EP4023939A2

EP4023939A2 - Burner, water heating apparatus, and method for controlling burner

Info

Publication number: EP4023939A2
Application number: EP21218239.8A
Authority: EP
Inventors: Jae Min An
Original assignee: Kyungdong Navien Co Ltd
Current assignee: Kyungdong Navien Co Ltd
Priority date: 2020-12-30
Filing date: 2021-12-29
Publication date: 2022-07-06
Also published as: EP4023939A3; KR20220096022A; KR102611920B1

Abstract

Disclosed is a burner comprising a fuel providing part configured to provide a fuel for a combustion reaction; an air providing part configured to send air for the combustion reaction; an ignition part configured to cause a spark such that the fuel and air provided are ignite; and a processor electrically connected to the fuel providing part, the air providing part, and the ignition part, wherein the processor is configured to: control the fuel providing part and the ignition part to provide the fuel for ignition and cause the spark; and control the air providing part such that an flow rate of the air provided at an ignition time point, at which the spark is caused and ignition occurs, is lower than a flow rate of the air provided at an air provision time point corresponding to a specific delay time after the ignition time point.

Description

TECHNICAL FIELD

The present disclosure relates to a burner, a water heating apparatus including the same, and a method for controlling the burner.

BACKGROUND

A water heating apparatus is an apparatus that heats a fluid in a container. The fluid may be water. The water heating apparatus may heat a desired area by discharging heated water to a source of demand or delivering the heated water to a passage for heating.
Accordingly, to heat water in the water heating apparatus, the water heating apparatus generally has a structure that may cause a combustion reaction by using a burner to generate flames and combustion gas and may heat the water by using heat transferred from the flames and heat transferred from the combustion gas.
The burner requires a fuel to cause a combustion reaction. The fuel may include a liquefied petroleum gas or a liquefied natural gas that is a kind of fossil fuel, but may include light oil or kerosene.
When a water heating apparatus using a burner that generates a small amount of nitrogen oxides by using a fuel of an oil type is designed, a method for supplying the air at a high speed together with the fuel may be necessary. However, when the air and the fuel supplied at the high speed meet each other for ignition, the flames may become unstable because the flames are not accurately located at a proper location. In this case, the ignition may not be smoothly made, and imperfect combustion is made to increase the amount of nitrogen oxides. Furthermore, in the case of imperfect combustion, a possibility of forming yellow flames due to soot may increase, and passages in an interior of the water heating apparatus configured such that combustion gas flows in a predetermined path may be blocked.
Furthermore, when an amount of supplied air is instantaneously increased in a state, in which ignition occurs at a proper air ratio (to achieve this, an amount of air of a blower may be changed from a low step to a high step) during an operation of the water heating apparatus using a fuel of an oil type, the ratio of the air may be significantly changed, and thus a possibility of extinguishing the flames may become higher.
Furthermore, when the ratio of the air is not constantly maintained even after the ignition, an amount of nitrogen oxides generated due to imperfect combustion may be increased.

SUMMARY

The present disclosure has been made to solve the above-mentioned problems occurring in the prior art while advantages achieved by the prior art are maintained intact.
An aspect of the present disclosure provides a burner that implements stable combustion by enhancing a seating rate of flames during ignition, a water heating apparatus including the same, and a method for controlling the burner.
The technical problems to be solved by the present disclosure are not limited to the aforementioned problems, and any other technical problems not mentioned herein will be clearly understood from the following description by those skilled in the art to which the present disclosure pertains.
According to an aspect of the present disclosure, a burner includes a fuel providing part that provides a fuel for a combustion reaction, an air providing part that sends air for the combustion reaction, an ignition part that causes a spark such that the fuel and air provided are ignite, and a processor connected to the fuel providing part, the air providing part, and the ignition part, wherein the processor is configured to control the fuel providing part and the ignition part to provide the fuel for ignition and cause the spark, and control the air providing part such that an flow rate of the air provided at an ignition time point, at which the spark is caused and ignition occurs, is lower than a flow rate of the air provided at an air provision time point corresponding to a specific delay time after the ignition time point.
According to another aspect of the present disclosure, a water heating apparatus includes a burner structure including a fuel providing part that provides a fuel for a combustion reaction, an air providing part that optionally sends air according to an intensity of any one of a low step and a high step, and an ignition part that causes a spark such that the fuel and the air provided ignite, a heat exchanger that heats water by using heat by the combustion reaction occurring in the burner structure, and a processor electrically connected to the burner structure, and the processor controls the fuel providing part and the ignition part to provide the fuel for ignition and cause the spark, and controls the air providing part such that the air is provided in a low step at a time point, at which the spark is caused and ignition occurs, and provides the air in a high step after a specific time period.
According to another aspect of the present disclosure, a method for controlling a burner includes providing air at a specific flow rate, providing a fuel, causing a spark such that the air and the fuel provided ignite, and providing air at a flow rate that is higher than the specific flow rate at an air provision time point corresponding to a specific time period from a time point, at which the spark is caused and ignition occurs.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other objects, features and advantages of the present disclosure will be more apparent from the following detailed description taken in conjunction with the accompanying drawings:

