CN115292934A - Design method for eccentric intersection of bypass branch and main pipe of two-stage turbocharging system - Google Patents
Design method for eccentric intersection of bypass branch and main pipe of two-stage turbocharging system Download PDFInfo
- Publication number
- CN115292934A CN115292934A CN202210943104.0A CN202210943104A CN115292934A CN 115292934 A CN115292934 A CN 115292934A CN 202210943104 A CN202210943104 A CN 202210943104A CN 115292934 A CN115292934 A CN 115292934A
- Authority
- CN
- China
- Prior art keywords
- turbine
- low
- main pipe
- pressure
- bypass branch
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 238000013461 design Methods 0.000 title claims abstract description 27
- 238000000034 method Methods 0.000 title claims abstract description 14
- 238000004364 calculation method Methods 0.000 claims abstract description 11
- 230000003068 static effect Effects 0.000 claims description 7
- 238000004088 simulation Methods 0.000 claims description 3
- 238000010586 diagram Methods 0.000 description 3
- 230000000694 effects Effects 0.000 description 2
- 239000012530 fluid Substances 0.000 description 2
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 230000001808 coupling effect Effects 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 238000004134 energy conservation Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000002708 enhancing effect Effects 0.000 description 1
- 230000002401 inhibitory effect Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000011160 research Methods 0.000 description 1
Images
Classifications
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F30/00—Computer-aided design [CAD]
- G06F30/20—Design optimisation, verification or simulation
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
- F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
- F02B37/00—Engines characterised by provision of pumps driven at least for part of the time by exhaust
- F02B37/12—Control of the pumps
- F02B37/18—Control of the pumps by bypassing exhaust from the inlet to the outlet of turbine or to the atmosphere
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F2119/00—Details relating to the type or aim of the analysis or the optimisation
- G06F2119/08—Thermal analysis or thermal optimisation
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
- Y02T10/00—Road transport of goods or passengers
- Y02T10/10—Internal combustion engine [ICE] based vehicles
- Y02T10/12—Improving ICE efficiencies
Abstract
A design method for eccentric intersection of a bypass branch and a main pipe of a two-stage turbocharging system in the technical field of turbocharging comprises the following steps: communicating an air inlet of a high-pressure stage turbine with an engine exhaust manifold, and connecting an air outlet of the high-pressure stage turbine with an air inlet of a low-pressure turbine; communicating an air inlet of a bypass branch pipe with an engine exhaust main pipe, communicating an air outlet of the bypass branch pipe with an interstage main pipe in front of a low-pressure machine turbine, and arranging a bypass valve on the bypass branch pipe; respectively designing the joints of the bypass branch pipes and the interstage main pipe in a left-biased, unbiased and right-biased mode; the influence of left deviation, right deviation and unbiased left deviation on the efficiency of the low-pressure turbine is respectively measured through an isentropic efficiency calculation formula of the low-pressure turbine, and a finally adopted design scheme is determined. The method is simple and effective, has wide application, can perform offset design of the bypass branch pipe on different adjustable two-stage turbocharging systems and even multi-stage turbocharging systems, and achieves the purpose of improving the efficiency of the low-pressure stage turbine.
Description
Technical Field
The invention relates to a design method in the technical field of turbocharging, in particular to a design method for eccentric intersection of a bypass branch and a main pipe of a two-stage turbocharging system, which can improve the efficiency of a low-pressure stage turbine.
Background
With stricter emission regulations and further deepening of energy-saving and emission-reducing concepts, the engine is continuously developed towards the directions of high efficiency, energy conservation, cleanness and low carbon. The two superchargers are connected through the elbow and the bypass valve with adjustable opening degree to realize the optimal distribution of load, and the two superchargers have the advantages of high supercharge, wide flow range, strong regulation capacity, high efficiency and the like, and become an advanced turbocharging technology widely applied to a new generation of power devices.
