Article
Chemistry, Multidisciplinary
Miqdam T. Chaichan, Hussein A. Kazem, Moafaq Al-Ghezi, Ali Al-Waeli, Ali J. Ali, Kamaruzzaman Sopian, Abdul Amir Kadhum, Wan Nor Roslam Wan Isahak, Mohd S. Takriff, Ahmed A. Al-Amiery
Summary: In this study, multiwalled carbon nanotubes were used as added particles in nanofluids to investigate the most suitable nanofluid for cooling PVT systems in extreme summer environments. The parameters of base fluid, surfactant, and sonication time were examined. Water was chosen as the base fluid instead of other potential candidates. The nanofluid tested in Baghdad city resulted in significant enhancements in thermal conductivity compared to other fluids, and the nanofluid-cooled PVT system showed higher electrical and thermal efficiencies than standalone PV technology and water-cooled PVT systems.
Article
Thermodynamics
Shixian Zeng, Rui Xue, Roozbeh Sabetvand
Summary: This study investigates the heat transfer of copper nanoparticles and ammonia refrigerant in a nanochannel using molecular dynamics simulation. The results demonstrate that increasing the electric field frequency leads to a longer phase change time and a lower thermal conductivity. The study also examines the effect of different cavities on the atomic and thermal behavior of the simulated samples, revealing that samples with cubic cavities exhibit the highest thermal conductivity.
INTERNATIONAL COMMUNICATIONS IN HEAT AND MASS TRANSFER
(2022)
Article
Engineering, Environmental
Clara Kay Leng Ng, Ming Liu, Jasmine Siu Lee Lam, Mengyao Yang
Summary: Ammonia is considered a potential marine fuel, and its bunkering operation in major ports, including Singapore, raises concerns due to its toxic nature. A safety study was conducted to simulate the dispersion and consequences of accidental ammonia release during bunkering, with results revealing that storing ammonia as a fully-refrigerated liquid at atmospheric pressure is safest. Vertical ammonia release should be avoided, as it leads to the most severe consequences, while reducing release duration and flow rate can significantly decrease severity. Additionally, ammonia dispersion over water is greater during the day than at night.
JOURNAL OF HAZARDOUS MATERIALS
(2023)
Article
Energy & Fuels
Ray Soujoudi, Randall Manteufel
Summary: This paper evaluates the use of flash intercooling (FIC) in the precooling cycle to enhance the efficiency of the liquefaction process. Propane and ammonia are examined as precooling refrigerants, and energy and exergy analyses are conducted for eight case studies. The results show that FIC significantly reduces the energy consumption of the process and has a greater impact at higher ambient temperatures. The findings from the exergy analysis reveal that compressors and heat exchangers are the major contributors to exergy destruction.
Review
Chemistry, Multidisciplinary
Marcel Ulrich Ahrens, Maximilian Loth, Ignat Tolstorebrov, Armin Hafner, Stephan Kabelac, Ruzhu Wang, Trygve Magne Eikevik
Summary: Decarbonization of the industrial sector is crucial for reducing global warming. Utilizing high temperature heat pumps with natural fluids, such as ammonia-water absorption-compression heat pumps, shows great potential for increasing energy efficiency and reducing emissions in industrial processes. This study reviews the state of technology, identifies existing challenges, and highlights recent developments and promising solutions for ammonia-water ACHP systems at high temperature operation.
APPLIED SCIENCES-BASEL
(2021)
Article
Chemistry, Physical
Xiaoling Liu, Indrajit Patra, Oleg R. Kuzichkin, Muhaned Zaidi, Shuaib M. Abdulnabi, Zainab Mohsen Najm, Usama S. Altimari, Salema K. Hadrawi, Mansour Taheri Andani, Maboud Hekmatifar
Summary: The study investigated the thermal behavior of ammonia refrigerant with Cu nanoparticles in a nanochannel, simulating parameters such as velocity and temperature profiles, aggregation time, and heat flux. Results showed that increasing electric field amplitude and changing cavity structures affected the heat transfer performance.
