High-speed train equipment cabin independent air duct

Abstract

This invention discloses an independent air duct for the equipment compartment of a high-speed train, relating to the field of ventilation and heat dissipation technology for rail vehicles. It can improve the cooling efficiency of the equipment compartment without altering its original structure and equipment layout, thus ensuring the normal operation of the equipment within the compartment. The independent air duct includes two contraction sections and one stabilization section. The contraction sections are symmetrically arranged at both ends of the stabilization section. One contraction section has an air inlet, and the other contraction section has an air outlet. The independent air duct is installed inside the equipment compartment, and the heat dissipation units for the heat-generating equipment within the equipment compartment are located within the stabilization section.

Description

Technical Field

[0001] This invention relates to the field of ventilation and heat dissipation technology for rail vehicles, and in particular to an independent air duct for the equipment compartment of a high-speed train. Background Technology

[0002] High-power electrical equipment such as converters located in the equipment compartment of high-speed trains generate a large amount of heat during operation. Currently, the cooling method used is forced air cooling with fans. Airflow enters and exits through ventilation openings on both sides of the equipment compartment, dissipating heat from the equipment through rapid airflow. As train speeds increase, the heat generated by each piece of equipment also increases, demanding higher cooling efficiency, rendering traditional cooling methods increasingly inadequate. Furthermore, aerodynamic effects significantly impact cooling and ventilation in the equipment compartment during high-speed train operation. Specifically, cooling and ventilation are suppressed near the rear of the train and enhanced near the front, leading to even more insufficient cooling efficiency in the equipment compartments of the rear cars. Insufficient cooling not only affects the normal operation of the equipment but, in severe cases, can also cause equipment malfunctions due to overheating, resulting in safety accidents.

[0003] Improving the ventilation and cooling efficiency of equipment compartments has become an urgent problem. Current research has investigated various influencing factors and operating conditions affecting ventilation and heat dissipation in train equipment compartments. However, proposed optimization measures require significant modifications to the compartment structure or internal layout. Upgrading the cooling system of high-speed trains necessitates prolonged downtime, resulting in high costs. Therefore, finding a way to improve the ventilation and cooling efficiency of equipment compartments without altering their original structure and layout is a pressing technical challenge. Summary of the Invention

[0004] This invention provides an independent air duct for the equipment compartment of a high-speed train. By adding an independent air duct to the equipment compartment, the traveling airflow is used to dissipate heat from key heat-generating equipment inside the compartment. This can improve the cooling efficiency of the equipment compartment without increasing the fan power or changing the original equipment compartment structure and equipment layout, thus ensuring the normal operation of the electrical equipment inside the compartment.

[0005] The specific technical solution is as follows:

[0006] An independent air duct for a high-speed train equipment compartment includes two contraction sections and one stabilization section. The contraction sections are symmetrically arranged at both ends of the stabilization section. One contraction section is provided with an air inlet and the other contraction section is provided with an air outlet. The independent air duct for the high-speed train equipment compartment is installed inside the equipment compartment, and the heat dissipation unit for the heat-generating equipment inside the equipment compartment is located in the stabilization section.

[0007] The airflow refers to the air that moves relative to the high-speed train during its operation due to friction and viscosity. As the distance along the train's normal direction increases, the relative speed between the air and the train also gradually increases. At a certain normal distance, the relative speed equals the train's speed relative to the ground.

[0008] like Figure 1 As shown, the current cooling method for the equipment compartments of high-speed trains is mainly forced air cooling. The insufficient cooling efficiency is mainly due to the inadequate utilization of the running airflow. The existing ventilation openings in the equipment compartments are arranged perpendicular to the surface of the train's equipment compartments, which is not conducive to adjusting the path of the running airflow. However, making significant changes to the structure or layout of the equipment compartments would be too costly. If the heat dissipation capacity of the forced air cooling fans is to be improved, the operating power of the fans needs to be increased, which will not only increase energy consumption, but also increase the heat generated by the fans themselves with the increase in power.