The adjustable two-stage supercharging system is influenced by miniaturization of an engine, the adjustable two-stage supercharging system has high structural compactness, complex pipeline structures such as highly-twisted and violently-steering elbows and bypass branches are arranged between two turbines, and internal flow of the whole pipeline system is more complex compared with that of the traditional single-stage turbocharging. Due to the structural characteristics, the interstage pipelines of the two-stage supercharging system and the inlets and outlets of the high-pressure stage turbine and the low-pressure stage turbine have different forms of flow distortion, so that the flow inside the pipelines is more complicated. Complications in the flow field can cause changes in turbine air performance, further affecting the performance of the turbocharger system and thus the entire engine. Research shows that coupling effect exists between two stages of turbines in a two-stage adjustable supercharging system to a certain degree, one of the expression forms is that the outlet rotational flow of a high-pressure stage turbine influences the performance of a low-pressure stage turbine, and compared with the inlet condition of a steady-state uniform direct-current turbine, the outlet speed field rotational flow effect of the high-pressure stage turbine influences the efficiency of the low-pressure stage turbine by about 2% -3%.
Disclosure of Invention
Aiming at the defects of the prior art, the invention provides a design method for eccentric intersection of a bypass branch pipe and a main pipe of an adjustable two-stage turbocharging system, when a bypass valve is in a full-open state, the deflection position of a bypass pipeline on an interstage main pipe is adjusted according to high-pressure stage outlet rotational flows with different turning directions, the flowing form of airflow at a low-pressure stage turbine inlet pipeline is changed, the effect of enhancing or inhibiting the rotational flows is achieved, and therefore the pneumatic efficiency of a low-pressure stage turbine is changed.
The invention is realized by the following technical scheme: the invention comprises the following steps:
the method comprises the following steps that firstly, the air inlet of a high-pressure stage turbine is communicated with an engine exhaust main pipe, and the air outlet of the high-pressure stage turbine is connected with the air inlet of a low-pressure turbine through an interstage main pipe;
communicating an air inlet of a bypass branch pipe with an engine exhaust main pipe, communicating an air outlet of the bypass branch pipe with an interstage main pipe in front of a low-pressure machine turbine, and arranging a bypass valve on the bypass branch pipe;
respectively carrying out left deviation design, unbiased design and right deviation design on the joint of the bypass branch pipe and the interstage main pipe, and respectively carrying out simulation calculation on the three designs under the condition that the bypass valve is fully opened;
and step four, respectively measuring the influence of left deviation, right deviation and unbiased left deviation on the efficiency of the low-pressure turbine through an isentropic efficiency calculation formula of the low-pressure turbine, and determining a finally adopted design scheme.
Further, in the invention, the isentropic efficiency calculation formula of the low-pressure stage turbine is as follows:
in the formula, T t-in Is the turbine inlet total temperature in K; t is s-out The turbine outlet static temperature is expressed in K; p t-in Is total pressure at the inlet of the turbine in Pa; p is s-out Is turbine outlet static pressure, in Pa; gamma is a dimensionless air adiabatic coefficient, and the value is 1.353.
The invention mainly comprises an interstage main pipe, a bypass branch and a low-pressure stage turbine, wherein the interstage main pipe is a main flow pipeline between the high-pressure stage turbine and the low-pressure stage turbine, and the bypass valve is equivalent to a bypass branch pipe for directly introducing airflow from an exhaust main pipe to an inlet pipeline of the low-pressure stage turbine. The bypass valve is divided into a full-open state and a full-closed state, and the flowing state and the distribution form of airflow in the pipeline are changed by opening and closing the valve, so that the pneumatic performance of the low-pressure stage turbine is changed. When the bypass valve is fully closed, the airflow of the exhaust main pipe flows into the high-pressure stage turbine, the interstage main pipe and the low-pressure stage turbine in sequence. At the moment, the outlet rotational flow of the high-pressure stage turbine directly enters the low-pressure stage turbine after further development in the interstage main pipe; when the bypass valve is fully opened, one branch of the exhaust main pipe directly flows into the bypass branch pipe and is merged with the high-pressure stage outlet in the intersection point of the bypass branch pipe and the interstage main pipe in a swirling mode, and the two airflows are mixed and acted with each other to form a low-pressure stage turbine inlet flow form completely different from that when the valve is closed. The aerodynamic efficiency of a turbine as a high-speed rotating fluid machine is greatly influenced by the internal fluid flow state, and the change of the turbine inlet flow state tends to cause the change of the turbine efficiency. The influence caused by the eccentricity of the bypass branch pipe is measured by the isentropic efficiency change of the low-pressure stage turbine.
