JP2001336887A - Heat exchanger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To develop a heat exchanger capable of preventing a waste heat dissipating to an exterior, preventing a deformation of a body and preventing a dew formation to abort a corrosion of an inner water channel. SOLUTION: Shield members 50 are respectively provided between an inner piping 3 of a row of an upper stage (a) and an inner wall 40b of a body 2 and between inner piping 3 of a row of an upper stage (e) and an inner wall 40d of the body 2. Since these parts are blocked, a burnt gas does not flow to the vicinity of the wall 40bd. Thus, the wall 40bd is not heated, its deformation is not brought about and its heat is not wastefully externally dissipated. An end of an external water channel 6 is connected to the internal water channel 3 provided at an intermediate part, and water is first supplied to a second water channel from the end. Accordingly, even when a low temperature water passes through the piping 3 of the row of the upper stage (b), the dew is not formed, the corrosion of the piping is aborted, and its durability is high.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat exchanger used for a water heater or the like. The heat exchanger of the present invention,
It is suitable for a water heater using a liquid fuel such as kerosene.

2. Description of the Related Art A heat exchanger such as a home water heater or a bath has a built-in heat exchanger. Hereinafter, a conventional heat exchanger will be described. FIG. 7 is a sectional view showing the inside of a water heater using kerosene as fuel. FIG.
FIG. 8 is a cross-sectional view of a heat exchanger according to the related art, which is viewed from a direction AA in FIG. 7. FIG. 9 shows a conventional heat exchanger, and is a cross-sectional view of the heat exchanger as viewed from the direction BB of FIG.

A heat exchanger 101 built in a water heater 100
Is constituted by a body 2, a plurality of rows of internal water channels 3 and external water channels 6. That is, the body 2 is made of a thin plate such as a copper plate, a steel plate, a tin-plated iron plate, and stainless steel, and is a rectangular cylinder having a rectangular cross section surrounded by the inner walls 40a, b, c, and d. Flanges 4 for joining with other members are provided at upper and lower opening ends of the body portion 2.

The internal water passage 3 traverses the body 2 in the vertical direction, and the inner water passage 3 is opposed from one inner wall 40a to the other inner wall 40c.
Is provided across. In the examples shown in FIGS. 8 and 9, the internal water passages 3 are provided in five rows and two stages at a position near the lower end of the body 2. The internal waterway 3 is connected to the ends of adjacent waterways outside the body 2, and all the internal waterways 3
Are connected in series to form a single channel. The heat exchange between the combustion gas and the water is mainly performed by the internal water passage 3. Therefore, the internal waterway 3 is formed of a metal tube having excellent thermal conductivity, such as copper, and a number of fins 5 are provided outside the internal waterway 3 to improve the efficiency of heat exchange. The configuration of the internal water channel 3 and the configuration of the fins 5 are well known.

On the other hand, an outer channel 6 is wound around the outer periphery of the body 2. The outer channel 6 is wound around a portion from the upper end of the body 2 to the vicinity of the inner channel 3, and is brazed to the outer peripheral surface of the body 2. The external water channel 6 is also made of a copper pipe. The main purpose of the outer water passage 6 is to cool the body 2 to prevent deformation, but the end of the outer water passage 6 is connected to the inner water passage 3 to improve thermal efficiency. That is, in this type of heat exchanger 101, the external water channel 6 wound around the body 2 functions as a water supply channel for supplying water to the internal water channel 3.

For this reason, in the heat exchanger 101 of the prior art, the end of the outer water passage 6 as a water supply passage is connected to the inner water passage 3 located at the most end so that the pipe layout is properly arranged.
Was connected to. For ease of understanding, FIGS.
In the heat exchanger 101 of the prior art, the end of the outer water channel 6 is located at the end of the inner water channel 3 in the closest upper row a as shown in FIG. Inner wall 4
It was connected to the end on the 0b side. The other end of the internal waterway 3 in the upper row a is connected to the internal waterway 3 in the adjacent upper row b outside the body 2, and the other end is sequentially connected to the adjacent internal waterway 3 to form the internal waterway 3. All constituted a single channel.

In the water heater 100 using liquid fuel such as kerosene as a fuel, a fuel spray burner 11 is attached to an upper end of a heat exchanger 101 and a flue gas passage 12 is attached to a lower end as shown in FIG. . Fuel spray type burner 1 shown in FIG.
Numeral 1 is a type called a reverse combustion type, which injects a flame downward. Fuel spray burner 1 shown
Reference numeral 1 denotes a variable burner type gun type burner using a two-stage combustion cylinder, and the airflow in the burner is substantially downward.

