Exhaust pipe heat insulation structure

Abstract

The application discloses an exhaust pipe heat preservation and insulation structure, relates to the technical field of engine exhaust, and comprises an exhaust jacket, one end of which is connected with an engine turbocharger outlet, and the other end is fixedly installed with an exhaust pipe one; an exhaust pipe joint, one end of which is connected with a tail gas aftertreatment inlet, and the other end is fixedly installed with an exhaust pipe two; and a corrugated pipe, both ends of which are connected with the exhaust pipe one and the exhaust pipe two respectively, so that the exhaust jacket, the exhaust pipe one, the corrugated pipe, the exhaust pipe two and the exhaust pipe joint constitute a tail gas passage; a soft wrapping layer is sleeved outside the corrugated pipe, and hard wrapping layers are sleeved outside the exhaust jacket, the exhaust pipe one, the exhaust pipe two and the exhaust pipe joint. The hard wrapping layer and the soft wrapping layer are arranged, the wrapping layer material combination is optimized, heat exchange between the exhaust pipe and the outside world is reduced, temperature loss is reduced, the whole temperature drop of the exhaust pipe is effectively controlled, and the tail gas temperature meets the temperature required by purification.

Description

Technical Field

[0001] This utility model relates to the field of engine exhaust structure technology, specifically an exhaust pipe heat insulation structure. Background Technology

[0002] Currently, non-road engineering vehicles sold to China, Europe, and North America are required to meet China IV, Euro V, and US IV emission standards, respectively. The main method for controlling exhaust pollutants from non-road engineering vehicles is to use urea for after-treatment, further oxidizing unburned harmful gases (NOx, COw, HC) in the exhaust to purify it. The initial catalytic activity temperature of oxidation catalysts is generally 150-160℃, with an optimal reaction temperature range of 250-450℃.

[0003] To meet vehicle emission regulations, the temperature drop of the exhaust pipe from the turbocharger outlet to the aftertreatment inlet is controlled as follows: for China IV emission standard vehicles, the exhaust pipe temperature drop is less than 25°C; for Euro V vehicles, it is less than 20°C; and for US IV vehicles, it is less than 14°C. With the continuous upgrading of emission regulations (such as the implementation of China V and China VI emission standards), even more stringent technical requirements will be placed on the exhaust pipe temperature drop. This utility model aims to provide a composite thermal insulation structure on the outer surface of the exhaust pipe to reduce temperature loss caused by heat exchange between the exhaust pipe and the outside environment, thereby effectively controlling the temperature drop throughout the exhaust pipe. Utility Model Content

[0004] The purpose of this utility model is to provide a thermal insulation structure for exhaust pipes to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, this utility model provides the following technical solution: a thermal insulation structure for an exhaust pipe, comprising: The exhaust sleeve has one end connected to the outlet of the engine turbocharger and the other end fixedly installed with an exhaust pipe. The exhaust pipe connector has one end connected to the exhaust aftertreatment inlet and the other end fixedly installed with exhaust pipe two. The bellows is connected at both ends to exhaust pipe one and exhaust pipe two respectively, so that the exhaust sleeve, exhaust pipe one, bellows, exhaust pipe two and exhaust pipe joint form the exhaust gas passage. The corrugated pipe is covered with a soft outer layer, while the exhaust sleeve, exhaust pipe one, exhaust pipe two, and exhaust pipe connector are all covered with a hard outer layer.

[0006] Preferably, the rigid wrapping layer adopts a multi-layer composite structure, including a first high-silica cotton layer, a first glass fiber cloth layer, and a 304 stainless steel embossed plate layer; wherein, the first high-silica cotton layer is located at the innermost layer, the first glass fiber cloth layer is tightly wrapped around the outside of the first high-silica cotton layer, and the 304 stainless steel embossed plate layer is wrapped around the outside of the first glass fiber cloth layer by welding process.

[0007] Preferably, the thicknesses of each layer of the rigid coating are as follows: 16mm for the first high-silica cotton layer, 0.2mm for the first glass fiber cloth layer, and 0.15mm for the 304 stainless steel embossed plate layer.

[0008] Preferably, a safe distance of 40mm must be maintained between the rigid wrapping layer and the external port of the exhaust sleeve and the external port of the exhaust pipe connector.

[0009] Preferably, the soft wrapping layer adopts a multi-layer composite structure, consisting of a silicone cloth layer, a second high-silica cotton layer, a second glass fiber cloth layer and a fixing spring hook. The second glass fiber cloth layer is attached to the outer wall of the exhaust pipe, the second high-silica cotton layer is tightly attached to and wrapped around the outside of the second glass fiber cloth layer, and the silicone cloth layer is positioned on the outside of the second high-silica cotton layer.

