Cooling system for traction converter of electric locomotive

Abstract

The invention relates to the technical field of rail transit, in particular to an electric locomotive traction converter cooling system which comprises an evaporator cluster, a condenser cluster and a pipeline module. The evaporator cluster is used for being installed in a vehicle body, the evaporator cluster is used for installing an insulated gate bipolar transistor module, and the condenser cluster is used for being installed on the top of the vehicle body; the pipeline module comprises an ascending pipeline assembly and a descending pipeline assembly, a working medium absorbing heat of the insulated gate bipolar transistor module in the evaporator flows to the condenser cluster through the ascending pipeline assembly, and the working medium in the condenser cluster flows back to the evaporator cluster through the descending pipeline assembly after heat dissipation. The technical problem that an existing forced air cooling and liquid cooling system has inherent limitations on energy efficiency ratio, space adaptability and thermal failure risk control is solved.

Description

Technical Field

[0001] This invention relates to the field of rail transit technology, and in particular to a cooling system for a traction converter of an electric locomotive. Background Technology

[0002] As the power density and efficiency of heavy-duty locomotives continue to improve, the heat flux density of IGBT (Insulated Gate Bipolar Transistor) modules, the core power devices of their traction systems, is constantly increasing, while the physical space available for heat dissipation is becoming increasingly limited. This poses a more severe challenge to the performance stability and thermal management capabilities of the traction converter, a key component of traction power. Traditional air cooling and single-phase liquid cooling methods often struggle to simultaneously meet multiple requirements such as efficient heat dissipation, system lightweighting, and low operating noise when dealing with high heat loads, thus hindering the performance improvement and energy efficiency optimization of next-generation locomotives.

[0003] Phase change cooling technology, with its high heat transfer efficiency and excellent heat flux density adaptability, is considered a highly promising next-generation cooling solution and is expected to be applied to the thermal management of traction converters in electric locomotives. However, its application in the rail transit field is still in the initial exploratory stage, currently only seen in experimental applications in some low-power distributed devices, and has not yet been widely promoted in high-power traction systems.

[0004] On the other hand, using the "running wind" generated during train operation to cool the radiator can effectively reduce the cooling system's dependence on fans, thereby reducing energy consumption and noise. However, this method is constrained by multiple factors such as operating speed, environmental conditions, and spatial layout, and the stability and controllability of heat dissipation face challenges. Currently, it is also difficult to directly apply to high-power, high-reliability traction heat dissipation scenarios.

[0005] Therefore, there is an urgent need for a cooling system that combines efficient heat dissipation, lightweight design, and low noise to solve the above-mentioned technical problems. Summary of the Invention

[0006] The main objective of this invention is to provide a cooling system for the traction converter of electric locomotives, which aims to solve the inherent limitations of existing forced air cooling and liquid cooling systems in terms of energy efficiency ratio, space adaptability, and thermal failure risk control.

[0007] To achieve the above objectives, the present invention proposes a cooling system for a traction converter of an electric locomotive, comprising an evaporator cluster, a condenser cluster, and a piping module. The evaporator cluster is used for installation within the vehicle body and for mounting an insulated-gate bipolar transistor (IGBT) module. The condenser cluster is used for installation on the top of the vehicle body. The piping module includes an ascending pipe assembly and a descending pipe assembly. The working fluid in the evaporator, having absorbed heat from the IGBT module, flows through the ascending pipe assembly to the condenser cluster. After dissipating heat, the working fluid in the condenser cluster flows back to the evaporator cluster through the descending pipe assembly.

[0008] A further improvement of the electric locomotive traction converter cooling system of the present invention is that the condenser cluster includes multiple condensers arranged in a staggered manner, and each condenser is connected to the rising pipe assembly and the falling pipe assembly.

[0009] A further improvement of the electric locomotive traction converter cooling system of the present invention is that the evaporator cluster includes multiple evaporators arranged side by side, and the evaporators are used for bonding and mounting insulated gate bipolar transistor modules.

[0010] A further improvement of the electric locomotive traction converter cooling system of the present invention is that the evaporator is provided with multiple evaporation channels, and the angle between the evaporation channels and the horizontal plane is between 16° and 20°.

[0011] A further improvement of the electric locomotive traction converter cooling system of the present invention is that the angle between the gas collection zone at the outlet of the evaporator and the gas collection zone at the inlet of the evaporator is between 140° and 150°.

[0012] A further improvement of the electric locomotive traction converter cooling system of the present invention is that the riser pipe assembly includes an evaporator outlet pipe, an evaporator outlet main pipe, a riser pipe, a condenser inlet main pipe, and a condenser inlet pipe connected in sequence. The evaporator outlet pipe is connected to the evaporator, and the condenser inlet pipe is connected to the condenser.

