Segmented work asymmetric dual-flow scroll and method

Abstract

Segmented work asymmetric double flow channel scroll and method, it relates to turbocharger technical field.Segmented work asymmetric double flow channel scroll, including scroll;The scroll is equipped with turbine cavity, the first flow channel and the second flow channel are separated through the isolation wall and are equipped with in the turbine cavity periphery, the first flow channel rear end is connected to the turbine cavity through the arc-shaped air outlet A, the second flow channel rear end is connected to the turbine cavity through the arc-shaped air outlet B, and air outlet A and air outlet B respectively occupy 180 ° circumferential angle and no overlap.A kind of scroll double flow channel segmented work control method, including low-speed operating condition control method, high-speed operating condition control method and transition operating condition control method.The present application is by enabling small cross-sectional area flow channel under low-speed operating condition, concentrates exhaust gas pulse energy, makes turbine response time shorten, improves acceleration delay.Enabling large cross-sectional area flow channel under high-speed operating condition, provides sufficient exhaust gas flow, makes turbine power promotion, satisfies engine high-power output demand.

Description

Technical Field

[0001] This invention relates to the field of turbocharger technology, and in particular to a segmented power-generating asymmetric dual-flow-channel vortex housing and method. Background Technology

[0002] With increasingly stringent energy conservation and emission reduction regulations, turbocharging technology has become a core means for improving power density and reducing fuel consumption in internal combustion engines. Among them, the twin-scroll housing, which can effectively isolate exhaust pulses from each cylinder of the engine and reduce airflow interference, thereby improving exhaust gas energy utilization, has been widely used in modern engines.

[0003] However, existing dual-flow-channel volute technology still has shortcomings in balancing engine performance under all operating conditions, mainly in the following aspects: 1. Symmetrical flow channel design, poor adaptability to operating conditions: Currently, most mainstream twin-scroll turbochargers employ a 1:1 symmetrical flow channel area (or throat area, flow passage area) design (such as the BorgWarner two-way flow channel turbocharger). This design has an inherent contradiction: under low-speed, low-flow conditions, an excessively large flow channel area leads to the dispersion of exhaust gas pulse energy, failing to form effective impact kinetic energy and causing turbo lag; while under high-speed, high-flow conditions, an excessively small flow channel area restricts exhaust gas flow capacity, resulting in increased exhaust back pressure and limiting the engine's high-speed power output. Existing technology struggles to simultaneously meet the requirements of "fast low-speed response" and "sufficient high-speed flow" in the same structure.

[0004] 2. Variable flow structures are complex and have low reliability: To address these issues, some existing technologies (such as variable geometry turbochargers (VGT) or switchable flow path designs) employ rotatable guide vanes or sliding sleeves to adjust the flow path area. While offering a wide adjustment range, these technologies introduce additional actuators, linkage mechanisms, and high-temperature sliding components. These moving parts not only increase manufacturing costs but are also highly susceptible to jamming, deformation, or failure under the harsh conditions of high engine temperatures and high-frequency vibrations, resulting in high failure rates and increased maintenance costs.

[0005] 3. Due to the lack of work segments, energy loss still exists: To address the issue of area symmetry, existing patents (such as CN207420708U) have proposed asymmetric dual-channel designs, optimizing flow matching by adjusting the area ratio of the two channels. However, such designs typically do not manage the circumferential segmentation of the airflow's work zone, and the two channels are often in a continuous state within a 360° range. This results in interference and mixing of exhaust pulses of different phases in the turbine circumferential direction, causing unnecessary loss of exhaust gas kinetic energy and failing to maximize the utilization of pulse energy.

[0006] 4. The traditional segmented flow channel design is disconnected from the flow channel area design: A few existing technologies attempt to introduce the concept of segmented power delivery (such as a 180° inner flow channel + a 360° outer flow channel), but because they are not combined with the asymmetrical design of the flow channel cross-sectional area, they cannot form a synergistic effect. Often, an unreasonable match occurs where "small flow channel does long power" or "large flow channel does short power," which cannot be optimized for exhaust characteristics at different engine speeds, resulting in uneven turbine stress and even negative torque, affecting the life of the rotor system.

