Thermodynamic analysis and heat exchanger calculations of transcritical high-temperature heat pumps

Heating in industrial processes is responsible for approximately 13% of greenhouse gas emissions in Europe. Switching from fossil-fuel based boilers to heat pumps can help mitigate the effect of global warming. The present work proposes novel high-temperature transcritical heat pump cycles targeted at heating air with a mass flow rate of 10...

Motility of Chlamydomonas reinhardtii at different temperatures: The universe in a droplet

Algae remains a focal point of scientific inquiry with its wide-ranging environmental, health, and energy applications. Among model organisms, the unicellular green alga Chlamydomonas reinhardtii holds significance, particularly in light of its responsiveness to temperature alterations impacting swimming velocity. Notably, this study...

Monolithic fiber/foam-structured catalysts: beyond honeycombs and micro-channels

Heterogeneous catalysis plays a pivotal role in the current chemical and energy vectors production. Notably, to fully utilize the intrinsic activity and selectivity of a catalyst, the chemical reactor has to be designed and operated optimally to achieve enhanced heat/mass transfer, well-defined contact time of reactants, uniform flow pattern,...

A macro prediction model for butt-welded (U)HSS connections with softened HAZ

This paper reports an investigation on the tensile resistance of fully-penetrated butt-welded connections of (ultra-)high-strength steels considering the strength softening of the heat-affected zone (HAZ) and the strengthening due to the transverse constraint. Firstly, a parametric study is carried out to analyse the tensile behaviour of...

Discharge performance of a high temperature phase change material with low-cost wire mesh

Thermal energy storage is increasingly needed in a sustainable world because of its potential of capturing waste heat and being incorporated in solar power plants. For power generation, in particular, as turbine technology advances, a demand for higher temperature thermal energy storage materials also grows. For this purpose, latent thermal...

Mapping knowledge domains for mine heat hazard: a bibliometric analysis of research trends and future needs

As the shallow mineral resources are nearly depleted, the mining of deep resources has become an urgent problem to be studied. The increase in mine depth can lead to the increase of mine heat hazard, which is a critical concern for mining safety/occupational health and safety. However, there are limited review articles available regarding the...

A designed wall roughness approach to improve turbulent heat transfer to supercritical CO₂ flowing in horizontal tubes

Supercritical flow through a horizontal pipe leads to a non-uniform peripheral wall temperature distribution even when the wall heat flux is kept constant and uniform. This is attributed to lower heat transfer coefficient at the top section where the denser fluid tends to sink. Hence, to obtain a uniform wall temperature, a designed wall...

Parametrization of aerodynamic and canopy resistances for modeling evapotranspiration of greenhouse cucumber

Estimating the latent heat flux accurately is important to improve greenhouse crops irrigation schedules. Aerodynamic and canopy resistances, as two key parameters in the Bulk transfer equations, are already difficult to measure in the open field and even more in greenhouses. In this study, an experiment was conducted in a Venlo-type cucumber...

Numerical analysis of heating rate effect on spalling of high-performance concrete under high temperature conditions

High-performance concrete (HPC) is vulnerable to spalling under high temperature conditions and it has been found that the heating rate can exert a tremendous effect on spalling of HPC. To prevent HPC from spalling, the heating rate effect should be understood. However, quantitative analyses are still lacking and the heating rate effect has...