Impulse Reverse Combined Turbine

The high pressure cylinder is an impulse turbine and the low cylinder is a double flow reaction turbine. This turbine gives full play to the advantages of impulse stage and reaction stage. The disadvantages are avoided and the performance of steam turbine is improved.

Impulse-reaction hybrid steam turbine is a widely used structure of two-cylinder main steam turbine used in ships at present. High pressure steam turbines use impulse stages because:

1, the blade is too short time can use local steam intake to increase the height of the blade.

2, the relative value of radial clearance of the working cascade is large, which can reduce the internal leakage loss and improve the efficiency of the stage.

Low pressure steam turbines use reaction stages because:

1, high blade, large reaction can avoid negative reaction at the root;

2, the relative value of radial clearance is small, can be less internal leakage loss;

3, the steam flow speed in the reaction stage is low, which can reduce the erosion of water droplets in the wet steam to the working blade.

In addition, the impulse stage is used as a regulating stage or in order to improve efficiency, so that the impulse stage has a small degree of reaction can also be called the impulse-reaction hybrid turbine.