[0007] In summary, there is an urgent need for a new type of vortex casing that is simple in structure, requires no additional control mechanism, and can solve problems such as slow response at low speeds, limited power at high speeds, severe airflow interference, and high manufacturing costs through optimized structural design. Summary of the Invention

[0008] The purpose of this invention is to overcome the shortcomings of the prior art and provide a segmented power-operating asymmetric dual-channel vortex housing and method. It solves the problem of poor adaptability to operating conditions caused by the symmetry of the flow channel area in existing dual-channel vortex housings, and breaks the contradiction between low-speed response and high-speed flow. It solves the problems of complex variable cross-section structure, low reliability and high cost, and eliminates moving parts. It solves the problems of airflow interference and energy loss caused by the lack of segmented management in asymmetric design, and the problem of uneven turbine force caused by the lack of a combined area ratio in traditional segmented flow channels, thus achieving efficient and stable operation under all operating conditions.

[0009] The technical solution of this invention is: a segmented, power-operating, asymmetric dual-flow-channel volute casing for a turbocharger, comprising a volute casing; a turbine cavity is provided inside the volute casing, with an outlet at one end of the turbine cavity; a first flow channel and a second flow channel are arranged around the turbine cavity on its outer periphery, the second flow channel is arranged around the outside of the first flow channel, the first flow channel and the second flow channel are separated from each other by an isolation wall; the front end of the first flow channel is connected to the outer surface of the volute casing to form an air inlet A, the front end of the second flow channel is connected to the outer surface of the volute casing to form an air inlet B; the rear end of the first flow channel is connected to the turbine cavity through an arc-shaped air outlet A, the rear end of the second flow channel is connected to the turbine cavity through an arc-shaped air outlet B; air outlet A and air outlet B each occupy a circumferential angle of 180° around the turbine cavity, the circumferential angles occupied by air outlet A and air outlet B do not overlap, thus jointly covering the complete circumferential angle around the turbine cavity; the minimum flow cross-sectional area of ​​the first flow channel is A1, the minimum flow cross-sectional area of ​​the second flow channel is A2, A1:A2=0.75~0.85:1.

[0010] A further technical solution of the present invention is as follows: the airflow in the first flow channel flows from the inlet B to the outlet B. Within the arcuate range of the outlet B, the shortest and longest positions of the air path from the inlet B are defined as 0° and 180°, respectively, and the range of 0-180° is defined as the first circumferential region; the airflow in the second flow channel flows from the inlet A to the outlet A. Within the arcuate range of the outlet A, the shortest and longest positions of the air path from the inlet A are 180° and 360°, respectively, and the range of 180-360° is defined as the second circumferential region.

[0011] A further technical solution of the present invention is as follows: the turbocharger is used in a four-cylinder engine, and the four cylinders inside the four-cylinder engine are named cylinder 1, cylinder 3, cylinder 4 and cylinder 2 respectively according to the firing order. The four-cylinder engine also includes an intake manifold A and an intake manifold B; wherein, cylinders 1 and 4 share an exhaust manifold A, and cylinders 2 and 3 share an exhaust manifold B; exhaust manifold A is connected to the intake port A of the second flow channel, and exhaust manifold B is connected to the intake port B of the first flow channel.

[0012] A further technical solution of the present invention is: defining the cross section perpendicular to the central axis of the turbine cavity as the cross section, the cross section profiles of the first flow channel and the second flow channel are involute curved surfaces, and the dimensional accuracy of the flow channel profile is ≤ ±0.2mm.

[0013] A further technical solution of the present invention is: the isolation wall between the first flow channel and the second flow channel is integrally cast with the vortex shell.

[0014] A further technical solution of the present invention is: A1: A2 = 0.8:1.

