A helicopter lubricating oil cooling device and cooling method

Abstract

This invention discloses a helicopter lubricating oil cooling device and method. The need for cooling is determined by the lubricating oil temperature. When the lubricating oil temperature is higher than the operating temperature range, the lubricating oil is fed into an air-oil cooler for cooling before returning to the oil tank. When the lubricating oil temperature is within the operating temperature range, the lubricating oil returns directly to the oil tank. The helicopter lubricating oil cooling device includes an air-oil cooler, an electrically driven axial fan, a temperature and pressure sensing valve, a transition duct, a temperature sensor, and a control box. The air intake of the electrically driven axial fan is connected to the cold-side air outlet of the air-oil cooler via the transition duct. The temperature and pressure sensing valve is connected to both the hot-side lubricating oil inlet and outlet of the air-oil cooler. The temperature sensor inputs the lubricating oil temperature at the front end of the hot-side lubricating oil inlet to the control box, which then controls the rotational speed of the electrically driven axial fan. This invention meets the technical requirements of low power consumption, wide applicable operating conditions, and high reliability for helicopter lubricating oil cooling systems.

Description

Technical Field

[0001] This invention relates to a lubricating oil cooling system for helicopters, specifically a lubricating oil cooling device and method consisting of a high-voltage DC fan and an air-oil cooler, applicable to engine lubricating oil cooling in equipment in the fields of aviation, aerospace, shipbuilding, and weaponry. Background Technology

[0002] An oil cooling system is a mechanical device used to cool lubricating oil in machines and is widely used in aviation, aerospace, shipbuilding, automotive and other fields.

[0003] When the engine and main reducer are running, components such as bearings and gears generate a lot of heat, all of which need to be cooled by lubricating oil. However, the control of lubricating oil temperature and the reliability of lubricating oil cooling systems / equipment have always been challenges in the domestic aviation industry. In particular, the application of lubricating oil cooling systems with low power consumption, wide applicable operating conditions, and high reliability is a key research focus. In order to solve the problems of low power consumption, wide applicable operating conditions, and high reliability of lubricating oil cooling systems, it is urgent to design a lubricating oil cooling system and cooling method for helicopters. Summary of the Invention

[0004] The present invention aims to provide a lubricating oil cooling device and cooling method for helicopters according to the specified technical indicators such as heat dissipation and structural dimensions, so as to meet the technical requirements of low power consumption, wide range of applicable operating conditions and high reliability.

[0005] To solve the above problems, the present invention adopts the following technical solution:

[0006] The helicopter lubricating oil cooling method uses an air-cooled radiator and includes the following steps:

[0007] S1, measure the lubricating oil temperature T1 before entering the air-cooled radiator. If T1 is higher than the normal working oil temperature range of the lubricating oil in the lubricating oil system, execute S2. If T1 falls within the normal working oil temperature range of the lubricating oil in the lubricating oil system, execute S3.

[0008] S2, lubricating oil at temperature T1 is introduced into the hot-side lubricating oil inlet of the air-cooled radiator, and the lubricating oil is cooled by the air-cooled radiator. A fan is installed at the cold-side air outlet of the air-cooled radiator. The air intake volume of the cold-side air inlet of the air-cooled radiator is calculated based on the lubricating oil temperature T1 measured in S1, and the air intake volume is converted into the fan speed. By controlling the fan speed, air that meets the air intake volume requirements is supplied to the cold-side air inlet of the air-cooled radiator.

[0009] S3, which bypasses the air-cooled radiator and outputs lubricating oil directly to the lubricating oil tank for later use.

[0010] Furthermore, in S1, a temperature-sensing valve connected to the hot-side lubricating oil inlet and hot-side lubricating oil outlet of the air-cooled radiator is used to control the flow direction of the lubricating oil. When T1 is higher than the operating temperature of the temperature-sensing element of the temperature-sensing valve, the temperature-sensing valve closes and S2 is executed. When T1 is lower than the operating temperature of the temperature-sensing element of the temperature-sensing valve, the temperature-sensing valve opens and S3 is executed.