The structure of the fuel spray type burner 11 will be briefly described.
Open-ended nozzle storage tube 32 having a built-in nozzle and open-ended combustion tube 3 connected to the open end of the nozzle storage tube 32
3 is provided. The combustion cylinder 33 includes a first combustion cylinder 34 connected to the open end of the nozzle housing cylinder 32 and the first combustion cylinder 34.
And a second combustion cylinder 35 having a larger diameter. The first combustion cylinder 34 and the second combustion cylinder 35 are provided with a large number of air introduction ports 41. Further, a fuel diffusion plate 36 is attached downstream of the fuel spray burner 11. The fuel diffusion plate 36 is a member for promoting fuel agitation, and has a substantially rod shape.

In the prior art, the flame generated by the fuel spray burner 11 spreads in the body 2 of the heat exchanger 101, and hot combustion gas passes through the body 2. Then, the combustion gas comes into contact with the internal water passage 3, and heat exchange is performed.

[0010]

As described above, in this type of heat exchanger 101, the flame spreads in the body 2 and the combustion gas passes through the body 2. More specifically, the combustion gas is “between the inner wall 40b of the body 2 and the inner water passage 3 in row a”, “between the inner water passage 3 in row a and row b”, and “b row c
Between rows of internal waterways 3 "" Between rows of internal waterways 3 in row c and row d "
It passes through "between the internal waterway 3 in row e and the inner wall 40d of the body 2". Here, when looking at each passage of the combustion gas, both sides of the intermediate portion are the internal water passages 3, whereas one of the end passages is the inner wall 40 of the body portion 2 as described above.

As a result, the combustion gas flowing through the passage at the end has a lower rate of heat exchange with water than the center, and the heat is wasted to the outside through the inner wall 40 of the body 2. Further, there is a concern that the combustion gas flowing through the portion may heat the inner wall of the body portion 2 and deform the body portion 2. In particular, as shown in FIG. 7, when a burner 11 having a fuel diffusion plate 36 is used, the flame tends to spread horizontally. There is a high tendency that the inner wall 40 of the body 2 is heated to release the heat.

Therefore, the present invention focuses on the above-mentioned problems of the prior art, and aims to develop a heat exchanger capable of preventing unnecessary heat dissipation to the outside and preventing deformation of the body 2. Things. In addition, the present invention solves the problem of dew condensation newly found during the development.

[0013]

Means for Solving the Problems In order to solve the above-mentioned problems, the present inventors have intensively studied and, using a shielding member, the inner wall 40 of the body 2 and the inner water passages 3 in rows a and b.
We came up with a configuration to block the space, and made a prototype. In this prototype, the temperature of the body 2 is not excessively increased, and the deformation of the body 2 is unlikely to occur. Also, since heat dissipation from the body 2 was small, the heat efficiency was high. However, when the present inventors conducted a durability test of the prototype, corrosion was found in a limited portion of the internal waterway 3 where the combustion gas was shielded. More specifically, corrosion occurred only at the portion on the inner wall 40b side of the internal waterway 3 in the upper row a.

When the cause was further pursued, the upper stage a
Condensation occurred in the internal water passages 3 of the row, and the dew condensation corroded the internal water passages 3. In addition, when the cause of dew condensation in the part concerned was examined, the temperature of the inner part waterway 3 itself was low because the inner passage 3 in the upper row a was a portion through which water first passed, and the shielding member caused combustion to the part. This is because the temperature of the atmosphere in this part is extremely low as compared with others because the gas flow is restricted. Therefore, the present inventors changed the piping system and introduced water from a middle portion of the body 2 into a series of flow paths constituted by the internal water passages 3. That is, since the middle portion of the body 2 was close to the center of the flame, the ambient temperature was high, and it was considered that dew condensation would not occur.
The prototype whose pipe was changed in this way worked as expected, and the problem of corrosion of the internal waterway 3 was solved.

According to a first aspect of the present invention, which has been completed by the above-described series of researches, a body portion through which a high-temperature gas passes, and a plurality of rows of internal flow paths crossing the body portion are provided.
In a heat exchanger in which an object to be heated flows sequentially through the internal flow path and is discharged, the object to be heated first passes through an internal flow path located in the middle, and is introduced into another internal flow path. It is a heat exchanger. Here, the “middle internal flow path” refers to an intermediate flow path excluding flow paths located at both ends of a plurality of flow paths of the object to be heated flowing through the heat exchanger (body portion).

