Abstract: A two-stroke engine (1) includes a cylinder (2) having a scavenging port (23) and an exhaust port (24), a piston (3) provided in the cylinder (2), a first ejection part (61) for ejecting liquid ammonia into a combustion chamber (20), and a supercharger (5) for pressurizing a suction gas to generate a scavenging gas. In the two-stroke engine (1), the first ejection part (61) ejects liquid ammonia into the combustion chamber (20) within a period of time from when supply of the scavenging gas through the scavenging port (23) into the combustion chamber (20) is started until when the piston (3) next reaches top dead center. It is thus possible to reduce the temperature of gas within the combustion chamber (20) by the heat of vaporization of the liquid ammonia, reduce the pressure in the combustion chamber (20) during compression, and reduce the amount of compression work.

Abstract: An exhaust gas exhausted from a combustion chamber of a two-stroke engine is fed to a turbine of a supercharger. Part of the exhaust gas that has passed through the turbine is extracted as an EGR gas by an exhaust gas recirculation part. The EGR gas is cooled by the heat of vaporization of liquid ammonia ejected from an ammonia ejection part, circulated into a suction gas in a suction path, pressurized by a compressor, and supplied as a scavenging gas into the combustion chamber. This recirculation of the exhaust gas can reduce the amount of nitrogen oxide exhausted from the two-stroke engine into the ambient air. Ejecting the liquid ammonia toward the EGR gas in a recirculation path facilitates cooling of the EGR gas, which is required for circulating the EGR gas into the suction gas.

Abstract: An injection apparatus (6) includes a container (62), a liquid ammonia supply part (69) for supplying a predetermined amount of liquid ammonia into the container (62), a compression part (65) connected to the container (62) and for compressing a gas filled in a space for compression to introduce the compressed gas into the container (62), and a nozzle (66) connected to the container (62) and for introducing into a combustion chamber ammonia that is pushed out of the container (62) due to the introduction of the compressed gas into the container (62). The injection apparatus (6) uses a gas that is heated to a high temperature by compression to inject ammonia into the combustion chamber and thus can easily produce the combustion of ammonia in the combustion chamber.

Abstract: An exhaust gas exhausted from a combustion chamber of a two-stroke engine is fed to a turbine of a supercharger. Part of the exhaust gas that has passed through the turbine is extracted as an EGR gas by an exhaust gas recirculation part. The EGR gas is cooled by the heat of vaporization of liquid ammonia ejected from an ammonia ejection part, circulated into a suction gas in a suction path, pressurized by a compressor, and supplied as a scavenging gas into the combustion chamber. This recirculation of the exhaust gas can reduce the amount of nitrogen oxide exhausted from the two-stroke engine into the ambient air. Ejecting the liquid ammonia toward the EGR gas in a recirculation path facilitates cooling of the EGR gas, which is required for circulating the EGR gas into the suction gas.

Abstract: A two-stroke engine (1) includes a cylinder (2) having a scavenging port (23) and an exhaust port (24), a piston (3) provided in the cylinder (2), a first ejection part (61) for ejecting liquid ammonia into a combustion chamber (20), and a supercharger (5) for pressurizing a suction gas to generate a scavenging gas. In the two-stroke engine (1), the first ejection part (61) ejects liquid ammonia into the combustion chamber (20) within a period of time from when supply of the scavenging gas through the scavenging port (23) into the combustion chamber (20) is started until when the piston (3) next reaches top dead center. It is thus possible to reduce the temperature of gas within the combustion chamber (20) by the heat of vaporization of the liquid ammonia, reduce the pressure in the combustion chamber (20) during compression, and reduce the amount of compression work.