Thermal protection by integration of vacuum insulation panel in liquid-cooled active thermal management for electronics package exposed to thermal radiation

Thermal Management Systems (TMSs) working for electronics packages under harsh environments like intense thermal radiation is challenging due to external thermal interactions. Thermal insulation protection for TMS is very critical in these harsh conditions. An experimental set-up was developed to analyse the effect of insulation protection against thermal irradiation over a pumped liquid-cooling Active Thermal Management System (ATMS) with varying heat dissipation rate (0 - 4.2 kW/m2), thermal irradiation (0.85-3.80 kW/m2) and coolant temperature (15-25 C). Three configurations of ATMS are considered in the experimental study- ATMS without thermal insulation protection, ATMSs integrated with Cellulose Fibre Insulation (CFI) and Vacuum Insulation Panel (VIP). The effect of insulation on each parameter in all three ATMS configurations over the temperature of the electronics component, cooling load, and nature of heat flow in ATMS was analysed. VIP outperformed CFI on achieving a significant reduction in temperature of electronics systems (35.67 %) and cooling load (45.64 %) experienced by the ATMS. VIP effectively reduced the impact of temperature and cooling load change in ATMS against change in thermal irradiation. The study concluded that thermal insulation protection was most effective at high thermal irradiation and low heat dissipation rate. Heat Flow Direction Index (HFDI) concept was developed to find the nature of heat transfer direction in ATMS without temperature distribution trend. Heat generation rate and irradiation possess significant influence over the nature of heat flow direction.

VALIDATION OF EQUATIONS LECKNER FOR CALCULATE THE EMISSIVITY OF GAS COMBUSTION MIXTURE OBTAINED FROM THE COMPARATION WITH THE METHOD OF HOTTEL AND THE APPLICATION ON AN INDUSTRIAL THREE BED REGENERATIVE CHAMBER COMBUSTION UNIT

This paper investigates the validity of the LECKNER to calculate the of mixture of gas combustion in by H. and R. J. Tucker method for enclosures with surfaces exposed to significant thermal radiation. The analysis is focused on a specific combustion chamber in a three-bed regenerative oxidizer and calculates the coefficient of absorption and the corresponding thermal irradiation flux exchanges among the hot wall surfaces of the chamber. The temperature distribution and the initial composition of the gaseous mixture at the inlet plane were assumed known.

Separation of Lanthanide Isotopes from Mixed Fission Product Samples

The measurement of radioactive fission products from nuclear events has important implications for nuclear data production, environmental monitoring, and nuclear forensics. In a previous paper, the authors reported the optimization of an intra-group lanthanide separation using LN extraction resin from Eichrom Technologies®, Inc. and a nitric acid gradient. In this work, the method was demonstrated for the separation and quantification of multiple short-lived fission product lanthanide isotopes from a fission product sample produced from the thermal irradiation of highly enriched uranium. The separations were performed in parallel in quadruplicate with reproducible results and high decontamination factors for 153Sm, 156Eu, and 161Tb. Based on the results obtained here, the fission yields for 144Ce, 153Sm, 156Eu, and 161Tb are consistent with published fission yields. This work demonstrates the effectiveness of the separations for the intended application of short-lived lanthanide fission product analysis requiring high decontamination factors.

Enhancing the Fire Resistance of Concrete Structures by Applying Fire-Retardant Temperature-Resistant Metal Coatings

The issues relating to an increase in the fire-resistance of concrete structures by applying (heat dissipating) fire-retardant and fire resistant metal coatings onto them was considered. The experimental investigation data obtained for the heating rate of the brick coated with the aluminum layer as heat dissipating coating were given. The investigation was carried out through the comparison of a time-dependent change in the temperature of the material coated with the aluminum layer with the temperature of uncoated material. The obtained research results proved a decrease in the heating rate of the coated brick exposed to the thermal irradiation.

Assessment of the Thermal Radiation Regime of the Crane Operator Workplace for Making the Reasonable Choice of the Climate System of the Metallurgical Crane Cabin

The tendency of increasing of radiation sources power in metallurgy leads to an increase in the level of thermal radiation at the crane operator workplaces. The state of their health is characterized by a decrease in physical performance, the occurrence of colds, and occupational diseases of the cardiovascular and respiratory systems. Therefore, it is necessary to evaluate the thermal radiation regime of the crane operator workplace for further justification of the choice of the method and means of thermal protection. To assess the thermal irradiation of the metallurgical crane cabin, along with the method of building the thermal irradiation plot, the finite element method was used which was integrated into the automated software package ANSYS, into its plug-in Fluid Flow (Fluent) designed to build models of convective energy transfer by a liquid or gas flow. Flow turbulence is described by the Shear Stress Transport (SST) model. The article examines the thermal radiation situation in the steelmaking shop, which determines the choice of means to ensure an optimal microclimate at the crane operator workplace. It was revealed that the thermal radiation and the temperature of the railings of the metallurgical crane cabin significantly exceed the maximum permissible level, as a result of which it became impossible to choose a climate system that provides for a comfortable air temperature inside the cabin. To reduce the thermal load on the designed climate system, thermal protection elements are introduced into the design of the metallurgical crane cabin, such as a heat-reflecting screen of the floor and side wall and double glazing of the front wall. Then a high-temperature industrial air conditioner was selected, the efficiency of which was confirmed by the results of computer simulation. Thus, for a reasonable choice of the climate system of a metallurgical crane cabin, it is required to have rational combination of the methods and means of thermal protection used at the equipment design stage.

Reversible dielectric switching behavior of a 1D coordination polymer induced by photo and thermal irradiation

Switchable dielectric relaxation is achieved through photocycloaddition/reversion within a 1D coordination polymer on thermal and photo irradiation.