Method for manufacturing a water heater and method for determining the position of a partition

Abstract

To provide a method of producing a water heater capable of preventing a burner unit from being scorched by a flame of the burner unit, and a method of determining the position of a partition part.SOLUTION: Cooling spaces 91, 92 are each respectively disposed between outer burner units 51, 51 each respectively positioned on either of the left and right sides of a unit group 23, and each of a right wall 31 and a left wall 32, to allow the combustion air to flow from below to above. Partition walls 425, 435 are each disposed in a specified region in the swirl flows of the combustion air each generated in the cooling spaces 91, 92 respectively. The specified region is a region determined by a simulation for the combustion air to flow downward therein. The partition walls 425, 435 each partition the cooling spaces 91, 92 respectively, in the front and rear direction. Thereby, the downward flows are each divided by the partition walls 425, 435 respectively in the front and rear direction to weaken the downward flows. Hence, the upward flows of the combustion air become dominant to suppress the generation of swirl flows in the cooling spaces 91, 92.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a method for manufacturing a water heater and a method for determining the position of a partition portion. [Background technology]

[0002] The water heater described in Patent Document 1 has a combustion device and a heat exchanger inside a housing. The combustion device has a group of units and an inner case. The group of units has multiple burner units arranged side by side in the left-right direction, and ignites and burns a mixture of gas and combustion air. The inner case houses the group of units inside. The heat exchanger is located above the combustion device and heats the water passing through it with the combustion exhaust from the group of units.

[0003] An opening is provided on the underside of the inner case. The opening takes in combustion air blown in by the fan. A support plate and a lower plate are assembled inside the inner case. The support plate is U-shaped when viewed from above and supports the group of units inside. The lower plate divides the space inside the inner case into upper and lower sections and is positioned below the group of units. A plurality of small holes are provided in the lower plate. The plurality of small holes supply combustion air to the multiple burner units arranged side by side in the left-right direction. A front plate extending upward is provided at the front end of the lower plate. The front plate is positioned in front of the group of units and supports the fronts of each of the multiple burner units.

[0004] Cooling spaces are provided between the inner surfaces of the left and right side walls of the inner case and the left and right burner units of the unit group. The cooling spaces branch a portion of the combustion air taken into the inner case from the opening to the left and right sides of the unit group, passing it from below to above as cooling air to prevent overheating of the combustion device. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-80613 Summary of the Invention [Problem to be solved by the invention]

[0006] In the combustion device with the above configuration, there was a problem of partial burning of the burner units on both the left and right sides of the unit group. Investigation into the cause of this problem revealed that in the cooling space, the front plate imparts a backward vector to the air flowing from below to above, causing it to flow downward at the rear of the cooling space, creating a vortex. It is believed that the downward flow of this vortex pushes the flames of the burner units on both the left and right sides of the unit group downward, resulting in the burning of both the left and right burner units.

[0007] An object of the present invention is to provide a method for manufacturing a water heater and a method for determining the position of a partition section that can prevent the burner unit from being burned by the flame of the burner unit. [Means for solving the problem]

[0008] The method for manufacturing a water heater according to claim 1 includes a unit group in which a plurality of burner units are arranged side by side in the left-right direction, a rear wall portion, a pair of left and right side wall portions extending forward from both left and right ends of the rear wall portion, a bottom wall portion connected to the rear wall portion and the pair of left and right side wall portions and closing the lower surface, an inner case that houses the unit group inside, and an opening that is provided in the bottom wall portion for taking in air supplied from a fan provided below the bottom wall portion, support portions that are provided inside the inner case and support the unit group so as to sandwich it from the front and rear directions, and a method for manufacturing the water heater according to claim 1, the method including the steps of: A method for manufacturing a water heater comprising: outer burner units located on both the left and right sides of a burner unit; and a cooling space provided between each of the pair of left and right side wall portions, to which the air taken into the inner case through the opening is supplied, the method comprising a first step of identifying, through testing or experimentation, the downward flowing region of the vortex flow including the upward and downward flows of the air generated in the cooling space; and a second step of dividing the cooling space in the front-to-back direction within the region identified in the first step and providing a partition wall that separates the downward flow.

[0009] In the method for manufacturing a water heater according to claim 2, the test or experiment may be a test or experiment in which a flow velocity of combustion air is measured using a sensor while the water heater is in operation.

