WO2009078577A1

WO2009078577A1 - Boiler for improving heat exchanging property

Info

Publication number: WO2009078577A1
Application number: PCT/KR2008/006438
Authority: WO
Inventors: Young-Mo Kim; Byung-Cheol Jeong
Original assignee: Kyungdong Navien Co., Ltd.
Priority date: 2007-12-14
Filing date: 2008-10-31
Publication date: 2009-06-25
Also published as: KR20090063438A

Abstract

The present invention discloses a boiler for heating or supplying hot water. A boiler according to an embodiment of the present invention includes: an outer boiler tub that has a burner at the upper portion and a water tank, where fluid flows into and circulates therein, at the lower portion; combustion gas pipes that connects the combustion chamber with an external combustion gas channel through the water tank such that combustion gas heated by combustion in the combustion chamber exchanges heat with the fluid circulating in the water tank, while being discharged; a separating plate that is provided in the water tank such that the fluid collected in the water tank circulates while generating turbulent flow in the water tank.

Description

BOILER FOR IMPROVING HEAT EXCHANGING PROPERTY

Technical Field

[1] The present invention relates to a boiler used for heating and supplying hot water, more specifically a boiler for improving heat exchanging property that improves heat exchange rate of fluid by creating turbulent flow while fluid heated by a heat exchanger of the boiler flows, and makes it possible to reduce the size of the heat exchanger. Background Art

[2] In general, boilers used for heating or supplying hot water in homes commonly use oil or gas as the fuel, and recently use liquefied natural gas (LNG) as the fuel, which produces less air pollution and is convenient.

[3] Boilers that are the most commonly used in homes in recent years fall into a condensing boiler and a non-condensing boiler, depending on the ways of heat exchange of heat exchangers that heat heating water or hot water. A condensing boiler includes a sensible-heat heat exchanger that directly heats heating water using combustion heat created by a burner and a latent-heat heat exchanger that uses condensing-latent heat of exhaust gas that has passed through the sensible-heat heat exchanger. That is, the condensing boiler is equipped with both a sensible-heat heat exchanger and a latent-heat heat exchanger.

[4] FIG. 1 shows an exemplary configuration of a downward combustion type boiler among general boilers.

[5] Referring to FIG. 1, in the boiler, a water tank 31 is formed inside an outer boiler tub

30 that forms the outer body of the boiler, and a combustion chamber 40 where fuel is burned by a burner 41 and a heat exchange unit 50 that is a discharge channel of exhaust gas created in the combustion chamber 40 are formed in the water tank 31. Further, a return flow chamber 32 that connects the combustion chamber 40 with the heat exchange unit 50 is formed at the lower portion of the outer boiler tub 30, and a sound attenuation tub 53 that reduces noise, which is generated by the burner 41 when exhaust gas is discharged, and leaks outside, and a combustion gas channel 60 for discharging the exhaust gas outside are formed at the upper portion of the outer boiler tub 30.

[6] In the boiler having the above configuration, high-temperature exhaust gas is created when fuel is burned by the burner 41 in the combustion chamber 40, the exhaust gas heats heating water flowing in the water tank 31 by exchanging heat with the heating water while being discharged outside through the heat exchange unit 50 and the combustion gas channel 60, and the heated water is supplied for the object, such as heating. Further, a hot-water supply heat exchanger 90 that is wound in a coil shape may be provided around the inner circumference of the outer boiler tub 30 in the water tank 31. The hot- water heat exchanger 90 is a device that heats direct water, which flows inside independently from the heating water in the water tank 31, through the heat exchange with the heating water and then supplies hot water to the outside. Disclosure of Invention Technical Problem

[7] Boilers having the above configuration in the related art are manufactured such that as the burner 41 ignites in the combustion chamber 40, combustion gas is created by the burner 41 and heat is exchanged between the combustion gas and the heating water (fluid) circulating in the water tank 31 and the heated water is supplied while the combustion gas is discharged outside from the combustion chamber 40 through combustion gas pipes 50. However, the boilers have a problem in that when the heating water exchanges heat with the combustion gas while circulating in the water tank 31, the heating water, which is in heat exchange, does not smoothly circulate in the water tank 31 and uniformly flows from the heating water inlet to the heating water outlet, thereby reducing heat exchange property of the heating water.