[0011] Furthermore, in S2, the fan is a DC-driven axial fan.

[0012] As one approach, S2 further includes measuring the lubricating oil pressure at the hot-side lubricating oil inlet of the air-cooled radiator, and executing S3 when the lubricating oil pressure is greater than a set value.

[0013] A helicopter oil cooling device includes:

[0014] An air-oil radiator, comprising a cold-side air inlet, a cold-side air outlet, a hot-side oil inlet, and a hot-side oil outlet;

[0015] An electrically driven axial fan, wherein the air intake side of the electrically driven axial fan is connected to the cold side air outlet of an air-oil radiator;

[0016] A temperature- and pressure-sensitive valve includes a first cavity, a second cavity, a temperature-sensing element, a pressure-sensing element, and a valve. The first cavity has a first lubricating oil inlet and a first lubricating oil outlet, and the second cavity has a second lubricating oil inlet and a second lubricating oil outlet. The first lubricating oil inlet is connected to the hot-side lubricating oil outlet, and the second lubricating oil outlet is connected to the hot-side lubricating oil inlet. The temperature-sensing element and the pressure-sensing element are connected to the valve. The valve is normally open and is positioned between the first cavity and the second cavity to maintain communication between the two cavities. When the temperature-sensing element is activated, the valve closes; when the valve is closed and the pressure-sensing element is activated, the valve opens.

[0017] A temperature sensor is located upstream of the temperature- and pressure-sensitive valve and the air-oil radiator to measure the temperature of the lubricating oil before it enters the temperature- and pressure-sensitive valve and the air-oil radiator.

[0018] The control box receives electrical signals from a temperature sensor and outputs electrical signals to an electrically driven axial fan.

[0019] As one option, the temperature and pressure sensing valve is integrated into the hot-side lubricating oil inlet end cap of the air-oil radiator.

[0020] As one embodiment, the second lubricating oil inlet and the first lubricating oil outlet of the temperature- and pressure-sensitive valve are respectively connected to the hot-side lubricating oil inlet nozzle and the hot-side lubricating oil outlet nozzle of the air-oil radiator via threads.

[0021] As one embodiment, the air intake end of the electrically driven axial fan is connected to the cold side air outlet of the air-oil radiator via a transition duct. The transition duct is a variable cross-section shell that is open at both ends and closed circumferentially. The air intake end and exhaust end of the transition duct are respectively connected to the cold side air outlet of the air-oil radiator and the air intake end of the electrically driven axial fan.

[0022] As one option, the control box and the controller of the electric axial fan are integrated into one unit, which is integrated inside the electric axial fan and connected to the motor of the electric axial fan. The electric axial fan includes moving blades and guide blades, and the moving blades are located between the guide blades and the cold side air outlet of the air-oil radiator.

[0023] As one option, the motor of the electrically driven axial fan is a high-voltage DC motor, and the motor and controller of the electrically driven axial fan adopt a dual-redundancy design.

[0024] From an energy conversion perspective, the lubricating oil cooling system converts electrical energy into the kinetic and pressure energy of gas via a fan, and uses an air-oil radiator to exchange heat between the fan-input gas and the lubricating oil, ensuring the working temperature of the lubricating oil and the normal operation of the corresponding system / equipment. In the helicopter lubricating oil cooling device of this invention, an electrically driven axial fan draws in air axially, transferring cool air absorbed from the environment through a transition duct to the cold-side air inlet of the air-oil radiator. A certain inlet pressure is applied to the cool air, causing it to flow out from the cold-side air outlet of the air-oil radiator. The aircraft's lubricating oil enters the radiator through the hot-side lubricating oil inlet nozzle. Inside the radiator, the lubricating oil exchanges heat with the cool air flowing through it via heat-conducting fins, resulting in low-temperature lubricating oil that flows out from the hot-side lubricating oil outlet of the air-oil radiator and returns to the lubricating oil tank for reuse via a pipeline. A temperature sensor installed at the front end of the hot-side oil inlet nozzle of the air-oil radiator monitors the oil inlet temperature and feeds the signal back to the control box. The control box determines the required airflow from the cold-side air inlet of the radiator to meet the oil temperature and outputs a control signal for the speed of the electrically driven axial fan. This controls the fan speed and airflow, ensuring that the system meets oil cooling requirements while reducing energy consumption. A temperature- and pressure-sensitive valve connects the hot-side oil inlet and outlet pipes of the air-oil radiator. Under normal operating conditions, it is closed. When the radiator core is blocked or the oil temperature is too low to require cooling, the valve opens, allowing oil to flow directly to the oil tank instead of the air-oil radiator, reducing energy consumption and improving the reliability of the oil cooling system.

