A double-oil-path gas-assisted ultra-fine atomizing nozzle and atomizing system suitable for wide load conditions and an injection control method

Abstract

The purpose of this invention is to provide a dual-oil-circuit air-assisted ultra-fine atomizing nozzle and atomization system suitable for a wide range of operating conditions, belonging to the field of engine technology. The housing contains three independent main oil supply lines, a secondary oil supply line, and an auxiliary air supply line. A swirler is installed in the main oil supply line to form a rotating liquid film of fuel in the outlet area; compressed gas introduced through the auxiliary air supply line applies a high-speed shearing action to the fuel liquid film at the nozzle outlet. By adjusting the fuel supply status and ratio of the main and secondary oil lines, and in conjunction with the shearing action of the auxiliary gas, the nozzle achieves stable ultra-fine atomization injection over a wide load range. This invention balances the fine atomization performance under low load conditions with the high-flow injection requirements under high load conditions, offering advantages such as high atomization stability and a wide load adaptability range.

Description

Technical Field

[0001] The present invention relates to an engine, specifically an atomizing device and a fuel injection control method. Background Technology

[0002] In combustion equipment, small gas turbines, engines, and industrial combustion systems, fuel nozzles need to maintain good atomization performance over a wide load range. However, under low-load conditions, due to a significant reduction in fuel flow and injection pressure, the swirling intensity inside the swirling nozzle is insufficient, the fuel film thickness increases, and the film breaking ability decreases, easily leading to increased droplet size, incomplete combustion, and reduced system stability. Existing single-circuit swirling nozzles typically rely on high fuel supply pressure to obtain sufficient swirling intensity, which can meet the high-flow-rate injection requirements under high-load conditions, but struggles to meet fine atomization requirements under low-load conditions. To improve low-load atomization performance, some technologies introduce pneumatic assistance, using airflow to shear the fuel film; however, the single-circuit structure still makes it difficult to flexibly adjust the fuel supply method under different load conditions, resulting in significant variations in atomization performance with different operating conditions. Summary of the Invention

[0003] The purpose of this invention is to provide a dual-oil-path gas-assisted ultrafine atomizing nozzle and atomization system suitable for wide-load operating conditions, as well as a fuel injection control method, which can improve atomization stability and combustion adaptability over a wide load range.

[0004] The objective of this invention is achieved as follows: This invention discloses a dual-oil-path air-assisted ultra-fine atomizing nozzle suitable for wide-load operating conditions, characterized by: a main oil path housing, a secondary oil path housing, and an air path housing. The secondary oil path housing is installed outside the main oil path housing, and the air path housing is installed outside the secondary oil path housing. A main oil path supply pipeline is opened in the main oil path housing, and a secondary oil path supply pipeline is opened in the secondary oil path housing. An auxiliary air supply pipeline is formed between the air path housing and the secondary oil path housing. A cyclone separator is installed in the main oil path supply pipeline. The upper part of the cyclone separator is engaged with a protrusion on the inner wall of the main oil path housing, and a cyclone groove is formed between the lower part of the cyclone separator and the inner wall of the main oil path housing. A cyclone chamber is formed in the main oil path housing below the cyclone groove.

[0005] The present invention may also include: 1. The bottom of the main oil supply line is the nozzle end of the main oil supply line, the bottom of the auxiliary oil supply line is the nozzle end of the auxiliary oil supply line, and the bottom of the auxiliary air supply line is the compressed air outlet. The nozzle ends of the main oil supply line, the nozzle ends of the auxiliary oil supply line, and the compressed air outlet converge at one place.

[0006] 2. The vortex chamber is funnel-shaped.

[0007] This invention discloses an atomization system, characterized by comprising an ECU control unit, an oil tank, a gear pump, an air source, a main oil circuit pressure control valve, a secondary oil circuit pressure control valve, an auxiliary air pressure control valve, and an atomizing nozzle as described in claim 1. The oil tank is connected to the gear pump; the main oil circuit pressure control valve and the secondary oil circuit pressure control valve are connected in parallel to the gear pump; the main oil circuit supply line of the atomizing nozzle is connected to the main oil circuit pressure control valve; the secondary oil circuit supply line of the atomizing nozzle is connected to the secondary oil circuit pressure control valve; the air source is connected to the auxiliary air pressure control valve; the auxiliary air pressure control valve is connected to the auxiliary air supply line of the atomizing nozzle; and the ECU control unit is connected to the main oil circuit pressure control valve, the secondary oil circuit pressure control valve, and the auxiliary air pressure control valve, respectively.

[0008] The atomization system of the present invention may further include: 1. An oil separator is installed between the oil tank and the gear pump.

