JPH07253281A - Heat exchanger - Google Patents

Abstract

PURPOSE:To reduce the size and weight of a heat exchanger having a heat exchanging unit and a combustion chamber drum while obtaining corrosion resistance against ammonia. CONSTITUTION:A heat exchanging unit 16 is formed of a heat transfer tube 13 made of an iron material such as stainless steel, etc., and a high thermal conductive material such as light alloy, copper, etc., and a dry combustion chamber drum 18 covering a combustion chamber 21 is formed of a heat insulator 19 and a combustion chamber drum cover 20. Thus, corrosion resistance against ammonia is obtained while reducing in size the unit 16. The drum 18 is disposed near a burning surface of a burner 22 to reduce in size the drum, thereby decreasing the size and weight of a heat exchanger.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat exchanger for heating a corrosive fluid such as ammonia used as a refrigerant of an absorption heat pump device with a burner.

[0002]

2. Description of the Related Art Generally, an example in which a non-corrosive fluid such as water is put into practical use in a water heater as a heat exchanger for heating with a burner has a structure as shown in FIG.

In the figure, 1 is a heat transfer tube, 2 is a heat transfer fin, 3 is a heat exchange drum which covers the outer circumference of a heat exchange section 4 constituted by the heat transfer tube 1 and the heat transfer fin 2, and 5 is a terminal of the heat transfer tube. U to connect
Bend 6 is a combustion chamber drum that covers combustion chamber 8 between heat exchange section 4 and burner 7, and 9 is a water pipe that surrounds the outer periphery of combustion chamber drum 6 and is in close contact with it. The material for the parts was made of copper.

The combustion chamber drum 6 is called a water pipe type combustion chamber drum cooled by a water pipe 9 and is usually constructed integrally with the heat exchange drum 3. Also, 10 is a fan, 1
1 is a fuel pipe.

[0005]

However, in the above-mentioned conventional example, although there is an advantage that it is small and lightweight among various heat exchanger types, in order to heat a corrosive fluid such as ammonia, a piping material is required. Since it cannot be used as it is because of the corrosion resistance of copper, it was necessary to use a highly corrosion-resistant iron-based material such as stainless steel for the heat transfer tube, the U-bend, and the like. However, since the stainless steel pipe has a higher strength than the copper pipe, the bending workability is poor, and when the water pipe type combustion chamber drum type combustion chamber drum similar to the conventional example is used, the combustion chamber drum becomes large. There was a flaw. That is, as shown in FIG. 8, the combustion surface of the burner 7 is usually a substantially quadrangular shape, but the water tube type combustion chamber drum 6 containing it is a quadrangular shape having arcs corresponding to the curvature of the bending of the water tube. There is. Here, when the water pipe is a stainless pipe, there is a drawback that the combustion chamber drum becomes large because the arc radius of the corner becomes large as shown by a broken line in the figure.

On the other hand, the heat exchanging drum 3 also has a drawback that the material is annealed due to the high temperature during the brazing process, the strength thereof is lowered, and the heat exchanging drum 3 is deformed by the load received during transportation. That is, in order to perform the brazing connection process between the heat transfer tube 1 and the U-bend 5, a nickel-based brazing material is used to secure the corrosion resistance to ammonia, but the brazing processing temperature is about 800 ° C. for the conventional copper-based brazing material. However, the temperature was as high as about 1000 ° C., and there was a drawback that the strength of the heat exchange drum 3 made of copper was significantly reduced.

The present invention solves the above-mentioned drawbacks and provides a compact and lightweight heat exchanger that retains the compactness of a conventional heat exchange portion while ensuring corrosion resistance to ammonia, and that includes a combustion chamber drum. Is the first purpose.

The second object is to obtain a durable and highly reliable heat exchanger while ensuring corrosion resistance to ammonia.

A third object is to reduce the temperature of the combustion chamber drum and obtain a more safe heat exchanger.

The fourth and sixth objects are to lower the temperature of the heat exchange drum and obtain a more safe heat exchanger.