FIG. 1 is a conceptual view of an internal structure of a water heating apparatus according to an embodiment of the present disclosure;
FIG. 2 is a perspective view of a water heating apparatus such that an internal structure thereof is exposed, according to an embodiment of the present disclosure;
FIG. 3 is a perspective view illustrating a burner structure of a water heating apparatus according to an embodiment of the present disclosure;
FIG. 4 is a perspective view illustrating a burner structure of an insulation part of a water heating apparatus, from which a flame forming part is separated, according to an embodiment of the present disclosure;
FIG. 5 is a perspective view of a water heating apparatus such that an internal structure of a flame forming part thereof is exposed, according to an embodiment of the present disclosure;
FIG. 6 is a perspective view of a water heating apparatus, in which a blower tube is disassembled from a flame forming part thereof, according to an embodiment of the present disclosure;
FIG. 7 is a longitudinal sectional view of a flame forming part of a water heating apparatus according to an embodiment of the present disclosure;
FIG. 8 is a perspective view illustrating a flame holder, an ignition plug, a fuel nozzle, and a flame forming cover of a water heating apparatus according to an embodiment of the present disclosure;
FIG. 9 is a bottom view of a flame forming part of a water heating apparatus according to an embodiment of the present disclosure;
FIG. 10 is a perspective view of a flame holder of a water heating apparatus according to an embodiment of the present disclosure;
FIG. 11 is an exploded perspective view illustrating parts related to a blower in a burner of a water heating apparatus according to an embodiment of the present disclosure;
FIG. 12 is an exploded perspective view of a blower of a water heating apparatus according to an embodiment of the present disclosure;
FIG. 13 is a graph, in which control degrees of an air providing part, a fuel providing part, and an ignition part of an exemplary water heating apparatus are on a longitudinal axis and time is on a transverse axis;
FIG. 14 is a graph, in which control degrees of an air providing part, a fuel providing part, and an ignition part of a water heating apparatus according to an embodiment of the present disclosure are on a longitudinal axis and time is on a transverse axis; and
FIG. 15 is a graph, in which ratios of oxygen according to time after ignitions of burners of an exemplary water heating apparatus and a water heating apparatus according to an embodiment of the present disclosure are on a transverse axis and a longitudinal axis.

