A low flow resistance nozzle section device

Abstract

This invention provides a low-flow-resistance nozzle section device, comprising a nozzle section, multiple drag-reducing guide shrouds, and multiple nozzles. The nozzle section has a cylindrical structure and an inlet. The multiple drag-reducing guide shrouds are through-type cylindrical structures, with one end of each shroud conformally fitted and closed to the inlet to allow exhaust gas from the inlet to flow into the shroud. The other end of each shroud has a nozzle for gas to exit. The nozzle of each drag-reducing guide shroud is connected to the nozzle. This airflow structure design helps to solve the technical problem of the lack of a heat dissipation structure in the prior art.

Description

Technical fields:

[0001] This invention relates to the field of main engine exhaust system design in marine power systems, and in particular to a low flow resistance nozzle section device. Background technology:

[0002] Currently, in ship exhaust systems, exhaust ejectors are typically installed to draw in cooling air in order to reduce the heat load on the main engine enclosure. The amount of cooling air drawn in depends on both the ejector's performance and the downstream exhaust resistance. Improving the ejector's performance usually sacrifices some main engine output power. Therefore, it is necessary to increase the amount of cooling air drawn in by reducing the downstream exhaust resistance, thereby indirectly increasing the main engine's output power. Furthermore, to control exhaust temperature, infrared suppression devices are usually added to the exhaust system. These devices create a vacuum in the surrounding space by increasing the flow velocity of the main exhaust stream to draw in external cooling air. However, while increasing the airflow velocity in the exhaust pipe, this significantly increases exhaust resistance, thus reducing the main engine's output power.

[0003] This paper proposes a low-flow-resistance nozzle section device suitable for cooling high-flow-rate marine exhaust. This device utilizes the natural transition between the nozzle section inlet and the four nozzles, as well as the intermediate flow guide, to significantly reduce the angle between the pipe wall and the fluid velocity direction while avoiding abrupt changes in cross-section. This reduces the pressure loss of the exhaust system, thereby increasing the intake volume of cooling air for the exhaust ejector and enhancing the main engine's output power. Simultaneously, reducing the nozzle outlet diameter increases the airflow velocity after passing through the nozzle section, ensuring the nozzle's ability to eject cooling air.

[0004] Therefore, there is an urgent need for a low flow resistance nozzle section device, which would help solve the technical problem of the lack of a heat dissipation structure in the existing technology. Summary of the Invention:

[0005] In one embodiment, the present invention provides a low flow resistance nozzle section device, which, through air passage structure design, helps to solve the technical problem of the lack of a heat dissipation structure in the prior art.

[0006] The low flow resistance nozzle section device includes a nozzle section, multiple drag-reducing guide shields, and multiple nozzles;

[0007] The nozzle section has a cylindrical structure and has an inlet;

[0008] Multiple drag-reducing guide shrouds are through cylindrical structures. One end of each drag-reducing guide shroud is fitted and sealed to the inlet so that the exhaust gas from the inlet is poured into the drag-reducing guide shroud. The other end of each drag-reducing guide shroud has a nozzle so that the gas is discharged through the nozzle.

[0009] The nozzle of each of the drag-reducing guide shields is connected to the nozzle.

[0010] In one embodiment, the angle between the intersection of the inlet arc of the nozzle section and the projection of the arc at the other end of the drag-reducing guide shield is between 100° and 120°.

[0011] In one embodiment, the ratio of the radius of the arc at the other end of the drag-reducing guide shield to the radius of the inlet arc of the nozzle section is between 0.76 and 0.88.

[0012] In one embodiment, the diameter of the nozzle airflow outlet is greater than 90% of the inlet diameter.

[0013] In one embodiment, the included angle is 110°.

[0014] In one embodiment, the ratio of the radius of the arc at the other end of the drag-reducing guide shield to the radius of the inlet arc of the nozzle section is 0.82.

[0015] In one embodiment, there are four drag-reducing guide shields.

