Combustion equipment and water heaters
The combustion device addresses uneven fuel gas distribution by using a gas distribution unit with a partition wall and flow-diverting projection to evenly supply fuel gas to nozzles, enhancing combustion efficiency in water heaters.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- PALOMA CO LTD
- Filing Date
- 2022-12-28
- Publication Date
- 2026-06-29
Smart Images
Figure 0007881464000001 
Figure 0007881464000002 
Figure 0007881464000003
Abstract
Description
Technical Field
[0001] The present disclosure relates to a combustion device in a water heater that can distribute and supply fuel gas to a plurality of burners and switch the combustion stages, and a water heater equipped with the combustion device.
Background Art
[0002] The water heater includes a combustion device having a burner and a heat exchanger in a housing, and heats the water passing through the heat exchanger by the combustion exhaust gas of the burner that ignites and burns a mixture of fuel gas and combustion air to produce hot water. The burners installed in the combustion device are flat and a plurality of them are arranged in the thickness direction and unitized. A gas distribution unit is provided upstream of the burner unit. As disclosed in Patent Document 1, this gas distribution unit includes a main body provided with a plurality of nozzles arranged side by side in the left-right direction in upper and lower two stages corresponding to each burner, and a cover plate (cover body) assembled to the front surface of the main body. A gas passage (main flow path) extending in the left-right direction and a plurality of distribution flow paths branched from the gas passage are partitioned and formed by a recess formed in the main body and a throttle portion provided in the cover plate. Each distribution flow path corresponds to a plurality of burner groups having different numbers of burners. Gas inlets communicating with the gas passage are respectively formed at the upstream ends of each distribution flow path. Each gas inlet can be opened and closed by an electromagnetic valve. In this combustion device, the controller can adjust the number of burners to be burned by opening and closing each electromagnetic valve to select the combination of distribution flow paths to which fuel gas is supplied.
Prior Art Documents
Patent Documents
[0003]
Patent Document 1
Summary of the Invention
Problems to be Solved by the Invention
[0004] Figure 8 shows Figure 4 of Patent Document 1, along with some of the reference numerals. In this main body 23, the recesses 40 to 41 that form each distribution channel are provided with a fan-shaped introduction section S1 that widens from left to right as it extends upward downstream from the gas inlet 43, and a distribution section S2 that is continuous with the upper end of the introduction section S1 and has a plurality of nozzles 34 arranged in parallel. A gas opening / closing section for supplying fuel gas is provided on the lower back side of the main body 23 in the left-right direction. Of the recesses 40 to 41, recess 40, located on the far left and communicating with the left end of the gas opening / closing section, has the largest number of nozzles 34, and therefore the introduction section S1 and distribution section S2 have the largest area, with a wider width than the other recesses 41 and 42. However, after the fuel gas flows to the left through the gas opening / closing section, it flows with the same momentum into the recess 40 with the largest area through the gas inlet 43. As a result, even within the recess 40, as indicated by the solid arrow a, it tends to rise towards the left side of the inlet section S1, which is downstream in the flow direction, due to the momentum of the flow. Consequently, an uneven flow occurs within the inlet section S1 with the largest area, and the fuel gas is not supplied evenly to each nozzle 34 of the distribution section S2 (especially the rightmost nozzle 34).
[0005] Therefore, the present disclosure aims to provide a combustion device and a water heater that can reduce the uneven flow of fuel gas in a large-area distribution channel and supply fuel gas evenly to each nozzle. [Means for solving the problem]
[0006] To achieve the above objective, the first configuration of this disclosure comprises an inner case housing a plurality of burners, It is assembled into the inner case. A gas distribution unit comprising: multiple sets of nozzles arranged in the left-right direction as upper and lower tiers, each injecting fuel gas into a burner; a main flow path into which fuel gas is introduced and extends in the left-right direction; at least two distribution flow paths located above the main flow path and having a fuel gas inlet at its lower end that communicates with the main flow path, each branching the fuel gas to multiple groups of nozzles with different numbers of nozzle sets; multiple valve chambers communicating with each inlet; and solenoid valves provided in each valve chamber that can open and close each inlet; A combustion device in which the number of burners can be switched by switching the supply of fuel gas to each distribution channel by opening and closing each inlet with each solenoid valve, In the gas distribution unit, One distribution channel, which has more nozzle sets than other distribution channels, is connected to either the left or right end of the main channel via an inlet, and includes an introduction section where the channel width widens as it extends upward from the inlet, and a distribution section connected to the upper end of the introduction section where nozzle sets are arranged in the left-right direction, and the distribution section has partition walls that extend downward from the upper end of the distribution section to at least the space between two rows of nozzles, dividing the left-right rows of nozzles into multiple rows, The main flow path has an upper surface extending in the left-right direction and side surfaces that slope downward from the upper end, moving away from the other ends on the left and right. An opening communicating with the valve chamber is provided at the corner between