Combined type intercooling system based on fuel oil precooling, micro vortex tube and waste gas recycling

Abstract

The invention discloses a combined type intercooling system based on fuel oil precooling, a micro vortex tube and waste gas reutilization. The combined type intercooling system comprises a first-stage cooling unit, a second-stage cooling unit and a third-stage cooling unit which are sequentially connected in the flowing direction of air entering an engine. The first-stage cooling unit is used for utilizing fuel oil as a primary cold source, conducting primary cooling on pressurized air and waste gas of an engine and preheating the fuel oil at the same time. The second-stage cooling unit is used for introducing high-pressure driving airflow to generate low-temperature airflow and deeply cooling the pressurized air and the waste gas which are primarily cooled; the third-stage cooling unit is used for mixing the pressurized air subjected to deep cooling with the waste gas so as to control the temperature of inlet air finally entering the engine; according to the invention, three-stage composite cooling is sequentially carried out on supercharged air through fuel oil pre-cooling, micro vortex tube cooling and waste gas mixing, so that accurate control on the temperature of air entering an engine is realized.

Description

Technical Field

[0001] This invention relates to the field of piston aero-engine technology, and more specifically to a combined intercooling system based on fuel precooling, micro vortex tubes, and exhaust gas reuse. Background Technology

[0002] Turbocharging technology can significantly improve the power density of an engine, but the high-temperature intake air after turbocharging can lead to increased engine knocking tendency and decreased thermal efficiency. Therefore, an intercooler is needed to cool the turbocharged air. Traditional air-to-air intercoolers are limited by ambient temperature, resulting in an upper limit to their cooling efficiency; water-to-air intercooler systems are complex and present thermal management challenges.

[0003] Existing technologies also include the concept of using fuel as a cold source. However, a single fuel cooler may not be able to provide sufficient cooling capacity under high engine load and high boost pressure due to the relatively limited fuel flow, resulting in inadequate intake air cooling. While vortex tubes can generate low-temperature airflow, their overall cooling efficiency is not high. If used alone to cool all the intake air, the energy consumption would be too high, making it uneconomical.

[0004] Therefore, how to overcome the limitations of existing technologies and design an intercooling system that can achieve efficient and stable cooling under any operating conditions has become an urgent problem to be solved in this field. Summary of the Invention

[0005] The purpose of this invention is to provide a composite intercooling system based on fuel precooling, micro vortex tube and exhaust gas reuse. Through fuel precooling, micro vortex tube cooling and exhaust gas mixing, the pressurized air is cooled in three stages to achieve precise control of the intake air temperature entering the engine.

[0006] To achieve the above objectives, the present invention provides the following technical solution: A composite intercooling system based on fuel precooling, micro vortex tubes, and exhaust gas reuse includes a primary cooling unit, a secondary cooling unit, and a tertiary cooling unit connected sequentially along the airflow direction into the engine. The primary cooling unit is used to use fuel as a primary cold source to initially cool the boosted air and engine exhaust gas, while preheating the fuel. The secondary cooling unit is used to introduce high-pressure driving airflow to generate low-temperature airflow, which deeply cools the pre-cooled pressurized air and the exhaust gas emitted by the engine. The three-stage cooling unit is used to mix the deeply cooled boosted air with the exhaust gas in order to control the final intake air temperature entering the engine.

[0007] Furthermore, the primary cooling unit is a fuel cooler; the fuel cooler is located on the engine's fuel supply line. The first air inlet of the fuel cooler is connected to the outlet of the turbocharger for preliminary cooling of the boosted air; The second air inlet of the fuel cooler is connected to the exhaust port of the engine, and is used to initially cool the exhaust gas of the engine and preheat the fuel.

[0008] Furthermore, the fuel cooler employs a plate-fin heat exchanger; A proportional control valve is installed between the air inlet of the plate-fin heat exchanger and the turbocharger. The intake port of the proportional control valve is connected to the outlet of the turbocharger; The first outlet of the proportional control valve is connected to the first inlet of the plate-fin heat exchanger. The second outlet of the proportional control valve leads to a drive air path that connects to the third air inlet of the secondary cooling unit to drive the operation of the secondary cooling unit.

[0009] Furthermore, the engine exhaust port is also equipped with a CNC engine exhaust gas recirculation valve, which is used to control the amount of exhaust gas entering the plate-fin heat exchanger from the engine exhaust port, so as to reduce the engine combustion temperature and suppress nitrogen oxide emissions.

