Heat exchanger and gas water heater

Abstract

The present application discloses a heat exchanger and a gas water heater. The heat exchanger comprises a housing, a plurality of heat exchange tubes, a plurality of first water boxes, two sets of cooling flow channels, and two second water boxes. The housing comprises a first side wall, a second side wall, a third side wall, and a fourth side wall. The plurality of heat exchange tubes are arranged in a heat exchange chamber, and two ends of each heat exchange tube respectively penetrate through the third side wall and the fourth side wall. Every two adjacent heat exchange tubes are in communication with each other via one first water box. A heat exchange flow channel is provided with a water inlet. The two sets of cooling flow channels are respectively arranged on the first side wall and the second side wall. The two second water boxes are respectively arranged on the third side wall and the fourth side wall. One of the second water boxes communicates the two sets of cooling flow channels with each other, and the other second water box is provided with a water outlet. A height dimension h1 of the first water boxes in a second direction and a height dimension h2 of the second water boxes in the second direction satisfy: h1 > h2.

Description

Heat exchangers and gas water heaters

[0001] Related applications

[0002] This application claims priority to Chinese patent application No. 202423186039.5, filed on December 23, 2024, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This application relates to the field of water heater technology, and in particular to a heat exchanger and a gas water heater. Background Technology

[0004] A gas water heater is a device that uses gas as fuel and heats cold water flowing through a heat exchanger to produce hot water.

[0005] In related technologies, the large local resistance at the bends connecting heat exchange tubes in heat exchangers leads to low heat exchange efficiency. Summary of the Invention

[0006] The main objective of this application is to propose a heat exchanger that aims to reduce local resistance and improve heat exchange efficiency.

[0007] To achieve the above objectives, the heat exchanger proposed in this application includes: a shell, a plurality of heat exchange tubes, a plurality of first water boxes, two sets of cooling flow channels, and two second water boxes.

[0008] In one embodiment of this application, the housing includes a first sidewall and a second sidewall opposite to each other along a first direction, and a third sidewall and a fourth sidewall opposite to each other along a second direction. The first sidewall, the fourth sidewall, the second sidewall, and the third sidewall are connected end to end to form a heat exchange chamber open at both ends in a third direction. The first direction, the second direction, and the third direction intersect each other.

[0009] In one embodiment of this application, a plurality of heat exchange tubes are disposed in the heat exchange chamber, and the two ends of the heat exchange tubes extend along a second direction to pass through the third side wall and the fourth side wall respectively.

[0010] In one embodiment of this application, a plurality of first water boxes are respectively disposed on the third side wall and the fourth side wall; each pair of adjacent heat exchange tubes are connected through a first water box, so that the plurality of heat exchange tubes are connected in series to form a heat exchange channel, and the heat exchange channel is provided with a water inlet.

[0011] In one embodiment of this application, two sets of cooling channels are respectively disposed on the first sidewall and the second sidewall, and are connected to the heat exchange channel.

[0012] In one embodiment of this application, two second water boxes are respectively disposed on the third side wall and the fourth side wall; one of the second water boxes connects the two sets of cooling channel groups, and the other second water box is provided with a water outlet.

[0013] In one embodiment of this application, the height dimension h1 of the first water box in the second direction and the height dimension h2 of the second water box in the second direction satisfy: h1>h2.

[0014] In one embodiment of this application, the height dimension h1 of the first water box in the second direction and the height dimension h2 of the second water box in the second direction satisfy: h1<3h2.

[0015] In one embodiment of this application, multiple first water boxes on the same sidewall are arranged independently of each other.

[0016] In one embodiment of this application, the first water box includes: a first bottom shell and a first cover shell.

[0017] In one embodiment of this application, the first bottom shell is provided with two first mounting holes, and two adjacent heat exchange tubes are respectively inserted into the two first mounting holes.

[0018] In one embodiment of this application, the first cover is disposed on the side of the first bottom shell away from the shell, and together with the first bottom shell, forms a first flow cavity, and the two adjacent heat exchange tubes are connected to the first flow cavity.

[0019] In one embodiment of this application, the first cover shell is welded and fixed to the first bottom shell.

[0020] In one embodiment of this application, the heat exchange tube is welded and fixed to the periphery of the corresponding first mounting hole.

[0021] In one embodiment of this application, the first bottom shell is welded and fixed to the corresponding third sidewall or the fourth sidewall.

[0022] In one embodiment of this application, the second water box extends along a first direction and is disposed on the corresponding third and fourth sidewalls.

[0023] In one embodiment of this application, the heat exchanger further includes two mounting plates disposed outside the third and fourth side walls, the mounting plates protruding outward in a direction away from the shell to form the second water box;

[0024] The first water box is located on the outside of the mounting plate, and the mounting plate has multiple first through holes for the heat exchange tubes to pass through.

[0025] In one embodiment of this application, each group of cooling channels includes at least two cooling pipes arranged in parallel along a third direction;

[0026] The heat exchanger also includes a third water box disposed on the third side wall or the fourth side wall, the third water box connecting the cooling channel assembly on the first side wall to one end of the heat exchange channel.

[0027] In one embodiment of this application, the third water box is set independently of the first water box.

[0028] In one embodiment of this application, the third water box includes a third bottom shell and a third cover shell.

[0029] In one embodiment of this application, the third bottom shell is provided with a second mounting hole and at least two third mounting holes, the second mounting hole is for mounting the corresponding heat exchange tube, and the at least two third mounting holes are for mounting the corresponding cooling tube.

