Although technological progress is very fast, one can often see situations where modern plants use principles that were discovered in past centuries. For example, the Rankine cycle, which was invented in the 19th century, is used in steam turbines even now.
Great inventor
The Rankine cycle was discovered by a Scottish physicist and engineer who lived and worked in the century before last. The invention was named after this great scientist, who was also one of the founders of technical thermodynamics.
Rankin William John was born in 1820 in the city of Edinburgh, where he studied for three years at the institute. However, the scientist could not finish this institution because of the difficult financial situation. But this did not prevent the gifted physicist from making a number of useful discoveries. So, in 1849, he received thermodynamic equations describing the relationship between mechanical energy and heat. He also built the theory of a steam engine and developed the basic principles that formed the basis for the operation of this unit. These provisions make up the process, which was given the name in honor of the scientist - the Rankine cycle.
Basic moments
This cycle is a theoretical expression of the work of thermodynamic processes that occur during the operation of steam power plants in the repetition mode. We can distinguish the following basic operations that are part of this cycle:
- the liquid evaporates at high pressure;
- water molecules in a gaseous state expand;
- wet steam condenses on the walls of the vessel;
- fluid pressure increases (returns to its original value).
It can be noted that the thermal efficiency for this cycle is in direct proportion to the initial temperature. Also, the effectiveness of this process is determined by the pressure values and the thermal state indicator at the initial position and at the output.
Steam turbine
This unit is a heat engine, as a result of which electricity is generated. The main nodes of this installation can be represented in the following list:
- the movable part, which consists of a rotor and blades attached to it;
- a stationary element having components such as a stator and nozzles.
The operation of the installation can be characterized in this way. Water in a gaseous state at high temperature and pressure is fed into the nozzle of the turbine. Here, at a supersonic speed, the potential energy of the vapor transforms into kinetic, while the particles of the vapor are driven. This, in turn, creates a gaseous stream that acts on the turbine blades. The rotation of these elements causes the rotor to move, resulting in the generation of electricity. Then, steam condensation occurs and it settles in a special chilled water receiver, from where the liquid is again pumped into the heat exchanger. Thus, the repetition of operations occurs, that is, the Rankine cycle is carried out.
This principle is used in installations at nuclear power plants, and it is also used in the operation of autonomous turbine plants for the production of electricity. This scheme is by far the most effective and economical. Installations operating on the principles of Rankine are distributed worldwide.