Reducer joint assembly and double-layer smoke tube

Abstract

The utility model belongs to the technical field of hot water equipment, and particularly discloses a reducer union assembly and a double-layer smoke tube, the reducer union assembly comprises an inner joint and an outer joint, the outer joint is fixedly sleeved on the inner joint, a first channel is formed by the outer joint and the inner joint, the outer joint comprises a first connecting part, a first reducing part and a second connecting part which are arranged in sequence, the outer diameter of the first connecting part is D, the outer diameter of the second connecting part is d1, and D / d1 is larger than or equal to 1.1 and smaller than or equal to 1.45. The double-layer smoke tube and the gas water heater each comprise the reducer union assembly. The double-layer smoke pipe applying the reducer union assembly can penetrate through an original mounting hole of a wall body or a window body while the air inlet efficiency is guaranteed, and the mounting efficiency is high.

Description

Technical Field

[0001] This utility model relates to the field of hot water equipment technology, and in particular to a reducing connector assembly and a double-layer flue. Background Technology

[0002] In recent years, with economic development and scientific and technological progress, people's living standards have greatly improved, and gas water heaters have begun to enter thousands of households. However, ordinary gas water heaters extract oxygen from the room for combustion during operation, thereby reducing the indoor oxygen content and posing a potential threat to users' lives. Therefore, the application of balanced flue gas water heaters is becoming increasingly widespread.

[0003] Balanced flue gas water heaters use a double-layer flue design to draw in outdoor air for combustion, while exhaust gases are discharged outdoors through the inner flue, avoiding waste of indoor space. To simplify installation, the double flues pass through existing mounting holes in the wall or window, and the outer flue's diameter cannot exceed these holes. This results in low air intake efficiency, poor combustion performance, and potential safety risks for balanced flue gas water heaters. Utility Model Content

[0004] One of the technical problems solved by this utility model is to provide a reducing connector assembly that allows the double-layer flue pipe to pass through the original mounting holes on the wall or window, and has high air intake efficiency.

[0005] The second technical problem solved by this utility model is to provide a double-layer flue that can be installed without additional hole enlargement and has high air intake efficiency.

[0006] The first technical problem mentioned above is solved by the following technical solution:

[0007] A reducing connector assembly includes an inner connector and an outer connector. The outer connector is fixedly sleeved on the inner connector and forms a first channel between the outer connector and the inner connector. The outer connector includes a first connecting part, a first reducing part and a second connecting part arranged in sequence. Let the outer diameter of the first connecting part be D and the outer diameter of the second connecting part be d1, where 1.1≤D / d1≤1.45.

[0008] Compared with the prior art, the reducing connector assembly of this utility model has the following advantages: by changing the size of the outer flue pipe through the reducing outer connector, the double-layer flue pipe can be passed through a smaller mounting hole to the outside without the need for hole enlargement, thus improving installation convenience. Furthermore, compared with using an outer flue pipe with the same diameter as the mounting hole, the air intake efficiency is higher. More importantly, the outer diameters of the first and second connecting parts of the outer connector are limited to no more than 1.45, avoiding excessively large connecting outer pipe sizes and reducing the manufacturing and transportation costs of the double-layer flue pipe.

[0009] In one embodiment, the outer diameter d2 of the inner connector is between 43mm and 46mm, and d1 is between 60mm and 63mm.

[0010] In one embodiment, the first variable diameter portion is configured as a tapered shape with its outer diameter gradually decreasing from one end connected to the first connecting portion to the other end, and the angle between the generatrix of the first variable diameter portion and the axis of the first variable diameter portion is α, where 35° < α < 70°.

[0011] In one embodiment, the inner connector protrudes from the outer connector.

[0012] In one embodiment, the inner connector protrudes from the outer connector by a length L between 10mm and 15mm.

