Effect of Different Heat Rejection Scenarios on Cooling Tower Plume Dispersion

2013 ◽  
Vol 448-453 ◽  
pp. 213-216
Author(s):  
Rui Ping Guo ◽  
Chun Lin Yang ◽  
Bing Lan ◽  
Chun Ming Zhang
Keyword(s):  
Cooling Tower ◽  
Plume Dispersion ◽  
Impact Model ◽  
Length Frequency ◽  
Plume Height ◽  
Heat Rejection ◽  
Variation Trend ◽  
The Impact

This impact of heat rejection on cooling tower plume dispersion was studied in this paper by applied SACTI (Seasonal Annual Cooling Tower Impact) model. In order to analyze the impact of heat rejection (HR), we set five scenarios including observed, HR decrease 5% (HR-5) and 10% (HR-10), and increase 5% (HR+5) and 10% (HR+10). Results showed that plume length frequency, plume height frequency and plume radius frequency will present different variation trend when heat rejection increase and decrease scenarios. On the whole, the plume character parameter will decrease as heat rejection decrease, but will increase as heat rejection increasing.

Response Analysis of Cooling Tower Plume Dispersion to the Release Height

2013 ◽  
Vol 316-317 ◽  
pp. 590-593
Author(s):  
Rui Ping Guo ◽  
Chun Lin Yang ◽  
Chun Ming Zhang
Keyword(s):  
Environmental Impact ◽  
Impact Assessment ◽  
Environmental Impact Assessment ◽  
Cooling Tower ◽  
Response Analysis ◽  
Plume Dispersion ◽  
Length Frequency ◽  
Plume Height ◽  
Release Height ◽  
Relative Change

The SACTI model (Seasonal Annual Cooling Tower Impact) as the environmental impact assessment of cooling tower was applied in this paper, which was used to simulate the plume characters under different cooling tower heights. The results showed that the plume length, plume height and plume radius presented noticeable differences with variances of different distances and wind directions under different cooling tower heights. The comparisons of differences of plume characters indicated that the relative change of plume length frequency displayed obvious decreased trend with increased distance when distance was greater than 500m, and that of plume height frequency appeared parabolic curve with increased distance. The relative change of plume radius frequency expressed totally descended trend.

Impact of Relative Humidity on Cooling Tower Plume Dispersion

2013 ◽  
Vol 807-809 ◽  
pp. 168-171
Author(s):  
Rui Ping Guo ◽  
Chun Lin Yang ◽  
Chun Ming Zhang ◽  
Bing Lan
Keyword(s):  
Relative Humidity ◽  
Environmental Impact ◽  
Impact Assessment ◽  
Wind Direction ◽  
Cooling Tower ◽  
Plume Dispersion ◽  
Plume Height ◽  
Different Seasons ◽  
Change Trend ◽  
Dispersion Character

The SACTI model (Seasonal Annual Cooling Tower Impact) as the environmental impact assessment of cooling tower was applied in this paper, which was used to simulate the plume characters under different kinds of relative humidity. The three kinds of relative humidity were 70%, 80% and 90% and it was analyzed that the plume character under these three kinds of relative humidity. Results showed that the plume length, plume height and plume radius will present different change trend when relative humidity changed. Additionally, the plume dispersion character in different seasons presented obviously variations and the different wind direction also play important role in prediction of cooling tower plume dispersion.

The Effect of Wind Speed on Cooling Tower Plume Dispersion

2013 ◽  
Vol 732-733 ◽  
pp. 144-147
Author(s):  
Rui Ping Guo ◽  
Chun Lin Yang ◽  
Chun Ming Zhang
Keyword(s):  
Wind Speed ◽  
Impact Factor ◽  
Cooling Tower ◽  
Normal Operation ◽  
Plume Dispersion ◽  
Plume Height ◽  
Wind Speeds ◽  
Important Impact ◽  
Change Trend ◽  
Dispersion Character

Wind speed was an important impact factor when simulating the cooling tower plume dispersion. The SACTI model was selected in this paper and this model was used to predict the plume dispersion character discharging from cooling tower under normal operation and three different kinds of wind speeds. The three kinds of wind speeds were 2 m/s, 4 m/s and 6 m/s and it was analyzed that the plume character under these three wind speeds. Results showed that the plume length, plume height and plume radius will present different change trend when wind speed changed.