[0016] In one embodiment, the radius of the arc at the other end of the drag-reducing guide shield and the radius of the arc at the inlet of the nozzle section satisfy the following relationship:

[0017]

[0018] In one embodiment, the low flow resistance nozzle section device further includes an infrared suppression device;

[0019] The infrared suppression device is located at the airflow outlet of the nozzle.

[0020] In one embodiment, the low flow resistance nozzle section device is used to reduce the thermal load on the main unit housing. Attached image description:

[0021] Figure 1 This is a schematic diagram of the structure of a low flow resistance nozzle section device in one embodiment of the present invention;

[0022] Figure 2 A schematic diagram of a low flow resistance nozzle section device in another embodiment of the present invention;

[0023] Figure 3 This is a schematic diagram of the guide cone of the low flow resistance nozzle section device in another embodiment of the present invention;

[0024] Figure 4 This is a schematic diagram of a tapered nozzle in another embodiment of the low flow resistance nozzle section device of the present invention.

[0025] Figure 5 This is a schematic diagram of the flow path of the airflow through the low flow resistance nozzle section in another embodiment of the present invention.

[0026] Figure label:

[0027] Nozzle Section 1

[0028] Imported 11

[0029] Drag Reduction Shield 2

[0030] Nozzle 21

[0031] Nozzle 3 Detailed implementation method:

[0032] 1. In the exhaust system of marine main engines, how to reduce the pressure loss of the exhaust system, thereby increasing the airflow rate in the exhaust ejector device, increasing the intake of cooling air, and increasing the output power of the main engine.

[0033] 2. How to ensure the ejection performance of the infrared suppressor while reducing exhaust resistance.

[0034] Figure 1 This is a schematic diagram of the structure of a low flow resistance nozzle section device in one embodiment of the present invention; Figure 2 A schematic diagram of a low flow resistance nozzle section device in another embodiment of the present invention; Figure 3 This is a schematic diagram of the guide cone of the low flow resistance nozzle section device in another embodiment of the present invention; Figure 4 This is a schematic diagram of a tapered nozzle in another embodiment of the low flow resistance nozzle section device of the present invention. Figure 5 This is a schematic diagram of the flow path of the airflow through the low flow resistance nozzle section in another embodiment of the present invention.

[0035] like Figures 1 to 5 As shown, in one embodiment, the present invention provides a low flow resistance nozzle section device, the low flow resistance nozzle section device including nozzle section 1, multiple drag-reducing guide shrouds 2, and multiple nozzles 3;

[0036] The nozzle section 1 has a cylindrical structure and has an inlet 11;

[0037] Multiple drag-reducing guide shrouds 2 are through cylindrical structures. One end of the multiple drag-reducing guide shrouds 2 is fitted and closed to the inlet 11 so that the exhaust gas from the inlet 11 is poured into the drag-reducing guide shrouds 2. The other end of the drag-reducing guide shrouds 2 has a nozzle 21 so that the gas is discharged through the nozzle 21.

[0038] Each drag-reducing guide shroud 2 has a nozzle 21 connected to a nozzle 3.

[0039] This embodiment provides a specific structure for a low-flow-resistance nozzle section device. Through the natural transition between the nozzle section inlet and the four nozzles, and the intermediate guide cone, the angle between the pipe wall and the fluid velocity direction is significantly reduced, lowering the pressure loss of the exhaust system, increasing the intake of cooling air for the exhaust ejector device, and simultaneously enhancing the main unit's output power. Reducing the nozzle outlet diameter further converts pressure energy into kinetic energy after the airflow enters the nozzle, increasing the airflow velocity after passing through the nozzle section and ensuring the nozzle's ability to eject cooling air.

[0040] The inlet of nozzle section 1 is connected to the exhaust system pipeline in the exhaust system, and its diameter is consistent with the diameter of the upstream exhaust system pipeline; the drag-reducing guide shroud 2 is located between the inlet of nozzle section 1 and nozzle 3, and is laid out by the arcs at both ends of the inlet end face of a single nozzle 3 and the inlet end face of nozzle section 1.

