JP2013044463A - Burning appliance - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suitably prevent the production of drain in an exhaust passage even if an air supply passage and the exhaust passage are adjacent to each other.SOLUTION: In a supply and exhaust tube 20, a communication hole 21 communicating with the air supply passage 18 is formed in the exhaust passage 5, and a venturi 22 for making the internal pressure of the exhaust passage 5 lower than the internal pressure of the air supply passage 18 and introducing a part of combustion air in the air supply passage 18 to the exhaust passage 5 through the communication hole 21 is provided at the upstream side of the flow of the combustion exhaust higher than the communication hole 21.

Description

  The present invention relates to a combustion appliance such as a water heater employing a forced supply / exhaust type (so-called FF type).

A combustion appliance such as a water heater is equipped with a fan to forcibly take in combustion air from the air supply passage to the burner and supply it to the burner, and to discharge the burner combustion exhaust from the exhaust passage to the outside of the appliance The type is known.
For example, in Patent Document 1, a double-pipe air supply / exhaust cylinder having an air supply passage formed on the outer periphery of an exhaust passage that discharges combustion exhaust from a burner is formed, and the air supply / exhaust cylinder is projected outside to form combustion air. Is disclosed in which intake of fuel and exhaust of combustion exhaust gas are performed.

Japanese Utility Model Publication No. 3-13062 (FIG. 1)

  If the air supply passage and the exhaust passage are provided adjacent to each other as in the invention of the above-mentioned Patent Document 1, drainage is generated in the exhaust passage because the high-temperature combustion exhaust and the low-temperature outside air exchange heat. May become white smoke. In addition, the generation of drain may lead to deterioration of the supply / exhaust cylinder and acceleration of corrosion. This drain is likely to occur especially in winter when the temperature difference is large.

  Therefore, the present invention has an object of providing a combustion appliance that can suitably prevent the generation of drain in the exhaust passage even when the supply passage and the exhaust passage are adjacent to each other. is there.

In order to achieve the above object, according to the first aspect of the present invention, a communication hole that communicates with the air supply passage is formed in the exhaust passage, and the air passage in the air supply passage is provided between the exhaust passage and the air supply passage. An air introducing means for moving a part of the combustion air from the communication hole to the exhaust passage is provided.
According to a second aspect of the present invention, in the configuration of the first aspect, the air introduction means is configured to make the flow velocity of the combustion exhaust gas in the exhaust passage faster than the flow velocity of the combustion air in the supply passage. It is what.
According to a third aspect of the present invention, in the configuration of the second aspect, the air introduction means is a venturi that is provided in the vicinity of the communication hole of the exhaust passage, and the passage area decreases from the upstream to the downstream of the flow of the combustion exhaust. It is characterized by this.
According to a fourth aspect of the present invention, in the configuration according to any one of the first to third aspects, the communication hole and the air introduction means are provided in a supply / exhaust cylinder having a double-pipe structure in which an air supply passage is formed on the outer periphery of the exhaust passage. It is provided.
According to a fifth aspect of the present invention, in the configuration of any one of the first to fourth aspects, the heat exchanger passes through the main heat exchanger that recovers sensible heat from the combustion exhaust of the burner, and the main heat exchanger. It comprises a sub heat exchanger that recovers latent heat from the combustion exhaust, and the combustion exhaust that has passed through the sub heat exchanger is discharged from the exhaust passage.

According to the first aspect of the present invention, the temperature of the combustion exhaust gas can be lowered and the humidity can be lowered by mixing the combustion air into the combustion exhaust gas by the air introduction means. Therefore, even when the air supply passage and the exhaust passage are adjacent to each other, it is possible to suitably prevent the generation of drain in the exhaust passage and to prevent white smoke.
According to the second aspect of the present invention, in addition to the effect of the first aspect, the air introduction means can be easily formed by adjusting the flow velocity of the combustion air and the combustion exhaust gas.
According to the third aspect of the invention, in addition to the effect of the second aspect, the air introduction means can be easily formed by the venturi.
According to the fourth aspect of the present invention, in addition to the effect of any one of the first to third aspects, the communication hole and the air introduction means can be simplified using the air supply / exhaust cylinder in which the exhaust passage and the air supply passage are adjacent to each other. Can be provided.
According to the fifth aspect of the present invention, in addition to the effect of any one of the first to fourth aspects, it is possible to further reduce the temperature of the combustion exhaust gas in the latent heat recovery type combustion appliance that originally has a low exhaust gas temperature. Therefore, synthetic resin can be used as the material for the exhaust passage, leading to low cost.

