scholarly journals A VORTEX DROP STRUCTURE AS DEAERATION SYSTEM FOR A SUBMARINE OUTFALL PIPELINE

2018 ◽  
pp. 16
Author(s):  
Rolando García
Keyword(s):  
Power Plants ◽  
Water Discharge ◽  
Thermal Power ◽  
Cooling Water ◽  
Air Entrainment ◽  
Return Flow ◽  
World Bank Group ◽  
Discharge System ◽  
Under Construction ◽  
Drop Structure

Use of submarine outfall pipelines became more common since World Bank Group issued a new guideline for maximum emissions levels for thermal power plants in 1998 (van Dijk, 2005). The more restrictive levels for temperature increase at the receiving water, requires outfall systems to conduct the water down to greater depths to achieve the required dilution standard. However, air entrainment control into outfall pipes could be challenging, especially for discharges with high flowrates for which conventional deaeration chambers become too large. The problem could turn more difficult in coastal shelf areas at seismic zones, where the hydraulic height of the incoming flow must be effectively controlled and the design not only has to pursue hydraulic objectives but also stability requirements for these massive structures subjected to relevant seismic thrusts. A vortex drop structure was designed for the cooling water discharge system of a thermal power plant in Mejillones Bay, Chile. The structure addresses the elevation difference between the return flow pipe and the ocean outfall pipelines while adhering to the spatial restrictions at the project site. Energy dissipation as well as limitation of air entrainment into the outfall pipelines were critical design considerations. Tests where done on a 1:12.5 scale (Froude) physical model. Prototype structure is under construction. Operation is planned to start on mid-2018.

Numerical Study of Discharged Heat Water Effect on Aquatic Environment From Coastal Thermal Power Plant by Using Two Water Discharged Pipes

2018 ◽  
Vol 7 (2) ◽  
pp. 97-116
Author(s):  
Alibek Issakhov
Keyword(s):  
Power Plant ◽  
Aquatic Environment ◽  
Thermal Power Plant ◽  
Power Plants ◽  
Numerical Study ◽  
Water Discharge ◽  
Thermal Power ◽  
Numerical Results ◽  
Stratified Medium ◽  
Discharge System

The article presents a numerical study of the thermal load on the aquatic environment by using two water discharge pipes under various operational capacities of thermal power plant. It is solved by the Navier-Stokes and temperature transport equations for an incompressible fluid in a stratified medium. The aim of this article is to improve the existing water discharge system for reduce the heat load on the reservoir-cooler of the thermal power plants operation (Ekibastuz SDPP-1). In this article, thermal pollution using only two water discharge pipes, using the existing one and building only one additional in the eastern part of the reservoir-cooler is numerically simulated. The numerical method is based on the projection method, which was approximated by the finite volume method. The obtained numerical results of three-dimensional stratified turbulent flow for two water discharge pipes under various operational capacities of the thermal power plant were compared with experimental data and with the numerical results for one water discharge pipe.

Biological Monitoring of Thermal Effects of Cooling Water Discharges from Danish Power Plants

1983 ◽  
Vol 15 (10) ◽  
pp. 89-99
Author(s):  
Bo Møller ◽  
K I Dahl-Madsen
Keyword(s):  
Water Quality ◽  
Biological Monitoring ◽  
Benthic Community ◽  
Power Plants ◽  
Water Discharge ◽  
Cooling Water ◽  
Temperature Fields ◽  
Planning System ◽  
Excess Temperature ◽  
Water Entrainment

In the years from 1970-1982 52 site studies and monitoring studies have been carried out at major existing and planned power plants. The results from the studies have been used in a planning system for water quality. This planning system, which is water quality related, is described in this paper. An important part of the planning system is the description of size and distribution of excess temperature fields and the related biological conditions. In the biological monitoring, emphasis is placed on the benthic community as more vulnerable to the cooling water discharge. The studies have shown that the excess temperature field within the 1-2° isotherm can produce measurable changes in the benthic community. The temperature effect in the pelagic zone is marginal, however, some effects are seen at sites with a deep water intake of nutrient rich water. Entrainment of fish and Zooplankton can be important in bays and estuaries.

