Cover body assembly and heat exchanger

Abstract

The utility model discloses a cover body assembly which comprises a cover body, the cover body is provided with a gas inlet channel and a fuel gas channel, the two ends of the fuel gas channel are correspondingly provided with a gas inlet and a gas outlet, the gas inlet is communicated with the gas inlet channel, and the gas outlet is used for being communicated with a combustion cylinder. Wherein the fuel gas channel is provided with at least one section of narrowing part, the cross sectional area of the narrowing part is smaller than that of the fuel gas channel, and / or the fuel gas channel is provided with at least one section of expansion part, and the cross sectional area of the expansion part is larger than that of the fuel gas channel. Therefore, the change of acoustic impedance can be caused in the acoustic propagation process, and the reflection and interference phenomena of sound waves are generated, that is, the noise generated in the rapid flowing process of fuel gas can be reflected, interfered and the like at the narrowing part or the expansion part, so that the noise generated in the use process of the heat exchanger can be reduced. In addition, the utility model further discloses the heat exchanger with the cover body assembly.

Description

Technical Field

[0001] This utility model relates to the field of heat exchange technology, and in particular to a cover assembly and a heat exchanger. Background Technology

[0002] In existing technologies, heat exchangers used in boilers or wall-hung boilers typically include a shell and a cover assembly. The shell has a heat exchange chamber and an opening connected to the heat exchange chamber. Heat exchange tubes are installed inside the heat exchange chamber. The cover assembly covers the opening and seals the heat exchange chamber. The cover assembly has an air inlet channel and a gas passage connected to the air inlet channel. A combustion chamber is also installed inside the heat exchange chamber and is connected to the gas passage. The peripheral wall of the combustion chamber has multiple micropores. During use, gas can enter the combustion chamber through the air inlet channel and the gas passage, and then be ejected at high speed from the micropores on the peripheral wall of the combustion chamber. An ignition needle is located on the outside of the combustion chamber to ignite and burn the gas flowing out of the micropores. Thus, the gas can burn in the heat exchange chamber and heat the heat exchange tubes.

[0003] However, when the gas is ejected at high speed from the micro-holes on the periphery of the combustion chamber, friction is generated between the high-speed gas and the walls of the micro-holes, which in turn generates noise. At the same time, the outer surface of the combustion chamber will vibrate at a certain frequency. When this vibration frequency resonates with other components of the boiler, it will also generate resonance noise, which seriously affects the user experience. Utility Model Content

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention proposes a cover assembly that can effectively reduce the noise generated at the combustion chamber.

[0005] This utility model also proposes a heat exchanger having the above-mentioned cover assembly.

[0006] According to an embodiment of the present invention, a cover assembly includes: a cover body, having an air inlet channel and a gas passage, wherein an air inlet and an air outlet are correspondingly provided at both ends of the gas passage, the air inlet being connected to the air inlet channel, and the air outlet being used to connect to a combustion chamber; wherein the gas passage has at least one narrowing section, the cross-sectional area of ​​the narrowing section being smaller than the cross-sectional area of ​​the gas passage, and / or the gas passage has at least one expanding section, the cross-sectional area of ​​the expanding section being larger than the cross-sectional area of ​​the gas passage.

[0007] The cover assembly according to the embodiments of the present utility model has at least the following beneficial effects:

[0008] In the cover assembly of this utility model embodiment, by providing at least one narrowing section and / or expansion section in the gas passage, since the cross-sectional area of ​​the narrowing section is smaller than the cross-sectional area of ​​the gas passage, and the cross-sectional area of ​​the expansion section is larger than the cross-sectional area of ​​the gas passage, the cross-sectional area of ​​the gas passage will change abruptly at the narrowing section or the expansion section. This can cause a change in acoustic impedance during sound propagation, thereby generating sound wave reflection and interference phenomena. This ensures that the noise generated at the combustion chamber can propagate into the gas passage and undergo reflection and interference at the narrowing section, thereby effectively reducing the noise generated during the use of the heat exchanger and improving the user experience.

[0009] According to some embodiments of the present invention, the air intake channel is disposed on the cover and extends outward relative to the cover, and the cross-sectional area of ​​the air inlet is smaller than the cross-sectional area of ​​the air intake channel.