DETAILED DESCRIPTION

Hereinafter, some embodiments of the present disclosure will be described in detail with reference to the exemplary drawings. Throughout the specification, it is noted that the same or like reference numerals denote the same or like components even though they are provided in different drawings. Further, in the following description of the present disclosure, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present disclosure rather unclear.
In addition, terms, such as first, second, A, B, (a), (b), or the like may be used herein when describing components of the present disclosure. The terms are provided only to distinguish the components from other components, and the essences, sequences, orders, and the like of the components are not limited by the terms. When it is described that one element is connected, coupled, or electrically connected to another element, the element may be directly connected or coupled to the other element, but a third element may be connected, coupled, or electrically connected between the elements.
FIG. 1 is a conceptual view of an internal structure of a water heating apparatus 1 according to an embodiment of the present disclosure. FIG. 2 is a perspective view of the water heating apparatus 1 such that an internal structure thereof is exposed, according to an embodiment of the present disclosure.
Referring to FIGS. 1 and 2, the water heating apparatus 1 is an apparatus that generates heat and heat water through exchange of heat between combustion gas and water. The water heating apparatus 1 includes a combustion chamber 30, a burner structure 20, a flue tube 40, and a processor "P". The water heating apparatus 1 may include a case 10, an outer box 60, and a baffle plate 50. The case 10 may have a cylindrical shape, and a shape thereof is not limited thereto. The burner may include the burner structure 20 and the processor "P".
The combustion chamber 30 that provides a combustion space 300 that is a space for a combustion reaction may be provided in an interior of the case 10, in which other elements are installed, and the burner structure 20 may be disposed in the combustion space 300 to generate heat and combustion gas through the combustion reaction. The combustion chamber 30 may be provided on a lower side of the case 10, but a location thereof is not limited thereto.
The combustion chamber 30 may be communicated with one end of the flue tube 40. A hollow 70 disposed outside the combustion chamber 30 and the flue tube 40 to cause water to flow around the combustion chamber 30 and the flue tube 40 may be formed in the case 10. While the combustion gas generated in the combustion chamber 30 is discharged to an opposite end of the flue tube 40 through the flue tube 40, the water flowing in the hollow 70 around the flue tube 40 and the combustion chamber 30 may receive heat from the combustion gas to be heated and may be discharged.
The flue tube 40 may extend along an upward/downward direction of FIG. 1, and the water may flow through an interior thereof. The baffle plate 50 may be disposed in an interior of the flue tube 40. The baffle plate 50 may be disposed, and a path, in which the combustion gas flowing in the flue tube 40 flows, may be determined.
The flue tube 40 is an element configured such that the combustion gas flows in an interior thereof, and as illustrated, the plurality of flue tubes 40 may be disposed in water heating apparatus. The baffle plate 50 may be inserted into an interior of the flue tube 40. A one end of the flue tube 40 may be communicated with the combustion chamber 30. The flue tube 40 may cross the hollow 70 such that an opposite end of the flue tube 40 may be disposed to discharge the combustion gas to the outside. One end of the flue tube 40 may be a lower end located on a lower side, and an opposite end thereof may be an upper end located on an upper side.
The burner structure 20 is configured to cause a combustion reaction by using the air and the fuel. The fuel used by the burner structure 20 of the water heating apparatus 1 may be of an oil type. The water heating apparatus 1 may be an oil boiler. A distal end of the burner structure 20 that ejects the fuel may be located in the combustion chamber 30 to cause a combustion reaction in the combustion space 300 of the combustion chamber 30.
The outer box 60 is an element, in which internal structures of the water heating apparatus 1 described in FIG. 1 is installed. The outer box 60, as illustrated, may have a rectangular parallelepiped shape, but a shape thereof is not limited thereto. A processor "P" may be installed in the outer box 60.
The processor "P" is a constituent element including an element that may perform logical operations for performing a control command, and may include a central processing unit (CPU). The processor "P" may be connected to the elements to transmit signals according to the control commands to the element for controls, and may be connected to the sensors and the acquirers to receive the acquired information in a form of signals. Accordingly, in an embodiment of the present disclosure, the processor "P" may be electrically connected to an air providing part 22, an ignition part 24, a fuel nozzle 23, and the like included in the water heating apparatus 1. Because the processor "P" may be electrically connected to the elements, it may be connected to the elements by wire or may further include a communication module that may perform communication wirelessly for mutual communications.
The water heating apparatus 1 may further include a storage medium, and control commands performed by the processor "P" may be stored in the storage medium to be utilized. The storage medium may be a device such as a hard disk drive (HDD), a solid state drive (SSD), a server, a volatile medium, or a nonvolatile medium, but the kinds thereof are not limited thereto. In addition, the storage medium may further store data that is necessary to allow the processor "P" to perform an operation.
FIG. 3 is a perspective view illustrating the burner structure 20 of the water heating apparatus 1 according to an embodiment of the present disclosure.
The burner structure 20 is an element that causes a combustion reaction, and may include the fuel nozzle 23, the ignition part 24, and the air providing part 22. The burner structure 20 may further include a housing 21, a flame holder 25, a tube frame 28, a blower tube 26, and a fuel pump 27.
The housing 21 is an element that, after surrounding the elements of the burner structure 20 or being coupled to the elements, is coupled to the case 10 to fix relative locations of the elements of the burner structure 20 with respect to the case 10. The housing 21 may include a combustion chamber cover 211, to which the air providing part 22 and a flame forming part are coupled, and which is coupled to the case 10 to cover the opening of the combustion chamber 30, and a flame forming cover 212 that is coupled to the combustion chamber cover 211 to cover the flame forming part. Furthermore, a blower coupling part 213 configured such that the air providing part 22 is coupled to the outside of the case 10 may be formed in the combustion chamber cover 211.
The fuel pump 27 is a device that pumps the fuel received from the outside or stored in a separate fuel tank to the fuel nozzle 23 through a fuel supply pipe 273. Accordingly, the fuel pump 27 may include a fuel pressure forming part 271 including a device, as a fuel impeller 224, which may compress the fuel, and a fuel motor 272 that generates power, by which the fuel pressure forming part 271 may be driven as it is driven by electric power, and provides the generated power.
The burner structure 20 may further include a flame identifying part. The flame identifying part is an element that may identify presence of flames formed by the combustion reaction, and may be electrically connected to the processor "P". The flame identifying part may include a UV sensor that may identify whether an UV ray is generated by the flames, but any unit that may be included to identify the flames by the flame identifying part may be sufficient with no limitation. The flame identifying part may pass through the flame forming cover 212 to be coupled to the flame forming cover 212.
FIG. 4 is a perspective view illustrating the burner structure 20 of the water heating apparatus 1, from which a flame forming part is separated, according to an embodiment of the present disclosure. FIG. 5 is a perspective view of the water heating apparatus 1, such that an internal structure of a flame forming part thereof is exposed, according to an embodiment of the present disclosure. FIG. 6 is a perspective view of a water heating apparatus 1, in which the blower tube 26 is disassembled from a flame forming part thereof, according to an embodiment of the present disclosure. FIG. 7 is a longitudinal sectional view of a flame forming part of the water heating apparatus 1 according to an embodiment of the present disclosure. FIG. 8 is a perspective view illustrating the flame holder 25, the ignition part 24, the fuel nozzle 23, and the flame forming cover 212 of the water heating apparatus 1 according to the embodiment of the present disclosure. FIG. 9 is a bottom view of a flame forming part of the water heating apparatus 1 according to an embodiment of the present disclosure.
The flame forming part may include the flame holder 25, the tube frame 28, the blower tube 26, the fuel nozzle 23, and the ignition part 24. The fuel and the air are mixed in the flame forming part to generate flames, and the flames may be disposed in the combustion space 300 of the combustion chamber 30.

Flame Forming Part-Fuel Nozzle 23

The fuel providing part may include the fuel nozzle 23 and the fuel pump 27. The fuel nozzle 23 is an element that sprays the fuel of an oil type to the combustion space 300. Accordingly, the fuel nozzle 23 may be connected to the fuel pump 27 through the fuel supply pipe 273, may receive the fuel of the oil type from the fuel pump 27, and may spray the fuel into the combustion space 300 at a pressure, at which the fuel pump 27 pumps the fuel. Let's assume that a direction, in which the fuel is sprayed into the combustion space 300 by the fuel nozzle 23, is a reference direction "D". The reference direction "D" may be a direction, in which the burner structure 20 is inserted into the case 10, and may be a direction, in which the fuel nozzle 23 extends.
A flow rate of the fuel sprayed by the fuel nozzle 23 may be determined by the fuel pump 27. The fuel nozzle 23 may pass through the flame forming cover 212. A nozzle inner end 231 that is a distal end on a side of the fuel nozzle 23, which is close to the reference direction "D" and is a part, in which the outlet from which the fuel is ejected is formed, may be located inside the combustion chamber 30 as illustrated, and may have a shape, which extends from a cylindrical nozzle body 232 that passes through the housing 21 along the reference direction "D", and of which a cross-sectional area on a cross-section obtained by cutting it on a plane that is perpendicular to the reference direction "D" becomes smaller.

