Method for realizing full heavy fuel flight of piston engine driven UAV

Abstract

A method for realizing full heavy oil flight of a piston engine driven unmanned aerial vehicle, wherein the piston engine is a carburetor engine, a thermal management system is configured on the piston engine, a heating block is fixedly connected to the oil chamber of the carburetor, kerosene is added to the heavy oil tank and gasoline is added to the small oil tank when the engine of the unmanned aerial vehicle is not started on the ground; the engine is started, and the gasoline enters the carburetor through the oil pump and is sucked into the engine to start the engine, and after the engine is started, as the gasoline is pumped away, the kerosene in the heavy oil tank flows into the small oil tank under the action of pressure, and when black smoke begins to emerge from the exhaust pipe of the engine, the heating block is heated by an electric heating rod, and the heavy oil in the carburetor is drained through the oil drain switch at the next takeoff, the small oil tank is removed, and a small oil tank filled with gasoline is replaced. The present invention can meet the condition of using heavy oil as fuel during flight.

Description

Technical Field

[0001] The invention relates to an unmanned aerial vehicle, in particular to a method for realizing full heavy fuel flight of an unmanned aerial vehicle driven by a piston engine, and belongs to the field of aviation technology. Background Art

[0002] Because piston engines have many advantages such as small size, light weight, high power per liter, simple structure, and convenient operation and maintenance, the current small and medium-sized payload drones still mainly choose piston engines as driving power. However, the current piston engines are basically fueled by gasoline. Because of the adverse consequences that gasoline may have in a crash, gasoline as fuel limits the application of drones in certain occasions, such as forest fire prevention, mission execution in densely populated areas, etc. Heavy oil engines have obvious advantages over gasoline in terms of safety, but it is well known in the industry that heavy oil has high viscosity and is difficult to atomize. Using pure heavy oil as fuel during flight requires a major transformation of the engine system. The progress of this type of engine is described in detail in the Internet document "Progress in Heavy Oil Technology for Small Power Aviation Piston Engines". The cost of this transformation is very high, so it also leads to high costs for engines fueled by heavy oil. For example, a 170cc electronic injection heavy oil engine sold by a domestic company is priced at nearly 300,000 yuan. Such a high price seriously hinders the application of heavy oil engines in drones, and is not conducive to the development of heavy oil engine technology itself, making it difficult for drones to meet the requirements of using heavy oil as fuel during flight. Summary of the invention

[0003] The purpose of the present invention is to overcome the above-mentioned problem that current UAVs use heavy oil as fuel during flight, and to provide a method for a piston engine-driven UAV to achieve full heavy oil flight.

[0004] To achieve the purpose of the present invention, the following technical scheme is adopted: a method for a piston engine driven unmanned aerial vehicle to achieve full heavy fuel flight, the piston engine is a carburetor engine, the carburetor is connected to the fuel supply system, the piston engine is equipped with a thermal management system, the thermal management system includes a water cooling jacket fixedly connected to the engine cylinder, the water cooling jacket has an inlet and an outlet for coolant, the inlet and the outlet are respectively connected to a heat sink through a circulating water circuit, a circulating pump is installed on the circulating water circuit, a heat sink fan is installed on the upper part of the heat sink, the air outlet direction of the heat sink blows toward the heat sink, the heat sink is installed on the frame below the rotor, the fuel supply system includes a heavy fuel tank, an oil pump, and a small oil tank, the small oil tank is a sealed tank, the inlet end of pipeline A is located in the small oil tank near the bottom, and the outlet end is directly or indirectly connected to the inlet of the oil pump, the inlet end of pipeline B is located in the heavy fuel tank near the bottom, and the outlet end is located in the small oil tank near the upper mouth, and the outlet of the oil pump is connected to the carburetor through an oil outlet pipe;

[0005] A heating block is fixedly connected to the oil chamber of the carburetor, and at least two holes are opened on the heating block, in which a temperature control switch A is fixedly set, and an electric heating rod is installed in the other hole, the electric heating rod is connected to a heating power supply, and the temperature control switch A is connected to the heating power supply circuit of the electric heating rod, the upper end of the heating block passes through the bottom surface of the carburetor, the heating block is located below the main metering hole of the carburetor, the heating block is in contact with the oil in the carburetor, an oil drain pipeline communicating with the oil chamber is opened on the bottom surface of the carburetor or the heating block, and an oil drain switch is installed on the oil drain hole;

