Fuel supply system
The fuel supply system addresses ignition coil overheating by converting liquid fuel to gas for cooling, stabilizing ammonia combustion, and reducing failure risks, enabling efficient engine operation and compact vehicle design.
Patent Information
- Application Number
- JP2024191852
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2024-10-31
- Publication Date
- 2026-05-18
AI Technical Summary
Existing fuel supply systems lack an effective cooling mechanism for cooling targets such as ignition coils, which can lead to overheating and failure when high energy is supplied to spark plugs, especially in engines using fuels like ammonia that are difficult to burn.
A fuel supply system incorporating a cooling path with a tank, fuel supply path, and evaporator, where liquid fuel is converted to gas, cooled, and used to cool the ignition coil by evaporating and absorbing heat from airflow, with components like compressors and condensers arranged in sequence to manage fuel state changes.
The system efficiently cools the ignition coil, stabilizes fuel combustion, reduces the risk of ignition coil failure, and allows for compact vehicle design by using fuel as a refrigerant, ensuring reliable engine operation.
Smart Images
Figure 2026080227000001_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to a fuel supply system.
Background Art
[0002] As an invention related to a conventional fuel supply system, for example, a cooling structure of an ignition coil described in Patent Document 1 is known. This cooling structure of the ignition coil cools the ignition coil using the cooling water of an internal combustion engine.
Prior Art Documents
Patent Documents
[0003]
Patent Document 1
Summary of the Invention
Problems to be Solved by the Invention
[0004] As described above, a system capable of cooling a cooling target such as an ignition coil is required.
[0005] Therefore, an object of the present invention is to provide a fuel supply system capable of cooling a cooling target.
Means for Solving the Problems
[0006] The first aspect is that the fuel supply system includes a tank, a fuel supply path, a cooling path, and an evaporator, the tank stores fuel, the fuel supply path supplies the fuel in the tank to an injector, the injector injects the fuel supplied by the fuel supply path, the upstream end and the downstream end of the cooling path are connected to the tank, so that the fuel in the tank passes through the cooling path, The evaporator cools the fluid surrounding it by changing the liquid fuel in the cooling path into a gaseous fuel. The fluid cooled by the evaporator cools the cooling target of the vehicle to which the fuel supply system is applied. It is a fuel supply system.
[0007] The second aspect is, The engine of the aforementioned vehicle is equipped with an ignition device for burning the fuel injected by the injector, The ignition device includes an ignition coil, The object to be cooled is the ignition coil. This is the fuel supply system described on the first side.
[0008] The third aspect is, The fluid is air, The airflow generated by the vehicle moving forward strikes the evaporator, thereby cooling the air. The evaporator is located in front of the object to be cooled. This is the fuel supply system described on the second side.
[0009] The fourth aspect is, The fuel supply system further comprises a compressor and a condenser. The compressor, the condenser, and the evaporator are arranged in the cooling path in this order from upstream to downstream. The compressor pressurizes the fuel in the cooling path, The condenser supplies liquid fuel to the evaporator by cooling the fuel pressurized by the compressor. The fuel supply system is as described in any of the first, second, or third aspects.
[0010] The fifth aspect is, The aforementioned fuel is ammonia. It is the fuel supply system described in any of the first to fourth side surfaces.
Advantages of the Invention
[0011] According to the present invention, it is possible to cool a cooling target.
Brief Description of the Drawings
[0012] [Figure 1] FIG. 1 is a block diagram of the fuel supply system 1. [Figure 2] FIG. 2 is a cross-sectional view of the engine 10.
Embodiments for Carrying Out the Invention
[0013] (Embodiment) [Structure of the Fuel Supply System 1] The structure of the fuel supply system 1 according to an embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram of the fuel supply system 1. FIG. 2 is a cross-sectional view of the engine 10. In FIG. 2, the front-rear direction, left-right direction, and up-down direction of the vehicle are simply referred to as the front-rear direction, left-right direction, and up-down direction, respectively.
[0014] The fuel supply system 1 supplies fuel to the engine 10 of the vehicle. The vehicle is, for example, a four-wheel automobile. As shown in FIG. 1, the fuel supply system 1 includes a fuel supply path R1, a cooling path R2, a tank 30, a heater 32, injectors 34a to 34c, a pump 36, a heater 37, a compressor 38, a condenser 40, an expansion valve 42, an evaporator 44, and a compressor 46.
