JP2732019B2 - Gas combustion equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas combustion device,
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas combustion device of the type in which water vapor in combustion exhaust gas from a gas burner is condensed, and the latent heat is absorbed by a heat exchange section to improve thermal efficiency.

[0002]

2. Description of the Related Art As shown in FIG. 4, there is a gas combustion apparatus of the above type in which a gas burner (3) and a two-stage heat exchanger (1) are combined. This heat exchanger
(1) is composed of a main heat exchange section (1a) and a sub heat exchange section (1b) disposed below the main heat exchange section (1a).
Is a water pipe (11) and a number of fins (12
a) (12a), and the other sub heat exchange portion (1b) is a portion of the water pipe (11) upstream of the main heat exchange portion (1a) and a number of fins (12b) provided on the outer periphery thereof. ) (12b).
A drain outlet (8) for discharging drain adhering to the heat exchanger (1) to the outside is provided below the heat exchanger (1).
Is provided.

The gas burner (3) is disposed sideways so that the main heat exchange section (1a) is located in the vicinity of the flame forming area. In this apparatus, when tap water is supplied from the upstream end of the water pipe (11) located on the side of the sub heat exchange section (1b) by burning the gas burner (3), the water flow in the water pipe (11) becomes: The heat generated by the gas burner (3) is absorbed from the fins (12a) (12b), etc., and is taken out as hot water from the main heat exchange section (1a). 3) The function of absorbing the sensible heat of the combustion exhaust is mainly due to the main heat exchange section (1a)
In the sub heat exchange section (1b), the action of mainly condensing water vapor in the combustion exhaust gas of the gas burner (3) and absorbing the latent heat thereof is performed. That is, in the sub heat exchange section (1b), sensible heat is deprived and the cooled combustion exhaust is cooled to a temperature equal to or lower than its dew point to generate drain, and the latent heat at that time is used as the sub heat exchange section (1b). In this case, heat is absorbed by the water flowing in the water pipe (11). The drain adhering to the sub heat exchange section (1b) drops by its own weight below the sub heat exchange section (1b) and is discharged to the outside from the drain discharge port (8). In this case, since the latent heat of the combustion exhaust is positively used, there is an advantage that thermal efficiency is improved.

[0004] However, in this case, the thermal efficiency cannot be sufficiently improved yet. The drain adhering to the sub heat exchange section (1b) is discharged to the water pipe (11) and fin (1
2b) (12b) is coated, whereby the drain film is interposed between the fins (12b) (12b) and the like and the combustion exhaust gas, so that the heat conductivity of the portion is reduced. On the other hand, the fin (12
b) Drain adhering to (12b) and the like moves to the lower end of the fins (12b) and (12b) by its own weight, and gradually grows in a water droplet form at the portion due to its surface tension. Then, when the water droplet grows to a predetermined size and its weight becomes larger than the adhesive force between the water droplet and the fins (12b) (12b), the water droplet finally drops downward. That is, in this case, the water droplets adhere to the fins (12b) and (12b) until they grow to a predetermined size and are not removed from the fins (12b) (12b).
It cannot be removed from 2b) (12b). For this reason, in the above-described conventional device, the drain film generated on the fins (12b) (12b) is not quickly removed from the fins (12b) (12b), and the heat efficiency is reduced accordingly.

[0005] As shown in FIG. 5, a main heat exchanging section (1a) is provided above the gas burner (3), and the main heat exchanging section (1a) is provided.
Even in the type in which the sub heat exchange section (1b) is disposed above (1a), if drain is generated in the sub heat exchange section (1b) by the above-described operation, the same disadvantages as described above will occur. Occurs. The present invention relates to such a “many fins on the outer periphery of the water pipe (11)”.
(12a) (12a) is provided to constitute a main heat exchange section (1a), and a large number of fins (12b) (12b) ) To constitute the sub heat exchange section (1b), and the main heat exchange section (1a) and the sub heat exchange section (1b) are sequentially arranged in this order downstream of the gas burner (3) in the exhaust passage. Thus, the former main heat exchange section (1a) absorbs the sensible heat of the combustion exhaust gas, and the latter sub heat exchange section (1b) cools the combustion exhaust gas coming into contact with it below the dew point and absorbs latent heat from the combustion exhaust gas. It is an object of the present invention to improve the thermal efficiency in the above-described gas combustion device.