[0025] In this invention, low power consumption is achieved by adjusting the fan speed according to different lubricating oil temperatures, thereby reducing the power consumption of the electrically driven axial fan. Adjusting the fan speed and valve assembly opening according to different lubricating oil temperatures achieves heat dissipation requirements under various operating conditions, thus making it suitable for different applications. The reliability of the helicopter lubricating oil cooling device is mainly determined by the electrically driven axial fan. Except when the cooling demand is high during hovering, requiring the electrically driven axial fan to operate at full power, it can operate at low speeds under other conditions, thereby improving its reliability.

[0026] Due to the limited installation space inside helicopters, the weight and volume of air-oil radiators cannot be changed. Therefore, this invention uses an electrically driven axial fan to control the airflow (air volume) at the cold side air inlet of the air-oil radiator, which solves the problem of weight and volume limitations of air-oil radiators on the one hand, and reduces power consumption on the other.

[0027] Compared with existing technologies, this invention is applied to the internal lubrication system of helicopters. Compared with the fan products currently used in helicopters, the fan of this invention has a larger flow rate, higher efficiency, and a wider range of applicable operating conditions, which can significantly improve the operational reliability of aviation fan products. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the structure of the helicopter lubricating oil cooling device in this invention;

[0029] Figure 2 This is a schematic diagram of the working principle of the helicopter lubricating oil cooling device in this invention. In the figure, the arrow with the thin outline indicates the direction of airflow on the cold side, and the arrow with the thick outline indicates the direction of lubricating oil flow on the hot side.

[0030] Figure 3 This is a schematic diagram of the temperature and pressure sensing valve in this invention;

[0031] In the diagram: 1. Air-oil radiator, 2. Electrically driven axial fan, 3. Temperature and pressure sensing valve, 4. Transition air duct, 5. Temperature sensor (not shown). Figure 1 (As shown in the image), 6. Control box. Detailed Implementation

[0032] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0033] Based on the limitations of technical specifications such as radiator structure, fan structure, heat dissipation, and size, this invention has matched and optimized the radiator and fan, ultimately providing a helicopter oil cooling device. The device mainly consists of an air-oil radiator 1, an electrically driven axial fan 2, a temperature and pressure sensing valve 3, a transition duct 4, a temperature sensor 5, and a control box 6. The air-oil radiator 1 and the transition duct 4 are fixedly connected by bolts. The electrically driven axial fan 2 is bolted to the other side of the transition duct 4. The control box 6 is integrated with the controller of the electrically driven axial fan 2, located inside the fan 2, and connected to the fan motor by bolts.

[0034] The air-oil radiator 1, temperature and pressure sensing valve 3, transition air duct 4, and temperature sensor 5 in the helicopter lubricating oil cooling device adopt an integrated design, that is, integrate multiple functional components such as air-oil radiator 1, temperature and pressure sensing valve 3, transition air duct 4, and temperature sensor 5 into a single radiator component, and improve efficiency through optimized layout and coordinated control.

[0035] The electric-driven axial fan 2 is driven by an 800VDC high-voltage DC motor. The internal motor and controller of the fan adopt a dual-redundancy design. The control box 6 and the fan motor controller adopt an integrated design and are integrated inside the fan.

[0036] Since the outer contour of the air intake end of the electric axial fan 2 is cylindrical, while the outer contour of the cold side air outlet of the air-oil radiator 1 is square, the two are connected by a transition air duct 4 with a square-to-circular cross-section.