[0010] According to some embodiments of the present invention, the gas passage has at least two narrowing sections, and all the narrowing sections are arranged at intervals.

[0011] According to some embodiments of the present invention, the inner wall of the gas passage is provided with a first narrowing structure corresponding to at least one set of narrowing portions. The first narrowing structure includes at least one first protrusion, which protrudes from the inner wall of the gas passage and forms the side wall of the narrowing portion.

[0012] According to some embodiments of the present invention, the first narrowing structure includes two oppositely arranged first protrusions, the two first protrusions being correspondingly disposed on two opposite sidewalls of the gas passage, and the narrowing portion being located between the corresponding two first protrusions.

[0013] According to some embodiments of the present invention, a guide plate is provided inside the cover, and the gas passage is formed by the guide plate and the inner peripheral wall of the cover. In the first narrowing structure, one of the first protrusions is provided on the guide plate, and the other first protrusion is provided on the peripheral wall of the cover and arranged opposite to the guide plate.

[0014] According to some embodiments of this utility model, the cover includes a cover body and a sealing plate. The cover body has a gas chamber and an opening communicating with the gas chamber. The sealing plate is installed on the cover body and blocks the opening. The guide plate is disposed on the inner wall of the gas chamber and abuts against the sealing plate. The gas passage is formed by the cover body, the sealing plate and the guide plate surrounding and defining each other. The air inlet and the air inlet passage are both disposed on the cover body. The air outlet is disposed on the sealing plate. The combustion cylinder can be installed on the sealing plate and communicates with the air outlet.

[0015] According to some embodiments of the present invention, the inner wall of the gas passage is provided with a second narrowing structure corresponding to at least one set of narrowing portions. The second narrowing structure includes at least one second protrusion. The second protrusion protrudes from the inner wall of the gas chamber and abuts against the sealing plate. The second protrusion is spaced apart from the guide plate and defines the narrowing portion. The second protrusion has a first mounting hole for mounting an ignition needle. The sealing plate has a second mounting hole corresponding to the first mounting hole. The ignition needle can pass through the second mounting hole.

[0016] According to some embodiments of the present invention, the sealing plate is provided with at least one first reinforcing rib, the first reinforcing rib protruding toward the gas passage, and at least one first reinforcing rib is located within the narrowing portion.

[0017] The heat exchanger according to an embodiment of the present invention is provided with a cover assembly of any of the above embodiments.

[0018] The heat exchanger according to the embodiments of the present invention has at least the following beneficial effects:

[0019] By employing the cover assembly of any of the above embodiments, at least one narrowing section and / or at least one expanding section are provided in the gas passage, allowing the cross-sectional area of ​​the gas passage to undergo abrupt changes. This results in a change in acoustic impedance during sound propagation, enabling noise generated by the gas at the combustion chamber to propagate through the combustion chamber into the gas passage and undergo reflection and interference at the narrowing or expanding section. This effectively reduces the probability of noise generated by the combustion chamber when the gas is injected at high speed through the micro-holes of the combustion chamber, as well as the probability of resonance noise generated by the combustion chamber vibration and resonance with other boiler components. Consequently, it reduces the noise generated by the heat exchanger during use and improves the user experience.

[0020] Additional aspects and advantages of this invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0021] The above and / or additional aspects and advantages of this utility model will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0022] Figure 1 This is a schematic diagram of the cover assembly according to an embodiment of the present utility model;

[0023] Figure 2 This is another schematic diagram of the cover assembly according to an embodiment of the present utility model;

[0024] Figure 3This is an exploded view of the cover assembly according to an embodiment of the present utility model;

[0025] Figure 4 This is a cross-sectional schematic diagram of the cover assembly according to an embodiment of the present utility model;

[0026] Figure 5 This is another cross-sectional schematic diagram of the cover assembly according to an embodiment of the present utility model;

[0027] Figure 6 This is another cross-sectional schematic diagram of the cover assembly according to an embodiment of the present utility model;

[0028] Figure 7 This is a schematic diagram of the cover body of the cover assembly according to an embodiment of the present utility model;

[0029] Figure 8 This is a schematic diagram of the sealing plate of the cover assembly according to an embodiment of the present utility model;

[0030] Figure 9 This is a schematic diagram of a heat exchanger according to an embodiment of the present invention;

[0031] Figure 10 This is another schematic diagram of a heat exchanger according to an embodiment of the present invention.