[0013] The second technical problem mentioned above is solved by the following technical solution:

[0014] A double-layer flue, including the reducing connector assembly described in any one of the above claims, further includes an insert pipe assembly and a connecting pipe assembly. The insert pipe assembly includes an insert outer pipe connected to the outer connector and an insert inner pipe connected to the inner connector, with a second channel forming between the insert inner pipe and the insert outer pipe communicating with the first channel. The connecting pipe assembly includes a connecting inner pipe and a connecting outer pipe, with the connecting outer pipe fixedly sleeved on the connecting inner pipe and connected to the first connecting part. The connecting inner pipe is connected to the inner connector, and a third channel forming between the connecting outer pipe and the connecting inner pipe communicating with the first channel is formed. The outer diameter of the connecting outer pipe is larger than the outer diameter of the insert outer pipe.

[0015] Compared with the prior art, the double-layer flue pipe of this utility model has the following advantages: The double-layer flue pipe changes the outer diameter of the outer flue pipe through an external connector, allowing the double-layer flue pipe to pass through the original smaller mounting hole without additional hole enlargement, thus improving the installation convenience of the flue pipe. Compared with using an outer flue pipe with the same diameter as the mounting hole, the air intake efficiency is higher. Furthermore, the outer diameters of the first and second connecting parts of the external connector are limited to no more than 1.45, avoiding excessively large local dimensions of the outer flue pipe and reducing the manufacturing and transportation costs of the double-layer flue pipe.

[0016] In one embodiment, the connecting inner tube includes a first inner bend, the connecting outer tube includes a first outer bend, the first outer bend is connected to the first connecting part and fixedly sleeved on the first inner bend, and the first inner bend is connected to the inner connector.

[0017] In one embodiment, the connecting pipe assembly includes a second bend, a third bend, and a first straight pipe section. Both ends of the second bend extend horizontally. The second bend connects the reducing connector assembly and the first straight pipe section. The end of the first straight pipe section away from the second bend is connected to the third bend. The third bend extends horizontally at one end connected to the first straight pipe section and vertically at the other end.

[0018] In one embodiment, the connecting pipe assembly includes a second straight pipe section, a third straight pipe section, and a fourth bend pipe section, the second straight pipe section extending vertically, the fourth bend pipe section connecting the second straight pipe section and the third straight pipe section, and the third straight pipe section also connecting to a reducing connector assembly.

[0019] In one embodiment, the double-layer flue further includes an inlet / outlet connector assembly for connecting to a gas water heater. The inlet / outlet connector assembly further includes an outlet connector and an inlet connector. The inlet connector is fixedly sleeved on the outlet connector and connected to the end of the connecting outer pipe away from the outer connector. A fourth channel is formed between the inlet connector and the outlet connector, communicating with the third channel. The outlet connector includes a third connecting part, a second reducing part, and a fourth connecting part arranged in sequence. The third connecting part is connected to the end of the connecting inner pipe away from the inner connector, and the outer diameter of the third connecting part is smaller than the outer diameter of the fourth connecting part.

[0020] In one embodiment, the air intake connector includes a fifth connecting part, a third variable diameter part and a sixth connecting part arranged in sequence. The fifth connecting part is connected to the connecting outer pipe, and the third variable diameter part is configured as a tapered shape with its outer diameter gradually increasing from the end connected to the fifth connecting part to the end connected to the sixth connecting part. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the structure of the reducing joint assembly provided in the embodiments of this utility model;

[0022] Figure 2 This is a cross-sectional view of the reducing connector assembly provided in the embodiments of this utility model;

[0023] Figure 3 This is a three-dimensional structural diagram of the external connector provided in the embodiments of this utility model;

[0024] Figure 4 This is a front view of the external connector provided in an embodiment of this utility model;

[0025] Figure 5 This is a schematic diagram of the exploded structure of a double-layer smoke pipe provided in one embodiment of the present invention;

[0026] Figure 6This is a schematic diagram of the exploded structure of a double-layer smoke pipe provided in another embodiment of the present invention;

[0027] Figure 7 This is a schematic diagram of the exploded structure of the double-layer smoke pipe provided in another embodiment of the present invention;

[0028] Figure 8 This is a cross-sectional view of the insertion tube assembly in an embodiment of this utility model;

[0029] Figure 9 This is a cross-sectional view of the gas water heater in an embodiment of this utility model;

[0030] Figure 10 for Figure 9 An enlarged view of point A in the middle.