It is a schematic block diagram of a water heater. It is an expanded sectional view of an air supply / exhaust pipe. It is explanatory drawing of the example of a change. It is explanatory drawing of the example of a change.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a schematic configuration diagram of a water heater as an example of a combustion appliance. The water heater 1 includes a combustion chamber 3 provided with an air supply fan 4 on the lower side and an exhaust passage 5 on the upper side in the appliance main body 2. The burner 6 is formed inside the combustion chamber 3 to burn the mixed gas of the fuel gas and the combustion air from the air supply fan 4, and the sensible heat in the combustion exhaust from the burner 6 is mainly recovered. The fin tube type main heat exchanger 7 and the auxiliary heat exchanger 8 for mainly recovering latent heat are provided. Here, the water supply pipe 9 led into the appliance is connected to the water inlet side of the heat transfer pipe of the auxiliary heat exchanger 8 and the auxiliary heat exchanger 8 is arranged on the upstream side of the water flow of the main heat exchanger 7. The water discharge side of the heat transfer tube of the exchanger 8 is connected to the water input side of the heat transfer tube of the main heat exchanger 7, and the hot water discharge pipe 10 is connected to the water discharge side of the heat transfer tube of the main heat exchanger 7.

Further, the gas pipe 11 to the burner 6 is provided with a gas proportional valve 12 and a main electromagnetic valve 13A and a sub electromagnetic valve 13B, and the water supply pipe 9 is provided with a water amount sensor 14 and both are electrically connected to the controller 15. Has been. The controller 15 is also electrically connected to a motor for driving the air supply fan 4 and a temperature sensor 16 provided in the hot water discharge pipe 10.
On the other hand, a drain tray 17 for receiving the generated drain is provided below the auxiliary heat exchanger 8. The drain receiving tray 17 has a bottom portion inclined downward and forward, and the collected drain can be discharged out of a device from a drain discharge pipe (not shown).

An air supply passage 18 through which the air supply fan 4 introduces combustion air is formed outside the combustion chamber 3. The air supply passage 18 is formed in a cylindrical shape on the outer periphery of the exhaust passage 5 in the upper part of the combustion chamber 3 to form a double-pipe structure air supply / exhaust tube 20 with the exhaust passage 5 as the center.
The air supply / exhaust cylinder 20 is bent in an L shape so that the tip protrudes to the outside. By this, the exhaust of combustion exhaust from the exhaust passage 5 and the outside air (combustion air) from the air supply passage 18 are discharged. However, as shown in FIG. 2, the exhaust passage 5 and the air supply passage 18 are not completely separated from each other, and a part of the outside air in the air supply passage 18 is exhausted along the way. It is designed to be mixed with the combustion exhaust gas.

  That is, a pair of communication holes 21, 21 are formed in the exhaust passage 5 in the radial direction, and the exhaust passage 5 communicates with the air supply passage 18 through the communication holes 21, 21. However, in the normal supply / exhaust cylinder 20, the exhaust side has a positive pressure and the supply side has a negative pressure. Therefore, the external air is not introduced into the exhaust passage 5 when only the communication hole 21 is formed. Therefore, a venturi 22 is provided on the inner surface of the exhaust passage 5 on the upstream side of the communication holes 21 and 21 as an air introduction means that serves as a front throttle from the upstream toward the communication portion with the communication hole 21. In addition, a disc-shaped introduction portion 23 having a through hole 24 having the same diameter as the minimum diameter of the venturi 22 in the center is provided on the inner surface of the exhaust passage 5 on the downstream side of the communication holes 21 and 21.

  In the water heater 1 configured as described above, the controller 15 obtains a detection signal from the water amount sensor 14 when the hot water tap connected to the downstream side of the tap pipe 10 is opened and water is passed through the appliance body 2. The igniter (not shown) is operated, and the main solenoid valve 13A, the sub solenoid valve 13B, and the gas proportional valve 12 are opened to supply gas to the burner 6 to perform ignition control of the burner 6. After ignition of the burner 6, the controller 15 determines the degree of opening of the gas proportional valve 12 according to the difference between the hot water temperature detected by the temperature sensor 16 and the set temperature set by a remote controller (not shown) connected to the controller 15. Is controlled to continuously change the gas amount so that the tapping temperature matches the set temperature. Further, the ratio of the gas amount to the air amount is controlled by changing the rotational speed of the air supply fan 4 in accordance with the change in the gas amount.