[0009] Therefore, this invention proposes an independent air duct, added within the equipment compartment. The air inlet introduces the airflow generated during train operation into the independent air duct, which is then accelerated through the contraction section and directed to the heat dissipation units of the main electrical equipment. This improves the cooling efficiency of key heat-generating equipment and reduces the operating load on the forced-air cooling fan, thereby lowering energy consumption. Furthermore, the independent air duct has a symmetrical structure, meeting the needs of bidirectional train operation: in the forward direction, the airflow flows in and out of the air inlet; in the reverse direction, the airflow flows in and out of the air outlet.

[0010] This invention utilizes the influence of the train's streamlined structure on the ambient airflow to add independent air ducts for key heat-generating equipment in the equipment compartment. Without altering the original equipment compartment structure and equipment layout, it can fully utilize the space inside the compartment, achieve full utilization of the traveling airflow, and improve the ventilation and cooling efficiency of key heat-generating equipment in the equipment compartment.

[0011] Furthermore, the stabilizing section is a square tube, and the contracting section includes an air collecting plate inclined relative to the sidewall of the stabilizing section. The air collecting plate improves the efficiency of collecting traveling airflow in the independent air duct.

[0012] Furthermore, the air collecting plate is one side of the contraction section, with one end connected to the stabilizing section. The inclination angle of the air collecting plate relative to the side wall of the stabilizing section is α, where α ∈ [20, 40]. To ensure that the air collecting plate does not interfere with the train skirt and to avoid the duct stabilizing section being too short to allow for the installation of the heat dissipation unit, α ∈ [20, 40].

[0013] Furthermore, α is 27°.

[0014] This invention simulates and analyzes air duct models with seven different fan angles (21°, 24°, 27°, 30°, 33°, 36°, and 39°), comparing the flow field streamline distribution, total pressure drop, and mass flow rate through the heat dissipation unit. As the fan angle increases, the pressure drop also increases, increasing by 19% from 21° to 39°. The mass flow rate initially increases, then decreases, and then increases again with increasing fan angle, with little difference between 27° and 33°. Based on the requirement of maximizing mass flow rate and minimizing pressure drop, and considering the flow field distribution, a fan angle of 27° was ultimately determined. When the train operates at other speeds or under other conditions, different fan angles can be used depending on the actual operating environment.

[0015] Furthermore, the contraction section includes a chamfered duct edge located between the air collecting plate and the sidewall of the stabilizing section. The chamfered duct edge reduces the pressure drop at the air inlet and outlet of the duct, resulting in a more uniform flow field within the duct.

[0016] Furthermore, the chamfer of the air duct is a straight surface.

[0017] This invention is based on a duct model with optimized air intake plate angles, and optimizes the duct chamfer using an adjoint shape optimization method. Adjoint shape optimization is a shape sensitivity-based optimization method that calculates the impact of shape on performance and then adjusts the shape to maximize or minimize a specific objective. This invention uses the total pressure drop constraint of the duct to design the optimization problem. The specific steps of the adjoint shape optimization workflow are: specifying the duct deformation boundary → determining the mesh deformation boundary conditions → solving the physics → calculating the target surface sensitivity → calculating the boundary displacement → performing mesh deformation → rerunning the original solution and the adjoint solution, and finally outputting the optimized model after several iterations. In a preferred embodiment of this invention, the independent duct wall uses a surface sensitivity model to output the optimized model after the 47th iteration. The surface most sensitive to duct pressure drop is located at the angle between the duct inlet section and the stable section, with a maximum deformation of 14mm. When selecting the wall, considering the difficulty in processing locally small-deformation curved surfaces during actual manufacturing, the optimized surface structure is approximated with a straight surface. The shape design method used is to create chamfers at the duct corners with the highest sensitivity. Simulation analysis of the optimized air duct structure showed that the pressure drop at the inlet and outlet of the optimized air duct was reduced by 7.2% compared to the unoptimized air duct. When the train operates at other speeds or under other conditions, chamfers of different sizes can be designed according to the actual operating environment.