[0030] In one embodiment of this application, the third cover is disposed on the side of the third bottom shell opposite to the housing, and together with the third bottom shell, forms a third flow cavity, and the corresponding heat exchange tube and at least two cooling tubes are in communication with the third flow cavity.

[0031] In one embodiment of this application, the third cover shell is welded and fixed to the third bottom shell.

[0032] In one embodiment of this application, the periphery of the second mounting hole is welded and fixed to the corresponding heat exchange tube, and the cooling tube is welded and fixed to the periphery of the corresponding third mounting hole;

[0033] In one embodiment of this application, the third bottom shell is welded and fixed to the first sidewall.

[0034] In one embodiment of this application, the height dimension h3 of the third water box in the second direction satisfies: h2 <h3<3h2。

[0035] In one embodiment of this application, the third water box extends along a third direction.

[0036] In one embodiment of this application, the water inlet and the water outlet are located on the same side of the housing.

[0037] In one embodiment of this application, the third direction is the vertical direction of the housing, and in the third direction, the water outlet is located on the upper edge of the second water box.

[0038] The upper edge of the second water box with the outlet is higher than the upper edge of the second water box opposite.

[0039] In one embodiment of this application, in a third-party direction, the upper surface of the water outlet is higher than the upper surface of the cooling channel assembly.

[0040] In one embodiment of this application, the cooling channel group includes a first cooling pipe, a second cooling pipe, and a third cooling pipe arranged sequentially along a third direction, wherein the cross-sectional area of ​​the first cooling pipe and / or the second cooling pipe is smaller than the cross-sectional area of ​​the third cooling pipe.

[0041] In one embodiment of this application, the cross-sectional shape of the first cooling pipe is circular;

[0042] In one embodiment of this application, the cross-sectional shape of the second cooling pipe is circular;

[0043] In one embodiment of this application, the cross-sectional shape of the third cooling pipe is elliptical.

[0044] In one embodiment of this application, the distance between the first cooling pipe and the second cooling pipe is greater than the distance between the second cooling pipe and the third cooling pipe.

[0045] To achieve the above objectives, this application also provides a gas water heater, including the heat exchanger described above.

[0046] In the heat exchanger of this application, a heat exchange chamber is formed inside the shell. Multiple heat exchange tubes are arranged in the heat exchange chamber, extending along a second direction and penetrating the third and fourth side walls respectively. Multiple first water boxes are arranged on the third and fourth side walls. Each pair of adjacent heat exchange tubes is connected through a first water box, so that multiple heat exchange tubes are connected in series to form a heat exchange channel. At the same time, cooling channel groups are arranged on the first and second side walls respectively, and second water boxes are arranged on the third and fourth side walls respectively. This allows water entering from the inlet to flow sequentially through the heat exchange channel, a cooling channel group, a second water box, another cooling channel group, and another second water box for heat exchange before flowing out from the outlet, thus achieving the function of preparing hot water while preventing the shell wall temperature from becoming too high. By setting the height dimension h1 of the first water box in the second direction to be greater than the height dimension h2 of the second water box in the second direction, the height dimension of the first water box in the second direction is increased. When the projected area of ​​the first water box on its side wall is the same, the volume of the first water box is increased, which reduces the flow velocity at the first water box, thereby reducing the local resistance at the first water box and improving the overall heat exchange efficiency of the heat exchanger. Attached Figure Description

[0047] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0048] Figure 1 is a structural schematic diagram of the heat exchanger of this application from one perspective;

[0049] Figure 2 is a schematic diagram of the structure after the first water box and the third water box are hidden in the embodiment of Figure 1;

[0050] Figure 3 is a structural schematic diagram of the heat exchanger of this application from another perspective;

[0051] Figure 4 is a schematic diagram of the structure of the first water box in an embodiment of this application;

[0052] Figure 5 is another perspective view of the embodiment in Figure 4;

[0053] Figure 6 is a schematic diagram of the structure of the third water box in the embodiment of this application;

[0054] Figure 7 is a schematic diagram of the structure of the mounting plate on the third sidewall in an embodiment of this application;

[0055] Figure 8 is a schematic diagram of the structure of the mounting plate on the fourth sidewall side in an embodiment of this application;

[0056] Figure 9 is a cross-sectional view of the heat exchanger of this application.

[0057] Explanation of icon numbers:

[0058]

[0059] The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Embodiments of the present invention

[0060] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of the embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0061] It should be noted that if the embodiments of this application involve directional indicators (such as up, down, left, right, front, back, etc.), the directional indicators are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indicators will also change accordingly.

[0062] Meanwhile, the meaning of "and / or" or "and / or" appearing throughout the text is that it includes three options. Taking "A and / or B" as an example, it includes option A, option B, or an option that satisfies both A and B.

[0063] Furthermore, if the embodiments of this application involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, features defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions of various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. If the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed in this application.

[0064] This application proposes a heat exchanger. The aim is to improve heat exchange efficiency by increasing the volume of the water box connecting adjacent heat exchange tubes at bends, thereby reducing local resistance at these bends. It is understood that this heat exchanger can be applied to both fully premixed combustion gas water heaters and atmospheric combustion gas water heaters. For ease of understanding, the following explanation uses an example of the heat exchanger being applied to a fully premixed combustion gas water heater.

[0065] In the embodiments of this application, as shown in Figures 1 to 5, the heat exchanger includes a shell 100, a plurality of heat exchange tubes 200, a plurality of first water boxes 310, two sets of cooling channel groups (401 / 402 / 403) and two second water boxes 320.

