Table of Contents
Why is Carnot cycle not used in power plant?
Firstly, wet compression is difficult to achieve in real practice, and also a compressor would require much more work than a pump. ii. The heat addition process is isothermal in case of a Carnot cycle, whereas it is isobaric in a Rankine cycle.
What is a Carnot cycle What is its purpose?
Carnot cycle, in heat engines, ideal cyclical sequence of changes of pressures and temperatures of a fluid, such as a gas used in an engine, conceived early in the 19th century by the French engineer Sadi Carnot. It is used as a standard of performance of all heat engines operating between a high and a low temperature.
Why Rankine efficiency is less than that of Carnot efficiency?
The thermal efficiency of a Rankine cycle is lower then that of a Carnot cycle operating between the same temperature levels. This is primarily because of the fact that the energy transfer as heat in the boiler does not take place at constant temperature in the Rankine cycle.
What are the difficulties in Carnot cycle practice?
The Carnot cycle is reversible whereas the real engines are not reversible due to different reasons like friction, heat transfer to the insulating wall etc. In the Carnot cycle, all the reversible processes are extremely slow while real machines work faster.
Is Carnot cycle more efficient than Rankine cycle?
It has highest efficiency between two temperature differences. Rankine cycle has lower efficiency than Carnot cycle.
Why Carnot cycle is not suitable for steam power cycle?
However; the Carnot cycle is not a suitable model for steam power cycle since: The turbine has to handle steam with low quality which will cause erosion and wear in turbine blades. It is impractical to design a compressor that handles two phase.
What makes the Carnot cycle reversible?
This makes the Carnot cycle a completely reversible cycle that consists of the following process: 1. Reversible isothermal expansion in which the gas absorbs thermal energy qin and expands at a constant temperature Th. As the gas expands, work is done on its surroundings, as the cylinder head is moving.
How do you calculate the efficiency of the Carnot cycle?
To calculate the efficiency of the Carnot cycle it is necessary to determine the ratio of the work done (by the piston under expansion) to the total heat energy supplied to the cylinder to make it expand. The latter is denoted by Q1. The work done W is the difference between the heat supplied and that which is exhausted, W = Q 1 − Q 2.
Why is the Carnot cycle called the optimum cycle?
The Carnot cycle is the optimum cycle and all cycles attempt to reach this optimum. Maximum thermal efficiency is achieved by approaching the isothermal compression and expansion of the Carnot cycle, or by intercooling in compression and reheating in the expansion process.