Compared with the prior art, the invention has the following beneficial effects: the method is simple and effective, has wide application, can carry out the offset design of the bypass branch pipe on different adjustable two-stage turbocharging systems and even multi-stage turbocharging systems, and achieves the aim of improving the efficiency of the low-pressure stage turbocharging system.
Drawings
FIG. 1 is a schematic view of a bypass branch in an embodiment of the present invention;
FIG. 2 is a schematic view of an embodiment of the invention showing an unbiased bypass branch;
FIG. 3 is a schematic diagram of a left offset of the bypass branch pipe according to the embodiment of the present invention;
FIG. 4 is a schematic diagram of a right-hand offset bypass branch according to an embodiment of the present invention;
FIG. 5 is a schematic diagram of the low-pressure stage turbine efficiency variation under different eccentricity modes in the embodiment of the invention.
Wherein, 1 is an interstage main pipe, 2 is a bypass branch pipe, and 3 is a low-pressure stage turbine.
Detailed Description
The following describes embodiments of the present invention in detail with reference to the accompanying drawings, and the embodiments of the present invention are based on the technical scheme of the present invention and provide detailed implementation and specific operation procedures, but the scope of the present invention is not limited to the following embodiments.
Examples
As shown in fig. 1 to 5, an air inlet of a high-pressure stage turbine is communicated with an engine exhaust manifold, and an air outlet of the high-pressure stage turbine is connected with an air inlet of a low-pressure turbine 3 through an interstage main pipe 1; communicating an air inlet of a bypass branch pipe 2 with an engine exhaust main pipe, communicating an air outlet of the bypass branch pipe 2 with an interstage main pipe 1 in front of a low-pressure machine turbine, and arranging a bypass valve on the bypass branch pipe 2; respectively carrying out left deviation design, right deviation design and unbiased design on the joint of the bypass branch pipe and the interstage main pipe, and respectively carrying out simulation calculation on the three designs under the condition that the bypass valve is fully opened; the influence of left deviation, right deviation and unbiased left deviation on the efficiency of the low-pressure turbine is respectively measured through an isentropic efficiency calculation formula of the low-pressure turbine, and a finally adopted design scheme is determined.
The isentropic efficiency calculation formula of the low-pressure stage turbine is as follows:
in the formula, T t-in Is the total temperature at the turbine inlet, in units of K; t is s-out The turbine outlet static temperature is in K; p t-in Is total pressure at the inlet of the turbine in Pa; p s-out Is turbine outlet static pressure, in Pa; gamma is a dimensionless air adiabatic coefficient, and the value is 1.353.
In the embodiment, given that the total inlet temperature of the high-pressure stage turbine is 873.15K, the total inlet pressure of the high-pressure stage turbine is 200Kpa, the static outlet pressure of the low-pressure stage turbine is 101Kpa, and three-dimensional numerical calculation based on Ansys-CFX is carried out, wherein the rotating speed of the high-pressure stage turbine is 41800rpm, and the rotating speed of the low-pressure stage turbine is 52100rpm. Based on this, the bypass line shown in fig. 1 is adjusted in the offset position of the bypass valve with respect to the interstage main pipe 1, as shown in fig. 2 (left offset of the bypass valve), fig. 3 (non-offset of the bypass valve), and fig. 4 (right offset of the bypass valve). The bypass branch 2 airflow under different bypass valve bias modes causes different distortions of the high-pressure stage outlet rotational flow, namely, the low-pressure stage turbine 3 inlet airflow is different, finally the low-pressure stage turbine isentropic efficiency calculated according to the low-pressure stage turbine isentropic efficiency calculation formula is shown in fig. 5, and the ordinate in fig. 5 is the low-pressure stage turbine isentropic efficiency. As can be seen in fig. 5, the left offset of the bypass valve reduces the low pressure stage turbine efficiency by about 2.5% and the right offset of the bypass valve improves the low pressure stage turbine efficiency by about 2.2% relative to the case where the bypass valve is not offset.