[About the invention of claim 1]

[0007]

[Technical Means] The technical means of the present invention taken to solve the above-mentioned problem is described in "The water pipe (11) in the sub heat exchange section (1b)".
The hanging piece is attached to the lower end of the fin (12b) (12b)
(5) are connected or adjacent to each other.

[0008]

The above technical means of the present invention operates as follows. When this device is operated, the water flow in the water pipe (11) of the main heat exchange section (1a) and the sub heat exchange section (1b) reduces the amount of heat generated by the gas burner (3) as in the conventional example described above. While absorbing heat from the fins (12a) (12b) and the like, the fins in the sub heat exchange section (1b)
(12b) The drain generated in (12b) is finned by its own weight.
(12b) Move to the lower end of (12b).

Since the hanging piece (5) is continuously provided at or near the lower end of the fins (12b) (12b), the fins (12b) (12b)
The drain reaching the lower end of b) comes into contact with and wets the upper end of the hanging piece (5), and the drain is gradually or at a stretch depending on the conditions through the boundary between these two pieces. It spreads. That is, the same phenomenon that the drain generated on the surfaces of the fins (12b) and (12b) flows down to the surface continuously proceeds to the hanging piece (5) side through the boundary between these two, The above-mentioned drain flows down the above-mentioned boundary part and moves quickly to the hanging piece (5) side, and drops from the hanging piece (5), just as it does on the surface of the fins (12b) and (12b). It is.

[0010]

According to the present invention having the above-described configuration, the present invention has the following specific effects. The drain attached to the surface of the sub heat exchange section (1b) and causing a decrease in its thermal efficiency is a lower hanging piece (5).
Since it moves quickly, large water droplets with drain do not stop on the fins (12b) (12b) and this water droplet does not stop in a bridge shape between the fins (12b) (12b), which is different from the conventional one described above. Thermal efficiency is improved as compared to the above.

[Claim 2 and subsequent inventions] Claim 2
The technical means of the invention of claim 1 is that in the invention of claim 1 described above, "the hanging piece (5) is disposed so as to extend over a plurality or a large number of fins (12b) (12b)". ,fin
(12b) The drain that has reached the lower end of (12b) is quickly moved to the hanging piece (5) connected to or close to the lower surface of the fins (12b) (12b) by the above-described action. Thermal efficiency is improved as in the invention of Item 1. In particular, when the hanging piece (5) is arranged with a slight gap from the lower ends of the fins (12b) and (12b) as in the invention of claim 3, the drain is formed by the fins (12b).
When it grows to some extent at the lower end of the piece, it moves at a stroke to the hanging piece (5) side and flows downward due to its inertia, so that water drops hardly stop on the hanging piece (5). In these devices, since the hanging piece (5) is arranged so as to straddle a plurality of or many fins (12b) (12b), the flow of the combustion exhaust gas from the gas burner (3) is reduced by the hanging piece (5). 5) makes it less likely to be hindered, and makes it easier to process and manufacture the hanging piece (5).

[0012] Further, in the case of "the hanging piece (5) is a narrow tongue piece (5a) extended and protruded from the lower end of each fin (12b)",
The drain that has moved to the hanging piece (5) by the above-described action has the area of the fin (12b) because the hanging piece (5) is a narrow tongue piece (5a). Since it is smaller than (12b), the adhesive force of the drain to the tongue piece (5a) is also small. Therefore, in the tongue piece (5a), the size of the water droplet on which the drain can grow due to the surface tension becomes extremely small, whereby the dripping of the drain below the hanging piece (5) is further promoted.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. The embodiment shown in FIG. 1 has a heat exchanger (1) provided with a heat exchanger (1) having a function of condensing combustion exhaust and absorbing the latent heat.
The present invention is applied to an F (forced supply / exhaust) water heater. In this apparatus, a can body (6) having a heat exchanger (1) is provided at a lower part of a water heater main body, and a gas burner (3) is provided at an upper part of the can body (6 in FIG. And an air supply box (7) having an air supply chamber (42) at the upper part thereof, and a fan (4) provided at an upper part of the air supply box (7). Exhaust passage located downstream of heat exchanger (1)
(21) is provided so as to run up and down the water heater main body.