[8] The present invention was designed to overcome the above problems in the related art, it is an object of the present invention to provide a boiler for improving heat exchanging property that can improve heat exchanging property between a combustion chamber and heating water in a water tank by generating turbulent flow while the heating water collected in the water tank of the boiler circulates such that convection of the heating water can be made smoothly. Technical Solution

[9] In order to achieve the above object, a boiler for improving heat exchanging property according to the present invention includes: an outer boiler tub that has a combustion chamber, where a burner is disposed, at the upper portion, and a water tank, where fluid flows into and circulates therein, at the lower portion; combustion gas pipes that connects the combustion chamber with an external combustion gas channel through the water tank such that combustion gas heated by combustion in the combustion chamber exchanges heat with the fluid circulating in the water tank, while being discharged; and a separating plate that is provided in the water tank such that the fluid collected in the water tank circulates while generating turbulent flow in the water tank, and through which the combustion gas pipes pass.

[10] In this configuration, it is preferable that the combustion gas pipe is formed to have a rectangular cross section. [11] Further, it is preferable that the separating plate is horizontally arranged to be perpendicular to the combustion gas pipe while the circumferential edge is spaced at 2mm ~ 4mm apart from the inner surface of the outer boiler tub.

[12] Further, it is preferable that liquid circulation pipes through which the fluid flows are disposed through the separating plate to reduce pressure that is generated by the separating plate while the fluid circulates in the water tank.

[13] Further, it is preferable that a plurality of the separating plates is arranged at a predetermined distance.

[14] Further, it is preferable that the diameter of the liquid circulation pipe is 10mm or less.

[15] It is preferable that a predetermined gap is defined between the separating plate and the outer surfaces of one or more combustion gas pipes of the combustion gas pipes disposed through the separating plate.

Advantageous Effects

[16] According to the boiler of an embodiment of the present invention, as turbulent flow is generated by the separating plate while the heating water collected in the water tank of the boiler circulates, convention of the heating water becomes smooth and heat exchanging property between the heating water and the combustion gas is improved. Brief Description of Drawings

[17] FIG. 1 is a cross-sectional view showing the structure of a common boiler.

[18] FIG. 2 is a cross-sectional view showing the structure of a boiler according to an embodiment of the present invention.

[19] FIG. 3 is a perspective view illustrating when separating plates are disposed in a water tank of the boiler according to the embodiment of the present invention, which is a partial cross-sectional view under the line A-A of FIG. 2.

[20] FIG. 4 is a perspective view illustrating when the separating plates of the boiler according to the embodiment of the invention are equipped with four fluid circulation pipes and one combustion gas pipe.

Best Mode for Carrying out the Invention

[21] Characteristics and advantages of the present invention will be more apparent by the following detailed description referring to the accompanying drawings. First, the terminology or terms used in the specification and claims should be construed as meanings and conceptions, which coincide with the technical spirit of the present invention, on the basis of a principle that the inventor(s) can appropriately define the conceptions of the terms for the best explanation of his/her (their) own invention.

[22] A boiler for improving heat exchanging property according to a preferred embodiment of the present invention is described in detail with reference to the ac- companying drawings.

[23] FIG. 2 is a cross-sectional view showing the structure of a boiler according to an embodiment of the present invention, FIG. 3 is a partially-cut perspective view under the line A-A of FIG. 2, for illustrating that separating plate are disposed in the water tank, and FIG. 4 is a perspective view illustrating that the separating plates of the boiler according to the embodiment of the invention are equipped with four fluid circulation pipes and one combustion gas pipe.

[24] Referring to FIGS. 2 and 4, the boiler includes a base 101 that is placed on the floor and an outer boiler tub 110 that is placed on the base 101 and has a predetermined space therein.

[25] A combustion chamber 113 is formed at the upper portion of the outer boiler tub 110 and a burner 111 that can burn fuel in the combustion chamber 113 is provided at the upper portion in the combustion chamber 113. The burner 111 applied to this embodiment is a downward combustion type.

[26] A water tank 115 where heating water, which is heat-exchanging fluid, is collected and circulated is formed under the combustion chamber 113. Combustion gas pipes 120 passing through the combustion chamber 113 at the upper portion of the water tank 115 and a return flow chamber 105 at the lower portion of the water tank 115 are disposed inside the water tank 115. The combustion gas pipes 120 are hollow pipes having rectangular cross sections.