[0066] The housing 100 includes a first sidewall 110 and a second sidewall 120 opposite to each other along a first direction, and a third sidewall 130 and a fourth sidewall 140 opposite to each other along a second direction. The first sidewall 110, the fourth sidewall 140, the second sidewall 120, and the third sidewall 130 are connected end to end to form a heat exchange chamber B that is open at both ends in a third direction. The first direction, the second direction, and the third direction intersect each other. A plurality of heat exchange tubes 200 are disposed in the heat exchange chamber B, and the two ends of the heat exchange tubes 200 extend along the second direction to pass through the third sidewall 130 and the fourth sidewall 140 respectively. A plurality of first water boxes 310 are respectively disposed in the third sidewall 130 and the fourth sidewall 140. Each pair of adjacent heat exchange tubes 200 passes through a first water box. 310 is connected so that multiple heat exchange tubes 200 are connected in series to form a heat exchange channel 201, and the heat exchange channel 201 is provided with a water inlet 501; two sets of cooling channel groups (401 / 402 / 403) are respectively provided on the first side wall 110 and the second side wall 120, and are connected to the heat exchange channel 201; two second water boxes 320 are respectively provided on the third side wall 130 and the fourth side wall 140; one of the second water boxes 320 connects the two sets of cooling channel groups (401 / 402 / 403), and the other second water box 320 is provided with a water outlet 502; the height dimension h1 of the first water box 310 in the second direction and the height dimension h2 of the second water box 320 in the second direction satisfy: h1>h2.

[0067] It is understandable that the first direction, the second direction, and the third direction can be determined according to the actual situation and are not limited to a specific combination of directions. For ease of explanation, this specification uses the first direction as the front-back direction of the housing 100, the second direction as the left-right direction of the housing 100, and the third direction as the up-down direction of the housing 100.

[0068] The housing 100 includes a first sidewall 110, a fourth sidewall 140, a second sidewall 120, and a third sidewall 130 connected end-to-end. It is understood that the first sidewall 110 and the second sidewall 120 are the front and rear sidewalls, respectively, and the third sidewall 130 and the fourth sidewall 140 are the left and right sidewalls, respectively. In one embodiment, the cross-section of the housing 100 is formed into a generally "U"-shaped structure, with the combustion component 600 installed at the upper opening, and the heat exchange tube 200 located near the lower opening of the housing 100. The first sidewall 110, the fourth sidewall 140, the second sidewall 120, and the third sidewall 130 can be four independent side plate structures, fixed together by welding or riveting; alternatively, the four sidewalls can be a one-piece molded structure, such as formed by bending sheet metal. In this embodiment, considering the installation of internal components such as heat exchange components and cooling pipes, the four sidewalls are independently formed before assembly and fixation. A heat exchange chamber B is formed inside the shell 100. The mixture of gas and air can be ignited in the heat exchange chamber B, or high-temperature flue gas from the outside can flow into the heat exchange chamber B. The high-temperature flue gas can exchange heat with the heat exchange channel 201, the two sets of cooling channels (401 / 402 / 403) and each water box to achieve the function of preparing hot water.

[0069] Multiple heat exchange tubes 200 are disposed within heat exchange chamber B and extend along a second direction to pass through the third sidewall 130 and the fourth sidewall 140, respectively. Each pair of adjacent heat exchange tubes 200 is connected through a first water box 310, thereby forming a heat exchange channel 201 by connecting multiple heat exchange tubes 200 in series. In one embodiment, the multiple heat exchange tubes 200 are arranged at intervals along a first direction, and the high-temperature flue gas in heat exchange chamber B can exchange heat through the gaps between adjacent heat exchange tubes 200.

[0070] Cooling channel groups (401 / 402 / 403) are respectively provided on the first side wall 110 and the second side wall 120, and the cooling channel groups (401 / 402 / 403) are connected to the heat exchange channel 201. At the same time, two second water boxes 320 are respectively provided on the third side wall 130 and the fourth side wall 140. One of the second water boxes 320 connects the two cooling channel groups (401 / 402 / 403), and the other second water box 320 is provided with an outlet 502, so that the water entering from the inlet 501 will flow through the heat exchange channel 201, one cooling channel group (401 / 402 / 403), one second water box 320, another cooling channel group (401 / 402 / 403), and another second water box 320 in sequence, and then flow out from the outlet 502 after heat exchange. This configuration ensures that water flows over each side wall of the casing 100, which effectively reduces the temperature of each wall surface of the casing 100, while also improving heat utilization and accelerating heat exchange efficiency.

[0071] Understandably, in this embodiment, the first water box 310 is used to connect two adjacent heat exchange tubes 200 in series. The connection method between the first water box 310 and its side wall can be determined according to the actual situation. For example, the first water box 310 can be a box structure independent of the side wall. In this case, the height dimension h1 of the first water box 310 in the second direction can be understood as the height dimension of the first water box 310 itself in the second direction; or the first water box 310 can be a convex structure formed by the outward protrusion of the side wall. In this case, the height dimension h1 of the first water box 310 in the second direction can be understood as the height dimension of the first water box 310 protruding from its side wall in the second direction. The second water box 320 is used to connect the two sets of cooling channel groups (401 / 402 / 403) in series or to connect the cooling channel groups (401 / 402 / 403) to the outlet 502. The two sets of cooling channel groups (401 / 402 / 403) are located on the opposite first side wall 110 and second side wall 120 respectively. The second water box 320 can cover the third side wall 130 and the fourth side wall 140 in the front-back direction. The height dimension of the second water box 320 in the second direction is h2, which can be understood as the height dimension of the second water box 320 protruding from its side wall in the second direction.