Flame Forming Part-Ignition part 24

The ignition part 24 is an element that ignites a mixture material, in which the sprayed fuel and the ejected air are mixed. Although it has been described in the embodiment of the present disclosure that the ignition part 24 is an ignition plug, a device that performs ignition in a method other than the ignition plug may be used as the ignition part 24. The ignition part 24 may cause an electric spark to ignite the mixture material for ignition. As the electric spark is caused in a situation, in which the fuel of the oil type is sprayed and the air is ejected and the fuel and the air are mixed to form the mixture material, the flames may be formed.
A plug body 242 may pass through the housing 21 along the reference direction "D", and a distal end of the ignition part 24, which is opposite to the reference direction "D", may be electrically connected to the processor "P" or a power source. A plug inner end 241 that is a distal end of the ignition part 24, which is close to the reference direction "D", may be disposed adjacent to the nozzle inner end 231. When viewed along the reference direction "D", the fuel nozzle 23 may be disposed at a center of the blower tube 26, and the ignition part 24 may be disposed around the fuel nozzle 23. The plug inner end 241 may have a shape that is inclined in a direction that becomes closer to the nozzle inner end 231 as it goes from the plug body 242 along the reference direction "D". The spark may be formed at the plug inner end 241.

Flame Forming Part-Blower Tube 26

The blower tube 26 is a part that surrounds the fuel nozzle 23 inserted into the combustion chamber 30 and a portion of the ignition part 24 and is connected to the air providing part 22. The blower tube 26 may have an interior space, in which the air pumped by the air providing part 22 flows, and a discharge opening that is an opening that is opened toward the combustion space 300. Accordingly, the fuel sprayed by the fuel nozzle 23 and the air pumped by the air providing part 22 may be discharged to the combustion space 300 through the discharge opening, and the flames may be formed while the spark is caused. At least a portion of the discharge opening may be covered by the flame holder 25.
The blower tube 26 may include a direct pipe part 262, which has a cylindrical external appearance, and of which a distal end that is opposite to the reference direction "D" is coupled to the housing 21. The blower tube 26 may include a tapered part 261 that is a part, of which a cross-sectional area of a cross-section obtained by cutting it on a plane that is perpendicular to the reference direction "D" as it goes from a distal end of the direct pipe part, which is close to the reference direction "D" along the reference direction "D". That is, the tapered part 261 may correspond to a distal end area of the tube that is adjacent to a distal end of the blower tube 26, which is close to the reference direction "D". The flame holder 25 may be disposed inside the tapered part 261. The tube frame 28 may be disposed inside the direct pipe part 262, and the tube frame 28 may be coupled to an inner surface of the direct pipe part 262.
An inner surface of the tapered part 261 of the blower tube 26 and an outer surface of the flame holder 25 may be spaced apart from each other by a specific interval. That is, the blower tube 26 and the flame holder 25 may not contact each other, and the entire discharge opening may not be covered by the flame holder 25. The specific interval may be not less than 0.8 mm and not more than 1.8 mm, but may become different according to a calorie generated by the burner structure 20 or other characteristics. When the blower tube 26 and the flame holder 25 are viewed along the reference direction "D", the discharge opening and the flame holder 25 may form concentric circles.

Flame Forming Part-Tube Frame 28

The tube frame 28 is an element that is disposed to fix relative locations of the elements in the flame forming part. The tube frame 28 may include a tube connector 281 coupled to an inner surface of the direct pipe part 262 of the blower tube 26, and a holder connector 282 coupled to the tube connector 281 and coupled to the flame holder 25. Accordingly, the tube frame 28 may be configured such that the blower tube 26 and the flame holder 25 are spaced apart from each other while not contacting each other, and relative locations thereof that may draw concentric circles when viewed along the reference direction "D" may be maintained.
The tube connector 281 may have a disk shape to be coupled to an inner surface of the direct pipe part 262 while contacting the inner surface of the direct pipe part 262. An opening may be formed at a center of the tube connector 281 such that the fuel nozzle 23 may be inserted into and fixed to the opening. The holder connector 282 may have a shape, such as a column, to protrude from the tube connector 281 along the reference direction "D" to be coupled to the flame holder 25, and a plurality of holder connectors 282 may be disposed to stably support the flame holder 25. A distal end of the holder connector 282, which is close to the reference direction "D", may be inserted into a coupling hole 256 formed in the flame holder 25, or may be coupled to a fastener inserted into the coupling hole 256 to be coupled to the flame holder 25.
Because the tube frame 28 is adapted to maintain a relative location relationship between the blower tube 26 and the flame holder 25, a plurality of holes may be formed to reduce a weight thereof. The ignition part 24 may pass through one of the holes.