[0010] In the method for manufacturing a water heater according to claim 3, the test or experiment may be a test or experiment in which a model of the water heater is constructed on a computer and a simulation is performed using the model.

[0011] The method for determining the position of a partition part according to claim 4 includes a unit group including a plurality of burner units arranged side by side in the left-right direction, a rear wall part, a pair of left and right side wall parts extending forward from both left and right ends of the rear wall part, a bottom wall part connected to the rear wall part and the pair of left and right side wall parts to close the lower surface, an inner case which houses the unit group inside and which has an opening for taking in air supplied from a fan provided below the bottom wall part, support parts which are provided inside the inner case and support the unit group so as to sandwich it from the front and rear directions, and outer burner parts located on both left and right sides of the plurality of burner units of the unit group. A method for determining the position of a partition within a cooling space of a water heater comprising: a cooling space provided between an inner unit and each of the pair of left and right side wall portions, to which the air taken into the inner case through the opening is supplied; and a partition provided within the cooling space to divide the cooling space in the front-to-rear direction, the method comprising: a step of identifying, by test or experiment, the downward flowing region of a vortex including upward and downward flows of the air generated within the cooling space; and a step of determining the position of the partition within the region identified in the identification step.

[0012] In the method for determining the position of a partition part according to claim 5, the test or experiment may be a test or experiment in which a flow velocity of combustion air is measured using a sensor while the water heater is in operation.

[0013] In the method for determining the position of a partition part according to claim 6, the test or experiment may be a test or experiment in which a model of the water heater is constructed on a computer and a simulation is performed using the model. [Effects of the Invention]

[0014] According to the water heater manufacturing method of claim 1, a partition is placed in a region of the cooling space identified by test or experiment results as a region where a downward flow occurs. While some air from the fan simultaneously flows into the region where a downward flow occurs, without the partition, the downward vector of the vortex flow is relatively stronger than the upward vector of the air flowing in from below, resulting in a downward flow. By placing a partition in such a region, the downward flow can be reliably separated in the front-to-rear direction. This weakens the downward flow, preventing the flame of the burner unit from being directed downward. Therefore, a water heater manufactured by the manufacturing method of the present invention can prevent the burner unit from being burned by the flame of the burner unit. [Brief explanation of the drawings]

[0015] [Figure 1] FIG. 1 is a perspective view of a water heater 1. [Figure 2] FIG. 2 is a perspective view of the combustion device 3. [Figure 3] FIG. 2 is a plan view of the combustion device 3. [Figure 4] FIG. 2 is an exploded perspective view of the combustion device 3. [Figure 5] FIG. 2 is a cross-sectional perspective view of the combustion device 3 with a part of the right side broken away. [Figure 6] FIG. 10 is a diagram showing a simulation of the air flow velocity when there is no partition wall in the cooling space 92. [Figure 7] 10 is a diagram showing a simulation of the air flow velocity when a partition wall 435 is placed in the cooling space 92. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0016] Hereinafter, an embodiment of the present invention will be described. The device configurations described below are merely illustrative examples and are not intended to be limiting unless otherwise specified. The drawings are used to explain technical features that can be adopted by the present invention.

[0017] The configuration of water heater 1 will be described with reference to Figure 1. Water heater 1 includes a combustion device 3, a heat exchanger 4, and an exhaust hood 5, installed in this order from bottom to top within a rectangular box-shaped housing 2. A gas supply unit 6 is attached to the front of the combustion device 3. The gas supply unit 6 distributes and supplies gas to a group of units 23 (described below) within the combustion device 3. A fan 7 is attached to the underside of the combustion device 3. The fan 7 supplies combustion air to the combustion device 3. A controller 8 containing an electrical circuit board is installed horizontally on the inner bottom surface of the housing 2, in front of the fan 7 and below the combustion device 3. The heat exchanger 4 has multiple fins (not shown) inside the casing at predetermined intervals in the left-right direction, and a heat transfer tube 9 that runs through each fin in a serpentine pattern. Heat is exchanged between the combustion exhaust air passing between the fins from below and the water flowing through the heat transfer tube 9. The exhaust hood 5 has a horizontally elongated exhaust pipe 10 on its front. The exhaust pipe 10 penetrates a front cover (not shown) and protrudes forward, and discharges the combustion exhaust gas that has passed through the heat exchanger 4 to the outside.

