Definition of Steam Turbine

Steam turbine is a machine that converts the energy conversion from steam heat energy into mechanical energy. Mechanical energy from the steam turbine is used to drive the equipment, such as electric generators, pumps, compressors and so on.

Working Principle Steam Turbine

To play the required number of times steam turbine steam generated from the boiler to the level of a certain state of steam, the steam then flows into the nozzle with the intent of changing the potential energy into kinetic energy. Vapor emanating from the nozzle directed to the blade or blades mounted curved around the turbine wheel and shaft which is a unit called roads or turbine rotor blade. Changes in the speed of steam because it hits the blades of the stimulation of the road so that the rotating blades of the turbine shaft. After the steam impingement blade path, the steam flows through the blade gap and diverted following the curve of the blade path. To take advantage of the kinetic energy as possible, arranged steam leaving the turbine with a speed as low as possible. To realize this, the blade path, more than one line. After the steam leaving the first blade, vapor velocity direction must be changed before entering the next blade path through the fixed blade with a fixed pressure.

                                               Figure 1 Chart Steam Turbine Parts

Classification of Steam Turbine

Steam turbines can be classified depending on the construction, the process of absorption of heat from steam, steam conditions entering and exiting the turbine and usage in the industry.

• Under Pressure Steam Turbine Login

a. Low-pressure turbine, the steam entering the turbine pressure between 1.2 to 2 ata (atm abs)

b. Intermediate pressure turbine, the steam entering the turbine pressure less than 4 ata

c. High-pressure turbine, the steam entering the turbine pressure above 40 ata

d. Very high pressure turbine, the steam entering the turbine pressure of 170 ata, with temperatures of 550 ° C or more

e. Critical pressure turbine, the steam entering the turbine pressure reached 225 ata.

• Based on the Structure of Cylinder Or Casing

a. Single cylinder turbine (single case)

b. Turbine tandem compound cylinders (tandem compound casing), where the turbines there are two or more cylinders that are on one shaft, usually used to drive electric generators

c. Cylinder cross compound turbine (cross compound casing), at which the turbine shaft arrangement has two or more that are not on one line and each shaft drives a generator of electricity.

Figure 2 Structure of Cylinder Based Turbine type or Casing

• Under the Direction of Steam Flow in Cylinder

a. Axial turbine, where the steam flow direction parallel to the axis of the turbine

b. Radial turbine, where the steam flow direction perpendicular to the axis of the turbine.

• Based Action Movement Against Vapor Blade

a. Impulse turbine, where the steam potential energy changes into kinetic energy only occurs at the nozzle or slit formed on the fixed blade

b. Reaction turbine, where the steam potential energy changes into kinetic energy occurs in fixed blade and the blade as well as a decrease in the potential energy takes place evenly

c. Steam turbine combination.

Figure 3 Impulse Turbine and the Turbine Blade Reaction

• Based Absorption Process Heat

a. Condensing steam turbine (condensing turbine), where the steam turbine output pressure is lower than atmospheric pressure (28 mmHg).

b. Back pressure steam turbine (back press turbine), where the steam turbine output is lower than the vapor pressure of entry, but is higher than atmospheric pressure

c. Extraction condensing steam turbine (extraction condensing turbine), where the steam turbine output there are two kinds of lower vapor pressure of the steam entering the turbine as the forth and vapor pressure lower than atmospheric pressure as the condensing turbine.

d. Steam turbine with reheat (reheat condensing turbine), where high-pressure steam turbine output is heated back to the boiler to further put pressure turbine medium or low pressure.

Figure 4 Various Turbine Based Absorption Process Heat

• Based on Use in Industry

a. Stationary steam turbine with a constant rotation, usually used to drive electric generators

b. Stationary steam turbine with variable rotation, boasanya used to drive pumps, compressors, blowers, etc.

c. Steam turbines are not stationary with variable rotation, usually used for the drive that is connected directly to the machine being played, such as locomotives, ships and so on