[0006] A temperature control switch B is installed on the heat dissipation water tank, and the temperature control switch B is connected to the power supply circuit of the heat dissipation fan. A temperature control switch C is installed on the cooling jacket, and the temperature control switch C is connected to the power supply circuit of the circulation pump. The heat dissipation fan is rectangular, and four fixing columns are fixedly arranged around the heat dissipation fan. A wind shield is fixedly installed on the upper end of the fixing column, and the wind shield covers the entire heat dissipation fan area. There is a gap between the wind shield and the upper surface of the heat dissipation fan.

[0007] The drone can be fully fueled by the following methods:

[0008] A: Temperature control switch A temperature T1 setting, set T1 temperature to a value between 80-90℃, when it exceeds T1, temperature control switch A is disconnected, when it is lower than T1, temperature control switch A is closed, and the electric heating rod is heated when temperature control switch A is closed; Temperature control switch B temperature T2 setting, set T2 temperature to a value between 75-85℃, when it exceeds T2, temperature control switch B is closed, when it is lower than T2, temperature control switch B is disconnected, and the cooling fan is operated when temperature control switch B is closed; Temperature control switch C temperature T3 setting, set T3 temperature to a value between 68-74℃, when it exceeds T3, temperature control switch C is closed, when it is lower than T3, temperature control switch C is disconnected, and temperature control switch T3 is closed and the circulation pump is operated;

[0009] B: When the UAV is on the ground and the engine is not started, add kerosene to the heavy fuel tank and gasoline to the small fuel tank;

[0010] C: Start the engine. Gasoline enters the carburetor through the oil pump and is sucked into the engine to start the engine. After the engine starts, it generates heat, which increases the temperature of the engine itself.

[0011] D: After the engine is started, as the gasoline is pumped away, the kerosene in the heavy oil tank flows into the small oil tank under the action of pressure, and the fuel entering the carburetor gradually becomes a mixture of kerosene and gasoline;

[0012] E: When the exhaust pipe of the engine starts to emit black smoke, the heating block is heated by the electric heating rod, and the fuel before entering the engine is preheated to temperature T1 through the carburetor;

[0013] F: As the heavy oil enters the small oil tank, the fuel entering the carburetor gradually becomes full heavy oil, and the drone takes off; during the flight, each temperature control switch opens and closes according to the set temperature;

[0014] D: After completing the mission, the drone lands on the ground. When taking off next time, the heavy oil in the carburetor is drained through the oil drain switch, the small oil tank is removed, and replaced with a small oil tank filled with gasoline.

[0015] Furthermore, the amount of gasoline in the small oil tank must ensure that the engine can run without shutting down until the temperature control switch C is closed for the first time.

[0016] Furthermore, the small oil tank is screwed with an upper cover through a thread, and pipeline A and pipeline B are sealed and inserted on the upper cover.

[0017] The positive and beneficial technical effects of the present invention are: the present invention adopts conventional gasoline to start the engine, and the gasoline is gradually consumed when the engine is preheated after starting. During the preheating process, the fuel is heated by the carburetor, so that the kerosene entering the engine is very easy to atomize, which meets the combustion requirements of the engine. The present invention can realize the flight of the UAV without carrying gasoline (all heavy oil flight) through a not-too-complicated modification on the basis of the existing carburetor engine using gasoline as fuel, and can meet the condition of using heavy oil as fuel during the flight, expand the use space of the UAV, and create conditions for further research and development of heavy oil engines in applications. After calculation, its cost is less than one-tenth of the current heavy oil engine. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the fuel supply system.

[0019] Figure 2 This is a diagram of a carburetor.

[0020] Figure 3 is a schematic diagram of the thermal management system.

[0021] Figure 4 This is a schematic diagram of the radiator tank. DETAILED DESCRIPTION

[0022] In order to more fully explain the implementation of the present invention, implementation examples of the present invention are provided. These implementation examples are merely elaborations of the present invention and do not limit the scope of the present invention.