[0013] A further improvement of the electric locomotive traction converter cooling system of the present invention is that the downcomer assembly includes a condenser outlet pipe, a condenser outlet main pipe, a downcomer, an evaporator inlet main pipe, and an evaporator inlet pipe connected in sequence, the evaporator inlet pipe being connected to the evaporator, and the condenser outlet pipe being connected to the condenser.

[0014] A further improvement of the electric locomotive traction converter cooling system of the present invention is that the diameters of the evaporator inlet pipe, the evaporator outlet pipe, the condenser inlet pipe, and the condenser outlet pipe are between 25 mm and 35 mm.

[0015] A further improvement of the electric locomotive traction converter cooling system of the present invention is that the diameter of the condenser outlet main pipe and the condenser inlet main pipe is between 55mm and 65mm, and the diameter of the evaporator outlet main pipe and the evaporator inlet main pipe is between 75mm and 85mm.

[0016] A further improvement of the electric locomotive traction converter cooling system of the present invention is that the outlet dryness of the evaporator is 0.5.

[0017] The technical solution of the present invention has the following beneficial effects: The electric locomotive traction converter cooling system of the present invention cools the IGBT module by installing a cluster of condensers on the top of the car body. When the high-speed train is running at high speed, the heat generated by the IGBT (Insulated Gate Bipolar Transistor) module is transferred to the condenser through the evaporator. Then, under the action of the running air, the heat is dissipated into the air, thereby cooling the IGBT module of the converter. This solves the inherent limitations of existing forced air cooling and liquid cooling systems in terms of energy efficiency ratio, space adaptability, and thermal failure risk control.

[0018] This invention has an inherent advantage in terms of lightweight design, as it eliminates the need for ventilators and water pumps, thereby reducing the weight of equipment in the machinery room and lowering the basic energy consumption of locomotive operation. Secondly, it provides space for locomotives to "increase load" (increase passenger / cargo capacity) or allows the installation of other functional equipment while meeting axle load restrictions. The resulting economic benefits are long-term and continuous savings in operating costs and increased transport capacity.

[0019] The present invention has a small number of structural components and the noise level of the equipment is far lower than that of a general cooling system. Therefore, there is no need to install expensive silencing equipment or complex soundproof cover structures, which reduces the difficulty of early research and development and design, and also significantly reduces manufacturing costs and the complexity of later maintenance. It is more suitable for trains passing through urban centers, near residential areas, or running on lines that are extremely sensitive to noise, such as nighttime operating sections. Low-noise vehicles are more likely to meet environmental protection requirements, reduce interference to surrounding communities, and thus effectively improve public acceptance and social adaptability of operation.

[0020] The invention has a relatively simple overall structure, mature and reliable production process, and a high degree of standardization and generalization of components, thereby effectively reducing the procurement cost of raw materials and the assembly complexity on the production line. Attached Figure Description

[0021] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0022] Figure 1 This is a schematic diagram of the cooling system for the traction converter of an electric locomotive according to the present invention (A is the direction of travel). Figure 2 This is a projection diagram of the condenser roof position arrangement of the cooling system of the electric locomotive traction converter of the present invention (B is the steam inlet direction, and C is the condensate outlet direction). Figure 3 This is a schematic diagram of the IBGT installation of the electric locomotive traction converter cooling system of the present invention; Figure 4 This is a schematic diagram of the internal flow channel of the evaporator in the cooling system of the electric locomotive traction converter of the present invention; Figure 5 This is a schematic diagram of a partial flow channel in the evaporator of the electric locomotive traction converter cooling system of the present invention. Figure 1 ; Figure 6 This is a schematic diagram of a partial flow channel in the evaporator of the electric locomotive traction converter cooling system of the present invention. Figure 2 ; Figure 7 Schematic diagram of the initial position for condenser layout optimization; Figure 8 This is a W-shaped distribution diagram of the condenser cluster in the cooling system of the electric locomotive traction converter of the present invention.

[0023] Explanation of icon numbers: 101. Evaporator cluster; 102. Insulated gate bipolar transistor module; 103. Evaporator outlet pipe; 104. Evaporator outlet main pipe; 105. Riser pipe; 106. Condenser inlet main pipe; 107. Condenser inlet pipe; 108. Condenser cluster; 109. Condenser outlet pipe; 110. Condenser outlet main pipe; 111. Downcomer pipe; 112. Evaporator inlet pipe; 113. Vehicle body; 114. Traveling air; 115. Evaporator outlet; 116. Evaporator inlet; 118. Evaporation channel; 119. Fins; 120. Reserved flow area; 121. Mounting hole. Detailed Implementation

[0024] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0025] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indication will also change accordingly.

