Experimental Investigation of Al2O3 - Water Ethylene Glycol Mixture Nanofluid Thermal Behaviour in a Single Cooling Plate for PEM Fuel Cell Application

AbstractThermal enhancement through application of nanofluid coolant in a single cooling plate of Proton Exchange Membrane (PEM) fuel cell was experimentally investigated in this paper. The study focuses on low concentration of Al2O3 dispersed in Water - Ethylene Glycol mixtures as coolant in a carbon graphite PEM fuel cell cooling plate. The study was conducted in a cooling plate size of 220mm x 300mm with 22 parallel mini channels and large fluid distributors. The mini channel dimensions are 100mm x 1mm x 5mm. A constant heat load of 100W was applied by a heater pad that represents the artificial heat load of a single cell. Al2O3 nanoparticle used was 0.1 and 0.5 vol % concentration which was then dispersed in 50:50 (water: Ethylene Glycol) mixture. The effect of different flow rates to heat transfer enhancement and fluid flow represented in Re number range of 20 to 120 was observed. Heat transfer was improved up to 13.87% for 0.5 vol % Al2O3 as compared to the base fluid. However the pressure drop also increase which result in pumping power increment up to 0.02W. The positive thermal results implied that Al2O3 nanofluid is a potential candidate for future applications in PEM fuel cell thermal management

Thermo-electrical performance of PEM fuel cell using Al2O3 nanofluids

Nanofluid adoption as an alternative coolant for Proton Exchange Membrane (PEM) fuel cell is a new embarkation which hybridizes the nanofluids and PEM fuel cell studies. In this paper, findings on the thermo-electrical performance of a liquid-cooled PEM fuel cell with the adoption of Al2O3 nanofluids were established. Thermo-physical properties of 0.1, 0.3 and 0.5% volume concentration of Al2O3 nanoparticles dispersed in water and water: Ethylene glycol (EG) mixtures of 60:40 were measured and then adopted in PEM fuel cell as cooling medium. The result shows that the cooling rate improved up to 187% with the addition of 0.5% volume concentration of Al2O3 nanofluids to the base fluid of water. This is due to the excellent thermal conductivity property of nanofluids as compared to the base fluid. However, there was a penalty of higher pressure drop and voltage drop experienced. Thermo electrical ratio (TER) and Advantage ratio (AR) were then established to evaluate the feasibility of Al2O3 nanofluid adoption in PEM fuel cells in terms of both electrical and thermo-fluid performance considering all aspects including heat transfer enhancement, fluid flow and PEM fuel cell performance. Upon analysis of these two ratios, 0.1% volume concentration of Al2O3 dispersed in water shows to be the most feasible nanofluid for adoption in a liquid-cooled PEM fuel cell

A review of nanofluid adoption in polymer electrolyte membrane (pem) fuel cells as an alternative coolant

Continuous need for the optimum conversion efficiency of polymer electrolyte membrane fuel cell (PEMFC) operation has triggered varieties of advancements, namely in the thermal management engineering scope. Excellent heat dissipation is correlated with higher performance of a fuel cell, thus increasing its conversion efficiency. This study reveals the potential advancement in thermal engineering of a fuel cell cooling system with respect to nanofluid technology. Nanofluids are seen as a potential evolution of nanotechnology hybridization with the fuel cell serving as a cooling medium. The available literature on the thermophysical properties of potential nanofluids, especially on the electrical conductivity property, has been discussed. The lack of electrical conductivity data for various nanofluids in open literature was another challenge in the application of nanofluids in fuel cells. Unlike in any other thermal management system, a nanofluid in a fuel cell is dealt with using a thermoelectrically active environment. The main challenge in nanofluid adoption in fuel cells was the formulation of a suitable nanofluid coolant with heat transfer enhancement, as compared to its base fluid, but still complying with the strict limits of electrical conductivity as low as 2 mS/cm and several other restrictions discussed by the researchers. It is concluded that a nanofluid in PEMFC is advantageous in terms of both heat transfer and simplification of the cooling system through radiator size reduction and potential elimination of the deionizer as compared to the current PEMFC cooling system. However, there are challenges that need to be well addressed, especially in the electrical conductivity requiremen

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

Performance and potential of a novel floating photovoltaic system in Egyptian winter climate on calm water surface

This article investigates the performance of a partially submerged floating photovoltaic system (PSFPV) as a proposal for harvesting solar energy as an electricity production novel system under Egyptian hot climate on calm water surfaces. The proposed system comprised of a floating photovoltaic system with a submerged portion in the surrounding water. The PSFPV system is constructed in addition to the water body and is then extensively examined under Egyptian outdoor conditions. The submerged portion of the PSFPV system keeps the system passively cool by being in direct contact with the surrounding water. A performance comparison between the novel PSFPV system and a similar land-based photovoltaic system (LPV) is also provided. The suggested PSFPV module's thermal and electrical performance was evaluated concerning its submerged length, which ranged from 4 to 24 cm. The results reveal that the PSFPV system achieves a reduction of about 15.10% in operating temperature relative to the LPV system. Also, the PSFPV system produces up to 20.76% more electricity than the LPV system. The PSFPV system is capable of alleviating the emission of CO2 by about 49.66 kg/summer season. The proposed PSFPV system reveals a reduction in the LCOE from 0.075 to 0.067 ($/kWh) by increasing the submerged length from 4 to 24 cm