Heat exchanger and gas water heater

Abstract

Disclosed in the present application are a heat exchanger and a gas water heater. The heat exchanger comprises a housing, a plurality of heat exchange tubes, and a plurality of first water boxes, wherein a heat exchange chamber is formed in the housing; the plurality of heat exchange tubes are arranged side by side in a first direction in the heat exchange chamber, and two ends of each heat exchange tube respectively extend through two opposite side walls of the housing in a second direction; the plurality of first water boxes are respectively provided on the two opposite side walls of the housing in the second direction, and two adjacent heat exchange tubes are in communication by means of one first water box, such that the plurality of heat exchange tubes are connected in series to form a heat exchange flow channel; and the length of a connecting line between the outermost ends of two adjacent heat exchange tubes in the first direction is defined as L, the diameter of each heat exchange tube in a third direction is defined as D1, and the projected area of each first water box on the side wall on which the first water box is mounted is defined as S, satisfying: S>L×D1, wherein the first direction, the second direction and the third direction intersect each other pairwise.

Description

Heat exchangers and gas water heaters

[0001] Related applications

[0002] This application claims priority to Chinese patent application No. 202411908271.7, 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, and a plurality of first water boxes.

[0008] In one embodiment of this application, a heat exchange chamber is formed inside the housing.

[0009] In one embodiment of this application, the plurality of heat exchange tubes are arranged side by side in the heat exchange chamber along a first direction, and the two ends of the heat exchange tubes extend to pass through the opposite side walls of the shell along a second direction.

[0010] In one embodiment of this application, the plurality of first water boxes are respectively disposed on opposite side walls of the shell along the second direction, and 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.

[0011] In one embodiment of this application, the length of the line connecting the outermost ends of two adjacent heat exchange tubes in the first direction is defined as L, the diameter of the heat exchange tube in the third direction is defined as D1, and the projected area of ​​the first water box on its installed side wall is defined as S, satisfying: S>L×D1; wherein, the first direction, the second direction, and the third direction intersect each other.

[0012] In one embodiment of this application, the following condition is satisfied: S≥L×L.

[0013] In one embodiment of this application, the first water box has a square shape projected onto the side wall where it is installed.

[0014] In one embodiment of this application, the heat exchanger further includes a cooling channel assembly disposed on the side wall of the shell, the cooling channel assembly including at least two cooling pipes arranged in parallel along a third direction;

[0015] The heat exchanger also includes a third water box disposed on one side wall of the shell in the second direction, the third water box connecting the cooling channel assembly to one end of the heat exchange channel.

[0016] In one embodiment of this application, the third water box extends along a third direction.

[0017] In one embodiment of this application, a recess is provided on one side of the third water box; in the third direction, the heat exchange tube connected to the third water box is located below the recess.

[0018] 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.

[0019] In the third direction, the recess is located on the side of the second cooling pipe opposite to the first cooling pipe.

[0020] In one embodiment of this application, the projected shape of the recessed portion on the side wall where the third water box is installed is a concave arc shape.

[0021] In one embodiment of this application, the center of the recess is at the same height as the center of the third cooling pipe.

[0022] In one embodiment of this application, the cross-sectional shape of the first cooling pipe is circular.

[0023] In one embodiment of this application, the cross-sectional shape of the second cooling pipe is circular.

[0024] In one embodiment of this application, the cross-sectional shape of the third cooling pipe is elliptical.

[0025] In one embodiment of this application, the third water box and the first water box are an integral structure.

[0026] In one embodiment of this application, the heat exchanger further includes two mounting plates disposed outside the two side walls of the housing in the second direction, and the first water box and the third water box are both formed by the mounting plates protruding outward in the direction away from the housing.

[0027] In one embodiment of this application, the heat exchanger further includes two second water boxes disposed on the two side walls of the shell along the second direction, the second water boxes being formed by the mounting plate protruding outward in a direction away from the shell;

[0028] The cooling channel assembly is provided on both sides of the housing along the first direction;

[0029] The heat exchange channel, the third water box, one of the cooling channel groups, one of the second water boxes, another cooling channel group, and another second water box are connected in sequence. The heat exchange channel is provided with an inlet, and the second water box located downstream of the fluid is provided with an outlet.

[0030] In one embodiment of this application, the lower surface of the outlet is higher than the upper surface of the inlet.

[0031] 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.