[0018] A gas inlet 11, a water inlet 12, and a hot water outlet 13 are provided on the underside of the casing 2. An external gas pipe (not shown) is connected to the gas inlet 11. A water pipe (not shown) is connected to the water inlet 12. A piping (not shown) to a hot water tap is connected to the hot water outlet 13. The gas inlet 11 is connected to the gas supply unit 6 within the casing 2 via a gas pipe 14 equipped with a main valve, a proportional valve, etc. The water inlet 12 is connected to the upstream end of the heat transfer pipe 9 of the heat exchanger 4 via a water supply pipe 15. The hot water outlet 13 is connected to the downstream end of the heat transfer pipe 9 via a hot water outlet pipe 16.

[0019] The structure of the combustion device 3 will be described with reference to Figures 2 to 4. The combustion device 3 includes an inner case 20 shaped like a square box. The inner case 20 is housed in the housing 2. A unit group 23 is assembled inside the inner case 20. The unit group 23 has a plurality of flat burner units 51 stacked in the left-right direction and has a substantially rectangular parallelepiped shape. The inner case 20 includes a case body 21 and a front wall 25, and is made of metal (e.g., aluminum-plated steel plate). The case body 21 is open at the top and front. The front wall 25 is assembled to the front of the case body 21. The unit group 23 is fixed to the inside of the case body 21 via front and rear inner plates 24 and support plates 22.

[0020] The case body 21 includes a right wall 31, a left wall 32, a rear wall 33, a bottom wall 34, and an overheat protection plate 38. A raised portion 36 is formed by bending upward along the entire length of the upper end of the rear wall 33 and the upper ends of the right wall 31 and left wall 32. The raised portion 36 has a generally L-shaped cross section. Each raised portion 36 is provided with a plurality of crimping pieces 37 spaced apart at predetermined intervals. Fixing pieces 311, 321 are formed by bending outward at the front ends of the right wall 31 and the left wall 32, respectively. The front wall 25 and the gas supply unit 6 are screwed to the fixing pieces 311, 321. The bottom wall 34 is provided with an opening 35 to which the fan 7 is connected. The overheat protection plate 38 is a horizontally elongated rectangular metal plate (e.g., a stainless steel plate) that covers the upper portion of the inner surface of the rear wall 33 and is attached with a gap. A bulge 331 is provided on the rear wall 33 below the overheat protection plate 38 and protrudes rearward. The bulge 331 has a horizontally elongated rectangular shape that extends in the left-right direction.

[0021] The support plate 22 includes a back plate portion 40, a right plate portion 42, and a left plate portion 43, and is formed in a generally U-shape in a plan view that opens forward. The back plate portion 40 has a horizontally elongated rectangular shape in a front view and is provided along the inner surface of the rear wall portion 33. The right plate portion 42 and the left plate portion 43 are bent forward from the right and left ends of the back plate portion 40. A fitting portion 44 protrudes rearward from the back plate portion 40. The fitting portion 44 has the same shape as the bulge portion 41 and fits into the bulge portion 41 from the front. A plurality of support pieces 45 are formed on the upper edge of the back plate portion 40 by being bent forward at equal intervals in the left-right direction. Slits 45A are formed between each support piece 45 on the upper edge of the back plate portion 40. The slits 45A are downward cuts. A plurality of support pieces 46 are also formed on the lower edge of the back plate portion 40 by being bent forward at equal intervals in the left-right direction. The plurality of support pieces 45, 46 are engaged between each of the burner units 51 of the unit group 23.

[0022] The right plate portion 42 and the left plate portion 43 have a width sufficient to accommodate the unit group 23, and extend forward inside the right wall portion 31 and the left wall portion 32. The right plate portion 42 is provided with, in order from the rear side to the front side, an extension portion 421, a step portion 422, and an abutment portion 423. The extension portion 421 extends forward from the right end portion of the back plate portion 40 to a position corresponding to the front side of the unit group 23. The step portion 422 is bent rightward from the front end portion of the extension portion 421 and extends rightward. The abutment portion 423 is bent forward from the right end portion of the step portion 422 and extends forward, abutting against the inner surface of the right wall portion 31. Like the right plate portion 42, the left plate portion 43 is provided with, in order from the rear side to the front side, an extension portion 431, a step portion 432, and an abutment portion 433. The extension portion 431 also extends forward from the left end of the back plate portion 40 to a position corresponding to the front side of the unit group 23. The step portion 432 is bent leftward from the front end of the extension portion 431 and extends leftward. The abutment portion 433 is bent forward from the left end of the step portion 432 and extends forward, abutting against the inner surface of the left wall portion 32. Mounting pieces 47, 48 having screw holes 471, 481 are formed by being bent inward at the front ends of the right plate portion 42 and the left plate portion 43, respectively.