[0031] Label Explanation:

[0032] 10. Reducing connector assembly; 11. External connector; 111. First connecting part; 112. Second connecting part; 113. First reducing part; 12. Internal connector;

[0033] 20. Insertion tube assembly; 21. Connecting pipe section; 211. Connecting outer pipe; 212. Connecting inner pipe; 22. Tail pipe section; 221. Tail pipe outer pipe; 2211. Air inlet; 2212. Air outlet; 222. Tail pipe inner pipe;

[0034] 30. Connecting pipe assembly; 31. First bend pipe section; 32. Second bend pipe section; 33. Third bend pipe section; 34. Fourth bend pipe section; 35. First straight pipe section; 36. Second straight pipe section; 37. Third straight pipe section;

[0035] 40. Air inlet / outlet connector assembly; 41. Air inlet connector; 411. Fifth connecting part; 412. Sixth connecting part; 413. Third reducing part; 42. Air outlet connector; 421. Third connecting part; 422. Fourth connecting part; 423. Second reducing part;

[0036] 50. Water heater body; 50a. Air inlet; 50b. Air outlet. Detailed Implementation

[0037] 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 some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0038] In the description of this application, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0039] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0040] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0041] refer to Figures 1-10 As shown, an embodiment of this utility model proposes a reducing connector assembly 10, a double-layer flue, and a gas water heater. The gas water heater includes a water heater body 50 and a double-layer flue. The water heater body 50 has an air inlet 50a and an air outlet 50b arranged coaxially. The double-layer flue includes an outer flue connected to the air inlet 50a and an inner flue connected to the air outlet 50b, with the outer flue fixedly sleeved on the inner flue. The double-layer flue is used to discharge the flue gas in the gas water heater to the outside while simultaneously drawing outdoor air into the water heater body 50.

[0042] refer to Figures 5-8As shown, the double-layer flue includes a connecting pipe assembly 30, a reducing connector assembly 10, and a through-pipe assembly 20. The connecting pipe assembly 30 is connected to the water heater body 50 and includes an inner connecting pipe and an outer connecting pipe. The inner connecting pipe is connected to the air outlet 50b, and the outer connecting pipe is fixedly sleeved on the inner connecting pipe and connected to the air inlet 50a. A third channel is formed between the outer connecting pipe and the inner connecting pipe. The reducing connector assembly 10 connects the connecting pipe assembly 30 and the through-pipe assembly 20. The through-pipe assembly 20 can pass through mounting holes opened in walls or windows. The through-pipe assembly 20 includes an inner through-pipe and an outer through-pipe. The outer through-pipe is fixedly sleeved on the inner through-pipe and forms a second channel between them. The reducing connector assembly 10 further includes an outer connector 11 and an inner connector 12. One end of the inner connector 12 is connected to the connecting inner pipe, and the other end is connected to the inserting inner pipe. The outer connector 11 is fixedly sleeved on the inner connector 12, forming a first channel between them. One end of the outer connector 11 is connected to the connecting outer pipe, and the other end is connected to the inserting outer pipe. The outer diameter of the connecting outer pipe is larger than the outer diameter of the inserting outer pipe. The connecting inner pipe, the inner connector 12, and the inserting inner pipe are all internal smoke pipes, and the connecting outer pipe, the outer connector 11, and the inserting outer pipe are all external smoke pipes. An exhaust channel is formed inside the internal smoke pipe, and an air intake channel is formed between the internal smoke pipe and the external smoke pipe. The first channel, the second channel, and the third channel are all air intake channels.

[0043] refer to Figures 1-4 As shown, in order to directly utilize the existing mounting holes on the wall or window, the external connector 11 includes a first connecting part 111, a first reducing part 113, and a second connecting part 112 arranged sequentially. The first connecting part 111 connects to the connecting outer tube, the second connecting part 112 connects to the inserting outer tube, and the first reducing part 113 is disposed between the first connecting part 111 and the second connecting part 112. Let the outer diameter of the first connecting part 111 be D, and the outer diameter of the second connecting part 112 be d1, where 1.1 ≤ D / d1 ≤ 1.45, for example, D / d1 = 1.1, D / d1 = 1.2, D / d1 = 1.3, and D / d1 = 1.45. When D / d1 = 1.45, the air intake efficiency is the highest; when D / d1 = 1.1, the manufacturing cost is the lowest while maintaining air intake efficiency.