[0072] By setting the height dimensions of both water tanks to satisfy h1>h2, compared to the related art where the first water tank 310 and the second water tank 320 use the same height dimension, this embodiment increases the height dimension of the first water tank 310 in the second direction. Therefore, given a fixed projected area of ​​the first water tank 310 on its sidewall, this embodiment can increase the volume of the first water tank 310, thereby reducing the flow velocity at the first water tank 310. According to the local resistance formula... It can be seen that when the flow rate decreases, the local resistance decreases. Therefore, this embodiment can effectively reduce the local resistance at the first water box 310 and improve the overall heat exchange efficiency of the heat exchanger.

[0073] In one embodiment, multiple first water boxes 310 are manufactured independently, and then each first water box 310 is installed onto the housing 100. This ensures that the height h1 of the first water box 310 is higher than the height of multiple water boxes manufactured as a single piece, effectively reducing local resistance at the connection between adjacent heat exchange tubes 200. In one embodiment, the height h1 of the first water box 310 is not less than 12mm.

[0074] In summary, in the heat exchanger of this application, a heat exchange chamber B is formed within the shell 100. Multiple heat exchange tubes 200 extending along a second direction and passing through the third sidewall 130 and the fourth sidewall 140 are arranged in the heat exchange chamber B. Multiple first water boxes 310 are arranged on the third sidewall 130 and the fourth sidewall 140. Each pair of adjacent heat exchange tubes 200 is connected through a first water box 310, so that the multiple heat exchange tubes 200 are connected in series to form a heat exchange flow channel 201. Simultaneously, cooling flows are respectively arranged on the first sidewall 110 and the second sidewall 120. The cooling channel group (401 / 402 / 403) has a second water box 320 set on the third side wall 130 and the fourth side wall 140 respectively. The water entering from the inlet 501 will flow through the heat exchange channel 201, a cooling channel group (401 / 402 / 403), a second water box 320, another cooling channel group (401 / 402 / 403), and another second water box 320 in sequence for heat exchange, and then flow out from the outlet 502. This achieves the function of preparing hot water while preventing the wall temperature of the shell 100 from getting too high. By setting the height dimension h1 of the first water box 310 in the second direction to be greater than the height dimension h2 of the second water box 320 in the second direction, the height dimension of the first water box 310 in the second direction is increased. When the projected area of ​​the first water box 310 on its side wall is the same, the volume of the first water box 310 is increased, which reduces the flow velocity at the first water box 310, thereby reducing the local resistance at the first water box 310 and improving the overall heat exchange efficiency of the heat exchanger.

[0075] In one embodiment of this application, as shown in Figures 1 to 5, the height dimension h1 of the first water box 310 in the second direction and the height dimension h2 of the second water box 320 in the second direction satisfy: h1 < 3h2.

[0076] Understandably, the height h1 of the first water box 310 in the second direction should not be too high. If it is too high, the width of the heat exchanger in the second direction will be too wide, resulting in excessive space occupation when installed in the water heater. Based on this, in this embodiment, the height h1 of the first water box 310 in the second direction is set to satisfy h1 < 3h2. This setting can reduce local resistance loss while avoiding an excessively large overall structure of the heat exchanger.

[0077] In one embodiment of this application, as shown in Figures 1 to 5, multiple first water boxes 310 on the same sidewall are independently arranged.

[0078] In this embodiment, each first water box 310 can be manufactured and formed separately before being assembled onto the third side wall 130 and the fourth side wall 140. This design ensures that the height of the first water box 310 in the second direction is higher than that of a conventional water box formed by stamping multiple water boxes in one piece, effectively reducing local resistance loss.

[0079] In one embodiment, the first water box 310 may be manufactured by stamping a single sheet, or by casting, or by machining.

[0080] Specifically, as shown in Figure 4, the first water box 310 includes a first bottom shell 311 and a first cover shell 312. The first bottom shell 311 is provided with two first mounting holes 3111, and two adjacent heat exchange tubes 200 are respectively inserted into the two first mounting holes 3111. The first cover shell 312 covers the side of the first bottom shell 311 away from the shell 100 and forms a first flow cavity with the first bottom shell 311. Two adjacent heat exchange tubes 200 are connected to the first flow cavity.

[0081] This embodiment describes the structure of the first water box 310. A first bottom shell 311 and a first cover shell 312 enclose a first flow cavity. The first bottom shell 311 has two first mounting holes 3111, and two heat exchange tubes 200 are respectively inserted into the two first mounting holes 3111, allowing the first flow cavity to connect two adjacent heat exchange tubes 200 in series. In one embodiment, the first cover shell 312 is welded to the first bottom shell 311, ensuring the structural reliability of the first water box 310 while improving the sealing of the first flow cavity to prevent leakage.

[0082] It should be noted that in this embodiment, the first water box 310 is a structure independent of the housing 100, and two heat exchange tubes 200 extend from the third side wall 130 or the fourth side wall 140 to connect with the first water box 310. In one embodiment, the heat exchange tubes 200 are welded and fixed to the periphery of the corresponding first mounting holes 3111 to ensure the installation seal between the heat exchange tubes 200 and the first bottom shell 311. In another embodiment, the first bottom shell 311 is welded and fixed to the corresponding third side wall 130 or the fourth side wall 140 to improve the connection reliability between the first water box 310 and the housing 100.

