scholarly journals Laser remote monitoring of hazardous substances emissions by ship power plants

2021 ◽  
pp. 75-81
Author(s):  
В.А. Туркин ◽  
Г.В. Игнатенко ◽  
И.А. Сарычев ◽  
Р.И. Джиоев
Keyword(s):  
Laser Radiation ◽  
Electromagnetic Waves ◽  
Power Plants ◽  
Aerosol Particles ◽  
Laser System ◽  
Mie Scattering ◽  
Hazardous Substances ◽  
Laser Method ◽  
Soot Particles ◽  
Surface Diameter

При сгорании топлива в судовом двигателе образуются частицы сажи, которые сорбируют в себе токсичные компоненты отработавших газов. Размеры этих частиц варьируются от 0,1 до 100 мкм. В области возможных диапазонов варьирования размеров частиц сажи актуальным является видимая и ближняя ИК-область электромагнитных волн. Решая обратную задачу ослабления и рассеяния света частицами можно получить информацию о концентрации и функции распределения частиц по размерам. Выполнен анализ возможности одновременной оценки концентрации и дисперсности лазерным методом дифференциального ослабления и описан вариант его технической реализации. Разработана четырех волновая лазерная система, которая позволяет измерять сигналы ослабления лазерного излучения методом дифференциального ослабления на трех длинах волн и сигнал рассеяния Ми на частицах аэрозоля излучения четвертого лазера. По измеренным сигналам ослабления рассчитан средний объемно-поверхностный диаметр аэрозольных частиц. Измерены сигналы ослабления лазерного излучения на трех длинах волн на разработанной лазерной установке в составе экспериментального стенда, что позволяет рассчитать значения массовой концентрации и среднего объемно-поверхностного диаметра аэрозольных частиц. Показано, что в зависимости от диапазона размеров частиц сажи выбираются соответствующие длины волн лазерного зондирования. Применение метода дифференциального ослабления лазерного излучения частицами сажи в выбросах судовых энергетических установок на нескольких длинах волн позволяет оценивать одновременно их концентрацию и характеристики дисперсности. When fuel is burned in a marine engine, soot particles are formed that absorb the toxic components of the exhaust gases. The sizes of these particles range from 0.1 to 100 microns. In the range of possible ranges of variation in the size of soot particles, the visible and near-IR regions of electromagnetic waves are relevant. By solving the inverse problem of attenuation and scattering of light by particles, one can obtain information about the concentration and distribution function of particles by size. The analysis of the possibility of simultaneous assessment of the concentration and dispersion by the laser method of differential attenuation is performed and a variant of its technical implementation is described. A four-wave laser system has been developed, which makes it possible to measure the attenuation signals of laser radiation by the differential attenuation method at three wavelengths and the Mie scattering signal on aerosol particles of the radiation of the fourth laser. The measured attenuation signals were used to calculate the average volumetric surface diameter of aerosol particles. The signals of the attenuation of laser radiation at three wavelengths were measured on a developed laser setup as part of an experimental stand, which makes it possible to calculate the values of the mass concentration and the average volume-surface diameter of aerosol particles. It is shown that, depending on the range of size of soot particles, the corresponding laser sounding wavelengths are chosen. The application of the method of differential attenuation of laser radiation by soot particles in the emissions of ship power plants at several wavelengths allows one to evaluate simultaneously their concentration and dispersion characteristics.

scholarly journals Internally mixed soot, sulfates, and organic matter in aerosol particles from Mexico City

2008 ◽  
Vol 8 (3) ◽  
pp. 9179-9207 ◽  
Author(s):  
K. Adachi ◽  
P. R. Buseck
Keyword(s):  
Organic Matter ◽  
Mexico City ◽  
Power Plants ◽  
Aerosol Particles ◽  
Radiation Budget ◽  
Cloud Formation ◽  
Multiple Sources ◽  
Soot Particles ◽  
Hygroscopic Properties ◽  
Individual Particles

Abstract. Soot particles are major aerosol constituents that result from emissions of burning of fossil fuel and biomass. Because they both absorb sunlight and contribute to cloud formation, they are an influence on climate on local, regional, and global scales. It is therefore important to evaluate their optical and hygroscopic properties and those effects on the radiation budget. Those properties commonly change through reaction with other particles or gases, resulting in complex internal mixtures. Using transmission electron microscopy, we measured ~8000 particles (25 samples) with aerodynamic diameters from 0.05 to 0.3 μm that were collected in March 2006 from aircraft over Mexico City (MC) and adjacent areas. More than 50% of the particles consist of internally mixed soot, organic matter, and sulfate. Imaging combined with chemical analysis of individual particles show that many are coated, consist of aggregates, or both. Coatings on soot particles can amplify their light absorption, and coagulation with sulfates changes their hygroscopic properties, resulting in shorter lifetime. Our results suggest that a mixture of materials from multiple sources such as vehicles, power plants, and biomass burning occurs in individual particles, thereby increasing their complexity. Through changes in their optical and hygroscopic properties, internally mixed soot particles have a greater effect on the regional climate than uncoated soot particles. Moreover, soot occurs in more than 60% of all particles in the MC plumes, suggesting its important role in the formation of secondary aerosol particles.

