What is a pressure turbine?

Back Pressure Turbines: a type of steam turbine that is used in connection with industrial processes where there is a need for low or medium pressure steam. The high pressure steam enters the back pressure steam turbine and while the steam expands – part of its thermal energy is converted into mechanical energy.

What are the differences between low pressure turbines and high pressure turbines?

The high pressure turbine is designed to efficiently extract work out of the high pressure steam as it initially enters the main propulsion turbines. The low pressure turbine is designed to efficiently extract work out of steam which is exhausting out of the high pressure turbine at a lower pressure.

What is the difference between back pressure turbine and condensing turbine?

Context in source publication two turbine types are condensing turbine and back pressure turbine. Figure 1 shows the difference between condensing and back pressure turbine.

What is low pressure turbine rotor?

The low pressure rotors, consisting of a series of alloy steel discs shrunk on a shaft and keyed in position, are machined from alloy steels forgings. Low pressure (LP) steam turbine disc cracking caused by stress corrosion is experienced worldwide in rotors used in both nuclear and fossil fuel power plants.

Why LP turbine is bigger than HP turbine?

As the high pressure steam comes out of the high pressure turbine losing its pressure to rotate the blades, its specific volume increases (Pressure decreases). So in order to handle fluid with high specific volume, low pressure turbine is made bigger in size.

Why high pressure steam is used in turbine?

They are made in a variety of sizes up to 1.5 GW (2,000,000 hp) turbines used to generate electricity. In general, steam contains high amount of enthalpy (espacially in the form of heat of vaporization). This implies lower mass flow rates compared to gas turbines.

What is a topping turbine?

Topping turbines receive high-pressure steam from new high-pressure boilers. The exhaust steam of the new turbine has the same pressure as the old boilers and is used to supply the old turbines.

What is a mixed or dual pressure turbine?

( iii ) Dual Pressure Turbine: A mixed or dual pressure turbine use two separate source of steam at different pressure. Typically used in nuclear reactors they are also used for heavy industrial operation with varying demand for load.

What are the advantages of a mixed flow turbine?

Mixed-flow turbines. A mixed-flow turbine of the Deriaz type uses swiveled, variable-pitch runner blades that allow for improved efficiency at part loads in medium-sized machines. The Deriaz design has proved useful for higher heads and also for some pumped storage applications ( see below ).

What are the different types of reaction turbines?

It increases the efficiency of the turbine. The reaction turbines may be classified into the following three types, depending upon the direction of flow of water through the wheel. Radial flow turbines. Axial flow turbines. Mixed flow turbines. 1. Radial Flow Turbines

What is a Deriaz turbine?

A mixed-flow turbine of the Deriaz type uses swiveled, variable-pitch runner blades that allow for improved efficiency at part loads in medium-sized machines. The Deriaz design has proved useful for higher heads and also for some pumped storage applications (see below).