[0083] In one embodiment of this application, as shown in Figures 1 to 3, 7, and 8, the second water box 320 extends along the first direction and is disposed on the corresponding third sidewall 130 and fourth sidewall 140. This design can increase the area of ​​the second water box 320 covering the corresponding sidewall, increase the heat exchange area with the wall of the shell 100, and further accelerate the efficiency of cooling the wall of the shell 100.

[0084] Understandably, since the second water box 320 covers a large area of ​​the third sidewall 130 and the fourth sidewall 140, and due to the high water pressure, the second water box 320 may deform or even be damaged. Therefore, in one embodiment, the outer sidewall of the second water box 320 is provided with a reinforcing recess 322 recessed towards its corresponding sidewall to increase the structural strength of the second water box 320. In one embodiment, the reinforcing recess 322 of the second water box 320 can be recessed to fit snugly against its corresponding sidewall and fixed by welding.

[0085] In one embodiment of this application, as shown in Figures 1 to 3, 7 and 8, the heat exchanger further includes two mounting plates 321 disposed outside the third sidewall 130 and the fourth sidewall 140. The mounting plates 321 protrude outward in the direction away from the housing 100 to form a second water box 320. The first water box 310 is disposed outside the mounting plates 321. The mounting plates 321 are provided with a plurality of first through holes 3211 through which the heat exchange tubes 200 pass.

[0086] In this embodiment, by providing an mounting plate 321 on the outer side of the third sidewall 130 and the fourth sidewall 140, a second water box 320 can be formed by protruding outward from the mounting plate 321, ensuring the integrity of the third sidewall 130 and the fourth sidewall 140, improving the sealing of the heat exchange chamber B, and preventing the leakage of high-temperature flue gas. The first water box 310 is located on the outer side of the mounting plate 321. In one embodiment, the first bottom shell 311 of the first water box 310 is welded and fixed to the mounting plate 321, and the heat exchange tube 200 passes through the first through hole 3211 on the mounting plate 321 into the first water box 310. In one embodiment, the heat exchange tube 200 is welded and sealed to the periphery of the first through hole 3211.

[0087] In one embodiment of this application, as shown in Figures 1 to 3 and Figure 9, each cooling channel group (401 / 402 / 403) includes at least two cooling pipes arranged in parallel along a third direction.

[0088] In this embodiment, each cooling channel group (401 / 402 / 403) includes at least two cooling pipes arranged in parallel along a third direction. That is, the at least two cooling pipes are arranged in parallel with the side wall of the heat exchange chamber B along the flue gas flow direction. Compared with using only a single cooling pipe, this design increases the heat exchange area of ​​the cooling pipes and accelerates the cooling speed of the side wall surface of the shell 100. With at least two cooling pipes arranged in parallel, the inlets and outlets of the at least two cooling pipes are connected to each other. The water entering the at least two cooling pipes from the inlets is at a lower temperature. Compared with the series connection, this increases the temperature difference between the water in the cooling pipes and the heat exchange chamber B, resulting in higher heat exchange efficiency. Furthermore, while obtaining the same heat exchange area on the wall as in the series connection, it can increase the flow cross-sectional area, reduce water flow resistance, and increase the flow rate.

[0089] Furthermore, as shown in Figures 1 to 3 and Figure 6, the heat exchanger also includes a third water box 330 disposed on the third side wall 130 or the fourth side wall 140, the third water box 330 connecting the cooling channel assembly (401 / 402 / 403) on the first side wall 110 to one end of the heat exchange channel 201.

[0090] The third water box 330 serves to connect the heat exchange channel 201 with at least two cooling pipes on the first side wall 110. In other words, the third water box 330 acts as a transition water box between series and parallel pipes, allowing water flowing out of the heat exchange channel 201 to be evenly distributed in the third water box 330 before simultaneously entering the at least two parallel cooling pipes. This reduces water flow resistance and achieves better flow distribution. Specifically, cold water enters from the inlet 501, flows sequentially through the heat exchange channel 201, the third water box 330, the cooling channel group (401 / 402 / 403) on the first side wall 110, the second water box 320 on the fourth side wall 140, the cooling channel group (401 / 402 / 403) on the second side wall 120, and the second water box 320 on the third side wall 130, and then flows out from the outlet 502.

[0091] Furthermore, as shown in Figures 1, 2, and 4 to 6, the third water box 330 and the first water box 310 are independently arranged. In this embodiment, the third water box 330 and the first water box 310 are manufactured and formed separately before being assembled onto the third side wall 130 or the fourth side wall 140. This design ensures that the height of the first water box 310 and the third water box 330 in the second direction is higher than the height of a conventional water box formed by integral stamping of multiple water boxes, which can effectively reduce local resistance and improve heat exchange efficiency.

[0092] In one embodiment, the third water box 330 may be manufactured by stamping a single sheet, or by casting, or by machining.

[0093] Specifically, as shown in Figure 6, the third water box 330 includes a third bottom shell 331 and a third cover shell 332. The third bottom shell 331 has a second mounting hole 3311 and at least two third mounting holes 3312. The second mounting hole 3311 is for mounting the corresponding heat exchange tube 200, and the at least two third mounting holes 3312 are for mounting the corresponding cooling tubes. The third cover shell 332 covers the side of the third bottom shell 331 away from the shell 100 and forms a third flow cavity with the third bottom shell 331. The corresponding heat exchange tube 200 and at least two cooling tubes are all connected to the third flow cavity.