[0023] A partition wall 425 is provided at approximately the middle in the front-to-rear direction on the right surface of the extension portion 421 of the right plate portion 42. The partition wall 425 protrudes to the right and is formed in a generally rectangular shape that is long in the vertical direction when viewed from the front. The right end of the partition wall 425 contacts the inner surface of the right wall portion 31 (see FIGS. 3 and 4). A partition wall 435 is also provided at approximately the middle in the front-to-rear direction on the left surface of the extension portion 431 of the left plate portion 43. The partition wall 435 protrudes to the left and is formed in a generally rectangular shape that is long in the vertical direction when viewed from the front. The left end of the partition wall 435 contacts the inner surface of the left wall portion 32 (see FIG. 3). The partition walls 425, 435 may be fixed to the right surface of the extension portion 421 and the left surface of the extension portion 431, respectively, by screws, welding, or the like.

[0024] The support plate 22 is attached to the rear wall 33 with rivets (not shown) at a position where the fitting portions 44 fit into the bulges 331. The upper portion of the support plate 22 overlaps the lower portion of the overheat protection plate 38 from the front, and presses and fixes the lower portion of the overheat protection plate 38 toward the rear wall 33. Each slit 45A in the support plate 22 extends downward beyond the lower end of the overheat protection plate 38 and communicates with a gap that occurs between the inner surface of the rear wall 33 and the overheat protection plate 38.

[0025] Each burner unit 51 in the unit group 23 is a well-known rich-lean burner. The burner unit 51 is equipped with a lean-side inlet 53, a rich-side inlet 54, a mixing section 55, and a burner port section 56. The lean-side inlet 53 is a lower opening that opens forward and introduces fuel gas and primary air, while the rich-side inlet 54 is an upper opening. The mixing section 55 is located downstream of the lean-side inlet 53 and the rich-side inlet 54, and its interior is separated for each inlet. The burner port section 56 opens at the upper end of the mixing section 55 and consists of a central lean-side inlet and rich-side inlets on either side of it.

[0026] The inner plate 24 has a lower plate portion 61 and a front plate portion 62, and is generally L-shaped in a side view. The lower plate portion 61 is located below the unit group 23. The front plate portion 62 is located in front of the unit group 23. A plurality of small holes 611 are formed in the lower plate portion 61 at predetermined intervals in the front-rear and left-right directions. A screw fastening piece 612 is formed by bending it downward at the rear end of the lower plate portion 61. The screw fastening piece 612 is fastened to the rear wall portion 33 from the front by two screws 81, 82 on the left and right. Lower bent pieces 63, 64 are formed downward at the right and left end edges of the lower plate portion 61. The lower bent pieces 63, 64 abut against the inner surfaces of the right wall portion 31 and the left wall portion 32, respectively.

[0027] A plurality of support pieces 65 are formed at the upper edge of the front plate portion 62 at equal intervals in the left-right direction and are bent rearward. The support pieces 65 engage between the burner units 51 of the unit group 23. As a result, the unit group 23 is sandwiched and supported between the front plate portion 62 of the inner plate 24 and the back plate portion 40 of the support plate 22. Therefore, the combustion device 3 can stably support the unit group 23 by sandwiching it from the front and rear directions.

[0028] Below the multiple support pieces 65, multiple pairs of upper and lower lean gas supply holes 66 and rich gas supply holes 67 are arranged in parallel in the left-right direction. The lower lean gas supply hole 66 is an oval burring hole and corresponds to the lean side inlet 53 of each burner unit 51. The upper rich gas supply hole 67 is a circular burring hole and corresponds to the rich side inlet 54 of each burner unit 51. This allows the combustion device 3 to supply gas to each of the multiple burner units 51 through the multiple lean gas supply holes 66 and rich gas supply holes 67. In addition, front bent pieces 68, 69 are formed at the right and left ends of the front plate portion 62 facing forward. The front bent pieces 68, 69 abut against the inner surfaces of the right wall portion 31 and the left wall portion 32, respectively. Fixing holes 623, 624 are formed at the middle of the height direction on the right and left ends of the front plate portion 62. Inside the front bent pieces 68 and 69, the mounting pieces 47, 48 of the support plate 22 abut against the back surface of the front plate portion 62, and screws 83, 84 are fastened from the front into the screw holes 471, 481 of the mounting pieces 47, 48 via the fixing holes 623, 624.