[0041] In one embodiment, the angle between the intersection of the inlet arc of nozzle section 11 and the arc projection of the other end of drag-reducing shield 2 is between 100° and 120°.

[0042] This embodiment provides a specific implementation where the angle between the intersection point of the inlet arc 11 of the nozzle section 1 and the arc projection of the other end of the drag-reducing guide shroud 2 is between 100° and 120°. Specifically, arc 1 coincides with the inlet wall of the nozzle section, and the other end arc 2 connects to arc 1.

[0043] In one embodiment, the ratio of the radius of the arc at the other end of the drag-reducing guide shroud 2 to the radius of the arc at the inlet 11 of the nozzle section 1 is between 0.76 and 0.88.

[0044] In this embodiment, a specific implementation is provided in which the ratio of the radius of the arc at the other end of the drag-reducing guide shield 2 to the radius of the arc at the inlet 11 of the nozzle section 1 is between 0.76 and 0.88.

[0045] In one embodiment, the diameter of the airflow outlet of the nozzle 3 is greater than 90% of the inlet diameter.

[0046] In this embodiment, a preferred value is provided where the diameter of the airflow outlet of the nozzle 3 is greater than 90% of the inlet diameter.

[0047] In one embodiment, the included angle is 110°.

[0048] This embodiment provides a preferred angle for the included angle.

[0049] In one embodiment, the ratio of the radius of the arc at the other end of the drag-reducing guide shroud 2 to the radius of the arc at the inlet 11 of the nozzle section 1 is 0.82.

[0050] In this embodiment, a preferred radius ratio of 0.82 is provided.

[0051] In one embodiment, there are four drag-reducing guide shields 2.

[0052] In this embodiment, a preferred quantity of four drag-reducing guide shields is provided. The geometric wall shape formed by the intersection of four individually laid-out frustums constitutes the drag-reducing guide shield. This method reduces the angle between the pipe wall and the airflow velocity direction, thereby reducing exhaust resistance loss. The guide cone is the geometric wall formed in the middle after the intersection of four individually laid-out frustums. Based on the intersection line, the geometric wall surface outside the cone is removed to form... Figure 4 The geometry shown is as follows. The guide cone avoids abrupt changes in the cross-section of the nozzle section, allowing the airflow area to gradually decrease as it passes through the nozzle section. This reduces the overall angle between the airflow and the wall, thereby reducing exhaust resistance losses as the airflow passes through the nozzle section. To ensure the infrared suppressor's ejection performance, the nozzle exit diameter is reduced, and the exit diameter should not be less than 90% of the inlet diameter. This further increases the airflow velocity after it enters the nozzle and passes through the nozzle section. Although this structure increases exhaust resistance, it is far less than the resistance reduction achieved by the airflow reduction device, ensuring the nozzle's ability to eject cooling air.

[0053] In one embodiment, the radius of the arc at the other end of the drag-reducing guide shield 2 and the radius of the arc at the inlet 11 of the nozzle section 1 satisfy the following relationship:

[0054]

[0055] This embodiment provides a specific data range.

[0056] In one embodiment, the low flow resistance nozzle section device is used to reduce the thermal load on the main unit housing.

[0057] This embodiment provides an application scenario for the low flow resistance nozzle section device.

[0058] The embodiments are merely illustrative of the implementation of the present invention, but the invention itself is not limited to the embodiments and the accompanying drawings.

[0059] The beneficial effects of this invention are as follows:

[0060] Compared with traditional structural solutions, this invention significantly reduces the pressure loss in the nozzle section of the exhaust system. Under the same conditions, it allows the exhaust ejector to draw in more cooling air, while increasing the main unit's output power and ensuring the ejection performance of the infrared suppressor.

