Water is a scarce natural resource fundamental for human life. Power plant architects, engineers, and power utilities owners must do everything within their hands and technical capabilities to decrease the usage of water in power plants. This paper illustrates the research carried out by Pöyry Switzerland to reduce the water consumption on power and desalination combined cycle power plants, on which there are gas turbine evaporative cooling systems in operation. The present study analyzed the potential re-utilization and integration of the heat recovery steam generator (HRSG) blowdown into the evaporative cooling system. Relatively clean demineralized water, coming from the HRSG blowdown, is routed to a large water tank, where it is blended with distillate water to achieve the required water quality, before being used on the gas turbine evaporative cooling system. To prove the feasibility of the HRSG blowdown recycling concept, the Ras Al Khair Power and Desalination Plant owned and operated by the Saline Water Conversion Corporation (SWCC), located in the Eastern Province of the Kingdom of Saudi Arabia, was used as case study. Nevertheless, it is important to mention that the principles and methodology presented on this paper are applicable to every power and desalination combined cycle power plant making use of evaporative cooling. Sea water desalination is the primary source for potable water production on Saudi Arabia, with secondary sources being surface water and groundwater extracted from deep wells and aquifers. Saving water is of utmost importance for power plants located in locations where water is scarce, and as such, this paper aims to demonstrate that it is possible to decrease the water consumption of power and desalination combined cycle plants, on which evaporative cooling is used as gas turbine power booster, without having to curtail power production. The outcome of the study indicates that during the summer season, recycling the HRSG water blowdown into the gas turbine evaporative cooling systems would result on the internal water consumption for the gas turbine evaporative coolers decreasing by 545 ton/day, or 23.79%, compared with the original plant design which does not contemplate blowdown re-use. Using evaporative cooling results on an overall gain of 186 MW, or 10.27%, on gross power output, while CO2 emissions decrease by 46.8 ton CO2/h, which represents a 13.8% reduction compared with the case on which the evaporative cooling system is not in operation. A brief cost analysis demonstrated that implementation of the changes would result in a negligible increase of the operational expenses (OPEX) of the plant, i.e., implementation of the suggested modification has an unnoticeable impact on the cost of electricity (CoE). The payback of the project, due to limited operating hours on evaporative cooling every year, is of 12 years for a 30 year plant lifetime, while 2.22 M USD of extra-revenue on potable water sales are generated as a result of implementing the proposed solution. Although in principle this value is modest, the effect of government subsidies on water tariffs as well as political and strategic cost of water is not included on the calculations. In conclusion, the study results indicate that water recycling, and reduction of plant's water footprint for power and desalination combined cycle plants using evaporative cooling, is not only technically possible but commercially feasible.

References

References
1.
CDSI, 2014, “
Population Statistics
,” Central Department of Statistics and Information (CDSI) for the Kingdom of Saudi Arabia, Riyadh, Kingdom of Saudi Arabia, accessed Sept. 18, 2015, https://www.stats.gov.sa/en/797-0
2.
CDSI, 2016, “
Saudi Arabian Statistical Yearbook
,” Central Department of Statistics and Information (CDSI) for the Kingdom of Saudi Arabia, Riyadh, Kingdom of Saudi Arabia, accessed Sept. 18, 2015, https://www.stats.gov.sa/en/169
3.
Llamas
,
R.
, and
Custudio
,
E.
,
2003
,
Intensive Use of Groundwater: Challenges and Opportunities
,
A.A. Balkema Publishers
,
Lisse, The Netherlands
, p.
481
.
4.
Kajenthira
,
A.
,
Siddiqi
,
A.
, and
Anadon
,
L. D.
,
2012
, “
A New Case for Promoting Wastewater Reuse in Saudi Arabia: Bringing Energy Into the Water Equation
,”
J. Environ. Manage.
,
102
, pp.
184
192
.
5.
RCJY, 2016, “
Royal Commission Environmental Regulations (RCER)
,” Royal Commission of Jubail & Yanbu, Riyadh, Saudi Arabia, accessed May 19, 2016, https://www.rcjy.gov.sa/en-US/AboutUs/Environment/Pages/default.aspx
6.
Carmona
,
J.
,
2015
, “
Gas Turbine Evaporative Cooling Evalution for Lagos–Nigeria
,”
Appl. Therm. Eng.
,
89
, pp.
262
269
.
7.
Meher-Homji
,
C. B.
, and
Mee
,
T.
, III
,
2000
, “
Inlet Fogging of Gas Turbine Engines—Part A: Theory, Psychometrics and Fog Generation
,”
ASME
Paper No. 2000-GT-0307.
8.
Grindle
,
A. K.
,
Siddiqi
,
A.
, and
Anadon
,
L. D.
,
2015
, “
Food Security Amidst Water Scarcity: Insights on Sustainable Food Production From Saudi Arabia
,”
Sustainable Prod. Consumption
,
2
, pp.
67
78
.
9.
Abderrahman, W. A.,
2001
, “
Water Demand Management in Saudi Arabia
,”
Water Resources Management in Islam
,
N. I.
Faruqui
,
A. K.
Biswas
, and
M. J.
Bino
, eds.,
United Nations University Press
,
New York
, pp.
68
78
.
10.
FAO, 2016, “
Aquastat
,” Food and Agriculture Organization of the United Nations, Rome, Italy, accessed Sept. 18, 2015, http://www.fao.org/nr/water/aquastat/countries_regions/Profile_segments/SAU-WU_eng.stm
11.