According to a second aspect of the present invention, there is provided a body portion through which a high-temperature gas passes, and a plurality of rows of internal flow paths crossing the body portion, and a heated object flows through the internal flow path and is discharged. In the heat exchanger, a shielding member is provided inside the body portion, and the shielding member restricts the flow of high-temperature gas between the internal flow path located at the end and the wall surface of the body portion. It is a heat exchanger.

Further, the invention according to claim 3 has a body portion through which a high-temperature gas passes, an external flow path is wound around the body portion, and a plurality of rows of internal flow passages are provided inside the body portion. In a heat exchanger in which a passage is provided and an external flow passage wound around the body portion is connected to an internal flow passage provided inside the body portion, the heat exchanger sequentially flows through the internal flow passage and is discharged. The external flow path wound around the part is connected to the internal flow path provided in the middle of the body, and the object to be heated first passes through the internal flow path provided in the middle, and A heat exchanger introduced into a flow path.

According to a fourth aspect of the present invention, which is obtained by further improving the above-described aspect, a burner is attached to the body portion.
A heat insulating material is provided on a part of a part of the inner surface of the body part from the internal flow path between the burner mounting part and the internal flow path and within two-thirds of a distance between the two. A heat exchanger according to any one of claims 1 to 3.

In the heat exchanger according to the present invention, a heat insulating material is provided at a part of a portion between the burner mounting portion on the inner surface of the body portion and the internal flow path and closer to the internal flow path than the center between them. .
In the heat exchanger of the present invention, a heat insulating material is arranged at a minimum necessary portion. That is, since the spread of the flame is small at the mounting portion of the burner and the temperature rise of the inner wall of the body is small, it is not always necessary to protect with a heat insulating material. On the other hand, the part on the side of the internal flow path has a large flame spread and a high temperature on the peripheral side, and thus it is highly necessary to protect it with a heat insulating material.

The invention according to claim 5 is characterized in that a spray type burner is attached to the body, and the spray type burner supplies hot combustion gas to the center of the body. The heat exchanger according to any one of claims 1 to 4.

In the heat exchanger of the present invention, a spray burner is attached to the body to heat the internal flow passage. Then, the spray burner supplies hot combustion gas to the central portion of the body. Therefore, in the heat exchanger according to the first, third or fourth aspect, the portion through which water first passes is heated more strongly, and dew condensation is prevented. In the heat exchanger according to the second, third, and fourth aspects, the temperature of the wall surface of the body is prevented from rising due to the function of the shielding member.

[0022]

Embodiments of the present invention will be described below. FIG. 1 is a perspective view of a heat exchanger according to an embodiment of the present invention. FIG. 2 is a cross-sectional view taken along the line AA of FIG. FIG. 3 is a cross-sectional view taken along the plane BB of FIG. FIG. 4 is a front view of the heat exchanger of FIG. FIG.
FIG. 2 is a side view of the heat exchanger of FIG. FIG. 6 is a cross-sectional view of a heat exchanger according to another embodiment of the present invention.

In each of the figures, reference numeral 1 denotes a heat exchanger according to an embodiment of the present invention. The heat exchanger 1 of the present invention is different from the prior art in that a shielding member 50 is provided inside and a piping path is different, and other configurations are the same as the conventional technology. Therefore, the description of the embodiment focuses on the shielding member 50 and the piping path,
Other configurations will be described only briefly.

In the heat exchanger 1 of the present embodiment, a shielding member 50 is provided inside the body 2. Shielding member 50
Is a kind of packing, and a material having high heat resistance is selected. Specifically, the shielding member 50 is made of a ceramic fiber in an amorphous chamber obtained by melting alumina or silica at a high temperature and fibrillating with a high-speed gas flow, or a polycrystalline mullite ceramic fiber manufactured by a sol-gel technique. It is suitable as. The shielding member 50 may be formed in a predetermined shape in advance, or may be a clay-like member packed in a predetermined position. In the present embodiment, the shielding member 50 employs a configuration in which clay-like materials are packed.

The positions where the shielding members 50 are provided are two places (two rows), and one place is between the internal pipes 3 in the upper row a and the inner wall 40b of the body 2. Another one is upper e
A shielding member 50 is provided between the inner pipes 3 in the row and the inner wall 40 d of the body 2. The shielding member 50 is provided over the entire area in the width direction of the body 2.

Further, as another characteristic of the heat exchanger 1 of the present embodiment, the end of the external water passage 6 is connected to the internal water passage 3 provided at an intermediate portion. More specifically, in the present embodiment, the end of the outer channel 6 is connected to the inner channel 3 in the upper row b as shown in FIGS. 1 and 2, and the inner channel is firstly connected to the second channel from the end. Water is supplied to The other end of the internal waterway 3 in the upper row b is connected to an adjacent waterway in the upper row a. Further, the other end of the upper row a (returning to the water inlet side) is connected to the inner water path of the upper row c by skipping one internal water channel 3 (the upper row b). Thereafter, the upper row c to the upper row d
Row, upper row e row, lower row e row, lower row d row, lower row c row, lower row b
The rows are connected in the order of the lower row a, and the pipe is connected to the outside from the lower row a.

