Power system and engine cleaning method

Abstract

To provide a power system and an engine cleaning method capable of maintaining a state where accumulation of carbon within an engine and in an exhaust pipe is prevented.SOLUTION: A power system includes an engine, a power section configured to be driven by the engine and a gas supply section configured to supply cleaning gas containing hydrogen gas and oxygen gas. The gas supply section is configured to continuously supply the cleaning gas to air intake of the engine when the power section is driven by the engine. In an engine cleaning method, the cleaning gas containing hydrogen gas and oxygen gas is continuously supplied to the air intake of the engine when the engine drives the power section.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] FIELD OF THE DISCLOSURE The present disclosure relates to power systems and engine washing methods. [Background technology]

[0002] Patent Documents 1 and 2 describe engine washing methods. In the engine washing method described in Patent Document 1, hydrogen gas is supplied into the combustion chamber of the engine. In the engine washing method described in Patent Document 2, a mixed gas of hydrogen gas and oxygen gas is supplied to the intake port of the engine. The engine washing methods described in Patent Documents 1 and 2 aim to remove carbon that has accumulated inside the engine and in the exhaust pipe. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 7093579 [Patent Document 2] Patent No. 5926359 Summary of the Invention [Problem to be solved by the invention]

[0004] Even if carbon can be temporarily removed by implementing the engine washing methods described in Patent Documents 1 and 2, carbon will accumulate again inside the engine and in the exhaust pipe as the engine is used thereafter. In one aspect of the present disclosure, it is preferable to provide a power system and an engine washing method that can maintain a state in which carbon is less likely to accumulate inside the engine and in the exhaust pipe. [Means for solving the problem]

[0005] One aspect of the present disclosure is a power system including an engine, a power unit configured to be powered by the engine, and a gas supply unit configured to supply a cleaning gas including hydrogen gas and oxygen gas, wherein the gas supply unit is configured to continuously supply the cleaning gas to an air intake of the engine when the power unit is powered by the engine. According to a power system that is one aspect of the present disclosure, it is possible to maintain a state in which carbon is less likely to accumulate inside the engine and in the exhaust pipe.

[0006] Another aspect of the present disclosure is a method for washing an engine, comprising continuously supplying a cleaning gas comprising hydrogen gas and oxygen gas to an air intake of the engine while the engine is running a power section.

[0007] According to the engine washing method that is another aspect of the present disclosure, it is possible to maintain a state in which carbon is less likely to accumulate inside the engine and in the exhaust pipe. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 2 is a block diagram showing the configuration of a power system. [Figure 2] 10 is a photograph showing a cloth on which soot discharged from an exhaust pipe has been collected before the first day of operation in Example 3. [Figure 3] 10 is a photograph showing a cloth collecting soot discharged from an exhaust pipe after the fourth day of operation in Example 3. DETAILED DESCRIPTION OF THE INVENTION

[0009] Exemplary embodiments of the present disclosure will now be described with reference to the drawings. First Embodiment 1. Power System 1 Configuration The configuration of the power system 1 will be described with reference to Fig. 1. The power system 1 is a power source for, for example, a mobile body, a generator, construction machinery, etc. Examples of mobile bodies include ships, vehicles, and aircraft. The power system 1 is mounted on, for example, a mobile body, a generator, construction machinery, etc.

[0010] The power system 1 includes an engine 3, a power unit 5, a gas supply unit 7, an exhaust pipe 9, and a generator 11. The engine 3 may be, for example, a gasoline engine, a diesel engine, or a gas engine.

[0011] The power unit 5 is a member configured to be moved by the engine 3. Examples of the power unit 5 include a ship's propeller and a vehicle's wheels. For example, the power unit 5 can be switched between a state connected to the engine 3 and a state disconnected from the engine 3. When the power unit 5 is connected to the engine 3, it is moved by the engine 3. When disconnected from the engine 3, the power unit 5 is not moved by the engine 3 even if the engine 3 is running.