[0044] The aforementioned reducing connector assembly 10, double-layer flue pipe, and gas water heater utilize the external connector 11 to change the outer diameter of the outer flue pipe. This allows the outer flue pipe to maintain a large effective flow area when connected to the air inlet 50a, ensuring air intake efficiency. Conversely, the outer diameter decreases when passing through the mounting hole, allowing for smooth passage and improving installation convenience. It is worth emphasizing that if the value of D / d1 is too large, with the second connecting part 112 remaining unchanged, it will result in an excessively large diameter of the connecting outer pipe of the external connector 11, increasing transportation and processing costs. Therefore, in this embodiment, D / d1 is limited to between 1.1 and 1.45, satisfying the requirements of not enlarging the mounting hole and ensuring air intake efficiency, while also avoiding increased manufacturing and transportation costs.

[0045] Let the diameter of the mounting hole on the wall or window be R, where R-3≤d1≤R, to maximize the effective flow area of ​​the air intake channel while ensuring the double-layer flue can pass smoothly through the mounting hole. For example, if the mounting hole on the wall or window is 63mm, then d1 is limited to between 60mm and 63mm, such as 60mm, 61mm, 62mm, or 63mm. A d1 of 63mm results in the highest air intake efficiency, while a d1 of 60mm makes it easier to pass through the mounting hole. To improve the balance between the air intake efficiency of the air intake channel and the exhaust efficiency of the exhaust channel, the outer diameter d2 of the inner flue is between 43mm and 46mm. For example, d2 is 43mm, 44mm, 45mm, or 46mm. Specifically, the outer diameter of the connecting inner tube, the inner connector 12, and the inserting inner tube is all d2. Preferably, considering the manufacturing difficulty, the connecting inner tube, the inner connector 12, and the inserting inner tube are all manufactured using standard 45mm pipe fittings. In summary, by defining a reasonable size chain with a certain relationship between D, d1, and d2, considerations of air intake efficiency, smoke exhaust efficiency, flue volume, and cost can be taken into account.

[0046] For ease of connection, one end of the inner connector 12 is either narrowed or flared to allow for insertion into the inner tube. Similarly, one end of the inner tube inserted into the inner connector 12 is either narrowed or flared to allow for insertion into the inner connector 12. Narrowing or flaring are common stamping processes and will not be described in detail here.

[0047] Continue to refer to Figure 4As shown, the first variable diameter section 113 is configured as a cone with its outer diameter gradually decreasing from one end connected to the first connecting section 111 to the other end. Let the angle between its generatrix and the axis be α. If the angle α is too large, it will cause vortices to be generated in the airflow at the connection between the first variable diameter section 113 and the first connecting section 111 and the connection between the first variable diameter section 113 and the second connecting section 112, which will affect the air intake efficiency. If the angle α is too small, it will cause the length of the first variable diameter section 113 to be too long. When the water heater body 50 is assembled into the wall or window, the variable diameter connector assembly 10 is prone to interference with the wall or window. In one embodiment, 35° < α < 70°, for example, α is 40°, 45°, 50° or 60°.

[0048] Specifically, the inner tube and inner connector 12, the inner connector 12 and the inserted inner tube, the outer tube and outer connector 11, and the outer connector 11 and the inserted outer tube are all connected by insertion to improve assembly stability. To further enhance stability, adjacent tubes can be welded or bolted together after the insertion. For example, both the outer connector 11 and the inserted outer tube have connection holes for fasteners to pass through, allowing the fasteners to pass radially through them for further connection. It is understood that since the inserted outer tube is fixedly fitted onto the inserted inner tube, assembly stability can be improved simply by further defining the outer connector 11 and the inserted outer tube.

[0049] In one embodiment, the inner connector 12 is first assembled onto the inner connecting tube, and then the outer connecting tube equipped with the outer connector 11 is sleeved onto the inner connecting tube. To reduce the assembly difficulty of the reducing connector assembly 10 and the insertion tube assembly 20, the inner connector 12 protrudes from the outer connector 11. Therefore, when assembling the reducing connector assembly 10 and the insertion tube assembly 20, the inner insertion tube can be assembled onto the inner connector 12 first to achieve positioning, and then the outer insertion tube can be assembled.