scholarly journals The Environmental Effects of the April 2020 Wildfires and the Cs-137 Re-Suspension in the Chernobyl Exclusion Zone: A Multi-Hazard Threat

Atmosphere ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 467
Author(s):  
Rocío Baró ◽  
Christian Maurer ◽  
Jerome Brioude ◽  
Delia Arnold ◽  
Marcus Hirtl
Keyword(s):  
Air Quality ◽  
Nuclear Power ◽  
Transport Model ◽  
Atmospheric Transport ◽  
Point Of View ◽  
Plume Dispersion ◽  
Exclusion Zone ◽  
Fire Plume ◽  
Mean Values ◽  
The Impact

This paper demonstrates the environmental impacts of the wildfires occurring at the beginning of April 2020 in and around the highly contaminated Chernobyl Exclusion Zone (CEZ). Due to the critical fire location, concerns arose about secondary radioactive contamination potentially spreading over Europe. The impact of the fire was assessed through the evaluation of fire plume dispersion and re-suspension of the radionuclide Cs-137, whereas, to assess the smoke plume effect, a WRF-Chem simulation was performed and compared to Tropospheric Monitoring Instrument (TROPOMI) satellite columns. The results show agreement of the simulated black carbon and carbon monoxide plumes with the plumes as observed by TROPOMI, where pollutants were also transported to Belarus. From an air quality and health perspective, the wildfires caused extremely bad air quality over Kiev, where the WRF-Chem model simulated mean values of PM2.5 up to 300 µg/m3 (during the first fire outbreak) over CEZ. The re-suspension of Cs-137 was assessed by a Bayesian inverse modelling approach using FLEXPART as the atmospheric transport model and Ukraine observations, yielding a total release of 600 ± 200 GBq. The increase in both smoke and Cs-137 emissions was only well correlated on the 9 April, likely related to a shift of the focus area of the fires. From a radiological point of view even the highest Cs-137 values (average measured or modelled air concentrations and modelled deposition) at the measurement site closest to the Chernobyl Nuclear Power Plant, i.e., Kiev, posed no health risk.

scholarly journals Nitrogen Mass Balance and Pressure Impact Model Applied to an Urban Aquifer

Water ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 1171 ◽  
Author(s):  
Mitja Janža ◽  
Joerg Prestor ◽  
Simona Pestotnik ◽  
Brigita Jamnik
Keyword(s):  
Groundwater Quality ◽  
Urban Areas ◽  
Transport Model ◽  
Nitrate Concentration ◽  
Impact Model ◽  
Sewer System ◽  
Management Measures ◽  
Pressure Impact ◽  
The Impact ◽  
The City

The assurance of drinking water supply is one of the biggest emerging global challenges, especially in urban areas. In this respect, groundwater and its management in the urban environment are gaining importance. This paper presents the modeling of nitrogen load from the leaky sewer system and from agriculture and the impact of this pressure on the groundwater quality (nitrate concentration) in the urban aquifer located beneath the City of Ljubljana. The estimated total nitrogen load in the model area of 58 km2 is 334 ton/year, 38% arising from the leaky sewer system and 62% from agriculture. This load was used as input into the groundwater solute transport model to simulate the distribution of nitrate concentration in the aquifer. The modeled nitrate concentrations at the observation locations were found to be on average slightly lower (2.7 mg/L) than observed, and in general reflected the observed contamination pattern. The ability of the presented model to relate and quantify the impact of pressures from different contamination sources on groundwater quality can be beneficially used for the planning and optimization of groundwater management measures for the improvement of groundwater quality.