[0061] Based on the above structure:

[0062] This is a low-flow-resistance nozzle section device suitable for cooling high-flow-rate marine exhaust. The device includes a drag-reducing shroud, a guide cone, and nozzles. The lower end face of the drag-reducing shroud connects to the nozzle section inlet, and the upper end face connects to four nozzles. A single connection path is shown below. Figure 2 As shown, the upper end face of the connecting section is the nozzle inlet, and the lower end face consists of two arc segments. Arc 1 coincides with the nozzle inlet end face, with an included angle α of 110°. The radius of arc 2 should be smaller than the radius of the previous arc segment, and the ratio of its radius to the nozzle inlet wall radius is between 0.76 and 0.88, with a ratio of 0.82 here. The four columnar connecting sections intersect to form a drag-reducing guide shield and a guide cone, as shown. Figure 3 As shown. It is important to note that the length and guiding angle of the guide cone are closely related to the small-radius arc mentioned above. When the airflow passes through this device, it will flow into the four nozzles under the action of the guide cone. Simultaneously, the drag-reducing guide shield significantly reduces the angle between the device and the airflow velocity direction, thereby reducing flow energy loss, as shown. Figure 5 As shown. Because this device reduces exhaust resistance, the power supplied by the main unit for exhaust is also reduced, resulting in a decrease in the airflow velocity from the nozzle, thus affecting the ejection performance of the infrared suppressor. Therefore, the nozzle exit diameter is reduced (the actual size needs to be determined based on operating conditions, but should not be less than 90% of the inlet diameter), such as... Figure 4 As shown, the power loss of the main unit is used to increase the airflow velocity from the nozzle, but this power loss is far less than the power saved by the drag-reducing shield. Therefore, for the entire device, the energy loss in the exhaust system piping is still reduced, while the infrared suppressor's ejection performance is satisfied.

[0063] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles and processes of the present invention. Various changes and modifications can be made to the present invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as defined by the appended claims and their equivalents.

Claims

1. A low flow resistance nozzle section device, characterized in that, The low flow resistance nozzle section device includes: A nozzle section (1) is a cylindrical structure, and the nozzle section has an inlet (11). Multiple drag-reducing guide hoods (2) are through cylindrical structures. The geometric wall shape formed by the intersection of multiple individually laid-out frustums on the periphery is the drag-reducing guide hood. One end of the multiple drag-reducing guide hoods (2) is fitted and closed to the inlet (11) so that the exhaust gas of the inlet (11) is poured into the drag-reducing guide hood (2). The other end of the drag-reducing guide hood (2) has a nozzle (21) so that the gas is discharged through the nozzle (21). A flow guide cone is a geometric wall formed in the middle by the intersection of four separately laid-out frustums, with the intersection line as the reference, and the geometric wall outside the cone removed. Multiple nozzles (3), with the nozzle (21) of each of the drag-reducing guides (2) connected to the nozzle (3); The angle between the intersection of the arc of the inlet (11) of the nozzle section (1) and the arc projection of the other end of the drag-reducing guide (2) is between 100° and 120°. The ratio of the radius of the arc at the other end of the drag-reducing guide shield (2) to the radius of the arc at the inlet (11) of the nozzle section (1) is between 0.76 and 0.

88.

2. The low flow resistance nozzle section device according to claim 1, characterized in that, The diameter of the airflow outlet of the nozzle (3) is greater than 90% of the inlet diameter.

3. The low flow resistance nozzle section device according to claim 2, characterized in that, The included angle is 110°.

4. The low flow resistance nozzle section device according to claim 3, characterized in that, The ratio of the radius of the arc at the other end of the drag-reducing guide shield (2) to the radius of the arc at the inlet (11) of the nozzle section (1) is 0.

82.

5. The low flow resistance nozzle section device according to claim 4, characterized in that, There are four drag-reducing guide shields (2).

6. The low flow resistance nozzle section device according to claim 5, characterized in that, The arc at the other end of the drag-reducing guide shield (2) and the arc radius of the inlet (11) of the nozzle section (1) satisfy the following relationship: 。 7. The low flow resistance nozzle section device according to claim 6, characterized in that, The low flow resistance nozzle section device is used to reduce the thermal load on the main unit housing.

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