[0015] The tank 30 stores fuel in a liquid state. In the present embodiment, the fuel is ammonia. The fuel supply path R1 is a pipe for supplying the fuel in the tank 30 to the injectors 34a to 34c. Therefore, the fuel flows from the tank 30 through the fuel supply path R1 to the injectors 34a to 34c. Accordingly, the upstream end t11 of the fuel supply path R1 is connected to the tank 30. The downstream end t12 of the fuel supply path R1 is connected to the injectors 34a to 34c.
[0016] The heater 32 is provided in the fuel supply path R1. The heater 32 changes the fuel in a liquid state into a gaseous state by heating it. The injectors 34a to 34c inject the fuel supplied through the fuel supply path R1. In the present embodiment, the injectors 34a to 34c inject the fuel changed into a gaseous state by the heater 32 into an intake path R11 described later.
[0017] Here, the engine 10 will be described while referring to FIG. 2. The engine 10 is a four-cycle engine that uses ammonia as fuel. In FIG. 2, although one cylinder is illustrated, the engine 10 includes three cylinders. However, since the structures of the three cylinders are the same, the description will be made focusing on one cylinder. The engine 10 includes an engine body 12, a crankshaft 14, a connecting rod 16, a piston 18, an intake valve 20, an exhaust valve 22, and an ignition device 23.
[0018] The engine body 12 includes a cylinder block 12a, a cylinder head 12b, and a crankcase 12c. A cylinder Sy is provided in the cylinder block 12a. The cylinder Sy has a cylindrical shape having a central axis extending along the vertical axis.
[0019] The cylinder head 12b is located above the cylinder block 12a. The cylinder head 12b is fixed to the cylinder block 12a. A combustion chamber Sp is provided in the cylinder head 12b. The combustion chamber Sp is located above the cylinder Sy. The combustion chamber Sp is connected to the cylinder Sy.
[0020] The cylinder head 12b is provided with an intake port P1 and an exhaust port P2. The intake port P1 and exhaust port P2 are connected to the combustion chamber Sp. The intake port P1 is part of the intake path R11. The intake path R11 is a pipe through which air or a mixture of fuel and air passes. The injector 34a is located in the intake path R11. The injector 34a injects gaseous fuel into the intake path R11. This forms a mixture. The exhaust port P2 is part of the exhaust path R12. The exhaust path R12 is a pipe through which exhaust gas passes. Thus, the engine 10 is provided with a combustion chamber Sp, an intake path R11 connected to the combustion chamber Sp, and an exhaust path R12.
[0021] The crankcase 12c is located below the cylinder block 12a. The crankcase 12c is fixed to the cylinder block 12a. The engine body 12 described above is made of cast iron.
[0022] The crankshaft 14 is supported by the cylinder block 12a and the crankcase 12c. The crankshaft 14 can rotate about a rotation axis perpendicular to the vertical axis.
[0023] The piston 18 is located within the cylinder Sy. The piston 18 has a cylindrical shape. The piston 18 can move upward and downward.
[0024] The connecting rod 16 connects the crankshaft 14 and the piston 18. As a result, when the crankshaft 14 rotates, the piston 18 moves up and down. The combustion chamber Sp mentioned above is the space enclosed by the piston 18 and the cylinder head 12b when the piston 18 is at top dead center (TDC).
[0025] The intake valve 20 is supported by the cylinder head 12b. The intake valve 20 is located downstream of the injector 34a in the intake path R11. The intake valve 20 opens and closes the intake path R11. When the intake valve 20 opens the intake path R11, a mixture of fuel and air flows from the intake path R11 into the combustion chamber Sp. The exhaust valve 22 is supported by the cylinder head 12b. The exhaust valve 22 opens and closes the exhaust path R12. When the exhaust valve 22 opens the exhaust path R12, exhaust gas flows out from Sp into the exhaust path R12. The intake valve 20 and exhaust valve 22 are driven by a valve train mechanism (not shown).
[0026] The ignition system 23 burns the fuel injected by the injector 34a. The ignition system 23 includes a spark plug 24 and an ignition coil 26. The spark plug 24 is fixed to the cylinder head 12b. The spark plug 24 includes a center electrode and a ground electrode. The center electrode and ground electrode are exposed to the combustion chamber Sp.