[0009] The present invention provides a fuel injection control method, characterized in that: the atomization system as described in claim 4 is used to determine the fuel quantity requirement: when the fuel quantity is less than or equal to 150 kg / h, it is determined to be a low-load condition; when the fuel quantity is greater than 150 kg / h and less than 300 kg / h, it is determined to be a medium-load condition; and when the fuel quantity is greater than or equal to 300 kg / h, it is determined to be a high-load condition. Under low load conditions, the main oil circuit is used as the only oil supply mode. The fuel in the main oil circuit forms a rotating liquid film under the action of the swirler and is sprayed out from the nozzle tip of the main oil circuit. The fuel inlet of the auxiliary oil circuit does not supply fuel, but is used to introduce swirling compressed air or auxiliary compressed air, so that the compressed gas is sprayed out from the nozzle tip of the auxiliary oil circuit or the adjacent compressed air outlet, forming a high-speed airflow shear layer on the outside of the fuel liquid film in the main oil circuit. Under medium load conditions, a composite working mode is adopted, which involves main oil circuit fuel supply, auxiliary oil circuit supplementary fuel supply, and simultaneous introduction of compressed air. The fuel in the main oil circuit forms a main rotating liquid film under the action of the cyclone separator, while the fuel in the auxiliary oil circuit participates in the injection as a supplementary flow. Together with the fuel in the main oil circuit, they form a composite liquid film structure in the nozzle outlet area. The compressed air continuously applies a shearing action to the outside of the liquid film, so that the liquid film maintains a stable rupture position and droplet distribution during the breakup process. Under heavy load conditions, the system adopts a working mode of simultaneous fuel supply from the main oil circuit and the auxiliary oil circuit. The system meets the demand for high-flow fuel injection by superimposing fuel from the dual oil circuits: the fuel in the main oil circuit is kept in a rotating state under the action of the cyclone separator, while the fuel in the auxiliary oil circuit participates in the injection on the outside and forms an outer liquid film; compressed air is ejected from the compressed air outlet, which simultaneously applies high-speed shear to the inner and outer fuel liquid films, so that the liquid film can be broken up and droplet co-aggregation can be inhibited under high flow conditions.

[0010] The advantages of this invention are as follows: By combining the synergistic effect of dual-oil-circuit staged fuel supply and compressed air liquid film shearing, this invention effectively solves the problems of insufficient swirl intensity, excessive liquid film thickness, and decreased atomization performance of single-oil-circuit nozzles under low-load conditions. At the same time, it takes into account the high-flow fuel injection requirements under high-load conditions, significantly improving the nozzle's wide-load adaptability and combustion stability. Attached Figure Description

[0011] Figure 1 This is a schematic diagram of the atomizing nozzle of the present invention; Figure 2 This is a schematic diagram of the atomization system of the present invention; Figure 3 This is a flowchart of the present invention. Detailed Implementation

[0012] The invention will now be described in more detail with reference to the accompanying drawings: Combination Figure 1-3 This invention discloses a dual-oil-path air-assisted ultra-fine atomizing nozzle suitable for wide-load operating conditions, comprising an air path housing 4. The air path housing 4 has an overall axisymmetric structure, and its interior is formed by an auxiliary oil path housing 5 and a main oil path housing 6, forming independently arranged main oil path fuel passages and auxiliary oil path fuel passages. Simultaneously, a compressed air passage, independent of the fuel passages, is formed between the air path housing 4 and the auxiliary oil path housing 5. This structural arrangement allows the nozzle to achieve a multi-channel coordinated arrangement within a limited axial space, providing a structural basis for various operating modes under different load conditions.

[0013] The swirler 7 is located within the main fuel passage. After entering the nozzle through the passage defined by the main fuel passage housing 6, the fuel first enters the swirler 7. Its structure allows the fuel to acquire a significant tangential velocity component within a short flow distance, thus forming a stable rotating flow at the swirler groove 9. The fuel then enters the downstream region of the nozzle via the swirler groove 9, forming a rotating liquid film before injection, and is finally ejected from the nozzle tip 10 of the main fuel passage.

[0014] The auxiliary fuel passage is defined by the auxiliary fuel passage housing 5 and is independently set from the main fuel passage. Fuel in the auxiliary fuel passage flows along an independent channel inside the nozzle and is ejected from the nozzle tip 11. By physically isolating the main fuel passage from the auxiliary fuel passage, the nozzle can flexibly select single-path or dual-path fuel supply according to operating conditions, thus structurally achieving graded and combined regulation of fuel flow.

[0015] An auxiliary air supply line 3 is installed at the inlet end of the compressed air passage. After the compressed gas enters the nozzle, it flows along the compressed air passage and is ejected from the compressed air outlet 12. The compressed air outlet 12 is located near the nozzle tip 10 of the main fuel line and the nozzle tip 11 of the auxiliary fuel line, so that the compressed gas can directly act on the fuel film and droplet formation area after being ejected, forming a strong gas-liquid coupling atomization environment near the nozzle outlet.