The heat exchanger 1 of the present embodiment is built in a water heater 100 as shown in FIG. 7 similarly to the prior art, and a fuel spray burner 11 is attached to an upper end of the heat exchanger 1 and a lower end thereof. A smoke exhaust path 12 is installed. Then, the flame generated by the fuel spray burner 11 spreads in the body 2 of the heat exchanger 1, and high-temperature combustion gas passes through the body 2. However, in the heat exchanger 1 of the present embodiment, the internal piping 3 in the upper row a
A shielding member 50 is provided between the inner wall 40b of the body portion 2 and between the inner pipes 3 in the upper row e and the inner wall 40d of the body portion 2, and these portions are closed. No combustion gas flows near 40 bd. Therefore, the inner wall 40bd is not heated, and the deformation is prevented. In addition, heat is not dissipated to the outside.

In the heat exchanger 1 of the present embodiment, the external piping 6
Water is supplied from an elbow 51 (FIG. 1) provided at the upper end of the container. Then, the water flows through the outer pipe 6 wound around the outer periphery of the body 2, and first enters the inner pipe 3 in the upper row b from the end of the outer pipe 6. Here, the internal pipes 3 in the upper row b are located in the middle of the internal pipes 3 arranged in five rows, and the fuel spray burner 1
From 1 the hot combustion gases flow directly. In addition, there is no obstacle that obstructs the passage of the combustion gas at the site. Therefore, the ambient temperature is high near the internal piping 3 in the upper row b. Therefore, even if the low-temperature water passes through the internal piping 3 in the upper row b, no dew condensation occurs. Therefore, there is no pipe corrosion, and the durability is high. The water supplied from the internal pipes 3 in the upper row b passes through the internal pipes 3 in the upper row b, and then enters the internal pipes 3 in the upper row a.
At the time of entry, since the temperature of the water has already been raised to a considerable temperature, dew condensation does not occur in the internal piping 3 in the upper row a. The water flowing through the internal piping 3 in the upper row a is sequentially c.
Flow through the rows, d, and e, and go down to the lower row, e, d, and c
It passes through the rows, b and a, and is discharged outside.

In the embodiment described above, the shielding member 50
Illustrated an example in which a clay-like material was packed in a gap between the internal waterway 3 and the inner wall 40, but the heat exchanger 5 shown in FIG.
The same effect can be expected even if an eave-shaped shielding member 53 is provided on the upstream side between the inner waterway 3 and the inner wall 40 as in 2. In the heat exchanger 52 shown in FIG. 6, a heat insulating material 55 is provided on the inner wall of the body 2 to further suppress the deformation of the body 2. The heat insulating material 55 may be provided on the entire inner wall of the body portion 2. However, when the fuel spray type burner 11 is used, the flame does not reach the vicinity of the burner mounting portion, so that it is not necessary to mount the heat spraying burner. Specifically, the distance from the burner attachment portion to the internal pipe 3 is L, and it is not necessary to attach the heat insulating material 55 to a portion within L / 3 from the burner attachment portion. Also on the downstream side of the shielding member 53, the necessity of attaching the heat insulating material 55 is low because the amount of passage of the combustion gas is low. From such a viewpoint, in the heat exchanger 52 shown in FIG. 6, the distance from the burner mounting portion to the internal pipe 3 on the inner wall of the body 2 is L, and the internal pipe 3 is smaller than 2L / 3.
A heat insulating material 55 is provided on the side and up to the shielding member 53.

In each of the above-described embodiments, two
The end of the outer channel 6 was connected to the second inner channel 3. The above-described embodiment has the most recommended piping layout and recommended configuration. However, in the present invention, the intermediate part (middle)
It suffices that water (the object to be heated) is first passed through the internal water channel 3 provided in the internal water channel 3. For example, the end of the external water channel 6 may be connected to the internal water channel 3 in row c or row d. It is also conceivable that water is first passed through the internal water channel 3 provided at the lower (downstream) intermediate portion. The heat exchangers 1 and 52 described above
Provided the internal waterway 3 in the lower part of the body part 2,
This is based on the premise that the burner 11 is attached to the upper portion, and the present invention is not limited to this configuration. Although the present invention has been developed as a heat exchanger used for a water heater, the technical idea of the present invention can be applied to a heat exchanger for heating other objects to be heated.

