WO2009119958A1

WO2009119958A1 - Oil boiler having heat exchanger with tub structure

Info

Publication number: WO2009119958A1
Application number: PCT/KR2008/006921
Authority: WO
Inventors: Tae-Sik Min
Original assignee: Kyungdong Navien Co., Ltd.
Priority date: 2008-03-28
Filing date: 2008-11-24
Publication date: 2009-10-01
Also published as: KR20090103412A

Abstract

Provided is an oil boiler having a heat exchanger with a tub structure, in which the number of welded portions is reduced and welding efficiency is enhanced by changing the structure of a heat exchanger which has been composed of a plurality of smoke tubes in the related art. The oil boiler includes a burner, a heat exchange unit in which heat transfer is performed while combustion gas generated from the burner passes through the heat exchange unit, and an exhaust hood that discharges the combustion gas passed through the heat exchange unit. The heat exchange unit includes an internal water house in which an inner structure having a cylindrical body portion is inserted into an outer structure having a cylindrical body portion and upper and lower ends of the inner structure are coupled to upper and lower ends of the outer structure, respectively, such that a space through which heating water flows is formed between an outer surface of the inner structure and an inner surface of the outer structure, and heat exchange is performed between heating water flowing in an internal space of the internal water house and combustion gas flowing outside the internal water house.

Description

OIL BOILER HAVING HEAT EXCHANGER WITH TUB

STRUCTURE

Technical Field

[1] The present invention relates to an oil boiler, and more specifically, to an oil boiler in which a heat exchanger where heating water and combustion gas are heat-exchanged with each other is formed in a tub structure, thereby enhancing welding efficiency. Background Art

[2] Boilers which are widely used as heating and hot- water supply equipment in homes are classified depending on a variety of standards such as fuel for heating water, a heat source, the position of a burner, and so on. The boilers are divided into oil boilers and gas boilers, depending on the fuel. The oil boilers use light oil or lamp oil as the fuel, and the gas boilers use LPG or LNG as the fuel. Further, the boilers may be divided into general boilers and condensing boilers, depending on the heat source. In the general boilers, heat exchange is performed by only a heat source (sensible heat) generated from combustion gas. In the condensing boilers, heat exchange is performed by condensed latent heat generated from a sensible heat exchanger. Further, the boilers are divided into upward combustion type boilers and downward combustion type boilers depending on the position of a burner which burns fuel. The upward combustion type boilers have a burner positioned in an upper portion thereof, and the downward combustion type boilers have a burner positioned in a lower portion thereof.

[3] From among the above-described boilers, in FIG. 1 is pictured a typical upward combustion type oil boiler. As shown in FIG. 1, the oil boiler includes a combustion chamber 11 formed in a lower portion thereof and a burner 12 which generates flames toward the inside of the combustion chamber 11. Above the combustion chamber 11, a plurality of smoke tubes 13 through which combustion gas passes are installed and fixed to a support plate 6 through welding, thereby forming a heat exchanger. Further, the oil boiler includes a tube body 14, which houses the combustion chamber 11 and the smoke tubes 13 and forms an external body of the boiler, and an exhaust hood 15 which is installed above the smoke tubes 13 so as to discharge combustion gas. Further, a water tank 17 in which heating water is housed is formed between the smoke tubes 13 and the tube body 14. Therefore, heating water introduced through a heating- water inlet 18 is heat-exchanged with combustion gas flowing in the smoke tubes 13, while passing through the water tank 17, and is then supplied through a heating- water outlet 19 to places where heating is required. The arrangement structure of the smoke tubes 13 installed in the tube body 14 is shown in FIG. 2 which is a horizontal cross- sectional view of FIG. 1.

[4] FIG. 3 shows an example of a conventional downward combustion type oil boiler. In the oil boiler, a combustion chamber 21 and a plurality of smoke tubes 23 are installed inside a tube body 24, and a burner 22 is installed at an upper end of the combustion chamber 23. The smoke tubes 23 are installed on a support plate 26 through welding, and an exhaust hood 25 is installed above the smoke tubes 23. Further, a water tank 25 for housing heating water is installed between the tube body 24 and the smoke tubes 23, and a heating- water inlet 28 and a heating- water outlet 29 are formed in upper and lower portions of the tube body 24, respectively. The arrangement structure of the smoke tubes 23 installed in the tube body 24 is shown in FIG. 4 which is a horizontal cross-sectional view of FIG. 3.

