Numerical Analysis of Pressure Drop and Photoresist Particle Defect Accretion in HVAC Pipe System with Dampers
Authors: Park Changkyu , Kim Taesung 
Published: August 2024

The operational efficiency of HVAC (Heating, Ventilation, and Air Conditioning) systems is significantly impacted by the accumulation of particles leading to duct blockages. This research investigates the implementation of Lateral Dampers and Butterfly Dampers for airflow control, delving into the intricate mechanisms governing pressure loss within ducts due to particle deposition.
Efficient HVAC operation is paramount for energy conservation and indoor air quality. The hindrance caused by particle deposition-induced blockages in ducts impedes system efficiency. This study innovates airflow control mechanisms critical for optimizing energy consumption and ensuring sustainable HVAC performance.
Highlighting the novelty of this study, while prior research has explored fluid dynamics and particle deposition within ducts, the nuanced effects of damper configurations on particle deposition and pressure loss remain largely unexplored. This research addresses this gap by investigating the interplay between damper states, particle deposition, and pressure losses within HVAC duct systems.
The primary objective is to unravel the relationship between damper configurations and particle accretion within HVAC ducts. Utilizing Inventor 3D modeling and Computational Fluid Dynamics (CFD) simulations employing DPM (Discrete Phase Model) and Accretion Model, the study provides insights into how damper states influence particle deposition and subsequent pressure losses. The use of the Eulerian Wall Film (EWF) model enhances the accuracy of predicting the accretion on duct and damper surfaces.
Furthermore, this study extends its scope to investigate the particle information resulting from the photoresist bake process, including the generation of outgas and the principal component, benzo-pyrene. Specifically, the study examines the industrial duct's particle accretion and film formation arising from the interaction of these particles during outgas transport.
Findings reveal that, for Damper 1 to 3, variations in opening ratios have negligible effects on pressure within 5 Pa, suggesting minimal influence on system performance. Notably, Butterfly Dampers demonstrate a unique behavior where any one damper reaching full closure immediately results in a pressure drop to zero. Moreover, Butterfly Damper 1 and 2 significantly impact pressure, showcasing that at a 45-degree opening, the particle deposition rate is approximately 0.5 times the rate of pressure change.
The key takeaway is the development of a sophisticated algorithm for damper control, maintaining consistent pressure within ducts while optimizing airflow distribution. This algorithm has the potential to transform HVAC systems, ensuring minimal pressure loss, substantial energy savings, and heightened environmental sustainability.
In summary, this paper represents a comprehensive exploration of the intricate relationships between particle deposition, pressure loss, and damper control within HVAC duct systems. By shedding light on the complex mechanisms governing these phenomena, the study contributes to the development of advanced strategies for optimizing energy efficiency in HVAC operations.

Keywords: Photoresist, Particle Accretion, Film Formation, Eulerian Wall Film, Particle Deposition, CFD simulation, HVAC, Damper Control, Pressure Loss, Energy Efficiency.

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