[0027] The ignition coil 26 applies a high voltage between the center electrode and the ground electrode of the spark plug 24 based on an ignition signal from a control device (not shown). This generates a spark between the center electrode and the ground electrode of the spark plug 24, igniting the fuel in the combustion chamber Sp.
[0028] The cooling path R2 shown in Figure 1 is a pipe through which fuel can pass. The upstream end of the cooling path R2 is called the upstream end t1. The downstream end of the cooling path R2 is called the downstream end t2. By connecting the upstream end t1 and the downstream end t2 of the cooling path R2 to the tank 30, the fuel in the tank 30 passes through the cooling path R2.
[0029] The pump 36, heater 37, compressor 38, condenser 40, expansion valve 42, evaporator 44, and compressor 46 are arranged in the cooling path R2 in this order from upstream to downstream. The pump 36 supplies liquid fuel from the tank 30 to the heater 37.
[0030] The heater 32 heats the liquid fuel, converting it into a gaseous state. This supplies the gaseous fuel at a low temperature and low pressure to the compressor 38. The compressor 38 pressurizes the gaseous fuel at a low temperature and low pressure in the cooling path R2. As a result, the compressor 38 supplies the gaseous fuel at a high temperature and high pressure to the condenser 40.
[0031] The condenser 40 cools the fuel pressurized by the compressor 38, supplying liquid fuel to the evaporator 44 via the expansion valve 42. More specifically, the gaseous fuel, which is at a high temperature and high pressure, passes through the condenser 40. The condenser 40 is exposed to the airflow generated by the vehicle moving forward. Therefore, the heat from the gaseous fuel, which is at a high temperature and high pressure, is removed by the airflow. As a result, the gaseous fuel, which is at a high temperature and high pressure, condenses and changes into liquid fuel.
[0032] The expansion valve 42 supplies atomized fuel to the evaporator 44 by injecting liquid fuel supplied from the condenser 40. This makes it easier for the atomized fuel to evaporate in the evaporator 44.
[0033] The evaporator 44 cools the surrounding air (fluid) by changing the atomized (liquid) fuel in the cooling path R2 into a gaseous fuel. More specifically, the atomized fuel passes through the evaporator 44. During this process, the atomized fuel changes into a gaseous fuel; that is, the atomized fuel evaporates. The evaporator 44 is exposed to the airflow generated by the vehicle moving forward. Therefore, as the atomized fuel evaporates, it absorbs heat from the airflow (fluid). In other words, the airflow is cooled as it passes through the evaporator 44.
[0034] Here, as shown in Figure 2, the evaporator 44 is located in front of the ignition coil 26, which is to be cooled. Also, at least a portion of the ignition coil 26 is located between the upper and lower ends of the evaporator 44. The air is cooled when the airflow from the vehicle hits the evaporator 44. The air (fluid) cooled by the evaporator 44 then cools the ignition coil 26, which is to be cooled in the vehicle to which the fuel supply system 1 is applied.
[0035] The compressor 46 pressurizes the gaseous fuel. This changes the gaseous fuel into a liquid state. The liquid fuel is then stored in the tank 30.
[0036] [effect] The fuel supply system 1 can cool the object to be cooled. More specifically, the evaporator 44 cools the air surrounding the evaporator 44 by changing the atomized fuel in the cooling path R2 into a gaseous state. As a result, the air cooled by the evaporator 44 can cool the object to be cooled in the vehicle to which the fuel supply system 1 is applied. Furthermore, since fuel is used as a refrigerant, it is not necessary to add a cooling system to the vehicle for cooling the object to be cooled. Therefore, the vehicle can be made more compact.
[0037] According to the fuel supply system 1, ammonia becomes easier to burn in the ammonia-fueled engine 10. More specifically, in order to achieve carbon neutrality, there is a need for engines that do not emit carbon dioxide in their exhaust gases. One example of such an engine is an ammonia-fueled engine. However, the laminar combustion rate of ammonia is lower than that of gasoline. Therefore, ammonia is more difficult to burn than gasoline. Thus, the ammonia-fueled engine 10 has the problem of difficulty in stably burning the fuel.
[0038] One way to solve the above problem is, for example, by having the ignition coil 26 supply high energy to the spark plug 24, causing the spark plug 24 to generate a powerful spark discharge. This makes it easier for ammonia to burn. On the other hand, when the ignition coil 26 supplies high energy to the spark plug 24, the ignition coil 26 heats up. Such heating of the ignition coil 26 can cause the ignition coil 26 to fail.
