A gas engine EGR rate boosting air extraction device

Abstract

The utility model discloses a kind of exhaust device of promoting gas engine EGR rate, including air inlet connector, air outlet connector, Mercedes ring, micro brushless DC motor and fan, the air inlet connector is connected with air outlet connector, Mercedes ring, micro brushless DC motor, fan is located inside the cavity formed by air inlet connector and air outlet connector. Mercedes ring is installed in the inside of air inlet connector and air outlet connector, the rotating shaft end of micro brushless DC motor is connected with fan after passing through Mercedes ring. A kind of exhaust device of promoting gas engine EGR rate provided by the utility model, can promote fuel economy, by improving EGR rate, support engine to adopt higher compression ratio and advanced combustion strategy, improve thermal efficiency and reduce fuel consumption rate.

Description

Technical Field

[0001] This utility model belongs to the field of internal combustion engine and energy conservation and emission reduction technology, specifically relating to an air extraction device for improving the EGR rate of a gas engine. Background Technology

[0002] EGR technology reintroduces a portion of the engine exhaust gas into the combustion chamber for combustion, utilizing the inert components in the exhaust gas to alter the combustion environment, creating a dilution and cooling effect, delaying combustion, and inhibiting the formation of nitrogen oxides (NOx) at the source.

[0003] The application of existing EGR technology in gas turbine engines faces challenges. This is due to the intertwining of three core issues: the difficulty in adjusting the EGR rate, the high requirements for mixing uniformity, and the difficulty in adapting to a wide range of operating conditions, with the combustion characteristics of gas turbine engines and the boundaries of lean-burn technology. These factors form a complex coupling relationship, which not only hinders the efficient reduction of NOx emissions under all operating conditions, but also has a systemic negative impact on the engine's power and economy.

[0004] As the core component of traditional EGR systems for mixing exhaust gas and fresh air, the Venturi mixer's design is heavily reliant on the "optimal economic speed range," making its physical structure a rigid bottleneck restricting the EGR system's adaptability to a wide range of operating conditions. When the engine speed deviates from this range, the balance between airflow parameters and the mixer structure is disrupted. The nonlinear decay of negative pressure and mixing efficiency directly leads to a comprehensive deterioration in system performance, ultimately resulting in the technical dilemma of "stable emission reduction under all operating conditions."

[0005] There is a significant reinforcing relationship between EGR rate imbalance and uncontrolled mixing uniformity. Traditional EGR systems rely on the pressure difference between exhaust and intake gases to drive exhaust gas recirculation. Under low-speed, low-load conditions, insufficient pressure difference leads to a sharp drop in EGR rate. Simultaneously, the negative pressure of the mixer decreases, and mixing efficiency declines, requiring the engine to enrich the mixture to maintain combustion stability. The high-oxygen environment created by lean-burn technology further exacerbates the excessively lean exhaust gas in some areas, creating ideal conditions for NOx formation: high temperature + oxygen enrichment. More seriously, there is a deviation in EGR rate among cylinders. Some cylinders suffer from excessive oxygen deficiency, leading to misfire, while others continue to burn at high temperatures due to insufficient EGR, resulting in the dual problems of excessive emissions and power fluctuations.

[0006] The difficulty in adapting to a wide range of operating conditions further amplifies the negative impacts of the previous two factors. Excessive pressure differences under high-speed, high-load conditions lead to a sharp increase in the EGR rate. Overly diluted gas mixtures cause a sudden drop in flame propagation speed, potentially even triggering misfires, and unburned gases remain in the high-temperature zone for an extended period. Simultaneously, the turbulent flow field generated by high-speed airflow causes uncontrolled mixing and a sharp decrease in uniformity. Localized "high-inertia zones" prolong reaction time due to slow combustion, leading to continuous NOx generation at high temperatures, while "low-inertia zones," with excessively high oxygen concentrations and ineffective temperature control, become local sources of NOx generation. Under transient conditions, this non-uniformity reaches its peak: sudden changes in engine speed cause drastic fluctuations in the EGR rate and simultaneous deterioration in mixing uniformity, resulting in NOx emission fluctuations exceeding acceptable ranges for engineering applications and causing a momentary drop in power output.