Flame Forming Part-Flame Holder 25

FIG. 10 is a perspective view of the flame holder 25 of the water heating apparatus 1 according to an embodiment of the present disclosure.
The flame holder 25 is an element disposed to smoothly form flames. The flame holder 25 may include a holder plate 251 and a holder circumferential part 252. The flame holder 25 may further include a central opening 253, a vortex opening 254, the coupling hole 256, and a vortex wing 255, which are formed in the holder plate 251.
The holder plate 251 is an element that has a plate shape and is disposed to at least partially cover the discharge opening formed in the blower tube 26. Although it is illustrated in the embodiment of the present disclosure that the holder plate 251 has a disk shape, a shape thereof is not limited thereto.
The holder circumferential part 252 is a part that extends from a circumference of the holder plate 251 along the reference direction "D" and, may have an annular shape that protrudes in the reference direction "D" along a circumference of the holder plate 251 because the holder plate 251 has a disk shape in the embodiment of the present disclosure. However, a shape of the holder circumferential part 252 is not limited thereto.
The central opening 253 is an opening formed at a center of the holder plate 251 such that the fuel sprayed by the fuel nozzle 23 reaches the combustion space 300. The air may be discharged through the central opening 253. The central opening 253 may be circular, but may have an imperfect circular shape, of which a portion of a circumference is linear as illustrated, and a shape thereof is not limited thereto.
The vortex opening 254 is another opening formed in the holder plate 251, and a plurality of vortex openings 254 may be formed. The vertex openings 254 may be formed radially around the central opening 253. Although it has been described in the embodiment of the present disclosure that four vortex openings 254 are disposed while defining an equal angle of 90 degrees, the number and a disposition thereof are not limited thereto. As the vortex openings 254 are formed, the air provided to the blower tube 26 by the air providing part 22 may form the flames together with the fuel while flowing into the combustion space 300 and forming vortices.
The vortex wing 255 is a part disposed in the holder plate 251 adjacent to the vertex openings 254. The number of the vortex wings 255 may correspond to the number of the vortex openings 254. The vortex wing 255 may protrude from a circumference of the vortex opening 254, and may be disposed to guide the air such that the air discharged through the vortex opening 254 is rotated in the same direction.
The vortex wing 255 may protrude from a circumference of the vortex opening 254 to an outside of the combustion space 300, that is, in an opposite direction to the reference direction "D". The vortex wing 255 may be inclined in one direction with respect to the opposite direction to the reference direction "D". In detail, when the flame holder 25 is viewed along the reference direction "D", the circumference of the vortex opening 254 may have a clockwise corner and a counterclockwise corner that extend radially from the central opening 253. The plurality of vortex wings 255 may have shapes that protrude from, the clockwise corners or the counterclockwise corners of the plurality of vortex openings 254, corners in a common direction, and are inclined in the counterclockwise direction or the clockwise direction with respect to the opposite direction to the reference direction "D". Accordingly, when the flame holder 25 is viewed along the reference direction "D", the vortex wing 255 may at least partially cover the vortex opening 254. In the embodiment of the present disclosure, which is illustrated in the drawings, the plurality of vortex wings 255 have shapes that protrude from the clockwise corners of the plurality of vortex openings 254 and are inclined in a counterclockwise direction with respect to the opposite direction to the reference direction "D".
Due to the shapes of the vortex wings 255 and the vortex openings 254, the air discharged from the interior space of the blower tube 26 via the flame holder 25 may form vortices along the shapes of the vortex wings 255, and may form the mixture material better together with the sprayed fuel. Accordingly, the flames may be formed smoothly, and a lifting phenomenon of the flames being separated from the flame holder 25 may be reduced.
The coupling hole 256 may be formed in the holder plate 251 to be coupled to the holder connector 282 of the above-described tube frame 28. A plurality of coupling holes 256 may be formed, and may form an equal interval and an equal angle with respect to a center of the holder plate 251 such that the flame holder 25 is supported to be balanced.