[0050] For example, the inner connector 12 protrudes from the outer connector 11. The protrusion length of the inner connector 12 is L, which is between 10mm and 15mm. For example, L is 10mm, 11mm, 12mm, 13mm, 14mm, or 15mm, so as not to significantly increase the manufacturing cost of the inner connector 12 while meeting assembly requirements.

[0051] The connecting pipe assembly 30 can be a bent pipe structure or a combination of bent pipe and straight pipe structures.

[0052] refer to Figure 5As shown, in one embodiment, the connecting pipe assembly 30 includes a first bend section 31. One end of the first bend section 31 is connected to the reducing connector assembly 10 and extends horizontally, while the other end extends vertically and is connected to the water heater body 50. Specifically, the first bend section 31 includes a first inner bend and a first outer bend fixedly sleeved on the first inner bend. The first outer bend is for connecting the outer pipe, and the first inner bend is for connecting the inner pipe.

[0053] refer to Figure 6 As shown, in another embodiment, the connecting pipe assembly 30 includes a second bend section 32, a third bend section 33, and a first straight section 35. Both ends of the second bend section 32 extend horizontally and connect the reducing connector assembly 10 and the first straight section 35. The end of the first straight section 35 away from the second bend section 32 is connected to the third bend section 33, and the end of the third bend section 33 connected to the first straight section 35 extends horizontally, while the other end extends vertically. Specifically, the second bend section 32 further includes a second inner bend and a second outer bend fixedly sleeved on the second inner bend. The third bend section 33 includes a third inner bend and a third outer bend fixedly sleeved on the third inner bend. The first straight section 35 further includes a first inner straight pipe and a first outer straight pipe fixedly sleeved on the first inner straight pipe. The second outer bend, the third outer bend, and the first outer straight pipe constitute the connecting outer pipe, and the second inner bend, the third inner bend, and the first inner straight pipe constitute the connecting inner pipe.

[0054] refer to Figure 7 As shown, in another embodiment, the connecting pipe assembly 30 includes a second straight pipe section 36, a third straight pipe section 37, and a fourth bend pipe section 34. The second straight pipe section 36 extends vertically, and the fourth bend pipe section 34 connects the second straight pipe section 36 and the third straight pipe section 37. The third straight pipe section 37 is also connected to the reducing connector assembly 10. Specifically, the second straight pipe section 36 includes a second inner straight pipe and a second outer straight pipe fixedly sleeved on the second inner straight pipe; the third straight pipe section 37 includes a third inner straight pipe and a third outer straight pipe fixedly sleeved on the third inner straight pipe; and the fourth bend pipe section 34 includes a fourth inner bend pipe and a fourth outer bend pipe fixedly sleeved on the fourth inner bend pipe. The second outer straight pipe, the third outer straight pipe, and the fourth outer bend pipe constitute the connecting outer pipe, and the second inner straight pipe, the third inner straight pipe, and the fourth inner bend pipe constitute the connecting inner pipe.

[0055] refer to Figure 5 and Figure 6As shown, in order to discharge flue gas through the exhaust pipe, the water heater body 50 includes a fan. In one embodiment, the fan still adopts the specifications used in ordinary gas water heaters to meet the exhaust requirements. The specifications of the fan used in ordinary gas water heaters are adapted to the diameter of the mounting hole. Obviously, at this time, the outer diameter of the fan outlet is larger than the outer diameter of the inner flue. Therefore, the double-layer flue also includes an exhaust connector 42. The exhaust connector 42 is connected to the outlet end of the fan and the inner pipe. The outlet end of the fan is the exhaust port 50b. The exhaust connector 42 includes a third connecting part 421, a second reducing part 423, and a fourth connecting part 422 arranged in sequence. The third connecting part 421 is connected to the inner pipe, and the fourth connecting part 422 is connected to the outlet end of the fan. The outer diameter of the third connecting part 421 is smaller than the outer diameter of the fourth connecting part 422. The second reducing part 423 is set as a cone with an outer diameter that gradually increases from one end connected to the third connecting part 421 to the other end.