[0031]

As described above, according to the heat exchangers of the first and third aspects, the object to be heated first passes through the internal flow path located in the middle, and is introduced into the other internal flow paths. Therefore, there is an effect that dew condensation does not occur, piping corrosion is prevented, and durability is high.

In the heat exchanger according to the second and third aspects,
The shielding member restricts the flow of high-temperature gas between the internal flow path located at the end and the wall of the body, so that the temperature of the body is prevented from rising, and the body is deformed and waste heat is dissipated. The effect is prevented. That is, in the heat exchanger according to the second and third aspects, the flow of the high-temperature gas between the walls of the internal flow path located at the end is restricted by the heat shielding member, so that the temperature rise of the body portion is suppressed. This has the effect of preventing deformation of the body portion and unnecessary heat dissipation. together,
The high-temperature gas that has flowed to the end by the heat shielding member flows into the middle of the heat exchanger, and the temperature rise in the middle of the heat exchanger is promoted. Since the object to be heated is flowed first, the temperature of the part does not become low during combustion, and as a result, the temperature of the entire heat exchanger is made uniform, and the state where a part of the heat exchanger becomes low temperature is eliminated. This has the effect of making it difficult to generate a drain or the like.

Further, in the heat exchanger according to the fourth aspect, since a heat insulating material is attached only to a necessary portion, there is no waste of material.

The heat exchanger according to the fifth aspect is combined with a spray burner for supplying a high-temperature combustion gas to the central portion of the body portion, and has an effect of synergistically improving the operation and effect of the invention.

[Brief description of the drawings]

FIG. 1 is a perspective view of a heat exchanger according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view taken along the line AA of FIG.

FIG. 3 is a sectional view taken along a plane BB in FIG. 1;

FIG. 4 is a front view of the heat exchanger of FIG.

FIG. 5 is a side view of the heat exchanger of FIG. 1;

FIG. 6 is a cross-sectional view of a heat exchanger according to another embodiment of the present invention.

FIG. 7 is a sectional view showing the inside of a water heater using kerosene as fuel.

FIG. 8 is a cross-sectional view of a heat exchanger according to the related art, as viewed from a direction AA in FIG. 7;

FIG. 9 is a cross-sectional view of the heat exchanger according to the related art, as viewed from the direction BB of FIG. 7;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1,52 Heat exchanger 2 Body part 3 Internal waterway 6 External waterway 40abcd Inner wall 50,53 Shielding member 55 Insulation material 100 Water heater 101 Heat exchanger

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Ryoji Hasegawa 93 Edocho, Chuo-ku, Kobe, Hyogo Pref. (72) Inventor Hirofumi Tanaka 93F, Edo-cho, Chuo-ku, Kobe-shi, Hyogo F-term in Noritz Corporation (Reference) 3L036 AA04 AE03 3L103 AA08 AA12 AA32 BB43 CC02 CC27 DD05

Claims (5)

[Claims] 1. A heat exchanger in which a body portion through which a high-temperature gas passes and a plurality of rows of internal flow paths crossing the body portion are provided, and a heated object sequentially flows through the internal flow paths and is discharged. A heat exchanger, wherein an object to be heated first passes through an intermediate flow path located in the middle, and is introduced into another internal flow path. 2. A heat exchanger in which a body portion through which a high-temperature gas passes and a plurality of rows of internal flow paths crossing the body portion are provided, and an object to be heated is discharged through the internal flow path. A heat exchanger, wherein a shielding member is provided inside the unit, and the shielding member restricts the flow of high-temperature gas between the internal flow path located at the end and the wall surface of the body. 3. A body having a body through which a high-temperature gas passes, wherein an external flow path is wound around the body, and a plurality of rows of internal flow paths are provided inside the body. The external flow path wound around the body is connected to the internal flow path provided inside the body part, and is wound around the body part in the heat exchanger which is sequentially discharged through the internal flow path and discharged. The external flow path is connected to the internal flow path provided in the middle of the body, and the object to be heated first passes through the internal flow path provided in the middle, and is introduced into another internal flow path. Characterized heat exchanger. 4. A body is provided with a burner, and a portion of the inner surface of the body near the internal flow path between the burner mounting portion and the internal flow path, which is within two-thirds of the distance therebetween. The heat exchanger according to any one of claims 1 to 3, wherein a heat insulating material is provided in a part of the heat exchanger. 5. A spray burner is attached to the body,
2. The spray-type burner according to claim 1, wherein a high-temperature combustion gas is supplied to a central portion of the body portion.
A heat exchanger according to any one of claims 1 to 4.