the upper surface and the side surfaces. When a third virtual line is extended toward the introduction and distribution sections, passing through the intersection of a first virtual line extending horizontally along the top surface in a front view and a second virtual line extending inclined vertically along the side surface in a front view, and bisecting the angle between the first and second virtual lines, one partition wall that intersects with or is closest to the third virtual line has an extension formed thereon that extends downward to at least the height of the lower nozzle. To achieve the above objective, the second configuration of this disclosure is a water heater comprising a combustion device of the first configuration and a heat exchanger through which the combustion exhaust from the burner of the combustion device passes, characterized in that it is capable of dispensing hot water by heat exchange between water passing through the heat exchanger and the combustion exhaust from the burner. [Effects of the Invention]
[0007] According to this disclosure, the main flow of fuel gas from the inlet to one side of the introduction section collides with the partition wall and splits into left and right branches, which are then guided to the other side of the introduction section and distribution section. Therefore, the uneven flow of fuel gas in the large distribution channel is reduced, and fuel gas can be supplied evenly to each nozzle. [Brief explanation of the drawing]
[0008] [Figure 1] This is a front view of the water heater with the front cover removed. [Figure 2] This is a disassembled perspective view of the gas distribution unit from the front. [Figure 3] This is a rear-view disassembled perspective of the gas distribution unit. [Figure 4] This is a front view of the main unit. [Figure 5] Figure 1 shows an enlarged cross-sectional view along line AA (only the gas distribution unit is shown). [Figure 6] This is a perspective view of the main unit from the front. [Figure 7] This is a perspective view from the rear of the main unit. [Figure 8] This is a front view of the main body of a conventional gas distribution unit. [Modes for carrying out the invention]
[0009] The embodiments of this disclosure will be described below with reference to the drawings. Figure 1 is an explanatory diagram showing an example of a water heater, displaying the front view with the front cover removed. The water heater 1 has a combustion device 3, a heat exchanger 4, and an exhaust section 5 installed in a square box-shaped housing 2. The combustion device 3 includes an inner case 6 that houses a burner unit (not shown). The burner unit is formed by arranging a plurality of lean- rich burners that are flat in the left - right direction in the left - right direction. On the front surface of the inner case 6, a gas distribution unit 7 for distributing and supplying fuel gas to each burner group of lean - rich burners with different numbers is assembled. An air supply fan 8 for supplying combustion air is assembled on the lower left side of the combustion device 3. Below the combustion device 3 and on the right side of the appliance, a controller 9 having a control circuit board is arranged. In the exhaust section 5, a horizontally long exhaust cylinder 10 that penetrates the front cover and protrudes forward is formed.
[0010] The heat exchanger 4 is of a fin - tube type having heat transfer tubes that penetrate a plurality of fins arranged in parallel in the thickness direction in a meandering shape. A water supply pipe 11 is connected to the inlet end of the heat transfer tube, and a hot water outlet pipe 12 is connected to the outlet end of the heat transfer tube. On the lower surface of the housing 2, a water inlet 13 to which an external water pipe is connected and a hot water outlet 14 to which an external pipe to a hot water tap is connected are provided. The upstream end of the water supply pipe 11 is connected to the water inlet 13, and the downstream end of the hot water outlet pipe 12 is connected to the hot water outlet 14, respectively. Also, on the lower surface of the housing 2, a gas inlet 15 to which an external gas pipe is connected is provided. The gas inlet 15 is connected to the gas distribution unit 7 in the housing 2 via a gas proportional valve unit 16 having a proportional valve 17 and a primary solenoid valve 18 on its upstream side. The gas distribution unit 7 is assembled on the front surface of the inner case 6 so as to close an opening at the lower front of the inner case 6. A frame rod 19 and a discharge electrode 20 are inserted and connected to the front surface of the inner case 6 above the gas distribution unit 7.
[0011] As shown in FIGS. 2 and 3, the gas distribution unit 7 has a horizontally long flat shape formed by a rear main body 25 and a front cover body 26 screwed to the main body 25 from the front. A seal body 27 is interposed between the main body 25 and the cover body 26. The main body 25, which is made of die-cast aluminum, has a deep main recess 28 that protrudes to the rear, formed in the left-right direction at its lower end. The right end of the main recess 28 is bent downward, and a gas inlet 29 is formed through its lower end. The gas outlet (not shown), which is provided at the upper end of the gas proportional valve unit 16, is connected to the gas inlet 29 from the rear. On the upper part of the main body 25, 20 pairs of nozzles 30, 30 are arranged linearly in the left-right direction, each forming a pair in two tiers, upper and lower, projecting backward. On the front of the main body 25, around the main recess 28 and all the nozzles 30, an outer perimeter frame 31 is formed, consisting of continuous protrusions projecting forward. Inside the outer perimeter frame 31, partition frames 32, 32... are formed, dividing the arrangement of nozzles 30 into predetermined groups and separating the main recess 28 from the area above it. These partition frames 32 divide the area above the main recess 28, forming a first recess 33, a second recess 34, and a third recess 35 side by side from left to right. The first to third recesses 33 to 35 are all shallower than the main recess 28.