[0011]

In order to achieve the above first object, the present invention provides a heat transfer tube having a heat exchange part made of an iron material such as stainless steel, and a light alloy which is penetrated and fixed to the heat transfer tube. Alternatively, the dry combustion chamber drum includes a plurality of heat transfer fins made of a highly heat-conductive material such as copper, and the heat insulating structure is arranged so that the combustion chamber drum covers the combustion chamber.

In order to achieve the second object, the present invention provides
An iron-based material such as stainless steel is used for the heat exchange drum arranged outside the heat exchange section.

In order to achieve the third object, the present invention provides
The combustion chamber drum has a double structure including a heat insulating material that covers the combustion chamber and a cooling air passage that covers an outer peripheral portion of the heat insulating material.

In order to achieve the fourth object, the present invention provides
A heat shield plate for exhaust gas from the burner is provided between the heat transfer fins and the heat exchange drum in the vicinity of the heat exchange drum.

In order to achieve the fifth object, the present invention provides
A heat insulating material is arranged inside the heat exchange drum.

In order to achieve the sixth object, the present invention provides
An exhaust gas guide is provided on the inner circumference of the heat exchange drum so that the exhaust gas is directed inward.

[0017]

With the above structure, the present invention makes it possible to secure the corrosion resistance to ammonia while maintaining the compactness of the conventional heat exchange section, and to dispose the combustion chamber drum in the vicinity of the combustion surface of the burner. Can be a combustion chamber drum.

Further, while ensuring corrosion resistance to ammonia, sufficient strength of the heat exchange drum is maintained even at high temperatures during brazing of the heat transfer tube and the heat transfer fin.

Further, since the combustion chamber drum has a double structure composed of a heat insulating material and a cooling air passage surrounding the outer peripheral portion of the heat insulating material, the temperature of the combustion chamber drum can be lowered.

Further, the heat shield plate prevents the high temperature exhaust gas from coming into strong contact with the heat exchange drum, thereby lowering the temperature of the heat exchange drum.

Further, the heat insulating material inside the heat exchanging drum prevents the exhaust gas from directly contacting the heat exchanging drum, thereby lowering the temperature of the heat exchanging drum.

Furthermore, since the exhaust gas flows inward by the exhaust gas guide on the inner circumference of the heat exchange drum, the temperature of the heat exchange drum decreases.

[0023]

Embodiments of the present invention will be described below with reference to the drawings.

In FIG. 1 and FIG. 2, 13 is a plurality of heat transfer tubes having a relatively thin wall, 14 is a plurality of thin heat transfer fins that are penetrated and fixed to the heat transfer tube 13, and 15 is a heat exchange section 16 inside.
The heat exchange drum, 17 is a connecting pipe for connecting the ends of the heat transfer pipes 13, 18 is the heat insulating material 19, and the combustion chamber drum cover 2
0 is a dry combustion chamber drum, 21 is a combustion chamber,
Reference numeral 22 is a burner for heating, 23 is a fan for supplying primary air and secondary air, 24 is a fuel pipe, 25 is an inlet pipe for the ammonia fluid to be heated, and 26 is this outlet pipe.

Here, the heat transfer pipe 13 and the connection pipe 17 are made of an iron-based material such as stainless steel, and have a corrosion resistance in the pipeline against a corrosive fluid such as ammonia which is a working medium of the absorption heat pump device. Has been secured. Further, the heat transfer fins 14 are made of a highly heat conductive material such as copper or aluminum, and promote heat transfer from the combustion gas to the heat transfer tubes 20 to form a compact heat exchange section 16 similar to the conventional one. There is. Further, the connection pipe 17 and the inlet pipe 25 / outlet pipe 26 are connected / fixed to the heat transfer pipe 13 by brazing using a nickel-based brazing filler metal, which ensures airtightness and connection while ensuring corrosion resistance to ammonia. The certainty is secured.

