bottom thereof. Incomplete combustion prevention device of a gas stove, characterized in that provided with a tube. 2. The gas according to claim 1, wherein the reflux tube is composed of a main body portion extending downwardly substantially vertically from the upper end portion, the lower end of which is released outside the inner skirt, and the return pipe portion branched in the middle of the main body portion. Incomplete combustion prevention device of the scrubber.

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