[0012] As shown in Figure 4, the first to third recesses 33 to 35 each include first to third introduction sections 36 to 38 that extend upward from the lower end and gradually widen in width, and first to third distribution sections 39 to 41 that communicate with the upper parts of the first to third introduction sections 36 to 38 and extend in the left-right direction, including an arrangement of nozzles 30. Thirteen sets of nozzles 30 are arranged in the first distribution section 39, four sets of nozzles 30 are arranged in the second distribution section 40, and three sets of nozzles 30 are arranged in the third distribution section 41. Therefore, the first distribution section 39 is the longest in the left-right direction, and the first introduction section 36 has a front-view fan shape, widening in width from the lower end upward and connecting to the first distribution section 39. For this reason, the area of the first recess 33 is larger than that of the second and third recesses 34 and 35. Inside the first distribution section 39, four partition walls 42, 42... are formed, which are formed downward from the upper part of the outer peripheral frame 31 and partition 13 sets of nozzles into groups of 2, 2, 3, 3, and 3 from left to right. Therefore, the first distribution section 39 is partitioned into a first region E1 including two sets of nozzles 30, a second region E2 including two sets of nozzles 30, a third region E3 including three sets of nozzles 30, a fourth region E4 including three sets of nozzles 30, and a fifth region E5 including three sets of nozzles 30 from left to right. The fifth region E5 is located on the right side of directly above a first inlet 45 described later. Inside the second distribution section 40, partition walls 42 that partition four sets of nozzles 30 into groups of two are also formed. On each partition wall 42, circular screw fastening parts 43 with screw holes for fastening the lid body 26 are formed in a front view. The screw fastening parts 43 are also formed on the outer peripheral frame 31 and the partition frame 32.
[0013] At the lower ends of the first to third introduction sections 36 to 38, first to third inlets 45 to 47 are formed to penetrate. The first to third inlets 45 to 47 are circular in a front view, and here, the diameter of the first inlet 45 is larger than the diameters of the second and third inlets 46 and 47. The centers O1 to O3 of the first to third inlets 45 to 47 are located at the same height in the vertical direction. As shown in FIG. 5, behind the first to third inlets 45 to 47, cylindrical first to third valve chambers 48 to 50 that protrude rearward and open are formed. In the first to third valve chambers 48 to 50, first to third solenoid valves 51 to 53 are detachably attached by screws from the rear. The first to third solenoid valves 51 to 53 open and close the first to third inlets 45 to 47 from the rear. As shown in FIGS. 6 and 7, the first and second valve chambers 48 and 49 protrude into the main recess 28 and communicate with the main recess 28 through first and second openings 54 and 55 formed in an arc shape on the circumferential surface. As shown in Figure 4, the upper surface 56 of the main recess 28 extends horizontally in a front view along a first virtual straight line L1 that extends horizontally through the centers O1 to O3 of the first to third inlets 45 to 47. The left side surface 57 of the main recess 28 extends inclined in a front view along a second virtual straight line L2 that slopes to the right as it extends upward through the center O1 of the first inlet 45. The first valve chamber 48 protrudes its lower side into the main recess 28 between the upper surface 56 and the left side surface 57, opening the first opening 54 over the entire range of the angle α formed between the upper surface 56 and the left side surface 57. Therefore, the first opening 54 is formed at a phase rotated to the right of directly below the center O1 of the first inlet 45. A third opening 58 is formed on the upper left side of the third valve chamber 50. The third opening 58 communicates with the upper (downstream) side of the second inlet 46 in the second introduction section 37 via a connecting passage 59 that extends in the left-right direction.
[0014] Furthermore, a flow-diverting projection 60 is provided in the first inlet 36. The flow-diverting projection 60 is oval in shape when viewed from the front, with its long axis running horizontally, and is located slightly above the center of the first inlet 36 in the vertical direction. In the horizontal direction, the flow-diverting projection 60 is located slightly to the left of the center O1 of the first inlet 45. The flow-diverting projection 60 protrudes forward from the bottom surface of the first recess 33 to the same height as the depth of the first recess 33. In the outer frame 31, the inclined portion forming the left side of the first introduction section 36 is tangent to the first inlet 45 and connects to the outer circumference of the nozzle 30A (hereinafter, when distinguishing between them, the symbols "A", "B", "C", etc. will be added. The same applies to other components) at the lower left corner of the first region E1 of the first distribution section 39, forming a left-side virtual straight line L. L It is formed in a roughly straight line along the line. However, the inclined portion of the partition frame 32 that forms the right side of the first introduction section 36 becomes tangent to the first inlet 45 and connects to the outer circumference of the nozzle 30B at the lower right corner of the fifth region E5 of the first distribution section 39 with a virtual straight line L on the right side. R A protruding portion 65 is formed that extends further towards the center (upper left side).