[0032] The upper edge of the second water box with the outlet is higher than the upper edge of the opposite second water box; and / or, the upper edge of the second water box with the outlet is higher than the upper edge of the third water box.

[0033] 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.

[0034] In one embodiment of this application, the second water box has a protrusion on its side along the first direction that protrudes toward the first water box;

[0035] In the third direction, the convex hull corresponds to the cooling pipe at the bottom of the cooling channel group.

[0036] In one embodiment of this application, the first water boxes located on both sides of the same sidewall are provided with avoidance recesses corresponding to the convex bulge.

[0037] In one embodiment of this application, the heat exchange tube is an elliptical tube; the major axis of the heat exchange tube is aligned with a third direction, and the minor axis of the heat exchange tube is aligned with a first direction.

[0038] To achieve the above objectives, this application also provides a gas water heater, including the heat exchanger described above.

[0039] In the heat exchanger of this application, a heat exchange chamber is formed inside the shell. Multiple heat exchange tubes are arranged side-by-side along a first direction within the heat exchange chamber. Each heat exchange tube extends to both ends and passes through opposite side walls of the shell along a second direction. Multiple first water boxes are arranged on the opposite side walls along the second direction. Each pair of adjacent heat exchange tubes is connected through a first water box, allowing the multiple heat exchange tubes to be connected in series to form a heat exchange channel. This channel can exchange heat with the high-temperature flue gas inside the heat exchange chamber, thus achieving the function of producing hot water. By setting the projected area of ​​the first water box on its mounting side wall to be greater than the product of the length of the line connecting the outermost ends of two adjacent heat exchange tubes connected to the same first water box in the first direction and the diameter of the heat exchange tube in the third direction, the projected area of ​​the first water box on its mounting side wall is increased. Given a fixed height of the first water box in the second direction, this increases the volume of the first water box, reducing the flow velocity at the first water box and thus reducing local resistance at the first water box, thereby improving the overall heat exchange efficiency of the heat exchanger. Attached Figure Description

[0040] 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.

[0041] Figure 1 is a structural schematic diagram of the heat exchanger of this application from one perspective;

[0042] Figure 2 is a structural schematic diagram of the heat exchanger of this application from another perspective;

[0043] Figure 3 is a schematic diagram showing the distribution of the first water box, the second water box and the third water box on the third sidewall in an embodiment of this application;

[0044] Figure 4 is a schematic diagram of the distribution of the first water box and the second water box on the fourth side wall in an embodiment of this application;

[0045] Figure 5 is an exploded view of the shell and mounting plate in the heat exchanger of this application;

[0046] Figure 6 is a schematic diagram of the structure after the first water box, the second water box and the third water box are hidden in the embodiment of this application;

[0047] Figure 7 is a schematic diagram of the structure of the mounting plate on the third sidewall in an embodiment of this application;

[0048] Figure 8 is a schematic diagram of the structure of the mounting plate on the fourth sidewall side in an embodiment of this application;

[0049] Figure 9 is a cross-sectional view of the heat exchanger of this application;

[0050] Figure 10 is a structural schematic diagram of the heat exchanger of this application when it is equipped with combustion components and an ignition device.

[0051] Explanation of icon numbers:

[0052]

[0053] 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

[0054] 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.

[0055] 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.

[0056] 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.

[0057] 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.

[0058] 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.

[0059] In the embodiments of this application, as shown in Figures 1 to 4 and Figure 9, the heat exchanger includes a shell 100, a plurality of heat exchange tubes 200 and a plurality of first water boxes 310.

[0060] A heat exchange chamber B is formed inside the shell 100; a plurality of heat exchange tubes 200 are arranged side by side in the heat exchange chamber B along a first direction, and the two ends of the heat exchange chamber B extend to pass through the opposite side walls of the shell 100 along a second direction; a plurality of first water boxes 310 are respectively arranged on the opposite side walls of the shell 100 along the second direction, and each pair of adjacent heat exchange tubes 200 are connected through a first water box 310, so that the plurality of heat exchange tubes 200 are connected in series to form a heat exchange channel 201;

[0061] Let L be the length of the line connecting the outermost ends of two adjacent heat exchange tubes 200 connected to the same first water box 310 in the first direction, D1 be the diameter of the heat exchange tube 200 in the third direction, and S be the projected area of ​​the first water box 310 on its installed side wall, satisfying S>L×D1; wherein the first direction, the second direction and the third direction intersect each other.