[0015] The technical solution of the present invention is: a segmented power control method for a vortex shell with dual flow channels, based on a segmented power asymmetric dual flow channel vortex shell, including a low-speed operating condition control method, a high-speed operating condition control method, and a transitional operating condition control method; The low-speed operating condition control method is as follows: The exhaust mass flow rate of the engine is relatively small. The exhaust gas of cylinders 1 and 4 enters the first flow channel and does work in the first circumferential area of ​​the rear section, driving the turbine to rotate. The exhaust gas of cylinders 2 and 3 enters the second flow channel. However, at this time, the high pulse energy of the first flow channel dominates the turbine to start rotating, the response is fast, the lag is reduced, and it is suitable for low-speed operating conditions. The high-speed operating condition control method is as follows: The engine exhaust mass flow rate is relatively large. The exhaust gas of cylinders 1 and 4 enters the first flow channel and does work in the first circumferential area of ​​the rear section. The exhaust gas of cylinders 2 and 3 enters the second flow channel and does work in the second circumferential area of ​​the rear section. Together they drive the turbine to rotate, meet the turbine speed requirements, and avoid the waste of energy caused by exhaust gas bypass. The transition condition control method is as follows: the first circumferential region and the second circumferential region together form a complete circumferential angle, so that the two power-operating regions are seamlessly connected, the turbine speed transitions smoothly, and there is no power interruption or impact.

[0016] Compared with the prior art, the present invention has the following advantages: 1. All-condition compatibility: Low-speed response: By using a small cross-sectional area flow channel (0.8 times the baseline) under low-speed conditions, the exhaust gas pulse energy is concentrated, which shortens the turbine response time by 15%-20% and significantly improves acceleration lag.

[0017] High-speed power: By using a large cross-sectional area flow channel (1.0 times the baseline) under high-speed conditions, sufficient exhaust gas flow is provided, which increases the turbine power by 10%-15% to meet the engine's high power output requirements.

[0018] 2. High energy efficiency: The 180° segmented closed design isolates the airflow between the two channels, avoids pulse interference, and reduces exhaust pulse energy loss by more than 25%, making it especially suitable for low-speed, high-torque operating conditions.

[0019] 3. Balancing reliability and cost: Simplified structure: It eliminates the complex connecting rods, blades and actuator mechanism of the variable geometry turbine (VGT), and is formed by integral casting, which reduces manufacturing costs by 10%-15% and reduces the failure rate by 30%.

[0020] Force balance: The two working areas are symmetrically distributed at 180°, the radial forces of the turbine cancel each other out, the vibration amplitude is reduced by 20%, and the bearing life is extended by 30%.

[0021] 4. Good versatility: With a standardized interface design, it can directly replace the existing symmetrical dual-flow volute housing and is compatible with four-cylinder, six-cylinder and other multi-cylinder engines without the need to modify the engine exhaust manifold and turbocharger mounting interface.

[0022] The present invention will be further described below with reference to the figures and embodiments. Attached Figure Description

[0023] Figure 1 This is a circumferential sectional view of the present invention; Figure 2 This is an external view of the present invention; Figure 3 for Figure 2 PP sectional view (axial 1); Figure 4 for Figure 2 NN-direction cross-sectional view (axis 2); Figure 5 This is a perspective view of the present invention.

[0024] Legend: Turbine cavity 1; First flow channel 2; Second flow channel 3; Isolation wall 4; Inlet A5; Inlet B6; Outlet A7; Outlet B8.

[0025] Additional notes: Figure 1 The red and blue areas are used to mark the arc-shaped ranges of air outlet A7 and air outlet B8, respectively. Detailed Implementation

[0026] Example 1: like Figure 1-5 As shown, a segmented power-acting asymmetric dual-flow-channel volute housing is used in turbochargers, including the volute housing.

[0027] The turbine housing contains a turbine cavity 1, with an outlet at one end. Around the turbine cavity are a first flow channel 2 (short, small-diameter channel) and a second flow channel 3 (long, large-diameter channel). The second flow channel 3 surrounds the first flow channel 2. The first and second flow channels 2 are separated by a partition wall 4. The front end of the first flow channel 2 connects to the outer surface of the turbine housing to form an air inlet A5. The front end of the second flow channel 3 connects to the outer surface of the turbine housing to form an air inlet B6. The rear end of the first flow channel 2 connects to the turbine cavity 1 through an arc-shaped air outlet A7. The rear end of the second flow channel 3 connects to the turbine cavity 1 through an arc-shaped air outlet B8. Air outlets A7 and B8 each occupy a circumferential angle of 180° around the turbine cavity 1. The circumferential angles occupied by air outlets A7 and B8 do not overlap, thus jointly covering a complete circumferential angle (360°) around the turbine cavity 1. The minimum flow cross-sectional area of ​​the first flow channel 2 is A1, and the minimum flow cross-sectional area of ​​the second flow channel 3 is A2, with A1:A2 = 0.8:1.

