Best answer: When a heat engine is reversible?

What is reversed heat engine?

The reverse heat engine is a device that transfers energy from an object at a lower temperature to an object at a higher temperature by doing work on the system. … Refrigerators are reverse heat engines that pump energy out of the inside of the fridge and into the surrounding area by the way of an electric motor.

Can cops be less than1?

COP can be less than 1. … COP less than 1 is almost “unheard of”..but yes it is possible to have COP less than 1. Even though VARS has COP less than 1 ;it is still an energy efficient system because VARS uses low grade thermal energy as the energy input which can be waste heat from gas turbines ,geothermal energy etc.

Why is the heat engine not 100% efficient?

A heat engine is considered to be 100% efficient if only all the heat is converted into useful work or mechanical energy. Since heat engines cannot convert all the heat energy into mechanical energy, their efficiency can never be 100%.

Is Carnot engine 100 efficient?

In order to achieve 100% efficiency (η=1), Q2 must be equal to 0 which means that all the heat form the source is converted to work. The temperature of sink means a negative temperature on the absolute scale at which the temperature is greater than unity.

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What is the difference between heat engine and reversible heat engine?

The heat engine produces work by absorbing heat from source and liberating some heat to sink. The reversed heat engine transfers the heat from sink to the source with the help of external work..

Is the Ericsson cycle reversible?

This so-called modified Ericsson cycle is still a reversible process. With neon as refrigerant, the heat exchange and work extraction requirements are being studied. In a second step the influence of non-ideal heat exchange and non-ideal work extraction on the total cycle efficiency are being investigated.

Is irreversible engines have maximum efficiency?

All the reversible and irreversible engines have the same efficiency. Irreversible engines have maximum efficiency. All engines are designed as reversible in order to obtain maximum efficiency.

What makes a heat engine irreversible?

If instead, heating or cooling results from an energy transfer through a finite temperature difference such as Tn−T1>0 in Fig. 3(b), the process is irreversible. The energy transfer to the system and its entropy change are the same as in the previous paragraph.