Institutional Repository of GuangZhou Institute of Energy Conversion, CAS
Not a member yet
23976 research outputs found
Sort by
Performance analysis of zeotropic organic Rankine cycle with a vapor-liquid injector
No full textTo improve the performance of small-scale organic Rankine cycle (ORC), an ORC with a vaporliquid injector (IORC) using zeotropic mixture R601a/R245fa as working fluid is proposed. Parametrical investigations of the injector and system are carried out. The research results of injector show pure R601a has the highest injector pressure lift and exergy efficiency. The working fluids with higher temperature glide tend to have lower exergy efficiency. The increase of injector entrainment ratio and injector area ratio decreases pressure lift and exergy efficiency. The research results of system shows that the introduction of the zeotropic working fluid and injector can complement advantages and disadvantages of each other. Taking R601a/R245fa (60 %:40 %) as working fluid, IORC has higher net power than basic ORC (BORC) when pump efficiency is lower than 88 % and hot water temperature drop is less than 51 degrees C. There exists an injector entrainment ratio which makes net power maximum. Increasing injector area ratio decreases net power. Increasing injector entrainment ratio and decreasing injector area ratio reduce cooling water. Increasing injector entrainment ratio and injector area ratio makes heat exchanger economy worse
Key Laboratory of Gas Hydrate, Guangzhou Institute of Energy Conversion, Chinese Academy of Sciences[E229kf19]
No full textThe Applications and Challenges of Nanofluids as Coolants in Data Centers: A Review
No full textWith the rapid development of artificial intelligence, cloud computing and other technologies, data centers have become vital facilities. In the construction and operation of data centers, how to effectively solve the problem of cooling and energy saving is the key problem. In this review article, a critical review of recent research regarding the application of nanofluids in data center cooling are put forward. Many different aspects of nanofluids such as the classification of nanoparticles, base fluid components, and types and structures of heat exchangers were discussed. Furthermore, some advanced and up-to-date apparatus and theoretical models of utilizing nanofluids as coolants in data centers are reviewed and described in detail. Lastly, but not least, potential research directions in the future and the challenges faced by the researchers and industry in this field are proposed and discussed. In conclusion, nanofluids used as novel heat exchange medium, which has been widely proven in other areas, can also conspicuously improve data center cooling technology in the future
Valorization of Lignocellulose with One-Step Acidified Monophasic Phenoxyethanol Fractionation
No full textEffective fractionation of lignocelluosic biomass and subsequent valorization of all three major components under mild conditions were achieved. Pretreatment with acidified monophasic phenoxyethanol (EPH) efficiently removed 92.6 % lignin and 80 % xylan from poplar at 110 degrees C in 60 min, yielding high-value EPH-xyloside, EPH-modified lignin (EPHL), and a solid residue nearly purely composed of carbohydrates. After removing the grafted acetyl groups using 1 % NaOH at 50 degrees C, the highest enzymatic digestibility reached 92.3 %. EPHL could be recovered in high yield and purity with an uncondensed structure, while xylose was converted to EPH-xyloside, a potential precursor in biomedical industries. Additionally, the acidified monophasic EPH solvent could effectively fractionate biomass from species other than hardwood, achieving over 70 % delignification from recalcitrant pinewood under the same mild conditions, demonstrating the high potential of monophasic EPH pretreatment.
This work introduces an acidified monophasic phenoxyethanol (EPH) system with effective fractionation of lignocelluosic biomass under mild conditions. The pretreatment resulted in a cellulose rich residue with high enzymatic digestibility, EPH-modified lignin, and EPH-xyloside. imag
The 2023 Innovation-Driven Development Special Foundation of Guangxi Province[AA23023021]
No full text
Numerical analysis of dynamic behaviors of underwater towed system with hydrofoil manipulations
No full textThis paper addresses the dynamic characteristics of an underwater towed system under manipulations of synchronous hydrofoils, considering the coupling of instantaneous fluid forces on the complete systems and hydrofoil control, which is usually difficult to solve with existing methods. A hydrodynamic model coupled with hydrofoil control algorithms is presented, wherein the hydrodynamic forces on the hydrofoils and Underwater Towed Vehicle (UTV) are simulated using the Computational Fluid Dynamics (CFD) method, and the fluid forces on the Towing Cable (TC) are described using a flexible cable dynamic model. The dynamic behaviors of the underwater towed system under depth-undulating, depth-tracking, and depth-keeping controls of hydrofoils are analyzed using the proposed model. The results show that the towing speed has a significant effect on the control efficiency of the hydrofoils. The dynamic responses of the underwater towed system increase or decrease more significantly in submerged depth control operations than in freely towing operations. The hydrofoils can achieve satisfactory effects in submerged depth control for the UTV at an appropriate towing speed, whereas it fails at a lower towing speed and noticeable dynamic response oscillations occur simultaneously. This study is expected to provide guidance on both hydrodynamic and control issues of underwater towed systems
Exploring Porous Flow Behavior of the Decomposed Gas from CH<sub>4</sub> Hydrate in Clayey Sediments by Molecular Dynamics Simulation
No full textA fundamental understanding of the fluid flow mechanism during CH4 hydrate dissociation in nanoscale clayey sediments from the molecular perspective can provide invaluable information for macroscale natural gas hydrate (NGH) exploration. In this work, the fluid flow behaviors of the decomposed gas from CH4 hydrate within clayey nanopores under different temperature conditions are revealed by molecular dynamics (MD) simulation. The simulation results indicate that the key influencing factors of gas-water flow in nanoscale clayey sediments include the diffusion and the random migration of gas molecules. The influencing mechanisms of fluid flow in nanopores are closely related with the temperature conditions. Under a low temperature condition, the gas diffusion process is impeded by the secondary hydrate formation, leading to the decline in gas transport velocity within nanopores. However, it is still noteworthy that the gas-water fluid flow channels are not completely blocked by the occurrence of secondary hydrate. Under a high temperature condition, the significant phenomenon of water migration during gas flow is observed, which can be ascribed to the gas-liquid entrainment effect in nanopores of the clayey sediment. These results may provide valuable implications and fundamental evidence for improving gas production efficiency in future field tests of NGH exploitation in marine sediments
Access Repository Dashboard
Do you manage Institutional Repository of GuangZhou Institute of Energy Conversion, CAS? Access insider analytics, issue reports and manage access to outputs from your repository in the CORE Repository Dashboard!