The specific mode of operation of the present invention has been described. It is to be understood that the present invention is not limited to the specific operating modes described above, and that various changes or modifications may be made by one skilled in the art within the scope of the appended claims without departing from the spirit of the invention.
Claims (3)
1. A design method for eccentric intersection of a bypass branch and a main pipe of a two-stage turbocharging system is characterized by comprising the following steps: the flow shape of the airflow at the inlet pipeline of the low-pressure stage turbine is changed by changing the deflection position of the bypass branch pipe on the interstage main pipe, so that the aerodynamic efficiency of the low-pressure stage turbine is changed.
2. The design method for the eccentric intersection of the bypass branch and the main pipe of the two-stage turbocharging system according to claim 1, characterized by comprising the following steps:
the method comprises the following steps that firstly, an air inlet of a high-pressure stage turbine is communicated with an engine exhaust main pipe, and an air outlet of the high-pressure stage turbine is connected with an air inlet of a low-pressure turbine through an inter-stage main pipe;
communicating an air inlet of a bypass branch pipe with an engine exhaust main pipe, communicating an air outlet of the bypass branch pipe with an interstage main pipe in front of a low-pressure machine turbine, and arranging a bypass valve on the bypass branch pipe;
respectively carrying out left deviation design, unbiased design and right deviation design on the joint of the bypass branch pipe and the interstage main pipe, and respectively carrying out simulation calculation on the three designs under the condition that the bypass valve is fully opened;
and step four, respectively measuring the influence of left deviation, right deviation and unbiased left deviation on the efficiency of the low-pressure turbine through an isentropic efficiency calculation formula of the low-pressure turbine, and determining a finally adopted design scheme.
3. The design method for the eccentric intersection of the bypass branch and the main pipe of the two-stage turbocharging system according to claim 1, wherein the isentropic efficiency of the low-pressure stage turbine is calculated by the formula:
in the formula, T t-in Is the turbine inlet total temperature in K; t is s-out The turbine outlet static temperature is in K; p t-in Is total pressure at the inlet of the turbine in Pa; p s-out Is turbine outlet static pressure, in Pa; gamma is a dimensionless air adiabatic coefficient, and the value is 1.353.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210943104.0A CN115292934B (en) | 2022-08-08 | 2022-08-08 | Design method for eccentric intersecting of bypass branch and main pipe of two-stage turbocharging system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210943104.0A CN115292934B (en) | 2022-08-08 | 2022-08-08 | Design method for eccentric intersecting of bypass branch and main pipe of two-stage turbocharging system |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN115292934A true CN115292934A (en) | 2022-11-04 |
| CN115292934B CN115292934B (en) | 2024-01-26 |
Family
ID=83827602
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210943104.0A Active CN115292934B (en) | 2022-08-08 | 2022-08-08 | Design method for eccentric intersecting of bypass branch and main pipe of two-stage turbocharging system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115292934B (en) |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2007154684A (en) * | 2005-12-01 | 2007-06-21 | Isuzu Motors Ltd | Two-stage supercharging type engine |
| CN103615309A (en) * | 2013-12-10 | 2014-03-05 | 吉林大学 | All-work-condition adjustable two-stage pressurizing system of internal combustion engine |
| CN105386857A (en) * | 2015-11-27 | 2016-03-09 | 吉林大学 | Internal combustion engine two-stage pressurization control system and control method thereof |