[0037] Temperature sensor 5, installed at the front end of the hot-side lubricating oil inlet nozzle of air-oil radiator 1, monitors the lubricating oil inlet temperature and feeds the temperature signal back to control box 6. Control box 6 determines the required airflow of the cold-side air inlet of the radiator to meet the lubricating oil temperature and outputs a speed control signal for the electric-driven axial fan 2. This controls the operating speed and airflow of the electric-driven axial fan 2, so that it can meet the lubricating oil cooling requirements while reducing the power consumption of the helicopter.

[0038] The temperature and pressure sensing valve 3 connects the hot-side lubricating oil inlet and outlet pipes of the air-oil radiator 1. When the heat exchange core of the air-oil radiator 1 becomes blocked or the lubricating oil temperature is low and cooling by the air-oil radiator 1 is not required, the temperature and pressure sensing valve 3 opens, allowing the lubricating oil to flow directly, thus reducing energy consumption on the machine. Figure 3This is a schematic diagram of the temperature and pressure sensing valve 3. The valve is built into the housing of the hot-side lubricating oil end cap of the air-oil radiator 1, and is divided into a first chamber and a second chamber. It has a first lubricating oil inlet, a second lubricating oil inlet, a first lubricating oil outlet, and a second lubricating oil outlet. When the lubricating oil temperature is below a certain requirement, the valve is open. The lubricating oil does not require cooling from the air-oil radiator 1 and flows directly from the hot-side lubricating oil inlet nozzle through the second lubricating oil inlet to the second chamber and the first chamber, finally flowing out from the first lubricating oil outlet and the hot-side lubricating oil outlet nozzle. When the lubricating oil temperature is above a certain requirement, the temperature sensing element deforms, driving the valve to move and close the connection between the first and second chambers, i.e., it is closed. The lubricating oil enters the hot-side lubricating oil inlet of the air-oil radiator 1 through the second lubricating oil outlet and the cooling core for cooling, then flows from the hot-side lubricating oil outlet through the first lubricating oil inlet into the first chamber, and finally flows out from the first lubricating oil outlet and the hot-side lubricating oil outlet nozzle. When the valve is closed, if the heat dissipation core is blocked, the valve pressure sensing element will be activated due to the pressure difference between the first cavity and the second cavity, opening the valve in the opposite direction. The lubricating oil will not pass through the heat dissipation core of the air-lubricating oil radiator 1, but will flow directly from the second lubricating oil inlet through the second cavity, the valve, the first cavity, and the first lubricating oil outlet.

[0039] The air-oil radiator 1 and the temperature and pressure sensing valve 3 are integrated into one unit, such as... Figure 1 and Figure 3 The temperature and pressure sensing valve 3 is integrated inside the hot-side lubricating oil inlet end cap of the air-oil radiator 1. The second lubricating oil inlet and the first lubricating oil outlet of the temperature and pressure sensing valve are respectively connected to the hot-side lubricating oil inlet nozzle and the hot-side lubricating oil outlet nozzle on the hot-side lubricating oil inlet end cap of the air-oil radiator 1 by threaded connection.

[0040] The working principle of the helicopter lubricating oil cooling device of the present invention is as follows:

[0041] When the helicopter lubricating oil cooling device is working, the electrically driven axial fan 2 draws in air axially and transfers the cold air absorbed from the environment to the cold side air inlet of the air-oil cooler 1 through the transition air duct 4. The cold air is given a certain inlet pressure and flows out from the cold side air outlet of the air-oil cooler 1. The lubricating oil on the aircraft enters the interior of the air-oil cooler 1 through the hot side lubricating oil inlet nozzle. The lubricating oil flowing through the interior of the air-oil cooler 1 exchanges heat with the cold air flowing through the air-oil cooler 1 through the heat-conducting fins, thereby obtaining low-temperature lubricating oil, which flows out from the hot side lubricating oil outlet nozzle of the air-oil cooler 1 and returns to the lubricating oil tank through the pipeline for reuse. Temperature sensor 5, installed at the front end of the hot-side lubricating oil inlet nozzle of air-oil radiator 1, monitors the lubricating oil inlet temperature and feeds the temperature signal back to control box 6. Control box 6 calculates the required cold-side air inlet airflow of air-oil radiator 1 to achieve the desired lubricating oil temperature (i.e., calculates the cold-side airflow from the lubricating oil temperature change using the heat exchange power of air-oil radiator 1, and then calculates the rotational speed of electric axial fan 2 from the airflow), outputs a speed control signal for electric axial fan 2, controls the operating speed of electric axial fan 2, and thus controls the airflow, so that it meets the lubricating oil cooling requirements while reducing the machine's power consumption. The temperature and pressure sensing valve 3 connects the hot-side lubricating oil inlet pipe and the hot-side lubricating oil outlet pipe of the air-oil radiator 1. Under normal operating conditions, the valve is closed. When the heat dissipation core of the air-oil radiator 1 becomes blocked or the lubricating oil temperature is low and cooling by the air-oil radiator 1 is not required, the temperature and pressure sensing valve 3 opens, allowing the lubricating oil to bypass the air-oil radiator 1 and flow directly to the oil tank, reducing on-machine energy consumption and improving the reliability of the lubricating oil cooling system. The lubricating oil cooling device of this invention features low energy consumption, a wide range of applicable operating conditions, and high reliability.

[0042] The air-oil radiator 1 in the helicopter lubricating oil cooling system adopts a plate-fin cooling structure as its entire heat dissipation core. The temperature-sensing high-pressure valve 3 uses a shape memory alloy (temperature sensing element) + spring structure (pressure sensing element), where the spring structure is coaxial with the shape memory alloy. The electrically driven axial fan 2 adopts a "moving blade + guide vane" aerodynamic structure and is driven by an 800VDC high-voltage DC motor. The guide vane can rectify the rotating airflow at the moving blade outlet into axial flow, improving energy conversion efficiency and reducing flow loss. Tests have shown that the guide vane can reduce energy loss by 15% to 20% and improve fan efficiency by 5% to 8%. The internal motor and controller of the electrically driven axial fan 2 adopt a dual-redundancy design to improve system reliability. To reduce the structural weight of the system, the air-oil radiator 1 and the temperature and pressure sensing valve 3 are integrated into one unit. The temperature and pressure sensing valve 3 is directly connected to the hot-side lubricating oil inlet and outlet nozzles of the air-oil radiator 1 via threads. The temperature sensor 5 is installed at the front end of the hot-side lubricating oil inlet nozzle of the air-oil radiator 1. The air-oil radiator 1 and the transition air duct 4 are fixedly connected by bolts. The electric-driven axial fan 2 is installed on the other side of the transition air duct 4 via bolts. The control box 6 and the controller of the electric-driven axial fan 2 are integrated into one unit inside the electric-driven axial fan 2 and connected to the motor of the electric-driven axial fan 2 via bolts.

[0043] The above description is only a preferred embodiment of the present invention and does not limit the scope of protection of the present invention. All equivalent structural transformations made under the concept of the present invention using the description and drawings of the present invention, or direct / indirect applications in other related technical fields, are included within the scope of protection of the present invention.

Claims

1. A helicopter lubricating oil cooling device, characterized in that, include: An air-oil radiator (1) includes a cold-side air inlet, a cold-side air outlet, a hot-side oil inlet, and a hot-side oil outlet; An electrically driven axial fan (2) is connected to the cold side air outlet of an air-oil radiator (1) on its intake side. The temperature and pressure sensing valve (3) includes a first cavity, a second cavity, a temperature sensing element, a pressure sensing element, and a valve. The first cavity is provided with a first lubricating oil inlet and a first lubricating oil outlet. The second cavity is provided with a second lubricating oil inlet and a second lubricating oil outlet. The first lubricating oil inlet is connected to the hot-side lubricating oil outlet, and the second lubricating oil outlet is connected to the hot-side lubricating oil inlet. The temperature sensing element and the pressure sensing element are connected to the valve. The valve is normally open and is located between the first cavity and the second cavity to keep the two cavities connected. When the temperature sensing element is activated, the valve is closed. When the valve is closed and the pressure sensing element is activated, the valve is opened. Temperature sensor (5), the temperature sensor (5) is located upstream of the temperature and pressure valve (3) and the air-oil radiator (1) to measure the temperature of the lubricating oil before it enters the temperature and pressure valve (3) and the air-oil radiator (1); The control box (6) receives electrical signals from the temperature sensor (5) and outputs electrical signals to the electrically driven axial fan (2).