[0032] Figure label:

[0033] Cover 100, cover body 110, gas chamber 111, mounting part 112, sealing plate 120, first reinforcing rib 121, second reinforcing rib 122, second mounting hole 123, guide plate 130, combustion cylinder 140, ignition needle 150;

[0034] 200mm intake channel;

[0035] Gas passage 300, air inlet 310, air outlet 320, narrowing section 330;

[0036] The first narrowing structure 400, the first protrusion 410, the second protrusion 420, and the first mounting hole 421;

[0037] Shell 500, heat exchange chamber 510, heat exchange tube 520. Detailed Implementation

[0038] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this utility model, and should not be construed as limiting this utility model.

[0039] In the description of this utility model, it should be understood that the directional descriptions, such as up, down, front, back, left, right, etc., indicate the directional or positional relationship based on the directional or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model 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 utility model.

[0040] In the description of this utility model, "several" means one or more, "multiple" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. If "first" or "second" is used in the description, it is only for the purpose of distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0041] In the description of this utility model, unless otherwise explicitly defined, terms such as "setting," "installation," and "connection" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this utility model in conjunction with the specific content of the technical solution.

[0042] Reference Figures 1 to 6 An embodiment of this utility model provides a cover assembly, including a cover 100. The cover 100 is provided with an air inlet channel 200 and a gas channel 300. The two ends of the gas channel 300 are respectively provided with an air inlet 310 and an air outlet 320. The air inlet 310 is connected to the air inlet channel 200, and the air outlet 320 is used to connect to the combustion cylinder 140. The gas channel 300 has at least one narrowing section 330, and the cross-sectional area of ​​the narrowing section 330 is smaller than the cross-sectional area of ​​the gas channel 300.

[0043] In the cover assembly of this utility model embodiment, the gas can enter the gas passage 300 from the air inlet passage 200 and then flow to the gas outlet 320. The gas outlet 320 is used to connect with the combustion cylinder 140, so that the gas at the gas outlet 320 can flow into the combustion cylinder 140 for ignition and combustion. By providing at least one narrowing section 330 within the gas passage 300, since the cross-sectional area of ​​the narrowing section 330 is smaller than that of the gas passage 300, the cross-sectional area of ​​the gas passage 300 will abruptly decrease at the narrowing section 330. This can cause a change in acoustic impedance during sound propagation, resulting in sound wave reflection and interference. This ensures that the noise generated by the gas from the combustion chamber 140 can propagate through the combustion chamber 140 into the gas passage 300 and undergo reflection and interference at the narrowing section 330. This effectively reduces the probability of noise generated by the combustion chamber 140 when the gas is injected at high speed through the micro-holes of the combustion chamber 140, as well as the resonance noise generated by the vibration of the combustion chamber 140 and resonance with other boiler components. This effectively reduces the noise generated during the operation of the heat exchanger and improves the user experience.

[0044] It is understood that in some embodiments, in addition to providing at least one narrowing section 330 in the gas passage 300 to achieve noise reduction, at least one expansion section can also be provided in the gas passage 300. Since the cross-sectional area of ​​the expansion section is larger than that of the gas passage 300, that is, the cross-sectional area of ​​the gas passage 300 will suddenly increase at the expansion section, this structure can also cause a change in acoustic impedance during sound propagation, thereby generating sound wave reflection and interference phenomena. This ensures that the noise generated at the combustion cylinder 140 can propagate into the gas passage and undergo reflection and interference at the expansion section, thereby effectively reducing the noise generated during the use of the heat exchanger and improving the user experience.