JOURNAL OF MOLECULAR LIQUIDS
(2022)
Article
Chemistry, Physical
Kai Kang, Yaxiu Gu, Xiaopo Wang
Summary: A modified Quantitative Structure Property Relationship (QSPR) theory is proposed to estimate reliable binary interaction parameters (k(ij)). The model shows good performance in predicting phase behavior and viscosity, especially for highly nonideal systems.
JOURNAL OF MOLECULAR LIQUIDS
(2022)
Article
Mechanics
Gholamreza Kefayati, Andrew P. Bassom
Summary: Nanofluids are used in various industries to improve heat transfer, and their modeling and simulation are continuously evolving. This study introduces a lattice Boltzmann method for simulating both Newtonian and non-Newtonian nanofluids, with the potential to incorporate any format of extra tensor directly. The method is suitable for studying non-Newtonian nanofluids and has been validated against benchmark problems involving both types of fluids.
Article
Thermodynamics
Ray Soujoudi, Randall Manteufel
Summary: This study examines the benefits and drawbacks of mixing ammonia with lighter hydrocarbon refrigerants in a natural gas liquefaction's precooling cycle, showing that the presence of ammonia in the mixed refrigerant can save capital costs and reduce precooling operation expenses, while also enhancing cycle efficiency. The results highlight the potential of reducing molar concentration of pollutant refrigerants and replacing with ammonia to improve energy efficiency and reduce heat exchanger losses.
Article
Chemistry, Physical
Jiheng Ding, Hongran Zhao, Haibin Yu
Summary: The study developed a method to synthesize edge-selective sulfonic-acid functionalized graphene (ESfG) with high yield, which showed a thermal conductivity of 3.11 W/mK in water-based nanofluids, the highest recorded to date. The ESfG aqueous nanofluids exhibited much higher heat transfer capability compared to water and also demonstrated high storage stability, making it a promising candidate for high-performance thermally conductive nanofluids in efficient thermal management applications.
Article
Thermodynamics
Tomasz Halon, Bartosz Gil, Bartosz Zajaczkowski
Summary: This paper summarizes the search for suitable alternatives to commonly used refrigerants in vapor compression air conditioning systems for a moderate climate. Through simulations and screening, it was found that R152a/R1234ze(E) [0.7/0.3 mass ratio] is the best refrigerant blend.
APPLIED THERMAL ENGINEERING
(2022)
Article
Environmental Sciences
Zdzislaw Salamonowicz, Malgorzata Majder-Lopatka, Anna Dmochowska, Wioletta Rogula-Kozlowska, Aleksandra Piechota-Polanczyk, Andrzej Polanczyk
Summary: Air pollution is a global problem that causes millions of premature deaths each year. This study analyzed the distribution of ammonia in an engine room and found that emergency ammonia leakage poses a significant threat to machinery and spreads throughout the building, accumulating in certain areas.
Article
Green & Sustainable Science & Technology
Chongzheng Sun, Xin Fan, Yuxing Li, Hui Han, Jianlu Zhu, Liang Liu, Xiaoyi Geng
Summary: Hydrogen energy and ammonia energy have gained global attention as ideal storage media for wind and solar energy. A study found that in complex sloshing conditions at sea, the heat transfer performance in the liquid ammonia temperature zone is not affected, indicating strong adaptability for offshore operations. Therefore, accelerating the development of offshore ammonia energy industry is crucial for ensuring energy supply security.
Article
Nanoscience & Nanotechnology
A. Kosinska, B. Balakin, P. Kosinski
Summary: This study explores the conversion of solar energy to heat using different fluids, comparing the performance of coffee colloids and carbon black nanofluids. The results show that both coffee colloid and nanofluid systems have higher thermal efficiency compared to pure water, with improvements of 12% and 16% respectively. By conducting experiments and developing a mathematical model, researchers have identified the potential of a new type of fluid for solar energy applications.
Article
Mechanics
Karim Ragui, Rachid Bennacer, Mohammed El Ganaoui
Summary: This study demonstrates the oscillatory characteristics of nanofluids in free convective flow within horizontal concentric annuli, utilizing various models to generate ideal suspended particles and incorporate aggregation mechanisms. The accuracy of the numerical tool is validated through multiple tests, leading to the establishment of a new settling chart for non-settling processes in different sizes of annuli.