Predicting cooling tower plume dispersion

1997 ◽  
Vol 211 (4) ◽  
pp. 291-297 ◽  
Author(s):  
B E A Fisher
Keyword(s):  
Cooling Tower ◽  
Industrial Process ◽  
Local Environment ◽  
Meteorological Conditions ◽  
Performance Criteria ◽  
Plume Dispersion ◽  
Cooling Towers ◽  
Atmospheric Conditions ◽  
Operating Characteristics

An assessment of the effects of visible cooling tower plumes on the local environment can be a necessary part of any proposal for a new large industrial process. Predictions of the dispersion of plumes from cooling towers are based on methods developed for chimney emissions. However, the kinds of criteria used to judge the acceptability of cooling tower plumes are different from those used for stack plumes. The frequency of long elevated plumes and the frequency of ground fogging are the two main issues. It is shown that events associated with significant plume visibility are dependent both on the operating characteristics of the tower and on the occurrence of certain meteorological conditions. The dependence on atmospheric conditions is shown to be fairly complex and simple performance criteria based on the exit conditions from the tower are not sufficient for assessments.

The impact model of cumulative damage on the detection threshold of space optical communication

2010 ◽  
Author(s):  
Guolong Chang ◽  
Yanping Zhou ◽  
Jing Ma ◽  
Jianqiang Zhou ◽  
Bingnan Zhao ◽  
...  
Keyword(s):  
Optical Communication ◽  
Detection Threshold ◽  
Cumulative Damage ◽  
Impact Model ◽  
Space Optical Communication ◽  
The Impact

scholarly journals Slow Decay of Impact in Equity Markets

2015 ◽  
Vol 01 (02) ◽  
pp. 1550007 ◽  
Author(s):  
X. Brokmann ◽  
E. Sérié ◽  
J. Kockelkoren ◽  
J.-P. Bouchaud
Keyword(s):  
Power Law ◽  
Equity Markets ◽  
Impact Model ◽  
Market Impact ◽  
Temporal Dependence ◽  
Raw Data ◽  
Slow Decay ◽  
First Approximation ◽  
Information Contents ◽  
The Impact

Using a proprietary dataset of meta-orders and prediction signals, and assuming a quasi-linear impact model, we deconvolve market impact from past correlated trades and a predictable return component to elicit the temporal dependence of the market impact of a single daily meta-order, over a 10-day horizon in various equity markets. We find that the impact of single meta-orders is to a first approximation universal and slowly decays to zero (or to a small value), possibly as a power-law. We show that autocorrelated order-flows and trade information contents fully accounts for the apparent plateau observed in the raw data. We discuss the possible bias introduced by the quasi-linear assumption.

scholarly journals Modelling the impact of a new tobacco product: review of Philip Morris International’s Population Health Impact Model as applied to the IQOS heated tobacco product

2018 ◽  
Vol 27 (Suppl 1) ◽  
pp. s82-s86 ◽  
Author(s):  
Wendy B Max ◽  
Hai-Yen Sung ◽  
James Lightwood ◽  
Yingning Wang ◽  
Tingting Yao
Keyword(s):  
Population Health ◽  
New Product ◽  
Health Impact ◽  
Tobacco Product ◽  
Dynamic State ◽  
Model Parameters ◽  
Impact Model ◽  
Tobacco Products ◽  
Philip Morris ◽  
The Impact

ObjectivesWe review the Population Health Impact Model (PHIM) developed by Philip Morris International and used in its application to the US Food and Drug Administration (FDA) to market its heated tobacco product (HTP), IQOS, as a modified-risk tobacco product (MRTP). We assess the model against FDA guidelines for MRTP applications and consider more general criteria for evaluating reduced-risk tobacco products.MethodsIn assessing the PHIM against FDA guidelines, we consider two key components of the model: the assumptions implicit in the model (outcomes included, relative harm of the new product vs cigarettes, tobacco-related diseases considered, whether dual or polyuse of the new product is modelled, and what other tobacco products are included) and data used to estimate and validate model parameters (transition rates between non-smoking, cigarette-only smoking, dual use of cigarettes and MRTP, and MRTP-only use; and starting tobacco use prevalence).ResultsThe PHIM is a dynamic state transition model which models the impact of cigarette and MRTP use on mortality from four tobacco-attributable diseases. The PHIM excludes morbidity, underestimates mortality, excludes tobacco products other than cigarettes, does not include FDA-recommended impacts on non-users and underestimates the impact on other population groups.ConclusionThe PHIM underestimates the health impact of HTP products and cannot be used to justify an MRTP claim. An assessment of the impact of a potential MRTP on population health should include a comprehensive measure of health impacts, consideration of all groups impacted, and documented and justifiable assumptions regarding model parameters.

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