[5] In addition, a condensing boiler has a feature in that a plurality of heat exchangers having the above-described structure are provided. The arrangement structure of smoke tubes are the same as those of FIGS. 1 and 3.

[6] However, the above-described conventional oil boilers having an exchanger composed of a plurality of smoke tubes have a structure in which the upper ends of the smoke tubes are welded to the support plate in a state where the smoke tubes are disposed inside the tube body. Therefore, since welding is difficult to perform, defective welding may occur. Further, since the oil boilers have a large number of welded portions, manufacturing is difficult, and productivity and economical efficiency decrease.

Disclosure of Invention

Technical Problem

[7] The present invention is directed to an oil boiler having a heat exchanger with a tub structure, in which the number of welded portions is reduced and welding efficiency is enhanced by changing the structure of a heat exchanger which has been composed of a plurality of smoke tubes in the related art. Technical Solution

[8] According to an aspect of the present invention, an oil boiler having a heat exchanger with a tub structure comprises a burner; a heat exchange unit in which heat transfer is performed while combustion gas generated from the burner passes through the heat exchange unit; and an exhaust hood that discharges the combustion gas passed through the heat exchange unit. The heat exchange unit includes an internal water house in which an inner structure having a cylindrical body portion is inserted into an outer structure having a cylindrical body portion and upper and lower ends of the inner structure are coupled to upper and lower ends of the outer structure, respectively, such that a space through which heating water flows is formed between an outer surface of the inner structure and an inner surface of the outer structure, and heat exchange is performed between heating water flowing in an internal space of the internal water house and combustion gas flowing outside the internal water house.

[9] The outer structure may have small-diameter portions formed at the upper and lower ends thereof, and the inner structure may have large-diameter portions formed at the upper and lower ends thereof, the large-diameter portions having a shape corresponding to the small-diameter portions such that the large-diameter portions are coupled to the small-diameter portions. The internal water house may have a structure in which the inner structure is inserted and coupled into the outer structure.

[10] An external water house in which a second inner structure having the same shape as the inner structure is inserted and coupled into a second outer structure having the same shape as the outer structure may be installed outside the internal water house such that a space through which combustion gas flows is formed between the internal water house and the external water house, and the internal space of the internal water house and the internal space of the external water house are connected to each other such that heating water flows therethrough.

[11] Alternatively, an external water house which includes a second inner structure having a large-diameter portion formed at the upper end thereof and a second outer structure having a small-diameter portion coupled to the large-diameter portion through welding may be formed outside the internal water house such that a space through which heating water flows is formed between the second inner and outer structures, an inner bottom plate may be coupled to the lower end of the second inner structure, and an outer bottom plate may be coupled to the lower end of the second outer structure such that the internal space of the external water house is connected to a space between the inner bottom plate and the outer bottom plate.

[12] Further, facing surfaces of the outer structure of the internal water house and the second inner structure of the external water house may be formed to have a curved surface.

[13] In addition, a heat insulator may be installed at the outer circumference and bottom of the internal water house so as to form a space, through which combustion gas flows, between the internal water house and the heat insulator.

[14] Further, a first external water house and a second external water house, having an internal space through which heating water flows, may be sequentially installed outside the internal water house, and upward and downward flows of combustion gas flowing through spaces between the internal water house and the first and second external water houses may be repeated such that the oil boiler operates as a condensing boiler.

[15] As the lower end of the first external water house is coupled to a bottom portion, the flow direction of the combustion gas may be switched to an upward or downward direction at inside and outside of the first external water house.

Advantageous Effects

[16] According to the present invention, an oil boiler includes a heat exchanger with a tub structure, in which an inner structure is inserted into an external structure such that a flow path through which heating water flows is formed between an outer wall of the inner structure and an inner wall of the outer structure. Therefore, it is possible to reduce a quantity of required materials, compared with the conventional oil boiler in which a plurality of smoke tubes are disposed inside a water tank. As a result, the manufacturing cost can be reduced.