2. The helicopter lubricating oil cooling device according to claim 1, characterized in that: The temperature and pressure sensing valve (3) is integrated into the hot-side lubricating oil inlet end cap of the air-oil radiator (1).

3. The helicopter lubricating oil cooling device according to claim 1, characterized in that: The second lubricating oil inlet and the first lubricating oil outlet of the temperature and pressure sensing valve (3) are respectively connected to the hot-side lubricating oil inlet nozzle and the hot-side lubricating oil outlet nozzle of the air-lubricating oil radiator (1) by threads.

4. The helicopter lubricating oil cooling device according to claim 1, characterized in that: The air intake end of the electric axial fan (2) is connected to the cold side air outlet of the air-oil radiator (1) via the transition air duct (4). The transition air duct (4) is a variable cross-section shell with open ends and closed circumferentially. The air intake end and exhaust end of the transition air duct (4) are respectively connected to the cold side air outlet of the air-oil radiator (1) and the air intake end of the electric axial fan (2).

5. The helicopter lubricating oil cooling device according to claim 1, characterized in that: The control box (6) and the controller of the electric axial fan (2) are integrated into the electric axial fan (2) and connected to the motor of the electric axial fan (2). The electric axial fan (2) includes moving blades and guide blades, and the moving blades are located between the guide blades and the cold side air outlet of the air-oil radiator (1).

6. The helicopter lubricating oil cooling device according to claim 1, characterized in that: The motor of the electric axial fan (2) is a high-voltage DC motor, and the motor and controller of the electric axial fan (2) adopt a dual-redundancy design.

7. A method for cooling helicopter lubricating oil based on the helicopter lubricating oil cooling device according to claim 1, characterized in that, An air-cooled heat sink is used, and the following steps are included: S1, measure the lubricating oil temperature T1 before entering the air-cooled radiator. If T1 is higher than the normal working oil temperature range of the lubricating oil in the lubricating oil system, execute S2. If T1 falls within the normal working oil temperature range of the lubricating oil in the lubricating oil system, execute S3. S2, lubricating oil at temperature T1 is introduced into the hot-side lubricating oil inlet of the air-cooled radiator, and the lubricating oil is cooled by the air-cooled radiator. A fan is installed at the cold-side air outlet of the air-cooled radiator. The air intake volume of the cold-side air inlet of the air-cooled radiator is calculated based on the lubricating oil temperature T1 measured in S1, and the air intake volume is converted into the fan speed. By controlling the fan speed, air that meets the air intake volume requirements is supplied to the cold-side air inlet of the air-cooled radiator. S3, which bypasses the air-cooled radiator and outputs lubricating oil directly to the lubricating oil tank for later use.

8. The helicopter lubricating oil cooling method according to claim 7, characterized in that: In S1, a temperature-sensing valve connected to the hot-side lubricating oil inlet and hot-side lubricating oil outlet of the air-cooled radiator is used to control the flow direction of the lubricating oil. When T1 is higher than the operating temperature of the temperature-sensing element of the temperature-sensing valve, the temperature-sensing valve closes and S2 is executed. When T1 is lower than the operating temperature of the temperature-sensing element of the temperature-sensing valve, the temperature-sensing valve opens and S3 is executed.

9. The helicopter lubricating oil cooling method according to claim 7, characterized in that: In S2, the fan is a DC-driven axial fan.

10. The helicopter lubricating oil cooling method according to claim 7, characterized in that: S2 also includes measuring the lubricating oil pressure at the hot-side lubricating oil inlet of the air-cooled radiator. When the lubricating oil pressure is greater than the set value, S3 is executed.

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