Thermal protection device for non-road diesel engine

Abstract

A thermal protection device for a non-road diesel engine belongs to the technical field of non-road diesel engines and comprises a first thermal protection device and a second thermal protection device, the first thermal protection device is applied to parts with compact surrounding space structures and small self surface areas, and the second thermal protection device is applied to parts without space limitation and with small self surface areas. And the heat dissipation area is large. The first thermal protection device comprises a heat preservation cotton layer and a stainless steel plate layer, the heat preservation cotton layer wraps the parts, and the stainless steel plate layer is arranged on the outer side of the heat preservation cotton layer. The utility model has the beneficial effects that the physical protection mode of the patch and the heat preservation cotton or the soft package heat insulation cotton is adopted, so that the heat transfer of high-temperature parts is reduced or blocked, the purposes of reducing heat loss and increasing the exhaust temperature are achieved, and the problems of short active regeneration period and frequent regeneration are solved.

Description

Technical Field

[0001] The utility model belongs to the technical field of non-road diesel engines, and in particular relates to a thermal protection device for non-road diesel engines. Background Art

[0002] With the implementation of the non-road China IV and non-road Euro V emission regulations, after-treatment systems are widely used in non-road diesel engines. There are two common technical routes: one is the EGR+DOC+DPF technical route, and the other is the DOC+DPF+SCR technical route. Both technical routes use DOC and DPF. At a certain temperature, DOC further oxidizes HC and CO in the exhaust into CO2 and H2O, and can also remove soluble organic components in the exhaust. The DPF is a wall-flow structure that can effectively capture particulate matter in the exhaust, reduce PM and PN, and meet regulatory requirements. When the particulate matter in the DPF increases to a certain mass, it will cause the exhaust back pressure to increase and the engine performance to decline. At this time, the DPF needs to be regenerated to remove the particulate matter.

[0003] The oxidation of HC and CO in the DOC and the removal of particulate matter in the DPF in the after-treatment need to be carried out at a certain temperature. Based on the existing diesel engine structure, the temperature requirements of the after-treatment cannot be met, which will lead to incomplete conversion of HC and CO, and the particulate matter in the DPF cannot be burned normally, resulting in frequent regeneration and short regeneration cycles. Increasing the exhaust temperature is a good way to solve the problems of short active regeneration cycles and frequent regeneration. However, during the normal operation of the engine body, a large amount of heat is lost from the supercharger, exhaust pipe and after-treatment front pipe, and a thermal protection device needs to be added to solve the problem of heat loss. Utility Model Content

[0004] In view of the shortcomings of the existing technology, the purpose of this utility model is to design a thermal protection device for non-road diesel engines to solve the problem mentioned in the background technology that during the normal operation of the engine body, a large amount of heat is lost from the supercharger, exhaust pipe, and after-treatment front pipe.

[0005] To achieve the above-mentioned objectives, the present invention adopts the following technical solution: a thermal protection device for a non-road diesel engine, comprising a first thermal protection device and a second thermal protection device. The first thermal protection device is applied to components with a compact surrounding space structure and a small surface area, and the second thermal protection device is applied to components with no spatial restrictions and a large heat dissipation area.

[0006] The first heat protection device includes a heat-insulating cotton layer and a stainless steel plate layer. The heat-insulating cotton layer is wrapped around the outside of the component, and the stainless steel plate layer is provided on the outside of the heat-insulating cotton layer.

[0007] The second thermal protection device includes a silicone cloth layer, a high-silica cloth layer A, a high-silica needle-punched felt layer, a high-silica cloth layer B and a stainless steel mesh layer. The inner side of the stainless steel mesh layer is in contact with the components, and a high-silica cloth layer B is provided on the outer side of the stainless steel mesh layer. A high-silica needle-punched felt layer is provided on the outer side of the high-silica cloth layer B. A high-silica needle-punched felt layer is provided on the outer side of the high-silica needle-punched felt layer. A silicone cloth layer is provided on the outer side of the high-silica cloth layer A.