[0018] Furthermore, the heat dissipation unit is a component of one side wall of the stable section. This configuration can be used when the heat dissipation unit of the heat-generating device is too large.

[0019] Furthermore, the independent air ducts of the high-speed train equipment compartment are arranged in pairs and symmetrically within the equipment compartment. Arranging the two independent air ducts of the high-speed train equipment compartment in pairs can increase the amount of airflow collected during operation and increase the total area of ​​the heat dissipation unit, thereby improving the ventilation and cooling efficiency of the heat-generating equipment. Attached Figure Description

[0020] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0021] Figure 1 A schematic diagram of airflow in the equipment compartment of an existing high-speed train;

[0022] Figure 2 This is a three-dimensional structural diagram of an equipment compartment equipped with an independent air duct for a high-speed train equipment compartment, according to an embodiment of the present invention.

[0023] Figure 3 This is a schematic diagram of the independent air duct in the high-speed train equipment compartment according to an embodiment of the present invention;

[0024] Figure 4 This is a schematic diagram of the chamfering of the independent air duct in the high-speed train equipment compartment according to an embodiment of the present invention;

[0025] Figure 5 This is a schematic diagram of the chamfer shape design of the independent air duct in the high-speed train equipment compartment according to an embodiment of the present invention;

[0026] Figure 6 This is a schematic diagram of airflow in the equipment compartment of a high-speed train equipped with an independent air duct according to an embodiment of the present invention.

[0027] 1. Equipment compartment; 2. Heating equipment; 3. Air inlet; 4. Independent air duct for high-speed train equipment compartment; 5. Air outlet; 6. Air collection plate; 7. Air duct chamfer; 8. Contraction section; 9. Heat dissipation unit for heating equipment; 10. Stabilization section; 11. Original air duct chamfer. Detailed Implementation

[0028] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be noted that, unless otherwise stated, the accompanying drawings and embodiments are only for illustrating and explaining preferred embodiments of the present invention, and are not intended to limit the invention. The present invention includes, but is not limited to, the content of the accompanying drawings and embodiments, which will not be repeated hereafter.

[0029] See Figure 2 One specific embodiment of the present invention is as follows: Independent air ducts 4 of the high-speed train equipment compartment are installed in pairs on both sides inside the equipment compartment 1, close to the heat-generating equipment 2. The outer frames of the air inlet 3 and the air outlet 5 are directly connected to the inner frame of the grille of the equipment compartment body 1 and are fixed by welding.

[0030] See Figure 3 The independent air duct 4 in the high-speed train equipment compartment is a tubular channel, comprising two contraction sections 8 and one stabilizing section 10. The two contraction sections 8 are symmetrically connected to both ends of the stabilizing section 10 and are fixed by welding. Each of the two contraction sections 8 is provided with an air inlet 3 and an air outlet 5. Each contraction section 8 is also provided with an air collecting plate 6 and an air duct chamfer 7. The inclination angle α of the air collecting plate 6 relative to the side wall of the stabilizing section 10 is 27°. The heat dissipation unit 9 of the heat-generating equipment is arranged in the stabilizing section 10 and fixed by a welded fixing groove, or other tightly connected and easily disassembled fixing methods.

[0031] See Figure 4 and Figure 5 The chamfer 7 of the air duct is located at the connection between the air collecting plate 6 and the side wall of the stabilizing section 10, which is the corner position of the air duct with the highest sensitivity. Using a shape design method, a design area is drawn with the intersection of the angle between the two walls of the original shape as the center and the maximum deformation l as the radius, where l = 14 mm. Starting from the center of the design area, perpendicular lines are drawn from the direction perpendicular to the top contour lines of the two walls in the original structure towards the circumference of the area, obtaining two intersection points with the circumference. Connecting these intersection points and extending them outwards to intersect the top contour lines of the two walls of the original structure, the plane formed by this line segment in the vertical direction intersecting the two walls of the original structure's design area is taken as the final optimized structure. Considering that the train travels in both directions during actual operation, similar treatment is applied to the air duct structures on both sides.