[0016] like Figure 2 As shown, the atomization system includes a fuel tank 18, a fuel separator 17, a gear pump 16, a main fuel line pressure control valve 13, a secondary fuel line pressure control valve 14, and an ECU control unit 15. The fuel tank 18 stores fuel to be atomized. After flowing out of the fuel tank 18, the fuel enters the fuel separator 17, which separates gases and impurities entrained in the fuel to improve the stability of the fuel entering the nozzle. The fuel processed by the fuel separator 17 then enters the gear pump 16, which pressurizes and delivers the fuel.

[0017] A main fuel supply line 1 is equipped with a main fuel line pressure control valve 13, and an auxiliary fuel supply line 2 is equipped with an auxiliary fuel line pressure control valve 14. The main fuel line pressure control valve 13 and the auxiliary fuel line pressure control valve 14 are respectively connected to the ECU control unit 15. They are used to independently adjust the fuel pressure of the main fuel line and the auxiliary fuel line under the condition of sharing the same gear pump 16, so that the main fuel line supply line 1 and the auxiliary fuel line supply line 2 can obtain different and adjustable fuel supply pressures.

[0018] Figure 3 This diagram illustrates the wide-load regulation and control method of the present invention. Under low-load conditions, the system's demand for fuel flow and supply pressure is significantly reduced. If relying solely on swirling action, problems such as insufficient swirling intensity, increased liquid film thickness, and decreased liquid film breaking ability can easily occur. The present invention, under this condition, can employ a working mode where only the main fuel line is supplied with fuel. The fuel in the main fuel line forms a rotating liquid film under the action of the swirler 7 and is ejected from the nozzle tip 10 of the main fuel line. Simultaneously, no fuel is supplied to the auxiliary fuel line fuel inlet 2. The auxiliary fuel line channel is used to introduce swirling compressed air or auxiliary compressed air, causing the compressed gas to be ejected through the nozzle tip 11 of the auxiliary fuel line or the adjacent compressed air outlet 12, forming a high-speed airflow shear layer outside the fuel liquid film in the main fuel line. This high-speed airflow shear layer strongly disturbs the rotating liquid film, enabling effective breaking of the liquid film even under low fuel flow conditions, thereby achieving fine atomization injection under low-load conditions and improving combustion stability.

[0019] Under medium load conditions, this invention employs a combined operating mode of main fuel supply, auxiliary fuel supply, and simultaneous introduction of compressed air. The fuel in the main fuel supply forms a primary rotating liquid film under the action of the cyclone separator, while the fuel in the auxiliary fuel supply participates in the injection as supplementary flow, forming a composite liquid film structure together with the main fuel supply in the nozzle outlet region. The compressed air continuously applies a shearing force to the outer side of the liquid film, maintaining a stable breakup position and droplet distribution during the breakup process. This achieves smooth adjustment of the fuel flow rate and avoids abrupt changes in spray pattern during load variations.

[0020] Under high-load conditions, this invention employs a simultaneous fuel supply mode using both the main and auxiliary fuel lines. The dual-line fuel superposition satisfies the system's demand for high-flow-rate fuel injection. The fuel in the main line maintains a strong rotational state under the action of the cyclone separator 7, while the fuel in the auxiliary line participates in injection on the outer side, forming an outer liquid film. Compressed air is ejected from the compressed air outlet 12, applying high-speed shearing action to both the inner and outer fuel liquid films simultaneously. This ensures that the liquid films can still break up in time and suppress droplet aggregation under high-flow-rate conditions, thus balancing high-flow-rate fuel injection capability with spray stability under high-load conditions.

[0021] Furthermore, depending on the characteristics of different fuels or the requirements of control strategies, the present invention can also adopt a variety of extended operating modes. For example, under conditions of high fuel viscosity or low ambient temperature, the liquid film shearing and breaking capacity can be enhanced by increasing the compressed air flow rate and adjusting the fuel supply ratio between the main oil circuit and the auxiliary oil circuit; under conditions of rapid load changes, the rapid response and stable transition of the spray pattern can be achieved by switching the fuel supply channel in stages or changing the compressed air injection mode.

[0022] Through the flexible combination of the above-mentioned multiple working modes, the nozzle of the present invention can maintain high atomization efficiency and injection stability under low load, medium load and high load conditions, realize ultra-fine atomization injection over a wide load range, and is suitable for application scenarios with high requirements for combustion stability, emission performance and system reliability.