[0010] Preferably, the silicone cloth layer, the second high-silica cotton layer, and the second glass fiber cloth layer are connected as one piece by a sewing process.

[0011] Preferably, the soft wrapping layer is a rectangular structural component, with its two ends forming a cylindrical body, and the two ends of the cylindrical body are fixed by setting a fixing spring hook.

[0012] Preferably: the silicone cloth layer is 0.42mm thick, the second high-silica cotton layer is 10mm thick, and the second glass fiber cloth layer is 0.2mm thick.

[0013] Compared with the prior art, the beneficial effects of this utility model are: This application reduces temperature loss caused by heat exchange between the exhaust pipe and the outside world by setting a hard coating layer and a soft coating layer and optimizing the combination of coating layer materials, thereby effectively controlling the temperature drop of the exhaust pipe throughout the process and making the exhaust gas temperature meet the temperature required for purification.

[0014] This application addresses the issue of using a soft outer layer over a corrugated pipe and a hard outer layer over exhaust pipes one and two. Considering the crucial role of the corrugated pipe in absorbing vibration and compensating for displacement in the exhaust system, it must maintain a certain degree of elasticity. Therefore, a hard outer layer cannot be used to wrap the corrugated pipe. To address this, a soft outer layer was specifically designed and manufactured based on the actual dimensions of the corrugated pipe, directly wrapping it around the outside of the pipe to achieve effective thermal insulation. The soft outer layer is also suitable for parts of the exhaust system that require periodic disassembly and inspection, making installation and removal convenient. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the exhaust pipe assembly of this utility model; Figure 2 This is a schematic diagram of the thermal insulation wrapping of the exhaust pipe of this utility model; Figure 3 This is a schematic diagram of the rigid encapsulation layer structure of this utility model; Figure 4 This is a schematic diagram of the soft coating layer structure of this utility model.

[0016] In the picture: 1. Exhaust sleeve; 2. Exhaust pipe one; 3. Corrugated pipe; 4. Exhaust pipe two; 5. Exhaust pipe connector; 6. Rigid wrapping layer; 61. First high-silica cotton layer; 62. First fiberglass cloth layer; 63. 304 stainless steel embossed plate layer; 7. Soft wrapping layer; 71. Silicone cloth layer; 72. Second high-silicone cotton layer; 73. Second glass fiber cloth layer; 74. Fixing spring hook. Detailed Implementation

[0017] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0018] In the description of the embodiments of this utility model, it should be noted that the terms "inner", "outer", "upper", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship in which the utility model product is usually placed when in use. 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.

[0019] Please see Figure 1-4 In this embodiment of the utility model, a thermal insulation structure for an exhaust pipe includes: Exhaust sleeve 1, one end is connected to the outlet of the engine turbocharger, and the other end is fixedly installed with exhaust pipe 2; Exhaust pipe connector 5, one end is connected to the exhaust gas aftertreatment inlet, and the other end is fixedly installed with exhaust pipe 2 4; The bellows 3 is connected at both ends to the exhaust pipe 2 and the exhaust pipe 4 respectively, so that the exhaust sleeve 1, the exhaust pipe 2, the bellows 3, the exhaust pipe 4, and the exhaust pipe connector 5 form the exhaust gas passage. The corrugated pipe 3 is covered with a soft wrapping layer 7, and the exhaust sleeve 1, exhaust pipe one 2, exhaust pipe two 4, and exhaust pipe connector 5 are all covered with a hard wrapping layer 6.

[0020] like Figure 3 As shown, the rigid wrapping layer 6 adopts a multi-layer composite structure, including a first high-silica cotton layer 61, a first glass fiber cloth layer 62, and a 304 stainless steel embossed plate layer 63; wherein, the first high-silica cotton layer 61 is located in the innermost position, the first glass fiber cloth layer 62 is tightly wrapped around the outside of the first high-silica cotton layer 61, and the 304 stainless steel embossed plate layer 63 is wrapped around the first glass fiber cloth layer 62 by welding process.

[0021] The thicknesses of each layer of the rigid coating layer 6 are as follows: the first high-silica cotton layer 61 is 16mm, the first glass fiber cloth layer 62 is 0.2mm, and the 304 stainless steel embossed plate layer 63 is 0.15mm.