[0010] Furthermore, the secondary cooling unit is a micro vortex tube cooler; The first air inlet of the micro vortex tube cooler is connected to the first air outlet of the plate-fin heat exchanger; the second air inlet of the micro vortex tube cooler is connected to the second air outlet of the plate-fin heat exchanger. The third air inlet of the micro vortex tube cooler is connected to the second outlet of the proportional control valve to introduce high-pressure driving airflow and generate low-temperature airflow using the vortex tube effect to deeply cool the pre-cooled pressurized air and exhaust gas.

[0011] Furthermore, the three-stage cooling unit is a compact air-to-air intercooler; The first air inlet of the compact air-to-air cooler is connected to the first air outlet of the micro vortex tube cooler, and the second air inlet of the compact air-to-air cooler is connected to the second air outlet of the micro vortex tube cooler, for mixing the deeply cooled pressurized air with the exhaust gas to obtain a mixed gas. The mixed gas enters the engine's combustion chamber through the outlet of the compact air-to-air intercooler.

[0012] Furthermore, the intercooling system also includes: an intelligent control system; The intelligent control system includes: an engine load sensor, a control unit, and an intake air temperature sensor; The intake air temperature sensor is used to collect the final intake air temperature before it enters the engine in real time and feed it back to the control unit. The engine load sensor is used to acquire the engine load status in real time in order to determine the engine's requirement for intake air cooling. The control unit is used to intelligently adjust the opening of the proportional control valve based on the engine's real-time load status, the preset target intake air temperature, and the real-time temperature fed back by the intake air temperature sensor.

[0013] Furthermore, the control logic of the control unit is as follows: When the engine requires a relatively high temperature, the control unit reduces or closes the opening of the proportional control valve, relies on the fuel cooler to perform preliminary cooling of the boosted air and exhaust gas, and the micro vortex tube cooler is in a non-working or low power consumption state. When the engine requires a relatively low temperature, the control unit increases the opening of the proportional control valve to increase the airflow driving the micro vortex tube cooler, thereby generating a low-temperature airflow to deeply cool the pre-cooled boosted air and exhaust gas.

[0014] According to specific embodiments provided by the present invention, the present invention has the following technical effects compared to the prior art: This invention utilizes fuel as a cold source to absorb heat, achieving preliminary cooling of the boosted air and exhaust gas, as well as fuel preheating, without consuming additional energy. This improves both intake air density and fuel atomization performance. Deep cooling is achieved through the generation of low-temperature airflow via micro-vortex tubes, effectively overcoming the heat exchange bottleneck of traditional intercoolers under extreme conditions and significantly reducing intake air temperature. By mixing the deeply cooled air with exhaust gas, the final intake air temperature can be flexibly adjusted, suppressing engine knock, improving charging efficiency, and fully utilizing exhaust gas energy, thereby comprehensively improving engine power, economy, and emissions. By synergistically coupling fuel precooling with deep vortex tube cooling and exhaust gas reuse technology, the limitations of single cooling methods are overcome, achieving efficient, stepped cooling of the boosted intake air under all operating conditions. This greatly improves intake air density while simultaneously optimizing fuel atomization and reducing nitrogen oxide emissions. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0016] The present invention will be further described below with reference to the accompanying drawings. Figure 1 This is a schematic diagram of a composite intercooling system based on fuel precooling, micro vortex tubes, and exhaust gas reuse in an embodiment of the present invention.

[0017] In the attached diagram: 1. Turbocharger; 2. Proportional control valve; 3. Fuel cooler; 4. Miniature vortex tube cooler; 5. Compact air-to-air intercooler; 6. CNC engine exhaust gas recirculation valve; 7. Engine; 8. Intelligent control system; 81. Engine load sensor; 82. Control unit; 83. Intake air temperature sensor. Detailed Implementation

[0018] The specific embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and are not intended to limit the scope of the invention.

[0019] To better understand the purpose, structure, and function of this invention, the invention will be described in further detail below with reference to the accompanying drawings.

[0020] As shown in the figure, the present invention provides a composite intercooling system based on fuel precooling, micro vortex tube and exhaust gas reuse, including a primary cooling unit, a secondary cooling unit and a tertiary cooling unit connected in sequence along the airflow direction entering the engine 7. The primary cooling unit is used to use fuel as a primary cold source to initially cool the boosted air and the exhaust gas of engine 7, while preheating the fuel. In this embodiment, the use of low-temperature fuel to absorb heat from the pressurized air and exhaust gas not only reduces the intake air temperature (increases the intake air density) but also heats the fuel, improving the fuel atomization and evaporation performance, which is beneficial to the complete combustion of the engine, while reducing the heat load on the radiator in the traditional cooling system.