[0094] This embodiment describes the structure of the third water box 330. The third bottom shell 331 and the third cover shell 332 enclose a third flow cavity. The third bottom shell 331 has a second mounting hole 3311 and at least two third mounting holes 3312. The heat exchange tube 200 at the end passes through the second mounting hole 3311, and at least two cooling tubes are respectively inserted into the at least two third mounting holes 3312, so that the third flow cavity can connect the heat exchange channel 201 with the at least two cooling tubes. It can be understood that the water flowing from the heat exchange tube 200 can be mixed in the third flow cavity before entering the at least two cooling tubes. By independently molding the third water box 330, the height dimension of the third water box 330 in the second direction can be increased, the volume of the third water box 330 can be increased, and local resistance can be further reduced.

[0095] In one embodiment, the third cover 332 is welded and fixed to the third bottom cover 331, which ensures the structural reliability of the third water box 330 while improving the sealing performance of the third flow cavity to prevent water leakage.

[0096] It should be noted that in this embodiment, the third water box 330 is a structure independent of the housing 100. The heat exchange tube 200 and at least two cooling tubes extend from the third side wall 130 or the fourth side wall 140 to connect with the third water box 330. In one embodiment, the heat exchange tube 200 is welded and fixed to the periphery of the corresponding second mounting hole 3311 to ensure the installation seal between the heat exchange tube 200 and the third bottom shell 331. The cooling tube is welded and fixed to the periphery of the corresponding third mounting hole 3312 to ensure the installation seal between the cooling tube and the third bottom shell 331. In one embodiment, the third bottom shell 331 is welded and fixed to the first side wall 110 to improve the connection reliability between the third water box 330 and the housing 100.

[0097] Furthermore, as shown in Figures 2 and 6, the height dimension h3 of the third water box 330 in the second direction satisfies: h2 <h3<3h2。

[0098] By setting the height h3 of the third water box 330 in the second direction to be greater than the height h2 of the second water box 320 in the second direction, compared with the related technology in which the third water box 330 and the second water box 320 adopt the same height dimension, this embodiment increases the height dimension of the third water box 330 in the second direction. Therefore, when the projected area of ​​the third water box 330 on its side wall is constant, this embodiment can increase the volume of the third water box 330, thereby reducing the flow velocity at the third water box 330, reducing the local resistance at the third water box 330, and improving the overall heat exchange efficiency of the heat exchanger.

[0099] Meanwhile, the height h3 of the third water box 330 in the second direction should not be too high. If it is too high, the width of the heat exchanger in the second direction will be too wide, resulting in excessive space occupation when installed in the water heater. Based on this, in this embodiment, the height h3 of the third water box 330 in the second direction is set to satisfy h3 < 3h2. This setting can reduce local resistance loss while avoiding an excessively large overall structure of the heat exchanger.

[0100] As an example, the height dimension h3 of the third water box 330 in the second direction can be equal to the height dimension h1 of the first water box 310 in the second direction. This design facilitates molding and manufacturing, and simplifies the complexity of the process.

[0101] Furthermore, as shown in Figure 1, the third water box 330 extends along the third direction. This design, on the one hand, allows the third water box 330 to cover all the cooling pipes arranged in parallel along the third direction, ensuring the amount of water entering at least two cooling pipes; on the other hand, it increases the coverage area of ​​the third water box 330 on the third side wall 130, increasing the heat exchange area with the wall of the shell 100, and further accelerating the efficiency of cooling the wall of the shell 100.

[0102] In one embodiment of this application, as shown in Figures 1 and 2, the inlet 501 and the outlet 502 are located on the same side of the housing 100. This design facilitates the external piping. In another embodiment, both the inlet 501 and the outlet 502 are located on the same side of the third sidewall 130.

[0103] Furthermore, in the third direction, the water outlet 502 is located on the upper edge of the second water box 320 to which it is located; the upper edge of the second water box 320 with the water outlet 502 is higher than the upper edge of the opposite second water box 320.

[0104] This design allows water to enter from a low position and exit from a high position, making the outlet 502 relatively high. This ensures that the pipes through which the water flows are filled with water, thus preventing the upper cooling pipes from being incompletely filled and causing severe vaporization noise under low flow conditions.

[0105] Furthermore, in a third-order direction, the upper surface of the outlet 502 is higher than the upper surface of the cooling channel assembly (401 / 402 / 403). This design prevents the upper cooling pipe from being incompletely filled under low flow conditions, thus avoiding severe vaporization noise. In one embodiment, the center horizontal line of the outlet 502 is flush with the center horizontal line of the uppermost first cooling pipe 401 in the cooling channel assembly, and the diameter of the outlet 502 is larger than the inner diameter of the first cooling pipe 401.

[0106] In one embodiment of this application, as shown in Figures 1 to 9, the cooling channel group (401 / 402 / 403) includes a first cooling pipe 401, a second cooling pipe 402 and a third cooling pipe 403 arranged sequentially along a third direction. The cross-sectional area of ​​the first cooling pipe 401 and / or the second cooling pipe 402 is smaller than the cross-sectional area of ​​the third cooling pipe 403.