[0062] 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.

[0063] In this embodiment, the shell 100 has a first sidewall 110 and a second sidewall 120 opposite each other in a first direction, and a third sidewall 130 and a fourth sidewall 140 opposite each other in 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 with an opening in a third direction. In one embodiment, the cross-section of the shell 100 is formed into a generally "U"-shaped structure, and a combustion component 600 can be installed at the upper opening. The heat exchange tube 200 can be located near the lower opening of the shell 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; or, the four sidewalls can be an integrally formed 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 assembled and fixed after being formed independently. 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 to achieve the function of preparing hot water.

[0064] Multiple heat exchange tubes 200 are arranged side-by-side in heat exchange chamber B along a first direction. The two ends of each heat exchange tube 200 extend along a second direction, passing through a third side wall 130 and a fourth side wall 140, respectively. Each pair of adjacent heat exchange tubes 200 is connected via a first water box 310, allowing multiple heat exchange tubes 200 to be connected in series to form a heat exchange channel 201. High-temperature flue gas in heat exchange chamber B can pass through the gaps between adjacent heat exchange tubes 200 for heat exchange, thus increasing the heat exchange area. The length L of the line connecting the outermost ends of two adjacent heat exchange tubes 200 connected to the same first water box 310 in the first direction can be understood as the length of the line connecting the outer periphery of the two adjacent heat exchange tubes 200 to the outermost point of the line extending along the diameter in the front-back direction.

[0065] By setting the length L of the line connecting the outermost ends of two adjacent heat exchange tubes 200 connected to the same first water box 310 in the first direction, the diameter D1 of the heat exchange tube 200 in the third direction, and the projected area S of the first water box 310 on its mounting sidewall to satisfy S>L×D1, compared with the related technology where the projected area of ​​the first water box 310 on its sidewall is less than or equal to L×D1, this embodiment increases the projected area of ​​the first water box 310 on its sidewall. Therefore, when the height of the first water box 310 protruding from its sidewall is constant, this embodiment can increase the volume of the first water box 310, thereby reducing the flow velocity at the first water box 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.

[0066] Understandably, the connection method between the first water box 310 and its side wall can be determined according to the actual situation. For example, it can be a box structure independent of the side wall, or a convex bulge 322 structure formed by the outward protrusion of the side wall. The shape and structure of the first water box 310 can be determined according to the actual situation. For example, it can be a rectangular structure, a triangular structure, a cylindrical structure, or some other irregular structure. The projection shape of the first water box 310 on its installed side wall can also be determined according to the actual situation. For example, it can be a rectangular structure, a triangular structure, a cylindrical structure, or some other shape. In this embodiment, the projection shape of the first water box 310 on its installed side wall is square, which facilitates molding and manufacturing, and reduces the occurrence of narrow spaces and reduces flow resistance.

[0067] In summary, in the heat exchanger of this application, a heat exchange chamber B is formed inside the shell 100. Multiple heat exchange tubes 200 are arranged side by side along a first direction in the heat exchange chamber B. The two ends of each heat exchange tube 200 extend to pass through the opposite side walls of the shell 100 along a second direction. Multiple first water boxes 310 are arranged on the opposite side walls along the second direction. Every two adjacent heat exchange tubes 200 are connected through a first water box 310, so that multiple heat exchange tubes 200 are connected in series to form a heat exchange channel 201, which can exchange heat with the high-temperature flue gas in the heat exchange chamber B and realize the function of preparing hot water. By setting the projected area S of the first water box 310 on its installed side wall to be greater than the product of the length L of the line connecting the outermost ends of two adjacent heat exchange tubes 200 connected to the same first water box 310 in the first direction and the diameter D1 of the heat exchange tube 200 in the third direction, the projected area of ​​the first water box 310 on its installed side wall is increased. When the height dimension of the first water box 310 in the second direction is constant, 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.

[0068] To further reduce the local resistance of the first water box 310, as shown in Figures 1 to 4 and Figure 9, in one embodiment of this application, the projected area S of the first water box 310 on its installed side wall and the length L of the line connecting the outermost ends of two adjacent heat exchange tubes 200 connected to the same first water box 310 in the first direction satisfy: S≥L×L.