[0023] The marks in the attached drawings are: 1: heavy oil tank; 2: pipeline B; 3: small oil tank; 4: pipeline A; 5: oil filter element; 6: oil pump; 7: heating block; 8: carburetor; 9: oil chamber; 10: heating rod; 11: temperature control switch A; 12: oil drain pipeline; 13: oil drain switch; 14: engine; 15: cylinder; 16: water cooling jacket; 17: inlet; 18: outlet; 19: temperature control switch C; 20: cooling water tank; 21: temperature control switch B; 22: circulating pump; 23: wind shield; 24: cooling fan; 25: expansion tank; 26: fixing column.

[0024] A method for achieving full heavy fuel flight for a piston engine-driven UAV, the piston engine being a carburetor engine 14, the carburetor 8 being connected to a fuel supply system, the fuel supply system comprising a heavy fuel tank 1, an oil pump 6, and a small oil tank 3, the small oil tank being a sealed tank, the inlet end of a pipeline A4 being located in the small oil tank near the bottom, the outlet being connected to an oil filter element 5, the oil filter element being connected to the inlet of the oil pump 6, the inlet end of a pipeline B3 being located in the heavy fuel tank 1 near the bottom, the outlet end being located in the small oil tank 3 near the upper opening, the outlet end being located above the liquid surface of the small oil tank, and the outlet of the oil pump 6 being connected to the carburetor 8 via an oil outlet pipe.

[0025] A heating block 7 is fixedly connected to the oil chamber 9 of the carburetor 8, and at least two holes are opened on the heating block. A temperature control switch A11 is fixedly set in one of the holes, and an electric heating rod 12 is installed in the other hole. The electric heating rod is connected to a heating power supply, and the temperature control switch A11 is connected to the heating power supply circuit of the electric heating rod. The upper end of the heating block 7 passes through the bottom surface of the carburetor, and the heating block is located below the main metering hole of the carburetor. The heating block is in contact with the oil in the carburetor. An oil drain pipeline 12 communicating with the oil chamber is opened on the bottom surface of the carburetor or the heating block, and an oil drain switch 13 is installed on the oil drain hole. The oil drain switch can be a valve or a plug screwed on by a thread.

[0026] The piston engine is equipped with a thermal management system, which includes a water cooling jacket 16 fixedly connected to the engine cylinder, the water cooling jacket has an inlet 17 and an outlet 18 for coolant, the inlet and the outlet are respectively connected to a cooling water tank 20 through a circulating water circuit, a circulating pump 22 is installed on the circulating water circuit, a temperature control switch C19 is installed on the cooling jacket, the temperature control switch C19 is connected to the power supply circuit of the circulating pump, a temperature control switch B21 is installed on the cooling water tank, a cooling fan 24 is installed on the upper part of the cooling water tank, the temperature control switch B21 is connected to the power supply circuit of the cooling fan, the air outlet direction of the cooling fan blows toward the cooling water tank, the cooling water tank is installed on the frame under the rotor, and the installation method of the cooling water tank is as described by the applicant in Chinese patent application No. 201922228043.6 (Agricultural Plant Protection No. The installation method of the human-machine engine temperature controllable heat dissipation device) (the heat dissipation water tank in this application corresponds to the radiator in the patent), the heat dissipation water tank is connected to an expansion water tank 25, and the function and principle of the expansion water tank are the same as those of the expansion water tank in the current automobile. When the pressure in the heat dissipation water tank is high, the coolant enters the expansion water tank, and when the pressure in the heat dissipation water tank is low, the coolant enters the heat dissipation box. The heat dissipation fan is rectangular, and four fixed columns 26 are fixedly arranged around the heat dissipation fan. A windshield 23 is fixedly installed on the upper end of the fixed column. The windshield covers the entire heat dissipation fan area, and there is a gap between the windshield and the upper surface of the heat dissipation fan; the function of the windshield is to ensure that when flying at low temperatures, the airflow generated by the rotor will not blow onto the heat dissipation water tank to take away heat, so as to ensure that the engine has sufficient temperature to make the heavy oil burn well.