[17] Further, since the upper and lower ends of the inner and outer structures are welded in a state where the inner structure is inserted into the outer structure, the number of welded portions decreases and the welding operation is easily performed, compared with the heat exchanger of the conventional oil boiler in which the water tank and the smoke tubes are welded in a state where the plurality of smoke tubes are disposed inside the water tank. Therefore, it is possible to prevent defective welding, thereby reducing the manufacturing cost and enhancing productivity. Brief Description of the Drawings

[18] FIG. 1 is a diagram of a conventional upward combustion type oil boiler.

[19] FIG. 2 is a horizontal cross-sectional view of FIG. 1.

[20] FIG. 3 is a diagram of a conventional downward combustion type oil boiler.

[21] FIG. 4 is a horizontal cross-sectional view of FIG. 3.

[22] FIG. 5 is a diagram of an oil boiler according to a first example embodiment of the present invention.

[23] FIG. 6 is a cross-sectional view taken along line A-A of FIG. 5.

[24] FIG. 7 is an exploded perspective view of an inner structure and an outer structure which are applied to the first example embodiment of the present invention.

[25] FIG. 8 is a diagram of an oil boiler according to a second example embodiment of the present invention.

[26] FIG. 9 is a diagram of an oil boiler according to a third example embodiment of the present invention.

[27] FIG. 10 is a diagram of an oil boiler according to a fourth example embodiment of the present invention.

[28] FIG. 11 is a diagram of an oil boiler according to a fifth example embodiment of the present invention. Mode for the Invention

[29] Hereinafter, example embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, it will be appreciated by those skilled in the art that various changes may be made to these example embodiments, and the scope of the present invention is not limited to the example embodiments.

[30] [First Example Embodiment]

[31] FIG. 5 is a diagram of an oil boiler according to a first example embodiment of the present invention. FIG. 6 is a cross-sectional view taken along line A-A of FIG. 5. FIG. 7 is an exploded perspective view of an inner structure and an outer structure which are applied to the first example embodiment of the present invention.

[32] As shown in FIGS. 5 to 7, the oil boiler according to this example embodiment, which is illustrated as a downward combustion type oil boiler, includes a heat exchange unit with a tub structure. The heat exchange unit is composed of an internal water house in which an inner structure 111 and an outer structure 112 are coupled to each other.

[33] As shown in FIG. 7, the inner structure 111 has large-diameter portions I l ia and

I 1 Ib formed at upper and lower ends thereof, respectively, and a body portion 111c formed between the large-diameter portions I l ia and 11 Ib. The body portion 111c has a smaller diameter than the large-diameter portions I l ia and 11 Ib. The upper and lower ends of the inner structure 111 are opened in such a manner that the inner structure 111 has a cylindrical shape as a whole.

[34] Further, the outer structure 112 has a tub structure in which the inner structure 111 is inserted into the outer structure 112. The outer structure 112 has small-diameter portions 112a and 112b formed at upper and lower ends thereof, respectively, and a body portion 112c formed between the small-diameter portions 112a and 112b. The body portion 112c has a larger diameter than the small-diameter portions 112a and 112b. The upper and lower ends of the outer structure 112 are opened in such a manner that the outer structure 112 has a cylindrical shape as a whole.

[35] The inner structure 111 is inserted into the outer structure 112 such that the upper and lower ends of the inner structure 111 are coupled to those of the outer structure 112, respectively. That is, one large-diameter portion 11 Ia of the inner structure 111 is coupled to one small-diameter portion 112a of the outer structure 112 through welding, and the other large-diameter portion 11 Ib of the inner structure 111 is coupled to the other small-diameter portion 112b of the outer structure 112 through welding.

[36] As such, the water house 110 is formed by coupling the inner structure 111 and the outer structure 112. Between the outside of the body portion 11 Ic of the inner structure

I I I and the inside of the body portion 112c of the outer structure 112, a space 113 is formed, through which heating water heat-exchanged with combustion gas flows.

[37] In this example embodiment, it has been described that the inner and outer structures

111 and 112 have the large-diameter portions I l ia and 11 Ib and the small-diameter portions 112a and 112b, respectively. Only one of the inner and outer structures 111 and 112 may have large-diameter portions or small-diameter portions formed therein.

