Voith hydrodinamic couplings use for the speed control of a centrifugal compressors

Abstract

Main reason for the use of speed con­trol is the saving of energy. Compared to other alternatives for oil flow and pressure control (inlet throttle, by­pass and inlet guide vane), speed control is by far the most economical control. It also allows a very wide regulation range, without causing increased wear, for example, as it occurs in throttle valves. Through the control possibility the compressor can be protected effectively against unpermissive operating ranges, for exam­ple, like the surge limit. If various ope­rating conditions (e.g. pressure varia­tion, mole weight, flushing, and flow adjustment) are to be realized, the speed control, in combination with other control possibilities, frequently offers the best solution. The speed control is also of valuable services to control the starting and stopping pro­cess. There is for example, the quick passage through the critical speed range. Last but not least, we would like to mention the flexibility. If system or process parameters are not yet known, not measurable or changes are to be expected later during opera­tion, final and exact adjustment is possible by speed control. For single-shaft turbocompressors, speed control is a very good alterna­tive for load adaptation. For this pur­pose more and more electric motors are used worldwide. For speed con­trol of these compressors with high power the Vorecon proved to be successful as hydrodynamic super­posing planetary gear. An operating experience from several project over a sufficient period of time confirm the forecasted availability and reliability