Apparatus for downhole power generation

摘要

An electrical power generator, for use in a fluid-containing pipe, comprises an annular power generation assembly comprising a fluid-flow-driven impeller connected to one of a magnet assembly or an electrical coil assembly. The magnet assembly and the coil assembly are arranged for magnetic coupling between them and are mounted to enable relative movement between them, such that fluid flowing past the impeller causes relative rotation between the magnet assembly and the coil assembly for the generation of electrical power. A flow controller 490 is located closer to the longitudinal axis of the pipe than the annular power generation assembly and is detachable from the annular power generation assembly so that it can be removed to leave an axially-located through bore. The flow controller may comprise an adaptive flow control nozzle and may comprise a spring collet for latching engagement with the power generation assembly.