  Due to the combustion of the burner 6, the combustion exhaust gas passes through the main heat exchanger 7 and the auxiliary heat exchanger 8 in order and is discharged from the exhaust passage 5. First, the high-temperature combustion exhaust gas is heat-exchanged by the main heat exchanger 7. The sensible heat is mainly recovered. Thereafter, the combustion exhaust gas passes through the auxiliary heat exchanger 8 and is subjected to heat exchange with water flowing through the auxiliary heat exchanger 8 at this time, whereby sensible heat that has not been recovered by the main heat exchanger 7 is recovered. At this time, if the temperature of the combustion exhaust gas becomes lower than the dew point, drain is generated, so that latent heat can also be recovered. The generated drain is received by the drain tray 17 and discharged to the sewer or the like through the drain discharge pipe.

  At this time, in the supply / exhaust cylinder 20, combustion air flows through the supply passage 18 as the supply fan 4 rotates (solid arrow in FIG. 2), and the combustion exhaust that has passed through the auxiliary heat exchanger 8 passes through the exhaust passage 5. It flows (dotted arrow in FIG. 2). Here, the combustion exhaust gas flowing through the exhaust passage 5 increases in speed when passing through the venturi 22 and flows downstream from between the communication holes 21 and 21 through the through hole 24 of the introduction portion 23. Due to the acceleration of the combustion exhaust gas, the internal pressure of the exhaust passage 5 in the vicinity of between the communication holes 21 and 21 becomes lower than the internal pressure of the air supply passage 18. , 21 is introduced into the exhaust passage 5 and is mixed with the combustion exhaust gas as it is and flows downstream. Therefore, the temperature of the combustion exhaust is lowered.

  As described above, according to the hot water heater 1 of the above-described form, the communication hole 21 communicating with the air supply passage 18 is formed in the exhaust passage 5, and the air supply passage is provided between the exhaust passage 5 and the air supply passage 18. 18 is provided with an air introduction means (venturi 22) for moving a part of the combustion air from the communication hole 21 to the exhaust passage 5, thereby lowering the temperature of the combustion exhaust by mixing the combustion air with the combustion exhaust. At the same time, the relative humidity of the combustion exhaust can be efficiently reduced. Therefore, even when the supply passage 18 and the exhaust passage 5 are adjacent to each other, the generation of drain in the exhaust passage 5 can be suitably prevented. Accordingly, the deterioration and corrosion due to drain can be suppressed, the life can be extended, and the prevention of white smoke can be expected.

In particular, here, the air introduction means makes the flow velocity of the combustion exhaust gas in the exhaust passage 5 faster than the flow velocity of the combustion air in the air supply passage 18, so that the flow velocity of the combustion air and the combustion exhaust gas is adjusted. Thus, the air introduction means can be easily formed.
In addition, the air introduction means is formed in the vicinity of the communication hole 21 of the exhaust passage 5 and is a venturi 22 that has a passage area that decreases from the upstream to the downstream of the flow of combustion exhaust gas, so that the air introduction means can be easily formed. be able to.

Further, since the communication hole 21 and the venturi 22 are provided in the air supply / exhaust cylinder 20 having a double pipe structure in which the air supply passage 18 is formed on the outer periphery of the exhaust passage 5, the exhaust passage 5 and the air supply passage 18 are adjacent to each other. The communication hole 21 and the venturi 22 can be easily provided using the air supply / exhaust tube 20.
In addition, the heat exchanger includes a main heat exchanger 7 that recovers sensible heat from the combustion exhaust of the burner 6, and a sub heat exchanger 8 that recovers latent heat from the combustion exhaust that has passed through the main heat exchanger 7. Since the combustion exhaust gas that has passed through the auxiliary heat exchanger 8 is discharged from the exhaust passage 5, the temperature of the combustion exhaust gas can be further lowered in the latent heat recovery type hot water heater 1 that originally has a low exhaust gas temperature. Therefore, synthetic resin can be used for the material of the air supply / exhaust cylinder 20 including the exhaust passage 5, leading to low cost.

Note that the number and shape of the communication holes, the shape of the venturi, and the like can be changed as appropriate. Moreover, in the said form, although the combination of the communicating hole and the venturi is provided in one place of the exhaust passage, it may be provided in a plurality of places to introduce the combustion air at each place.
Furthermore, here, the communication hole and the venturi are provided in the double-pipe structure supply / exhaust cylinder, but the present invention is not limited to this, and the present invention can be adopted as long as the exhaust passage and the supply passage are adjacent to each other. It is.