[0107] Understandably, along the flue gas flow path, the downstream temperature is lower than the upstream temperature. Therefore, the flue gas temperature at the locations of the first cooling pipe 401 and the second cooling pipe 402 will be higher than the flue gas temperature at the location of the third cooling pipe 403. Because of the higher temperature at the locations of the first and second cooling pipes 401 and 402, there is a risk of high-temperature vaporization inside the pipes due to localized high temperatures on the pipe walls. Therefore, in this embodiment, the flow cross-sectional area of ​​the first cooling pipe 401 and / or the second cooling pipe 402 is set to be smaller than that of the third cooling pipe 403. This results in a relatively smaller heat exchange area between the first and second cooling pipes 401 and the high-temperature flue gas, reducing the risk of high-temperature vaporization. Simultaneously, since the third cooling pipe 403 is located in a relatively low-temperature flue gas region, its flow cross-sectional area is set to be relatively larger, increasing the heat exchange area between the third cooling pipe 403 and the flue gas to maximize heat utilization. This achieves the function of utilizing the high-temperature flue gas temperature in stages, improving the overall heat exchange efficiency of the heat exchanger.

[0108] The flow cross-sectional area of ​​the first cooling pipe 401 and / or the second cooling pipe 402 is smaller than the flow cross-sectional area of ​​the third cooling pipe 403. This can be understood as follows: only the flow cross-sectional area of ​​the first cooling pipe 401 is smaller than the flow cross-sectional area of ​​the third cooling pipe 403; or only the flow cross-sectional area of ​​the second cooling pipe 402 is smaller than the flow cross-sectional area of ​​the third cooling pipe 403; or both the flow cross-sectional areas of the first cooling pipe 401 and the second cooling pipe 402 are smaller than the flow cross-sectional area of ​​the third cooling pipe 403. It should be noted that the flow cross-sectional areas of the first cooling pipe 401 and the second cooling pipe 402 can be the same or different. In some embodiments, it is possible to choose that both have the same flow cross-sectional area, so that the water flow distribution of the cooling pipes on the sidewall of the housing 100 is more uniform, preventing the smaller cooling pipe from easily vaporizing at high temperatures due to uneven flow.

[0109] Furthermore, in practical applications, the number of cooling pipes is not limited to three as in the above embodiment; it can also be two, four, or more. In this embodiment, considering that setting two pipes may result in insufficient combustion distance, which could easily cause the flame to bake the fins in the heat exchange component; and setting four or more pipes may result in excessive combustion distance, which could affect heat exchange efficiency, this embodiment preferably sets three cooling pipes side by side.

[0110] Specifically, during manufacturing, the three cooling pipes and the shell 100 can be manufactured separately first, and then the three pipes can be assembled into the inner side wall of the heat exchange chamber B and fixed by welding.

[0111] In one embodiment, the flow cross-sectional shape of the first cooling pipe 401 is circular;

[0112] In one embodiment, the flow cross-sectional shape of the second cooling pipe 402 is circular;

[0113] In one embodiment, the cross-sectional shape of the third cooling pipe 403 is elliptical.

[0114] Furthermore, the distance between the first cooling pipe 401 and the second cooling pipe 402 is greater than the distance between the second cooling pipe 402 and the third cooling pipe 403.

[0115] This design ensures sufficient spacing between the first cooling pipe 401 and the second cooling pipe 402 for the installation of the ignition device 700, guaranteeing the installation distance between the ignition device 700 and the combustion component 600 in terms of height. It also cools the wall surface where the ignition device 700 is located, preventing the ignition device 700 from deforming or loosening due to heat, thus ensuring the installation reliability of the ignition device 700 and extending its service life.

[0116] As shown in Figures 1 to 9, in one embodiment, the cross-sectional shape of the heat exchange tube 200 is elliptical, and the major axis of the heat exchange tube 200 is aligned with the flue gas flow direction. By setting the heat exchange tube 200 as an elliptical tube, the heat exchange area of ​​the heat exchange tube 200 is increased. Simultaneously, aligning the major axis of the heat exchange tube 200 with the flue gas flow direction reduces the flow resistance of the high-temperature flue gas and improves heat exchange efficiency.

[0117] It should be noted that the flue gas temperature is distributed from high to low from top to bottom. By placing the first cooling pipe 401 and the second cooling pipe 402, which have smaller flow cross-sectional areas, at the higher flue gas temperature positions, the heat exchange area with the high-temperature flue gas can be reduced, preventing high-temperature vaporization. Placing the third cooling pipe 403, which has a larger flow cross-sectional area, at the lower flue gas temperature positions increases the heat exchange area, maximizing the utilization of heat at this location. Placing the finned heat exchanger tube 200 at the lower flue gas temperature positions results in an even larger heat exchange area, where the convective heat transfer capacity of the high-temperature flue gas is strongest, thus improving heat exchange efficiency. In this way, the high-temperature flue gas temperature is utilized in a stepped manner, allowing the heat from the high-temperature flue gas to be absorbed across the entire temperature range within the heat exchanger, thereby improving the heat exchanger's efficiency.

[0118] This application also proposes a gas water heater, which includes a heat exchanger. The specific structure of the heat exchanger is as described in the above embodiments. Since this gas water heater adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be described in detail here.

[0119] The above description is merely an embodiment of this application and does not limit the patent scope of this application. Any equivalent structural transformations made based on the inventive concept of this application and the contents of the specification and drawings of this application, or direct / indirect applications in other related technical fields, are included within the patent protection scope of this application.