[0021] The secondary cooling unit is used to introduce high-pressure driving airflow to generate low-temperature airflow, which deeply cools the pre-cooled pressurized air and the exhaust gas emitted by engine 7. In this embodiment, when the primary cooling cannot meet the requirements (such as under high load conditions), the high-pressure airflow generates a low-temperature effect, which can further reduce the intake air temperature to below the ambient temperature, breaking through the "temperature drop bottleneck" of traditional air-cooled or water-cooled intercoolers, and significantly improving the engine's power output and anti-knock performance.

[0022] The three-stage cooling unit is used to mix the deeply cooled boosted air with the exhaust gas in order to control the intake air temperature that finally enters the engine 7.

[0023] This embodiment mixes deeply cooled air with exhaust gas and uses the exhaust gas to regulate (usually by finely adjusting the heating or mixing) the final intake air temperature, preventing excessively low temperatures from causing condensate corrosion or unstable combustion, and ensuring that the gas temperature entering the engine is within the optimal combustion range.

[0024] The primary cooling unit is a fuel cooler 3; the fuel cooler 3 is located on the fuel supply line of the engine 7. The first air inlet of the fuel cooler 3 is connected to the outlet of the turbocharger 1 for preliminary cooling of the boosted air. The second air inlet of the fuel cooler 3 is connected to the exhaust outlet of the engine 7, and is used to initially cool the exhaust gas of the engine 7 and preheat the fuel.

[0025] This embodiment employs an integrated design (with the first and second air intakes handling different airflows), resulting in a compact structure, reduced piping connections, simplified system layout, and easier installation within the limited space of the engine compartment. Pre-treatment of the high-temperature, high-pressure air after turbocharging directly reduces the heat load on the subsequent secondary cooling unit, improving the overall system cooling efficiency. Pre-treatment of the high-temperature EGR exhaust gas lowers its temperature to protect downstream components (such as the vortex tube), while the high enthalpy of the exhaust gas allows for more efficient fuel heating, achieving efficient waste heat recovery.

[0026] The fuel cooler 3 is a plate-fin heat exchanger. A proportional control valve 2 is installed between the air inlet of the plate-fin heat exchanger and the turbocharger 1. The intake port of the proportional control valve 2 is connected to the outlet of the turbocharger 1. The first air outlet of the proportional control valve 2 is connected to the first air inlet of the plate-fin heat exchanger. The second outlet of the proportional control valve 2 leads to a drive air path that connects to the third air inlet of the secondary cooling unit to drive the operation of the secondary cooling unit.

[0027] In this embodiment, the plate-fin heat exchanger features high heat transfer efficiency, compact structure, lightweight and strong adaptability. It can adapt to the narrow space inside the engine compartment and achieve efficient heat exchange within a limited volume. The proportional control valve 2 enables the system to flexibly adjust the cooling intensity according to different operating conditions. It also directly utilizes the pressurized high-pressure gas source as the control object, ensuring sufficient pressure for both the driving and cooling airflows. No additional pressurization device is required, reducing system complexity.

[0028] The exhaust port of the engine 7 is also equipped with a CNC exhaust gas recirculation valve 6, which is used to control the amount of exhaust gas entering the plate-fin heat exchanger from the exhaust port of the engine 7, so as to reduce the combustion temperature of the engine and suppress nitrogen oxide emissions. The secondary cooling unit is a micro vortex tube cooler 4; The first air inlet of the micro vortex tube cooler 4 is connected to the first air outlet of the plate-fin heat exchanger; the second air inlet of the micro vortex tube cooler 4 is connected to the second air outlet of the plate-fin heat exchanger. The third air inlet of the micro vortex tube cooler 4 is connected to the second outlet of the proportional control valve 2 to introduce high-pressure driving airflow. The vortex tube effect is used to generate low-temperature airflow to deeply cool the pre-cooled pressurized air and exhaust gas. This realizes a series architecture of staged cooling, ensuring that the gas is first preheated / precooled by fuel and then deeply cooled by the micro vortex tube cooler 4, step by step, maximizing the utilization rate of heat exchange temperature difference.

[0029] The three-stage cooling unit is a compact air-to-air intercooler 5; The first air inlet of the compact air-to-air intercooler 5 is connected to the first air outlet of the micro vortex tube cooler 4, and the second air inlet of the compact air-to-air intercooler 5 is connected to the second air outlet of the micro vortex tube cooler 4, for mixing the deeply cooled pressurized air with the exhaust gas to obtain a mixed gas. The mixed gas enters the engine combustion chamber through the outlet of the compact air-to-air intercooler 5.