[0032] When the train is running:

[0033] Air inlet 3 introduces the airflow generated during train operation into the independent air duct 4 of the high-speed train equipment compartment. After being accelerated by the contraction section 8, the airflow flows onto the heat dissipation unit 9 of the heat-generating equipment located in the stabilization section 10 and flows out from the air outlet 5. This process can achieve efficient cooling of the heat-generating equipment 2.

[0034] See Figure 1 The high-speed train was not equipped with the independent air duct of the equipment compartment according to the embodiment of the present invention. When the train speed was 350km / h, the maximum inflow mass flow rate of each ventilation opening in the equipment compartment of the middle car of a certain type of 8-car high-speed train was 0.77kg / s, and the mass flow rate through the converter heat dissipation unit was 2.2kg / s.

[0035] See Figure 6 After the high-speed train is equipped with the independent air duct of the equipment compartment according to the embodiment of the present invention, when the running speed is 350km / h, the total mass flow rate in the equipment compartment can reach a maximum of 8.67kg / s, an increase of 183%, and the mass flow rate flowing through the heat dissipation unit of the transformer box can reach 3.79kg / s, an increase of 72%.

Claims

1. An independent ventilation duct for the equipment compartment of a high-speed train, characterized in that, It includes two contraction sections (8) and one stabilization section (10). The contraction sections (8) are symmetrically arranged at both ends of the stabilization section (10). One contraction section (8) is provided with an air inlet (3) and the other contraction section (8) is provided with an air outlet (5). The independent air duct (4) of the high-speed train equipment compartment is installed in the equipment compartment (1). The heat dissipation unit (9) of the heat-generating equipment in the equipment compartment (1) is located in the stabilization section (10). The stabilization section (10) is a square tube. The contraction section (8) includes an air collecting plate (6) that is inclined relative to the side wall of the stabilization section (10). The air collecting plate (6) 6) One end is connected to the air inlet (3), and the other end is connected to the stabilizing section (10). The inclination angle of the air collecting plate (6) relative to the side wall of the stabilizing section (10) is α, where α ∈ [20, 40]°. The contraction section (8) includes a duct chamfer (7) between the air collecting plate (6) and the side wall of the stabilizing section (10). The duct chamfer (7) is optimized by an accompanying shape optimization method. The accompanying shape optimization method is based on a duct model designed with the total pressure drop constraint of the independent duct of the equipment compartment, and obtains the preferred surface structure and maximum deformation of the duct chamfer (7). l Considering the difficulty in processing locally deformable curved surfaces during actual manufacturing, the preferred curved surface structure is approximated by a flat surface, i.e.: The chamfer (7) of the air duct is opened at the connection between the two walls of the air collecting plate (6) and the stabilizing section (10). With the intersection of the top angle of the two walls as the center and the maximum deformation l as the radius, draw a circle on the plane where the top contour lines of the two walls are located. Starting from the center of the circle, draw perpendicular lines to the circumference in the direction perpendicular to the top contour lines of the two walls respectively to obtain two intersection points with the circumference. Connect the intersection points and extend them outward to intersect the top contour lines of the two walls to obtain a line segment. Extend this line segment to form a plane that intersects the two walls. This plane is perpendicular to the two walls and is the same plane. This plane is the straight surface adopted by the chamfer (7) of the air duct.

2. The independent ventilation duct for a high-speed train equipment compartment according to claim 1, characterized in that, α is 27°.

3. The independent ventilation duct for the high-speed train equipment compartment according to any one of claims 1-2, characterized in that, The heat dissipation unit (9) of the heat-generating device is a component of the side wall of the stable section (10).

4. The independent ventilation duct for the high-speed train equipment compartment according to any one of claims 1-2, characterized in that, The independent air ducts (4) of the high-speed train equipment compartment are installed in pairs and symmetrically on both sides of the equipment compartment (1).

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