[0007] Existing EGR systems suffer from problems such as difficulty in adjusting the EGR rate, high requirements for mixing uniformity, and poor adaptability to a wide range of operating conditions. Utility Model Content

[0008] The purpose of this invention is to solve the above-mentioned problems and provide an extraction device that achieves stable and efficient NOx emission reduction, realizes the synergistic optimization of the EGR system for emissions, power performance and economy, significantly improves the wide operating condition adaptability of gas engines, and improves the EGR rate of gas engines.

[0009] To solve the above-mentioned technical problems, the technical solution of this utility model is: an air extraction device for improving the EGR rate of a gas engine, comprising an intake connector, an outlet connector, a Mercedes-Benz ring, a miniature brushless DC motor, and a fan. The intake connector is connected to the outlet connector, and the Mercedes-Benz ring, the miniature brushless DC motor, and the fan are located inside the cavity formed by the intake connector and the outlet connector. The Mercedes-Benz ring is installed inside the intake connector and the outlet connector, and the shaft end of the miniature brushless DC motor passes through the Mercedes-Benz ring and is connected to the fan.

[0010] Preferably, the air inlet connector is a hollow structure with openings at both ends, and an air inlet channel is provided inside the air inlet connector for receiving exhaust gas.

[0011] Preferably, the air outlet connector is a hollow structure with openings at both ends, and an air outlet channel is provided inside the air outlet connector.

[0012] Preferably, the Mercedes ring includes an outer ring, an inner ring, and a retainer. The outer ring is fixedly connected to the inner ring through the retainer. The outer ring is divided into three flow distribution zones by the retainer. The inner ring is connected to a miniature brushless DC motor. The outer ring is fixed between the air inlet connector and the air outlet connector.

[0013] Preferably, the miniature brushless DC motor is fixed on the side of the Mercedes ring near the air outlet connector, and its speed is adjusted according to the input power to provide rotational power for the fan blades.

[0014] Preferably, the fan includes a guide cone and blades. The blades are fixedly connected to the outer surface of the guide cone, and adjacent blades form a fan flow channel. The guide cone is connected to the shaft end of a miniature brushless DC motor. When the blades rotate, the compressed airflow in the fan flow channel flows outward into the airflow channel. The beneficial effects of this invention are:

[0015] 1. The present invention provides an air extraction device for improving the EGR rate of a gas engine, which can improve fuel economy. By increasing the EGR rate, the engine can adopt a higher compression ratio and advanced combustion strategy, thereby improving thermal efficiency and reducing fuel consumption.

[0016] 2. This utility model can enhance emission compliance. By increasing the EGR rate, the amount of exhaust gas recirculation can be increased. By reducing the combustion temperature and oxygen concentration, NOx emissions can be significantly reduced. At the same time, carbon dioxide emissions can be reduced by improving thermal efficiency. Under low load conditions, CO and unburned hydrocarbon emissions can be reduced, meeting stringent emission standards such as China VI and Euro VI.

[0017] 3. This utility model reduces maintenance costs by optimizing the combustion process, reducing engine wear and maintenance needs, alleviating the burden on the aftertreatment system, and lowering the maintenance costs of the aftertreatment system.

[0018] 4. This utility model can extend engine life by reducing combustion temperature and heat load, thereby reducing the frequency of overhauls and the total cost of ownership.

[0019] 5. This utility model can achieve stable and efficient NOx emission reduction across the entire speed range, and achieve synergistic optimization of emissions, power and economy by the EGR system, significantly improving the wide operating condition adaptability of the gas engine. Attached Figure Description

[0020] Figure 1 This is a structural diagram of an extraction device for improving the EGR rate of a gas engine according to the present invention.