[0028] The airflow in the first flow channel 2 flows from the inlet B6 to the outlet B8. Within the arc-shaped range of the outlet B8, the shortest and longest positions of the air path from the inlet B6 are defined as 0° and 180°, respectively. The range of 0-180° is defined as the first circumferential region.

[0029] The airflow in the second flow channel 3 flows from the inlet A5 to the outlet A7. Within the arc-shaped range of the outlet A7, the shortest and longest distances from the inlet A5 are 180° and 360° respectively (360° coincides with 0°). The range of 180-360° is defined as the second circumferential region.

[0030] Preferably, the turbocharger is used in a four-cylinder engine. The four-cylinder engine names its four cylinders, cylinder 1, cylinder 3, cylinder 4, and cylinder 2, according to the firing order. The four-cylinder engine also includes an intake manifold A and an intake manifold B. Cylinders 1 and 4 share an exhaust manifold A, and cylinders 2 and 3 share an exhaust manifold B. Exhaust manifold A is connected to the intake port A5 of the second flow channel 3, and exhaust manifold B is connected to the intake port B6 of the first flow channel 2.

[0031] Preferably, the cross section perpendicular to the central axis of the turbine cavity 1 is defined as the cross section, the cross section profiles of the first flow channel 2 and the second flow channel 3 are involute curved surfaces, and the dimensional accuracy of the flow channel profiles of both is ≤ ±0.2mm.

[0032] Preferably, the isolation wall 4 located between the first flow channel 2 and the second flow channel 3 is integrally cast with the vortex shell.

[0033] Preferably, the volute casing is made of ductile iron or stainless steel, which can withstand exhaust gas temperatures of 600-1050℃ or higher.

[0034] A segmented power control method for a vortex-shell dual-channel vortex-shell, based on the aforementioned segmented power asymmetric dual-channel vortex-shell, includes a low-speed operating condition control method, a high-speed operating condition control method, and a transitional operating condition control method.

[0035] The low-speed operating condition control method is as follows: The exhaust mass flow rate of the engine is relatively small. The exhaust gas of cylinders 1 and 4 enters the first flow channel through the intake manifold A and does work in the first circumferential region (0-180°) of the rear section, driving the turbine to rotate. The exhaust gas of cylinders 2 and 3 enters the second flow channel through the intake manifold B. (At this time, because the front section of the second flow channel is closed, only a small amount of airflow does work in the second circumferential region (180-360°) of the rear section). However, at this time, the high pulse energy of the first flow channel dominates the turbine to start rotating, the response is rapid, the hysteresis is reduced, and it is suitable for low-speed operating conditions.

[0036] The high-speed operating condition control method is as follows: The exhaust mass flow rate of the engine is relatively large. The exhaust gas of cylinders 1 and 4 enters the first flow channel through intake manifold A and does work in the first circumferential region (0-180°) of the latter section. The exhaust gas of cylinders 2 and 3 enters the second flow channel through intake manifold B and does work in the second circumferential region of the latter section. Together, they drive the turbine to rotate, meet the turbine (high) speed requirements, and avoid the waste of energy caused by exhaust gas bypass.

[0037] The transition condition control method is as follows: the first circumferential region and the second circumferential region together form a complete circumferential angle, so that the two power-operating regions are seamlessly connected, the turbine speed transitions smoothly, and there is no power interruption or impact.

