All External Combustion Engines

Heat engines in which the fuel is burned outside the working cylinder and the heat passes through a wall or heat exchanger to the working fluid, such as the Stirling engine and the wider family of external combustion engines. A technology belongs here when its cited article describes an external combustion engine or a heat engine heated from outside. It excludes internal combustion engines, where the fuel burns inside the cylinder, and steam engines listed with the steam group, and this group is kept apart because these engines can run on any source of heat, including sunlight and waste heat.