[0029] The front wall 25 has a horizontally elongated rectangular shape that covers the upper half of the front surface of the case body 21. A raised portion 74 is provided on the upper edge of the front wall 25. The raised portion 74 is bent upward along the entire length of the upper edge of the front wall 25 and has a generally L-shaped cross section. A plurality of crimping pieces 75 are provided in the raised portion 74 at predetermined intervals in the left-right direction. A mounting hole 71, a mounting hole 72, and a through-hole 73 are provided at predetermined intervals in the middle of the height direction of the front wall 25, from right to left in this order. A discharge electrode (not shown) for ignition is attached to the mounting hole 71. A flame rod (not shown) serving as a flame detection electrode is attached to the mounting hole 72. A sight glass (not shown) is attached opposite the through-hole 73. The front wall 25 having the above-mentioned shape is fixed to the front plate portion 62 of the inner plate 24 from the front with a screw 89, and is also fixed to the fixing pieces 311, 312 of the case body 21 from the front with screws 87, 88.

[0030] As shown in FIG. 3 , cooling spaces 91, 92 are provided inside the inner case 20 between the burner units 51, 51 located on both the left and right sides of the unit group 23 and the inner surfaces of the right wall portion 31 and left wall portion 32 of the case body 21. The cooling spaces 91, 92 prevent overheating of the unit group 23 by allowing primary combustion air taken into the inner case 20 from the opening 35 in the bottom wall portion 34 to pass from bottom to top as cooling air. A partition wall 425 is disposed at the rear of the right cooling space 91 (see FIG. 5 ). The partition wall 425 divides the cooling space 91 into front-rear sections. A partition wall 435 is disposed at the rear of the left cooling space 92. The partition wall 435 divides the cooling space 92 into front-rear sections. The specific positions and functions of the partition walls 425, 435 will be described later.

[0031] 2 to 7, the vortex flow of cooling air generated in cooling spaces 91, 92 will be explained. FIG. 6 is an analytical diagram simulating the air flow velocity when there is no partition wall 435 in cooling space 92 while the water heater 1 is operating. FIG. 7 is an analytical diagram simulating the air flow velocity when there is a partition wall 435 in cooling space 92 while the water heater 1 is operating. The darker the color, the higher the air flow velocity (Velocity [K] (m / s)). The thick white arrows in FIGS. 6 and 7 indicate the air flow. The simulation results for cooling space 91 are almost the same as those for cooling space 92, so they will be omitted.

[0032] As shown in Figures 2 and 3, air blown upward from the fan 7 flows into the inner case 20 through the opening 35 in the bottom wall portion 34. The flow of the flowing air is rectified by a plurality of small holes 611 provided in the lower plate portion 61 of the inner plate 24 and supplied as secondary air to the unit group 23 side. This improves the combustion efficiency at each of the burner port portions 56 of the plurality of burner units 51. Meanwhile, the remaining air branches off to the left and right sides of the lower plate portion 61, is deflected upward by the right wall portion 31 and left wall portion 32 of the case body 21, and flows into the cooling spaces 91, 92. The air flows upward through the cooling spaces 91, 92 as cooling air.

[0033] As shown in the experimental results in FIG. 6, when the partition wall 435 is not provided within the cooling space 92, a vortex of cooling air is generated within the cooling space 92. The vortex is a flow of air that rises at the front and descends at the rear. Specifically, when air flows into the inner case 20 through the opening 35 provided at the rear of the bottom wall 34, the air rises while diffusing forward within the cooling space 92 (see (1) in FIG. 6). At this time, the air is deflected by the front plate portion 62 of the inner plate 24, imparting a backward vector (see (2) in FIG. 6). Then, a portion of the cooling air deflected backward comes into contact with the rear wall portion 33 of the case body 21 and flows downward (see (3) in FIG. 6). At the same time, a portion of the air from the fan 7 flows upward through the opening 35 in the bottom wall 34 into the region P where a downward flow is suspected to be occurring.