| US20180038290A1 (en) * | 2015-03-30 | 2018-02-08 | Mitsubishi Heavy Industries, Ltd. | Turbine supercharger and two-stage supercharging system |
| CN108931379A (en) * | 2018-05-24 | 2018-12-04 | 北京理工大学 | A kind of turbine efficiency measurement method |
| CN113503262A (en) * | 2021-08-11 | 2021-10-15 | 北京理工大学 | Simulation method for high-low pressure turbine of two-stage supercharging system |
-
2022
- 2022-08-08 CN CN202210943104.0A patent/CN115292934B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2007154684A (en) * | 2005-12-01 | 2007-06-21 | Isuzu Motors Ltd | Two-stage supercharging type engine |
| CN103615309A (en) * | 2013-12-10 | 2014-03-05 | 吉林大学 | All-work-condition adjustable two-stage pressurizing system of internal combustion engine |
| US20180038290A1 (en) * | 2015-03-30 | 2018-02-08 | Mitsubishi Heavy Industries, Ltd. | Turbine supercharger and two-stage supercharging system |
| CN105386857A (en) * | 2015-11-27 | 2016-03-09 | 吉林大学 | Internal combustion engine two-stage pressurization control system and control method thereof |
| CN108931379A (en) * | 2018-05-24 | 2018-12-04 | 北京理工大学 | A kind of turbine efficiency measurement method |
| CN113503262A (en) * | 2021-08-11 | 2021-10-15 | 北京理工大学 | Simulation method for high-low pressure turbine of two-stage supercharging system |
Non-Patent Citations (1)
| Title |
|---|
| 张来涛;徐岩;刘胜;利奇;石磊;邓康耀;杨震寰;: "柴油机可调两级增压系统变海拔稳态调节特性研究", 车用发动机, no. 05, pages 31 - 36 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN115292934B (en) | 2024-01-26 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN201513258U (en) | Hybrid exhaust gas recirculation multi-loop device of series two-stage supercharged engine | |
| JP4448853B2 (en) | Turbocharger system for an internal combustion engine consisting of a radial type compressor stage with a compressor wheel with swept blades | |
| KR940001922B1 (en) | Internal combustion engine having a supercharging operation using a group of switchable exhaust gas turbochargers | |
| JP2005098250A (en) | Turbocharging device | |
| US20180142610A1 (en) | Improved device for controlling the amount of air fed into the intake of a supercharged internal combustion engine and method using such a device | |
| CN114060143B (en) | Variable-altitude boost pressure stability control method based on bypass valve flow characteristic | |
| CN112253515A (en) | State adjusting method for performance test of double-duct combined type gas compressor | |
| CN106468208A (en) | Turbocharger with the compressor that may operate at single mode or two-stage series connection pattern | |
| CN102434268A (en) | Double-turbine double-air-compressor turbocharging system | |
| CN102818706A (en) | Simulating test method for plateau performance of supercharged engine and device for implementing simulating test method | |
| CN201513259U (en) | Exhaust gas recirculation multi-loop device of series two-stage supercharged engine | |
| CN111076941A (en) | double-VGT two-stage adjustable supercharger test system | |
| CN112524080A (en) | Adjustable two-stage turbocharging system test platform | |
| CN102400777B (en) | Single-vortex double-air compressor turbine pressurizing system with air escape valves | |
| CN115292934B (en) | Design method for eccentric intersecting of bypass branch and main pipe of two-stage turbocharging system | |
| CN102418593B (en) | Single-vortex double-pressure turbocharging system | |
| CN204253169U (en) | A kind of two independent turbine variable boost device | |
| CN106870214B (en) | Double-runner turbocharger | |
| CN102400778A (en) | Serial-parallel adjustable single-vortex double-pressure turbocharging system | |
| CN102444464A (en) | Twin-turbine single-voltage turbine supercharging system | |
| CN104481673A (en) | Exhaust gas turbocharger volute bypass device | |
| CN212027927U (en) | Two-stage turbocharging system with controllable connection mode | |
| CN111946444A (en) | Three-stage variable-section turbine two-stage sequential supercharging system and control method | |
| CN215409358U (en) | Adjustable two-stage turbocharging system test platform | |
| JPH0223229A (en) | Twin-type exhaust turbocharger |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |