A novel performance model of losses of pump was presented,which allows an explicit insight into the losses of various friction pairs of pump.The aim is to clarify that to what extent the hydro-mechanical losses affect...A novel performance model of losses of pump was presented,which allows an explicit insight into the losses of various friction pairs of pump.The aim is to clarify that to what extent the hydro-mechanical losses affect efficiency,and to further gain an insight into the variation and distribution characteristics of hydro-mechanical losses over wide operating ranges.A good agreement is found in the comparisons between simulation and experimental results.At rated speed,the hydro-mechanical losses take a proportion ranging from 87% to 89% and from 68% to 97%,respectively,of the total power losses of pump working under 5 MPa pressure conditions,and 13% of full displacement conditions.Furthermore,within the variation of speed ranging from 48% to 100% of rated speed,and pressure ranging from 14% to 100% of rated pressure,the main sources of hydro-mechanical losses change to slipper swash plate pair and valve plate cylinder pair at low displacement conditions,from the piston cylinder pair and slipper swash plate pair at full displacement conditions.Besides,the hydro-mechanical losses in ball guide retainer pair are found to be almost independent of pressure.The derived conclusions clarify the main orientations of efforts to improve the efficiency performance of pump,and the proposed model can service for the design of pump with higher efficiency performance.展开更多
The article describes design peculiarities of the novel compact vacuum circuit breaker with rated voltage 40.5 kV. The design incorporates several novel technical solutions: polycarbonate support insulation, mono-sta...The article describes design peculiarities of the novel compact vacuum circuit breaker with rated voltage 40.5 kV. The design incorporates several novel technical solutions: polycarbonate support insulation, mono-stable magnetic actuator, labyrinth pulling insulator, core-type flexible contact and new compact vacuum interrupter (VI). Phases are encapsulated into silicone rubber providing required creepage distance and excellent tracking resistance. These novelties along with extensive modeling of the mechanical and electrical fields followed by design optimization resulted in weight reduction of more than 50% compared with alternatives available in the market. And this is in spite of built in sensors measuring: phase currents, zero-sequence current, phase voltages.展开更多
基金Project(2014CB046403)supported by the National Basic Research Program of ChinaProject(2013BAF07B01)supported by the National Key Technology R&D Program of China
文摘A novel performance model of losses of pump was presented,which allows an explicit insight into the losses of various friction pairs of pump.The aim is to clarify that to what extent the hydro-mechanical losses affect efficiency,and to further gain an insight into the variation and distribution characteristics of hydro-mechanical losses over wide operating ranges.A good agreement is found in the comparisons between simulation and experimental results.At rated speed,the hydro-mechanical losses take a proportion ranging from 87% to 89% and from 68% to 97%,respectively,of the total power losses of pump working under 5 MPa pressure conditions,and 13% of full displacement conditions.Furthermore,within the variation of speed ranging from 48% to 100% of rated speed,and pressure ranging from 14% to 100% of rated pressure,the main sources of hydro-mechanical losses change to slipper swash plate pair and valve plate cylinder pair at low displacement conditions,from the piston cylinder pair and slipper swash plate pair at full displacement conditions.Besides,the hydro-mechanical losses in ball guide retainer pair are found to be almost independent of pressure.The derived conclusions clarify the main orientations of efforts to improve the efficiency performance of pump,and the proposed model can service for the design of pump with higher efficiency performance.
文摘The article describes design peculiarities of the novel compact vacuum circuit breaker with rated voltage 40.5 kV. The design incorporates several novel technical solutions: polycarbonate support insulation, mono-stable magnetic actuator, labyrinth pulling insulator, core-type flexible contact and new compact vacuum interrupter (VI). Phases are encapsulated into silicone rubber providing required creepage distance and excellent tracking resistance. These novelties along with extensive modeling of the mechanical and electrical fields followed by design optimization resulted in weight reduction of more than 50% compared with alternatives available in the market. And this is in spite of built in sensors measuring: phase currents, zero-sequence current, phase voltages.