[0069] Understandably, multiple heat exchange tubes 200 are arranged side by side at intervals in the first direction. In order to ensure sufficient installation space for the heat exchange tubes 200 and gap space between two adjacent heat exchange tubes 200 for high-temperature flue gas to pass through, the length L of the line connecting the outermost ends of two adjacent heat exchange tubes 200 connected to the same first water box 310 in the first direction will be greater than the diameter D1 of the heat exchange tube 200 in the third direction. In this embodiment, by setting S≥L×L, the projected area of ​​the first water box 310 on its side wall is further increased. When the height dimension of the first water box 310 in the second direction is constant, the volume of the first water box 310 is further increased, thereby achieving a better effect of reducing local resistance.

[0070] In one embodiment of this application, as shown in Figures 1, 3, 6 and 9, the heat exchanger further includes a cooling channel assembly (401 / 402 / 403) disposed on the side wall of the shell 100, the cooling channel assembly (401 / 402 / 403) including at least two cooling pipes arranged in parallel along a third direction; the heat exchanger further includes a third water box 330 disposed on one side wall of the shell 100 in a second direction, the third water box 330 connecting the cooling channel assembly (401 / 402 / 403) to one end of the heat exchange channel 201.

[0071] By providing a cooling channel assembly (401 / 402 / 403) on the side wall of the shell 100, and connecting the cooling channel assembly (401 / 402 / 403) to the heat exchange channel 201 via a third water box 330, water in the heat exchange channel 201 can flow through the cooling channel assembly (401 / 402 / 403), thereby achieving the purpose of cooling the side wall of the shell 100. The cooling channel assembly (401 / 402 / 403) includes at least two cooling pipes arranged in parallel along a third direction. These at least two cooling pipes are arranged in parallel along the flue gas flow direction and connected to the side wall of the heat exchange chamber B. 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. If at least two cooling pipes are connected in parallel, then the inlets of the at least two cooling pipes are connected to each other, and the outlets are connected to each other. The water entering the at least two cooling pipes from the inlet is at a lower temperature. Compared with the series connection, on the one hand, it increases the temperature difference between the water in the cooling pipe and the heat exchange chamber B, resulting in higher heat exchange efficiency. On the other hand, it can obtain the same heat exchange area on the wall as the series connection, while increasing the flow cross-sectional area, reducing water flow resistance, and increasing the flow rate.

[0072] By setting a third water box 330 to connect the heat exchange channel 201 and the cooling channel group (401 / 402 / 403), the third water box 330 is equivalent to a transfer water box for connecting series pipes to parallel pipes. This allows the water flowing out of the heat exchange channel 201 to be evenly distributed in the third water box 330 and then simultaneously enter at least two parallel cooling pipes, which can reduce water flow resistance and achieve better flow distribution.

[0073] Furthermore, as shown in Figures 1, 3, 6, and 9, the third water box 330 extends along a third direction. This design, on the one hand, increases the coverage area of ​​the third water box 330 on its side wall, increases the heat exchange area with the wall of the shell 100, and accelerates the cooling of the shell 100 wall; on the other hand, it can guide the water flowing from the relatively low heat exchange channel 201 upward to at least two parallel cooling pipes, achieving better flow distribution.

[0074] Furthermore, as shown in Figures 1, 3, 6, 7 and 9, a recess 331 is provided on one side of the third water box 330; in the third direction, the heat exchange tube 200 connected to the third water box 330 is located below the recess 331.

[0075] By providing a recess 331 on one side of the third water box 330, and with the heat exchange tube 200 located below the recess 331, a contraction and expansion tube effect is formed inside the third water box 330. Water flowing into the third water box 330 from the heat exchange tube 200 will be guided upward under the contraction tube effect, directing the water towards the cooling tubes (first cooling tube 401 and second cooling tube 402) located at a higher position. This ensures that sufficient water flow can circulate in the upper cooling tubes, preventing severe high-temperature vaporization in the upper cooling tubes under low flow conditions.

[0076] Specifically, as shown in Figures 1, 3, 6, 7 and 9, the cooling channel assembly (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. In the third direction, the recess 331 is located on the side of the second cooling pipe 402 away from the first cooling pipe 401.

[0077] 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.

[0078] 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.

[0079] 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 sets three cooling pipes side by side.