[0034] Here, in region P, the downward vector of the air is relatively stronger than the upward vector of the air flowing in from openings 35 in bottom wall portion 34. Therefore, the downward flow is dominant in region P, and it is presumed that a vortex flow as shown in Fig. 6 is generated. The downward flow caused by the vortex flow pushes the flames of burner units 51 located on both the left and right sides of unit group 23 downward, which may cause the sides of burner units 51 to be scorched and burnt.

[0035] Therefore, in the combustion device 3 of this embodiment, partition walls 425, 435 are disposed in the region P where the downward airflow occurs in each of the cooling spaces 91, 92. The partition walls 425, 435 divide the cooling spaces 91, 92 in the front-rear direction. As a result, as shown in the experimental results of FIG. 7 , the downward airflow in the region P is divided into front and rear by the partition wall 435, making the downward airflow relatively weak. Therefore, the downward airflow is overwhelmed by the upward airflow flowing in from the opening 35 in the bottom wall portion 34, and as a result, tends to rise. As a result, the combustion device 3 can effectively suppress the generation of vortexes in the cooling spaces 91, 92, and can prevent the burner units 51 on both the left and right sides of the unit group 23 from being burned by their own flames and causing burns.

[0036] As described above, the water heater 1 manufactured by the manufacturing method of this embodiment includes the unit group 23, inner case 20, support plate 22, inner plate 24, cooling spaces 91, 92, and partition walls 425, 435. The unit group 23 is configured by arranging multiple burner units 51 side by side in the left-right direction. The inner case 20 includes a right wall portion 31, a left wall portion 32, a rear wall portion 33, a bottom wall portion 34, and an opening 35, and houses the unit group 23 inside. The right wall portion 31 and the left wall portion 32 extend forward from the right and left ends of the rear wall portion 33. The bottom wall portion 34 is connected to the right wall portion 31, the left wall portion 32, and the rear wall portion 33, respectively, and closes the lower surface. The opening 35 is provided in the bottom wall portion 34 and takes in combustion air supplied from the fan 7 provided below the bottom wall portion 34. The support plate 22 and inner plate 24 are provided inside the inner case 20 and support the unit group 23 by sandwiching it from the front to the back. The cooling spaces 91, 92 are provided between the outer burner units 51, 51 located on both the left and right sides of the multiple burner units 51 of the unit group 23 and the right wall portion 31 and the left wall portion 32, respectively, and allow combustion air taken into the inner case 20 from the opening 35 to pass from bottom to top. The partition walls 425, 435 are provided within region P of the vortex of combustion air generated in the cooling spaces 91, 92. Region P is the region where the combustion air flows downward, as identified by simulation. The partition walls 425, 435 divide the cooling spaces 91, 92 in the front to back direction.

[0037] At the same time, a portion of the combustion air from fan 7 flows into region P where the downward flow is occurring. By disposing partition walls 425, 435 in region P, the downward flow is divided in the front-to-rear direction by partition walls 425, 435. This weakens the downward flow and makes the upward flow of combustion air dominant, effectively suppressing the generation of vortexes. Therefore, water heater 1 can prevent burner unit 51 in combustion device 3 from being burned by the flame of burner unit 51.

[0038] In the above description, the right wall portion 31 and the left wall portion 32 of the inner case 20 are an example of a "pair of left and right side wall portions" of the present invention. The opening 35 is an example of an "opening" of the present invention. The support plate 22 and the inner plate 24 are an example of a "support portion" of the present invention. The partition walls 425, 435 are an example of a "partition portion" of the present invention. The burner unit 51 is an example of a "burner" of the present invention.

[0039] The present invention is not limited to the above embodiment, and various modifications are possible. In the above embodiment, the partition walls 425, 435 are arranged in the predetermined region P in the cooling spaces 91, 92 by fixing the partition walls 425, 435 to the right plate portion 42 and the left plate portion 43 of the support plate 22. However, the partition walls may be provided on a member other than the support plate 22, and may be provided on the inner surfaces of the right wall portion 31 and the left wall portion 32 of the inner case 20, for example.

[0040] In the above embodiment, the unit group 23 is supported by being sandwiched from the front and rear between the back plate portion 40 of the support plate 22 and the front plate portion 62 of the inner plate 24, but other methods of support are also possible, and for example, the direction, position, and structure in which the unit group 23 is supported can be freely changed. It is desirable to provide cooling spaces 91, 92 on both the left and right sides of the unit group 23.

