02 - LIDSEN Publishing Inc.丨The Open Access Publisher

Volume 4,Issue 2

Open Access Original Research

Analysis of LoRa Transmission Delay on Dynamic Performance of Standalone DC Microgrids

Cherechi Ndukwe ,

Tariq Iqbal ,

Jahangir Khan and

Mohsin Jamil

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

Abstract

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 c [...]

Open Access Research Article

Controller Evaluation for Solar-Latent Thermal Energy Applications

John Konstantaras ,

Christos Pagkalos ,

Maria Koukou ,

Kostas Lymperis ,

Yannis Caouris and

Michail Vrachopoulos

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

Abstract

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 capa [...]

Open Access Original Research

Improving the Engine Efficiency Using a New Combined Refrigeration Cycle for Low-Temperature Heat Source (Waste Heat Recovery)

Koorosh Goudarzi and

MohammadReza Zare

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

Abstract

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 [...]

Open Access Research Article

Analysis of Correlations for the Prediction of the Entrainment Fraction of Droplets in Gas-liquid Annular Flows

Mariana P. Koss and

Luiz E. M. Lima

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

Abstract

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 co [...]

Open Access Original Research

Non-Newtonian Flow in Bifurcated Piping and Arterial Networks

Jamie Chin and

Wilson Chin

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

Abstract

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 h [...]

Open Access Original Research

A Large Eddy Simulation Study of Cyclones: The Effects of Interparticle Collisions on Erosion Prediction

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

Abstract

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-p [...]

Open Access Research Article

Experimental Study of Lean-burning Limits of Hydrogen-enriched LPG Intended for Domestic Use

Udaya Kahangamage ,

Yi Chen ,

Chun Wah Leung and

Tung Yan Ngai

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

Abstract

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 inc [...]

Open Access Short Communication

Electrochemical Impedance Spectroscopic Studies of PHEV2 form-factor Lithium-ion Cells for Automotive Applications

Simon Calles ,

Paul Heitjans and

Alexander Börger

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

Abstract

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 sho [...]

Open Access Research Article

Solar Energy Policy for Commercial Buildings Sector: Recommendations for the Indian Scenario

Meenal Jain ,

Meenakshi Mital and

Matt Syal

Received: 21 November 2021; Published: 14 April 2022; doi: 10.21926/jept.2202014

Abstract

India is a rapidly developing nation and is heavily dependent on fossil fuels. Renewable energy presents an attractive solution to the growing challenges concerning energy needs. Solar energy is abundant in India, and thus, its application and use are rapidly advancing. This study assesses various government initiatives for off-grid Solar Photovoltaic/Solar Water Heating systems for commercial establishments in India and elucidates the need for improvements in their implementation, h [...]

Open Access Original Research

Adapted Time Slice Model of Pinch Analysis for Direct-Indirect Heat Recovery in Buildings

Hossein Akbari ,

Seyed Mojtaba Hosseinnia ,

Mikhail Sorin ,

James Christopher Reddick and

Dominic Laperle

Received: 13 January 2022; Published: 12 April 2022; doi: 10.21926/jept.2202013

Abstract

Heat integration techniques such as pinch analysis can play a significant role in saving energy in the design of buildings. The application of pinch analysis in this sector encounters difficulties due to the highly time-dependent behavior of energy streams such as waste heat and solar thermal collectors, as well as the possible need for heat storage units (HSUs). The existing pinch models in the literature either bear little relation [...]

Open Access Original Research

Building New Nuclear in Finland: Crises Challenging Core Beliefs around Nuclear Energy

Lotta Lounasmeri

Received: 26 November 2021; Published: 06 April 2022; doi: 10.21926/jept.2202012

Abstract

This paper examines the building of a new nuclear plant as a greenfield operation in Pyhäjoki, Finland. A newly-founded energy company, Fennovoima, was granted a license by the Finnish parliament to build a new power plant in 2010. In the years following this Decision in Principle the project faced several obstacles. Through interviews with key actors, this paper identifies the interests and core beliefs associated with building the plant. It posits that, in Finland, the underlying ideas and val [...]

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