[0080] Furthermore, as shown in Figures 9 and 10, 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. 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 height distance between the ignition device 700 and the combustion component 600. It also cools the wall surface where the ignition device 700 is located, preventing it from deforming or loosening due to heat, thus ensuring the reliability of the ignition device 700's installation and extending its service life.

[0081] In one embodiment, the flow cross-sectional shape of the first cooling pipe 401 is circular; in another embodiment, the flow cross-sectional shape of the second cooling pipe 402 is circular; and in yet another embodiment, the flow cross-sectional shape of the third cooling pipe 403 is elliptical.

[0082] As shown in Figures 1, 3, 7, and 9, in the third direction, the recess 331 is located on the side of the second cooling pipe 402 away from the first cooling pipe 401. With this arrangement, the heights of both the first cooling pipe 401 and the second cooling pipe 402 are higher than the height of the recess 331. Thus, the recess 331 can guide the water in the third water box 330 to the first cooling pipe 401 and the second cooling pipe 402 located above the recess 331, thereby increasing the water flow in the first cooling pipe 401 and the second cooling pipe 402 and preventing high-temperature vaporization.

[0083] Understandably, the shape and structure of the recess 331 can be determined according to the actual situation, such as being arc-shaped, triangular, rectangular, or other shapes. In this embodiment, in the projection on the side wall where the third water box 330 is installed, the projected shape of the recess 331 is concave arc-shaped. This design makes the inner wall surface of the recess 331 smoothly transition. Compared with shapes with corner structures, the concave arc-shaped recess 331 can reduce the resistance to water flow and has a better flow guiding effect.

[0084] In practical applications, the specific height of the recess 331 can be determined according to the actual situation, as long as it ensures that the water flow in the third water box 330 is directed towards the upper first cooling pipe 401 and the second cooling pipe 402. The position of the recess 331 should not be too low or too high. If it is too low, the distance between the recess 331 and the upper first cooling pipe 401 and the second cooling pipe 402 will be too large, which may not achieve the effect of guiding water to the upper first cooling pipe 401 and the second cooling pipe 402. If it is too high, the distance between the recess 331 and the lower cooling channel will be too large, which may also not achieve the effect of guiding water to the upper first cooling pipe 401 and the second cooling pipe 402. Based on this, in this embodiment, the center of the recess 331 is at the same height as the center of the third cooling pipe 403, so that the height of the recess 331 is neither too high nor too low, which can achieve a better effect of guiding water to the upper first cooling pipe 401 and the second cooling pipe 402.

[0085] In one embodiment of this application, as shown in Figures 5 and 7, the third water box 330 and the first water box 310 are an integral structure.

[0086] In this embodiment, the third water box 330 and the first water box 310 can be integrally stamped from the same plate. This arrangement can reduce the complexity of manufacturing and improve production efficiency. Thus, it is possible to reduce local resistance loss on the basis of integral stamping of multiple water boxes.

[0087] Specifically, the heat exchanger also includes two mounting plates 300 disposed outside the two side walls of the shell 100 in the second direction. The first water box 310 and the third water box 330 are both formed by the mounting plates 300 protruding outwards in a direction away from the shell 100. In one embodiment, two mounting plates 300 are respectively disposed outside the third side wall 130 and the fourth side wall 140 of the shell 100. The first water box 310 and the third water box 330 are both formed by the corresponding mounting plates 300 protruding outwards. This allows the mounting plates 300 to be manufactured separately and then assembled with the third side wall 130 and the fourth side wall 140 respectively, ensuring the integrity of the third side wall 130 and the fourth side wall 140, improving the sealing of the heat exchange chamber B, and preventing the leakage of high-temperature flue gas. In one embodiment, the height of the first water box 310 and the second water box 320 protruding from the corresponding side wall in the second direction can be the same or different.

[0088] In one embodiment of this application, as shown in Figures 1 to 5, and Figures 7 and 8, the heat exchanger further includes two second water boxes 320 disposed on the two side walls of the shell 100 along the second direction. The second water boxes 320 are formed by the mounting plate 300 protruding outward in the direction away from the shell 100. Cooling channel groups (401 / 402 / 403) are provided on both side walls of the shell 100 along the first direction. The heat exchange channel 201, the third water box 330, one of the cooling channel groups (401 / 402 / 403), one second water box 320, another cooling channel group (401 / 402 / 403), and the other second water box 320 are connected in sequence. The heat exchange channel 201 is provided with an inlet 501, and the second water box 320 located downstream of the fluid is provided with an outlet 502.

