Why Carnot cycle is not possible?

Why Carnot cycle is not possible?

Carnot cycles are not encountered in reality since achieving isothermal heat transfer is very difficult (needs very large heat exchangers and long time). Also process 3-4 requires a pump or compressor that can handle two phase mixture (liquid and vapor) which is impractical.

What is the Carnot efficiency?

Carnot efficiency is the maximum efficiency that a heat engine may have operating between the two temperatures (Figure 2-7). Figure 2-7. Carnot process efficiency. The Carnot efficiency has little practical value. It is a maximum theoretical efficiency of a hypothetical engine.

How efficient is a Carnot engine?

From the Carnot Efficiency formula, it can be inferred that a maximum of 64% of the fuel energy can go to generation. To make the Carnot efficiency as high as possible, either Thot should be increased or Tcold (temperature of heat rejection) should be decreased.

Is Carnot engine real?

Any engine using the Carnot cycle, which uses only reversible processes (adiabatic and isothermal), is known as a Carnot engine. Any engine that uses the Carnot cycle enjoys the maximum theoretical efficiency.

Is Carnot engine a heat engine?

A Carnot heat engine is a theoretical engine that operates on the Carnot cycle. The basic model for this engine was developed by Nicolas LĂ©onard Sadi Carnot in 1824. In the process of going through this cycle, the system may perform work on its surroundings, thereby acting as a heat engine.

What is Carnot principle?

Carnot’s theorem states that all heat engines between two heat reservoirs are less efficient than a Carnot heat engine operating between the same reservoirs. Every Carnot heat engine between a pair of heat reservoirs is equally efficient, regardless of the working substance employed or the operation details.

How do you pronounce Carnot engine?

  1. Phonetic spelling of Carnot. k-uh-er-n-oh.
  2. Meanings for Carnot. He is a French physicist who founded thermodynamics.
  3. Synonyms for Carnot. Sadi Carnot.
  4. Examples of in a sentence.
  5. Translations of Carnot.

What is PV and TS diagram?

As described on the work slide, the area under a process curve on a p-V diagram is equal to the work performed by a gas during the process. On the right of the figure we have plotted the temperature versus the entropy of the gas. This plot is called a T-s diagram.

What is reverse Carnot cycle?

Reversing the Carnot cycle does reverse the directions of heat and work interactions. A refrigerator or heat pump that operates on the reversed Carnot cycle is called a Carnot refrigerator or a Carnot heat pump.

What is the difference between Carnot cycle and reversed Carnot cycle?

Reversed Carnot cycle is the same as that of the conventional Carnot Cycle except for the direction of the processes.

Why is the reversed Carnot cycle impractical?

It is imaginary cycle can not be created we discuss in limitation points why we can not used in actually. Practically, the reversed Carnot cycle cannot be used for refrigeration purpose as the isentropic process requires very high speed operation, whereas the isothermal process requires very low speed operation.

Why is the Carnot cycle important?

The Carnot engine — or the Carnot cycle — is important because it describes a heat engine that uses reversible processes that can be handled theoretically. Then we could use the real heat engine to power a Carnot cycle heat pump. During this isothermal expansion heat Qh flows into the gas from the hot temperature Th.

What are the limitations of reversed Carnot cycle?

LIMITATIONS OF REVERSE CARNOT CYCLE isentropic process is possible if it very fast. This alternate combination of very fast, very slow, very fast and very slow is not possible to achieve in actual practice and these are thus the limitations of this cycle.

What is reversed Brayton cycle?

A Brayton cycle that is driven in reverse direction is known as the reverse Brayton cycle. Its purpose is to move heat from colder to hotter body, rather than produce work. This cycle is also known as the gas refrigeration cycle or Bell Coleman cycle.

What are the limitation of reverse Carnot cycle using Vapour and gas as refrigerant?

Drawbacks of using Air as Refrigerant in Reverse Carnot cycle: Due to isentropic compression, very high pressure and due to isothermal heat rejection very high volume of gas is developed. Isothermal heat transfer with gas is not possible practically due to the very small specific heat of the gas.

What is the function of flash chamber?

A flash chamber is a device which separates liquid from vapors. Only liquid is then passed to evaporator and the vapors will be passed to the compressor directly. This flash chamber between the condenser and evaporator is known as flash intercooling.

What is flash gas removal?

Flash gas removal using flash tank. It is mentioned above that one of the problems with high temperature lift applications is the high quality of vapour at the inlet to the evaporator. This vapour called as flash gas develops during the throttling process.

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