[38] That is, the inner structure 111 may have large-diameter portions formed at the upper and lower ends thereof, and the outer structure 112 may be formed in a straight line shape of which the diameter does not change from the upper end to the lower end, without small-diameter portions. Alternatively, the outer structure 112 may have small- diameter portions formed at the upper and lower ends thereof, and the inner structure 111 may be formed in a straight line shape of which the diameter does not changes from the upper end to the lower end, without large-diameter portions.

[39] Meanwhile, an external water house 120 in which a second inner structure 121 and a second outer structure 122 are coupled to each other is installed outside the internal water house 110. The internal and external water houses 110 and 120 compose the heat exchanger.

[40] In this case, the second inner structure 121 has large-diameter portions 121a and

121b formed at upper and lower ends thereof, and thus has the same shape as that of the inner structure 111 of the internal water house 110. The second outer structure 122 has small-diameter portions 122a and 122b formed at upper and lower ends thereof, and thus has the same shape as that of the outer structure 112 of the internal water house 110. The large-diameter portions 121a and 121b are coupled to the small- diameter portions 122a and 122b, respectively, through welding.

[41] Meanwhile, a burner 130 is installed above the internal water house 110. Since an internal space 114 of the body portion 11 Ic of the inner structure 111, in which flames of the burner 130 are to be formed, forms a combustion chamber, combustion gas generated from the burner 130 is heat-exchanged while passing through a space 124 formed between the internal and external water houses 110 and 120 via the internal space 114 of the inner structure 111, and is then discharged to the outside through an exhaust port 141 formed in an exhaust hood 140.

[42] The central portion of the exhaust hood 140 is perforated in such a manner that the burner 130 can be installed therein. The exhaust hood 140 is formed in a ring shape of which the edge is convex, and is coupled to the upper end portions of the internal and external water houses 110 and 120.

[43] Further, a panel-shaped lower plate 150 is coupled to the lower end portion of the external water house 120, and a space through which combustion gas passes is formed above the lower plate 150.

[44] The second outer structure 122 has a heating- water inlet 161 provided at one side of the lower portion thereof, through which heating water is introduced. Between the second inner structure 121 and the outer structure 111, a connection port 162 is provided. The outer structure 111 has a heating- water outlet 163 provided at one side of the upper portion thereof, through which heating water is discharged.

[45] Therefore, the heating water introduced into a space 123 within the external water house 120 through the heating-water inlet 161 passes through the space 113 within the internal water house 110 via the connection port 162, and is then supplied through the heating- water outlet 163 to places where heating is required.

[46] As shown in FIG. 6, the heat exchanger applied to the oil boiler according to this embodiment has a tub structure in which the inner structure 111 is housed in the outer structure 112, the outer structure 112 is housed in the second inner structure 121, and the second inner structure 121 is housed in the second outer structure 122.

[47] According to the above-described tub structure, only the upper and lower end portions of the inner and outer structures 111 and 112 are welded so as to construct the internal water house 110 serving as a heat exchange unit, and only the upper and lower end portions of the second inner and outer structures 121 and 122 are welded so as to construct the external water house 120 serving as a heat exchange unit. Therefore, the number of welded portions can be considerably reduced, compared with the related art. Accordingly, it is possible to prevent defective welding which may occur when a plurality of smoke tubes are welded to a support plate so as to construct a heat exchange unit, thereby facilitating the welding operation.

[48] [Second Example Embodiment]

[49] FIG. 8 is a diagram of an oil boiler according to a second example embodiment of the present invention. An internal water house 210 including an inner structure 211 and an outer structure 212, a burner 230 installed above the internal water house 210, an exhaust hood 240 having an exhaust port 241 formed therein, a heating- water inlet 261, a connection port 262, and a heating- water outlet 263, which are included in the oil boiler according to the second example embodiment of the present invention, are the same components as those of the first example embodiment. However, the oil boiler according to the second example embodiment of the present invention has a constructional feature in an external water house 220 and a bottom portion 250.

[50] The external water house 220 includes a second inner structure 221 having a large- diameter portion 221a formed at the upper end thereof and a second outer structure 222 having a small-diameter portion 222a which is coupled to the large-diameter portion 221a through welding.