FIG. 3 shows an example. In this water heater 1A, the exhaust passage 5 and the air supply passage 18 are adjacent to each other in the appliance main body 2, and the exhaust passage 5 on the downstream side of the auxiliary heat exchanger 8 is connected to the hot water heater 1A. A communication hole 30 communicating with the air supply passage 18 is formed, and a venturi 31 is formed on the upstream side of the communication hole 30.
Therefore, in this case as well, the combustion exhaust gas flowing through the exhaust passage 5 is accelerated when passing through the venturi 31, and the internal pressure of the exhaust passage 5 becomes lower than the internal pressure of the air supply passage 18 due to the acceleration of the combustion exhaust gas. A part of the combustion air flowing through the air passage 18 is introduced into the exhaust passage 5 from the communication hole 30, and is mixed with the combustion exhaust gas as it is and flows downstream. Therefore, the temperature of the combustion exhaust is lowered.

  However, the venturi is not limited to the one provided on the upstream side of the communication hole. For example, as shown in FIG. 4, even when the venturi 22a protrudes downstream beyond the communication hole 21, It is possible to introduce air supply. This is the same even when the exhaust passage and the supply passage are provided adjacent to each other as described in FIG.

Of course, the air introduction means is not limited to the venturi. For example, the difference in internal pressure is set by providing a difference in passage area (exhaust passage is small and supply passage is large) between the exhaust passage and the supply passage communicated by the communication hole, and combustion air to the exhaust passage May be introduced.
Further, the air introduction means of the present invention is only required to have a force to draw the combustion air to the exhaust passage side by the intermolecular force between the combustion exhaust gas flowing through the communication hole and the combustion air. It is not limited to the setting of the difference in flow velocity and the difference in internal pressure. For example, in the case of a dual structure air supply / exhaust cylinder with the air supply passage on the outside and the exhaust passage on the inside, the air in the air supply passage is swirled by fins or the like to bring the air in the air supply passage into the exhaust passage. If it is configured to be pushed in, or if it is a dual structure air supply / exhaust cylinder with the air supply passage on the inside and the exhaust passage on the outside, the air in the air supply passage is swirled and the centrifugal force causes it to enter the exhaust passage It may be configured to guide. Furthermore, an adsorption force is applied by applying a charge to the fluid molecules in one of the adjacent exhaust passage and supply passage using a negative ion generator, etc., and energizing the suction plate provided in the other passage. To generate a magnetic field by using a coil or the like in the exhaust passage and the supply passage to magnetize fluid molecules and move a portion of the combustion air. It is also possible.

And in the said form, although this invention is applied to the latent heat recovery type water heater provided with the main heat exchanger and the sub heat exchanger, it is not restricted to this, The hot water supply provided only with one heat exchanger It can be a vessel.
In addition, the combustion appliance is not limited to the water heater, and the present invention can be applied to other appliances such as a gas fan heater as long as the exhaust passage and the supply passage are provided adjacent to each other.

  1, 1A ··· Hot water heater 2 · · Equipment body 3 · · Combustion chamber 4 · · Air supply fan 5 · · Exhaust passage, 6 · · Burner, 7 · · Main heat exchanger, · · · Sub Heat exchanger, 9 ... Water supply pipe, 10 ... Heating pipe, 15 ... Controller, 18 ... Air supply passage, 20 ... Air supply / exhaust cylinder, 21, 30 ... Communication hole, 22, 22a, 31 ... Venturi, 23..Introduction section, 24..Through hole.

Claims (5)

Inside the appliance body, a burner, a heat exchanger heated by the combustion exhaust of the burner, an exhaust passage for exhausting the combustion exhaust that has passed through the heat exchanger, and an air supply fan for supplying combustion air to the burner And an air supply passage provided adjacent to the exhaust passage and for introducing combustion air to the air supply fan,
A communication hole communicating with the air supply passage is formed in the exhaust passage, and a part of the combustion air in the air supply passage is passed through the communication hole between the exhaust passage and the air supply passage. A combustion appliance comprising an air introduction means for moving to an exhaust passage.   2. The combustion appliance according to claim 1, wherein the air introduction unit is configured to make a flow velocity of the combustion exhaust gas in the exhaust passage faster than a flow velocity of the combustion air in the supply air passage.   The combustion according to claim 2, wherein the air introduction means is a venturi that is provided in the vicinity of the communication hole of the exhaust passage and has a passage area that decreases from upstream to downstream of the flow of the combustion exhaust gas. Instruments.   The said communicating hole and an air introduction means are provided in the air supply / exhaust cylinder of the double pipe structure by which the said air supply path is formed in the outer periphery of the said exhaust path. Burning appliances.   The heat exchanger comprises a main heat exchanger that recovers sensible heat from the combustion exhaust of the burner, and a sub heat exchanger that recovers latent heat from the combustion exhaust that has passed through the main heat exchanger, and the sub heat exchange The combustion appliance according to any one of claims 1 to 4, wherein combustion exhaust gas that has passed through the vessel is discharged from the exhaust passage.

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