Generation of E × B flow shear by finite orbit width effects from heat sources in tokamaks

We present a possible mechanism for the generation of strong E × B flow shear relevant to internal transport barrier formation in tokamak plasmas. From gyrokinetic calculations, we show that strong E × B flow shear can be generated by finite orbit width (FOW) effects associated with a non-uniform heat source and is sufficient to lead to transport barrier formation in the core region with a moderate power level. Two FOW effects inducing neoclassical polarization are shown to be responsible for this: 1) the radial drift of particle orbit center due to the variation of the heat source within orbit width and 2) the non-uniformly evolved orbit width by the non-uniform heating.

Design and Analysis of the Location of Cold and Heat Sources for the Payload’s Active Thermal Control System on the Lunar Surface

The payload of the Chang’e-4 biological experiment is used as an object for designing and analyzing the location of cold and heat sources. The research compares and analyzes the energy consumption and temperature uniformity of cooling and heating sources mounted on different surfaces using Thermal Desktop/Sinda Fluint, which may be used to guide the design and operation of active thermal control systems. The results indicate that when the hot and cold sources are mounted on the payload’s top surface, the total energy consumption of the active thermal control system is minimized and temperature uniformity is improved.

Analysis of a Low-Speed Drive System Using Intelligent Materials

This paper presents a low speed drive system with a simple and reliable construction, which can be used in an area where there is no power supply (isolated areas, forests, agricultural fields, etc.) and which operates on the basis of two heat sources, one from solar radiation and one provided by water. Alternatively, this system can be used to recover energy from wastewater from industry. The operation and role of the parameters that can influence the value of the rotation speed of the drive system are analyzed through a simulation, maintaining a constant speed in the case of the prototype is achieved through the control system because in real situations the temperature of heat sources can vary within certain limits. The models and tests performed highlight the parameters of the analyzed drive system and the limits of the range in which its speed can vary.

A Methodology for the Identification and Characterization of Low-Temperature Waste Heat Sources and Sinks in Industrial Processes: Application in the Italian Dairy Sector

Waste heat recovery is considered as one of the most promising options to improve the efficiency and sustainability of industrial processes. Even though industrial waste heat is abundantly available and its utilization is not a new concept, the implementation rate of waste-heat recovery interventions in industrial facilities is still low, due to several real or perceived barriers. Foremost challenges are represented by technical, economic, financial and regulatory factors. An additional prominent barrier lies in the lack or incompleteness of information concerning the material and energy flows within the factories, and the types and characteristics of waste heat sources and possible sinks for their internal or external reuse. With the aim to overcome some of the information barriers and increase the willingness of companies to approach waste heat recovery and reuse, a methodology to map waste heat sources and sinks in industrial processes is proposed in this study. The approach here presented combines information from the most relevant publications on the subject and data gathered from the analysis of energy audits carried out by large and energy-intensive enterprises. In order to demonstrate its feasibility, the methodology was applied to the Italian dairy sector, because of its large energy consumption and its enormous potential for the utilization of low-temperature waste heat sources.