Tham khảo tài liệu 'lubrication fundamentals 2011 part 10', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Figure Reaction turbine with one velocity-compounded impulse stage. The first stage of this turbine is similar to the first velocity-compounded stage of Figure . However in the reaction blading of this turbine both pressure and velocity decrease as the steam flows through the blades. The graph at the bottom shows the changes in pressure and velocity through the various stages. Copyright 2001 by Exxon Mobil Corporation. All Rights Reserved. Figure Simple power plant cycle the working fluid here steam and water travels a closed loop in the typical power plant cycle. steam velocity this arrangement may be referred to as a 50 reaction turbine. The moving blades form the walls of moving nozzles that are designed to permit further expansion of the steam and to partially reverse the direction of steam flow which produces the reaction on the blades. The distinguishing characteristic of the reaction turbine is that a pressure drop occurs across both the moving and stationary nozzles or blades Figure . Normally reaction turbines employ a considerable number of rows of moving and stationary nozzles through which steam flows as its initial pressure is reduced to exhaust pressure. The pressure drop across each row of nozzles is therefore relatively small and steam velocities are correspondingly moderate permitting medium rotating speeds. Reaction stages are usually preceded by an initial velocity-compounded impulse stage as in Figure in which a relatively large pressure drop takes place. This results in a shorter less costly turbine. In the radial flow reaction or Ljungstrom turbine the steam does not flow axially through alternating rows of fixed and moving blades rather it flows radially through several rows of reaction blades. Alternate rows of blades move in opposite direction. They are fastened to two independent shafts that operate in opposite directions each shaft driving a load. After expansion in the turbine the steam usually exhausts to a .