Thermal Effects of Nuclear Power Stations

1974 ◽  
Vol 9 (1) ◽  
pp. 188-195
Author(s):  
G. Bethlendy
Keyword(s):  
Thermal Effects ◽  
Nuclear Power ◽  
Power Plants ◽  
Nuclear Power Plants ◽  
Sea Water ◽  
Waste Heat ◽  
Thermal Power ◽  
Cooling Water ◽  
District Heating ◽  
Before And After

Abstract Even with the latest technology, more than 60% of the heat produced by any thermal engine - whether the fuel is coal, oil, gas or uranium - must be taken back into the environment by cooling water or exhaust gas. For economical reasons, the usual means of disposing of the “waste” heat from a thermal-power plant is to pump river, lake or sea water through the parts of the plant concerned. Nuclear power plants use their heat as efficiently as older thermal plants, 30–33%. Modern thermal plants, however work with as high as 40% efficiency, and release about 10–13% of their total fuel-heat into the air through the stack. As a result of the combination of all these factors, nuclear power plants release about 68–70% of total input heat into the cooling water. In practice this means that the plant must be able to draw upon a source of cooling water which is large enough, which flows quickly or is cold enough not to be seriously effected by the return of warmed-up water from the power station. Where this is not possible, it may be necessary to build relatively expensive cooling ponds and/or towers so that the heat is also released to the air rather than only to a local body of water. The thermal effects could be detrimental or beneficial depending on the utilization of the water body. At the present time the utilities are aware of these problems and very extensive aquatic studies are being made before and after the construction of the plants. Some beneficial uses of waste heat are being sought via research and demonstration projects (e.g. in agriculture, aquaculture, district heating, etc.).

Numerical Study of the Discharged Heat Water Effect on the Aquatic Environment from Thermal Power Plant by using Two Water Discharged Pipes

2017 ◽  
Vol 18 (6) ◽  
pp. 469-483 ◽  
Author(s):  
Alibek Issakhov
Keyword(s):  
Power Plant ◽  
Aquatic Environment ◽  
Thermal Power Plant ◽  
Numerical Study ◽  
Water Discharge ◽  
Thermal Power ◽  
Numerical Results ◽  
Stratified Medium ◽  
Water Effect ◽  
Discharge System

AbstractThe paper presents a numerical study of the discharged heat water effect on the aquatic environment from the thermal power plant by using two water discharged pipes. It is solved by the Navier–Stokes and temperature transport equations for an incompressible fluid in a stratified medium. The aim of this study is to improve the existing water discharge system to reduce the heat load on the reservoir-cooler of the thermal power plants operation (Ekibastuz SDPP-1). In this study thermal pollution to the reservoir-cooler using only two water discharged pipes as so using the existing one and building only one additional in the eastern part of the reservoir-cooler is numerically simulated. The numerical method is based on the projection method which was approximated by the finite volume method. The numerical solution of the equation system is divided into four stages. The algorithm is parallelized on a high-performance computer. The obtained numerical results of three-dimensional stratified turbulent flow for two water discharged pipes of the thermal power plant were compared with experimental data and with numerical results for one water discharged pipe. General thermal load in the reservoir-cooler decreases comparing one water discharged pipe and revealed qualitatively and quantitatively approximately the basic laws of hydrothermal processes occurring in the reservoir-cooler can be seen that from numerical simulations where two water discharged pipes were used.

The Study on Water Conservation in Thermal Power Plants

2014 ◽  
Vol 675-677 ◽  
pp. 1716-1720 ◽  
Author(s):  
Jian Lei Zhou ◽  
Yu Yun Fu
Keyword(s):  
Water Conservation ◽  
Power Plants ◽  
Thermal Power ◽  
Water System ◽  
Cooling Water ◽  
Working Fluid ◽  
Feed Water ◽  
Thermal Power Plants ◽  
Transfer Energy ◽  
Circulating Cooling Water

As the main working fluid pair to transfer energy and cool down the equipment, water is used in a large amount in thermal power plants. It will promote water conservation and resource recycling if the water use is managed effectively in production and the wastewater, which come from circulating cooling water system, the pretreatment in boiler feed water preparation system, desalination system and condensate polishing system, is disposed and recycled well.

scholarly journals Simulations of anthropogenic bromoform indicate high emissions at the coast of East Asia

2021 ◽  
Vol 21 (5) ◽  
pp. 4103-4121
Author(s):  
Josefine Maas ◽  
Susann Tegtmeier ◽  
Yue Jia ◽  
Birgit Quack ◽  
Jonathan V. Durgadoo ◽  
...  
Keyword(s):  
Water Treatment ◽  
Southeast Asia ◽  
East Asia ◽  
General Circulation ◽  
Power Plants ◽  
Water Discharge ◽  
Cooling Water ◽  
The Yellow Sea ◽  
Boreal Summer ◽  
The Tropics