[0056] Based on this, the double-layer flue also includes an air inlet connector 41 fixedly sleeved on the air outlet connector 42. A fourth channel is formed between the air inlet connector 41 and the air outlet connector 42, which is also an air inlet channel. The air inlet connector 41 includes a fifth connecting part 411, a third reducing part 413, and a sixth connecting part 412 arranged sequentially. The fifth connecting part 411 connects to the outer pipe, and the sixth connecting part 412 connects to the top wall of the water heater body 50 and surrounds the air inlet 50a therein. The third reducing part 413 is set as a cone with an outer diameter that gradually increases from the end connected to the fifth connecting part 411 to the end connected to the sixth connecting part 412, so as to avoid the effective flow area of ​​the air inlet channel connecting to the air inlet 50a being too small, which would affect the air intake efficiency.

[0057] Specifically, the end of the air outlet connector 42 away from the connecting inner pipe protrudes from the air inlet connector 41 to connect to the fan located inside the outer casing of the water heater body 50.

[0058] In one embodiment, the angle between the generatrix of the second variable diameter section 423 and the axis is the same or similar to the angle between the generatrix of the third variable diameter section 413 and the axis, so as to improve the air intake efficiency while avoiding excessive enlargement of the size of the air intake 50a, which would affect the thickness of the water heater body 50.

[0059] refer to Figure 8 As shown, to reduce the transportation cost of the insertion pipe assembly 20 and to flexibly adapt to different installation environments, both the insertion outer pipe and the insertion inner pipe are segmented. The insertion inner pipe includes a tail pipe inner pipe 222 and at least one connecting inner pipe 212, with the tail pipe inner pipe 222 located at the end of the connecting inner pipe 212 away from the reducing connector assembly 10. The insertion outer pipe includes a tail pipe outer pipe 221 and at least one connecting outer pipe 211, with the connecting outer pipe 211 correspondingly sleeved on the connecting inner pipe 212, and the tail pipe outer pipe 221 sleeved on the tail pipe inner pipe 222.

[0060] To reduce on-site assembly difficulty, the outer connecting pipe 211 is pre-fitted onto the inner connecting pipe 212 to form the connecting pipe section 21 before leaving the factory, and the outer tail pipe 221 is pre-fitted onto the inner tail pipe 222 to form the tail pipe section 22. During on-site assembly, simply connect the inner tail pipe 222 to the inner connecting pipe 212 and the outer tail pipe 221 to the outer connecting pipe 211. Based on this, the end of the inner connecting pipe 212 furthest from the reducing connector assembly 10 protrudes from the outer connecting pipe 211 to further reduce assembly difficulty.

[0061] Specifically, the outer tube 221 of the tailpipe has multiple air intake holes 2211 that connect to the air intake channel. In order to allow air to enter from all circumferential parts of the outer tube 221, multiple air intake holes 2211 are arranged at intervals along the circumference of the outer tube 221 to form groups of air intake holes 2211. At the same time, multiple groups of air intake holes 2211 are arranged at intervals along the axial direction of the outer tube 221 to improve air intake efficiency.

[0062] The outer tube 221 of the tailpipe is also provided with multiple air outlets 2212 that connect to the exhaust channel. The air outlets 2212 are located on the outer tube 221 of the tailpipe on the side away from the air inlet 2211. A blocking ring is provided in the air inlet channel between the air inlet 2211 and the air outlet 2212 to prevent the flue gas discharged through the air outlet 2212 from flowing back to the water heater body 50 through the air inlet channel.

[0063] In the specific implementation of the above embodiments, the technical features can be combined in any non-contradictory way. For the sake of brevity, not all possible combinations of the above technical features are described. However, as long as the combination of these technical features is not contradictory, it should be considered to be within the scope of this specification.

[0064] The specific embodiments described above are merely illustrative of several implementations of this utility model, and while the descriptions are detailed, they should not be construed as limiting the scope of this utility model patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this utility model, and these all fall within the protection scope of this utility model. Therefore, the protection scope of this utility model patent should be determined by the appended claims.

Claims

1. A reducing joint assembly, characterized in that, include: Internal connector (12); An outer connector (11) is fixedly sleeved on the inner connector (12) and forms a first channel between the inner connector (12). The outer connector (11) includes a first connecting part (111), a first variable diameter part (113), and a second connecting part (112) arranged in sequence. Let the outer diameter of the first connecting part (111) be D, and the outer diameter of the second connecting part (112) be d1, where 1.1 < D / d1 ≤ 1.

