Article
Thermodynamics
Kun Hong, Yang Yang, Saman Rashidi, Yu Guan, Qingang Xiong
Summary: This study numerically investigated the thermal and flow characteristics of a parabolic-trough solar collector, showing that an increase in Cu nanoparticle concentration led to an increase in Nu and that the effect on heat transfer enhancement was more significant at lower Reynolds numbers. The study also assessed the impact of direct normal irradiance changes on the performance of the solar collector.
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
(2021)
Article
Green & Sustainable Science & Technology
Ibrahim Halil Yilmaz, Aggrey Mwesigye, Fatih Kilic
Summary: Parabolic trough solar collectors (PTSCs) are widely used in various fields, and the selection of heat transfer fluid (HTF) is crucial for their design and performance. This study proposes an integrated decision-making approach using AHP-VIKOR and CFD to prioritize HTFs in PTSC applications, and the results suggest that water and molten salt (Hitec) should be given priority in current systems.
Article
Thermodynamics
Victor Jorge de Oliveira Marum, Livia Bueno Reis, Felipe Silva Maffei, Shahin Ranjbarzadeh, Ivan Korkischko, Rafael dos Santos Gioria, Julio Romano Meneghini
Summary: A quasi-1D mathematical model coupled with CFD simulations of a water ejector was presented, which was used to calculate friction loss coefficients, predict efficiency, and determine operational envelope. The CFD approach was validated with experimental data, showing that the k-omega SST turbulence model is the most suitable for capturing ejector flow characteristics under different operational conditions.
Article
Computer Science, Interdisciplinary Applications
Amal El Kouche, Francisco Ortegon Gallego
Summary: This paper describes the mathematical modeling of a parabolic trough collector with temperature dependent physical properties, and the numerical simulations conducted to provide valuable information on the performance and efficiency of a solar PTC plant at a specific location.
MATHEMATICS AND COMPUTERS IN SIMULATION
(2022)
Article
Thermodynamics
Behzad Vahedi, Ehsan Golab, Arsalan Nasiri Sadr, Kambiz Vafai
Summary: The study analyzed the effectiveness of using a glass cover in a parabolic trough collector system to reduce heat losses at low Reynolds numbers. Considering temperature-dependent properties of the oil can greatly reduce the friction factor in the system.
APPLIED THERMAL ENGINEERING
(2022)
Article
Thermodynamics
Shaobing Wu, Runsheng Tang, Changmei Wang
Summary: The numerical algorithm proposed for calculating the intercept factors of a parabolic trough solar collector was found to provide quick and convenient results, which are accurate for various types of secondary reflection concentrators.
Article
Engineering, Multidisciplinary
Jawed Mustafa, Saeed Alqaed, Mohsen Sharifpur
Summary: The influences of a helical absorber tube on the thermal performances of a double-fluid parabolic trough solar collector occupied by non-Newtonian nanofluid are investigated numerically. The results show that the volume fraction and nanoparticle diameter of the nanofluid have significant effects on the efficiency of the collector, and an artificial neural network can accurately predict the efficiency.
ENGINEERING ANALYSIS WITH BOUNDARY ELEMENTS
(2022)
Article
Energy & Fuels
Ridha Chargui, Bourhan Tashtoush, Sami Awani
Summary: This study presents an experimental evaluation of a new design of a parabolic trough solar collector, which achieved significant improvements in maximizing energy yield and system thermal efficiency compared to other designs. An economic study indicated a gross payback period of 3.3 years, demonstrating promising economic feasibility.
INTERNATIONAL JOURNAL OF ENERGY RESEARCH
(2022)
Article
Green & Sustainable Science & Technology
Xiaowen Liu, Mehdi Vahabzadeh Bozorg, Qingang Xiong, Weidong Li
Summary: Parabolic trough solar collector (PTSC) is a widely used and cost-effective solar energy absorption device in Belt and Road Initiative countries. However, its thermal efficiency is relatively low due to high thermal loss. This study investigates the addition of copper nanoparticles to the heat transfer fluid and the installation of non-porous fins inside the receiver to improve performance. Computational fluid dynamics is used to analyze heat transfer and the results show that the addition of internal fins significantly enhances heat transfer coefficient and the addition of copper nanoparticles slightly increases thermal efficiency.
JOURNAL OF CLEANER PRODUCTION
(2022)
Article
Thermodynamics
Rohit Goyal, K. S. Reddy
Summary: Parabolic trough collector is a widely used and efficient technology for generating solar thermal power. The use of supercritical CO2 as a heat transfer fluid shows great potential for improving its efficiency. A numerical thermal model and optical analysis were used to analyze the entropy generated by s-CO2 in a parabolic trough collector and determine the optimal operating conditions.
APPLIED THERMAL ENGINEERING
(2022)
Review
Green & Sustainable Science & Technology
Arun Kumar Tiwari, Vijay Kumar, Zafar Said, H. K. Paliwal
Summary: The Parabolic trough collector (PTC) is the most established solar concentration technology worldwide. The study compares various researches to evaluate the effect of nanofluids on thermal parameters for PTC and suggests that using hybrid nanofluids can significantly enhance thermal properties. Metal oxide hybrid nanofluids show more promise in enhancing thermal conductivity compared to oxide ones.
JOURNAL OF CLEANER PRODUCTION
(2021)
Article
Thermodynamics
Waleed Al-Aloosi, Yaser Alaiwi, Hudhaifa Hamzah
Summary: This research employed numerical simulations to study the turbulent flow in a modified parabolic trough solar collector with inserted fins. The purpose of incorporating these fins was to improve heat transfer efficiency. The simulations showed that all modified models had higher thermal performance than the reference model, with the sixth model achieving a maximum thermal performance of 1.4. Additionally, different cross-sectional areas of fins, including circular, elliptical, and square, were examined, with circular fins achieving the highest thermal performance of 1.4.
CASE STUDIES IN THERMAL ENGINEERING
(2023)
Article
Thermodynamics
Wieslaw Zima, Piotr Cisek, Artur Cebula
Summary: The paper presents an in-house mathematical model for simulating an innovative double U-tube sun-tracked Parabolic Trough Collector designed for low-temperature applications. Experimental verification shows a fully satisfactory agreement between measurement and computational results, validating the high efficiency of the proposed model. The main advantage of the model is its simplicity and low computational cost, enabling its online application.
Article
Green & Sustainable Science & Technology
Ahmadreza Najafi, Ali Jafarian, Ahmad Arabkoohsar
Summary: This study introduces a detailed three-dimensional numerical modeling of solar parabolic trough collectors and compares it to one-dimensional and axisymmetric models to showcase the impact of a rigorous model on accuracy. The results indicate that while axisymmetric and nodal models show acceptable accuracy in temperature and enthalpy predictions, they lack precision in calculating vapor volume fraction and heat loss rates, leading to significant temperature heterogeneity in the solid walls.
SUSTAINABLE ENERGY TECHNOLOGIES AND ASSESSMENTS
(2021)
Article
Green & Sustainable Science & Technology
M. Medhat El-Bakry, Mahmoud A. Kassem, Muhammed A. Hassan
Summary: Boosting the optical and thermal efficiencies of parabolic trough concentrators is gaining global interest. This study proposes a new design with floating radiation heat shields to enhance energy and exergy efficiencies. The configuration with a diameter of 75 mm and a shading angle of 150 degrees showed the highest improvement ratios.
Article
Energy & Fuels
Pawel Oclon, Janusz Pobedza, Pawel Walczak, Piotr Cisek, Andrea Vallati
Article
Green & Sustainable Science & Technology
Pawel Oclon, Piotr Cisek, Marcelina Matysiak
Summary: The circular economy is a closed cycle system that allows for the reuse of industrial waste and reduction of energy and resource losses during production. This paper introduces an innovative application of geopolymer as a backfill material for underground power cable systems. Utilizing geopolymer backfill can reduce material costs and improve the flexibility of underground power cable systems.
CLEAN TECHNOLOGIES AND ENVIRONMENTAL POLICY
(2021)
Article
Thermodynamics
Pawel Oclon, Piotr Cisek, Ewa Kozak-Jagiela, Jan Taler, Dawid Taler, Dorota Skrzyniowska, Malgorzata Fedorczak-Cisak
ENERGY CONVERSION AND MANAGEMENT
(2020)
Article
Energy & Fuels
Bartosz Rozegnal, Pawel Albrechtowicz, Piotr Cisek
Summary: The operating principle of the new selective circuit breaker allows for an increased selection range, especially for networks with high short-circuit loop impedance and reduced supply voltage. This solution will not excessively limit the short-circuit current, ensuring the correct reaction of the preceding protection systems.
