Description
CHAPTER ONE
INTRODUCTION
BACKGROUND OF THE STUDY
Particulate matter (PM) and gaseous compounds (SO2,NOx,VOC) emitted by diesel engines causes serious global environmental problems and health impact. Despite numerous evidences about the harmfulness of diesel particles, the PM emission by diesel engines used by ships, cars, agricultural machines, or power generators is still unregulated, and the efficient removal of PM from diesel exhausts is still the major technological challenge.
Ocean transportation has a relatively wide coverage with respect to railway transportation, and its cost is also superior to air transportation. It is one of the most important modes of transportation in international logistics. With the continuous development of the shipping industry, more than 95% of the world’s total trade volume is borne by the shipping industry, and its total energy consumption accounts for 3% of total energy. Marine diesel engine is the heart of ship work, and it is also the main place for energy consumption and pollutant generation. Based on this, determining the ways of energy saving and emission reduction of diesel engines and using corresponding technologies based on these routes is the main way to control the formation of pollutants.
The exhaust gas generated by the marine diesel engine is mainly composed of the combustion products of the fuel and the remaining air. The main component of the composition that can cause pollution to the atmospheric environment and cause harm to human health is carbon monoxide, nitrogen oxides, hydrocarbons, sulfur oxides and particles. Insufficient fuel combustion in marine diesel engines is the main cause of carbon monoxide production. The sudden decrease in temperature in marine diesel engines, the lack of oxygen and the accumulation of reactants can cause fuel combustion to be insufficient. Excessive temperature in the diesel engine, excessive oxygen content, and excessive residence time of nitrogen and oxygen are the main causes of nitrogen oxides. The mechanism of hydrocarbon generation is very complicated, but the root cause is due to incomplete combustion of hydrocarbons. The formation of particles is closely related to the running state.
There are different methods of reducing emission from marine diesel engine but in this work we are considering using turbocharger.
Turbochargers are used throughout the automotive/marine industry to enhance the output of an internal combustion engine without increasing the cylinder capacity. The application of such a mechanical device enables automotive manufacturers to adopt smaller displacement engines, commonly known as engine downsizing. Turbochargers were often used to increase the potential of an already powerful IC engine, e.g. those used in motorsport. The emphasis today is to provide a feasible engineering solution to manufacturing economics and “greener” road vehicles. It is because of these reasons that turbochargers are now becoming much more popular in marine industry applications.
1.2 STATEMENT OF THE PROBLEM
Air pollutants harm the environment and human health. Damages to lungs which linked to heart disease, lower birth weight in newborns and increased risk of premature death is caused by air pollutant such as NOx. NOx can also lead to acid rain, which damages crops, vegetation and infrastructure, and contributes to the pollution of coastal waters and poor air quality in the form of smog.
Exhaust gas emissions increasingly become a more stringent topic of public interest in the context of merchant shipping industry. Exhaust emissions from marine diesel engines comprise nitrogen, oxygen, carbon dioxide (CO2), carbon monoxide (CO), oxides of sulphur (SOx), nitrogen oxides (NOx), hydrocarbons, water vapor and smoke. Oxides of nitrogen and sulphur are of special concern as threats to vegetation, the environment and human health. Despite numerous evidences about the harmfulness of diesel particles, the particulate matter (PM) emission by diesel engines used by ships is still unregulated, and the efficient removal of PM from diesel exhausts is still the major technological challenge. In order to comply with the International Maritime Organization regulation, the NOx emission is reduced by using selected technology – turbocharge. This work was carried out to study how a turbo charger can be used in reducing emission in marine diesel engine.
1.3 AIM AND OBJECTIVES OF THE STUDY
The main aim of this work is to study how emission in marine diesel engine can be reduced using turbocharger.
The objectives of the study are:
- To create a growing awareness of environmental protection
- To study the application of emission reduction technologies, and provides some theoretical foundations for future marine undertakings.
- To study different mathematical formulas that relate to marine diesel engine emission reduction using turbocharger.
1.4 SIGNIFICANCE OF THE STUDY
This study will provide some technical solutions to reduce the emissions from diesel engines. The study will serve as a means of understanding marine engine emission, the causes and its reduction processes.
The study will also serve as means of studying the effect of marine diesel engine emission on human being and marine animal.