[0089] Specifically, a second water box 320 is provided on both the third side wall 130 and the fourth side wall 140, and a cooling channel assembly (401 / 402 / 403) is provided on both the first side wall 110 and the second side wall 120. The heat exchange channel 201 is provided with an inlet 501, and the second water box 320 on the third side wall 130 is provided with an outlet 502. Thus, cold water enters from the inlet 501, flows through the heat exchange channel 201, the third water box 330, the cooling channel assembly (401 / 402 / 403) on the first side wall 110, the second water box 320 on the fourth side wall 140, the cooling channel assembly (401 / 402 / 403) on the second side wall 120, and the second water box 320 on the third side wall 130 in sequence, and then flows out from the outlet 502.

[0090] Understandably, the second water tank 320 is also formed by the mounting plate 300 protruding outward from the housing 100 outside the third side wall 130 and the fourth side wall 140. With this arrangement, the first water tank 310, the third water tank 330, and the second water tank 320 at the third side wall 130 can all be integrally stamped from the same mounting plate 300; the second water tank 320 and the first water tank 310 at the fourth side wall 140 can also be integrally stamped from the same mounting plate 300. This further simplifies the production process and improves production efficiency.

[0091] In one embodiment of this application, as shown in Figures 1 and 2, 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.

[0092] 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 321 recessed towards its corresponding sidewall to increase the structural strength of the second water box 320. In one embodiment, the reinforcing recess 321 of the second water box 320 can be recessed to fit snugly against its corresponding sidewall and fixed by welding.

[0093] In one embodiment of this application, as shown in Figures 1 to 4, the second water box 320 is provided with a protrusion 322 protruding toward the first water box 310 on its side along the first direction; in the third direction, the protrusion 322 is provided with the cooling pipe at the bottom of the cooling channel group (401 / 402 / 403).

[0094] In this embodiment, by providing protrusions 322 on both sides of the second water box 320 along the first direction, and these protrusions 322 protruding towards the first water box 310 in the third direction, they can smoothly communicate with the lowermost third cooling pipe 403 on the third side wall 130 and the fourth side wall 140, ensuring smooth water flow. Furthermore, the projection of the second water box 320 in the second direction can cover the third cooling pipe 403. Compared to using a pipe to connect the third cooling pipe 403, this embodiment can further reduce fluid resistance.

[0095] Furthermore, the first water boxes 310 located on both sides of the same sidewall are provided with relief recesses 311 corresponding to the protrusions 322 to avoid interference.

[0096] Furthermore, as shown in Figures 1 and 3, the lower surface of the outlet 502 is higher than the upper surface of the inlet 501. This design allows water to enter from a lower position and exit from a higher position, ensuring that the pipes through which the water flows are fully filled with water. This prevents the upper cooling pipe from being incompletely filled under low flow conditions, thus avoiding severe vaporization noise.

[0097] In one embodiment, as shown in Figures 3 and 4, 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. In this embodiment, the water outlet 502 is located on the upper edge of the second water box 320 on the third side wall 130, and the upper edge of the second water box 320 on the third side wall 130 is higher than the upper edge of the second water box 320 on the fourth side wall 140, as shown in the figure, h1 is greater than h3. This design allows the water outlet 502 to be in a higher position, thereby ensuring that the pipe through which the water flows is filled with water, preventing the first cooling pipe 401 from being incompletely filled under low flow conditions, and achieving the purpose of reducing vaporization noise.

[0098] In one embodiment, the upper edge of the second water box 320 with the outlet 502 is higher than the upper edge of the third water box 330. As shown in Figure 3, h1 is greater than h2. This design allows the outlet 502 to be in a higher position, thereby ensuring that the pipe through which the water flows is filled with water. This prevents the first cooling pipe 401 from being incompletely filled under low flow conditions, thus reducing vaporization noise.

[0099] 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 (401 / 402 / 403), and the diameter of the outlet 502 is larger than the inner diameter of the first cooling pipe 401.

[0100] In one embodiment of this application, as shown in Figures 9 and 10, the heat exchange tube 200 is an elliptical tube; the major axis of the heat exchange tube 200 is aligned with a third direction, and the minor axis of the heat exchange tube 200 is aligned with a first direction.

