Research On Characteristic Detection Of Typical Pollutants Emitted By Ships Nearshore

As ship transportation is the most economical international transportation mode for most goods.While the world and China’s shipping is developin prosperously,an important problem we have to solve is the pollution caused by ships.Compared with the high seas,the coastal waters are close to the populated areas and the density of ships in ports,waterways and anchorages is higher.Serious environmental pollution from industrialization and the additional increase of ship pollution will raise greater environmental pressure.A comprehensive inspection of ships’near-shore emission is indispensable in marine traffic information detection and monitoring.It can make ship emissions more intuitive,and provide data and technical support for the realization of water transportation pollution prevention and control technologies such as ship oil control,speed control and emission reduction.At the same time,obtaining accurate emission data is an important prerequisite for the effective implementation of emission control measures.Based on the objective requirement of ship pollution supervision and reduction control in current transportation from IMO and China,the thesis takes the typical pollutants emitted by ships that mainly affect air quality as the research object,and carries out the detection experiments of ship emission gaseous pollution and particles pollution respectively.The results of this thesis mainly include:（1）In terms of ship gaseous emission characteristics,a typical Chinese near-shore ship is selected.A set of platforms suitable for the detection of pollutant emissions of sea-going ships are built at the main engine flue opening.Ship navigation data and pollution emission data of 6complete operating conditions are collected,including berthing,in-port maneuver,channel speed-up maneuver,cruising,deceleration before anchoring and anchoring.The emission concentration characteristics of O₂,NO_X,SO₂,CO₂,and CO in ship exhaust under different operating conditions are analyzed.Moreover,the corresponding relationship between exhaust emission concentration,ship speed,engine power and oil are shown.The fitting model for the SO₂ emission concentration of the ship is established by the multiple linear regression least square method.The z-schore standardized data processing is used to verify that the main factors affecting the SO₂ concentration in the main engine flue are the main engine load and fuel sulfur content.Because the emission detection of ships is expensive and difficult,and the actual emission data is relatively scarce.This study obtains the emission factors of emission pollutants based on the engine power under different operating conditions,and the research results supplement the lack of emission data for the local emission detection of this type of ships,especially that under near-shore mooring conditions.Compare with the emission factors obtained by Chinese coastal ships and the main international common factors used in the domestic port emission inventory,it is found that the international common factors of some pollutants are not suitable for localized use,and need to be further research.In view of the current problems in emission regulation,based on the correlation between the concentration ratio of S/C（SO₂/C O₂）and the concentration ratio of S/N（SO₂/NO_X）,a new model was established between the ratio and the fuel sulfur content（FSC）of ships.The new model can accurately estimate the FSC value under the cruising condition of the ship.（2）In terms of ship gaseous emission estimation,a new coordination method is proposed to reduce the estimation error,which can solve the problem that the near-shore berthing and anchoring conditions are often ignored in the current ship emissions calculated by the dynamic method.This method fully considers the different emission characteristics of ships in berthing and low-speed navigation,as well as in maneuvering conditions and constant speed cruise conditions with high ship speed.Based on the currently available ship data.The estimation formula of the actual engine power is improved.The experiment verification shows that the proposed method can obtain more accurate emissions of pollutants under different operating conditions while reducing uncertainty.Aiming at the important issues of rapid implementation of nearshore ship emission reduction and intelligent ship speed reduction and emission reduction control,a ship speed reduction method is proposed by using the exponential and logarithmic relationship between the test ship’s main engine power,ship speed and fuel consumption.The method provides a new way to reduce the emission of near-shore ships.（3）In terms of the characteristic detection of the pollution of dry bulk particles,the simulation experiment under real sea ice conditions of north China Sea,which is rarely studied at home and abroad,has been carried out.Through the on-site measurement of the reflectivity of sea ice-pulverized coal particles,the results are obtained.Based on the spectral reflectance data of sea ice with different pollution levels,it is found that the characteristics of the mixed pixels of sea ice and coal particles can be described by linear mixed pixels.By selecting the average reflectance in the 1600nm～1630nm wide band,the geometric cross-sectional area ratio of the pulverized coal particles in the sea ice-pulverized coal pixel is more accurately estimated under the influence of the sea ice background reflectance.The research results of this thesis provide important basic data and feasible methods for remote detection of pulverized coal particle pollution on large-scale sea ice surface.