[0015] This protruding portion 65 comprises a lower edge portion 66 that bulges in an arc shape toward the space between the first inlet 45 and the diversion projection 60, a middle edge portion 67 that extends linearly from the upper end of the lower edge portion 66 toward the right end of the first distribution portion 39, and an upper edge portion 68 that bends to the right from the upper end of the middle edge portion 67 and extends horizontally below the fifth region E5. This upper edge portion 68 closes the lower right side of the fifth region E5. The corner 69 between the upper edge 68 and the middle edge 67, which is the left end of the upper edge 68, is located vertically between the second nozzle 30C and the third nozzle 30D from the right. Therefore, the upper edge 68 surrounds approximately 60% of the right end of the fifth region E5 from below, and the space between the corner 69 and the screw-fastened portion 43 of the partition wall 42A at the right end serves as the fuel gas inlet 70 into the fifth region E5. Thus, the fifth region E5 is in a semi-sealed state, surrounded by the outer frame 31, partition frame 32, upper edge 68, and partition wall 42A, except for the inlet 70. Here, if we define a third virtual line L3 that, in a front view, passes through the center O1 of the first inlet 45 and bisects the angle α between the first virtual line L1 and the second virtual line L2 (i.e., bisecting the first opening 54), then this third virtual line L3 is closest to the second partition wall 42B from the left in the first distribution section 39. This partition wall 42B has an extension 71 that extends downward from the screw-fastened section 43 and is longer than the other partition walls 42. The lower end of this extension 71 reaches between the lower row of nozzles 30, 30 located on the left and right.
[0016] The cover 26 is made of sheet metal and covers the area enclosed by the outer frame 31 and the area outside of it from the front. The cover 26 has a main bulge 75 located in front of the main recess 28, a first bulge 76 located in front of the first recess 33, a second bulge 77 located in front of the second distribution portion 40 of the second recess 34, and a third bulge 78 located in front of the third recess 35, all of which protrude forward. The sealing body 27 is connected in a mesh-like manner around the main recess 28 and the first to third recesses 33 to 35 of the main body 25, between the main recess 28 and the first to third recesses 33 to 35, and between the first to third recesses 33 to 35, etc., sealing the space between the main body 25 and the lid 26.
[0017] Therefore, by positioning the seal body 27 on the front surface of the main body 25 to which the first to third solenoid valves 51 to 53 are assembled, and then covering it with the cover body 26 and fastening it with screws, a main flow path 80 is formed inside the gas distribution unit 7 by the main recess 28 and the main bulge 75, communicating with the gas inlet 29 and the first and second openings 54 and 55. In addition, a first distribution flow path 81 communicating with the first inlet 45 is formed by the first recess 33 and the first bulge 76, and a second distribution flow path 82 communicating with the second inlet 46 is formed by the second recess 34 and the second bulge 77. Furthermore, a third distribution flow path 83 communicating with the third inlet 47 is formed by the third recess 35 and the third bulge 78. However, the third inlet 47 is connected to the second distribution channel 82 downstream of the second inlet 46 by the third valve chamber 50 and a connecting channel 59 whose front surface is closed by the cover 26. The gas distribution unit 7 can be assembled by setting the main body 25 on the front of the inner case 6, connecting the gas proportional valve unit 16 to the gas inlet 29, and securing it with screws.
[0018] In the water heater 1 configured as described above, when the hot water tap connected to the piping of the hot water outlet 14 is opened and water flows into the appliance, the controller 9 detects this and opens the main solenoid valve 18 of the gas proportional valve unit 16, and controls the proportional valve 17 to a predetermined opening degree at the time of ignition. The controller 9 opens the first to third solenoid valves 51 to 53 of the first to third distribution passages 81 to 83, and operates the air supply fan 8 to supply combustion air. As a result, fuel gas is supplied to the main passage 80 of the gas distribution unit 7 via the gas proportional valve unit 16. The fuel gas flowing into the main passage 80 flows into the first and second valve chambers 48 and 49 from the first and second openings 54 and 55, and flows into the first and second distribution passages 81 and 82 via the first and second inlets 45 and 46. A portion of the fuel gas flowing into the second distribution passage 82 flows into the third valve chamber 50 via the third opening 58 from the connecting passage 59, and flows into the third distribution passage 83 from the third inlet 47. The fuel gas flowing into each distribution passage 81 to 83 rises along the respective inlet sections 36 to 38 and diffuses to the respective distribution sections 39 to 41, and is supplied to each enrichment burner from each nozzle 30.
[0019] Then, the controller 9 activates the igniter, and when the discharge electrode 20 discharges continuously, the fuel mixture ejected from the flame holes of each rich / poor burner burns. The combustion exhaust from the burner unit is heat-exchanged with water passing through the heat transfer tubes of the heat exchanger 4, and the resulting hot water at the set temperature is discharged from the outlet pipe 12. The controller 9 adjusts the opening of the proportional valve 17 according to the required combustion amount, adjusts the amount of fuel gas supplied from the gas proportional valve unit 16, and continuously changes the rotation speed of the intake fan 8 to maintain a predetermined air-fuel ratio. Furthermore, the controller 9 controls the opening and closing of the first to third solenoid valves 51 to 53 of the gas distribution unit 7 according to the required amount of combustion, thereby selecting a group of burners for each distribution channel 81 to 83 and controlling the number of combustions in stages.