Air Providing Part 22

FIG. 11 is an exploded perspective view illustrating parts related to the air providing part 22 in the burner structure 20 of a water heating apparatus 1 according to an embodiment of the present disclosure. FIG. 12 is an exploded perspective view of the air providing part 22 of the water heating apparatus 1 according to an embodiment of the present disclosure.
The air providing part 22 is a device for pumping the air supplied from the outside to the combustion space 300. The air providing part 22 may include an impeller 224 for compressing the air and delivering the compressed air to the blower tube 26, and a blower motor 223 that generates rotational driving power for rotating the impeller 224 and transmitting the rotational driving power to the impeller 224. The air providing part 22 may include an impeller cover 222 that may cover the impeller 224 installed in the blower coupling part 213, and a motor cover 221 that covers the blower motor 223 seated in the impeller cover 222.
The motor cover 221 may be formed such the blower motor 223 is installed in an interior thereof. The motor cover 221 may be coupled and fixed to the housing 21 while the blower motor 223 is installed therein. The motor cover 221 may include a motor installation part 2211, in which the blower motor 223 is installed, and an air introduction part 2212 that is a passage, through which the air is introduced from an outside. The air may be introduced from the outside into the motor installation part 2211 through the air introduction part 2212, and the introduced air may be delivered to the impeller 224 to be pumped to the blower tube 26.
The blower motor 223 may include a stator 2232, a shaft 2234, a rotor 2233, and a motor frame. The stator 2232 and the rotor 2233 may be disposed in the motor frame, and the motor frame may be coupled to the impeller cover 222 to fix the blower motor 223 to other elements. The stator 2232 may have an annular shape and may be formed in a form, in which a plurality of conductive coils are wound. The rotor 2233 may be inserted into an opening that is formed at a center of the stator 2232 to be opened along the reference direction "D", and may be formed of a conductive material. When an electric voltage is applied to the blower motor 223, the rotor 2233 may be rotated while the reference direction "D" is taken as an axial direction due to an electromagnetic cooperation of the stator 2232 and the rotor 2233.
The shaft 2234 that extends along the reference direction "D" is inserted into the center of the rotor 2233. The shaft 2234 may be coupled to a power transmission part 2242 of the impeller 224 that will be described below, and may transmit rotation of the rotor 2233 to the impeller 224. That is, the impeller 224 also may be rotated while the reference direction "D" is taken as the axis direction.
The impeller cover 222 may have an annular plate shape. The impeller cover 222 may be coupled to the housing 21 while covering the impeller 224 installed in the blower coupling part 213. The blower motor 223 may be coupled to an upper surface of the impeller cover 222, and the motor cover 221 may be coupled. The air introduced through the motor cover 221 may be delivered to the center of the impeller 224 through a hole formed at a center of the impeller cover 222. The shaft 2234 may pass through the hole formed at the center of the impeller cover 222 to be coupled to the power transmission part 2242 of the impeller 224.
The impeller 224 is rotated to compress and send the introduced air. Accordingly, the impeller 224 may have a special shape, and may be formed by disposing a plurality of spiral wings, which are spaced apart from each other, on an outer surface of a body having a smooth conic or circular truncated cone shape. However, a shape of the impeller 224 is not limited thereto.
An inlet of the impeller 224 is an area corresponding to an apex of a cone or an upper surface of a circular truncated cone. An annular hole between the power transmission part 2242 and a shroud 2241, which is formed at the center of the impeller 224 according to the embodiment of the present disclosure, may act as an inlet of the impeller 224. The air introduced through the inlet of the impeller 224 may be delivered to an outlet of the impeller 224 formed in a radial direction of the impeller 224 through a space between wings as the impeller 224 is rotated, and may be discharged in a compressed state. The impeller 224 may further include the shroud 2241 that covers the wings. An air passage that communicates the blower coupling part 213 and the blower tube 26 may be formed in the housing 21. The outlet of the impeller 224 may send the compressed air to the air passage.
The air providing part 22 may be controlled such that the air is pumped at a plurality of different wind speeds. The processor "P" may control the air providing part 22 such that the air providing part 22 is operated in a low step or a high step. The processor "P" may provide currents of different magnitudes to the blower motor 223 to perform a control such that the blower motor 223 is operated in a low step or a high step. In the low step, the processor "P" may provide a specific low-step current to the blower motor 223, and in the high step, the processor "P" may provide a high-step current that is higher than the low-step current to the blower motor 223 The processor "P" may control the air providing part 22 such that the blower motor 223 is operated in the low step at a time of ignition and is operated in the high step after the ignition.
The low step means a state, in which the blower motor 223 is rotated at a low-step speed such that the air is provided at a low-step wind speed that is a specific wind speed. The low-end speed may be determined a low-step air ratio of the burner structure 20 or a calorie generated. The high step means a state, in which the blower motor 223 is rotated at a high-step speed that is higher than the low-step speed such that the air is provided at a high-step wind speed that is higher than the low-step wind speed. Here, the low-step speed may be a speed corresponding to 20% to 60% of the high-step speed. For example, the low-step speed may be not less than 1400 RPM and not more than 2600 RPM, and the high-step speed may be not less than 3000 RPM and not more than 3400 RPM. Because the air providing part 22, as described above, may be controlled differently at and after the ignition time point, a lifting phenomenon of flames that may be caused by the excessively strong wind speed of the air during the ignition may be prevented, and the air may be provided at a strong wind speed to obtain a high calorie even after the ignition.
FIG. 13 is a graph, in which states of an air providing part, a fuel providing part, and flames of an exemplary water heating apparatus are on a longitudinal axis and time is on a transverse axis. FIG. 14 is a graph, in which states of the air providing part 22, a fuel providing part, and flames of the water heating apparatus 1 according to an embodiment of the present disclosure are on a longitudinal axis and time is on a transverse axis. FIG. 15 is a graph, in which ratios of oxygen of combustion gas according to time after ignitions of burners of an exemplary water heating apparatus and the water heating apparatus 1 according to an embodiment of the present disclosure are on a transverse axis and a longitudinal axis.
The graph illustrated in FIG. 13 depicts a flow rate (a thin solid line) of the air provided by the air providing part of the exemplary water heating apparatus, a state (a thick solid line) of the flames identified by the flame identifying part, and a flow rate (a dotted line) of the fuel provided by the fuel providing part according to time. FIG. 14 is a graph of the same materials as that of FIG. 13, and is different from FIG. 13 in that they are the materials of the air providing part 22 and the fuel providing part of the water heating apparatus 1 according to the embodiment of the present disclosure. This means that an intensity of the flame is weaker as the state of the flames becomes higher.
FIG. 15 depicts a ratio (a thin solid line) of oxygen expressed by a percentage according to time, which may be identified from the combustion gas after ignition in the burner of the exemplary water heating apparatus, and a ratio (a thick solid line) of oxygen according to time, which may be identified from the combustion gas after ignition in the burner of the water heating apparatus 1 according to the embodiment of the present disclosure. The ratio of oxygen means a composition ratio of oxygen in the combustion gas generated as the combustion reaction is caused by using the air and the fuel provided by the air providing part 22 and the fuel providing part in the burner. However, the values of FIG. 15 are suggested for an example, and the ratios of oxygen for stable combustion of the water heating apparatus 1 are not limited thereto.
According to control contents of the processor "P", which will be described below, a method for controlling a burner according to the embodiment of the present disclosure may be performed.
Referring to FIGS. 13 and 15, in the exemplary water heating apparatus, the ignition part may be controlled to cause a spark by the processor such that the air providing part sends air in the high step at an ignition time point t₁ that is a time point of P2, at which the spark is caused for ignition. However, it may be identified that, when the control is performed, a composition ratio of oxygen in the combustion gas continuously decreases while a percentage occupied by the gases other than oxygen in the combustion gas increases in a situation, in which an amount of supplied oxygen is maintained after an excessively large amount of oxygen is rapidly supplied at the ignition time point t₁. In this way, when the air supplied at a high speed and the fuel meet each other and an ignition occurs, the flames may become unstable or fire may be extinguished as the flames are not precisely located at proper locations.
Accordingly, as in FIG. 14, the processor "P" of the water heating apparatus 1 according to the embodiment of the present disclosure may control the fuel providing part and the ignition part 24 to provide the fuel for ignition and cause a spark, and may control the air providing part 22 such that the flow rate of the air provided at an air provision time point t₂ that corresponds to a specific delay time after the ignition time point t₁ is higher than the flow rate of the air provided at the ignition time point t₁ that is a time point, at which the spark is caused for ignition. When expressed differently, the air providing part 22 may be controlled by the processor "P" such that the air is provided in the low step at the ignition time point t₁ and the air is provided in the high step from the air provision time point t₂ corresponding to a specific time period after the ignition time point t₁. Before the spark is caused, the air may be provided in the low step. Accordingly, the water heating apparatus 1 according to the embodiment of the present disclosure may obtain a ratio of oxygen at an initial location P1. When it is considered that the thick solid lines of the graphs of FIGS. 13 and 14 is maintained at a high location, decreases to a specific location at the ignition time point t₁, and is maintained, it may be seen that the flames are not present before the ignition time point t₁, and ignition occurs after the ignition time point t₁ and flames are present.
The air provision time point t₂ may be determined according to the ratio of oxygen. In detail, the processor "P" may control the air providing part 22 to be operated in the high step while determining that the air provision time point t₂ is reached when an air provision oxygen ratio that is a ratio of oxygen located in P3 of FIG. 15 at the first time after the ignition time point t₁ is reached. The air provision oxygen ratio may be higher than a target oxygen ratio that is a ratio of oxygen that is to be finally reached by the water heating apparatus 1, which is located at P4. After the target oxygen ratio is reached, the processor "P" may control the fuel providing part and the air providing part 22 such that the flow rate of the provided fuel and the flow rate of the provided air may be fixed.
The processor "P" may experimentally obtain, store, and use a delay time (t₂-t₁) that is an interval between the air provision time point t₂, at which the air provision oxygen ratio may be achieved, and the ignition time point t₁. However, the water heating apparatus 1 according to the embodiment of the present disclosure may further include a unit that may acquire a ratio of oxygen and is electrically connected to the processor "P", and may control the air providing part 22 to be operated in the high step when the ratio of oxygen monitored by the processor "P" reaches the air provision oxygen ratio.
As the air is increased and supplied after being delayed from the ignition time point t₁, as illustrated in FIG. 15, a relatively constant ratio of oxygen may be maintained as compared with the exemplary water heating apparatus. Accordingly, a lifting phenomenon, in which the flame fly away at the ignition time point t₁ and fail to be normally maintained in the flame holder 25, may be alleviated, and stable combustion may occur after the ignition.
The processor "P" may control the fuel providing part such that the flow rate of the provided fuel may increase as time elapses from the ignition time point t₁. The processor "P" may control the fuel providing part such that the fuel starts to be provided at a fuel provision time point t₃ corresponding to a specific time before the ignition time point t₁, at which the ignition part 24 is controlled to cause a spark for ignition. The processor "P" may control the fuel providing part such that the flow rate of the provided fuel may increase as time elapses from the fuel provision time point t₃.
The processor "P" may control the fuel providing part such that a second increment that is an increment per time of the flow rate of the fuel provided from the air provision time point t₂ is larger than a first increment that is an increment per time of the flow rate of the fuel provided from the ignition time point t₁ to the air provision time point t₂. The processor "P" may control the fuel providing part such that a relationship between the flow rate of the fuel provided from the ignition time point t₁ to the air provision time point t₂ and time and a relationship between the flow rate of the fuel provided from the air provision time point t₂ and time are linear. That is, in FIG. 14, the graph of the flow rate of the fuel may be formed linearly. Because the second increment is larger than the first increment, an inclination of the graph of the flow rate of the fuel in FIG. 14 may increase with reference to the air provision time point t₂.
As can be seen from the leftmost sides of the air flow rate graphs of FIGS. 13 and 14, the processor "P" may control the air providing part 22 such that an operation of the air providing part 22 is started in a state of the high step. Further, the processor "P" may control the air providing part 22 such that the air providing part 22 is operated in a low step at a time point corresponding to a specific time after a time point, at which the air providing part 22 is operated in the high step. Because an operation of the air providing part 22 may not smoothly performed when the air providing part 22 is operated in the low step from a moment, at which the operation of the air providing part 22 is started, the operation of the air providing part 22 is started in the high step and a smooth operation state is made for a desired control.
As can be seen in FIG. 15, when the exemplary water heating apparatus is used, the ratio of oxygen may continuously decrease until a target oxygen ratio located at P4 is reached while the ratio of oxygen rapidly increases at the ignition time point t₁ and the flow rate of the provided fuel increases. Accordingly, combustion is not stably made, but flames burst out explosively at the ignition time point t₁, and then, the flames are unstably maintained and become gradually stable over time.
However, as described above, as the burner according to the embodiment of the present disclosure is controlled, a width of change may not be large until P4, at which the target oxygen ratio is achieved, is reached, via P3 from the ignition time point t₁ of P1. Accordingly, explosive flame may be hindered from being formed at the ignition time point t₁ and the air provision time point t₂, and combustion may be achieved in a form, in which stable flames become gradually stronger.
Accordingly, a problem of an amount of air increasing rapidly and flames extinguishing during ignition of a burner may be prevented, and the flames may be stably seated so that stable combustion is possible.
Furthermore, because a constant air ratio may be maintained even after the ignition, stable combustion is possible and an amount of generated nitrogen oxides may be reduced.
Although it may have been described until now that all the elements constituting the embodiments of the present disclosure are coupled to one or coupled to be operated, the present disclosure is not essentially limited to the embodiments. That is, without departing from the purpose of the present disclosure, all the elements may be selectively coupled into one or more elements to be operated. Furthermore, because the terms, such as "comprising", "including", or "having" may mean that the corresponding element may be included unless there is a specially contradictory description, it should be construed that another element is not extruded but may be further included. In addition, unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meanings as those generally understood by those skilled in the art to which the present disclosure pertains. The terms, such as the terms defined in dictionaries, which are generally used, should be construed to coincide with the context meanings of the related technologies, and are not construed as ideal or excessively formal meanings unless explicitly defined in the present disclosure.
The above description is a simple exemplification of the technical spirits of the present disclosure, and the present disclosure may be variously corrected and modified by those skilled in the art to which the present disclosure pertains without departing from the essential features of the present disclosure. Accordingly, the embodiments disclosed in the present disclosure are not provided to limit the technical spirits of the present disclosure but provided to describe the present disclosure, and the scope of the technical spirits of the present disclosure is not limited by the embodiments. Accordingly, the technical scope of the present disclosure should be construed by the attached claims, and all the technical spirits within the equivalent ranges fall within the scope of the present disclosure.

Claims

A burner comprising:
a fuel providing part configured to provide a fuel for a combustion reaction;

an air providing part configured to send air for the combustion reaction;

an ignition part configured to cause a spark such that the fuel and air provided are ignite; and

a processor electrically connected to the fuel providing part, the air providing part, and the ignition part,

wherein the processor is configured to:
control the fuel providing part and the ignition part to provide the fuel for ignition and cause the spark; and

control the air providing part such that an flow rate of the air provided at an ignition time point, at which the spark is caused and ignition occurs, is lower than a flow rate of the air provided at an air provision time point corresponding to a specific delay time after the ignition time point.
The burner of claim 1, wherein the processor is configured to:
control the fuel providing part such that a flow rate of the provided fuel increases as time elapses from the ignition time point.
The burner of claim 2, wherein the processor is configured to:
control the fuel providing part such that the fuel starts to be provided at a fuel provision time point corresponding to a specific time before the ignition time point; and

control the fuel providing part such that the flow rate of the provided fuel increases as time elapses from the fuel provision time point.
The burner of claim 2, wherein the processor is configured to:
control the fuel providing part such that an increment per unit time of the flow rate of the fuel provided from the ignition time point to the air provision time point is lower than an increment per unit time of the flow rate of the fuel provided from the air provision time point.
The burner of claim 4, wherein the processor is configured to:
control the fuel providing part such that a relationship between the flow rate of the fuel provided from the ignition time point to the air provision time point and time and a relationship between the flow rate of the fuel provided from the air provision time point and time have a linear relationship.
The burner of any of claims 1 to 5, wherein the fuel providing part is configured to:
provide a fuel of an oil type in a spraying scheme.
A water heating apparatus comprising:
a burner structure including a fuel providing part configured to provide a fuel for a combustion reaction, an air providing part configured to optionally send air according to an intensity of any one of a low step and a high step, and an ignition part configured to cause a spark such that the fuel and the air provided ignite;

a heat exchanger configured to heat water by using heat by the combustion reaction occurring in the burner structure; and

a processor electrically connected to the burner structure,

wherein the processor is configured to:
control the fuel providing part and the ignition part to provide the fuel for ignition and cause the spark; and

control the air providing part such that the air is provided in a low step at a time point, at which the spark is caused and ignition occurs, and provide the air in a high step after a specific time period.
A method for controlling a burner, the method comprising:
providing air at a specific flow rate;

providing a fuel;

causing a spark such that the air and the fuel provided ignite; and

providing air at a flow rate that is higher than the specific flow rate at an air provision time point corresponding to a specific time period after a time point, at which the spark is caused and ignition occurs.
The method of claim 8, wherein a flow rate of the fuel provided in the providing of the fuel increases as time elapses.
The method of claim 8 or 9, wherein the providing of the fuel includes:
providing the fuel at a flow rate that increase at a first increment per unit time; and

providing the fuel at a flow rate that increases a second increment per unit time, after the air provision time point, and

wherein the second increment is higher than the first increment.