Local forced cooling system of air-cooled rotor engine

Abstract

The utility model provides a local forced cooling system of an air-cooled rotor engine, and belongs to the technical field of cooling systems. The forced cooling device comprises a forced cooler which is communicated with an external cooling device, is arranged near a spark plug hole of the rotor engine and is used for cooling a cylinder body near the spark plug hole; the forced cooler is made of a light-weight high-heat-conduction material and is of a cooling flow channel topological structure for increasing the contact area of a cooling medium and a high-temperature cylinder body. The cooling runner topological configuration capable of increasing the contact area of the cooling medium and the high-temperature cylinder body is arranged near the spark plug hole of the rotor engine, and a local high-temperature area on the cylinder body is forcibly cooled, so that on one hand, the cooling effect better than that of full air cooling can be obtained; on the other hand, the forced cooler is made of a light-weight high-heat-conduction material, so that the weight is not increased much; compared with a liquid-cooled rotor engine, a high power-to-weight ratio close to that of an air-cooled rotor engine can be obtained.

Description

Technical Field

[0001] This utility model relates to the field of cooling system technology, and in particular to a local forced cooling system for an air-cooled rotary engine. Background Technology

[0002] With its excellent power-to-weight ratio, simple structure, compact size, low vibration, and outstanding high-speed performance, the aircraft rotary engine has become an ideal power solution for small and medium-sized unmanned aerial vehicles.

[0003] Two common cooling mechanisms are used in aircraft rotary engines: (1) liquid cooling, which uses coolant to circulate inside the engine to absorb the heat generated by combustion, and then the heat is transferred to the radiator and finally carried away by the air. This technology is particularly common in high-performance aircraft engines. The advantages of liquid cooling are its efficient heat dissipation performance and stable temperature control. However, it requires components such as water pumps and radiators, which increases the weight of the liquid cooling system and thus has an adverse effect on the power-to-weight ratio of the whole engine; (2) air cooling, which removes the heat generated by combustion by air flowing through the engine cooling fins. Its main advantages are its simple structure and light weight, and it does not require additional coolant. However, its heat dissipation efficiency is relatively low and the cooling effect is not satisfactory.

[0004] Because the spark plugs in a rotary engine are in a fixed position, the combustion temperature near the spark plug is higher after ignition and combustion, resulting in a significantly higher local temperature in that area of ​​the cylinder block compared to other parts. Especially under high-speed and high-load operating conditions, this can easily accelerate cylinder block wear and even cause problems such as coating cracking. Utility Model Content

[0005] In view of this, in order to solve the technical problem of excessive local temperature in the cylinder block near the spark plug of an aero-rotor engine, this utility model provides a local forced cooling system for an air-cooled rotary engine. By setting a cooling flow channel topology near the spark plug hole of the rotary engine to increase the contact area between the cooling medium and the high-temperature cylinder block, the local high-temperature area on the cylinder block is forcibly cooled. On the one hand, it can not only achieve a better cooling effect than a fully air-cooled engine; on the other hand, the forced cooler uses lightweight, high thermal conductivity materials, so the weight increase is minimal. Compared with a liquid-cooled rotary engine, it can achieve a power-to-weight ratio close to that of an air-cooled rotary engine.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A localized forced cooling system for an air-cooled rotary engine, comprising:

[0008] A forced cooler, connected to an external cooling system, is located near the spark plug holes of a rotary engine and is used to cool the cylinder block near the spark plug holes.

[0009] The forced cooler is made of lightweight, high thermal conductivity material, and the forced cooler has a cooling channel topology that increases the contact area between the cooling medium and the high-temperature cylinder block.

[0010] Preferably, the external cooling device includes:

[0011] A storage tank for storing the cooling medium is connected to the forced cooler via a cooling circulation pipeline and a pressurization pump.

[0012] Preferably, it further includes:

[0013] A radiator is connected to the cooling circulation pipe and is located between the outlet of the forced cooler and the storage tank.

[0014] Preferably, the radiator is provided with a cooling device for reducing the temperature of the cooling medium.

[0015] Preferably, it further includes:

[0016] A temperature control device is used to monitor the temperature of the cylinder block near the spark plug hole and control the local forced cooling system of the air-cooled rotary engine to cool down the cylinder block near the spark plug hole.

[0017] Preferably, the temperature control device includes:

[0018] A cylinder block temperature sensor is installed on the cylinder block near the spark plug hole to monitor the cylinder block temperature near the spark plug hole in real time.

