This paper aims to perform the entropy analysis and thermal performance evaluation of a wavy-channels triplex-tube latent heat storage heat exchanger (LHSHE) during melting and solidification mechanisms. The system with different wave amplitudes was examined for different temperatures and Reynolds numbers of the heat transfer fluid (HTF). Water is passed in the inner and outer tubes in opposite directions

Enzyme production as well as rice straw saccharification and fermentation were integrated to produce bioethanol in this study. Submerged fermentation of Na2CO3 pretreated rice straw to produce a complex enzyme for saccharification by Aspergillus fumigatus was performed. The major component of rice straw, that is cellulose, hemicellulose and lignin was almost completely degraded in 24 h. Using whole

Offshore wind turbines in the vicinity of ship traffic are exposed to increased risks of ship collisions. To better understand the impact mechanism, this paper evaluates the dynamic responses of a monopile-supported wind turbine under ship impacts, using both numerical and analytical methods. The nonlinear finite element method is applied during the numerical simulations, and the wind load effects

In the present paper, a new hybrid model for transient heat transfer in Earth-Air Heat Exchangers (EAHE) based on thermal resistance capacity circuit is developed. To evaluate the performance of the EAHE, part of the solution field (soil around the pipe) is analytically solved. To assess the heat transfer in pipe and within the fluid inside the pipe, the solution field is divided into different layers

Solid acid catalyst was produced from olive pomace (OP), characterized and used for the esterification of OP oil. OP was pyrolyzed, physical activated by steam and sulfonated using sulfuric acid. Commercial, coconut husk-based, activated carbon (CHAC) was also sulfonated for comparison. The activation has shown a significant increase in olive pomace activated carbon (OPAC) surface area by developing

The operation stability demands for low and uniform wall temperature in the parabolic trough collector which acts as an energy conversion component in concentrating thermal conversion technology. In order to reduce the local high temperature with moderate pump power consumption, this paper proposed longitudinal swirls impinging cooling method. Three types of novel inclined curved-twisted baffles (A1

The transient characteristics associated with the machine load rejection process are investigated due to its close relationship with hydraulic facilities’ safety in low-head tubular turbines, especially in double-regulated bulb turbine. Load-rejection transient characteristics of a double regulated bulb turbine during the co-closing guide vanes (GVs) and runner blades (RBs) procedure were numerically

A novel vertical air-soil heat exchanger (VASHE) is proposed, coupling with diversified energy storage components, i.e., both annular and tubular phase change material (PCM) components. Compared to traditional air-soil heat exchanger systems, advantages of the new VASHE include the space-saving, higher energy efficiency, centralized discharge of condensate water and smaller fluctuation of outlet air

A multi-turbine condition monitoring method using supervisory control and data acquisition (SCADA) data for large-scale wind farm is proposed. The method takes the difference between the SCADA data of each turbine with the median of other remaining turbines, and establishes condition vector consisting of the differences. Considering the autocorrelation of turbine SCADA data, vector autoregression(VAR)

Variable-speed operation of a hydro turbine is considered as an alternative option to meet fluctuating energy demand as it allows high-ramping rate. Cavitation can be a limiting factor to utilize the variable-speed technology at fully capacity in a hydro power plant. This work investigates the cavitation characteristics and unsteady pressure fluctuations as turbine ramps up to meet the energy demand

A test platform for solar combined gas heating system was designed and established in Tianjin, control strategy for system operation was determined to meet domestic heating and hot water supply needs; basing on performance test, a series of evaluation indexes in energy saving, environmental protection and economic benefit for system operation were put forward; selecting 6 typical heating days in winter

The growing deployment of utility-scale photovoltaic (PV) in electricity industries raises many concerns for power system operation. Due to the highly variable and somewhat unpredictable characteristics of short-term PV output, the system operator faces challenges in balancing electricity supply and demand, which increases the need for short-term frequency management. Although many studies have been

Incoming solar radiation is a key factor influencing solar architecture design. It determines the thermal and optical regime of the building envelope and affects the solar heat and light transfer between the indoors and outdoors. Computational analysis is an essential tool in solar architecture design. Usually, an entire year’s weather data in a conventional weather file can be imported into such computational

To maintain economic and environmental sustainability, the study examines the influence of five major factors affecting renewable energy consumption. These five major factors include financial development, environmental pollution, innovation, economic freedom, and real GDP per capita in the ASEAN +3 economies during 1998–2018. By testing five hypotheses via the panel ARDL analysis and the Dumitrescu-Hurlin