[0030] In this embodiment, the compact air-to-air intercooler serves as a mixing device. Its internal flow channel design enables effective gas mixing and final temperature control. It has a simple structure and high reliability, achieving uniform mixing of low-temperature boosted air and low-temperature EGR exhaust gas. This ensures that the gas composition and temperature field entering engine 7 are uniform, which is beneficial to the combustion balance of each cylinder. It also ensures that the intake air temperature supplied to engine 7 is precisely controlled, optimizes the combustion environment, and improves the engine's thermal efficiency and emission performance.

[0031] The intercooling system also includes: Intelligent Control System 8; The intelligent control system 8 includes: an engine load sensor 81, a control unit 82, and an intake air temperature sensor 83; The intake air temperature sensor 83 is used to collect the final intake air temperature before it enters the engine 7 in real time and feed it back to the control unit 82. The engine load sensor 81 is used to acquire the load status of the engine 7 in real time in order to determine the engine 7's requirement level for intake air cooling. The control unit 82 is used to intelligently adjust the opening of the proportional control valve 2 according to the real-time load status of the engine 7, the preset target intake air temperature, and the real-time temperature fed back by the intake air temperature sensor 83.

[0032] In this embodiment, the introduction of the intelligent control system enables closed-loop dynamic adjustment of the intercooling process. Through the coordinated operation of the engine load sensor 81 and the intake air temperature sensor 83, the control unit 82 can accurately sense the load status of the engine 7 and the changes in intake air temperature in real time, and intelligently adjust the opening of the proportional control valve 2 accordingly. This not only allows for rapid and automatic adjustment of cooling efficiency based on the real-time cooling requirements of the engine 7, ensuring that the intake air temperature remains consistently within the preset optimal range, thereby optimizing the combustion efficiency of the engine 7, improving power output, and reducing fuel consumption; but also effectively avoids potential hazards such as condensate buildup due to over-cooling or engine knocking due to insufficient cooling, significantly improving the system's operational reliability and the overall service life of the engine.

[0033] The control logic of the control unit 82 is as follows: When the engine 7 requires a relatively high temperature, the control unit 82 reduces or closes the opening of the proportional control valve 2, and relies on the fuel cooler 3 to perform preliminary cooling of the boosted air and exhaust gas. The micro vortex tube cooler 4 is in a non-working or low-power state. When the required temperature of engine 7 is relatively low, the control unit 82 increases the opening of the proportional control valve 2 to increase the airflow driving the micro vortex tube cooler 4, so as to generate a low-temperature airflow to deeply cool the pre-cooled boosted air and exhaust gas.

[0034] In this embodiment, the engine controller intelligently adjusts the opening of the proportional control valve 2 based on real-time collected parameters such as engine load and target intake air temperature, thereby precisely controlling the flow rate of ambient air entering the fuel cooler 3 and the micro vortex tube cooler 4.

[0035] When the required cooling load is low, the control unit 82 of the engine 7 can reduce or even close the proportional control valve 2. The system mainly relies on the high-efficiency fuel cooler 3 and ambient air for cooling. At this time, the micro vortex tube cooler 4 does not work or works with low power consumption, and the system energy consumption is at its lowest.

[0036] When the intake air temperature cannot be reduced to the ideal range by relying solely on the efficient fuel cooler 3 and ambient air, the control unit 82 of the engine 7 increases the opening of the proportional control valve 2, and introduces more high-pressure air through the turbocharger 1 to drive the fuel cooler 3 and the micro vortex tube cooler 4 to generate a strong low-temperature airflow, which provides "reinforced" deep cooling for the intake air, so as to ensure that the intake air temperature entering the engine 7 is always in the optimal range.

[0037] The above description of the disclosed embodiments enables those skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A composite intercooling system based on fuel precooling, micro-vortex tubes, and exhaust gas reuse, characterized in that, It includes a primary cooling unit, a secondary cooling unit, and a tertiary cooling unit connected sequentially along the airflow direction into the engine (7); The primary cooling unit is used to use fuel as a primary cold source to initially cool the boosted air and the exhaust gas of the engine (7), while preheating the fuel. The secondary cooling unit is used to introduce high-pressure driving airflow to generate low-temperature airflow, and to deeply cool the pre-cooled pressurized air and the exhaust gas emitted by the engine (7). The three-stage cooling unit is used to mix the deeply cooled pressurized air with the exhaust gas to control the intake air temperature that finally enters the engine (7).

