【Mechanical Equipment Technology Exchange Edition】Mechanical Equipment 【Daily Question】20191027

The losses within a turbine stage include nozzle losses, blade kinetic energy losses, residual velocity losses, blade height losses, fan-shaped losses, partial steam injection losses, frictional blowing losses, steam leakage losses, and wet steam losses.

Within a turbine stage, the main losses include nozzle loss, blade kinetic loss, residual velocity loss, blade height loss, fan loss, partial steam inlet loss, frictional blowing loss, steam leakage loss, and wet steam loss. Reasons for loss: 1) Nozzle losses and blade losses are caused by the mutual friction between the steam streams as they pass through the nozzles and blades, as well as by the friction between the steam streams and the surface of the blades. 2) The residual velocity loss refers to the fact that steam still possesses a certain velocity as it leaves the moving blades; this kinetic energy is not utilized in this stage, and thus it constitutes a loss for that stage. However, when the vapor stream flows to the next stage, its kinetic energy can be partially utilized by that stage. 3) Leaf height loss refers to the loss caused by vortices formed by the steam flow at the base and top of the nozzle and rotor blade cascade. 4) Fan-shaped loss refers to the fact that, due to the radial arrangement of the blades around the rim, the flow channel cross-section takes on a fan shape. As a result, the pitch, circumferential speed, and inlet angle vary along the blade height, which causes the steam flow to strike the blades and result in energy loss. Additionally, the steam flow generates radial movements that further consume its energy. 5) Some of the steam inlet losses are due to \"blowing\" losses that occur when the moving blades pass through the arc sections without nozzles, as well as gas rejection losses that occur when the moving blades move from the non-operating arc sections into the operating arc sections with nozzles. 6) Frictional blowing loss refers to the fact that the high-speed rotating impeller comes into friction with the steam surrounding it, causing this steam to rotate; as a result, part of the impeller’s useful work is consumed. Additionally, the vapor flow between the partition and the nozzle forms vortices due to centrifugal force, which also consumes the impeller’s useful work. 7) Steam leakage loss refers to the loss that occurs in a steam turbine due to pressure differences; as a result, part of the steam escapes through various static and dynamic clearances, rather than passing through the nozzles and blade passages, and thus does not contribute to power generation, leading to losses. 8) Wet steam loss refers to the situation in the low-pressure section of the turbine where the steam is in a wet steam state. The water contained in this wet steam not only expands to generate work, but it also consumes the kinetic energy of the steam flow; it further exerts a braking effect on the movement of the blades, thereby wasting useful work, and it also causes erosion of the blades.

The losses within a turbine stage mainly include nozzle losses, blade dynamic losses, residual velocity losses, blade height losses, fan losses, partial steam inlet losses, frictional blowing losses, steam leakage losses, and wet steam losses. 1) Nozzle loss and rotor blade loss are caused by the mutual friction between the steam flow as it passes through the nozzle and rotor blades, as well as the friction between the steam flow and the surface of the blades. 2) The residual velocity loss refers to the fact that steam still possesses a certain velocity as it leaves the moving blades; this kinetic energy is not utilized in this stage, and thus it constitutes a loss for that stage. However, when the vapor stream flows to the next stage, its kinetic energy can be partially utilized by that stage. 3) Leaf height loss refers to the loss caused by vortices formed by the steam flow at the base and top of the nozzle and rotor blade cascade. 4) Fan-shaped loss refers to the fact that, due to the radial arrangement of the blades around the rim, the flow channel cross-section takes on a fan shape. As a result, the pitch, circumferential speed, and inlet angle vary along the blade height, which causes the steam flow to strike the blades and result in energy loss. Additionally, the steam flow generates radial movements that further consume its energy. 5) Some of the steam inlet losses are due to \"blowing\" losses that occur when the moving blades pass through the arc sections without nozzles, as well as gas rejection losses that occur when the moving blades move from the non-operating arc sections into the operating arc sections with nozzles. 6) Frictional blowing loss refers to the fact that the high-speed rotating impeller comes into friction with the steam surrounding it, causing this steam to rotate; as a result, part of the impeller’s useful work is consumed. Additionally, the vapor flow between the partition and the nozzle forms vortices due to centrifugal force, which also consumes the impeller’s useful work. 7) Steam leakage loss refers to the loss that occurs in a steam turbine due to pressure differences; as a result, part of the steam escapes through various static and dynamic clearances, rather than passing through the nozzles and blade passages, and thus does not contribute to power generation, leading to losses. 8) Wet steam loss refers to the situation in the low-pressure section of the turbine where the steam is in a wet steam state. The water contained in this wet steam not only expands to generate work, but it also consumes the kinetic energy of the steam flow; it further exerts a braking effect on the movement of the blades, thereby wasting useful work, and it also causes erosion of the blades.

Energy loss caused by the flow of steam within the stage. These mainly include cascade losses, residual velocity losses, impeller friction losses, blowing losses, steam leakage losses, and wet steam losses.

The losses within a turbine stage are caused by the interaction of the following nine factors: nozzle losses, blade dynamic losses, residual velocity losses, blade height losses, fan-shaped losses, partial steam injection losses, frictional blowing losses, steam leakage losses, and wet steam losses.

Energy loss caused by the flow of steam within the stage. These mainly include cascade losses, residual velocity losses, impeller friction losses, blowing losses, steam leakage losses, and wet steam losses.

Within a turbine stage, the main losses include nozzle loss, blade kinetic loss, residual velocity loss, blade height loss, fan loss, partial steam inlet loss, frictional blowing loss, steam leakage loss, and wet steam loss.

That is, the inter-stage loss, the loss caused by the flow of fluid from the high-pressure impeller to the low-pressure impeller

Energy loss caused by the flow of steam within the stage. It mainly includes cascade losses, residual velocity losses, impeller friction losses, blowing losses, steam leakage losses, wet steam losses, etc

Within a turbine stage, the main losses include nozzle loss, blade kinetic energy loss, residual velocity loss, blade height loss, fan loss, partial steam inlet loss, frictional blowing loss, steam leakage loss, and wet steam loss