JP-2026074548-A - Methods for improving engine combustion

Abstract

[Problem] To provide an engine operation method that optimizes the amount of hydrogen gas added to the intake air of an engine with a constant rotational speed. [Solution] The amount of fuel to be added is calculated based on the propeller pitch of the variable-pitch propeller, the engine output, or the engine characteristics corresponding to the determined power generation. The optimal amount of hydrogen gas or a mixture of hydrogen gas and oxygen gas to be added to this fuel amount is then calculated. The amount of electrolytic electricity required to generate the calculated amount of gas is supplied to the electrolytic gas generator, and the generated gas is added to the air supplied to the engine. [Selection Diagram] Figure 1

Inventors

• 伊藤 雅則
• 原田 努

Assignees

• 株式会社ＨＩＴ研究所

Dates

Publication Date

20260507

Application Date

20241021

Claims (1)

1. An engine operation method characterized by adding hydrogen gas or a mixture of hydrogen gas and oxygen gas to the air supply to an engine whose rotational speed is controlled to a constant level, by calculating the amount of fuel to be added, which is determined by the propeller pitch of a determined variable-pitch propeller, the determined engine output, or the characteristics of the engine corresponding to the determined power generation, calculating the optimal amount of hydrogen gas or a mixture of hydrogen gas and oxygen gas to be added to this amount of fuel, supplying the amount of electrolysis current necessary to generate the calculated amount of gas to an electrolysis gas generator, and adding the generated gas to the air supply to the engine.

Description

This invention relates to a method for improving engine combustion by adding a small amount of hydrogen gas to the intake air. In Patent Document 1, the present inventors propose adding a small amount (0.01 to 0.1 vol%) of hydrogen to the intake air as a method for efficiently burning polymeric liquid fuels such as gasoline, diesel, or heavy oil in an engine. Furthermore, the inventors have made the following proposal, which is based on the premise of adding a small amount of hydrogen to the supply air. Patent Document 2 discloses a hydrogen gas supply system comprising a hydrogen gas generator that generates hydrogen gas (oxygen gas) by electrolyzing pure water, and a hydrogen storage alloy cylinder (canister) filled with a hydrogen storage alloy. The hydrogen gas generated by the hydrogen gas generator is supplied to the air supply line 7 (including the turbocharger) via a main line (piping). A sub-line is connected to the main line to supply hydrogen gas from the hydrogen storage alloy cylinder to the main line. Pressure regulating valves are provided in both the main line and the sub-line. A signal regarding the engine speed is sent from the governor to a control device, and a signal corresponding to the valve opening for supplying the amount of added hydrogen according to the engine load is sent from this control device to the pressure regulating valve. Patent Document 3 discloses a system in which a governor, installed to keep the engine speed within a certain range, sends a signal corresponding to the engine speed to a control device. The control device, upon receiving this signal, then sends a signal to a control valve in the intake line to supply hydrogen gas in an amount corresponding to the engine load and within the range below the explosion limit. Patent Document 4 discloses that hydrogen gas supplied simultaneously to the cylinder along with fuel gas ignites upon ignition of ammonia gas, and because the flame propagation speed (relative movement speed of the flame surface) of hydrogen gas is extremely fast compared to that of ammonia gas, the movement of the hydrogen gas flame surface promotes mixing of ammonia gas and air within the cylinder, thereby accelerating the complete combustion of ammonia gas. Patent No. 6328186Patent No. 6825150Patent No. 7479603Patent No. 7079890 A diagram illustrating the engine operation method according to the present invention.A diagram illustrating another embodiment.A diagram illustrating another embodiment.A diagram illustrating another embodiment.A diagram illustrating another embodiment. Embodiments of the present invention will be described below with reference to the accompanying drawings. The engine operation method according to the present invention is preferably applied to variable-pitch propeller engines for ships, generator engines, or electric propulsion engines for ships. In variable-pitch propeller ships, the ship's speed is changed by altering the propeller pitch. In this case, since the engine load changes depending on the propeller pitch, the governor controls the fuel input to maintain a constant engine speed. Similarly, in generator engines and electric propulsion ships, the governor controls the fuel input to maintain a constant engine speed according to the power load. As shown in Figure 1, in this invention, the amount of air supplied is calculated based on the propeller pitch, engine output, or generated power, corresponding to the fuel input amount determined by the engine characteristics. In terms of engine characteristics, the intake air volume corresponds to the amount of fuel supplied for engine output according to the load, at a constant rotational speed. Next, the amount of hydrogen gas (a mixture of hydrogen and oxygen gas) supplied to the intake air (amount of added gas) corresponding to the intake air volume calculated above is determined. As the required engine output increases, the fuel ratio in the intake air also increases, and along with the amount of intake air needed to completely burn the increased fuel, the amount of hydrogen gas (a mixture of hydrogen and oxygen gas) added also increases. Then, the amount of hydrogen gas to be added (a mixture of hydrogen and oxygen gas) is calculated, and the electrolytic current required to generate this amount in the electrolyzer is determined. The necessary amount of hydrogen and oxygen gas is then generated in the electrolyzer. Either the generated hydrogen gas alone, or a mixture of the generated hydrogen and oxygen gases, is added to the intake air supplied to the engine. Figure 2 illustrates another embodiment. In this embodiment, the main engine, whose speed is changed by rotational speed, and the auxiliary engine for power generation, which operates at a constant rotational speed, are controlled by separate systems. For the main engine, the amount of hydrogen gas added is determined according to the engine speed, as in the conventional method. For auxiliary engines for gener