[0022] Specifically, the rigid wrapping layer 6 adopts a multi-layer composite design, including a first high-silica cotton layer 61, a first fiberglass cloth layer 62, and a 304 stainless steel embossed plate layer 63. The first high-silica cotton layer 61, located at the innermost layer, possesses excellent thermal insulation performance and maintains stable structural performance even at high temperatures, providing reliable thermal insulation for the exhaust pipe. The first fiberglass cloth layer 62 has the same composition as the first high-silica cotton layer 61 but is made of fabric, tightly wrapping around the outside of the first high-silica cotton layer 61 to ensure that the first high-silica cotton layer 61 is evenly and neatly wrapped on the surface of the exhaust pipe, further optimizing the thermal insulation effect. The 304 stainless steel embossed plate layer 63, as the outermost layer of the rigid wrapping layer 6, is firmly wrapped around the exhaust pipe through a welding process. This layer has good wear resistance and pressure resistance, and can effectively resist oil stains, providing protection for the inner first high-silica cotton layer 61 and first fiberglass cloth layer 62, thereby extending the service life of the entire rigid wrapping layer 6. The rigid wrapping layer 6 has excellent thermal insulation performance and reliable sealing performance. The first high silica cotton layer 61 is a key part of thermal insulation. Its thickness can be adjusted according to the specific requirements of exhaust temperature drop under different application scenarios. While effectively meeting the thermal insulation requirements of exhaust pipe, it can also effectively control the manufacturing cost of exhaust pipe.

[0023] A safe distance of 40mm must be maintained between the rigid wrapping layer 6 and the external port of the exhaust sleeve 1 and the external port of the exhaust pipe connector 5.

[0024] Specifically, a hard coating layer 6 is wrapped around the outside of exhaust pipe 1 2 and exhaust pipe 2 4. To ensure that the hard coating layer 6 will not interfere with the connection between the exhaust pipe and the engine and aftertreatment, a safe distance of 40mm must be maintained between the hard coating layer 6 and the exhaust sleeve 1 and the exhaust pipe connector 5.

[0025] like Figure 4 As shown, the soft wrapping layer 7 adopts a multi-layer composite structure, consisting of a silicone cloth layer 71, a second high-silica cotton layer 72, a second glass fiber cloth layer 73, and a fixing spring hook 74. The second glass fiber cloth layer 73 is attached to the outer wall of the exhaust pipe, the second high-silica cotton layer 72 is tightly wrapped around the outside of the second glass fiber cloth layer 73, and the silicone cloth layer 71 is positioned outside the second high-silica cotton layer 72.

[0026] The silicone cloth layer 71, the second high-silica cotton layer 72, and the second glass fiber cloth layer 73 are connected as one piece by a sewing process.

[0027] The soft wrapping layer 7 is a rectangular structural component, with its two ends forming a cylindrical body, and the two ends of the cylindrical body are fixed by a fixing spring hook 74.

[0028] The thicknesses of each layer of the soft wrapping layer 7 are as follows: silicone cloth layer 71 is 0.42 mm, second high-silica cotton layer 72 is 10 mm, and second glass fiber cloth layer 73 is 0.2 mm.

[0029] Specifically, the rigid coating layer 6 is fixed to the surface of the exhaust pipe using a welding process, making disassembly inconvenient and suitable only for parts of the exhaust pipe that do not require regular disassembly and inspection. For example... Figure 4 As shown, the soft wrapping layer 7 also adopts a multi-layer composite structure, consisting of a silicone cloth layer 71, a second high-silica cotton layer 72, a second fiberglass cloth layer 73, and a fixing spring hook 74. The silicone cloth layer 71, the second high-silica cotton layer 72, and the second fiberglass cloth layer 73 are connected as one piece through a sewing process. The silicone cloth layer 71 has excellent waterproof, oil-proof, and windproof properties, effectively preventing heat loss from the exhaust pipe due to airflow. When wrapping, the silicone cloth layer 71 is on the outer side, and the second fiberglass cloth layer 73 adheres to the outer wall of the exhaust pipe. The entire soft wrapping layer 7 is wrapped around the exhaust pipe by the fixing spring hook 74. The fixing spring hook 74 has a certain tightening, adjustment, and cushioning function, ensuring that the soft wrapping layer is firmly wrapped on the surface of the exhaust pipe, and the installation and disassembly operations are extremely simple and quick. The soft wrapping layer 7 is convenient to install and disassemble, has good flexibility, and can be customized according to the actual shape and size of the exhaust pipe. In the exhaust pipeline, parts such as joints and bellows 3 that are not suitable for wrapping with a hard wrapping layer 6 due to their special structure can be wrapped with a soft wrapping layer 7.