[0026] Furthermore, in this invention, descriptions involving "first," "second," etc., are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0027] In this invention, unless otherwise explicitly specified and limited, the terms "connection," "fixed," etc., should be interpreted broadly. For example, "fixed" can mean a fixed connection, a detachable connection, or an integral part; it can mean a mechanical connection or an electrical connection; it can mean a direct connection or an indirect connection through an intermediate medium; it can mean the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0028] Furthermore, the technical solutions of the various embodiments of the present invention can be combined with each other, but only if they are feasible for those skilled in the art. If the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by the present invention.

[0029] Under normal train operating conditions, the total heat dissipation of the traction converter IGBT (Insulated Gate Bipolar Transistor) module is 68kW, with a total of 36 IGBT units. The maximum heat loss power of a single IGBT unit is 1.89kW, and the heat-receiving area is 0.0192m². 2 The module's thermal density is 98.5 kW / m³. 2 The cooling system must, under rated operating conditions, ensure the safe operation of the converter by meeting the following requirements: with an ambient temperature of 40°C, the maximum allowable junction temperature of the IGBT must not exceed 125°C, and the surface temperature of the IGBT module must not exceed 90°C.

[0030] like Figures 1-6As shown, the present invention proposes a cooling system for a traction converter of an electric locomotive, including an evaporator cluster 101, a condenser cluster 108, and a piping module. The evaporator cluster 101 is installed inside the car body 113 and is used to house an insulated-gate bipolar transistor module 102. The condenser cluster 108 is installed on the top of the car body 113. The piping module includes an ascending pipe assembly and a descending pipe assembly. The working fluid in the evaporator that absorbs heat from the insulated-gate bipolar transistor module 102 flows through the ascending pipe assembly to the condenser cluster 108. After the working fluid in the condenser cluster 108 dissipates heat, it flows back to the evaporator cluster 101 through the descending pipe assembly.

[0031] To ensure that the surface temperature of the IGBT at the evaporation end does not exceed 90°C, the superheat of the system is set to 21.58°C based on the evaporation and condensation characteristics. Therefore, a certain margin is reserved at an ambient temperature of 40°C, and the saturation temperature of the working fluid in the evaporator of the cooling system of this invention is set to ≤65°C.

[0032] Preferably, the condenser cluster 108 includes multiple condensers arranged in a staggered "W" shape, with each condenser connected to both the rising pipe assembly and the falling pipe assembly. This staggered arrangement fully utilizes the high-speed separated airflow on both sides of the first two rows of condensers to enhance the incoming flow velocity of the rear condensers, thereby increasing the total heat exchange of the system. The Pearson correlation coefficient between the condenser arrangement parameters and the heat exchange shows that the displacement X1 of the first row of condensers has a moderate positive correlation with the heat exchange, while the distance between the third row of condensers and the second row has a weak positive correlation with the heat exchange. Utilizing this characteristic, the arrangement of the condensers can be adjusted based on the structural features of the vehicle body 113.

[0033] To meet the heat dissipation requirements of the IGBTs in the traction converter of electric locomotives, five sets of condensers are needed. However, the heat dissipation efficiency of the condensers is closely related to their arrangement due to the influence of airflow direction and bypass effect. Therefore, to improve the heat dissipation efficiency of the condenser cluster, the arrangement of the condensers needs to be optimized.

[0034] Table 1. Condenser Relative Position Parameters

[0035] The initial position for optimizing the condenser layout is as follows: Figure 7 As shown. Considering the symmetry of the condenser arrangement, the optimization process only considers the relative positions of condenser 1, condenser 2, and condenser 3, and the degrees of freedom for the movement of condenser 1 and condenser 3 are... direction and Direction, condenser 2 in The condenser arrangement is shifted in direction. Therefore, there are five parameters for optimizing the condenser layout: the first and third rows of condensers... Displacement in direction ( , The first and third rows of condensers are in Displacement in direction ( , The second row of condensers is in Displacement in direction ( Due to the limitations of the electric locomotive's body structure, the range of values ​​for the optimization parameters is shown in Table 1. for The range of directional displacement. for The range of directional displacement.

[0036] To understand the impact of condenser location parameters on heat transfer, the Pearson correlation coefficient was used. An assessment will be conducted. Between [-1, 1], the closer the value is to 1 or -1, the stronger the positive or negative correlation; the closer it is to 0, the weaker the correlation.

