## 2 Introduction of Latest Technologies and Research  
Studies are being conducted to minimize the impact of coal power generation systems on the environment. Many laser flow visualization methods have been presented to validate computational fluid dynamics (CFD). Therefore, this section introduces the latest technologies related to research on improving ventilation systems using CFD and experiments involving laser visualization techniques.  
[PERSON] et al. [13] developed a field-validated model that analyzes the dust dispersion effects of open stockpiles using CFD. Additionally, the closed warehouse structure was comprehensively analyzed and validated for warehouse construction using CFD.  
Particle image velocimetry (PIV) values of turbulent flow under unrestrained conditions were determined by [PERSON] [14]. A particle measurement study of turbulent open channel flow was used to examine correlation coefficient characteristics, indicating that the turbulence model function was irrelevant under continuous unrestrained conditions.  
An advanced method for a miniaturized PIV system was proposed by [PERSON] et al. [15]. He explained the characteristics and performance of this system while evaluating the PIV system and presenting its limitations.  
[PERSON] et al. [16] designed a mill-reactor using CFD and an artificial neural network and validated the CFD results using the PIV technique. As a result, a safe nuclear reactor design method was proposed. Additionally, he presented an optimal structure that satisfies heat transfer and mixing requirements.  
[PERSON], [PERSON] et al. [17] studied the effect of air pollution on the airflow rate in a clean room. Velocity and particle trajectories were investigated using Ansys Fluent and subsequently validated using the PIV method. As a result, the air changes per hour and airflow velocity accuracy inside the clean room explain the parameters behind the flow characteristics.  
[PERSON] et al. [18] studied a two-dimensional flow field measurement based on optical flow. The study proposed a new PIV technique that creates a two-dimensional velocity chamber for fluids containing sediment. Compared to existing algorithms, it offers superior smoothness and broad consistency.  
A hybrid method that overcomes the limitations of optical flow methods was designed by [PERSON], [PERSON] et al. [19]. This method compensates for changes in illuminance and obtains a refined high-resolution velocity field. A quantitative comparison was made between PIV measurements of circular air jets.  
In this literature, many studies have analyzed the flow characteristics using CFD and validated the results using PIV. Therefore, this study examines the internal flow characteristics of thermal power plant CSS using CFD. The simulation results are validated using PIV. The advantages of the flow visualization method proposed in this study are as follows. Extract specified color data and check flow information. Existing PIV and flow visualization experiments are expensive. However, the experiment proposed in this study has an advantage in terms of cost. In addition, it has advantages in analyzing the internal flow fields of large structures and buildings. Flow field analysis results are output relatively quickly.  
This thesis is divided into five sections: Section 2 introduces previous research and explains the composition of the thesis; Section 3 describes the methodological approach of numerical calculations and PIV experiments; Section 4 presents and analyzes the findings obtained in the study; and Section 5 presents the conclusions.