[0030] Considering that the bellows 3 plays a crucial role in absorbing vibration and compensating for displacement in the exhaust pipe, it must maintain a certain degree of elasticity. Therefore, the rigid wrapping layer 6 cannot wrap the bellows 3. To address this, a soft wrapping layer 7 was specifically designed and manufactured based on the actual dimensions of the bellows 3, directly wrapping it around the outside of the bellows 3 to achieve effective thermal insulation. After operating the exhaust pipe according to the above wrapping scheme, the internal airflow temperature at both ends of the exhaust pipe was accurately measured. The measurement results showed that the airflow temperature at the turbocharger outlet was 395.7℃, while the airflow temperature at the aftertreatment inlet was 382.2℃, with a temperature difference of 13.5℃. This temperature difference is less than the 14℃ temperature drop requirement for exhaust pipes stipulated by the US IV emission standard, fully demonstrating that this thermal insulation structure can effectively meet the temperature drop control requirements of the exhaust pipe under the US IV emission standard.

[0031] Although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

[0032] Therefore, the above description is only a preferred embodiment of this application and is not intended to limit the scope of this application; that is, all equivalent modifications made in accordance with the scope of the claims of this application shall be within the protection scope of the claims of this application.

Claims

1. A thermal insulation structure for an exhaust pipe, characterized in that, include: The exhaust sleeve (1) is connected to the engine turbocharger outlet at one end and the exhaust pipe (2) is fixedly installed at the other end. The exhaust pipe connector (5) is connected to the exhaust gas aftertreatment inlet at one end and the exhaust pipe two (4) is fixedly installed at the other end. The bellows (3) is connected at both ends to exhaust pipe one (2) and exhaust pipe two (4) respectively, so that the exhaust sleeve (1), exhaust pipe one (2), bellows (3), exhaust pipe two (4) and exhaust pipe connector (5) form the exhaust gas passage; The corrugated pipe (3) is covered with a soft wrapping layer (7), and the exhaust sleeve (1), exhaust pipe one (2), exhaust pipe two (4), and exhaust pipe connector (5) are all covered with a hard wrapping layer (6).

2. The thermal insulation structure for the exhaust pipe according to claim 1, characterized in that: The rigid wrapping layer (6) adopts a multi-layer composite structure, including a first high silica cotton layer (61), a first glass fiber cloth layer (62), and a 304 stainless steel embossed plate layer (63); wherein, the first high silica cotton layer (61) is located in the innermost position, the first glass fiber cloth layer (62) is tightly wrapped around the outside of the first high silica cotton layer (61), and the 304 stainless steel embossed plate layer (63) is wrapped around the outside of the first glass fiber cloth layer (62) by welding process.

3. The thermal insulation structure for the exhaust pipe according to claim 2, characterized in that: The thicknesses of each layer of the rigid wrapping layer (6) are as follows: the first high silica cotton layer (61) is 16 mm, the first glass fiber cloth layer (62) is 0.2 mm, and the 304 stainless steel embossed plate layer (63) is 0.15 mm.

4. The exhaust pipe thermal insulation structure according to any one of claims 1-3, characterized in that: The hard wrapping layer (6) must maintain a safe distance of 40mm from the external port of the exhaust sleeve (1) and the external port of the exhaust pipe connector (5).

5. The exhaust pipe thermal insulation structure according to claim 1, characterized in that: The soft wrapping layer (7) adopts a multi-layer composite structure, consisting of a silicone cloth layer (71), a second high-silica cotton layer (72), a second glass fiber cloth layer (73), and a fixing spring hook (74). The second glass fiber cloth layer (73) is attached to the outer wall of the exhaust pipe, the second high-silica cotton layer (72) is tightly attached to and wrapped around the outside of the second glass fiber cloth layer (73), and the silicone cloth layer (71) is located on the outside of the second high-silica cotton layer (72).

6. The exhaust pipe thermal insulation structure according to claim 5, characterized in that: The silicone cloth layer (71), the second high-silica cotton layer (72), and the second glass fiber cloth layer (73) are connected together by a sewing process.

7. The exhaust pipe thermal insulation structure according to claim 5, characterized in that: The soft wrapping layer (7) is a rectangular structural component, with its two ends forming a cylindrical body, and the two ends of the cylindrical body are fixed by setting a fixing spring hook (74).

8. The thermal insulation structure for the exhaust pipe according to claim 5, characterized in that: The thicknesses of each layer of the soft wrapping layer (7) are as follows: silicone cloth layer (71) 0.42 mm, second high silica cotton layer (72) 10 mm, and second glass fiber cloth layer (73) 0.2 mm.

Images