[0037] Let the position parameter of the condenser be the independent variable, and use It means, that is , , as well as Total calories are the dependent variable, using Indicates the Pearson correlation coefficient. The specific calculation method is as follows: ; In the formula, K k and J j,k These are the dependent variables. K and independent variable Jj The k Each sample value; and These are the dependent variables. K and independent variable Jj The sample mean; N This refers to the sample size. The adjusted W-shaped distribution of the condenser cluster is as follows: Figure 8 As shown.

[0038] Preferably, the evaporator cluster 101 includes multiple evaporators arranged side-by-side. These evaporators are used for mounting insulated-gate bipolar transistor (IGBT) modules 102. In this embodiment, the evaporator is made of aluminum alloy and is formed by brazing the evaporator body and cover plate. The evaporator is mounted on the converter cabinet via bolts on both sides. Considering the pressure resistance of the evaporator, the thickness of the cover plate and the back plate of the main body is set to 4mm. The IGBT modules are uniformly fixed to the evaporator body via threaded connections. The evaporator inlet 116 is located at the bottom, and the evaporator outlet 115 is located at the top. To reduce the space occupied by the evaporator cluster 101, the gap between the upper and lower IGBTs is set to 10mm, and the left and right center dimensions are set to 50mm. Six IGBT modules are centrally located on one evaporator cold plate. Therefore, each evaporator needs to remove the heat dissipation of six IGBT (Insulated-Gate Bipolar Transistor) module chips. Five sets of condensers are used to transfer the heat of the working fluid to the environment through the circulating fan 114, achieving the purpose of cooling.

[0039] Preferably, the evaporator is provided with multiple evaporation channels 118, and the angle between the evaporation channels 118 and the horizontal plane is between 16° and 20°. In this embodiment, six IGBT modules with dimensions of 160×120×38mm are installed on the outer surface of the side sealing plate of the evaporator. Evaporation channels 118 are provided in the mounting area of ​​the IGBT bottom surface, with 35 evaporation channels 118 in the mounting area of ​​each IGBT module. The dimensions of the evaporation channels 118 are 126 mm × 4 mm × 32 mm, and the thickness of the fins 119 is 1 mm. At the same time, in order to avoid the mounting holes 121 of the IGBT (Insulated Gate Bipolar Transistor) modules, the angle between the evaporation channels 118 and the horizontal plane is 18°. Furthermore, a reserved flow area 120 is provided on the evaporator at the mounting holes 121 of the IGBT (Insulated Gate Bipolar Transistor) modules, thereby facilitating the flow of the working fluid in the evaporator and accelerating the removal of heat.

[0040] Specifically, the angle between the gas collection zone at the evaporator outlet 115 and the gas collection zone at the evaporator inlet is between 140° and 150°, preferably 145°, thereby better realizing heat exchange between the IGBT and the evaporator working fluid. Preferably, the riser assembly includes an evaporator outlet pipe 103, an evaporator outlet main pipe 104, a riser pipe 105, a condenser inlet main pipe 106, and a condenser inlet pipe 107 connected in sequence. The evaporator outlet pipe 103 is connected to the evaporator, and the condenser inlet pipe 107 is connected to the condenser.

[0041] Preferably, the downcomer assembly includes a condenser outlet pipe 109, a condenser outlet main pipe 110, a downcomer 111, an evaporator inlet main pipe 116, and an evaporator inlet pipe 112 connected in sequence. The evaporator inlet pipe 112 is connected to the evaporator, and the condenser outlet pipe 109 is connected to the condenser. By branching the riser and downcomer assemblies, the flow rate can be increased or decreased when the working fluid converges or diverges in the pipe network. The flow process is more complex than when the working fluid flow rate in a single riser pipe 105 or downcomer 111 remains unchanged with the flow of the working fluid. This ensures the maintainability of the entire cooling system in the vehicle, the stability of system operation, and the accuracy of the status data of the monitoring system.

[0042] Specifically, the diameters of the evaporator inlet pipe 112, the evaporator outlet pipe 103, the condenser inlet pipe 107, and the condenser outlet pipe 109 are between 25mm and 35mm, preferably 30mm.

[0043] Specifically, the diameters of the condenser outlet main pipe 110 and the condenser inlet main pipe 106 are between 55mm and 65mm, preferably 60mm; the diameters of the evaporator outlet main pipe 104 and the evaporator inlet main pipe 116 are between 75mm and 85mm, preferably 80mm.

