JPS6324231B2 - - Google Patents

Description

Detailed Description of the Invention The present invention relates to a heat exchanger that can be used in general heaters that burn gas or liquid fuel and exchange heat between the combustion gas and indoor air for heating. The purpose is to reduce assembly man-hours and manufacture the product at low cost.

Conventionally, this type of heat exchanger is
As shown in the example, it has a two-part structure in which heat exchange parts each having internal fins and external fins and integrally formed by aluminum die casting or press molding are combined facing each other.

1 and 2, it consists of a pair of heat exchange parts 2 surrounding a combustor 1, the outer surface of this heat exchange part 2 has an outer fin 3, and the upper part of the inner surface has an inner fin. 4, the internal fins 4 are made to protrude into the combustion gas flow path formed by the heat exchange section 2, and both internal fins are configured to intersect or face each other. The high-temperature combustion gas 6 generated from the flame 5 is pressure-equalized in the central constriction section 7, passes through the internal fins 4, exchanges heat with the forced convection air flow 8 on the outer periphery of the heat exchange section 2, and then is exhausted. It is discharged to the outside from the port 9.

However, conventional heat exchanger structures of this type have the following drawbacks.

1 The structure is extremely complex.

2. As a manufacturing method, casting such as aluminum die casting is required, and various costs are required for mold costs and equipment costs, resulting in high production costs.

3. When developing equipment according to heating capacity, new molds are required, making it difficult to share heat exchangers.

4. Since the burner is housed in the heat exchanger, serviceability of the burner is extremely poor.

It has the following drawbacks.

In FIGS. 3 and 4, a heat exchanger body 42 is formed by arranging a two-part type heat exchanger 41 formed by integrally extruding internal fins 39 and external fins 40 and facing each other to form a heat exchanger body 42. Exchanger body 42
A part of the internal fin 39 is removed by milling or the like to form a combustion chamber 44 having a lower opening 43, and a burner device 45 is installed in the lower opening of the combustion chamber 44.
A cover body 46 is provided at the upper opening of the heat exchanger main body 42 and fastened with screws 43, respectively. 47 is a combustion blower, 48 is a burner device 45
A forced convection blower is provided below, 49 is an exhaust port, and 50 is an air supply port.

The high-temperature combustion gas generated in the burner device 45 exchanges heat with the forced convection air flow of the convection blower 48 when passing through the peripheral wall of the combustion chamber 44 and the internal fin 39 provided at an intermediate upper position of the heat exchange section 41. The air is discharged to the outside air from the exhaust port 49.

The disadvantages of this kind of conventional heat exchanger structure are: 1. Internal fins 39 integrally formed by extrusion molding.
Since the combustion chamber is formed by removing a part of the combustion chamber using a milling machine or the like, the number of processing steps is large, and in reality, productivity is extremely low.

2. Cutting a part of the lower part of the external fin 40 to provide mounting parts for the essential elements of the burner, such as the ignition electrode, flame rod, and viewing window, required many man-hours and was extremely difficult to process. .

3 Since the internal fins 39 are configured to face each other as shown in FIG. 4, the gap between the gas flow paths between the internal fins 39 becomes large, making it impossible to obtain effective thermal contact for heat transfer, and at the same time, the fins Compared to the case where the internal fins 39 intersect, a sufficient heat transfer area of the internal fins 39 cannot be secured, and high thermal efficiency cannot be obtained.

4 In extrusion molding, the wall thickness of the extruded material is the same over the entire length. However, in this type of burner where the combustion chamber is constructed from aluminum extrusions close to the high-temperature part, the thickness of the aluminum material on the combustion wall is made thicker to promote heat conduction to the lower-temperature fins above. It was necessary to prevent the temperature from rising. Therefore, a thick extruded material must be used over the entire length of the heat exchanger, resulting in relatively high material costs.

5 Since the burner device 45 and lid 46 are fixed to the high-temperature heat exchanger main body 42 using screws 43, the threaded portions are damaged due to deterioration in high-temperature strength, and the sealing performance of the heat exchanger is deteriorated. As a result, combustion gas leaked into the room, damaging the originally clean heating system. Furthermore, it is possible to use thicker screws to increase the high-temperature strength of the threaded portion, but in order to ensure the thickness of the threaded portion of the heat exchanger body, it is necessary to use thicker screws over the entire length of the heat exchanger due to extrusion molding, etc. The thickness had to be increased, which was a waste of material costs.

In the present invention, the inner fin, the outer fin, and the bolt through hole are integrally formed by extrusion molding or the like. 2
The above-mentioned drawbacks of the conventional heat exchanger are solved by interposing the split heat exchanger body between the combustion section and the exhaust section and fastening them with bolts. An embodiment of the present invention will be described below with reference to FIGS. 5 to 7.

In FIGS. 5 to 7, the combustion section 10 has a rectangular burner case 11 with one side open, and a partition plate 12
The burner 13 is arranged above the air chamber 14, and the combustion chamber 15 is formed in the space below the burner 13.

