Effective temperature and performance characteristics of heat engines

Year 2018, Volume: 21 Issue: 3, 158 - 172, 01.09.2018

Mahmoud Huleihil

https://doi.org/10.5541/ijot.414698

Abstract

For a heat engine working between
two heat reservoirs, a hot reservoir at high temperature T_H
and a cold reservoir at low temperature T_L, an effective
temperature and an effective efficiency are introduced.

The effective temperature is defined
as the square root of the ratio between the net work output of the heat engine w_net
and the SOT function (a new function introduced in this article).
The SOT function is defined as the negative of the cyclic
integral of the heat transfer change divided by the square of the temperature.

The effective efficiency of the heat
engine is defined (a novel definition) as one minus the ratio between the low
temperature and the effective temperature.

The effective temperature and the
effective efficiency are worked out in details for the Carnot heat engine and
the air standard cycles (Otto, Brayton, Stirling, and Ericsson).

It was found for the considered
cycles that the effective temperature is given by the expression () 



















and the effective
efficiency is given by the expression () 

for all the considered
cycles.

The importance of these two proposed
measures is twofold: educational and they could be used as a quick tool by the
designer.

Keywords

heat engine, temperature, performance characteristics

References

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