[0045] It is understood that in some embodiments, in addition to providing at least one narrowing section 330 or at least one expanding section within the gas passage 300, at least one narrowing section 330 and at least one expanding section can also be provided simultaneously within the gas passage 300. The cross-sectional area of ​​the narrowing section 330 is smaller than that of the gas passage 300, and the cross-sectional area of ​​the expanding section is larger than that of the gas passage 300. This causes the cross-sectional area of ​​the gas passage 300 to decrease abruptly at the narrowing section 330 and increase abruptly at the expanding section. The noise frequencies that can pass through the passages with different cross-sectional areas will also be different. This can block and filter noise of different frequencies, increase the reflection and interference effect of the inner wall of the gas passage 300 on sound waves, and help improve the noise reduction effect.

[0046] Reference Figures 1 to 7In some embodiments, the air intake channel 200 is disposed on the cover 100 and extends outward relative to the cover 100, and the cross-sectional area of ​​the air intake 310 is smaller than the cross-sectional area of ​​the air intake channel 200.

[0047] By adopting the above structure, a sudden reduction in the cross-sectional area of ​​the gas flow channel can be formed at the air inlet 310, thereby causing noise to be reflected and interfered at the air inlet 310, which can effectively reduce noise.

[0048] Reference Figures 1 to 7 In some embodiments, the gas passage 300 has at least two narrowing sections 330, all of which are spaced apart.

[0049] By adopting the above structure, and by setting at least two narrowing sections 330, with each narrowing section 330 spaced apart, the cross-sectional area of ​​the gas passage 300 will suddenly decrease when the gas flows rapidly into the narrowing section 330, and will suddenly increase when the gas flows rapidly out of the narrowing section 330. This allows the cross-sectional area of ​​the gas passage 300 to undergo multiple abrupt changes, thereby enabling multiple reflections and interferences of noise. Furthermore, since the noise frequencies that can pass through the passages with different cross-sectional areas will also be different, it is possible to block and filter noise of different frequencies, increase the reflection and interference effect of the inner wall of the gas passage 300 on sound waves, and thus improve the noise reduction effect.

[0050] It is understood that the number of narrowing portions 330 is at least two, wherein the cross-sectional areas of any two narrowing portions 330 may be the same or different, and this utility model does not make a specific limitation in this regard.

[0051] Reference Figures 1 to 7 In some embodiments, the inner sidewall of the gas passage 300 is provided with a first narrowing structure 400 corresponding to at least one set of narrowing portions 330. The first narrowing structure 400 includes at least one first protrusion 410, which protrudes from the inner sidewall of the gas passage 300 and forms the sidewall of the narrowing portion 330.

[0052] In the above structure, by providing a first narrowing structure 400 on the inner wall of the gas passage 300, the first narrowing structure 400 includes at least one first protrusion 410, which protrudes from the inner wall of the gas passage 300. This causes a sudden reduction in the cross-sectional area of ​​the gas passage 300 at the location of the first protrusion 410, thus defining a narrowed section 330 with a reduced cross-sectional area within the gas passage 300. The first protrusion 410 forms the sidewall of the narrowed section 330. Noise generated at the combustion chamber 140 can propagate into the gas passage 300 and be reflected and interfered with at the first protrusion 410, thereby effectively reducing the noise generated at the combustion chamber 140. In this structure, the first protrusion 410 simplifies the structure of the narrowed section 330, making its processing easier and faster.

[0053] Understandably, the first protrusion 410 can also serve as a turbulence barrier, hindering the flow of gas and reducing its flow speed. This reduces the speed at which gas is injected from the combustion chamber 140, thereby helping to reduce the noise generated at the combustion chamber 140. At the same time, this structure, by hindering gas flow, can also prolong the flow time of gas within the gas passage 300, allowing the gas and air to mix fully within the gas passage 300. This results in more complete combustion of the gas in subsequent combustion processes, improving the combustion efficiency of the gas.

[0054] Reference Figures 1 to 7 In some embodiments, the first narrowing structure 400 includes two oppositely arranged first protrusions 410, which are respectively disposed on two opposite sidewalls of the gas passage 300, and the narrowing portion 330 is located between the corresponding two first protrusions 410.

[0055] By adopting the above structure, the narrowing portion 330 is confined between the two first protrusions 410, thereby effectively reducing the cross-sectional area of ​​the narrowing portion 330, and the sidewall of the first protrusion 410 can form a reflective surface that reflects noise, thereby improving the reflection and interference effect of noise and further reducing the noise generated by the heat exchanger during use.