[0021] Figure 2 This is a schematic diagram of the exploded structure of this utility model;

[0022] Figure 3 This is a utility model Figure 1 Structure diagram in direction A;

[0023] Figure 4 This is a utility model Figure 1 A structural diagram observed from direction B;

[0024] Figure 5 This is a utility model Figure 1 Structural diagram viewed from the C-direction;

[0025] Figure 6This is a utility model Figure 5 A cross-sectional view of the structure as observed from the DD direction;

[0026] Figure 7 This is a three-dimensional structural diagram of the fan blade of this utility model;

[0027] Figure 8 This is a three-dimensional structural diagram of the Mercedes-Benz ring of this utility model;

[0028] Figure 9 This is a structural diagram of the application scenario of this utility model;

[0029] Figure 10 This is a utility model Figure 9 A partial cross-sectional view of the structure along the E direction.

[0030] Explanation of reference numerals in the attached diagram: 1. Inlet connector; 2. Outlet connector; 3. Mercedes ring; 4. Miniature brushless DC motor; 5. Fan; 11. Inlet air passage; 31. Outer ring; 32. Flow divider; 33. Inner ring; 34. Cage; 51. Drain cone; 52. Fan flow passage; 53. Blade. Detailed Implementation

[0031] The present invention will be further described below with reference to the accompanying drawings and specific embodiments:

[0032] like Figures 1 to 10 As shown, this utility model provides an air extraction device for improving the EGR rate of a gas turbine engine, including an intake connector 1, an outlet connector 2, a Mercedes-Benz ring 3, a miniature brushless DC motor 4, and a fan 5. The intake connector 1 is connected to the outlet connector 2, and the Mercedes-Benz ring 3, the miniature brushless DC motor 4, and the fan 5 are located inside the cavity formed by the intake connector 1 and the outlet connector 2. The Mercedes-Benz ring 3 is installed inside the intake connector 1 and the outlet connector 2, and the shaft end of the miniature brushless DC motor 4 passes through the Mercedes-Benz ring 3 and is connected to the fan 5.

[0033] The air inlet connector 1 is a hollow structure with openings at both ends. An air intake channel 11 is provided inside the air inlet connector 1 to receive exhaust gas. One end of the air inlet connector 1 is connected to existing external equipment, and its end is a rotating structure. The other end of the air inlet connector 1 is connected to the air outlet connector 2. The cross-section of the end of the air inlet connector 1 connected to the air outlet connector 2 is trapezoidal.

[0034] In use, the inlet connector 1 connects to the outlet pipe of an existing EGR cooler or Venturi sensor, and its internal inlet air passage 11 is used to receive the exhaust gas cooled by the outlet of the EGR cooler. The interface size of the inlet connector 1 matches the connecting pipe, which can reduce airflow resistance and ensure smooth exhaust gas entry.

[0035] The exhaust connector 2 is a hollow structure with openings at both ends, and an exhaust channel 21 is provided inside the exhaust connector 2. The end of the exhaust connector 2 is connected to the pipeline at the inlet of the existing EGR valve, and the exhaust gas treated by the extraction device is delivered to the EGR valve through the exhaust channel 21. Similarly, the interface design ensures smooth exhaust gas output and avoids pressure loss due to unreasonable interface shape.

[0036] The Mercedes ring 3 includes an outer ring 31, an inner ring 33, and a retainer 34. The outer ring 31 is fixedly connected to the inner ring 33 through the retainer 34. The interior of the outer ring 31 is divided into three flow distribution zones 32 by the retainer 34. The inner ring 33 is connected to a micro brushless DC motor 4. The outer ring 31 is fixed between the air inlet connector 1 and the air outlet connector 2.

[0037] In this embodiment, the Mercedes ring 3 is located between the air inlet connector 1 and the air outlet connector 2, serving both structural support and airflow optimization functions.

[0038] The inlet air passage 11 is recessed at the connection point with the outlet air passage 21, forming an annular flow channel groove. The outer ring 31 is press-fitted into the flow channel groove formed by the inlet air passage 11 and the outlet air passage 21. The Mercedes ring 3 is divided into three fan-shaped flow distribution zones 32 by three retainers 34.

