This paper investigates a continuous-flow heat engine based on evaporative cooling of hot air at reduced pressure. In this device, hot air is expanded in an expansion turbine, spray-cooled to saturation and re-compressed to ambient pressure in several stages with evaporative cooling between each stage. More work is available in expansion than is required during re-compression, so the device is a heat engine. The device provides a relatively cheap way to boost the power output of open-cycle gas turbines. The principal assumptions for the theoretical model developed herein are that air and water vapor are regarded as ideal gases with constant specific heat capacities. In the absence of losses associated with expansion and compression, the engine produces more power as the inlet temperature and the pressure ratio increase. The effects of irreversibilities are subsequently included in the expansion and compression stages, with realistic values used for the adiabatic efficiencies of turbine and fans. Purification and injection of water are also considered in the overall energy budget. As a typical result for the new engine, if the inlet air is the exhaust of a 56 MW open-cycle gas turbine, the adiabatic efficiencies of turbine and fan are 0.9, the pressure ratio is 6.5 and there is four-stage re-compression, then the power output is 20.5% that of the gas turbine. The power output is sensitive to the adiabatic efficiencies of turbine and fans.

References

References
1.
Barton
,
N. G.
, 2008, “
An Evaporation Heat Engine and Condensation Heat Pump
,”
ANZIAM J.
,
49
(
4
), pp.
503
524
.
2.
Batchelor
,
G. K.
, 1967,
An Introduction to Fluid Dynamics
,
Cambridge University Press
,
New York
.
3.
Reif
,
F.
, 1965,
Fundamentals of Statistical and Thermal Physics
,
McGraw-Hill
,
New York
.
4.
Çengel
,
Y. A.
, and
Boles
,
M. A.
, 1994,
Thermodynamics: An Engineering Approach
,
2nd ed
,
McGraw-Hill
,
New York
.
5.
Diesendorf
,
M.
, 2007,
Greenhouse Solutions with Sustainable Energy
,
University of NSW Press
,
New South Wales, Australia
.
6.
Naughten
,
B.
, 2003, “
Economic Assessment of Combined Cycle Gas Turbines in Australia: Some Effects of Microeconomic Reform and Technological Change
,”
Energy Policy
,
31
(
3
), pp.
225
245
.
7.
Al-Ibrahim
,
A. M.
, and
Varnham
,
A.
, 2010, “
A Review of Inlet Air-Cooling Technologies for Enhancing the Performance of Combustion Turbines in Saudi Arabia
,”
Appl. Therm. Eng.
,
30
(
14-15
), pp.
1879
1888
.
8.
Omidvar
,
B.
, 2001, “
Gas Turbine Inlet Air Cooling System
,”
Proceedings of the 3rd Annual Australian Gas Turbine Conference
, Melbourne, Australia.
9.
Romanov
,
V. V.
,
Movchan
,
S. N.
,
Chobenko
,
V. N.
,
Kucherenko
,
O. S.
,
Kutznetsov
,
V. V.
, and
Shevtsov
,
A. P.
, 2010, “
Performance and Application Perspectives of Air Heat Recovery Turbine Units
,”
Proceedings of the ASME Turbo Expo GT2010: Power for Land, Sea and Air
, Glasgow, UK.
10.
Zyryanov
,
Y. P.
, 2008, “
The UTZ Special Design Office for Construction of Gas Turbines Turns Fifty
,”
Therm. Eng.
,
55
(
8
), pp.
672
677
.
11.
Leyzerovich
,
A.
, 2002, “
New Benchmarks for Steam Turbine Efficiency
,” Power-Gen Worldwide, http://www.powergenworldwide.comhttp://www.powergenworldwide.com.
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