2. The intercooling system based on fuel precooling, micro-vortex tubes, and exhaust gas reuse as described in claim 1, characterized in that, The primary cooling unit is a fuel cooler (3); the fuel cooler (3) is located on the fuel supply line of the engine (7); The first air inlet of the fuel cooler (3) is connected to the outlet of the turbocharger (1) for preliminary cooling of the boosted air; The second air inlet of the fuel cooler (3) is connected to the exhaust outlet of the engine (7) for preliminary cooling of the exhaust gas of the engine (7) and preheating of the fuel.

3. The intercooling system based on fuel precooling, micro-vortex tubes, and exhaust gas reuse according to claim 2, characterized in that, The fuel cooler (3) adopts a plate-fin heat exchanger; A proportional control valve (2) is installed between the air inlet of the plate-fin heat exchanger and the turbocharger (1). The intake port of the proportional control valve (2) is connected to the outlet of the turbocharger (1); The first outlet of the proportional control valve (2) is connected to the first inlet of the plate-fin heat exchanger. The second outlet of the proportional control valve (2) leads to a drive air path that is connected to the third air inlet of the secondary cooling unit to drive the secondary cooling unit to operate.

4. The intercooling system based on fuel precooling, micro-vortex tubes, and exhaust gas reuse according to claim 3, characterized in that, The exhaust port of the engine (7) is also equipped with a numerically controlled engine exhaust gas recirculation valve (6) to control the amount of exhaust gas entering the plate-fin heat exchanger from the exhaust port of the engine (7) in order to reduce the combustion temperature of the engine (7) and suppress nitrogen oxide emissions.

5. The intercooling system based on fuel precooling, micro-vortex tubes, and exhaust gas reuse according to claim 3, characterized in that, The secondary cooling unit is a micro vortex tube cooler (4). The first air inlet of the micro vortex tube cooler (4) is connected to the first air outlet of the plate-fin heat exchanger; the second air inlet of the micro vortex tube cooler (4) is connected to the second air outlet of the plate-fin heat exchanger. The third air inlet of the micro vortex tube cooler (4) is connected to the second outlet of the proportional control valve (2) to introduce high-pressure driving airflow and generate low-temperature airflow by utilizing the vortex tube effect to deeply cool the pressurized air and exhaust gas after preliminary cooling.

6. The intercooling system based on fuel precooling, micro-vortex tubes, and exhaust gas reuse according to claim 4, characterized in that, The three-stage cooling unit is a compact air-to-air intercooler (5). The first air inlet of the compact air-to-air cooler (5) is connected to the first air outlet of the micro vortex tube cooler (4), and the second air inlet of the compact air-to-air cooler (5) is connected to the second air outlet of the micro vortex tube cooler (4), which is used to mix the deeply cooled pressurized air with the exhaust gas to obtain a mixed gas. The mixed gas enters the combustion chamber of the engine through the outlet of the compact air-to-air intercooler (5).

7. The intercooling system based on fuel precooling, micro-vortex tubes, and exhaust gas reuse according to claim 1, characterized in that, The intercooling system also includes: intelligent control system (8); The intelligent control system (8) includes: an engine load sensor (81), a control unit (82), and an intake air temperature sensor (83). The intake air temperature sensor (83) is used to collect the final intake air temperature before it enters the engine (7) in real time and feed it back to the control unit (82). The engine load sensor (81) is used to acquire the load status of the engine (7) in real time in order to determine the engine (7)’s demand level for intake air cooling. The control unit (82) is used to intelligently adjust the opening of the proportional control valve (2) according to the real-time load status of the engine (7), the preset target intake air temperature and the real-time temperature fed back by the intake air temperature sensor (83).

8. The intercooling system based on fuel precooling, micro-vortex tubes, and exhaust gas reuse according to claim 7, characterized in that, The control logic of the control unit (82) is as follows: When the engine (7) requires a relatively high temperature, the control unit (82) reduces or closes the opening of the proportional control valve (2), relies on the fuel cooler (3) to perform preliminary cooling of the boosted air and exhaust gas, and the micro vortex tube cooler (4) is in a non-working or low power consumption state. When the required temperature of the engine (7) is relatively low, the control unit (82) increases the opening of the proportional control valve (2) to increase the airflow driving the micro vortex tube cooler (4) to generate a low-temperature airflow to deeply cool the pre-cooled pressurized air and exhaust gas.

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