[0039] The inner ring 33 has three evenly distributed connection holes. Screws pass through the connection holes and are fixed to the miniature brushless DC motor 4, thereby optimizing the overall structure to reduce airflow disturbance through flow field optimization.

[0040] The miniature brushless DC motor 4 is fixed on the side of the Mercedes ring 3 near the air outlet 2. The speed is adjusted according to the input power to provide rotational power for the fan blades.

[0041] In this embodiment, the miniature brushless DC motor 4 is a high-performance miniature brushless DC motor, characterized by fast response speed, wide speed range, high efficiency, and long lifespan, capable of quickly adapting to the speed requirements of different operating conditions. In this embodiment, the miniature brushless DC motor 4 adopts the existing miniature brushless DC motor R-2838.

[0042] The fan 5 includes a flow cone 51 and blades 53. The blades 53 are fixed to the outer surface of the flow cone 51. Adjacent blades 53 form a fan flow channel 52. The flow cone 51 is connected to the shaft end of the micro brushless DC motor 4. When the blades 53 rotate, the airflow in the compressed fan flow channel 52 flows to the outlet airflow channel 21.

[0043] In this embodiment, the guide cone 51 is mounted on the motor shaft of the miniature brushless DC motor 4 on the side of the Mercedes ring 3 near the intake connector 1, located within the intake air passage 11. The shape, angle, and number of blades 53 have been optimized through fluid dynamics simulation to minimize airflow resistance and noise caused by their own rotation while ensuring suction effect. The guide cone 51 guides the exhaust airflow of the intake air passage 11 towards the fan passage 52, and the blades 53 divide the intake air passage 11 into multiple fan passages 52.

[0044] The core of this invention's improved EGR rate lies in the coordinated operation of its extraction device with existing EGR systems. It achieves efficient waste gas recirculation through a combined driving mechanism of "pressure difference and active suction." The specific workflow of this invention in actual operation is as follows:

[0045] like Figure 9 and Figure 10 As shown, one end of this utility model is connected to an existing one-way valve seat A, and the other end is connected to an existing exhaust gas inlet B. The exhaust gas inlet B is connected to an existing EGR valve C and an existing mixer D. The mixer D has a four-way pipe structure, and the other three ports of the mixer D are marked with "F", "G", and "H" respectively. In the one-way valve seat A, the air inlet is "E". The arrows represented by "E", "F", "G", and "H" indicate the direction of the corresponding airflow. Among them, exhaust gas is introduced from the direction indicated by "E", and the exhaust gas is generated by the existing engine exhaust. "F" indicates that fresh air enters the mixer D through the existing turbocharger. The EGR valve C is used to control the amount of exhaust gas entering the mixer D. "G" indicates the direction of combustion gas entering the mixer D. The combustion gas includes liquefied natural gas, compressed natural gas, and similar combustible gases. "H" indicates the direction of movement of the mixed gas. The mixed gas is used for combustion in the engine. The mixer D uniformly mixes the incoming air, combustion gas, and exhaust gas for subsequent use. Exhaust gas enters the extraction device through the existing intake pipe. Under conventional pressure difference-driven conditions, the exhaust gas flows in naturally. When the pressure difference is insufficient, the input power of the micro brushless DC motor 4 is adjusted to drive the blades 53 of the fan 5 to rotate, generating active suction and forcibly drawing in the exhaust gas. After being delivered to the existing EGR valve through the outlet connector 2, it is fully mixed with fresh air and fuel gas in the mixer D, and finally enters the existing combustion chamber to participate in combustion.

[0046] The following adjustments are made to this invention under different working conditions:

[0047] Low-speed, low-load conditions: When the pressure difference is insufficient, the power of the micro brushless DC motor 4 is increased, and the blades 53 rotate at high speed to generate additional negative pressure, which makes up for the insufficient pressure difference, offsets the negative pressure attenuation of the mixer, and increases the EGR rate to suppress NOx emissions.

[0048] High-speed, high-load operating conditions: When the pressure difference is too large, reduce the power of the micro brushless DC motor 4 or shut it down, and limit the exhaust gas volume only by the existing EGR valve opening to avoid the impact of EGR rate fluctuations on power and economy.