[0056] It is understandable that the aforementioned first narrowing structure 400 includes two first protrusions 410, which are only for... Figures 1 to 7 As an example, the narrowing portion 330 may also include one, three, four or more first protrusions 410, and the present invention does not specifically limit this.

[0057] Reference Figures 1 to 7In some embodiments, a guide plate 130 is provided inside the cover 100, and the gas passage 300 is formed by the guide plate 130 and the inner peripheral wall of the cover 100 surrounding each other. In the first narrowing structure 400, one of the first protrusions 410 is provided on the guide plate 130, and the other first protrusion 410 is provided on the peripheral wall of the cover 100 and arranged opposite to the guide plate 130.

[0058] In the above structure, the baffle plate 130 can facilitate the formation of a gas passage 300 within the cover 100, and can facilitate the flow of gas from the inlet 310 of the gas passage 300 to the outlet 320.

[0059] Understandably, referring to Figures 1 to 7 The guide plate 130 is arranged in an arc shape, and the gas passage 300 is arranged around the circumference of the cover 100. The entire gas passage 300 is arranged around the outer periphery of the gas outlet 320, which can extend the flow path of the gas passage 300, so that the gas and air can be fully mixed in the gas passage 300, and the gas can be burned more completely in the subsequent combustion process, thereby improving the combustion efficiency of the gas.

[0060] Reference Figures 1 to 8 In some embodiments, the cover 100 includes a cover body 110 and a sealing plate 120. The cover body 110 is provided with a gas chamber 111 and an opening communicating with the gas chamber 111. The sealing plate 120 is installed on the cover body 110 and blocks the opening. The guide plate 130 is provided on the inner wall of the gas chamber 111 and abuts against the sealing plate 120. The gas passage 300 is formed by the cover body 110, the sealing plate 120 and the guide plate 130 surrounding and defining each other. The air inlet 310 and the air inlet passage 200 are both provided on the cover body 110. The air outlet 320 is provided on the sealing plate 120. The combustion cylinder 140 can be installed on the sealing plate 120 and communicate with the air outlet 320.

[0061] By adopting the above structure, the cover 100 is divided into the main body and the sealing plate 120, which facilitates the installation of the cover 100 and the setting of the gas passage 300. The guide plate 130 is set in the gas chamber 111 of the cover body 110, and the gas passage 300 can be defined by installing the sealing plate 120 at the opening of the cover body 110. The structure is simple and easy to process.

[0062] It is understandable that the baffle 130 is located on the inner wall of the gas chamber 111. Specifically, refer to... Figures 1 to 7 The guide plate 130 can be integrally formed with the cover body 110, which facilitates the processing and manufacturing of the cover body 100 and also improves the structural strength of the cover body 100.

[0063] Reference Figures 1 to 8In some embodiments, the inner wall of the gas passage 300 is provided with a second narrowing structure corresponding to at least one set of narrowing portions 330. The second narrowing structure includes at least one second protrusion 420. The second protrusion 420 protrudes from the inner wall of the gas chamber 111 and abuts against the sealing plate 120. The second protrusion 420 is spaced apart from the guide plate 130 and defines the narrowing portion 330. The second protrusion 420 has a first mounting hole 421 for mounting the ignition needle 150. The sealing plate 120 has a second mounting hole 123 corresponding to the first mounting hole 421. The ignition needle 150 can pass through the second mounting hole 123.

[0064] By adopting the above structure, the second protrusion 420 can serve as the mounting structure for the ignition needle 150, which can be sequentially inserted into the first mounting hole 421 and the second mounting hole 123. In addition, the second protrusion 420 can also be spaced apart from the guide plate 130 to define a narrowing portion 330, so that the cross-sectional area of ​​the gas passage 300 can be abruptly reduced at the second protrusion 420, thereby enabling multiple reflections and interferences of noise, which is beneficial to improving the noise reduction effect and further reducing the noise generated during the use of the heat exchanger.