The latent heat thermal energy storage system (LHTES) utilizes phase change material (PCM) to store energy. The non-uniformity in heat transfer between heat transfer fluid (HTF) and PCM along the height of the widely used vertical cylindrical shell and tube type storage tank causes a reduced thermal performance of the storage. Hence, in the present work, a passive heat transfer enhancement technique

European Union set an ambitious 20% target of its energy consumption from renewable resources 20% by 2020. The aim of this paper is to assess the contribution of solid biomass to renewables use in the EU. During 2010–2018 the share of solid biomass increased from 6.1% to 8.0% of total GFEC, an increase of almost 300 PJ. The paper identifies leading and lagging countries in biomass development by focusing

The development of alternative energy is considered as one of the ways to reduce the environmental pollution and carbon dioxide emissions. In Russia, the current level of development of alternative energy is not high. Russia requires the regulatory mechanisms that would contribute to the development of this energy sector. The objective of the article is to analyze and determine the directions for improving

Multi-component thermodynamic equilibrium predictions of coconut husk combustion products were performed in this work. The calculation results showed that the concentration of the chlorine species in the flue gas and ash were clearly influenced by the combustion temperature. At temperatures below 820ºC the highest concentration was HCl(g), and above 820ºC was KCl(g). Chlorine species were also observed

Pitch angle greatly affects the performance of VAWT. Aiming at the maximum value of CT, this study first obtains the theoretical optimal angles of attack, i.e., 17.7° and −18.4° in upwind and downwind zones. A 2.5D model is simulated using Fluent to determine the magnitude and direction of induced velocity, and an initial pitch angle adjustment law is obtained combining the proposed local TSR. Compared

This paper proposes a radial-grouping-based planning method for the electrical collector systems (ECSs) to design the topology and select the cross-sections of ECS submarine cables in tidal current generation farms (TCGFs) while minimizing investment and operation costs. First, an angle-based radial-grouping method is proposed to group the tidal current turbines (TCTs) in a TCGF, considering their

The Brazilian as well as the global energy matrix is still mostly supported by non-renewable energy sources such as oil. However, the national energy scenario has a much higher renewable share, and this behavior is largely due to the fact that the country has abundant renewable resources. The immediate availability of renewable grease in Brazil fell on soybeans, the main Brazilian agricultural crop

The study investigates linkages between financial development, income inequality and renewable energy consumption from 39 countries in Sub-Saharan Africa. The empirical evidence is based on data for the period 2004–2014, Generalized Method of Moments (GMM) and Quantile Regressions (QR). The GMM results show that financial development unconditionally promotes renewable energy consumption while income

For medium-scale dispatchable (on demand) power and fresh water generation, a concentrated solar energy powered system with thermal energy storage is an attractive option. However, currently used concentrated solar power technologies (parabolic trough collector, solar power tower, linear Fresnel reflector) use heavy and very expensive glass mirrors and receivers. Recently, a novel micro-structured

Optimization of photovoltaic (PV) panel orientation is a significant part of economic evaluation. However, designing a PV system according to only one theoretical optimal orientation is challenging. Installing a PV panel at a specific orientation can cause low economic efficiency, depending on the features of the area. Therefore, in this study, a new term—the tolerance angle—is introduced for quantitatively

In order to find out the effect mechanism of the cavitation on the hump characteristic of pump-turbines, three dimensional numerical simulations with and without cavitation were carried out using the SST (shear stress transport) k-ω turbulence model and ZGB (Zwart-Gerber-Belamri) cavitation model. Numerical results agreed well with the performance characteristic and flow visualization results. Under

The installation potential of a ground source heat pump (GSHP) system was highly affected by site geological conditions. A certain type of geological unit maintains similar geological settings geospatially. It is of importance to demonstrate a case to characterize the geological background and the associated geothermal potential to properly plan and sustainable development of geothermal resources.

In this paper, an anionic functionalized ionic liquid antioxidant [MI][C6H2(OH)3COO] was designed and synthesized by a two-step method. The structure was characterized by 1H NMR and Fourier transform infrared spectroscopy. The mechanism and antioxidant properties of the ionic liquid antioxidants were studied, and the effect on the catalytic oxidation characteristics of iron and copper ions in biodiesel

Under the dual stimulus of the new energy demand and the increasing competitiveness of wind energy, the construction of wind speed prediction models began to be placed in a position that cannot be ignored. To overcome the challenges brought by wind speed fluctuations to wind speed forecasting, this paper proposes a novel hybrid wind speed forecasting deep model. The model has three modules, including