[0039] Therefore, in the fuel supply system 1, the ignition coil 26 is cooled by a cooling mechanism that uses ammonia, the fuel, as a refrigerant. As a result, even when the ignition coil 26 delivers high energy to the spark plug 24, the ignition coil 26 is less likely to overheat. Consequently, in the engine 10 that uses ammonia as fuel to achieve carbon neutrality, the ammonia burns more easily.
[0040] Furthermore, fuel is used as a refrigerant. Therefore, if fuel becomes insufficient, the vehicle will be unable to run due to lack of fuel, and the ignition coil 26 will not be cooled. In other words, the possibility of the vehicle running with the ignition coil 26 not being cooled is reduced. As a result, the probability of ignition coil 26 failure can be reduced.
[0041] In the fuel supply system 1, the evaporator 44 is located in front of the ignition coil 26, which is to be cooled. As a result, the airflow passing through the evaporator 44 hits the ignition coil 26. Consequently, the ignition coil 26 is efficiently cooled.
[0042] (Other embodiments) The fuel supply system and vehicle according to the present invention are not limited to fuel supply system 1, but can be modified within the scope of its gist.
[0043] In addition, the fuel in the fuel supply system 1 is not limited to ammonia. The fuel may also be an alcohol such as ethanol or methanol.
[0044] Furthermore, the fluid cooled by the evaporator 44 is not limited to air. The fluid may be a liquid such as water or oil, or it may be used to cool the intake air of the engine 10.
[0045] Note that the object to be cooled is not limited to the ignition coil 26. The object to be cooled may be the engine, motor, etc., or the air inside the vehicle's cabin.
[0046] Engine 10 is a port injection type engine. However, engine 10 may also be a direct injection type engine. That is, injectors 34a to 34c may inject fuel directly into the combustion chamber Sp.
[0047] Furthermore, the fuel that is consumed by tank 30 may be in a gaseous state. In this case, the pump 36, heater 37, and compressor 46 are unnecessary.
[0048] The evaporator 44 may also surround the ignition coil 26. This allows the ignition coil 26 to be cooled more efficiently.
[0049] Furthermore, hydrogen may be used as a combustion aid for ammonia.
[0050] Although injectors 34a to 34c inject ammonia in a gaseous state, they may also inject ammonia in a liquid state. [Explanation of Symbols]
[0051] 1: Fuel supply system 10: Engine 12: Engine body 12a: Cylinder block 12b: Cylinder head 12c: Crankcase 14: Crankshaft 16: Connecting Rod 18: Piston 20: Intake valve 22: Exhaust valve 23:Ignition device 24: Spark plug 26: Ignition coil 30: Tank 32: Heater 34a~34c: Injector 36: Pump 37: Heater 38: Compressor 40: Capacitor 42: Expansion valve 44: Evaporator 46: Compressor P1: Intake port P2: Exhaust port R1: Fuel supply route R2: Cooling path R11: Intake path R12: Exhaust path Sp: Combustion chamber Sy: Cylinder t1: upstream end t2: downstream end
Claims
1. The fuel supply system comprises a tank, a fuel supply path, a cooling path, and an evaporator. The aforementioned tank contains fuel, The fuel supply path supplies fuel from the tank to the injector. The injector injects the fuel supplied through the fuel supply path, The upstream end and the downstream end of the cooling path are connected to the tank, so that the fuel in the tank passes through the cooling path. The evaporator cools the fluid surrounding it by changing the liquid fuel in the cooling path into a gaseous fuel. The fluid cooled by the evaporator cools the cooling target of the vehicle to which the fuel supply system is applied. Fuel supply system.
2. The fluid is air, The airflow generated by the vehicle moving forward strikes the evaporator, thereby cooling the air. The evaporator is located in front of the object to be cooled. The fuel supply system according to claim 1.
3. The fuel supply system further comprises a compressor and a condenser. The compressor, the condenser, and the evaporator are arranged in the cooling path in this order from upstream to downstream. The compressor pressurizes the fuel in the cooling path, The condenser supplies liquid fuel to the evaporator by cooling the fuel pressurized by the compressor. A fuel supply system according to claim 1 or claim 2.