On the other hand, the dry combustion chamber drum 18 is placed near the combustion surface 27 of the burner 22 as shown in FIG.
Since the combustion chamber drum cover 20 is provided,
It is possible to make a small combustion chamber drum which cannot be obtained by the conventional water pipe type combustion chamber drum type. As a result, it is possible to reduce the size and weight of the heat exchanger including the heat exchange section and the combustion chamber drum while ensuring the corrosion resistance to a corrosive fluid such as ammonia.

Furthermore, the heat exchange drum 15 is made of an iron-based material such as stainless steel, and its strength is not significantly deteriorated even at high temperatures during brazing, and the load received during transportation or the like. Since it has sufficient strength, it does not deform, and a more reliable heat exchanger can be obtained.

Next, another embodiment of the present invention will be described with reference to FIG. The same parts as those in the above-mentioned embodiment are designated by the same reference numerals and the description thereof is omitted. 3 is different from the above embodiment in that the combustion chamber drum has a double structure of the heat insulating material 19 and the cooling air passage 27 provided outside thereof. 28 is a heat insulating material cover, 29 is an air passage cover,
The lower end of the cooling air passage 27 communicates with the air chamber 30 in which the fan 23 is open, and the upper end of the cooling air passage 27 opens near the heat exchange drum 15.

In this structure, a part of the air supplied from the fan 23 flows into the cooling air passage 27, cools the heat insulating material cover 28 and the air passage cover 29, and flows out to the vicinity of the heat exchange drum 15. As a result, the temperature of the air passage cover 29, which is located on the outermost side of the combustion chamber drum, is lowered, and burns are less likely to occur even if it is accidentally touched, and safety is improved.

Further, the air flowing out in the vicinity of the heat exchange drum 15 acts like an air curtain against the high temperature exhaust gas from the burner 22 and can also lower the temperature of the heat exchange drum 15.

In the embodiment shown in FIG. 4, in addition to the embodiment shown in FIG. 1, between the heat transfer fins 14 and the heat exchange drum 15,
A heat shield plate 31 made of a high heat conductive material is penetrated and fixed to the heat transfer tube 13 similarly to the heat transfer fins 14, and the heat exchange drum 15 is used.
It is arranged close to.

As a result, the high temperature combustion exhaust gas flowing from the combustion chamber 21 is less likely to come into contact with the heat exchange drum 15,
The temperature of the heat exchange drum 15 can be lowered, and overheating, discoloration, and deformation of the stainless steel heat exchange drum 15 can be prevented, and safety is improved.

Further, since the heat shield plate 31 is made of a highly heat conductive material, the heat of the combustion exhaust gas is transferred to the heat transfer tube 13 similarly to the heat transfer fins 14, so that the heat efficiency of the heat exchange section 16 is improved. .

In the embodiment shown in FIG. 5, the heat exchanger drum 15 of the embodiment shown in FIG. 1 is also provided with a heat insulating material 32 on the inner peripheral surface of the heat exchanger drum 15. Is prevented, and the heat exchange drum 15 is cooled to prevent discoloration / deformation and improve safety.

In the embodiment shown in FIG. 6, an exhaust gas guide 33 is provided on the inner periphery of the heat exchange drum so that the exhaust gas is directed inward (toward the center of the heat exchange part 16) at the exhaust gas inflow part to the heat exchange part 16. The exhaust gas does not come into strong contact with the heat exchanging drum 15 due to the provision of the heat exchanging drum 1.
It is possible to prevent discoloration / deformation due to low temperature of 5 and improve safety.

[0036]

According to the present invention, the heat exchange section is composed of a heat transfer tube made of an iron-based material such as stainless steel and heat transfer fins made of a high heat conductive material such as light alloy or copper. Since it is a dry-type combustion chamber drum using a heat insulating structure, a small heat exchange part can be obtained while ensuring corrosion resistance to corrosive fluid such as ammonia, and it is not possible with the conventional water pipe type combustion chamber drum type. Since it becomes a small-sized combustion chamber drum, it is possible to obtain a small and lightweight heat exchanger including the heat exchange section and the combustion chamber drum.