Claims

1. A segmented, power-acting, asymmetric dual-flow-channel volute housing for turbochargers, including the volute housing; its characteristics are: The turbine housing contains a turbine cavity with an outlet at one end. A first flow channel and a second flow channel are arranged around the turbine cavity. The second flow channel surrounds the outside of the first flow channel. The first and second flow channels are separated by a partition wall. The front end of the first flow channel connects to the outer surface of the turbine housing to form an inlet A, and the front end of the second flow channel connects to the outer surface of the turbine housing to form an inlet B. The rear end of the first flow channel connects to the turbine cavity through an arc-shaped outlet A, and the rear end of the second flow channel connects to the turbine cavity through an arc-shaped outlet B. Outlets A and B each occupy a 180° circumferential angle around the turbine cavity, and the circumferential angles occupied by outlets A and B do not overlap, thus jointly covering a complete circumferential angle around the turbine cavity. The minimum flow cross-sectional area of ​​the first flow channel is A1, and the minimum flow cross-sectional area of ​​the second flow channel is A2, where A1:A2 = 0.75–0.85:

1.

2. The segmented, work-performing, asymmetric dual-channel vortex shell as described in claim 1, characterized in that: The airflow in the first flow channel flows from inlet B to outlet B. Within the arc-shaped range of outlet B, the shortest and longest positions of the air path from inlet B are defined as 0° and 180°, respectively. The range of 0-180° is defined as the first circumferential region. The airflow in the second flow channel flows from inlet A to outlet A. Within the arc-shaped range of outlet A, the shortest and longest positions of the air path from inlet A are 180° and 360°, respectively. The range of 180-360° is defined as the second circumferential region.

3. The segmented, work-performing, asymmetric dual-channel vortex shell as described in claim 2, characterized in that: The turbocharger is used in a four-cylinder engine. The four-cylinder engine names its four cylinders as cylinder 1, cylinder 3, cylinder 4, and cylinder 2 according to the firing order. The four-cylinder engine also includes an intake manifold A and an intake manifold B. Cylinders 1 and 4 share an exhaust manifold A, and cylinders 2 and 3 share an exhaust manifold B. Exhaust manifold A is connected to the intake port A of the second flow channel, and exhaust manifold B is connected to the intake port B of the first flow channel.

4. The segmented work-operated asymmetric dual-channel vortex shell as described in claim 3, characterized in that: definition The section perpendicular to the central axis of the turbine cavity is the cross section. The cross section profiles of the first and second flow channels are involute curved surfaces, and the dimensional accuracy of the flow channel profiles is ≤ ±0.2mm.

5. The segmented, work-operated, asymmetric dual-channel vortex shell as described in claim 4, characterized in that: The isolation wall between the first and second flow channels is integrally cast with the vortex shell.

6. The segmented, work-operated, asymmetric dual-channel vortex shell as described in claim 4, characterized in that: A1:A2 = 0.8:

1.

7. A method for controlling the segmented power output of a vortex-shell dual-channel flow case, based on the segmented power output asymmetric dual-channel vortex-shell as described in claim 6, characterized in that: This includes low-speed operating condition control methods, high-speed operating condition control methods, and transitional operating condition control methods; The low-speed operating condition control method is as follows: The exhaust mass flow rate of the engine is relatively small. The exhaust gas of cylinders 1 and 4 enters the first flow channel and does work in the first circumferential area of ​​the rear section, driving the turbine to rotate. The exhaust gas of cylinders 2 and 3 enters the second flow channel. However, at this time, the high pulse energy of the first flow channel dominates the turbine to start rotating, the response is fast, the lag is reduced, and it is suitable for low-speed operating conditions. The high-speed operating condition control method is as follows: The engine exhaust mass flow rate is relatively large. The exhaust gas of cylinders 1 and 4 enters the first flow channel and does work in the first circumferential area of ​​the rear section. The exhaust gas of cylinders 2 and 3 enters the second flow channel and does work in the second circumferential area of ​​the rear section. Together they drive the turbine to rotate, meet the turbine speed requirements, and avoid the waste of energy caused by exhaust gas bypass. The transition condition control method is as follows: the first circumferential region and the second circumferential region together form a complete circumferential angle, so that the two power-operating regions are seamlessly connected, the turbine speed transitions smoothly, and there is no power interruption or impact.

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