Jonsson
,
M.
, and
Yan
,
J.
,
2005
, “
Humidified Gas Turbines—A Review of Proposed and Implemented Cycles
,”
Energy
,
30
(
7
), pp.
1013
1078
.
12.
Mertens
,
J.
,
Prieur-Vernat
,
A.
,
Corbisier
,
D.
,
Favrot
,
E.
, and
Boon
,
G.
,
2015
, “
Water Footprinting of Electricity Generated by Combined Cycle Gas Turbines Using Different Cooling Technologies: A Practitioner's Experience
,”
J. Cleaner Prod.
,
86
, pp.
201
208
.
13.
Byers
,
E. A.
,
Hall
,
J. W.
, and
Amezaga
,
J. M.
,
2014
, “
Electricity Generation and Cooling Water Use: UK Pathways to 2050 Byers
,”
Global Environ. Change
,
25
, pp.
16
30
.
14.
Hylkema
,
H.
, and
Read
,
A.
,
2014
, “
Reduction of Freshwater Usage of a Coal Fired Power Plant With CCS by Applying a High Level of Integration of All Water Streams
,”
Energy Proc.
,
63
, pp.
7187
7197
.
15.
Al-Ghasham
,
T. Y.
,
Clark
,
B.
,
Abu Al-Saud
,
A.
,
Al-Hajji
,
M. H.
,
Al-Muaibid
,
J. B.
, and
Gauthier
,
C.
,
2005
, “
Industrial Wastewater Treatment for Reuse, Assessment Study in a Saudi Aramco Facility
,”
Saudi Aramco J. Technol.
, pp.
52
60
.
16.
Al-Ansary
,
H. A.
,
Orfi
,
J. A.
, and
Ali
,
M. E.
,
2013
, “
Impact of the Use of a Hybrid Turbine Inlet Air Cooling System in Arid Climates
,”
Energy Convers. Manage.
,
75
, pp.
214
223
.
17.
De Sa
,
A.
, and
Al Zubaidy
,
S.
,
2011
, “
Gas Turbine Performance at Varying Ambient Temperature
,”
Appl. Therm. Eng.
,
31
(14–15), pp.
2735
2739
.
18.
Al-Ibrahim
,
A. M.
, and
Varnham
,
A.
,
2010
, “
A Review of Inlet Air Cooling Technologies for Enhancing Its Performance of Combustion Turbines in Saudi Arabia
,”
Appl. Therm. Eng.
,
30
(14–15), pp.
1879
1888
.
19.
Meher-Homji
,
C. B.
, and
Mee
,
T.
, III
,
2000
, “
Inlet Fogging of Gas Turbine Engines—Part B: Practical Considerations, Control and O&M Aspects
,”
ASME
Paper No. 2000-GT-0308.
20.
Dawoud
,
B.
,
Zurigat
,
Y. H.
, and
Bortmany
,
J.
,
2005
, “
Thermodynamic Assessment of Power Requirements and Impact of Different Gas Turbines Inlet Air Cooling Techniques at Two Different Locations in Oman
,”
Appl. Therm. Eng.
,
25
(11–12), pp.
1579
1598
.
21.
GE Corporate, 1997, “
GE Handbook of Industrial Water Treatment Systems
,” General Electric Company, Trevose, PA, accessed Oct. 6, 2015, http://www.gewater.com/handbook/boiler_water_systems/ch_13_blowdowncontrol.jsp
22.
Johnson
,
R. S.
, and P. E., Sr.,
1988
, “
The Theory and Operation of Evaporative Coolers for Industrial Gas Turbine Installations
,”
J. Eng. Gas Turbines Power
,
111
(2), pp. 327–334.
23.
WHO,
2011
,
Guidelines for Drinking-Water-Quality
,
4th ed.
,
World Health Organization
,
Geneva, Switzerland
.
24.
Nalco Company,
2009
,
Nalco Water Handbook
,
3rd ed.
,
McGraw-Hill Education
, New York, pp.
270
278
.
25.
Matches, 2014, “
Matche's Tank Cost Estimation Software
,” Matches, Edmond, OK, accessed Jan. 28, 2017, http://www.matche.com/equipcost/Tank.html
26.
WATEREUSE ASSOCIATION, 2012, “
Seawater Desalination Costs
,” Watereuse Association, Alexandria, VA, accessed Aug. 25, 2016, https://watereuse.org/wp-content/uploads/2015/10/WateReuse_Desal_Cost_White_Paper.pdf
27.
Arab News, 2015, “
Water Tariff to Rise 50% Next Month
,” Saudi Research & Publishing Company, Jeddah, Saudi Arabia, accessed Aug. 24, 2016, http://www.arabnews.com/saudi-arabia/news/829286
28.
Ouda, O. K. M., 2013, “
Review of Saudi Arabia Municipal Water Tariff
,”
World Environment
,
3
(2), pp. 66–70.
29.
Arab News, 2016, “
KSA's Water Consumption Surpasses Global Average
,” Saudi Research & Publishing Company, Jeddah, Saudi Arabia, accessed Aug. 25, 2016, http://www.arabnews.com/saudi-arabia/news/879801
30.
IPCC, 2006, “
2006 IPCC Guidelines for National Greenhouse Gas Inventories
,” Intergovernmental Panel on Climate Change, Geneva, Switzerland, accessed Aug. 25, 2016, http://www.ipcc-nggip.iges.or.jp/public/2006gl/
You do not currently have access to this content.