Claims

1. A dual-oil-path air-assisted ultrafine atomizing nozzle suitable for wide-load operating conditions, characterized in that: The system comprises a main oil circuit housing, a secondary oil circuit housing, and a gas circuit housing. The secondary oil circuit housing is installed outside the main oil circuit housing, and the gas circuit housing is installed outside the secondary oil circuit housing. A main oil circuit supply pipeline is located inside the main oil circuit housing, and a secondary oil circuit supply pipeline is located inside the secondary oil circuit housing. An auxiliary gas supply pipeline is formed between the gas circuit housing and the secondary oil circuit housing. A cyclone separator is installed in the main oil circuit supply pipeline. The upper part of the cyclone separator is engaged with a protrusion on the inner wall of the main oil circuit housing, and a cyclone groove is formed between the lower part of the cyclone separator and the inner wall of the main oil circuit housing. A cyclone chamber is formed in the main oil circuit housing below the cyclone groove.

2. The dual-oil-path gas-assisted ultra-fine atomizing nozzle suitable for wide-load operating conditions according to claim 1, characterized in that: The bottom of the main oil supply line is the nozzle end of the main oil supply line, the bottom of the auxiliary oil supply line is the nozzle end of the auxiliary oil supply line, and the bottom of the auxiliary air supply line is the compressed air outlet. The nozzle ends of the main oil supply line, the nozzle ends of the auxiliary oil supply line, and the compressed air outlet converge at one place.

3. The dual-oil-path gas-assisted ultrafine atomizing nozzle suitable for wide-load operating conditions according to claim 1, characterized in that: The vortex chamber is funnel-shaped.

4. An atomizing system, characterized in that: The system includes an ECU control unit, an oil tank, a gear pump, an air source, a main oil circuit pressure control valve, a secondary oil circuit pressure control valve, an auxiliary air pressure control valve, and an atomizing nozzle as described in claim 1. The oil tank is connected to the gear pump. The main oil circuit pressure control valve and the secondary oil circuit pressure control valve are connected in parallel and then connected to the gear pump. The main oil circuit supply line of the atomizing nozzle is connected to the main oil circuit pressure control valve. The secondary oil circuit supply line of the atomizing nozzle is connected to the secondary oil circuit pressure control valve. The air source is connected to the auxiliary air pressure control valve. The auxiliary air pressure control valve is connected to the auxiliary air supply line of the atomizing nozzle. The ECU control unit is connected to the main oil circuit pressure control valve, the secondary oil circuit pressure control valve, and the auxiliary air pressure control valve, respectively.

5. The atomizing system according to claim 4, characterized in that: An oil separator is installed between the oil tank and the gear pump.

6. A fuel injection control method, characterized in that: Using the atomization system as described in claim 4, the oil quantity requirement is determined as follows: when the oil quantity is less than or equal to 150 kg / h, it is determined to be a low-load condition; when the oil quantity is greater than 150 kg / h and less than 300 kg / h, it is determined to be a medium-load condition; and when the oil quantity is greater than or equal to 300 kg / h, it is determined to be a high-load condition. Under low load conditions, the main oil circuit is used as the only oil supply mode. The fuel in the main oil circuit forms a rotating liquid film under the action of the cyclone separator and is sprayed out from the nozzle tip of the main oil circuit. The auxiliary oil circuit fuel inlet does not supply fuel, but is used to introduce swirling compressed air or auxiliary compressed air, so that the compressed gas is ejected through the nozzle tip of the auxiliary oil circuit or the adjacent compressed air outlet, forming a high-speed airflow shear layer on the outside of the fuel liquid film in the main oil circuit. Under medium load conditions, a composite working mode is adopted, which involves main oil circuit fuel supply, auxiliary oil circuit supplementary fuel supply, and simultaneous introduction of compressed air. The fuel in the main oil circuit forms a main rotating liquid film under the action of the cyclone separator, while the fuel in the auxiliary oil circuit participates in the injection as a supplementary flow. Together with the fuel in the main oil circuit, they form a composite liquid film structure in the nozzle outlet area. The compressed air continuously applies a shearing action to the outside of the liquid film, so that the liquid film maintains a stable rupture position and droplet distribution during the breakup process. Under heavy load conditions, the system adopts a working mode of simultaneous fuel supply from the main oil circuit and the auxiliary oil circuit. The system meets the demand for high-flow fuel injection by superimposing fuel from the dual oil circuits: the fuel in the main oil circuit is kept in a rotating state under the action of the cyclone separator, while the fuel in the auxiliary oil circuit participates in the injection on the outside and forms an outer liquid film; compressed air is ejected from the compressed air outlet, which simultaneously applies high-speed shear to the inner and outer fuel liquid films, so that the liquid film can be broken up and droplet co-aggregation can be inhibited under high flow conditions.

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