THERMAL CONVECTION ANALYSIS OF HEAT PUMP SYSTEMS

• Published in: Revista Romana de Inginerie Civila Vol. 10; no. 3; pp. 316 - 319
• Main Authors: Baran, Andreea Irina, Mateescu, Teodor Dorin Dumitru, Luciu, Razvan Silviu
• Format: Journal Article
• Language: English
• Published: Bucharest Matrix Rom 01.01.2019
• Subjects: Climate change; Cold; Consumption; Cooling; Correlation analysis; Energy consumption; Energy efficiency; Energy management; Energy shortages; Energy storage; Free convection; Geometry; Global economy; Heat exchangers; Heat pumps; Heat transfer; Heating; Heating systems; Hypotheses; Mechanical vapor compression; Nanofluids; Optimization; Phase change materials; Power efficiency; R&D; Research & development; Seasons; Self compensation; Sustainable development; Thermal energy; Thermal resources; United States > US; Chicago Illinois
• ISSN: 2068-3987; 2559-7485

Correlated with EU directives, the national energy strategy provides important measures in order to improve energy efficiency in buildings and related facilities, as well as using advanced technologies and materias and by promoting appropriate solutions and equipment in full knowledge of the peculiarities and applicability limits for different categories of requirements, with maximum functional and energy efficiency. Since it is known that in the energy balance the biggest share is in thermal energy, it is appropriate to say that continuous efforts in the optimization of conventional fuel saving solutions and intense promotion of renewable energies is highly justified. Also taking into account the major energy crisis, foreseeable for the global economy, we can say that there is a need for a series of research and development strategies in terms of energy performance, transport and storage. The use of renewable energy forms in the cooling and heating systems, as well as the „waste heat" resulted from different processes is consistent with sustainable development and helps reduce the consumption and emissions of conventional fuels. Plant systems equipped with heat pumps with mechanical vapor compression require the existence of an additional source with a low thermal potential, normally obtained from the natural environment. For example, the additional source can be arranged in line with the utilization of the residual heat from the system in self-compensating regime, when the system is designed to heat the space during the cold season and cool it during summer. In this case, the heat surplus from the cooling operation is gathered in seasonal storage and provides the necessary intake for heating, resulting the autonomy and independence of the system regardless the natural thermal resources. Replacing the usual secondary agent with nanofluids increases heat transfer by significantly increasing the convective transfer coefficient and also the storage of thermal energy in phase-change materials is a method that has experienced significant development in recent years, being attractive in terms of the large amount of thermal energy accumulated by the storage medium per unit volume at constant temperature.