[0020] For example, when burning only the central burner group (four rich / poor burners) corresponding to the second distribution channel 82, the controller 9 closes the first solenoid valve 51 and the third solenoid valve 53 and opens only the second solenoid valve 52. As a result, fuel gas flows from the main channel 80 through the second valve chamber 49 into the second distribution channel 82 and burns the central burner group (single-stage combustion). Furthermore, when igniting the central burner group and the right-side burner group (three rich / mild burners), the controller 9 closes the first solenoid valve 51 and opens the second solenoid valve 52 and the third solenoid valve 53. As a result, the fuel gas flows from the main flow path 80 through the second valve chamber 49 into the second distribution flow path 82, and also flows into the third distribution flow path 83 through the connecting flow path 59 and the third valve chamber 50, igniting the central and right-side burner groups (seven rich / mild burners) (two-stage combustion). Furthermore, when igniting the central burner group and the left burner group (13 rich / mild burners), the controller 9 opens the first solenoid valve 51 and the second solenoid valve 52 and closes the third solenoid valve 53. Thus, the fuel gas flows from the main flow path 80 through the first and second valve chambers 48 and 49 to the first and second distribution flow paths 81 and 82, igniting the central and left burner groups (17 rich / mild burners) (three-stage combustion). When all burner groups are to be combusted, the controller 9 opens the first to third solenoid valves 51 to 53. As a result, fuel gas flows from the main flow path 80 through the first and second valve chambers 48 and 49 to the first and second distribution flow paths 81 and 82, and also flows into the third distribution flow path 83 through the connecting flow path 59 and the third valve chamber 50, combusting all burner groups (20 rich and light burners) (four-stage combustion). In this way, the number of burning burners from the 20 burners can be switched between four levels.
[0021] When fuel gas flows from the main flow path 80 to the first distribution flow path 81, the fuel gas that has flowed into the main flow path 80 flows into the first valve chamber 48 through the first opening 54 and flows into the first distribution flow path 81 from the first inlet 45. At this time, the main stream of fuel gas flows from the first inlet 45 into the first introduction section 36 with the same momentum as flowing from right to left through the main flow path 80. As shown by the solid arrow a in Figure 4, it flows to the upper left, to the left of the third virtual straight line L3. However, since the first distribution section 39 on the downstream side has a partition wall 42B and an extension 71 at its lower end, the main stream of fuel gas collides with the partition wall 42B and the extension 71 and disperses to the left and right. Therefore, the fuel gas does not concentrate in the nozzles 30 of the first region E1 and second region E2 on the left side, but is also supplied to the nozzles 30 of the third region E3 and fourth region E4 on the right side.
[0022] Meanwhile, a portion of the fuel gas byflow flows upward from the first inlet 45 into the first introduction section 36, as indicated by the dotted arrow b1. A portion of this byflow collides with the flow-dividing projection 60 located above, splitting into left and right sections as shown by the dotted arrow c, and flows into the third region E3 on the left and the fourth and fifth regions E4 and E5 on the right. Then, another portion of the fuel gas byflow flows from the first inlet 45 to the first introduction section 36 in the direction of extension of the left side surface 57, as shown by the dotted arrow b2. However, since the lower edge 66 of the protruding section 65 bulges out on the upper right side of the first inlet 45, the fuel gas that collides with the lower edge 66 changes angle and is guided towards the flow diversion projection 60. The other portion of the guided byflow collides with the flow diversion projection 60 and flows into the fourth region E4 and the fifth region E5. In this way, the fuel gas flowing into the fifth region E5 enters the fifth region E5 through the narrow inlet 70, generating a vortex. As a result, the fuel gas is evenly distributed to the nozzle 30 within the fifth region E5.
[0023] (Effects of disclosure regarding flow diversion protrusions) In the water heater 1 of the above configuration, the combustion device 3 includes an inner case 6 that houses a plurality of burners, a plurality of nozzles 30 assembled to the inner case 6 and arranged in the left-right direction to eject fuel gas to each burner, a main flow path 80 into which fuel gas is introduced and extends in the left-right direction, first to third distribution flow paths 81 to 83 (an example of at least two distribution flow paths) arranged above the main flow path 80 and communicating with the main flow path 80, each having first to third inlets 45 to 47 (an example of inlets) of fuel gas at their lower ends, and branching the fuel gas to each group of nozzles with a different number of nozzles 30, and first to third solenoid valves 51 to 53 (an example of solenoid valves) that can open and close the first to third inlets 45 to 47. The combustion device 3 can switch the number of burners burning by switching the supply of fuel gas to the first to third distribution channels 81 to 83 by opening and closing the first to third inlets 45 to 47 using the first to third solenoid valves 51 to 53. In the gas distribution unit 7, the first distribution channel 81 (an example of at least one distribution channel) which has more nozzles 30 than the second and third distribution channels 82, 83 (an example of other distribution channels), includes a first introduction section 36 (an example of an introduction section) whose channel width widens as it extends upward from the first inlet 45, and a first distribution section 39 (an example of a distribution section) in which nozzles 30 are arranged in the left-right direction and communicate with the upper end of the first introduction section 36. Furthermore, the first inlet 36 is provided with a flow-dividing projection 60 for dividing the fuel gas supplied from the first inlet 45 to the first inlet 36 to the left and right, and on the right side edge of the first inlet 36 (an example of one of the left or right side edges), there is a lower edge 66 (an example of a guide portion) of an overhang 65 that bulges inward from the first inlet 36 and guides the fuel gas flowing from the first inlet 45 into the first inlet 36 toward the flow-dividing projection 60. This configuration reduces the uneven flow of fuel gas in the large-area first distribution channel 81, allowing for a more uniform supply of fuel gas to each nozzle 30.