The heat exchanger (1) comprises a main heat exchange section (1a) and a sub heat exchange section (1b) disposed below the main heat exchange section (1a). Consists of a water pipe (11) provided with annular fins (12a) (12a), and the other sub heat exchange section (1b)
Consists of a water flow pipe (11) located upstream of the main heat exchange section (1a) in the water flow path and having annular fins (12b) (12b). And the water pipe (11) in the main heat exchange section (1a)
Is composed of three stages, each stage being arranged in a meandering manner in two horizontal rows or three rows, and the water pipe (1b) of the other sub heat exchange section (1b).
1) is a one-stage configuration arranged in a meandering manner in two horizontal rows. Further, a guide plate (15) that is curved downward and has an opening (16) in the center is provided below the water pipe (11),
Thereby, the combustion exhaust gas supplied to the heat exchanger (1) is caused to flow along the peripheral wall of the water pipe (11) so that heat exchange therewith is promoted. Then, the combustion exhaust gas is discharged downward through the open portion (16) of the guide plate (15). Furthermore, in the water pipe (11) in the sub heat exchange section (1b),
A plate-shaped hanging piece (5) is provided so as to be in contact with the lower end of the fins (12b) (12b).
The longitudinal direction (L) of (5) is set to coincide with the pipe direction, and the height direction (W) of the hanging piece (5) is set to coincide with the vertical direction of the water heater main body (FIG. 2). reference). in this way,
The reason why the hanging piece (5) is integrally formed in a single plate is from the viewpoint of not obstructing the flow of the combustion exhaust gas and the easiness of processing and manufacturing. In this embodiment, tap water is supplied from the end of the water pipe (11) on the side of the sub heat exchange section (1b), and hot water is taken out from the uppermost water pipe (11). The lower part of the can body (6) in which the heat exchanger (1) is housed is open, and the drain generated in the sub heat exchange part (1b) is discharged to the open part (16) of the guide plate (15). ), And is discharged outside through a drain outlet (8) below the can body (6).

The gas burner (3) is of an all-primary air combustion type, and comprises a mixing pipe (32) and a plurality of gas nozzles (31) facing the mixing pipe (32). The primary air is pushed and supplied by the fan (4). In this apparatus, in order to uniformly supply the primary air to the gas burner (3), the primary air is dispersed between the fan (4) and the gas burner (3). Board (45)
Is interposed.

The exhaust passage (21) has a configuration in which an exhaust port (2) formed in an upper part of the water heater and a lower part of the can (6) are connected to each other. Therefore, the primary air is supplied to the mixing pipe (32) by operating the fan (4), and the gas nozzles (31) (31)
When gas is supplied to the mixing pipe (32) to burn the gas burner (3) and supply tap water from the upstream end of the water pipe (11),
The water flow in the water pipe (11) of the main heat exchange section (1a) and the sub heat exchange section (1b) is controlled by the heat generated by the gas burner (3).
After being absorbed from the water flow pipe (11) in the upper stage, it becomes hot water and is taken out to the outside, and the combustion exhaust gas after passing through the heat exchanger (1) passes through the exhaust passage (21) to the exhaust port (2). Is discharged to the outside.
In this endothermic action, the action of absorbing the sensible heat of the combustion exhaust gas of the gas burner (3) is mainly performed in the main heat exchange section (1a), and in the sub heat exchange section (1b), Mainly gas burners
The function of (3) is to condense the combustion exhaust gas and absorb the latent heat. That is, in the sub heat exchange section (1b), the sensible heat is deprived and the cooled combustion exhaust is cooled below its dew point temperature to generate drain, and the latent heat at that time is converted into the sub heat exchange section (1b). ) Is absorbed by the water flowing in the water pipe (11). At this time, drain generated in the sub heat exchange section (1b) is generated by the above-described operation.
The hanging piece connected to the lower end of the fin (12b) (12b) in b)
(5) is quickly transmitted and dripped at the bottom of the water heater and discharged to the outside through the drain outlet (8).

The above embodiment can be modified as follows. . In the above embodiment, the hanging piece (5) is connected to each fin (12b) (12
b) Formed by a single rectangular plate that contacts the lower end of
(5) The fin (12b)
(12b) It is good also as a structure which provided the convex part in the arrangement | positioning part, and provided the recessed part in the non-arrangement part in this lower end, respectively. Also, fins (12b)
The hanging piece (5) may be provided independently for each.
In any of the above cases, the fins (12b) (12b) and the hanging pieces
A slight interval may be left between (5).