[0027] The drone can be fully fueled by the following methods:

[0028] A: Temperature control switch A is set to T1, and the temperature T1 is set to 80-90℃. If the temperature exceeds T1, the temperature control switch A is disconnected, and if it is lower than T1, the temperature control switch A is closed. When the temperature control switch A is closed, the electric heating rod is heated; Temperature control switch B is set to T2, and the temperature T2 is set to 75-85℃. If the temperature exceeds T2, the temperature control switch B is closed, and if it is lower than T2, the temperature control switch B is disconnected, and the cooling fan is operated when the temperature control switch B is closed; Temperature control switch C is set to T3, and the temperature T3 is set to 68-74℃. If the temperature exceeds T3, the temperature control switch C is closed, and if it is lower than T3, the temperature control switch A is disconnected, and the temperature control switch T3 is closed to operate the circulation pump;

[0029] B: When the UAV engine is not started on the ground, add kerosene to the heavy fuel tank and gasoline to the small oil tank; the amount of gasoline in the small oil tank should ensure that the engine can run without shutting down until the temperature control switch C is closed for the first time;

[0030] C: Start the engine. Gasoline enters the carburetor through the oil pump and is sucked into the engine to start the engine. After the engine starts, it generates heat, which increases the temperature of the engine itself.

[0031] D: After the engine is started, as the gasoline is pumped away, the kerosene in the heavy oil tank flows into the small oil tank under the action of pressure, and the fuel entering the carburetor gradually becomes a mixture of kerosene and gasoline;

[0032] E: When the exhaust pipe of the engine starts to emit black smoke, the electric heating rod starts to be heated, and the fuel before entering the engine is preheated to temperature T1 through the carburetor;

[0033] F: As the heavy oil enters the small oil tank, the fuel entering the carburetor gradually becomes full heavy oil, and the drone takes off; during the flight, each temperature control switch opens and closes according to the set temperature;

[0034] D: After completing the mission, the drone lands on the ground. When taking off next time, the heavy oil in the carburetor is drained through the oil drain switch, the small oil tank is removed, and replaced with a small oil tank filled with gasoline. Specific embodiment:

[0036] Based on a 210cc two-stroke twin-cylinder aircraft engine, the ambient temperature is 15°C, the engine itself is not heated, T1 is set to 80°C, T2 is set to 80°C, T3 is set to 70°C, the heavy fuel tank uses the current fuel tank, and the small oil tank uses an aluminum alloy medicine bottle purchased online. About 100ml of gasoline is filled in the aluminum alloy medicine bottle (later it was verified that heating 60ml of gasoline can also be done. In the early stage, more gasoline was added for safety reasons). The engine is equipped with a nibbi carburetor. The bottom of one type of carburetor itself has a screw hole with a plug. A heating block with an electric heating rod and a temperature control switch is installed in the screw hole. The gasoline in the small oil tank is input into the oil pump. After the carburetor is filled, the engine is started directly in the conventional way. The engine using gasoline is very easy to start as usual. After starting, as the gasoline in the small oil tank is pumped out, the heavy oil in the heavy oil tank automatically flows into the small oil tank under pressure and mixes with the gasoline. The fuel entering the carburetor changes from gasoline, a mixture of gasoline and heavy oil to heavy oil. When the exhaust pipe discharges black smoke, the heating power supply of the electric heating rod is turned on to heat the fuel. The heating constant temperature is 80℃, the engine runs smoothly, and the flameout will not occur. The drone is driven to fly smoothly. The thermal management system operates according to the set temperature during flight. This method has been tested at -20℃ and can be achieved.

[0037] After describing the implementation mode of the present invention in detail, people familiar with the technology can clearly understand that various changes and modifications can be made without departing from the scope and spirit of the above-mentioned patent application. Any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention belong to the scope of the technical solution of the present invention, and the present invention is not limited to the implementation mode of the examples given in the specification.