[0008] The thermal insulation cotton layer adopts high silica fiber felt, which has flame retardancy of Class A, and has a thickness greater than 8mm and less than 10mm; the stainless steel plate layer adopts stainless steel corrugated plate with a thickness of 0.2mm, which is welded to the parts by spot welding.

[0009] The thickness of the second thermal protection device is greater than 10 mm and less than 12 mm. The stainless steel mesh layer, high-silica cloth layer B, high-silica needle-punched felt layer, high-silica cloth layer A and silicone cloth layer are wrapped around the outside of the component in sequence, and the outside of the silicone cloth layer is tightened and fixed with a spring hook.

[0010] The beneficial effect of the utility model is that by adopting the physical protection method of patch + thermal insulation cotton or soft-pack thermal insulation cotton, the heat transfer of high-temperature parts is reduced or blocked, thereby achieving the purpose of reducing heat loss and increasing exhaust temperature, thereby solving the problem of short active regeneration cycle and frequent regeneration. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 This is a schematic diagram of the position of the utility model on a non-road diesel engine.

[0012] Figure 2 This is a schematic structural diagram of the first thermal protection device of the present utility model.

[0013] Figure 3 This is a schematic structural diagram of the second thermal protection device of the present utility model.

[0014] In the figure: 1. First thermal protection device, 101. Insulation cotton layer, 102. Stainless steel plate layer, 2. Second thermal protection device, 201. Silicone cloth layer, 202. High-silica cloth layer A, 203. High-silica needle-punched felt layer, 204. High-silica cloth layer B, 205. Stainless steel mesh layer, 3. Exhaust pipe, 4. After-treatment front pipe. DETAILED DESCRIPTION

[0015] The following will be combined with the drawings of this specification to clearly and completely describe the technical solution of the utility model. It should be noted that the embodiments described are only some of the embodiments of the utility model, not all of them. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the utility model.

[0016] See also Figure 1-Figure 3 A thermal protection device for a non-road diesel engine includes a first thermal protection device 1 and a second thermal protection device 2. The first thermal protection device 1 is applied to components with a compact surrounding structure and a small surface area, typically used on high-temperature components such as exhaust pipes and superchargers. The second thermal protection device 2 is applied to components with no spatial restrictions and a large heat dissipation area, typically used on high-temperature components such as exhaust connecting pipes and after-treatment front pipes. The first thermal protection device 1 includes a thermal insulation layer 101 and a stainless steel plate layer 102. The thermal insulation layer 101 is wrapped around the exterior of the exhaust pipe 3, and the stainless steel plate layer 102 is disposed outside the thermal insulation layer 101. The second thermal protection device 2 comprises a silicone cloth layer 201, a high-silica cloth layer A 202, a high-silica needle-punched felt layer 203, a high-silica cloth layer B 204, and a stainless steel mesh layer 205. The inner side of the stainless steel mesh layer 205 contacts the post-processing front pipe 4. The high-silica cloth layer B 204 is located outside the stainless steel mesh layer 205. The high-silica needle-punched felt layer 203 is located outside the high-silica cloth layer B 204. The high-silica needle-punched felt layer 203 is located outside the high-silica cloth layer A 202. The silicone cloth layer 201 is located outside the high-silica cloth layer A 202. The thermal insulation layer 101 is made of high-silica fiber felt with Class A flame retardancy and a thickness greater than 8 mm and less than 10 mm. The stainless steel plate layer 102 is made of 0.2 mm thick corrugated stainless steel plate and is spot-welded to the exhaust pipe 3. The second thermal protection device 2 has a thickness greater than 10 mm and less than 12 mm, and is wrapped around the outside of the post-processing front pipe 4 from the inside out, and is fastened and fixed with a spring hook.

[0017] During use, the utility model:

[0018] In the case of the first thermal protection device 1: first, high-silica fiber felt is wrapped around the outside of the exhaust pipe 3 to form a thermal insulation layer 101. When the thickness of the thermal insulation layer 101 reaches between 8 mm and 10 mm, it is wrapped with a 0.2 mm stainless steel corrugated plate or a 0.15 mm stainless steel embossed plate. After wrapping, the joints are spot welded to complete the installation of the first thermal protection device 1.