[0049] Transient operating conditions: The sensor provides real-time feedback on changes in operating conditions, and the ECU quickly adjusts the power of the micro brushless DC motor 4 and the opening of the EGR valve C. The pressure difference is dynamically adjusted through the air extraction device to maintain a stable EGR rate, ensuring stable combustion and compliance with emission standards, thus eliminating the passive dependence on pressure difference.

[0050] The technical solution of this invention is to add an EGR extraction device to the EGR pipeline before the EGR valve. By actively extracting exhaust gas, it breaks through the dependence on the Venturi effect and pressure difference, shifting from "passive dependence" to "active controllability," achieving active control over exhaust gas flow and significantly improving the EGR rate. This invention can significantly reduce NOx emissions by reintroducing a portion of the exhaust gas into the cylinder. The exhaust gas includes CO2, N2, and water vapor, which do not participate in combustion. CO2 has a high specific heat capacity and can effectively absorb combustion heat, thereby lowering the maximum combustion temperature in the cylinder, while NOx is generated under high-temperature, oxygen-rich conditions. The exhaust gas dilutes the oxygen concentration in the fresh intake air, making the combustion environment more "oxygen-deficient," further inhibiting NOx formation and improving the EGR rate in the low-speed, low-load operating range.

[0051] Those skilled in the art will recognize that the embodiments described herein are intended to help the reader understand the principles of this invention, and should be understood that the scope of protection of this invention is not limited to such specific statements and embodiments. Those skilled in the art can make various other specific modifications and combinations based on these technical teachings disclosed in this invention without departing from the essence of this invention, and these modifications and combinations are still within the scope of protection of this invention.

Claims

1. A gas extraction device for improving the EGR rate of a gas turbine engine, characterized in that: It includes an air inlet connector (1), an air outlet connector (2), a Mercedes ring (3), a miniature brushless DC motor (4), and a fan (5). The air inlet connector (1) is connected to the air outlet connector (2). The Mercedes ring (3), the miniature brushless DC motor (4), and the fan (5) are located inside the cavity formed by the air inlet connector (1) and the air outlet connector (2). The Mercedes ring (3) is installed inside the air inlet connector (1) and the air outlet connector (2). The shaft end of the miniature brushless DC motor (4) passes through the Mercedes ring (3) and is connected to the fan (5).

2. The extraction device for improving the EGR rate of a gas turbine engine according to claim 1, characterized in that: The air inlet connector (1) is a hollow structure with openings at both ends. An air inlet channel (11) is provided inside the air inlet connector (1) for receiving exhaust gas.

3. The extraction device for improving the EGR rate of a gas turbine engine according to claim 1, characterized in that: The air outlet connector (2) is a hollow structure with openings at both ends, and an air outlet channel (21) is provided inside the air outlet connector (2).

4. The extraction device for improving the EGR rate of a gas turbine engine according to claim 1, characterized in that: The Mercedes ring (3) includes an outer ring (31), an inner ring (33) and a retainer (34). The outer ring (31) is fixed to the inner ring (33) through the retainer (34). The interior of the outer ring (31) is divided into three flow distribution zones (32) through the retainer (34). The inner ring (33) is connected to a micro brushless DC motor (4). The outer ring (31) is fixed between the air inlet connector (1) and the air outlet connector (2).

5. The extraction device for improving the EGR rate of a gas turbine engine according to claim 1, characterized in that: The miniature brushless DC motor (4) is fixed on the side of the Mercedes ring (3) near the air outlet (2), and its speed is adjusted according to the input power to provide rotational power for the fan blades.

6. The extraction device for improving the EGR rate of a gas turbine engine according to claim 1, characterized in that: The fan (5) includes a flow cone (51) and blades (53). The blades (53) are fixed to the outer surface of the flow cone (51). Adjacent blades (53) form a fan flow channel (52). The flow cone (51) is connected to the shaft end of the micro brushless DC motor (4). When the blades (53) rotate, the airflow in the compressed fan flow channel (52) flows to the outlet airflow channel (21).

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