[0024] The first distribution channel 81, which is provided with the flow-dividing projection 60, is in communication with the left end of the main channel 80 (an example of either the left or right end) via the first inlet 45. The left side surface 57 (an example of the side surface) of the main channel 80 at the left end is an inclined surface that slopes away from the right end of the main channel 80 as it moves downward from the top end. Therefore, the fuel gas that has flowed to the left end of the main flow path 80 can be directed towards the right side of the first inlet 36, where fuel gas flow is less favorable, by the inclined left side surface 57, thereby reducing the uneven distribution of fuel gas to the left side. The diversion projection 60 has a horizontally elongated shape that extends in the left-right direction. Therefore, the fuel gas rising from the first inlet 45 through the first introduction section 36 can be reliably divided to the left and right.
[0025] Next, we will explain examples of changes to the disclosure related to flow diversion protrusions. The shape of the diversion projection is not limited to the above form. The diversion projection is not limited to an oblong shape when viewed from the front; it may also be an ellipse or a quadrilateral when viewed from the front. The length of the diversion projection in the left-right direction may be longer than the above form. The diversion projection may also be circular when viewed from the front. The lower part of the diversion projection may be tapered, with the width decreasing from left to right as it goes downwards. The position of the diversion projection is not limited to the above configuration; it may be positioned closer to or further away from the inlet than in the above configuration. Multiple flow-diverting protrusions may be provided. In the above configuration, the nozzles provided in the distribution section are arranged in a left-right direction as an upper-lower pair, but the nozzles may also be arranged in a single row in the left-right direction. In the above configuration, a flow-diverting projection is provided in the leftmost distribution channel that communicates with the left end of the main flow channel. However, if the area is large, a flow-diverting projection may be provided in the rightmost distribution channel, or in any other distribution channel where fuel gas distribution is uneven. In the above configuration, the flow-dividing projection is provided on the main body, but the flow-dividing projection may also be provided on the lid, or the projection provided on the main body and the projection provided on the lid may be brought into contact with each other to form the flow-dividing projection. The side surfaces of the main flow path may be formed in a vertical direction rather than being inclined. In the above configuration, the guide section is provided only on the right side of the inlet where the flow-dividing projection is located. However, the guide section may be provided only on the left side of the inlet, or on both the left and right sides of the inlet. In the disclosure relating to the flow-diverting projection, disclosure relating to the overhang portion and / or disclosure relating to the partition wall with extension portion may be omitted. However, if the overhang portion is omitted, the guide portion may be partially bulged.
[0026] (Effects of disclosure regarding the protruding portion) The combustion device 3 in the water heater 1 of the above configuration includes an inner case 6 that houses a plurality of burners, a plurality of sets of nozzles 30 assembled in the inner case 6 and arranged in the left-right direction as upper and lower two-tiered sets that inject fuel gas to each burner, a main flow path 80 into which fuel gas is introduced and extends in the left-right direction, first to third distribution flow paths 81 to 83 (an example of at least two distribution flow paths) positioned above the main flow path 80 and having first to third fuel gas inlets 45 to 47 at their lower ends that communicate with the main flow path 80, and branching the fuel gas to each of a plurality of groups of nozzles 30 with different numbers of sets of nozzles 30, and first to third solenoid valves 51 to 53 (an example of solenoid valves) that can open and close the first to third inlets 45 to 47. The combustion device 3 can switch the number of burners burning by switching the supply of fuel gas to the first to third distribution channels 81 to 83 by opening and closing the first to third inlets 45 to 47 using the first to third solenoid valves 51 to 53. In the gas distribution unit 7, the first distribution channel 81 (an example of at least one distribution channel), which has more sets of nozzles 30 than the second and third distribution channels 82, 83 (an example of other distribution channels), includes a first introduction section 36 (an example of an introduction section) whose channel width widens as it extends upward from the first inlet 45, and a first distribution section 39 (an example of a distribution section) in which sets of nozzles 30 are arranged in the left-right direction and communicate with the upper end of the first introduction section 36. The right end of the first distribution section 39 (an example of one end on the left or right side) is positioned to protrude to the right of directly above the first inlet 45. Then, the right side edge of the first introduction section 36 becomes tangent to the first inlet 45 in a front view and connects to the outer circumference of the nozzle 30B at the end of the first distribution section 39 (an example of the outermost left and right positions) with a virtual straight line L on the right side. R The first introduction section 36 has an overhang 65 that extends towards the center of the first introduction section 36 (an example of a virtual straight line), and the upper edge 68 of the overhang 65 extends to the left (an example of the other left or right side) below the row of lower nozzles 30C and 30D, which includes nozzle 30B. With this configuration, the protruding portion 65 can guide fuel gas into the end of the first distribution portion 39, thereby generating a vortex. Therefore, fuel gas can be supplied evenly to each nozzle 30 even at the end of the first distribution portion 39 that protrudes to the right of the first inlet 45.