[0019] The temperature control system receives the temperature signal transmitted by the cylinder temperature sensor and controls the start and stop of the pressurization pump.

[0020] Preferably, the temperature control system is a temperature controller.

[0021] Preferably, the temperature control device includes:

[0022] A cylinder block temperature sensor is installed on the cylinder block near the spark plug hole to monitor the cylinder block temperature near the spark plug hole in real time.

[0023] The electronic control unit receives the temperature signal transmitted by the cylinder temperature sensor and controls the start and stop of the pressurization pump.

[0024] Preferably, the cooling channel topology includes at least one of solenoid and spiral types, and may also be different pipe configurations such as straight pipe.

[0025] This utility model has the following advantages over the prior art:

[0026] This invention provides a localized forced cooling system for an air-cooled rotary engine, featuring a specific cooling channel structure designed around the spark plug bore. This structure significantly increases the contact area between the cooling medium and the high-temperature cylinder block surface, effectively performing forced cooling on localized high-temperature areas of the cylinder block. This method not only achieves better cooling efficiency than traditional all-air-cooled systems, but also effectively controls weight gain due to the use of lightweight materials with excellent thermal conductivity in the forced cooler. Compared to liquid-cooled rotary engines, this invention's air-cooled rotary engine achieves a power-to-weight ratio approaching that of liquid-cooled rotary engines, while also possessing the advantages of liquid-cooled systems in terms of cooling efficiency. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the present invention applied to an air-cooled rotary engine;

[0028] Figure 2 This is an assembly drawing of the present invention mounted on an air-cooled rotary engine;

[0029] Figure 3 This is a schematic diagram of a solenoid structure;

[0030] Figure 4 This is a schematic diagram of a spiral tube structure;

[0031] Figure 5 The effect of different internal flow channel topologies of different forced coolers on cylinder block cooling performance;

[0032] In the diagram, 1 is the rotary engine, 2 is the forced cooler, 3 is the spark plug, 4 is the cylinder block temperature sensor, 5 is the radiator, 6 is the pressure pump, 7 is the thermostat, and 8 is the storage tank. Detailed Implementation

[0033] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present utility model without creative effort are within the protection scope of the present utility model.

[0034] In the description of this utility model, it should be noted that the terms "upper", "lower", "inner", "outer", "top / bottom", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0035] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installed," "equipped with," "sleeved / connected," "connected," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0036] like Figure 1 As shown, a local forced cooling system for an air-cooled rotary engine 1 includes:

[0037] Forced cooler 2, connected to an external cooling device, is located near the spark plug 3 hole of rotary engine 1 and is used to cool the cylinder block near the spark plug 3 hole.

[0038] The forced cooler 2 is made of lightweight, high thermal conductivity material, and the forced cooler 2 has a cooling channel topology that increases the contact area between the cooling medium and the high-temperature cylinder block.

[0039] The forced cooler 2 is preferably fixed near the spark plug 3 hole of the rotary engine 1 by means of screw installation or casting, and is tightly fitted to the cylinder block; by designing cooling pipes of different shapes and sizes (cooling flow channel topology) inside, a cooling medium of a certain pressure flows through the cooling pipes to remove the cylinder block heat near the spark plug 3 hole, thereby reducing the cylinder block temperature.

[0040] The advantages of the forced cooler 2 involved in this utility model are mainly reflected in the following aspects:

[0041] First, its installation method is flexible and diverse. It can be fixed near the spark plug 3 hole of the rotary engine 1 by means of screw installation or casting, so as to ensure a tight fit with the cylinder block and thus improve cooling efficiency.

[0042] Secondly, the forced cooler 2 is designed with cooling pipes of different shapes and sizes (cooling flow channel topology) to increase the contact area or flow path between the cooling medium and the cylinder block, and extend the flow time of the cooling medium. It can make full use of the flow characteristics of the cooling medium, ensuring that the cooling medium can flow through the cooling pipes evenly and efficiently, effectively removing the cylinder block heat near the spark plug hole 3, and significantly reducing the temperature of the cylinder block (such as the spiral pipe shape promoting fluid turbulence and improving heat exchange efficiency).

[0043] Furthermore, by precisely controlling the pressure and flow rate of the cooling medium, the cooling effect of the forced cooler 2 can be further optimized, ensuring that the engine can still maintain stable operation under high temperature and high load conditions, and extending the service life of the engine.