[0101] By setting the heat exchange tube 200 as an elliptical tube, the heat exchange area of ​​the heat exchange tube 200 is increased. At the same time, aligning the major axis of the heat exchange tube 200 with the flue gas flow direction can reduce the flow resistance of the high-temperature flue gas and improve the heat exchange efficiency.

[0102] 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.

[0103] 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.

[0104] 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 contains a heat exchange chamber. Multiple heat exchange tubes are arranged side-by-side in the heat exchange chamber along a first direction, with both ends of each tube extending through opposite side walls of the shell along a second direction; and Multiple first water boxes are respectively disposed on opposite side walls of the shell along the second direction, and 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; The length of the line connecting the outermost ends of two adjacent heat exchange tubes in the first direction is defined as L, the diameter of the heat exchange tube in the third direction is defined as D1, and the projected area of ​​the first water box on its installed side wall is defined as S, satisfying: S>L×D1; wherein the first direction, the second direction, and the third direction intersect each other.

2. The heat exchanger of claim 1, wherein, Satisfies: S≥L×L.

3. The heat exchanger of claim 1 or 2, wherein, The first water box has a square shape projected onto the side wall where it is installed.

4. The heat exchanger of any one of claims 1 to 3, wherein, The heat exchanger also includes a cooling channel assembly disposed on the side wall of the shell, the cooling channel assembly including at least two cooling pipes arranged in parallel along a third direction; The heat exchanger also includes a third water box disposed on one side wall of the shell in the second direction, the third water box connecting the cooling channel assembly to one end of the heat exchange channel.

5. The heat exchanger of claim 4, wherein, The third water box extends in a third direction.

6. The heat exchanger of claim 4 or 5, wherein, The third water box has a recessed portion on one side; in the third direction, the heat exchange tube connected to the third water box is located below the recessed portion.

7. The heat exchanger of claim 6, 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. In the third direction, the recess is located on the side of the second cooling pipe opposite to the first cooling pipe.

8. The heat exchanger of claim 6 or 7, wherein, In the projection on the side wall where the third water box is installed, the projected shape of the recess is a concave arc.

9. The heat exchanger of claim 7 or 8, wherein, The center of the recessed portion is at the same height as the center of the third cooling pipe.

10. The heat exchanger of any one of claims 7 to 9, 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.

11. The heat exchanger of any one of claims 4 to 10, wherein, The third water box is an integral structure with the first water box.

12. The heat exchanger of any one of claims 4 to 11, wherein, The heat exchanger also includes two mounting plates disposed on the outer side walls of the two sides of the shell in the second direction, and the first water box and the third water box are both formed by the mounting plates protruding outward in the direction away from the shell.

13. The heat exchanger of claim 12, wherein, The heat exchanger also includes two second water boxes disposed on the two side walls of the shell along the second direction, the second water boxes being formed by the mounting plate protruding outward in the direction away from the shell; The cooling channel assembly is provided on both sides of the housing along the first direction; The heat exchange channel, the third water box, one of the cooling channel groups, one of the second water boxes, another cooling channel group, and another second water box are connected in sequence. The heat exchange channel is provided with an inlet, and the second water box located downstream of the fluid is provided with an outlet.

14. The heat exchanger of claim 13, wherein, The lower surface of the outlet is higher than the upper surface of the inlet.

15. The heat exchanger as claimed in claim 13 or 14, 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 opposite second water box; and / or, the upper edge of the second water box with the outlet is higher than the upper edge of the third water box.

16. The heat exchanger of any one of claims 13 to 15, wherein, In the third direction, the upper surface of the water outlet is higher than the upper surface of the cooling channel assembly.

17. The heat exchanger according to any one of claims 13 to 16, wherein, The second water box has a protrusion on its side along the first direction that protrudes toward the first water box; In the third direction, the convex hull corresponds to the cooling pipe at the bottom of the cooling channel group.

18. The heat exchanger as claimed in claim 17, wherein, The first water boxes located on both sides of the same side wall are provided with avoidance recesses corresponding to the convex bulge.

19. The heat exchanger according to any one of claims 1 to 18, wherein, The heat exchange tube is an elliptical tube; the major axis of the heat exchange tube is aligned with a third direction, and the minor axis of the heat exchange tube is aligned with a first direction.

20. A gas-fired water heater, wherein, The gas water heater includes a heat exchanger as described in any one of claims 1 to 19.

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