| 摘要 |
A propulsion system comprises of a flow passage (173) having an intake (175) for communicating with a source of working fluid such as seawater and an outlet (177). A mixing zone (209) is disposed within the flow passage (173) between the intake (175) and the outlet (177). An injection means including annular nozzle (217) is provided for injecting a hot compressible driving fluid (175) such as steam into the mixing zone (209) in a flow direction towards the outlet (177). The arrangement is such that the interaction between the steam and the seawater in the mixing zone (207) develops a pressure reduction in the mixing zone (207) to cause seawater to be drawn from the source into the mixing zone (207) and propelled towards the outlet (177). A marine drive unit incorporating the propulsion system is also claimed. A heat recovery system comprising a refrigerant circuit with a heat exchanger for extracting heat from a heat source to vapourise a refrigerant in the circuit and means to convert heat energy in the vapourised refrigerant to torque and, a nozzle means (217) having an inlet, an outlet (177) and a flow passage (173) the size of which is selectively variable are also disclosed. |