[0027] The end of the first distribution section 39 is partitioned into a fifth region E5 (an example of a region) containing multiple sets of nozzles 30 by a partition wall 42A formed downward from the upper edge of the first distribution section 39. The lower end of the partition wall 42A is located between the upper and lower two-tiered nozzles 30, 30, and a fuel gas inlet 70 for the fifth region E5 is formed between the lower end of the partition wall 42A and the corner 69 of the upper edge 68. Therefore, the fifth region E5 can be semi-sealed, and the fuel gas can be reliably guided into the fifth region E5 to form a vortex. The upper edge 68 is located below the fifth region E5, and the left corner 69 of the upper edge 68 (an example of the other end on the left or right side) is positioned at 60% of the left-right length of the fifth region E5. Therefore, by ensuring a sufficient width for the inlet 70 into which fuel gas can flow into the fifth region E5, it is possible to reliably form vortices within the fifth region E5.
[0028] Next, we will explain examples of changes to the disclosure related to the protruding portion. The end of the upper edge is not limited to a position that is 60% of the area of the distribution section's end. However, if the length of the upper edge is too short, it becomes difficult for vortices to form within the area, so it is desirable to position the end of the upper edge at a position that is at least 50% of the area. Also, if the length of the upper edge is too long, the inlet becomes narrow and it becomes difficult for fuel gas to flow into the area, so it is desirable to position the end of the upper edge at a position that is 75% or less of the area. The front view shape of the protruding portion can be modified as appropriate. For example, the lower edge may be formed in a straight line without bulging, or the lower edge and middle edge may be formed in a continuous curved shape. The number of nozzle sets within the area can be changed as needed. The shape of the partition walls can be changed as needed. Screw fastening is not required. Partition walls can also be omitted. In the above configuration, an overhang is formed on the right side edge of the inlet; however, depending on the position of the distribution channel and the direction of fuel gas inflow from the inlet, an overhang may be formed on the left side edge of the inlet. The side surfaces of the main flow path may be formed in a vertical direction rather than being inclined. In the disclosure relating to the protruding portion, disclosure relating to the flow-dividing projection and / or disclosure relating to the partition wall with extension portion may be omitted.
[0029] (Effects of disclosure regarding partition walls with extensions) The combustion device 3 in the water heater 1 of the above configuration includes an inner case 6 that houses a plurality of burners, a plurality of sets of nozzles 30 assembled in the inner case 6 and arranged in the left-right direction as upper and lower two-tiered sets that inject fuel gas to each burner, a main flow path 80 into which fuel gas is introduced and extends in the left-right direction, first to third distribution flow paths 81 to 83 (an example of at least two distribution flow paths) positioned above the main flow path 80 and having first to third fuel gas inlets 45 to 47 at their lower ends that communicate with the main flow path 80, and branching the fuel gas to each of a plurality of groups of nozzles 30 with different numbers of sets of nozzles 30, first to third valve chambers 48 to 50 (an example of a plurality of valve chambers) that communicate with the first to third inlets 45 to 47, and first to third solenoid valves 51 to 53 provided in the first to third valve chambers 48 to 50 that can open and close the first to third inlets 45 to 47, respectively, and a gas distribution unit 7. The combustion device 3 can switch the number of burners burning by switching the supply of fuel gas to the first to third distribution channels 81 to 83 by opening and closing the first to third inlets 45 to 47 using the first to third solenoid valves 51 to 53. In the gas distribution unit 7, the first distribution channel 81 (an example of one distribution channel), which has more sets of nozzles 30 than the second and third distribution channels 82, 83 (an example of other distribution channels), is in communication with the left end of the main channel 80 (an example of either the left or right end) via the first inlet 45. It includes a first introduction section 36 (an example of an introduction section) where the channel width widens as it extends upward from the first inlet 45, and a first distribution section 39 (an example of a distribution section) where sets of nozzles 30 are arranged in the left-right direction and are in communication with the upper end of the first introduction section 36. The first distribution section 39 has a partition wall 42 that extends downward from the upper end of the first distribution section 39 to the space between the upper and lower rows of nozzles 30, dividing the rows of nozzles 30 in the left-right direction into multiple rows.
[0030] On the other hand, the main flow path 80 has an upper surface portion 56 that extends in the left-right direction, and a left side surface portion 57 (an example of a side surface portion) that slopes downward from the upper end away from the right end (an example of the other left or right end), and a first opening 54 (an example of an opening) that communicates with the first valve chamber 48 is provided at the corner between the upper surface portion 56 and the left side surface portion 57. Furthermore, when a third virtual line L3 is extended toward the first introduction section 36 and the first distribution section 39, passing through the intersection of a first virtual line L1 extending horizontally along the upper surface 56 in a front view and a second virtual line L2 extending vertically inclined along the left side surface 57 in a front view, and bisecting the angle α between the first virtual line L1 and the second virtual line L2, an extension 71 is formed on one partition wall 42B approaching the third virtual line L3, extending downward to the height of the lower nozzle 30. In this configuration, the main flow of fuel gas from the first inlet 45 to the left side of the first introduction section 36 collides with the partition wall 42B and splits into left and right sections, which are then guided to the right side of the first introduction section 36 and the first distribution section 39. Therefore, the uneven flow of fuel gas in the large area of the first distribution channel 81 is reduced, and fuel gas can be supplied evenly to each nozzle 30.