[0019] In the case of the second thermal protection device 2: first, the outside of the post-processing front tube 4 is wrapped with a stainless steel mesh to form a stainless steel mesh layer 205, and then the outside of the stainless steel mesh layer 205 is conformally wrapped with high-silica cloth to form a high-silica cloth layer B204, and then the outside of the high-silica cloth layer B204 is conformally wrapped with high-silica needle felt to form a high-silica needle felt layer 203, and then the outside of the high-silica needle felt layer 203 is conformally wrapped with high-silica cloth to form a high-silica cloth layer A202, and finally the outside of the high-silica cloth layer A202 is conformally wrapped with silicone cloth to form a silicone cloth layer 201, completing the installation of the second thermal protection device 2;

[0020] It should be noted that the first thermal protection device 1 is aimed at components with compact surrounding space structure and small surface area, such as supercharger, exhaust pipe 3 and other high-temperature components. The overall assembly is simple and can also achieve the insulation effect. The disadvantage is that because it needs to be fixed by spot welding, there is no insulation cotton near the welding point, and the overall insulation effect is weaker than the second protection device 2; the second thermal protection device 2 is aimed at components with no space restrictions and large heat dissipation area, such as exhaust connecting pipe, after-treatment front pipe 4 and other high-temperature components. Compared with the first thermal protection device 1, the exhaust temperature of the second thermal protection device 2 is generally 20℃~30℃ higher due to differences in machine models and layout structures. Whether it is tightened and fixed with spring hooks or directly fixed with bolts, it is simple to operate and easy to assemble, and has a good effect on increasing the exhaust temperature.

[0021] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

[0022] The parts not described in detail in this utility model are prior art.

Claims

1. A thermal protection device for a non-road diesel engine, comprising a first thermal protection device (1) and a second thermal protection device (2), characterized in that: The first thermal protection device (1) is applied to components with a compact surrounding space structure and a small surface area, and the second thermal protection device (2) is applied to components with no spatial restrictions and a large heat dissipation area; The first heat protection device (1) comprises a heat-insulating cotton layer (101) and a stainless steel plate layer (102), wherein the heat-insulating cotton layer (101) is wrapped around the outside of the component, and the stainless steel plate layer (102) is provided on the outside of the heat-insulating cotton layer (101); The second thermal protection device (2) comprises a silicone cloth layer (201), a high-silica cloth layer A (202), a high-silica needle-punched felt layer (203), a high-silica cloth layer B (204) and a stainless steel mesh layer (205), wherein the inner side of the stainless steel mesh layer (205) contacts the component, a high-silica cloth layer B (204) is provided on the outer side of the stainless steel mesh layer (205), a high-silica needle-punched felt layer (203) is provided on the outer side of the high-silica cloth layer B (204), a high-silica cloth layer A (202) is provided on the outer side of the high-silica needle-punched felt layer (203), and a silicone cloth layer (201) is provided on the outer side of the high-silica cloth layer A (202).

2. A thermal protection device for a non-road diesel engine according to claim 1, characterized in that: The thermal insulation cotton layer (101) is made of high-silica fiber felt, which has a flame retardancy of Class A. The thickness of the thermal insulation cotton layer (101) is greater than 8 mm and less than 10 mm. The stainless steel plate layer (102) is made of a stainless steel corrugated plate with a thickness of 0.2 mm, which is welded to the components by spot welding.

3. The thermal protection device for a non-road diesel engine according to claim 1, characterized in that: The thickness of the second thermal protection device (2) is greater than 10 mm and less than 12 mm. The stainless steel mesh layer (205), high silica cloth layer B (204), high silica needle-punched felt layer (203), high silica cloth layer A (202) and silicone cloth layer (201) are sequentially wrapped around the outside of the component. The outside of the silicone cloth layer (201) is tightened and fixed by a spring hook.

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