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This work involves an experimental investigation of a novel air gap membrane distillation (AGMD) unit with an installed circulating fan within the condensation chamber. The installed fan breaks the resistance to mass and heat transfer in the gap chamber by inducing fluid mixing and a turbulent dissipation rate, which enhances the overall mass and heat transfer characteristics of the system and consequently the overall performance of the system. The system performance, such as vapor flux, specific thermal energy consumption (STEC), and desalinated water cost, of the new AGMD is evaluated and compared to the traditional AGMD system. The influence of fan design variables, including fan revolution, fan thickness, and fan diameter, on system performance is investigated. Furthermore, the effect of feed water temperature on the system's performance is assessed and presented. Results indicate that fan speed significantly improves the performance of the new AGMD system compared to conventional AGMD designs. Fan thickness recorded a marginal effect, and fan diameter registered some influence, while fan revolution exhibits the strongest impact on the system's performance. The new system can attain a maximum flux and minimum STEC of 34.16 kg/m2·h and 710.72 kWh/m3, respectively, as against the conventional units, which registered a peak vapor flux and lowest STEC of 17.69 kg/m2·h and 1,141.25 kWh/m3, respectively. [ABSTRACT FROM AUTHOR]

The amount of resources devoted to saltwater desalination is substantial and will only rise as the scarcity of water escalates globally. Desalination techniques for seawater, particularly thermal desalination techniques, require a lot of energy and utilize conventional energy sources. The goal of this article is to examine the integration of thermal desalination techniques with carbon capture and sequestration (CCS) power generation. This study utilizes an oxy-combustion-based zero-emission power plant and investigates the performance of a humidification-dehumidification (HDH) cycle integrated with the main cycle. The system constitutes two main cycles, namely (i) oxy-combustion power generation cycle (OPGC) and (ii) humidification-dehumidification (HDH) cycle. The performance of several bottoming cycles coupled with a closed-air-open-water water-heated (CAOW-WH) HDH system is studied to evaluate the thermodynamic feasibility of the system. The effect of top and bottom temperatures of the HDH system and mass flow rates are optimized for gain output ratio (GOR) and recovery rate (RR). A sensitivity analysis of the integrated system was also conducted, and the effect of oxy-combustion operating parameters on the net cycle efficiency was examined. This analysis offers crucial design considerations for such integrated systems to generate power with zero emissions and produces sweet water without additional energy costs. [ABSTRACT FROM AUTHOR]

Concentric tube heat exchangers are widely used as lube oil coolers in large internal combustion engines. They are particularly preferred because of simple manufacturing, lower area, and better heat transfer characteristics. With the growing use of unconventional fuel-based lubricants, their design is continuously improved to achieve the required heat transfer characteristics. One of the emerging alternative oil is Tire Pyrolysis Oil (TPO) to minimize tire waste and achieve the waste-to-energy objective. The TPO is employed not only as diesel blended fuel but also as a lube oil because of its satisfactory tribological properties. The present work provides a detailed design and analysis of a concentric-tube micro-fin-based lube oil cooler for TPO applications. The design encompasses the thermal, hydraulic, and economic characteristics of the heat exchanger subjected to TPO, Ethylene Glycol (EG), and Crude Oil (CO). To achieve this a robust numerical model is developed and implemented using engineering equation solver software. The model is validated with experimental data first. Then a detailed parametric analysis is done to investigate the heat exchanger performance. It was observed that TPO offered a better heat transfer coefficient along with lesser power input and cost compared to EG and CO. For instance, in the case of a mass flow rate 0.1 kg/s, the heat transfer per unit pressure drop is highest for TPO with 5.86 m/sK followed by CO with 5.12 m/sK and EG with 0.3876 m/sK. Similarly, the annual operational cost is calculated as 27.7 k$, 31.4 k$, and ∼ 80.8 k$ for the TPO, CO, EG which shows the superiority of TPO as lube oil for engine applications. Based on thermal, hydraulic design and economic analysis, it is concluded that tire pyrolysis oil (TPO) is used in the concentric tube micro fin heat exchanger for applications of oil cooling. [ABSTRACT FROM AUTHOR]