[27] Therefore, heated combustion gas created in the combustion chamber 113 sequentially flows through the combustion gas pipes 120 and the return flow chamber 105 and is then discharged outside through an combustion gas channel 103, in which heat is exchanged between the combustion gas in the combustion gas pipes 120 and the heating water in the water tank 115, such that the heating water is heated.

[28] A water discharge port 110b through which the heating water heated in the water tank 115 is supplied to a heat pipe (not shown) is disposed at a side of the upper portion of the outer boiler tub 110, while a water return port 110a through which the heating water returns into the water tank 115 after circulating through the heat pipe is disposed at a side of the lower portion of the outer boiler tub 110.

[29] On the other hand, a return flow chamber 105 that connects the combustion gas channel 103 with the combustion gas pipes 120 to discharge the combustion gas, which has passed through the combustion gas pipes 120, through the combustion gas channel 103 as described above, is formed at the lower portion of the outer boiler tub 110. A sound attenuation tub 107 that reduces noise, which is generated when the burner is in operation and transmitted outside through the combustion gas channel 103, is provided between the combustion gas channel 103 and the return flow chamber 105. That is, in the boiler according to this embodiment, the fuel is burned by the burner 111 in the combustion chamber 113 and the high-temperature combustion gas created after the combustion sequentially flows through the combustion gas pipes 120, return flow chamber 105, sound attenuation tub 107, and combustion channel 103, and is then discharged outside.

[30] Further, a heat exchange pipe for hot- water supply 109 that surrounds the circumference of the combustion chamber 113 in a coil shape is disposed at the portion surrounding the outer surface of the combustion chamber 113 in the water tank 115. That is, as the heat exchange pipe 109 is disposed outside the combustion chamber 113 that the most rapidly increases in temperature, it is possible to the most rapidly use hot water, independently from the heating water, by circulating hot water through the heat exchange pipe for hot- water supply 109, when it needs to use hot water within a short time.

[31] Referring to FIGS. 3 and 4, separating plates 130 that improve heat exchanging property between the combustion gas pipes 120 and the heating water by allowing the heating water, which is collected in the water tank 115, to circulate while making turbulent flow in the water tank 115 are provided in the water tank 115 equipped with the combustion gas pipes 120.

[32] The separating plate 130 has combustion gas pipe holes 131 in which the combustion gas pipes 120 are fitted and is arranged horizontally to the water tank 115, and preferably, one or more separating plates may be arranged at regular intervals to further generate turbulent flow while the heating water circulates. The size of the separating plate 130 is determined herein such that the outer edge is spaced apart at a predetermined distance from the inner surface of the outer boiler tub 110, which is for further generating turbulent flow when the heating water passes between the separating plate 130 and the outer boiler tub 110, where the gap is decreased, while circulating in the water tank 115. Accordingly, convection of the heating water in the water tank 115 becomes more effective and the heat exchanging property with the combustion gas pipes 120 increases.

[33] It is preferable that the distance between the outer edge of the separating plate 130 and the inner surface of the outer boiler tub 110 is 2mm ~ 4mm. When the distance between the outer edge of the separating plate 130 and the inner surface of the outer boiler tub 110 is under 2mm, not only is the heating water not smoothly circulated in the water tank 115, but large pressure is applied to the separating plate 130 when the heating water passes between the separating plate 130 and the outer boiler tub 110. Further, the separating plate 130 supported by the combustion gas pipes 120 may be displaced, when excessive pressure is applied to the separating plate 130.

[34] On the other hand, when the distance between the outer edge of the separating plate

130 and the inner surface of the outer boiler tub 110 is above 4mm, less turbulent flow is generated when the heating water passes between the outer edge of the separating plate 130 and the outer boiler tub 110, such that the heat exchanging property decreases.

[35] Although three separating plates 130 are disposed in the water tank 115 in this embodiment, it is possible to freely change the number of separating plate 130, depending on the size of the boiler, the size of the water tank 115, and the amount of heating water.

[36] The separating plates 130 are equipped with fluid circulation pipes 133 to prevent excessive water pressure from being applied to the separating plates 130 when the heating water passes between the separating plate 130 and the outer boiler tub 110. One end of the fluid circulation pipe 133 is connected to the separating plate 130, which is disposed at the highest position of the separating plates 130, in the water tank 115 and the other end is connected to the separating plate 130, which is disposed at the lowest position of the separating plates 130, in the water tank 115. It is preferable that the diameter of the fluid circulation pipe 133 is 10mm in this embodiment.