Abstract. Bromoform is the major by-product from chlorination of cooling water in coastal power plants. The number of power plants in East and Southeast Asian economies has increased rapidly, exceeding mean global growth. Bottom-up estimates of bromoform emissions based on few measurements appear to under-represent the industrial sources of bromoform from East Asia. Using oceanic Lagrangian analyses, we assess the amount of bromoform produced from power plant cooling-water treatment in East and Southeast Asia. The spread of bromoform is simulated as passive particles that are advected using the three-dimensional velocity fields over the years 2005/2006 from the high-resolution NEMO-ORCA0083 ocean general circulation model. Simulations are run for three scenarios with varying initial bromoform concentrations based on the range of bromoform measurements in cooling-water discharge. Comparing the modelled anthropogenic bromoform to in situ observations in the surface ocean and atmosphere, the two lower scenarios show the best agreement, suggesting initial bromoform concentrations in cooling water to be around 20–60 µg L−1. Based on these two scenarios, the model produces elevated bromoform in coastal waters of East Asia with average concentrations of 23 and 68 pmol L−1 and maximum values in the Yellow Sea, Sea of Japan and East China Sea. The industrially produced bromoform is quickly emitted into the atmosphere with average air–sea flux of 3.1 and 9.1 nmolm-2h-1, respectively. Atmospheric abundances of anthropogenic bromoform are derived from simulations with the Lagrangian particle dispersion model FLEXPART based on ERA-Interim wind fields in 2016. In the marine boundary layer of East Asia, the FLEXPART simulations show mean anthropogenic bromoform mixing ratios of 0.4–1.3 ppt, which are 2–6 times larger compared to the climatological bromoform estimate. During boreal winter, the simulations show that some part of the anthropogenic bromoform is transported by the northeasterly winter monsoon towards the tropical regions, whereas during boreal summer anthropogenic bromoform is confined to the Northern Hemisphere subtropics. Convective events in the tropics entrain an additional 0.04–0.05 ppt of anthropogenic bromoform into the stratosphere, averaged over tropical Southeast Asia. In our simulations, only about 10 % of anthropogenic bromoform is outgassed from power plants located in the tropics south of 20∘ N, so that only a small fraction of the anthropogenic bromoform reaches the stratosphere. We conclude that bromoform from cooling-water treatment in East Asia is a significant source of atmospheric bromine and might be responsible for annual emissions of 100–300 Mmol of Br in this region. These anthropogenic bromoform sources from industrial water treatment might be a missing factor in global flux estimates of organic bromine. While the current emissions of industrial bromoform provide a significant contribution to regional tropospheric budgets, they provide only a minor contribution to the stratospheric bromine budget of 0.24–0.30 ppt of Br.

scholarly journals Economic Consequences of Cooling Water Insufficiency in the Thermal Power Sector under Climate Change Scenarios

2018 ◽  
Author(s):  
Qian Zhou ◽  
Naota Hanasaki ◽  
Shinichiro Fujimori
Keyword(s):  
Climate Change ◽  
Power Plants ◽  
Thermal Power ◽  
Cooling Water ◽  
Economic Consequences ◽  
Asia Pacific ◽  
Climate Change Scenarios ◽  
Power Sector ◽  
Industrial Sectors ◽  
Impacts Of Climate Change

Abstract: Currently, thermal power is the largest source of power in the world. Although the impacts of climate change on cooling water sufficiency in thermal power plants have been extensively assessed globally and regionally, their economic consequences have seldom been evaluated. In this study, the Asia-Pacific Integrated Model Computable General Equilibrium model (AIM/CGE) was used to evaluate the economic consequences of projected future cooling water insufficiency on a global basis, which was simulated using the H08 global hydrological model. This approach enabled us to investigate how the physical impacts of climate change on thermal power generation influence economic activities in regions and industrial sectors. To account for the uncertainty of climate change projections, five global climate models and two representative concentration pathways (RCPs 2.6 and 8.5) were used. The ensemble-mean results showed that the global gross domestic product (GDP) loss in 2070–2095 due to cooling water insufficiency in the thermal power sector was −0.21% (−0.12%) in RCP8.5 (RCP2.6). Among the five regions, the largest GDP loss of −0.57% (−0.27%) was observed in the Middle East and Africa. Medium-scale losses of −0.18% (−0.12%) and −0.14% (−0.12%) were found in OECD90 (the member countries of the Organization for Economic Co-operation and Development as of 1990) and Eastern Europe and the Former Soviet Union, respectively. The smallest losses of −0.05% (−0.06%) and −0.09% (−0.08%) were found in Latin America and Asia, respectively. The economic impact of cooling water insufficiency was non-negligible and should be considered as one of the threats induced by climate change.

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