[0065] Understandably, referring to Figures 1 to 8 In some embodiments, the second narrowing structure includes two second protrusions 420, which are arranged at intervals between adjacent second protrusions 420. The narrowing portion 330 can be disposed between adjacent second protrusions 420. This not only increases the number of narrowing portions 330 and improves the noise reduction effect, but also facilitates the separate installation of the two ignition needles 150.

[0066] It is understood that the number of second protrusions 420 in the second narrowing structure can be two, one, three, four or more, depending on the number of ignition needles 150 to be installed. This utility model does not make any specific limitation in this regard.

[0067] Reference Figures 1 to 8 In some embodiments, the sealing plate 120 is provided with at least one first reinforcing rib 121, the first reinforcing rib 121 protruding toward the gas passage 300, and at least one first reinforcing rib 121 is located within the narrowing portion 330.

[0068] By adopting the above structure, the arrangement of the first reinforcing rib 121 can not only improve the structural strength of the sealing plate 120, but also, since the first reinforcing rib 121 protrudes towards the gas passage 300 and at least one first reinforcing rib 121 is located within the narrowing portion 330, the first reinforcing rib 121 located within the narrowing portion 330 protruding towards the gas passage 300 can further reduce the cross-sectional area at the narrowing portion 330, thereby increasing the abrupt change in the cross-sectional area of ​​the gas passage 300 at the narrowing portion 330, which can enhance the interference and reflection of noise and improve the noise reduction effect.

[0069] Reference Figures 1 to 8 In some embodiments, a mounting portion 112 protrudes from the gas chamber 111 of the cover body 110, and the sealing plate 120 can abut against and be installed on the mounting portion 112, thereby facilitating the installation between the sealing plate 120 and the cover body 110. The sealing plate 120 and the mounting portion 112 can be connected by fasteners. Specifically, the mounting portion 112 has a first fastening hole (not shown in the figure) for installing fasteners, and the sealing plate 120 has a second fastening hole (not shown in the figure) for installing fasteners. During installation, the second fastener is sequentially installed into the second fastening hole and the first fastening hole. The fastener can be a screw, bolt, etc.

[0070] Understandably, referring to Figures 1 to 8 In some embodiments, in order to further improve the structural strength of the sealing plate 120, the sealing plate 120 is also provided with a second reinforcing rib 122 corresponding to the second fastening hole. The second fastening hole is opened at the second reinforcing rib 122, thereby improving the structure of the sealing plate 120 at the second fastening hole, making the connection between the sealing plate 120 and the mounting part 112 more secure and stable, which is conducive to improving the installation stability between the sealing plate 120 and the cover body 110.

[0071] Reference Figure 9 and Figure 10 An embodiment of the present invention also provides a heat exchanger, which is provided with a cover assembly of any of the above embodiments.

[0072] In the heat exchanger of this utility model embodiment, by adopting the cover assembly of any of the above embodiments, at least a narrowing portion 330 and / or at least an expanding portion are provided in the gas passage 300, so that the cross-sectional area of ​​the gas passage 300 can change abruptly. This can cause a change in acoustic impedance during sound propagation, so that the noise generated by the gas from the combustion cylinder 140 can be propagated through the combustion cylinder 140 into the gas passage 300 and reflect or interfere at the narrowing portion 330 or the expanding portion. This effectively reduces the probability of noise generated by the combustion cylinder 140 when the gas is injected at high speed from the micro-holes of the combustion cylinder 140, and the probability of resonance noise generated by the vibration of the combustion cylinder 140 and resonance with other parts of the boiler. Thus, the noise generated during the use of the heat exchanger can be effectively reduced, and the user experience can be improved.

[0073] Understandably, referring to Figure 9 and Figure 10 In some embodiments, the heat exchanger includes a housing 500, a heat exchange chamber 510, a heat exchange tube 520 installed in the heat exchange chamber 510, a cover 100 covering the housing 500, a combustion cylinder 140 installed on the cover 100 and located in the heat exchange chamber 510, and the combustion is achieved through multiple micro-holes for gas to flow out. In use, the gas enters the gas passage 300 through the inlet passage 200, then flows into the combustion cylinder 140 through the outlet 320, and finally flows out from the micro-holes of the combustion cylinder 140. The cover 100 is also equipped with an ignition needle 150, the ignition part of which is located on one side of the combustion cylinder 140, thereby igniting and burning the gas flowing out from the micro-holes of the combustion cylinder 140, thereby heating the heat exchange tube 520.

