Application and Research Progress of Heat Pipe in Thermal Management of Lithium-Ion Battery

Lithium-ion batteries have the advantages of high energy density, high average output voltage, long service life, and environmental protection, and are widely used in the power system of new energy vehicles. However, during the working process of the battery, the working temperature is too high or too low, which will affect the charging and discharging performance, battery capacity and battery safety. As a result, a battery thermal management system (BTMS) is essential to maintain the proper ambient temperature of the working battery. Thermal management of power batteries is a key technology to ensure maximum battery safety and efficiency. This paper discusses the significance of thermal management technology in the development of new energy vehicles, introduces the main technical means of thermal management of lithium-ion batteries for vehicle, and focuses on the current state of research on the use of various types of heat pipes in lithium-ion batteries. Finally, the use of heat pipes in the thermal control of lithium-ion batteries is promising.Citation: Ning, Y., Tao, R., Luo, J., and Hu, Q. (2022). Application and Research Progress of Heat Pipe in Thermal Management of Lithium-Ion Battery. Trends in Renewable Energy, 8, 130-144. DOI: 10.17737/tre.2022.8.2.0014

The Effects of Salt on Rheological Properties of Asphalt after Long-Term Aging

Limited studies in recent years have shown that asphalt pavement subject to seawater in coastal regions or deicing salt in cold regions may be seriously damaged after being soaked in saline water for a long time. However, there is limited research into the influence of salt on rheological properties of asphalt after long-term aging. In this study, rheological properties of unmodified and polymer-modified asphalt after long-term aging were tested after being soaked in different concentrations of salt (0.3%~5%) for different durations (1 day~30 days). Orthogonal array based on the Taguchi method was used for experimental design. The frequency sweep tests were performed on the specimens of aged asphalt after being soaked for complex modulus and phase angle master curves and ultimate fatigue temperature. BBR tests were performed for stiffness. The test results indicate that saline water appears to reduce low temperature properties and fatigue resistance properties and improved high temperature properties of aged asphalt, and it also affects the sensitivity of complex modulus and phase angles at low frequencies

Fault Diagnosis of Supervision and Homogenization Distance Based on Local Linear Embedding Algorithm

In view of the problems of uneven distribution of reality fault samples and dimension reduction effect of locally linear embedding (LLE) algorithm which is easily affected by neighboring points, an improved local linear embedding algorithm of homogenization distance (HLLE) is developed. The method makes the overall distribution of sample points tend to be homogenization and reduces the influence of neighboring points using homogenization distance instead of the traditional Euclidean distance. It is helpful to choose effective neighboring points to construct weight matrix for dimension reduction. Because the fault recognition performance improvement of HLLE is limited and unstable, the paper further proposes a new local linear embedding algorithm of supervision and homogenization distance (SHLLE) by adding the supervised learning mechanism. On the basis of homogenization distance, supervised learning increases the category information of sample points so that the same category of sample points will be gathered and the heterogeneous category of sample points will be scattered. It effectively improves the performance of fault diagnosis and maintains stability at the same time. A comparison of the methods mentioned above was made by simulation experiment with rotor system fault diagnosis, and the results show that SHLLE algorithm has superior fault recognition performance

A review on catalytic methane combustion at low temperatures:Catalysts, mechanisms, reaction conditions and reactor designs

International audienceNatural gas (with methane as its main component) provides an attractive energy source because of its large abundance and its high heat of combustion per mole of carbon dioxide generated. However, the emissions released from the conventional flame combustion (essentially NO x) have harmful impacts on the environment and the human health. Within the scope of rational and clean use of fossil energies, the catalytic combustion of natural gas appears as one of the most promising alternatives to flammable combustion. The presence of catalysts enables complete oxidation of methane at much lower temperatures (typically 500 � C), so that the formation of pollutants can be largely avoided. This work presents a literature review on the catalytic methane combustion. Various aspects are discussed including the catalyst types, the reaction mechanisms and kinetic characteristics, effects of various influencing operational factors and different reactor types proposed and tested. This paper may serve as an essential reference that contributes to the development of well-designed reactors, equipped with appropriate catalysts, and under well-handled operating conditions to realize the favorable (kinetic) performance, for their future applications and propagation in different industrial sectors