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The airflow structure of enclosures directly affects the spread of COVID-19 and is also closely related to indoor air quality, the thermal comfort of personnel, and buildings' energy consumption. A large number of studies on airflow field under mixing and displacement ventilation with a single air inlet in rectangular rooms have been conducted; however, to the best of the authors' knowledge, only a limited number of studies have dealt with airflow structures in a multi-slot ventilation enclosure with opposed jets. Therefore, this paper uses PIV to study the velocity, turbulence information, and entropy of an unstable airflow field in a multi-slot ventilation enclosure with opposed jets under isothermal and non-isothermal conditions. This paper also presents, due to the collision of the jets to form two large-scale eddies, the airflow field structure being unstable. In the region without air supply inlets and exhaust outlets, a large-scale vortex is formed in the airflow field, resulting in the high information entropy of the flow field. The thermal plume suppresses the large-scale flow field structure and increases the small-scale flow field structure. [ABSTRACT FROM AUTHOR]

Featured Application: The elbow-type thermal storage tank is an innovative solution for thermal energy storage, with a uniquely designed bent pipe inlet structure that significantly increases hot water output and optimizes thermal stratification. This tank has demonstrated exceptional performance in reducing hot/cold water mixing and improving hot water availability. With its simple manufacturing process and easy installation, it not only meets users' demands for an efficient hot water energy-saving application but is also in line with modern environmental and energy-saving concepts. The elbow-type storage tank has a wide range of applications in areas such as energy-efficient air conditioning and residential buildings, offering a new approach to energy use. Thermal storage tanks are the most widely used devices for thermodynamic storage. Their stratification performance is a key factor in determining their effectiveness. In this study, a structure was proposed to improve the thermal stratification of an elbow-type thermal storage tank. An experimental study was conducted on its exothermic properties for applications in hot water storage tanks. An experimental analysis was performed to investigate the exothermic properties of the proposed structure, and the results were compared with those obtained from simulations using CFD (ANSYS 19.1) software. To investigate the effect of thermal stratification on the water inlet structure, the Richardson number, hot water output rate, and MIX number of the elbow inlet structure were compared with those of the water distributor inlet structure. The results show that the MIX numbers corresponding to the inlet structures of the two types of tanks, the elbow and water distributor types, are not very different. These values were almost identical to the Richardson numbers. Under the same working conditions, the hot water output rate was 84.90% for the elbow inlet structure and 76.39% for the water distributor inlet structure. In conclusion, elbow-type water inlet structures are easy to install, and the manufacturing process is simplified. [ABSTRACT FROM AUTHOR]

Human behaviors including consumption of drugs and use of personal care products, climate change, increased international travel, and the advent of water reclamation for direct potable use have led to the introduction of significant amounts of emerging organic contaminants into the aqueous environment. In addition, the lower detection limits associated with improved scientific methods of chemical analysis have resulted in a recent increase in documented incidences of these contaminants which previously were not routinely monitored in water. Such contaminants may cause known or suspected adverse ecological and/or human health effects at very low concentrations. Conventional drinking water treatment processes may not effectively remove these organic contaminants. Advanced oxidation process (AOP) is a promising treatment process for the removal of most of these emerging organic contaminants, and has been accepted worldwide as a suitable treatment process. In this study, different groups of emerging contaminants were studied for decomposition efficiency using pilot-scale UV/H2O2 oxidation setup, including EDCs, PPCPs, taste and odor (T&O), and perfluorinated compounds. Results found that MP UV/H2O2 AOP was efficient in removing all the selected contaminants except perfluorinated compounds. Study of the kinetics of the process showed that both light absorption and quantum yield of each compound affected the decomposition performance. Analysis of water quality parameters of the treated water indicated that the outcome of both UV photolysis and UV/H2O2 processes can be affected by changes in the feed water quality. [ABSTRACT FROM AUTHOR]