Apparatus and method for electric spark peening of gas turbine components

Peening provides compression of component (6, 46, 56) surfaces in order to create residual surface compressions to resist crack propagation in components such as aerofoils. Previously peening techniques have had problems with respect to achieving adequate treatment depths, speed of treatment and with respect to effectiveness. By the present method arrangement an electrical conductor (1, 41, 51) in the form of a wire is subject to electrical pulses to cause evaporation and subsequent breakdown with high power ultrasound (HPU) propagation in a volume of dielectric fluid towards a component and so peening. The electrical conductor (1, 41, 51) ensures that there is limited possibility of electrical discharge to the component (6, 46, 51) surface whilst the positioning of the wire (1, 41, 51) relative to the surface can be adjusted to achieve best effect particularly if reflector (5) devices are utilised to concentrate (HPU) pulse presentation to the component (6, 46, 56). Furthermore, the component (6, 46, 56) can be surface treated in order to provide protection from potentially damaging emissions from evaporation and electrical discharge to the wire (1, 41, 51)

Apparatus and method for electric spark peening of gas turbine components

Peening provides compression of component (6, 46, 56) surfaces in order to create residual surface compressions to resist crack propagation in components such as aerofoils. Previously peening techniques have had problems with respect to achieving adequate treatment depths, speed of treatment and with respect to effectiveness. By the present method arrangement an electrical conductor (1, 41, 51) in the form of a wire is subject to electrical pulses to cause evaporation and subsequent breakdown with high power ultrasound (HPU) propagation in a volume of dielectric fluid towards a component and so peening. The electrical conductor (1, 41, 51) ensures that there is limited possibility of electrical discharge to the component (6, 46, 51) surface whilst the positioning of the wire (1, 41, 51) relative to the surface can be adjusted to achieve best effect particularly if reflector (5) devices are utilised to concentrate (HPU) pulse presentation to the component (6, 46, 56). Furthermore, the component (6, 46, 56) can be surface treated in order to provide protection from potentially damaging emissions from evaporation and electrical discharge to the wire (1, 41, 51)

Electrical distribution networks

Safe operation of electrical power distribution systems necessitates consideration of the fault level in terms of the potential for electrical current flow upon an earth or other fault within the electrical power distribution system. Previously, electrical power systems have been analysed to provide theoretical fault levels values for different zones of an electrical power distribution system based upon a worse case scenario. However, existing electrical loads will in practice provide a more adaptable and higher fault level. By monitoring and identifying an I-V characteristic upon switching electrical load in practical operation an actual default level at particular nodes in a power distribution system is determinable . In such circumstances decisions with regard to the connectablilty of further electrical generators or loads at particular parts and zones of an electrical power distribution system can be quantified by reference to the actual fault level rather than the theoretical worse case scenario level and therefore avoid unnecessary upgrading of transmission equipment or denying access to the electrical power system