[0044] In this invention, the external cooling device includes:

[0045] Storage tank 8 is used to store cooling medium and is connected to the forced cooler 2 through cooling circulation pipeline and pressurization pump 6.

[0046] The storage tank 8 is designed to efficiently store the cooling medium, ensuring a continuous and stable supply of cooling medium within the forced cooler 2. Through the connection between the cooling circulation pipeline and the booster pump 6, the storage tank 8 can respond quickly, delivering the cooling medium to the areas requiring cooling, achieving rapid and effective temperature control. Furthermore, the storage tank 8 has a rational structural design, capable of withstanding certain pressure and temperature fluctuations, ensuring the stable operation and safety of the system.

[0047] The booster pump 6 can be started by the temperature control device described below, or its start-up and regulation functions can be achieved by mechanical drive, electronic control, or other control methods. The pressure of the booster pump 6 can be kept constant, or the pump end pressure can be adjusted by changing the speed, etc.

[0048] This utility model also includes:

[0049] The radiator 5 is connected to the cooling circulation pipeline and is located between the outlet of the forced cooler 2 and the storage tank 8. It uses air convection to remove the heat of the cooling medium and cool it down.

[0050] In this invention, a cooling device, such as a cooling fan, can also be installed on the radiator 5 to reduce the temperature of the cooling medium. The fan's on / off state and speed are controlled by the temperature control device described below to achieve forced air cooling.

[0051] The design advantages of Radiator 5 and its fan are mainly reflected in the following aspects:

[0052] First, by installing a radiator 5 on the cooling circulation pipeline and placing it between the outlet of the forced cooler 2 and the storage tank 8, the principle of air convection is effectively utilized to remove heat from the cooling medium, achieving natural cooling of the cooling medium. This method not only improves heat dissipation efficiency but also reduces energy consumption, as natural convection does not require additional energy consumption.

[0053] Secondly, this invention can also incorporate a fan on the radiator 5 to further enhance heat dissipation. The fan's on / off state and speed can be precisely controlled by a temperature control device, thereby adjusting the heat dissipation intensity according to actual needs. This design allows this invention to adapt to different working environments and heat dissipation requirements, improving the flexibility and applicability of the equipment.

[0054] In summary, this utility model improves the heat dissipation efficiency of the cooling medium, reduces energy consumption, and enhances the flexibility and applicability of the equipment by optimizing the heat dissipation structure, thus exhibiting significant advantages.

[0055] This utility model also includes:

[0056] A temperature control device is used to monitor the temperature of the cylinder block near the spark plug hole 3 and control the local forced cooling system of the air-cooled rotary engine 1 to cool down the cylinder block near the spark plug hole 3.

[0057] In this utility model, one specific embodiment of the temperature control device includes:

[0058] Cylinder block temperature sensor 4 is installed on the cylinder block near the spark plug hole 3 to monitor the temperature of the cylinder block near the spark plug hole in real time;

[0059] The temperature control system receives the temperature signal transmitted by the cylinder temperature sensor 4 and controls the start and stop of the pressure pump 6.

[0060] In this invention, the temperature control system is a temperature controller 7.

[0061] In this utility model, another specific embodiment of the temperature control device includes:

[0062] Cylinder block temperature sensor 4 is installed on the cylinder block near the spark plug hole 3 to monitor the temperature of the cylinder block near the spark plug hole in real time;

[0063] The electronic control unit receives the temperature signal transmitted by the cylinder temperature sensor 4 and controls the start and stop of the pressurization pump 6.

[0064] The main advantages of this utility model with a temperature control device are:

[0065] The temperature control device allows for real-time monitoring of the cylinder block temperature near the spark plug hole 3. This function is crucial for ensuring stable engine operation, as excessively high temperatures can lead to accelerated cylinder block wear or even damage.

[0066] The temperature control device can control the local forced cooling system of the air-cooled rotary engine 1 to cool the cylinder block near the spark plug 3 holes. This local cooling method is more efficient than overall cooling and can quickly reduce the temperature of critical areas, preventing overheating.

[0067] The temperature control device can be implemented in various ways. It can use a temperature controller 7 as the temperature control system for simple and reliable temperature control; or it can receive temperature signals and control the start and stop of the pressure pump 6 through an electronic control unit to achieve more precise and intelligent temperature regulation. This versatility allows this invention to adapt to different application scenarios and needs.