[0031] Next, we will explain examples of changes to the disclosure related to partition walls with extensions. In the above configuration, the extension of the partition wall extends to the height of the lower nozzle, but the extension may extend beyond the lower nozzle downwards. In the above configuration, the extension is provided on the partition wall to which the third virtual line approaches, but the extension may also be provided on the partition wall to which the third virtual line intersects. The extension is not limited to a shape that extends linearly from the partition wall as in the above configuration. The extension may be wider or narrower than the partition wall. The extension may not be linear, but may be bent toward a third imaginary straight line. In disclosure relating to a partition wall with an extension, disclosure relating to the flow-dividing projection and / or the overhanging portion may be omitted.
[0032] Next, we will explain some examples of changes common to each disclosure. The number of nozzles is not limited to the above configuration and can be increased or decreased as appropriate. The number of distribution channels can also be increased or decreased as appropriate. In the above configuration, the second distribution channel and the third distribution channel are connected by a connecting channel, but the connecting channel may be eliminated and the second distribution channel and the third distribution channel may be formed independently. The configuration of the main flow path and each distribution flow path is not limited to the configuration described above. For example, the gas inlet of the main flow path may be arranged in reverse order. The configuration of the water heater itself is not limited to the above forms. For example, the disclosures are applicable to types that have a secondary heat exchanger to recover latent heat, types with an exhaust pipe that protrudes upward, and types that have a bath circuit or heating circuit installed. [Explanation of Symbols]
[0033] 1. Water heater, 2. Housing, 3. Combustion device, 4. Heat exchanger, 5. Exhaust section, 6. Inner case, 7. Gas distribution unit, 9. Controller, 11. Water supply pipe, 12. Hot water outlet pipe, 16. Gas proportional valve unit, 25. Main body, 26. Cover, 27. Seal, 28. Main recess, 29. Gas inlet, 30. Nozzle 31...Outer frame, 32...Partition frame, 33...First recess, 34...Second recess, 35...Third recess, 36...First inlet, 37...Second inlet, 38...Third inlet, 39...First distribution section, 40...Second distribution section, 41...Third distribution section, 42...Partition wall, 45...First inlet, 46...Second inlet, 47...Third inlet, 48...First valve chamber, 4 9...Second valve chamber, 50...Third valve chamber, 51...First solenoid valve, 52...Second solenoid valve, 53...Third solenoid valve, 54...First opening, 55...Second opening, 56...Upper surface, 57...Left side surface, 58...Third opening, 59...Connecting passage, 60...Diversion projection, 65...Protruding part, 66...Lower edge, 67...Middle edge, 68...Upper edge, 69...Corner, 70 ··Inlet, 71··Extension, 80··Main channel, 81··First distribution channel, 82··Second distribution channel, 83··Third distribution channel, E1~E5··First to fifth regions, O1~O3··Centers of the first to third inlets, α··Angle formed between the top surface and the left side surface, L1··First virtual straight line, L2··Second virtual straight line, L3··Third virtual straight line.
Claims
1. An inner case that accommodates multiple burners, Assembled into the aforementioned inner case, A gas distribution unit comprising: multiple sets of nozzles arranged in the left-right direction as upper and lower tiers and each injecting fuel gas to the respective burner; a main flow path into which fuel gas is introduced and extends in the left-right direction; at least two distribution flow paths positioned above the main flow path and having a fuel gas inlet at its lower end that communicates with the main flow path, each branching the fuel gas to multiple groups of nozzles with different numbers of nozzle sets; multiple valve chambers communicating with each of the inlets; and solenoid valves provided in each of the valve chambers that can open and close each of the inlets, respectively. A combustion device in which the number of burners can be switched by switching the supply of fuel gas to each distribution channel by opening and closing each of the inlets by each of the solenoid valves, In the aforementioned gas distribution unit, One distribution channel with a larger number of nozzle sets than the other distribution channels is connected to either the left or right end of the main channel via the inlet and includes an introduction section in which the width of the channel widens as it extends upward from the inlet, and a distribution section in which the nozzle sets are arranged in the left-right direction and are connected to the upper end of the introduction section, and the distribution section has a partition wall that extends downward from the upper end of the distribution section to at least between two upper and lower rows of nozzles, dividing the rows of nozzles in the left-right direction into multiple rows, The main flow path has an upper surface portion extending in the left-right direction and side portions that slope downward from the upper end, moving away from the other left and right ends, and an opening communicating with the valve chamber is provided at the corner between the upper surface portion and the side portions. A combustion apparatus characterized in that, when a third virtual line is extended toward the introduction and distribution sections, passing through the intersection of a first virtual line extending horizontally along the upper surface in a front view and a second virtual line extending inclined vertically along the side surface in a front view, and bisecting the angle between the first virtual line and the second virtual line, one of the partition walls that intersects with or is closest to the third virtual line has an extension formed thereon that extends downward to at least the height of the lower nozzle.
2. A water heater comprising a combustion device as described in claim 1 and a heat exchanger through which the combustion exhaust of the burner of the combustion device passes, wherein hot water can be supplied by heat exchange between water passing through the heat exchanger and the combustion exhaust of the burner.