Thermal Stress in Volcanic-Ash-Deposited Thermal Barrier Coatings Monitored by Long-Range Laser System

2016 ◽  
Vol 713 ◽  
pp. 293-296
Author(s):  
Masayuki Arai ◽  
Daichi Yamaura
Keyword(s):  
Thermal Stress ◽  
Power Plants ◽  
Volcanic Ash ◽  
Thermal Power ◽  
Laser System ◽  
Tokyo Bay ◽  
Thermal Barrier ◽  
Ash Deposition ◽  
Barrier Coating ◽  
Laser Monitoring

All thermal power plants including gas turbine (GT) of Tokyo electric company are located along Tokyo bay. If Mt. Fuji is exploded, volcanic ash is fallen down in Kanto area. If volcanic ash is inhaled into GTs, the ash would be firstly impacted and deposited onto thermal barrier coating (TBC) of the blades. Such deposition of the volcanic ash causes the delamination of the ceramic coating. In this study, TBC delamination mechanisms due to the volcanic ash deposition is discussed based upon thermal stress evaluated by a laser monitoring measurement system.

Laser Absorption Techniques for the Measurementof Atmospheric Water Vapor Concentration

1977 ◽  
Vol 16 (10) ◽  
pp. 1072-1076 ◽  
Author(s):  
E. Brannen ◽  
Z. Kucerovsky
Keyword(s):  
Water Vapor ◽  
Laser Radiation ◽  
Response Time ◽  
Water Vapor Pressure ◽  
Ground Level ◽  
Fast Response ◽  
Vapor Concentration ◽  
Water Vapor Concentration ◽  
Laser Method ◽  
Laser Experiments

Abstract A sensitive laser method with fast response time has been developed which is suitable for measuringatmospheric water vapor concentration. The method utilizes the absorption of 33.02 and 27.972 pm radiationfrom a water vapor laser. Experiments were carried out in a 2 m controlled atmosphere absorption cell atconditions corresponding to ground-level to high-altitude atmospheric pressures. Typically, an absorptionof 1% was produced in a 1 m path length by a water vapor pressure of 1.1 Pa at ground level and 2.2 Paat 5 km using 33.02 pm laser radiation. With 27,972 pm laser radiation the absorption is about a factor 50less and can be used when higher concentrations of water vapor are encountered. The response time of thedetecting apparatus can be less than a second and still achieve these sensitivities. Possibilities of building anairborne instrument for measuring water vapor concentration are discussed.

Heating of three-layer solid aerosol particles by laser radiation

2002 ◽  
Vol 41 (18) ◽  
pp. 3700 ◽  
Author(s):  
Liudmila G. Astafyeva ◽  
Nikolai V. Voshchinnikov ◽  
Lawrence B. F. M. Waters
Keyword(s):  
Laser Radiation ◽  
Aerosol Particles ◽  
Solid Aerosol

Optical Modeling of Reflectivity Loss Caused by Dust Deposition on CSP Mirrors and Restoration of Energy Yield by Electrodynamic Dust Removal

2014 ◽  
Author(s):  
Jeremy Stark ◽  
Julius Yellowhair ◽  
John N. Hudelson ◽  
Mark Horenstein ◽  
Malay Mazumder
Keyword(s):  
Power Plants ◽  
Specular Reflection ◽  
Mie Scattering ◽  
Dust Removal ◽  
Dust Particles ◽  
Energy Yield ◽  
Dust Deposition ◽  
Optical Modeling ◽  
Specular Reflectivity ◽  
Semi Arid

