Table of Contents
- 1 Why Carnot Vapour power cycle is not used as ideal cycle for steam power plant?
- 2 Is the Carnot cycle suitable as an ideal cycle for all power producing cyclic devices?
- 3 Where is Carnot cycle used?
- 4 Why is Carnot more efficient than Rankine?
- 5 What are the limitations of the Carnot cycle?
- 6 Which is the best cycle for steam power plant?
Why Carnot Vapour power cycle is not used as ideal cycle for steam power plant?
We have seen that Carnot cycle is not the theoretical/ideal cycle for steam turbine power plant because of the difficulty of pumping a mixture of water and steam and delivering it as saturated water only.
Why does Rankine cycle is used rather than Carnot cycle in power plant?
Heat addition in power plants is at constant pressure whereas it is constant temperature process in Carnot Cycle which is not easily achievable. That is why we don’t go for Carnot cycle in power plants but use a more practical Rankine Cycle.
What is the difference between Carnot and Rankine cycle and why not use Carnot as the model cycle for powerplants?
Carnot cycle is an ideal cycle for heat engine which gives highest efficiency between given temperature difference but it is a theoretical cycle and actually no engine works on it. Rankine cycle is an ideal cycle of vapor or steam power generation. It gives highest efficiency between given temperature difference.
Is the Carnot cycle suitable as an ideal cycle for all power producing cyclic devices?
Practically, it is very difficult to add or reject heat to or from working fluid at constant temperature. But it is comparatively easy to add or reject heat to or from the working fluid at constant pressure. So, Carnot cycle is not used as an idealized cycle for steam power plants.
Why is the Carnot cycle used in large power plants?
The Carnot efficiency is valid for reversible processes. These processes cannot be achieved in real cycles of power plants. The Carnot efficiency dictates that higher efficiencies can be attained by increasing the temperature of the steam. This feature is also valid for real thermodynamic cycles.
Why Rankine cycle is less efficient than the Carnot cycle?
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.
Where is Carnot cycle used?
heat engines
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.
Is the Carnot cycle suitable as an ideal cycle?
The Carnot cycle consists of the following four processes: A reversible isothermal gas expansion process. In this process, the ideal gas in the system absorbs qin amount heat from a heat source at a high temperature Thigh, expands and does work on surroundings….T-S Diagram.
| Process | ΔT | ΔS |
|---|---|---|
| IV | Thigh−Tlow | 0 |
| Full Cycle | 0 | 0 |
In which power power plant Rankine cycle is used in?
The Rankine cycle or Rankine Vapor Cycle is the process widely used by power plants such as coal-fired power plants or nuclear reactors. In this mechanism, a fuel is used to produce heat within a boiler, converting water into steam which then expands through a turbine producing useful work.
Why is Carnot more efficient than Rankine?
In the Rankine cycle, the mean temperature at which heat is supplied is less than the maximum temperature, so that the efficiency is less than that of a Carnot cycle working between the same maximum and minimum temperatures. Moreover, The reason lies in the nature of the Rankine cycle and that of the fluid.
Why is Carnot cycle used?
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 is the Carnot cycle utilized in large power plants?
What are the limitations of the Carnot cycle?
Firstly, carnot cycle involves transition from an isothermal process to an adiabatic process. This is impossible to attain practically because isothermal is very slow and adiabatic is very fast. The heat exchange in carnot cycle is isothermal which needs the working fluid to either phase change or the process be extremely slow.
Why is the Carnot vapour cycle not suitable for steam power plant?
Carnot Vapour cycle is not suitable for steam power plant because in Carnot Vapour cycle at the end of condensation process we get a two phase mixture and next is the compression process where it is impossible to compress a mixture in two phase. For better understanding you can check this link I hope it helps you.
Why is the Carnot cycle an idealization of the heat engine cycle?
In order to approach the Carnot efficiency, the processes involved in the heat engine cycle must be reversible and involve no change in entropy. This means that the Carnot cycle is an idealization, since no real engine processes are reversible and all real physical processes involve some increase in entropy.
Which is the best cycle for steam power plant?
However ideal cycle for steam power plant is Rankine cycle. Carnot Vapour cycle is not suitable for steam power plant because in Carnot Vapour cycle at the end of condensation process we get a two phase mixture and next is the compression process where it is impossible to compress a mixture in two phase.