Thesis

Investigation into the mechanism of Wet Electrostatic Scrubber (WES) for fine particles capture

Creator
Rights statement
Awarding institution
  • University of Strathclyde
Date of award
  • 2025
Thesis identifier
  • T17191
Person Identifier (Local)
  • 201961895
Qualification Level
Qualification Name
Department, School or Faculty
Abstract
  • In the context of increasing global maritime trade, emissions from marine diesel engines, primarily using Heavy Fuel Oil (HFO) and Marine Gas Oil (MGO), pose significant environmental and health risks. These emissions, especially particulate matter (PM), contribute to climate change, acid rain, and ecosystem damage. Among the methods for reducing PM from marine diesel engines, electrohydrodynamic techniques show promise. This thesis proposes a theoretical model to describe particle movement in a wet electrostatic scrubber (WES) for capturing emissions from marine diesel engines. In the WES, exhaust gases pass through a high-voltage electric field, ionizing particles which then interact with oppositely charged water droplets. These droplets capture the particles through electrostatic attraction, resulting in cleaner exhaust gas. A detailed scientific explanation of this particle-droplet interaction is uncommon. The model presented considers various factors such as electric field strength, gas flow conditions, particle characteristics, and droplet size. By optimally selecting conditions for electric and flow fields, particle removal efficiency can be enhanced. The framework aligns gas flow, temperature, and electrostatic fields to optimize particle capture. The thesis investigated the mechanism of particle capturing process in a WES. The thesis proposes that through developing a theoretical description and analysing the motion characteristics. The core of this thesis is threefold: (1) A mathematical model incorporating electrostatic force and flow field distribution around the droplet is developed. By solving equations for particle movement and stream function distribution, the model describes particle-droplet interactions under an electrostatic field. Analysis shows that electric fields increase particle velocity and capture efficiency, with larger particles being more affected. Smaller droplet sizes enhance particle collection. (2) A co-simulation method using ANSYS Fluent and MATLAB simulates the particle motion process. Simulation results are consistent with mathematical calculation data, showing an average error of 1.5%. (3) An experimental platform was established to observe and record particle motion using a high-speed camera. Analysis confirms that charged droplets effectively capture charged particles, with increased electric field strength boosting capture efficiency. In conclusion, this thesis develops a theoretical electrohydrodynamic method to explain particle movement in WES, providing a scientific framework for reducing PM emissions from marine diesel engines. A co-simulation method is obtained to simulate this motion process and verify the theoretical results. Also, an experiment is conducted to verify the results of the theoretical model.
Advisor / supervisor
  • Zhou, Peilin
  • Mei, Ning
Resource Type
DOI

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