[0074] The embodiments of the present utility model have been described in detail above with reference to the accompanying drawings. However, the present utility model is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present utility model.

Claims

1. A cover assembly, characterized in that, include: The cover (100) is provided with an air intake channel (200) and a gas passage (300). The two ends of the gas passage (300) are respectively provided with an air inlet (310) and an air outlet (320). The air inlet (310) is connected to the air intake channel (200), and the air outlet (320) is used to connect to the combustion cylinder (140). The gas passage (300) has at least one narrowing section (330) with a cross-sectional area smaller than that of the gas passage (300), and / or the gas passage (300) has at least one expanding section with a cross-sectional area larger than that of the gas passage (300).

2. The cover assembly according to claim 1, characterized in that, The air intake channel (200) is provided on the cover (100) and extends outward relative to the cover (100), and the cross-sectional area of ​​the air inlet (310) is smaller than the cross-sectional area of ​​the air intake channel (200).

3. The cover assembly according to claim 1 or 2, characterized in that, The gas passage (300) has at least two narrow sections (330), and all the narrow sections (330) are arranged at intervals.

4. The cover assembly according to claim 3, characterized in that, The inner wall of the gas passage (300) is provided with a first narrowing structure (400) corresponding to at least one set of narrowing portions (330). The first narrowing structure (400) includes at least one first protrusion (410), which protrudes from the inner wall of the gas passage (300) and forms the side wall of the narrowing portion (330).

5. The cover assembly according to claim 4, characterized in that, The first narrowing structure (400) includes two oppositely arranged first protrusions (410), the two first protrusions (410) are respectively disposed on two opposite side walls of the gas passage (300), and the narrowing part (330) is located between the corresponding two first protrusions (410).

6. The cover assembly according to claim 5, characterized in that, The cover (100) is provided with a guide plate (130), and the gas passage (300) is formed by the guide plate (130) and the inner peripheral wall of the cover (100) surrounding each other. In the first narrowing structure (400), one of the first protrusions (410) is provided on the guide plate (130), and the other first protrusion (410) is provided on the peripheral wall of the cover (100) and arranged opposite to the guide plate (130).

7. The cover assembly according to claim 6, characterized in that, The cover (100) includes a cover body (110) and a sealing plate (120). The cover body (110) is provided with a gas chamber (111) and an opening communicating with the gas chamber (111). The sealing plate (120) is installed on the cover body (110) and blocks the opening. The guide plate (130) is disposed on the inner wall of the gas chamber (111) and abuts against the sealing plate (120). The gas passage (300) is formed by the cover body (110), the sealing plate (120) and the guide plate (130) surrounding and defining each other. The air inlet (310) and the air inlet passage (200) are both disposed on the cover body (110). The air outlet (320) is disposed on the sealing plate (120). The combustion cylinder (140) can be installed on the sealing plate (120) and communicates with the air outlet (320).

8. The cover assembly according to claim 7, characterized in that, The inner wall of the gas passage (300) is provided with a second narrowing structure corresponding to at least one set of narrowing portions (330). The second narrowing structure includes at least one second protrusion (420). The second protrusion (420) protrudes from the inner wall of the gas chamber (111) and abuts against the sealing plate (120). The second protrusion (420) is spaced apart from the guide plate (130) and defines the narrowing portion (330). The second protrusion (420) has a first mounting hole (421) for mounting an ignition needle (150), and the sealing plate (120) has a second mounting hole (123) corresponding to the first mounting hole (421), and the ignition needle (150) can pass through the second mounting hole (123).

9. The cover assembly according to claim 7, characterized in that, The sealing plate (120) is provided with at least one first reinforcing rib (121), the first reinforcing rib (121) protrudes toward the gas passage (300), and at least one first reinforcing rib (121) is located within the narrowing portion (330).

10. A heat exchanger, characterized in that, The cover assembly as described in any one of claims 1 to 9 is provided.

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