[0068] like Figure 2-4 As shown, in this invention, the cooling channel topology is at least one of a solenoid and a spiral, and also includes other pipe configurations such as a straight pipe. Specifically, the straight pipe configuration employs a neural-morphological topological fractal channel (the channel exhibits a "nerve-like" or "tree root-like" branching structure, integrating neural network optimization design, biomimetic fractal structure, and topology optimization technology into parallel straight channels based on heat flow distribution and flow resistance). The inner layer of the pipe wall uses a high thermal conductivity alloy or a high thermal conductivity composite coating to enhance boundary layer heat transfer. The solenoid configuration is based on the straight pipe configuration, with the pipe exhibiting a spiral bending change extending along its length. The spiral pipe configuration is generally circular or square, structurally exhibiting a spatial spiral, with a smooth inner wall to reduce fluid resistance. The pipe diameter range, number of spiral turns, shape, and length can be varied to adapt to different cooling requirements. This cooling channel topology significantly increases the contact area, flow path, and flow time between the cooling medium and the cylinder, significantly improving the cooling effect.

[0069] In this invention, the cooling medium includes liquid fuels such as aviation kerosene, gasoline, diesel, alcohols or liquid hydrogen, or non-fuel media such as cooling water and refrigerant.

[0070] The working principle of this utility model is as follows:

[0071] After the rotary engine 1 has been running for a certain period of time, the cylinder block temperature gradually increases due to the heat transfer from the high-temperature combustion gases inside the cylinder. A temperature sensor is installed on the cylinder block near the spark plug 3 to measure the cylinder block temperature. When the cylinder block temperature measured by the temperature sensor exceeds a certain value, the thermostat 7 connected to the temperature sensor controls the start-up of the pressurization pump 6. After the pressurization pump 6 starts running, the coolant stored in the storage tank 8 is drawn out and pressurized by the pressurization pump 6 (the pump outlet pressure can be adjusted by an electrical signal), and then delivered to the cooling pipes of the forced cooler 2. The coolant flows through the cooling pipes in the forced cooler 2, carrying away the heat from the cylinder block and reducing the temperature of the high-temperature areas of the cylinder block. The coolant flowing out of the forced cooler 2 has an increased temperature and flows into the radiator 5; the coolant after being cooled by the radiator 5 finally flows back into the storage tank 8.

[0072] The technical solution of this utility model will be clearly and thoroughly described below with reference to specific embodiments.

[0073] Example 1

[0074] Temperature control system selects temperature controller 7

[0075] The specific process of the above method will be explained in detail using a carburetor-type (non-electronically controlled) rotary engine 1 as an example:

[0076] After the rotary engine 1 starts, the cylinder block temperature rises rapidly as the engine speed increases. When the cylinder block temperature sensor 4 detects that the cylinder block temperature exceeds 120°C, the connected thermostat 7 controls the power supply to the booster pump 6. After the booster pump 6 is powered on, the cooling medium (such as cooling water) stored in the storage tank 8 is drawn out, pressurized to 0.15 MPa by the booster pump 6, and then delivered to the cooling pipes of the forced cooler 2. The cooling pipes can adopt different layout schemes, including but not limited to straight pipes, helical pipes, spiral pipes, etc., and the pipe size is determined according to the specific cooling requirements and the pressure of the booster pump 6. After the cooling water flows through the cooling pipes at a pressure of 0.15 MPa, it carries away the heat from the cylinder block and reduces the temperature of its high-temperature areas. The cooling effect is as follows: Figure 5 As shown, when the rotary engine 1 operates under rated conditions for an extended period, the maximum cylinder temperature using a fully air-cooled structure approaches 240°C. However, with the forced cooler 2, the maximum cylinder temperature is significantly reduced. Using a straight-pipe configuration, the maximum cylinder temperature can be reduced to 200°C; with a helical-pipe configuration, it drops to 197°C; and with a spiral-pipe configuration, the maximum cylinder temperature can be further reduced to 196°C and 192°C for different pipe diameters. Compared to the fully air-cooled rotary engine 1, the reduction in maximum cylinder temperature using different cooler configurations can reach 16.1% to 19.3%, demonstrating a significant improvement in cooling performance.

[0077] After the cylinder block temperature is reduced, the cooling water flowing out of the forced cooler 2 becomes hotter and flows into the radiator 5. If the rotary engine 1 is installed on fast-moving equipment (such as a drone), it can dissipate heat through the high-speed airflow generated by the drone's flight, thereby reducing the cooling water temperature, and finally flow back into the storage tank 8. If the rotary engine 1 is stationary and there is no high-speed airflow to cool the radiator 5, a fan can be installed on the radiator 5, and the fan speed can be synchronously controlled by the temperature controller 7 to reduce the cooling water temperature.