[0044] Preferably, the evaporator outlet dryness fraction is 0.5. Evaporator outlet dryness fraction (115) refers to the proportion of the refrigerant's mass at the evaporator outlet (115) to its total mass, ranging from 0 (all saturated liquid) to 1 (all saturated vapor). In the evaporator, the refrigerant absorbs heat and gradually evaporates from a saturated liquid; the outlet dryness fraction reflects the degree of completion of the evaporation process. In this embodiment, the evaporator outlet dryness fraction is 0.5, which is a moderate level, further optimizing heat exchange performance and avoiding system flow instability and heat transfer deterioration.

[0045] This invention has an inherent advantage in terms of lightweight design, as it eliminates the need for ventilators and water pumps, thereby reducing the weight of equipment in the machinery room and lowering the basic energy consumption of locomotive operation. Secondly, it provides space for locomotives to "increase load" (increase passenger / freight capacity) or allows the installation of other functional equipment while meeting axle load restrictions. The resulting economic benefits are long-term and continuous savings in operating costs and increased transport capacity, and this value should be included in the full life cycle cost accounting.

[0046] This invention has great potential for technology transfer and platformization. If successfully applied to electric locomotives, its technology platform can be adapted to urban rail vehicles, high-speed trains, and even new energy vehicles and ship propulsion systems at low cost, thereby maximizing the benefits of R&D investment.

[0047] Table 2 Comparison and Analysis of System Lightweighting

[0048] The above description is only a preferred embodiment of the present invention and does not limit the scope of the present invention. All equivalent structural transformations made under the inventive concept of the present invention using the contents of the present invention specification and drawings, or direct / indirect applications in other related technical fields, are included within the protection scope of the present invention.

Claims

1. A cooling system for a traction converter of an electric locomotive, characterized in that, The application relates to a refrigeration system for a vehicle, which comprises an evaporator cluster (101), a condenser cluster (108) and a pipeline module; the evaporator cluster (101) is arranged in a vehicle body (113) and is used for mounting an insulated gate bipolar transistor module (102); the condenser cluster (108) is arranged on the top of the vehicle body (113); the pipeline module comprises an ascending pipeline assembly and a descending pipeline assembly; working medium, which absorbs heat of the insulated gate bipolar transistor module (102) in the evaporator, flows to the condenser cluster (108) through the ascending pipeline assembly; and the working medium in the condenser cluster (108) flows back to the evaporator cluster (101) through the descending pipeline assembly after heat dissipation.

2. The electric locomotive traction converter cooling system of claim 1, wherein, The condenser cluster (108) comprises a plurality of condensers which are arranged staggeredly; each condenser is connected to the ascending pipeline assembly and the descending pipeline assembly.

3. The electric locomotive traction converter cooling system of claim 2, wherein, The evaporator cluster (101) comprises a plurality of evaporators which are arranged side by side; the evaporators are used for mounting the insulated gate bipolar transistor module (102) in a clamping mode.

4. The electric locomotive traction converter cooling system of claim 3, wherein, A plurality of evaporation channels (118) are arranged on the evaporator; the included angle between the evaporation channels (118) and a horizontal plane is 16-20 degrees.

5. The electric locomotive traction converter cooling system of claim 4, wherein, The included angle between the gas collection area of the evaporator outlet (115) and the gas collection area of the evaporator inlet is 140-150 degrees.

6. The electric locomotive traction converter cooling system of claim 3, wherein, The ascending pipeline assembly comprises an evaporator outlet pipeline (103), an evaporator outlet main pipeline (104), an ascending pipeline (105), a condenser inlet main pipeline (106) and a condenser inlet pipeline (107) which are connected in sequence; the evaporator outlet pipeline (103) is connected to the evaporator; and the condenser inlet pipeline (107) is connected to the condenser.

7. The electric locomotive traction converter cooling system of claim 6, wherein, The descending pipeline assembly comprises a condenser outlet pipeline (109), a condenser outlet main pipeline (110), a descending pipeline (111), an evaporator inlet (116) main pipeline and an evaporator inlet pipeline (112) which are connected in sequence; the evaporator inlet pipeline (112) is connected to the evaporator; and the condenser outlet pipeline (109) is connected to the condenser.

8. The electric locomotive traction converter cooling system of claim 7, wherein, The diameters of the evaporator inlet pipeline (112), the evaporator outlet pipeline (103), the condenser inlet pipeline (107) and the condenser outlet pipeline (109) are 25-35 mm.

9. The electric locomotive traction converter cooling system of claim 7, wherein, The diameters of the condenser outlet main pipeline (110) and the condenser inlet main pipeline (106) are 55-65 mm; and the diameters of the evaporator outlet main pipeline (104) and the evaporator inlet (116) main pipeline are 75-85 mm.

10. The electric locomotive traction converter cooling system of claim 1, wherein, The outlet dryness of the evaporator is 0.5.

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