[51] The bottom portion 250 includes an inner bottom plate 251 coupled to the lower end of the second inner structure 221 and an outer bottom plate 252 coupled to the lower end of the second outer structure 222. In this construction, a space 253 between the inner bottom plate 251 and the external bottom plate 252 is connected to a space 223 within the outer water house 220.

[52] Heating water introduced through the heating- water inlet 261 is heat-exchanged with combustion gas, while passing through the internal space 223 of the external water house 220 and the internal space 253 of the bottom portion 250 communicating with the internal space 223. Then, while passing through an internal space 213 of the internal water house 210 through the connection port 262, the heating water is heat- exchanged with combustion gas, and is then supplied through the heating-water discharge port 263 to places where heating is required.

[53] The oil boiler according to the second example embodiment of the present invention has a structure in which the heat exchange is performed while the heating water flows into the internal space 253 of the bottom portion 250 connected to the external water house 220, unlike the oil boiler according to the first example embodiment. Therefore, heat efficiency is further enhanced.

[54] [Third Example Embodiment]

[55] FIG. 9 is a diagram of an oil boiler according to a third example embodiment of the present invention. The oil boiler according to this example embodiment includes an internal water house 310 having an inner structure 311 and an outer structure 312, which are the same components as those of the first and second embodiments. Further, the oil boiler according to this example embodiment has the same construction as that of the second example embodiment in which a burner 330 is coupled to an upper portion of an internal water house 310, and an exhaust hood 340 having an exhaust port 341 formed therein is provided.

[56] A characteristic construction of this example embodiment is that a heat insulator 320 is installed in such a shape as to surround the outer circumference and bottom of the internal water house 310, instead of an external water house through which heating water flows.

[57] In this construction, combustion gas generated from the burner 330 is heat- exchanged with heating water while flowing through a space between the internal water house 310 and the heat insulator 320, and is then discharged to the outside through the exhaust port 341.

[58] In this case, heating water is introduced through the heating- water inlet 361 so as to be heat-exchanged while flowing through a space 313 within the internal water house 310, and is then supplied through the heating- water outlet 363 to places where heating is required.

[59] [Fourth Example Embodiment]

[60] FIG. 10 is a diagram of an oil boiler according to a fourth example embodiment of the present invention.

[61] The basic construction of this example embodiment is almost the same as that of the first example embodiment. However, the circumferential surface of an outer structure 412 composing an internal water house 410 and the circumferential surface of a second inner structure 412 composing an external water house 420 are formed to have a curved surface.

[62] Due to the curved circumferential surfaces, a turbulent flow is formed in a flow of combustion gas flowing between the outer structure 412 and the second inner structure 421, thereby enhancing heat transfer efficiency.

[63] Such a structure can be applied to the first to third example embodiments and a fifth example embodiment which will be described below.

[64] Reference numeral 411 represents an inner structure, and reference numeral 422 represents a second outer structure.

[65] [Fifth Example Embodiment]

[66] FIG. 11 is a diagram of an oil boiler according to a fifth example embodiment of the present invention.

[67] The oil boiler shown in FIG. 11 includes an internal water house 510 in which an outer structure 512 is coupled to an inner structure 511, a first external water house 520 which is installed outside the internal water house 510 and in which a second outer structure 522 is coupled to a second inner structure 521, and a second external water house 530 which is installed outside the first external water house 520 and in which a third outer structure 532 is coupled to a third inner structure 531.

[68] In this case, the inner structure 511, the second and third inner structures 521 and

531, the outer structure 512, and the second and third outer structures 522 and 532 have the same shape as those of the first example embodiment.

[69] A burner 570 is installed above the internal water house 510, and an exhaust hood

540 having an exhaust port 541 formed therein is installed above the first and second external water houses 520 and 530.

[70] The internal water house 510 and the first external water house 520 are connected to each other through a connection port 562a, and the first external water house 520 and the second external water house 530 are connected to each other through another connection port 562b. Therefore, heating water introduced through a heating- water inlet 561 passes through the second external water house 530, the connection port 562b, the first external water house 520, the connection port 562b, and the internal water house 510, and is then supplied through a heating- water outlet 563 to places where heating is required.