Claims

1. A method for realizing full heavy fuel flight of a piston engine driven UAV, wherein the piston engine is a carburetor engine, the carburetor is connected to a fuel supply system, and a thermal management system is configured on the piston engine, wherein the thermal management system comprises a water cooling jacket fixedly connected to the engine cylinder, the water cooling jacket has an inlet and an outlet for a coolant, the inlet and the outlet are respectively connected to a heat dissipation water tank through a circulating water circuit, a circulating pump is installed on the circulating water circuit, a heat dissipation fan is installed on the upper part of the heat dissipation water tank, the air outlet direction of the heat dissipation fan blows toward the heat dissipation water tank, and the heat dissipation water tank is installed on a frame below a rotor, and the characteristics are: The oil supply system includes a heavy oil tank, an oil pump, and a small oil tank. The small oil tank is a sealed tank. The inlet end of the pipeline A is located near the bottom of the small oil tank, and the outlet end is directly or indirectly connected to the inlet of the oil pump. The inlet end of the pipeline B is located near the bottom of the heavy oil tank, and the outlet end is located near the upper opening of the small oil tank. The outlet of the oil pump is connected to the carburetor through an oil outlet pipe. A heating block is fixedly connected to the oil chamber of the carburetor, and at least two holes are opened on the heating block, in which a temperature control switch A is fixedly set, and an electric heating rod is installed in the other hole, the electric heating rod is connected to a heating power supply, and the temperature control switch A is connected to the heating power supply circuit of the electric heating rod, the upper end of the heating block passes through the bottom surface of the carburetor, the heating block is located below the main metering hole of the carburetor, the heating block is in contact with the oil in the carburetor, an oil drain pipeline communicating with the oil chamber is opened on the bottom surface of the carburetor or the heating block, and an oil drain switch is installed on the oil drain hole; A temperature control switch B is installed on the heat dissipation water tank, and the temperature control switch B is connected to the power supply circuit of the heat dissipation fan. A temperature control switch C is installed on the cooling jacket, and the temperature control switch C is connected to the power supply circuit of the circulation pump. The heat dissipation fan is rectangular, and four fixing columns are fixedly arranged around the heat dissipation fan. A wind shield is fixedly installed on the upper end of the fixing column, and the wind shield covers the entire heat dissipation fan area. There is a gap between the wind shield and the upper surface of the heat dissipation fan. The drone can be fully fueled by the following methods: A: Temperature control switch A temperature T1 setting, set T1 temperature to a value between 80-90℃, when it exceeds T1, temperature control switch A is disconnected, when it is lower than T1, temperature control switch A is closed, and the electric heating rod is heated when temperature control switch A is closed; Temperature control switch B temperature T2 setting, set T2 temperature to a value between 75-85℃, when it exceeds T2, temperature control switch B is closed, when it is lower than T2, temperature control switch B is disconnected, and the cooling fan is operated when temperature control switch B is closed; Temperature control switch C temperature T3 setting, set T3 temperature to a value between 68-74℃, when it exceeds T3, temperature control switch C is closed, when it is lower than T3, temperature control switch C is disconnected, and temperature control switch T3 is closed and the circulation pump is operated; B: When the UAV is on the ground and the engine is not started, add kerosene to the heavy fuel tank and gasoline to the small fuel tank; C: Start the engine. Gasoline enters the carburetor through the oil pump and is sucked into the engine to start the engine. After the engine starts, it generates heat, which increases the temperature of the engine itself. D: After the engine is started, as the gasoline is pumped away, the kerosene in the heavy oil tank flows into the small oil tank under the action of pressure, and the fuel entering the carburetor gradually becomes a mixture of kerosene and gasoline; E: When the exhaust pipe of the engine starts to emit black smoke, the electric heating rod starts to be heated, and the fuel before entering the engine is preheated to temperature T1 through the carburetor; F: As the heavy oil enters the small oil tank, the fuel entering the carburetor gradually becomes full heavy oil, and the drone takes off; during the flight, each temperature control switch opens and closes according to the set temperature; D: After completing the mission, the drone lands on the ground. When taking off next time, the heavy oil in the carburetor is drained through the oil drain switch, the small oil tank is removed, and replaced with a small oil tank filled with gasoline.

2. The method for realizing full heavy fuel flight of a piston engine driven UAV according to claim 1, characterized in that: The amount of gasoline in the small oil tank is sufficient to ensure that the engine can run without being turned off until the temperature control switch C is closed for the first time.

3. The method for realizing full heavy fuel flight of a piston engine driven UAV according to claim 1, characterized in that: An upper cover is screwed onto the small oil tank through threads, and pipelines A and B are sealed and inserted into the upper cover.

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