[0041] The position and shape of opening 35 in bottom wall portion 34 are not limited to those in the above embodiment. Although there is one opening 35, multiple openings may be provided. Since the flow of cooling air in cooling spaces 91, 92 changes depending on the position, shape, size, number, etc. of opening 35, it is advisable to check the occurrence of vortex flow and the position of area P for each water heater and adjust the positions of partition walls 425, 435.

[0042] Although the partition walls 425, 435 are parallel to the left-right direction, there are no limitations on their shape as long as they can partition the cooling spaces 91, 92 in the front-rear direction within the region P. For example, they may be inclined with respect to the left-right direction. Furthermore, they do not have to be flat, and may be curved or bent.

[0043] The water heater 1 is a normal water heater equipped with one heat exchanger 4, but may also be a latent heat water heater equipped with two heat exchangers, one for recovering sensible heat and one for recovering latent heat. The inner plate 24 is generally L-shaped in side view, with the lower plate portion 61 and the front plate portion 62 integrated together, but they may also be separate bodies. [Explanation of symbols]

[0044] 1. Water heater 3 Combustion equipment 7 Fan 20 Inner case 22 Support plate 23 Unit Group 24 Inner plate 31 Right wall 32 Left wall 33 Rear wall 34 Bottom wall 35 Aperture 40 Back plate part 45 Support piece 51 Burner unit 61 Lower plate part 62 Front plate part 65 Support piece 66 Lean gas supply hole 67 Dense gas supply hole 91,92 Cooling space 425,435 Partition wall

Claims

1. a unit group including a plurality of burner units arranged side by side in the left-right direction; an inner case that houses the group of units and includes a rear wall portion, a pair of left and right side wall portions extending forward from both left and right ends of the rear wall portion, a bottom wall portion that is connected to the rear wall portion and the pair of left and right side wall portions and closes the bottom surface, and an opening that is provided in the bottom wall portion and that takes in air supplied from a fan provided below the bottom wall portion; a support portion provided inside the inner case and configured to support the unit group by sandwiching the unit group from the front and rear directions; cooling spaces provided between outer burner units located on both the left and right sides of the plurality of burner units of the unit group and the pair of left and right side wall portions, and into which the air taken into the inner case through the opening is supplied; A method for manufacturing a water heater comprising: a step of identifying, by test or experiment, a region of the vortex flow including the upward and downward flows of the air generated in the cooling space, where the region flows downward; an installation step of installing a partition wall in the region identified in the identification step, which partitions the cooling space in the front-rear direction and separates the downward flow; A method for manufacturing a water heater, comprising:

2. The test or experiment is a test or experiment in which the flow rate of combustion air is measured using a sensor while the water heater is in operation. A method for manufacturing the water heater according to claim 1.

3. The test or experiment involves constructing a model of the water heater on a computer and conducting a simulation using that model. A method for manufacturing the water heater according to claim 1.

4. a unit group including a plurality of burner units arranged side by side in the left-right direction; an inner case that houses the group of units and includes a rear wall portion, a pair of left and right side wall portions extending forward from both left and right ends of the rear wall portion, a bottom wall portion that is connected to the rear wall portion and the pair of left and right side wall portions and closes the bottom surface, and an opening that is provided in the bottom wall portion and that takes in air supplied from a fan provided below the bottom wall portion; a support portion provided inside the inner case and configured to support the unit group by sandwiching the unit group from the front and rear directions; cooling spaces provided between outer burner units located on both the left and right sides of the plurality of burner units of the unit group and the pair of left and right side wall portions, and into which the air taken into the inner case through the opening is supplied; a partition portion provided in the cooling space and dividing the cooling space in the front-rear direction; A method for determining the position of the partition in the cooling space of a water heater comprising: a step of identifying, by test or experiment, a region of the vortex flow including the upward and downward flows of the air generated in the cooling space, where the region flows downward; a determining step of determining a position of the partition within the region identified in the identifying step; A method for determining the position of a partition section, comprising:

5. The test or experiment is a test or experiment in which the flow rate of combustion air is measured using a sensor while the water heater is in operation.

5. The method for determining the position of a partition portion according to claim 4, wherein:

6. The test or experiment involves constructing a model of the water heater on a computer and conducting a simulation using that model.

5. The method for determining the position of a partition portion according to claim 4, wherein:

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