Article
Thermodynamics
Wieslaw Zima, Piotr Cisek, Artur Cebula
Summary: The paper presents an in-house mathematical model for simulating an innovative double U-tube sun-tracked Parabolic Trough Collector designed for low-temperature applications. Experimental verification shows a fully satisfactory agreement between measurement and computational results, validating the high efficiency of the proposed model. The main advantage of the model is its simplicity and low computational cost, enabling its online application.
Article
Engineering, Electrical & Electronic
Pawel Albrechtowicz, Piotr Cisek
Summary: This article discusses the application of phase-shifting transformers in power systems and emphasizes the importance of considering line resistance in power flow calculations. The impact of line resistance on the final power flow calculations is demonstrated through examples and test results, highlighting the omission of resistance effects in some literature.
ELECTRIC POWER SYSTEMS RESEARCH
(2022)
Article
Energy & Fuels
Pawel Albrechtowicz, Bartosz Rozegnal, Piotr Cisek
Summary: This article presents different types of phase shifting transformers (PSTs) and their effects on transmitted power and energy parameters. By comparing various PSTs, it is found that the asymmetrical controllable phase shifting transformer (ACPST) has good regulation capabilities and practical value. Experimental data shows that although the asymmetrical phase shifting transformer (APST) allows high power transfer, the voltage increase in some cases exceeds acceptable limits, while the symmetrical phase shifting transformer (SPST) exhibits the best properties in terms of power transfer, output voltage, and internal voltage drop in the tests.
Article
Thermodynamics
Wieslaw Zima, Jan Taler, Slawomir Gradziel, Marcin Trojan, Artur Cebula, Pawel Oclon, Piotr Dzierwa, Dawid Taler, Monika Rerak, Marek Majdak, Anna Korzen, Dorota Skrzyniowska
Summary: The article presents the development of a comprehensive methodology for thermal-flow computations of a natural circulation power boiler. In-house methods were developed for heat transfer calculations in the boiler, and a computer program was created to perform the computations. The results were compared with data from the boiler manufacturer, showing small differences that confirm the accuracy of the proposed methodology and mathematical models.
Article
Thermodynamics
Jan Taler, Marcin Trojan, Piotr Dzierwa, Karol Kaczmarski, Bohdan Weglowski, Dawid Taler, Wieslaw Zima, Slawomir Adziel, Pawel Oclon, Tomasz Sobota, Monika Rerak, Magdalena Jaremkiewicz
Summary: This study determines the high flexibility requirement of thermal steam units cooperating with wind and photovoltaic farms, as well as experiments on the heating rates of thick-walled components. The simulations also confirm that the emissions of harmful substances from the unit at different loads comply with European regulations.
Article
Thermodynamics
Wieslaw Zima, Slawomir Gradziel, Artur Cebula, Monika Rerak, Ewa Kozak-Jagiela, Marcin Pilarczyk
Summary: This study developed a mathematical model of a natural circulation coal-fired power plant to analyze the feasibility of its cooperation with renewable energy sources. The accuracy of the model results was verified through experiments, and a new method to simulate the heating of multiple surfaces in a flue gas duct was proposed.
Article
Energy & Fuels
Pawel Albrechtowicz, Bartosz Rozegnal, Jerzy Szczepanik, Maciej Sulowicz, Piotr Cisek
Summary: This article presents a new solution for a phase-shifting transformer, which is shown to be more functional and improved compared to other existing structures. The construction and operation of the proposed device are compared to other solutions, and computer simulations and laboratory tests confirm the effectiveness of the new transformer. Power flow calculations in an electrical power system model also demonstrate the constant active power flow of the proposed structure. The authors highlight that their solution combines the advantages and functionality of different types of phase shifters, while being simpler and more cost-effective.
Article
Thermodynamics
Wieslaw Zima, Grzegorz Ojczyk
Summary: This paper presents a test stand equipped with two boilers, one for burning wood pellets and the other for mainly burning hard coal but also capable of burning wood pellets. The paper discusses the testing results of burning wood pellets in the multi-fuel boiler and analyzes the flue gas temperature, carbon monoxide, and oxygen content.
ARCHIVES OF THERMODYNAMICS
(2022)