The heat exchanger body 16 is a heat exchanger structure in which a plurality of external fins 18 and internal fins 19 provided on one side of the heat exchanger structure 17 and bolt through holes 20 are integrally extruded or pultruded. 17 are opposed to each other so that the internal fins 19 are interposed at approximately the midpoint between the opposing internal fins, and the side portions of the two-part heat exchanger structure 17 are fixed by welding or the like. Reference numeral 21 indicates a combustion gas passage provided between the internal fins 19 to guide combustion gas at a high flow rate, and 22 indicates a welded portion. Reference numeral 23 denotes an exhaust section, which is provided to cover the outlet section of the combustion gas flow path 21, and includes a pressure equalizing plate 24 having a through hole in the internal longitudinal direction, and an exhaust port 25 on one side, which communicates with an exhaust pipe 26. are doing. Combustion part 1
0, the heat exchanger main body 16, and the exhaust section 23, bolts 28 pass through bolt through holes 20 and are fastened with nuts 29 via packings 27, respectively. 30 is a combustion gas flow generated from a fire; 31 is a combustion air supply fan that passes through a blower tube to the air chamber 14;
is connected to.

Reference numeral 32 denotes an indoor air blower, which is comprised of a white or cross flow fan, a casing 33, and a motor, and is disposed below the heat exchanger main body 16. Reference numeral 34 indicates an indoor air intake port, 35 indicates a hot air outlet, and 36 indicates an air flow inside the aircraft. 37 is a fuel supply pipe to the burner 13, and 38 is the exterior of the hot air heater.

In the above configuration, by driving the combustion air supply fan 31 to inject fuel from the fuel supply pipe 37 to the burner 13 and igniting it by some means, a combustion flame is formed and combustion is sustained. Combustion gas generated in the combustion chamber 15 and partially heat-exchanged in the burner case 11 of the combustion section 10 hits the inner and outer walls of the heat exchanger structure 17 when passing through the combustion gas passage 21 at a high flow rate. At the provided internal fins 19 and external fins 18, heat exchange is performed with the indoor air that is forcibly sent through this section by the indoor blower 32, and further heat exchange is performed at the exhaust section 23. After being cooled down, it is discharged to the outside air through the exhaust pipe 26.

In this embodiment, a plurality of bolt through holes 20 are provided in the heat exchanger component 17, and the bolts 28 are passed through and tightened with nuts. Alternatively, a method of directly tightening the exhaust part with bolts is also considered.

According to the configuration of this embodiment, the internal fins 19, the external fins 18, and the bolt through holes 20 are integrally formed by extrusion molding or the like to face the heat exchanger component, and are fixed to the side portions of the heat exchanger component by welding or the like. Since the heat exchanger is constructed using a heat exchanger, the structure is extremely simple, and at the same time, the number of processing steps can be greatly reduced.

Furthermore, during assembly, the combustion part, heat exchanger main body, and exhaust part are connected through a gasket, and the bolt is passed through and tightened with a nut, making it easy to assemble. Man-hours can also be reduced.

In addition, by using bolt materials such as iron or stainless steel, it has stronger high-temperature strength than the conventional configuration in which screws are tightened directly to aluminum material, and it is stable under conditions of intense heat cycles such as hot air heaters. The seal of the heat exchanger seal can be ensured.

In addition, the molding molds for both heat exchanger components can be shared, and compared to die-casting molds, extrusion-type and drawing-type molds can be manufactured with simple molds, which reduces manufacturing costs. By simply changing the cutting length of the shape material, the thermal efficiency and heat exchange capacity can be set arbitrarily.

Further, the heat exchanger main body 17 has internal and external fins 19 and 18 on the inner and outer walls to form a divided heat exchanger structure, and a combustion gas flow path 21 having a small gap between the inner fins 19. The configuration provides a high degree of thermal efficiency by increasing the combustion gas flow rate and keeping the thermal boundary layer thin.

As is clear from the above description, the heat exchanger of the present invention has a heat exchanger main body that has a two-part structure that is interposed between the combustion section and the exhaust section and fastened together with bolts. Since a plurality of bolt through holes for fastening bolts are formed by integrally extruding or pultruding a pair of heat exchanger components and joining them facing each other, the following effects can be obtained.

1. There is less post-processing after molding the heat exchanger component, and the number of processing steps can be greatly reduced.

2. Can be assembled by fastening multiple bolts, greatly reducing assembly man-hours.

3. The high-temperature strength of the bolt fastening part is strong, and stable fastening strength can be obtained even during severe thermal cycles in hot air heating equipment, etc., and a reliable seal can be ensured in the seal part of the heat exchanger.

4. The heat exchanger structure is made smaller and high thermal efficiency can be achieved by having a small gap between the inner and outer fins to improve thermal contact.

5. By providing bolt through holes in the external fins, the heat transfer area of the external fins can be expanded, increasing thermal efficiency and at the same time reducing the amount of material used.

It has excellent effects such as:

[Brief explanation of the drawing]

Figures 1 and 2 are cross-sectional views of a conventional heat exchanger, Figure 3 is a cross-sectional view of another conventional example, Figure 4 is a perspective view of the main parts of Figure 3, and Figure 5 is a cross-sectional view of a conventional heat exchanger. 6 is a front view of the heat exchanger, and FIG. 7 is a sectional view taken along line A-A' in FIG. 5. 10... Combustion part, 16... Heat exchanger main body, 17
... Heat exchanger structure, 18 ... External fin, 19
...Internal fin, 23...Exhaust section, 20...Bolt through hole, 27...Putskin, 28...Bolt.

Claims (1)

[Claims] 1. A heat exchanger body with a two-part structure that is interposed between the combustion part and the exhaust part and fastened with bolts, an internal fin, an external fin, and a plurality of bolt through holes for fastening bolts on the external fin, which are integrally extruded. Alternatively, a heat exchanger formed by joining a pair of pultruded heat exchanger components facing each other.