Claims

1. A heat exchanger, wherein, The heat exchanger includes: The shell includes a first sidewall and a second sidewall opposite to each other along a first direction, and a third sidewall and a fourth sidewall opposite to each other along a second direction. The first sidewall, the fourth sidewall, the second sidewall, and the third sidewall are connected end to end to enclose a heat exchange chamber that is open at both ends in a third direction. The first direction, the second direction, and the third direction intersect each other. Multiple heat exchange tubes are disposed in the heat exchange chamber, and the two ends of the heat exchange tubes extend along the second direction to pass through the third side wall and the fourth side wall respectively; Multiple first water boxes are respectively disposed on the third side wall and the fourth side wall; each pair of adjacent heat exchange tubes are connected through a first water box, so that multiple heat exchange tubes are connected in series to form a heat exchange channel, and the heat exchange channel is provided with a water inlet; Two sets of cooling channels are respectively disposed on the first sidewall and the second sidewall, and are connected to the heat exchange channels; and Two second water boxes are respectively disposed on the third side wall and the fourth side wall; one of the second water boxes connects the two sets of cooling channel groups, and the other second water box is provided with a water outlet; Wherein, the height dimension h1 of the first water box in the second direction and the height dimension h2 of the second water box in the second direction satisfy: h1>h2.

2. The heat exchanger as claimed in claim 1, wherein, The height dimension h1 of the first water box in the second direction and the height dimension h2 of the second water box in the second direction satisfy: h1 < 3h2.

3. The heat exchanger as described in claim 1 or 2, wherein, Multiple first water boxes on the same side wall are set up independently.

4. The heat exchanger as described in claim 3, wherein, The first water box includes: The first bottom shell has two first mounting holes, and two adjacent heat exchange tubes are respectively inserted into the two first mounting holes; and The first cover is placed on the side of the first bottom shell away from the shell and forms a first flow cavity with the first bottom shell. The two adjacent heat exchange tubes are connected to the first flow cavity.

5. The heat exchanger as claimed in claim 4, wherein, The first cover shell is welded and fixed to the first bottom shell.

6. The heat exchanger as claimed in claim 4 or 5, wherein, The heat exchange tube is welded and fixed to the periphery of the corresponding first mounting hole; And / or, the first bottom shell is welded and fixed to the corresponding third sidewall or the fourth sidewall.

7. The heat exchanger according to any one of claims 1 to 6, wherein, The second water box extends along the first direction and is disposed on the corresponding third and fourth side walls.

8. The heat exchanger according to any one of claims 1 to 7, wherein, The heat exchanger also includes two mounting plates disposed outside the third and fourth side walls, the mounting plates protruding outward in a direction away from the shell to form the second water box; The first water box is located on the outside of the mounting plate, and the mounting plate has multiple first through holes for the heat exchange tubes to pass through.

9. The heat exchanger according to any one of claims 1 to 8, wherein, Each cooling channel group includes at least two cooling pipes arranged in parallel along a third direction; The heat exchanger also includes a third water box disposed on the third side wall or the fourth side wall, the third water box connecting the cooling channel assembly on the first side wall to one end of the heat exchange channel.

10. The heat exchanger as claimed in claim 9, wherein, The third water box is set up independently of the first water box.

11. The heat exchanger as claimed in claim 10, wherein, The third water tank includes: The third bottom shell has a second mounting hole and at least two third mounting holes, the second mounting hole for mounting the corresponding heat exchange tube, and the at least two third mounting holes for mounting the corresponding cooling tube; and The third cover is installed on the side of the third bottom shell away from the shell and forms a third flow cavity with the third bottom shell. The corresponding heat exchange tube and at least two cooling tubes are all in communication with the third flow cavity.

12. The heat exchanger as claimed in claim 11, wherein, The third cover shell is welded and fixed to the third bottom shell.

13. The heat exchanger as claimed in claim 11 or 12, wherein, The periphery of the second mounting hole is welded and fixed to the corresponding heat exchange tube, and the cooling tube is welded and fixed to the periphery of the corresponding third mounting hole; And / or, the third bottom shell is welded and fixed to the first sidewall.

14. The heat exchanger according to any one of claims 9 to 13, wherein, The height dimension h3 of the third water box in the second direction satisfies: h2 <h3<3h2。 15. The heat exchanger according to any one of claims 9 to 14, wherein, The third water box extends in a third direction.

16. The heat exchanger according to any one of claims 1 to 15, wherein, The inlet and the outlet are located on the same side of the housing.

17. The heat exchanger according to any one of claims 1 to 16, wherein, The third direction is the vertical direction of the housing. In the third direction, the water outlet is located on the upper edge of the second water box. The upper edge of the second water box with the outlet is higher than the upper edge of the second water box opposite.

18. The heat exchanger according to any one of claims 1 to 17, wherein, In the third direction, the upper surface of the water outlet is higher than the upper surface of the cooling channel assembly.

19. The heat exchanger according to any one of claims 1 to 18, wherein, The cooling channel assembly includes a first cooling pipe, a second cooling pipe, and a third cooling pipe arranged sequentially along a third direction, wherein the cross-sectional area of ​​the first cooling pipe and / or the second cooling pipe is smaller than the cross-sectional area of ​​the third cooling pipe.

20. The heat exchanger as claimed in claim 19, wherein, The cross-sectional shape of the first cooling pipe is circular; And / or, the flow cross-sectional shape of the second cooling pipe is circular; And / or, the cross-sectional shape of the third cooling pipe is elliptical.

21. The heat exchanger as claimed in claim 19 or 20, wherein, The distance between the first cooling pipe and the second cooling pipe is greater than the distance between the second cooling pipe and the third cooling pipe.

22. A gas-fired water heater, wherein, The gas water heater includes a heat exchanger as described in any one of claims 1 to 21.

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