Date of Award

2020

Document Type

Campus Access Master's Thesis

Degree Name

Master of Science in Mechanical Engineering (MS)

Administrative Home Department

Department of Mechanical Engineering-Engineering Mechanics

Advisor 1

Sajjad Bigham

Committee Member 1

Hassan Masoud

Committee Member 2

Fernando Ponta

Abstract

With the rapid rise in urbanization, the standard of life has dramatically increased across the world over the past few decades. This has significantly augmented the thermal comfort requirements of residential and commercial buildings, thereby increasing their energy demands. State-of-the-art-air conditioning (AC) technologies employ energy intensive and environmentally detrimental components and processes resulting in high energy consumptions. Particularly, sensible (i.e., temperature) and latent (i.e., humidity) cooling loads are coupled in standard AC systems. This requires to substantially overcool a humid air stream to below dew point to dehumidify the supply air. The added overcooling and subsequent heating to return the air to the comfort zone consume significant amount of energy, and thus reduce the AC energy efficiency. Separate sensible and latent cooling (SSLC) systems, on the other hand, decouple sensible and latent cooling loads, and thus improve AC performance as no overcooling is needed. This study aims to examine performance of a lung-inspired 3D-printed desiccant-coated heat exchanger (DCHX) for the dehumidification process. The proposed design is inspired from the bronchi arrangement of a human lung demonstrating an improved flow distribution for efficient heat and mass transfer rates. Particularly, the lung-inspired design employs two intertwined continuous networks for the incoming air and the cooling water, thereby ensuring a volumetric distribution of one fluid network within and through the other network. The dehumidification process is realized by hygroscopic properties of a solid desiccant material. These features of the proposed 3D-printed DCHX significantly improve the dehumidification rate. The 3D-printed DCHX could separately handle the latent cooling load of future buildings. Various parameters affecting the system performance including airflow rate, outdoor air relative humidity (RH), adsorption rate, regeneration temperature and intercooling effect are investigated. Results indicated that the lung-inspired DCHX demonstrate highly promising results for the dehumidification process of highly humid air streams. In fact, experimental results confirmed that the proposed lung-inspired 3d-printed DCHX offers a volumetric adsorption rate of around 14.6 g/m3-s, which significantly outperforms existing desiccant-based dehumidification systems.

Available for download on Monday, December 06, 2021

Share

COinS