45.

2. The reducing joint assembly according to claim 1, characterized in that, The outer diameter d2 of the inner connector (12) is between 43mm and 46mm, and d1 is between 60mm and 63mm.

3. The reducing joint assembly according to claim 1, characterized in that, The first variable diameter section (113) is configured as a tapered shape with its outer diameter gradually decreasing from one end connected to the first connecting section (111) to the other end. Let the angle between the generatrix of the first variable diameter section (113) and the axis of the first variable diameter section (113) be α, where 35° < α < 70°.

4. The reducing joint assembly according to claim 1, characterized in that, The inner connector (12) protrudes from the outer connector (11).

5. The reducing joint assembly according to claim 4, characterized in that, The length L of the inner connector (12) protruding from the outer connector (11) is between 10mm and 15mm.

6. A double-layered smoke pipe, characterized in that, The assembly includes the reducing connector assembly as described in any one of claims 1-5, and further includes an insert tube assembly (20) and a connecting tube assembly (30). The insert tube assembly (20) includes an insert outer tube connected to the outer connector (11) and an insert inner tube connected to the inner connector (12). A second channel communicating with the first channel is formed between the insert inner tube and the insert outer tube. The connecting tube assembly (30) includes a connecting inner tube and a connecting outer tube. The connecting outer tube is fixedly sleeved on the connecting inner tube and connected to the first connecting part (111). The connecting inner tube is connected to the inner connector (12). A third channel communicating with the first channel is formed between the connecting outer tube and the connecting inner tube. The outer diameter of the connecting outer tube is larger than the outer diameter of the insert outer tube.

7. The double-layer smoke pipe according to claim 6, characterized in that, The inner connecting tube includes a first inner bend, and the outer connecting tube includes a first outer bend. The first outer bend is connected to the first connecting part (111) and is fixedly sleeved on the first inner bend. The first inner bend is connected to the inner connector.

8. The double-layer smoke pipe according to claim 6, characterized in that, The connecting pipe assembly (30) includes a second bend (32), a third bend (33), and a first straight pipe (35). Both ends of the second bend (32) extend horizontally. The second bend (32) connects the reducing connector assembly and the first straight pipe (35). The end of the first straight pipe (35) away from the second bend (32) is connected to the third bend (33). The third bend (33) extends horizontally at one end connected to the first straight pipe (35) and vertically at the other end.

9. The double-layer smoke pipe according to claim 6, characterized in that, The connecting pipe assembly (30) includes a second straight pipe section (36), a third straight pipe section (37), and a fourth bend pipe section (34). The second straight pipe section (36) extends vertically, and the fourth bend pipe section (34) connects the second straight pipe section (36) and the third straight pipe section (37). The third straight pipe section (37) is also connected to the reducing joint assembly.

10. The double-layered flue pipe according to any one of claims 6-9, characterized in that, The double-layer flue also includes an inlet / outlet connector assembly (40) installed on the gas water heater. The inlet / outlet connector assembly (40) includes an outlet connector (42) and an inlet connector (41). The inlet connector (41) is fixedly sleeved on the outlet connector (42) and connected to the end of the connecting outer pipe away from the outer connector (11). The inlet connector (41) and the outlet connector (42) form a fourth channel communicating with the third channel. The outlet connector (42) includes a third connecting part (421), a second reducing part (423), and a fourth connecting part (422) arranged in sequence. The third connecting part (421) is connected to the end of the connecting inner pipe away from the inner connector (12). The outer diameter of the third connecting part (421) is smaller than the outer diameter of the fourth connecting part (422).

11. The double-layer smoke pipe according to claim 10, characterized in that, The air intake connector (41) includes a fifth connecting part (411), a third variable diameter part (413) and a sixth connecting part (412) arranged in sequence. The fifth connecting part (411) is connected to the connecting outer pipe. The third variable diameter part (413) is configured as a cone with an outer diameter that gradually increases from the end connected to the fifth connecting part (411) to the end connected to the sixth connecting part (412).

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