At present, accurate forecast of very-short-term wind speed is still a critical issue, mainly due to the complex characteristics of wind variations such as intermittence, fluctuation and randomness. On this topic, our paper contributes to the development of an effective multi-step forecasting method termed ECKIE, which provides multi-step forecast for the very-short-term wind speed in specific stations

The sluggish kinetics of the four-electron-proton coupled oxygen evolution reaction (OER) limits the efficiency of water splitting. Herein, Ni–S–CoFe2O4 magnetic nanosheets supported on Ni Foam (Magn-Ni-S-CoFe2O4/NF) as highly active OER electrocatalysts are synthesized via an extremely simple magnetic-field guided co-electrodeposition strategy. With the application of magnetic fields, the flower-like

Optimal management for solar energy systems requires quality data to build accurate models for predicting the behavior of solar radiation. Solar irradiance and environmental data are provided by satellite and in-situ measurements. It is usual that satellite measurements present high temporal resolution with limited spatial resolution, and in-situ measurements provide high accuracy but significant missing

CdTe PV cell is one perfect candidate for window application because of its good daylighting performance, low-temperature coefficient and excellent electrical performance under weak light. In addition, thermal catalytic oxidation is an thermal driven air purification technology and the thermal energy can be easily obtained from PV window systems. Therefore, a novel thermal-catalytic CdTe double-layer

Solar powered irrigation system (SPIS) irrigation has emerged as a promising technology in Bangladesh. The aim of this study to find the financial and environment importance of SPIS. This study also analyzes the factor demand and elasticity of substitute for SPIS irrigation in Boro rice production. The financial analysis indicate that SPIS user had significantly higher gross return, net return and

China, India, and the USA are the world’s biggest energy consumers and CO2 emitters. Being the leading contributors to climate change, these economies are also at the core of environmental solutions. This paper investigates the causal relationship among solar and wind energy production, coal consumption, economic growth, and CO2 emissions for these three countries. To do so, we use an advanced methodology

Energy transition is prevalent nowadays, and Colombia is no exception to this phenomenon. Energy coming from non-conventional renewable resources is one of the main feature of this phenomenon. Consequently, this paper evaluates the impact of this new kind of renewable energy resource in the Colombian wholesale electricity market. This evaluation uses a counterfactual scenario based on a structural

This work describes the thermal behavior and evaluation of kinetics drying of natural rubber sheets using two solar drying technologies: direct and indirect. The solar drying tests were carried out simultaneously in order to compare the behavior under same weather conditions. The moisture content of the rubber sheets was reduced from 45.8 to 0.59% and from 49.7 to 0.33% on a dry basis (d.b.) for direct

Solar panels have not seen the same widespread adoption in the Nordic countries as in the rest of Europe. The aim of the paper is to investigate how house owners that have already expressed some interest in solar panels form an intention to become pilot customers in an innovative scheme to install solar panels. The main theoretical perspective for the analysis is the Theory of Planned Behaviour, expanded

The enhancement of aerodynamic performance of airfoil using Gurney flap was demonstrated and due to its effects of lift increasing and stall suppression on airfoil, Gurney flap has positively functioned in a wide range of engineering. Though there had been numerous scholars who aroused wide concern on geometric parameters of Gurney flap for airfoil, the investigation of geometric design of Gurney flap

As energy system will increasingly become renewable, they will face new challenges that mainly arise due to the varying output by many renewable energy technologies. An issue that is especially prominent for countries with high shares of hydropower in their electricity generation is the varying yearly output of these technologies. This work aims to propose a techno-economically optimized energy system

The large-scale commercial application of phase change materials (PCMs) was seriously limited by the leakage, poor heat storage capacity and slow thermal response behavior. To address these issues, stearic acid/graphene oxide-attapulgite aerogel (SA/HGA-ATP) shape-stabilized PCMs were fabricated via hydrothermal method. The morphology, structural characteristics, thermal properties were determined

In the present study, pyrolysis kinetics of the pure and blends of cedar wood (CW), algal biomass (AB), and digested sludge (DS) with and without the catalyst ZSM–5 were examined. Both Kissinger-Akahira-Sunose (KAS) and Flynn-Wall-Ozawa (FWO) model-free methods were used to calculate the total activation energy (Ea), change in enthalpy (ΔH), and change in Gibb’s free energy (ΔG) of 18 different biomass

Electrochemical water splitting has brought clean route of green energy generation through its hydrogen evolution capability having no environment impact in the form of global warming. The related technology experiences challenges associated with cost, durability and mass production of hydrogen separated from water. Proper morphological design of highly active and low cost materials for both electrodes