[0012] The gas supply unit 7 is a member configured to supply a cleaning gas containing hydrogen gas and oxygen gas to the air intake 8 of the engine 3. The gas supply unit 7 continuously supplies the cleaning gas to the air intake 8 when the power unit 5 is driven by the engine 3.

[0013] The power unit 5 is driven by the engine 3 when, for example, a mobile body equipped with the power system 1 is moving, when the mobile body equipped with the power system 1 is stopped but the engine 3 is running, when a generator equipped with the power system 1 is generating electricity, or when construction machinery equipped with the power system 1 is operating. When a mobile body is moving is when, for example, a ship is sailing or a vehicle is running.

[0014] The gas supply unit 7 includes a gas generator 21, a battery 23, and a main switch 25. The gas generator 21 is a device that generates a cleaning gas containing hydrogen gas and oxygen gas by electrolyzing an electrolyte aqueous solution in which an electrolyte is dissolved. Examples of the electrolyte include sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, sodium sulfate, and sodium bicarbonate. The concentration of the electrolyte in the electrolyte aqueous solution is, for example, 0.1 to 10% by mass, and preferably 0.5 to 5% by mass.

[0015] A commercially available example of the gas generator 21 is the hybrid fuel reduction device HFR-3000 (manufactured by Eight Factory Co., Ltd., registered trademark). In addition, the "cleaning gas generator 2" described in paragraphs 0026 to 0035 and FIG. 2 of the specification of Patent Document 2 can be used as the gas generator 21.

[0016] The cleaning gas is, for example, a gas containing hydrogen gas and oxygen gas as its main components. For example, the volume ratio of hydrogen gas to oxygen gas in the cleaning gas is 2:1. For example, the cleaning gas does not contain any components other than hydrogen gas and oxygen gas, except for impurities. Examples of impurities include water vapor and trace components in the atmosphere. The cleaning gas may contain, for example, hydrogen gas, oxygen gas, and O - (monovalent oxygen radical), O 2- (divalent oxygen radical), OH - (oxygen hydrogen radical), and some or all of O3 (ozone).

[0017] The cleaning gas generated by the gas generator 21 is supplied to the air intake 8. The air intake 8 draws in the cleaning gas together with air. For example, the cleaning gas is naturally drawn in through the air intake 8. The greater the amount of air drawn into the air intake 8, the greater the amount of cleaning gas drawn into the air intake 8.

[0018] The battery 23 supplies power for electrolysis to the gas generator 21. The main switch 25 turns on / off the electrical connection between the battery 23 and the gas generator 21. The main switch 25 is on when the engine 3 is running. The main switch 25 is off when the engine 3 is stopped.

[0019] The exhaust pipe 9 exhausts the exhaust gas generated by the engine 3. The generator 11 charges the battery 23 using the driving force of the engine 3. The voltage supplied by the battery 23 to the gas generator 21 increases as the rotation speed of the engine 3 increases. For example, when the rotation speed of the engine 3 is 600 rpm, the voltage supplied by the battery 23 to the gas generator 21 is 24 V. Also, when the rotation speed of the engine 3 is 3000 rpm, the voltage supplied by the battery 23 to the gas generator 21 is 30 V. Therefore, the gas supply unit 7 supplies more cleaning gas to the air intake 8 as the rotation speed of the engine 3 increases.

[0020] 2. Engine cleaning method performed by power system 1 The power system 1 continuously supplies cleaning gas to the air intake 8 of the engine 3 when the engine 3 is powering the power section 5 .

[0021] The engine 3 is operating the power unit 5 when, for example, a mobile body equipped with the power system 1 is moving, when a generator equipped with the power system 1 is generating electricity, or when construction machinery equipped with the power system 1 is operating. The mobile body is moving when, for example, a ship is sailing or a vehicle is traveling.

[0022] The greater the amount of air drawn into the air intake 8, the greater the amount of cleaning gas drawn into the air intake 8. The gas supply unit 7 supplies a larger amount of cleaning gas to the air intake 8 as the rotation speed of the engine 3 increases.

[0023] 3. Effects of the power system 1 and engine cleaning method (1A) When the power unit 5 is driven by the engine 3, the power system 1 continuously supplies cleaning gas to the air intake 8. This makes it possible to maintain a state in which carbon is less likely to accumulate inside the engine 3 or in the exhaust pipe 9.

[0024] (1B) In the engine washing method performed by the power system 1, cleaning gas is continuously supplied to the air intake 8 of the engine 3 while the engine 3 is operating the power unit 5. This makes it possible to maintain a state in which carbon is less likely to accumulate inside the engine 3 and in the exhaust pipe 9.

[0025] (1C) In the power system 1 and the engine cleaning method, the greater the amount of air drawn into the air intake 8, the greater the amount of cleaning gas drawn into the air intake 8. Therefore, even if the rotation speed of the engine 3 changes and the amount of air drawn into the air intake 8 changes, the concentration of cleaning gas inside the engine 3 can be maintained within an appropriate range. The appropriate range is a range in which adhesion of carbon to the inside of the engine 3 and the exhaust pipe 9 can be suppressed and the load on the engine 3 is reduced.

[0026] (1D) In ​​the power system 1 and the engine cleaning method, the higher the rotation speed of the engine 3, the more cleaning gas is supplied to the air intake 8. Therefore, even if the rotation speed of the engine 3 changes and the amount of air intake into the air intake 8 changes, the concentration of cleaning gas inside the engine 3 can be maintained within an appropriate range. The appropriate range is a range in which adhesion of carbon to the inside of the engine 3 and the exhaust pipe 9 can be suppressed and the load on the engine 3 can be reduced.

[0027] (1E) The power system 1 can reduce the amount of fuel consumed by the engine 3 compared to when cleansing gas is not supplied to the air intake 8. This is presumably because the hydrogen gas contained in the cleansing gas acts as fuel for the engine 3.

[0028] (1F) The power system 1 supplies power to the gas generator 21 using the generator 11. Therefore, it is not necessary to provide a dedicated power source for the gas generator 21. (1G) In the power system 1 and the engine washing method, the amount of cleaning gas supplied to the engine 3 per unit time can be smaller than in the engine washing methods described in Patent Documents 1 and 2. Therefore, the load on the engine 3 is small, and the life of the engine 3 can be extended.

[0029] 4. Example 1 (1) Configuration of Power System 1 in First Embodiment A power system 1 having the configuration described above in "1. Configuration of power system 1" was prepared. In this example, the power system 1 was installed on a ship. The power system 1 was the power source of the ship. The ship was a 7.3-ton EP ship. The power unit 5 was the ship's screw. The engine 3 was a Yanmar 6CA-GT. The gas generator 21 was a hybrid fuel reduction device HFR-3000 (manufactured by Eight Factory Co., Ltd.). The cleaning gas was a gas containing hydrogen gas and oxygen gas as its main components. In the cleaning gas, the volume ratio of hydrogen gas to oxygen gas was 2:1. In addition to hydrogen gas and oxygen gas, the cleaning gas also contained O - (monovalent oxygen radical), O 2- (divalent oxygen radical), OH - (oxygen hydrogen radical), and O3 (ozone).

[0030] (2) Fuel efficiency measurement The vessel was operated under the following conditions A and B, respectively. Condition A: Cleaning gas was continuously supplied to the air intake 8 while the vessel was in operation. The greater the amount of air drawn into the air intake 8, the greater the amount of cleaning gas drawn into the air intake 8. Furthermore, the higher the rotation speed of the engine 3, the more cleaning gas the gas supply unit 7 supplied to the air intake 8. The relationship between the rotation speed of the engine 3 and the voltage V supplied by the battery 23 to the gas generator 21 was as shown in Table 1.

[0031] [Table 1]

[0032] Condition B: No cleaning gas was supplied to the air intake 8 while the vessel was in operation. The amount of fuel consumed per hour of ship operation (hereafter referred to as fuel consumption) was calculated under conditions A and B. The results are shown in Table 2. Fuel consumption measurements were conducted twice for each of conditions A and B.

[0033] [Table 2]

[0034] The fuel consumption under condition A was significantly reduced compared to the fuel consumption under condition B.

[0035] 5. Example 2 (1) Configuration of Power System 1 in Example 2 A power system 1 having the configuration described above in "1. Configuration of Power System 1" was prepared. In this example, the power system 1 was mounted on a diesel generator. The power system 1 was the power source of the diesel generator. The engine 3 was a diesel engine (manufactured by Yamaha, model number: 4TNE88-RAG2). The gas generator 21 was a hybrid fuel reduction device HFR-3000 (manufactured by Eight Factory Co., Ltd.). The cleaning gas was a gas containing hydrogen gas and oxygen gas as its main components. In the cleaning gas, the volume ratio of hydrogen gas to oxygen gas was 2:1. The cleaning gas contained hydrogen gas, oxygen gas, and O - (monovalent oxygen radical), O 2- (divalent oxygen radical), OH - (oxygen hydrogen radical), and O3 (ozone).

[0036] (2) Operation of diesel generators The diesel generator was operated every day for seven days. On the first day, it was operated continuously for two hours. On days two through seven, it was operated continuously for one hour each. While the diesel generator was operating, cleaning gas was continuously supplied to air intake 8. After operation on the first day ended, soot began to fall off the injector of engine 3.

[0037] At the end of operation on the first day, the end of operation on the fourth day, and the end of operation on the seventh day, the top of the piston, the top of the cylinder, and the cylinder valve surface of Engine 3 were observed. From the observation results, it was confirmed that carbon deposition had decreased in Engine 3. The reason for the decrease in carbon deposition in the above test is presumed to be as follows.

[0038] The carbon referred to here is carbon atoms produced by the decomposition of hydrocarbons, a compound of carbon and hydrogen, or soot, which is an agglomeration of carbon atoms. Since the black-looking substance is thought to be an agglomeration of carbon, the substance released into the air or adhering to a wall surface is referred to as soot. Because the size (i.e., diameter) of carbon atoms is shorter than the wavelength of visible light, they cannot be seen with the naked eye even when released into the air. However, when multiple or more carbon atoms agglomerate and the size of the agglomerated soot becomes larger than the wavelength of visible light, it becomes visible to the naked eye and appears as black smoke.

[0039] Similarly, when soot adheres to the inside of the combustion chamber or the wall of the exhaust pipe of the engine 3, it becomes soot that appears black to the naked eye when it reaches a certain size, just like soot that is formed by carbon condensation in the air.

[0040] On the other hand, in the power system 1, the cleaning gas generated by the electrolysis of water is presumed to contain some or all of the following radicals (i) to (iv) and ozone. (i)O - (monovalent oxygen radical) (ii)O 2- (divalent oxygen radical) (iii)OH- (oxygen hydrogen radical) (iv) O3 (ozone)

[0041] O - Because monovalent oxygen radicals (monovalent oxygen radicals) are highly reactive, they can combine with carbon contained in soot to form CO. This reaction reduces the amount of soot in the air or on the wall surface. The CO (carbon monoxide) generated in this process is a colorless, transparent gas at room temperature and pressure, so it is difficult to see with the naked eye even when it is emitted. Therefore, the carbon itself does not disappear, but rather it is emitted in a different form, and the reduction in soot is only noticeable.

[0042] O 2- (divalent oxygen radical) is O - It may react with monovalent oxygen radicals to become CO2 (carbon dioxide). CO2 (carbon dioxide) is also a colorless, transparent gas at room temperature and pressure, so it is difficult to detect with the naked eye when it is emitted. Furthermore, CO (carbon monoxide) is non-polar and does not dissolve in water, which is a polar solvent, but CO2 (carbon dioxide) dissolves in water, so it comes out in the water in the exhaust, making it even more difficult to detect when it is emitted.

[0043] O 2- (divalent oxygen radical) is O - Because it is more reactive than the monovalent oxygen radical (O radical), it may combine with carbon contained in soot to form CO. This reaction is recognized as a reduction in soot because O - This is the same as for (monovalent oxygen radical).

[0044] OH - (elementary hydrogen radical) is highly active and reacts as follows to form OH - Two hydrogen radicals combine to form H2O2 (hydrogen peroxide). OH - + OH - = H2O2 However, because H2O2 (hydrogen peroxide) is unstable, it reacts as follows to form water and O -(monovalent oxygen radical) and the resulting O - (monovalent oxygen radicals) will also reduce soot through the same process as above. H2O2 = H2O + O -

[0045] O3 (ozone) is also highly active and may react with the carbon in the soot. - (monovalent oxygen radical) and O 2- (divalent oxygen radical) and OH - It is thought that O3 (ozone) contributes to the reduction of soot through a process similar to that of hydrogen radicals. However, when O3 (ozone) reaches temperatures above 400°C, it reacts as follows and decomposes: O3 = O2 + O -

[0046] Therefore, when cleaning gas is introduced into the air intake 8 of the engine 3 as in the present disclosure, there is a high possibility that O3 (ozone) is decomposed by entering the combustion chamber of the engine. Therefore, it is not O3 (ozone) itself that is introduced, but the decomposed O3. - It is speculated that the soot reduction process is most likely due to the action of monovalent oxygen radicals.

[0047] Next, in the case of Example 1, the reason why fuel consumption was reduced under Condition A is presumed to be as follows: The reduction in soot described above targets the soot present in the exhaust gas of the engine 3, whereas the improvement in fuel consumption targets the reaction with fuel in the combustion process of the engine 3.

[0048] Here, when discussing fuel efficiency, we will mention the efficiency of engine 3. The efficiency of engine 3 is the ratio of the energy obtained from engine 3 to the energy of the fuel input. On the other hand, fuel efficiency is the ratio of the work obtained to the cost of the fuel input. Therefore, improving fuel efficiency can be considered as improving efficiency. The formula that defines the efficiency of engine 3 is given below. Engine 3 efficiency = combustion efficiency x mechanical conversion efficiency

[0049] Here, combustion efficiency is the percentage of fuel that contributed to combustion, i.e., oxidation reaction, among the fuel input. Mechanical conversion efficiency is the percentage of thermal energy generated by fuel combustion that the engine 3 mechanism was able to convert into kinetic energy.

[0050] Therefore, the improvement in efficiency is due to either an improvement in combustion efficiency or an improvement in mechanical conversion efficiency. The effect of the present disclosure is unlikely to affect the mechanism of the engine 3, and is thought to be due to the improvement in the former combustion efficiency. Combustion occurs when C (carbon) or H (hydrogen) in the fuel reacts with O (oxygen), and an increase in this ratio improves combustion efficiency. Fuel components that do not contribute to the reaction during combustion in the engine 3 are released into the exhaust as HC (hydrocarbon).

[0051] This is due to some or all of the radicals (i) to (iv) and ozone generated by the electrolysis of water using the power system 1. The radicals (i) to (iv) and ozone all promote oxidation reactions, and the reaction described in the soot reduction is the basic mechanism.

[0052] Here, while the reduction in soot mentioned above targets the soot present in the exhaust gas of the engine 3, the improvement in fuel efficiency targets the reaction with fuel during the combustion process of the engine 3. In other words, it targets the carbon molecules contained in the gas inside the combustion chamber that is generated by decomposition of the vaporized fuel. It also targets the hydrogen contained in the gas inside the combustion chamber that is generated by decomposition of the vaporized fuel. Therefore, it is thought that the improvement in fuel efficiency is due to the promotion of this oxidation reaction, that is, the improvement in the proportion of fuel that can effectively contribute to the reaction out of the fuel that is input.

[0053] 6. Example 3 (1) Configuration of Power System 1 in Third Embodiment A power system 1 having the configuration described above in "1. Configuration of power system 1" was prepared. In this example, the power system 1 was mounted on a vehicle. The power system 1 was the power source of the vehicle. The power unit 5 was the wheels of the vehicle. The engine 3 was a diesel engine (manufactured by Nissan, model number: KC-CD45). The displacement of the engine 3 was 12,500 cc.

[0054] The gas generator 21 was a hybrid fuel reduction device HFR-3000 (manufactured by Eight Factory Co., Ltd.). The cleaning gas was a gas mainly composed of hydrogen gas and oxygen gas. The volume ratio of hydrogen gas to oxygen gas in the cleaning gas was 2:1. The cleaning gas contained O - (monovalent oxygen radical), O 2- (divalent oxygen radical), OH - (oxygen hydrogen radical), and O3 (ozone).

[0055] (2) Vehicle operation The vehicle was operated every day for four days. On the first day, no cleaning gas was supplied to the air intake 8 while the vehicle was operating. On the second to fourth days, cleaning gas was continuously supplied to the air intake 8 while the vehicle was operating. The greater the amount of air drawn into the air intake 8, the greater the amount of cleaning gas drawn into the air intake 8. Furthermore, the higher the rotation speed of the engine 3, the more cleaning gas the gas supply unit 7 supplied to the air intake 8.

[0056] Table 3 shows the vehicle mileage, diesel consumption, and mileage per liter of diesel for each day.

[0057] [Table 3]

[0058] As shown in Table 3, on days 2 to 4, when cleaning gas was continuously supplied to the air intake 8, the mileage per liter of diesel was significantly longer than on day 1, when no cleaning gas was supplied to the air intake 8 at all.

[0059] Before the first day of operation, soot emitted from exhaust pipe 9 was collected on a gray cloth. The cloth is shown in Figure 2. After the fourth day of operation, soot emitted from exhaust pipe 9 was collected on a gray cloth. The cloth is shown in Figure 3. Before the first day of operation, a large amount of soot was emitted from exhaust pipe 9. After the fourth day of operation, the amount of soot emitted from exhaust pipe 9 had significantly decreased.

[0060] <Other embodiments> Although the embodiments of the present disclosure have been described above, the present disclosure is not limited to the above-described embodiments and can be implemented in various modified forms.

[0061] (1) The function of one component in each of the above embodiments may be shared among multiple components, or the functions of multiple components may be performed by one component. Also, part of the configuration of each of the above embodiments may be omitted. Furthermore, at least part of the configuration of each of the above embodiments may be added to or substituted for the configuration of another of the above embodiments.

[0062] (2) In addition to the power system 1 described above, the present disclosure can also be realized in various forms, such as a higher-level system that includes the power system 1 as a component, a control method for the power system 1, and a method for improving engine fuel efficiency. [Explanation of symbols]

[0063] 1...power system, 3...engine, 5...power section, 7...gas supply section, 8...air intake, 9...exhaust pipe, 11...generator, 21...gas generator, 23...battery, 25...main switch

Claims

1. The engine and a power unit configured to be driven by the engine; a gas supply configured to supply a cleaning gas including hydrogen gas and oxygen gas; Equipped with the gas supply is configured to continuously supply the cleaning gas to the engine air intake when the power unit is powered by the engine; Power system.

2. 10. The power system of claim 1, The greater the amount of air drawn into the air intake, the greater the amount of cleaning gas drawn into the air intake. Power system.

3. 3. The power system according to claim 1 or 2, The gas supply unit supplies a larger amount of the cleaning gas as the engine speed increases. Power system.

4. When the engine is operating a power unit, a cleaning gas containing hydrogen gas and oxygen gas is continuously supplied to an air intake of the engine. How to wash an engine.

5. 5. The engine washing method according to claim 4, The greater the intake volume at the air intake, the greater the amount of cleaning gas drawn into the air intake. How to wash an engine.

6. 6. The engine washing method according to claim 4 or 5, The higher the engine speed, the more cleaning gas is supplied. How to wash an engine.

Images