For large scale CSP power plants, vast areas of land are needed in deserts and semi-arid climates where uninterrupted solar irradiance is most abundant. These power facilities use large arrays of mirrors to reflect and concentrate sunlight onto collectors, however, dust deposition on the optical surfaces causes obscuration of sunlight, resulting in large energy-yield losses in solar plants. This problem is compounded by the lack of natural clean water resources for conventional cleaning of solar mirrors, often with reflective surface areas of large installations exceeding a million square meters. To investigate the application of transparent electrodynamic screens (EDS) for efficient and cost effective dust removal from solar mirrors, both optical modeling and experimental verifications were performed. Prototype EDS-integrated mirrors were constructed by depositing a set of parallel transparent electrodes into the sun-facing surface of solar mirrors and coating electrodes with thin transparent dielectric film. Activation of the electrodes with a three-phase voltage creates an electrodynamic field that charges and repels dust electrostatically by Coulomb force and sweeps away particles by a traveling electrodynamic wave. We report here brief discussions on (1) rate of deposition and the properties of dust with respect to their size distribution and chemical composition in semi-arid areas of the southwest US and Mojave Desert and their adhesion to solar mirrors, (2) optical models of: (a) specular reflection losses caused by scattering and absorption by dust particles deposited on the surface based on Mie scattering theory, and (b) reflection loss by the integration of EDS on the mirror surface, computed by FRED ray-tracing model. The objective is to maintain specular reflectivity of 90% or higher by frequent removal of dust by EDS. Our studies show that the incorporation of transparent EDS would cause an initial loss of 3% but would be able to maintain specular reflectivity more than 90% to meet the industrial requirement for CSP plants. Specular reflection measurements taken inside a climate controlled environmental chamber show that EDS integration can restore specular reflectivity and would be able to prevent major degradation of the optical surface caused by the deposition of dust.

Evolution of atmospheric aerosol particles during a pollution accumulation process: a case study

2015 ◽  
Vol 12 (1) ◽  
pp. 51-60 ◽  
Author(s):  
Hongya Niu ◽  
Wei Hu ◽  
Wei Pian ◽  
Jingsen Fan ◽  
Jinxi Wang
Keyword(s):  
Fine Particles ◽  
Aerosol Particles ◽  
Urban Site ◽  
Accumulation Process ◽  
Soot Particles ◽  
Secondary Particles ◽  
The Core ◽  
Pollution Accumulation ◽  
Number Frequency ◽  
Haze Formation

The characteristics of fine aerosol particles were investigated at an urban site in Beijing during an atmospheric pollution accumulation process. The organics, sulfate and BC were the dominant components in fine particles in the clear air, and the concentrations of organics, sulfate, nitrate and ammonium increased during the haze formation. The mass concentrations of primary species (chloride and BC) in the clear air were similar to those in the haze. The morphology, mixing state and aging status of fine particles in the clear air were different from those in the haze. Accumulation secondary particles were detected with high frequency and accumulation secondary particles with coating were rare in all the samples. The frequency of soot particles with coating in the clear air was lower than that in the haze. The number ratio of accumulation secondary particles to soot containing particles changed from 3:1 in clear air to 2:3 in the haze. These results indicated that the number frequency of accumulation secondary particles decreased while that of the soot containing particles increased with the air pollutants accumulating. The core-shell ratio of coated soot particles ranged between 0.1–0.6 was 62% in the clear air, and 82% in the haze. The mode sizes for the core and the shell of soot particles were 0.35 μm and 0.55 μm in the clear air, and 0.35 μm and 1.0 μm in the haze, respectively. The mean diameters of the core and the shell were 0.3 μm and was 0.6 μm in the clear air, and 0.4 μm and 1.0 μm in the haze, respectively. These results indicated that with the air pollution accumulating, the frequency of accumulation secondary particles decreased while the soot containing particles increased. The aging process of soot particles was stronger in the haze, and resulted in greater hygroscopicity for soot particles in the haze.

scholarly journals A Theory for the Separation of Liquid Mixtures by Laser Radiation

2003 ◽  
Vol 12 (3) ◽  
pp. 179-187
Author(s):  
H. G. Hassanov
Keyword(s):  
Laser Radiation ◽  
Laminar Flow ◽  
Radiation Intensity ◽  
Electromagnetic Waves ◽  
Liquid Mixtures ◽  
Extreme Value ◽  
Mixture Separation

A theory for the separation of liquid mixtures under the action of electromagnetic waves is developed. The theory considers physical specifications that take place during the separation. It is shown that at certain extreme value of the radiation intensity the maximum of mixture separation could be observed. This extreme value depends on the parameters of falling waves and medium studied. The effect of the liquid convection on the mixture separation is investigated. It is established that convection reduces the separation. Thus, laminar flow is much more preferable for the mixture separation than turbulent one.

Influence of Mie-scattering on high-speed micro-perforation considering brilliant laser radiation

2010 ◽  
Vol 22 (2) ◽  
pp. 48-55 ◽  
Author(s):  
M. Baumeister ◽  
T. Scholz ◽  
K. Dickmann ◽  
F. Vollersten
Keyword(s):  
Laser Radiation ◽  
High Speed ◽  
Mie Scattering
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