[0078] When the cylinder block temperature sensor 4 detects that the cylinder block temperature is lower than a certain temperature (such as 100°C), for example, when the rotary engine 1 is running at low speed and the cylinder block temperature is low, in order to reduce heat loss, the temperature controller 7 connected to it cuts off the power to the booster pump 6, that is, it shuts off the booster pump 6 and does not cool the cylinder block through the forced cooler 2.

[0079] Example 2

[0080] The temperature control system in the temperature control device is selected from electronic control units.

[0081] If the rotary engine 1 uses an electronic control unit (ECU) to control the fuel injection system, ignition system, and booster pump 6, the thermostat 7 can be eliminated. The ECU directly receives the temperature signal from the cylinder block temperature sensor 4 and then determines whether to activate the booster pump 6 based on the parameters set within the ECU software. When the temperature sensor detects that the cylinder block temperature is higher than a certain temperature, the ECU directly activates the booster pump 6 and controls the booster pump 6 to change the pump outlet pressure (e.g., within a range of 0.15MPa-0.5MPa), thereby adjusting the flow rate of the cooling medium to improve the heat dissipation effect of the forced radiator 5. The ECU can also implement feedback control of cylinder block temperature via a temperature sensor (i.e., turning the booster pump 6 on or off within a certain temperature range; for example, turning on the booster pump 6 when the cylinder block temperature exceeds 120°C and turning it off when the cylinder block temperature is below 100°C). The cooling medium flowing out of the forced cooler 2 further flows into the radiator 5, and the medium cooled by the radiator 5 finally flows back into the storage tank 8. An electric fan is installed on the radiator 5, and the ECU directly controls the fan speed to reduce the temperature of the cooling medium returning to the storage tank 8.

[0082] The above are merely preferred embodiments of this utility model; however, the scope of protection of this utility model is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in this utility model, based on the technical solution and its improved concept, should be included within the scope of protection of this utility model.

Claims

1. A localized forced cooling system for an air-cooled rotary engine, characterized in that, include: A forced cooler, connected to an external cooling system, is located near the spark plug holes of a rotary engine and is used to cool the cylinder block near the spark plug holes. The forced cooler is made of lightweight, high thermal conductivity material, and the forced cooler has a cooling channel topology that increases the contact area between the cooling medium and the high-temperature cylinder block.

2. The local forced cooling system for an air-cooled rotary engine according to claim 1, characterized in that, The external cooling device includes: A storage tank for storing the cooling medium is connected to the forced cooler via a cooling circulation pipeline and a pressurization pump.

3. The local forced cooling system for an air-cooled rotary engine according to claim 2, characterized in that, Also includes: A radiator is connected to the cooling circulation pipe and is located between the outlet of the forced cooler and the storage tank.

4. The local forced cooling system for an air-cooled rotary engine according to claim 3, characterized in that, The radiator is equipped with a cooling device to reduce the temperature of the cooling medium.

5. A local forced cooling system for an air-cooled rotary engine according to claim 2, characterized in that, Also includes: A temperature control device is used to monitor the temperature of the cylinder block near the spark plug hole and control the local forced cooling system of the air-cooled rotary engine to cool down the cylinder block near the spark plug hole.

6. A local forced cooling system for an air-cooled rotary engine according to claim 5, characterized in that, The temperature control device includes: A cylinder block temperature sensor is installed on the cylinder block near the spark plug hole to monitor the cylinder block temperature near the spark plug hole in real time. The temperature control system receives the temperature signal transmitted by the cylinder temperature sensor and controls the start and stop of the pressurization pump.

7. A local forced cooling system for an air-cooled rotary engine according to claim 6, characterized in that, The temperature control system is a temperature controller.

8. A local forced cooling system for an air-cooled rotary engine according to claim 5, characterized in that, The temperature control device includes: A cylinder block temperature sensor is installed on the cylinder block near the spark plug hole to monitor the cylinder block temperature near the spark plug hole in real time. The electronic control unit receives the temperature signal transmitted by the cylinder temperature sensor and controls the start and stop of the pressurization pump.

9. A local forced cooling system for an air-cooled rotary engine according to any one of claims 1-8, characterized in that, The cooling channel topology includes at least one of the following: straight tube type, solenoid type, and spiral tube type.

Images