Further, since the iron-based material such as stainless steel is used for the heat exchange drum arranged outside the heat exchange section, while ensuring corrosion resistance to ammonia, heat exchange is performed even at high temperatures during brazing. The strength of the drum is maintained, the heat exchange drum is not deformed even with a load received during transportation, and a highly reliable heat exchanger can be obtained.

Further, since the combustion chamber drum has a double structure of the heat insulating material and the cooling air passage surrounding the outer peripheral portion of the heat insulating material, not only the temperature of the combustion chamber drum can be lowered but also the heat exchanging drum can be used. It is possible to obtain a highly safe heat exchanger with low temperature.

Further, since the exhaust gas heat shield plate is provided between the heat transfer fins and the heat exchange drum in the vicinity of the heat exchange drum,
Not only the safety can be improved by lowering the temperature of the heat exchanger drum, but also the thermal efficiency is improved.

Further, since the heat insulating material is provided on the inner peripheral surface of the heat exchange drum, the temperature of the heat exchange drum can be lowered and the safety is improved.

Further, since the exhaust gas guide is arranged in the exhaust gas inflow portion on the inner circumference of the heat exchange drum, the temperature of the heat exchange drum is lowered and the safety is improved.

[Brief description of drawings]

FIG. 1 is a vertical sectional view showing a heat exchanger portion in an embodiment of the present invention.

FIG. 2 is an arrow view showing an AA cross section of the device.

FIG. 3 is a longitudinal sectional view showing an embodiment of claim 3 of the present invention.

FIG. 4 is a vertical cross-sectional view showing a heat exchanger portion showing an embodiment according to claim 4 of the present invention.

FIG. 5 is a longitudinal sectional view showing a heat exchanger portion showing an embodiment according to claim 5 of the present invention.

FIG. 6 is a vertical sectional view showing an embodiment of claim 6 of the present invention.

FIG. 7 is a vertical sectional view showing a conventional heat exchanger part.

FIG. 8 is an arrow view showing a BB cross section of the device.

[Explanation of symbols]

 13 heat transfer tubes 14 heat transfer fins 15 heat exchange drums 16 heat exchange parts 18 dry combustion chamber drums 19 heat insulating materials 20 combustion chamber drum covers 21 combustion chambers 22 burners 27 cooling air passages 28 heat insulating material covers 29 air passage covers 31 heat shield plates 32 Insulation 33 Exhaust gas guide

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Ryoichi Koga 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (72) Takahito Ishii 1006 Kadoma, Kadoma City, Osaka Matsushita Electric Industrial Co., Ltd. 72) Inventor Yasuhiro Kondo 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (72) Yasuhiro Kawamoto 1006 Kadoma, Kadoma City, Osaka Matsushita Electric Industrial Co., Ltd.

Claims (6)

[Claims] 1. A plurality of heat transfer tubes made of an iron-based material such as stainless steel, and a plurality of heat transfer fins made of a high heat conductive material such as a light alloy or copper that is penetrated and fixed to the heat transfer tubes. A heat exchanger comprising a heat exchange section and a dry combustion chamber drum using a heat insulating structure and arranged so as to cover the combustion chamber between the burner and the heat exchange section. 2. The heat exchanger according to claim 1, wherein the heat exchange drum covering the outer circumference of the heat exchange portion is made of an iron material such as stainless steel. 3. The heat exchanger according to claim 1, wherein the dry combustion chamber drum has a double structure of a heat insulating material covering the combustion chamber and a cooling air passage provided on an outer peripheral portion of the heat insulating material. 4. The heat exchanger according to claim 2, wherein a heat shield plate for exhaust gas from the burner is provided between the heat transfer fins and the heat exchange drum in the vicinity of the heat exchange drum. 5. The heat exchanger according to claim 2, wherein a heat insulating material is provided inside the heat exchange drum. 6. The heat exchanger according to claim 2, wherein in the heat exchange drum, an exhaust gas guide is provided on the inner circumference of the heat exchange drum so that the exhaust gas is directed to the inside of the exhaust gas from the burner.