[37] On the other hand, the combustion gas pipe 120 according to this embodiment has a rectangular cross section that is perpendicular to the longitudinal direction. The combustion gas pipe is disposed through the separating plates 130 in the water tank 115, in which a plurality of combustion gas pipes 120 is arranged in series at the center portion of the water tank 115 and radially disposed around the edge. The reason that the combustion gas pipes 120 is given the rectangular cross section is for increasing the number of combustion gas pipes 120, which are combined with the separating plates 130, and increasing the heat exchanging property with the heating water by increasing the contact area with the heating water.

[38] In disposing the combustion gas pipes 120 through the separating plates 130, one or more combustion gas pipes 120 may be disposed apart at a predetermined distance from the combustion gas pipe holes 131. This is for increasing generation of turbulent flow of the heating water by making the heating water pass through a plurality of portions of the separating plates 130 when the heating water passes through the separating plates 130, and for reducing the water pressure applied to the separating plates 130.

[39] The operation and process of the boiler having the above configuration are described hereafter.

[40] First, as the burner 111 ignites to heat the heating water, combustion gas heated by combustion in the combustion chamber 113 flows through the combustion gas pipes 120 from the combustion chamber 113, the heat of the heated combustion gas passes through the combustion gas pipes 120 while increasing temperature of the combustion gas pipes 120 and is then discharged outside the boiler after sequentially flowing through the return flow chamber 105, the sound attenuation tub 107, and the combustion gas channel 103. In this process, the heating water flowing into the water tank 115 through the water return port 110a of the outer boiler tub 110 exchanges heat by contacting with the combustion gas pipes 120 while circulating in the water tank 115, such that the temperature of the heating water increases. Further, the heating water, which has increased in temperature, is discharged outside the water tank 115 through the water discharge port 110b of the outer boiler tub 110.

[41] The heating water flowing into the water tank 115 further generates turbulent flow by the separating plates 130 disposed in the water tank 115, while circulating in the water tank 115. As a result, convection of the heating water accelerates and heat exchange with the combustion gas pipes 120 more rapidly proceeds, such that the temperature of the heating water more rapidly increases. That is, the turbulent flow of the heating water is further generated while the heating water passing between the separating plates 130 and the outer boiler tub 110, or the separating plate 130 and the combustion gas pipes 120, such that convection of the heating water becomes more effective and the heat exchanging property with the combustion pipes 120 increases.

[42] The embodiment described above is just one example for achieving the present invention, the present invention is not limited thereto, and it should be understood that, as claimed in the following claims, the spirit of the present invention includes various modification without departing from the aspects of the present invention by those skilled in the art.

Industrial Applicability

[43] As described above, when the present invention is applied to a heat exchanger of a boiler, it is possible to improve heat exchange rate of liquid and reduce the size of the heat exchanger by further generating turbulent flow while heated liquid flows in a water tank of the heat exchanger.

[44]

Claims

[ 1 ] A boiler comprising: an outer boiler tub that has a combustion chamber, where a burner is disposed, at the upper portion, and a water tank, where fluid flows into and circulates therein, at the lower portion; combustion gas pipes that connect the combustion chamber with an external combustion gas channel through the water tank such that combustion gas heated by combustion in the combustion chamber exchanges heat with the fluid circulating in the water tank, while being discharged; and a separating plate that is provided in the water tank such that the fluid collected in the water tank circulates while generating turbulent flow in the water tank, and through which the combustion gas pipes pass.

[2] The boiler according to claim 1, wherein the combustion gas pipe is formed to have a rectangular cross section that is perpendicular to the longitudinal direction.

[3] The boiler according to claim 2, wherein the separating plate is horizontally arranged to be perpendicular to the combustion gas pipe while the circumferential edge is spaced at 2mm ~ 4mm apart from the inner surface of the outer boiler tub.

[4] The boiler according to claim 3, wherein liquid circulation pipes through which the fluid flows are disposed through the separating plate to reduce pressure that is generated by the separating plate while the fluid circulates in the water tank.

[5] The boiler according to claim 4, wherein a plurality of the separating plates is arranged at a predetermined distance.

[6] The boiler according to claim 4, wherein the diameter of the liquid circulation pipe is 10mm or less.

[7] The boiler according to claim 1, wherein a predetermined gap is defined between the separating plate and the outer surfaces of one or more combustion gas pipes of the combustion gas pipes disposed through the separating plate.