[71] Meanwhile, as the lower end of the first external water house 520 is attached to a bottom portion 560, combustion gas cannot pass between the lower end of the first external water house 520 and the bottom portion 560, and the flow direction of combustion gas is changed into an upward or downward direction at the inside and outside of the first external water house 520.

[72] In the structure of the oil boiler according to this example embodiment, downward and upward flows of combustion gas generated from the burner 570 are repeated. More specifically, a downward flow propagating along an internal space of the internal water house 510, an upward flow propagating along a space between the internal water house 510 and the first external water house 520, a downward flow propagating along a space between the first external water house 520 and the second external water house 530, and an upward flow propagating along the outside of the second external water house 530 are repeated and are then discharged through the exhaust port 541. Therefore, the oil boiler operates as a condensing oil boiler.

[73] Therefore, as sensible heat of the combustion gas is absorbed and latent heat of the combustion gas is then absorbed, the heat efficiency of the oil boiler is enhanced. Further, as the tab structure in which the inner and outer structures are coupled to each other is adopted as in the first example embodiment, welding efficiency is enhanced.

[74] The technical features of the first to fifth example embodiments of the present invention can be applied to an upward combustion type oil boiler as well as a downward combustion type oil boiler. Industrial Applicability

[75] In the oil boiler having a heat exchanger with a tub structure according to the present invention, the number of welded portions is considerably reduced, and welding efficiency is enhanced. Therefore, the oil boiler has industrial applicability.

[76]

Claims

[1] An oil boiler having a heat exchanger with a tub structure, comprising a burner; a heat exchange unit in which heat transfer is performed while combustion gas generated from the burner passes through the heat exchange unit; and an exhaust hood that discharges the combustion gas passed through the heat exchange unit, wherein the heat exchange unit includes an internal water house in which an inner structure having a cylindrical body portion is inserted into an outer structure having a cylindrical body portion and upper and lower ends of the inner structure are coupled to upper and lower ends of the outer structure, respectively, such that a space through which heating water flows is formed between an outer surface of the inner structure and an inner surface of the outer structure, and heat exchange is performed between heating water flowing in an internal space of the internal water house and combustion gas flowing outside the internal water house.

[2] The oil boiler according to claim 1, wherein the outer structure has small- diameter portions formed at the upper and lower ends thereof, and the inner structure has large-diameter portions formed at the upper and lower ends thereof, the large-diameter portions having a shape corresponding to the small-diameter portions such that the large-diameter portions are coupled to the small-diameter portions.

[3] The oil boiler according to claim 2, wherein an external water house, in which a second inner structure having the same shape as the inner structure is inserted and coupled into a second outer structure having the same shape as the outer structure, is installed outside the internal water house such that a space through which combustion gas flows is formed between the internal water house and the external water house, and the internal space of the internal water house and the internal space of the external water house are connected to each other such that heating water flows therethrough.

[4] The oil boiler according to claim 2, wherein an external water house which includes a second inner structure having a large-diameter portion formed at the upper end thereof and a second outer structure having a small-diameter portion coupled to the large-diameter portion through welding is formed outside the internal water house such that a space through which heating water flows is formed between the second inner and outer structures, and an inner bottom plate is coupled to the lower end of the second inner structure, and an outer bottom plate is coupled to the lower end of the second outer structure so that the internal space of the external water house is connected to a space between the inner bottom plate and the outer bottom plate.

[5] The oil boiler according to claim 3 or 4, wherein facing surfaces of the outer structure of the internal water house and the second inner structure of the external water house are formed to have a curved surface.

[6] The oil boiler according to claim 1 or 2, wherein a heat insulator is installed at the outer circumference and bottom of the internal water house so as to form a space through which combustion gas flows between the internal water house and the heat insulator.

[7] The oil boiler according to claim 1 or 2, wherein a first external water house and a second external water house, having an internal space through which heating water flows, are sequentially installed outside the internal water house, and upward and downward flows of combustion gas flowing through spaces between the internal water house and the first and second external water houses are repeated such that the oil boiler operates as a condensing boiler.

[8] The oil boiler according to claim 7, wherein as the lower end of the first external water house is coupled to a bottom portion, the flow direction of the combustion gas is switched to an upward or downward direction at inside and outside of the first external water house.