by Jeggathishwaran Panisilvam  , Peng Cheng Wang  and Hui An

Received: 26 March 2022;  Published: 13 July 2022;  doi: 10.21926/jept.2203024

Reducing and conserving fuel usage is pivotal for any engineering system for the development of a sustainable energy solution. Proton exchange membrane fuel cells (PEMFCs) are one of the promising renewable energy systems that consume hydrogen as their source of fuel to generate electricity. This paper investigate the necessity of the constant supply of fuel (hydrogen) in the PEMFC system to ensure stable operation. We propose that a dynamic supply of fuel could help achieve similar performance and reduce the amoun [...]

by Clara L.e Silva  , Bárbara H.S. Miranda  , Maria L. Vilela  , Jair F. Rodrigues  , Thainá G. Cunha  , Jhonatan A. Dias  , Gabriela A. Soares  , Vinicius Freitas  , Rodrigo de Q. Vilaça  , Luana Wouk  and Diego Bagnis

Received: 07 March 2022;  Published: 04 July 2022;  doi: 10.21926/jept.2203023

The lifetime and stability of organic photovoltaics (OPVs) are the key factors that influence the technology used to scale up and commercialize OPVs. High-performing and reliable devices are used to fabricate the devices of choice. Materials and methods that can be used to prevent the degradation of organic materials, enabling better OPV applications, are being increasingly researched in recent years. Herein, we present the surface modification process of a commercial, flexible barrier film based on polyethylene te [...]

by Cherechi Ndukwe  , M. Tariq Iqbal  , Jahangir Khan  and Mohsin Jamil

Received: 18 April 2022;  Published: 26 June 2022;  doi: 10.21926/jept.2202022

One important aspect toward proper and stable functioning of a communication-based controlled microgrid is data transmission. Consequently, an analysis of the effect of data transmission delay is of significance for any chosen communication protocol. This paper focuses on the effect of employing LoRa for data transfer at the secondary control level of a standalone DC microgrid. It analyses the effect of LoRa transmission delay on the dynamic performance of DC microgrids. This paper simulates a community DC microgri [...]

by John Konstantaras  , Christos Pagkalos  , Maria K. Koukou  , Kostas Lymperis  , Yannis Caouris  and Michail Gr. Vrachopoulos

Received: 17 April 2022;  Published: 09 June 2022;  doi: 10.21926/jept.2202021

In this study, the performance of a self-sufficient controller used for a solar-latent heat domestic hot water (DHW) production unit under real-world operating conditions was analyzed. The unit consists of a flat-plate solar collector and a latent heat storage tank. The controller is powered by a small solar panel and governs the charging and discharging of the system, ensuring maximum solar energy absorption, desired hot water temperature, and constant monitoring of the heat-storage tank’s capacity. The system is [...]

by Koorosh Goudarzi  and Mohammad Reza Zare

Received: 19 April 2022;  Published: 08 June 2022;  doi: 10.21926/jept.2202020

Passenger and commercial internal combustion engines have relatively large dissipated thermal energy sources that can be used for initiating thermodynamic refrigeration cycles at low temperatures while improving engine efficiency. Researchers have focused on combined power-refrigeration cycles in past studies. This paper presents the operation and performance of a new combined refrigeration system driven by waste heat recovery within the internal combustion engines. For this purpose, the effects of several paramete [...]

by Mariana P. Koss  and Luiz E. M. Lima

Received: 14 February 2022;  Published: 24 May 2022;  doi: 10.21926/jept.2202019

In gas-liquid flows, droplets that detach from the liquid film lining the internal walls of a pipe and merge with the gas flowing through the pipe follow an annular flow pattern. This work analyzes correlations for estimating the entrainment fraction of such droplets contained in the literature by comparing their predictions with experimental data also from the literature. The results of this comparative study demonstrate that the analyzed correlations do not accurately reproduce experimental conditions. This is du [...]

by Jamie A. Chin  and Wilson C. Chin

Received: 12 February 2022;  Published: 23 May 2022;  doi: 10.21926/jept.2202018

Flows in multi-branch piping systems are modeled for linear Newtonian and nonlinear Power Law, Bingham Plastic and Herschel-Bulkley fluids. The nonlinear models are often used to describe multiphase fluids consisting of liquid and solid phases, including cement slurries and drilling muds in petroleum engineering. Rheological and heterogeneous multiphase effects are important to blood flows in single and bifurcated arteries, capillaries and veins – biological applications are also emphasized to highlight their incre [...]

by Diego Alves de Moro Martins  , João Rodrigo Andrade  , Carlos Antonio Ribeiro Duarte  , Ricardo de Vasconcelos Salvo  and Francisco José de Souza

Received: 31 January 2022;  Published: 06 May 2022;  doi: 10.21926/jept.2202017

Cyclone separators are widely used in fluid catalytic cracking (FCC) units due to their lack of moving parts and relatively low-pressure drop. However, cyclone separators are prone to erosion-related issues, which is a major drawback. In this paper, a large eddy simulation (LES) of the particle-gas flow in a cyclone separator is investigated using a four-way Euler-Lagrange approach to model inter-particle collisions and the exchange of momentum between particles and fluid. The effects of inter-particle and particle [...]

by Udaya Kahangamage  , Yi Chen  , Chun Wah Leung  and Tung Yan Ngai

Received: 02 January 2022;  Published: 18 April 2022;  doi: 10.21926/jept.2202016

The lean-burning limits of hydrogen-enriched Liquefied Petroleum Gas (LPG) have been studied using a Bunsen burner. The lean-burning limits under different conditions are important design considerations in developing gas-fired domestic appliances. In this study, the lean-burning limits of hydrogen-enriched LPG have been obtained across a wide range of Reynolds numbers (600 to 1800) and H2 volumetric fractions (0% to 25%). The results show that the lean-burning limit is increased, on average, by 4.0% to 7.2% for eve [...]

by Simon Calles  , Paul Heitjans  and Alexander Börger

Received: 09 November 2021;  Published: 18 April 2022;  doi: 10.21926/jept.2202015

Prismatic PHEV2 form-factor lithium-ion cells with a nominal capacity of 25 Ah (as used for automotive applications) have been studied with electrochemical impedance spectroscopy (EIS). The data was evaluated using electrical equivalent circuits. Mathematical modeling, system identification, and the determination of model parameters of the lithium-ion cell were also carried out. While a study of the influence of temperature and state-of-charge (SOC) performed using pristine lithium-ion cells showed a nonlinear rela [...]