As shown in FIG. 3, each fin (12b) (12
A narrow tongue piece (5a) obtained by extending the lower end of b) may be adopted as the hanging piece (5), and the tongue piece (5a) may be provided for each fin (12b). In this case, if the adjacent tongue pieces (5a) are displaced, drains (water droplets) generated on each of the tongue pieces (5a) and (5a) will not be connected to the adjacent tongue pieces in a bridge shape. . In the above embodiment, the guide plate is used to promote heat exchange.
Although (15) is provided, this need not be provided. . In the above embodiment, the main / sub heat exchange sections (1a) (1b) are provided with a water pipe (11) and a fin (1
2a) and (12b), but a large number of fins composed of metal plates having a relatively large area are juxtaposed, and the meandering water pipe (1
The primary and secondary heat exchange sections (1a) (1)
b) may be formed. . In the above embodiment, the water pipe (11) is bent in a meandering shape so as to have a four-stage configuration, in which the lowest stage is the sub heat exchange unit (1b) and the other three stages are the main heat exchange unit. However, depending on the sensible heat absorption capacity of the main heat exchange section (1a), the sub heat exchange section (1b) that absorbs latent heat has a plurality of stages, such as two or three stages from the bottom. Also in such a case, the water pipes of each stage in the sub heat exchange section (1b)
Provide a hanging piece (5) on (11).

When the sub heat exchange section (1b) is constructed in a plurality of stages as described above, water may be supplied from the water pipe (11) at the second or third stage from the bottom. Also, including the case of the above embodiment, the hot water may be taken out from the second or third stage from the top. . In the above embodiment, the fan (4) is provided on the side of the air supply passage, but may be provided on the side of the exhaust passage (21). . In the above-described embodiment, the present invention is applied to the FF (forced supply / exhaust) type water heater, but in addition to the water heater, a gas combustion device such as a heater for circulating heated water, or The present invention can be applied to a gas combustion device such as a FE (Forced Exhaust) water heater or a heater of the above-described type. . Further, the present invention is not limited to a heat exchanger of the type mainly absorbing sensible heat in the main heat exchange section (1a) and mainly absorbing latent heat in the sub heat exchange section (1b), as well as the main heat exchange section (1a). ) Absorbs only sensible heat and the sub heat exchange section (1b) absorbs only latent heat.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of an embodiment of the present invention.

FIG. 2 is a sectional view taken along line XX.

FIG. 3 is an explanatory view of a tongue piece (5a).

FIG. 4 is an explanatory view of a conventional example.

FIG. 5 is an explanatory view of another conventional example.

[Explanation of symbols]

 (1a) ・ ・ ・ Main heat exchange part (1b) ・ ・ ・ Sub heat exchange part (11) ・ ・ ・ Water pipe (12a), (12b) ・ ・ ・ Fin (3) ・ ・ ・ Gas burner (5) ・..Dropping pieces (5a)

Claims (4)

(57) [Claims] A large number of fins (12a) are provided on the outer periphery of a water pipe (11).
(12a) to constitute the main heat exchange section (1a),
A number of fins (12b) (12b) are provided on the outer periphery of the upstream side of the main heat exchange section (1a) in (1) to form a sub heat exchange section (1b), and the downstream side of the gas burner (3) in the exhaust passage. The main heat exchange part (1a) and the sub heat exchange part (1b) are sequentially arranged in this order on the side, so that the former main heat exchange part (1a) absorbs the sensible heat of the combustion exhaust gas and the latter heat exchange part In the gas combustion device in which the combustion exhaust gas coming into contact with the combustion exhaust gas is cooled below the dew point so as to absorb latent heat from the combustion exhaust gas, the outer periphery of the water pipe (11) in the sub heat exchange unit (1b) A gas combustion device in which a hanging piece (5) is continuously provided at or near a lower end of the provided fins (12b) (12b). 2. The method according to claim 1, wherein the hanging piece is connected to a plurality of fins or a plurality of fins.
2. The gas combustion device according to claim 1, wherein the gas combustion device is disposed so as to extend between 2b and (12b). 3. The gas combustion apparatus according to claim 2, wherein the hanging pieces (5) are arranged with a slight gap from the lower ends of the fins (12b). 4. The gas combustion apparatus according to claim 1, wherein the hanging pieces (5) are narrow tongue pieces (5a) protruding from lower ends of the fins (12b).