This work analyses and compares two approaches to evaluate the boiling heat transfer of CO2 in a real evaporation process: classical empirical correlations and flow pattern maps. We develop a finite-volume mathematical ...
[EN] This work presents a mathematical model of a shell-and-tube evaporator based on mass continuity, energy conservation and heat transfer physical fundamentals. The model is formulated as a control volume combination ...
[EN] This work presents a mathematical model of a shell-and-tube condenser based on mass continuity, energy conservation and heat transfer
physical fundamentals, whose methodology can be easily adapted for modelling any ...
The aim of the present paper is to describe a general methodology suitable for analysing any intermediate configuration considered in staged vapour compression refrigeration cycles. This general methodology only depends ...
[EN] In this paper, a simplified model for the study of shell-and-tubes heat exchangers (HXs) is proposed. The model aims to agree with the HXs when they are working as condensers or evaporators. Despite its simplicity, ...
[EN] Based on a previously developed and validated steady-state model of a single-stage vapour compression plant, the present paper describes an in-depth study directed to examine the consequences of changes in the operating ...
[EN] This work presents an experimental evaluation, from an energy analysis point of view, for two of the most used inter-stage systems in two-stage vapour compression cycles driven by compound compressors: the direct ...
The gas-cooler heat exchanger is a characteristic device of the refrigeration plants that use CO2 as the working fluid in transcritical conditions. The proper gas-cooler sizing, allows getting the maximum effectiveness in ...
[EN] The performance of an Internal Heat Exchanger (IHX) operating in a CO 2 transcritical refrigeration plant is analysed, from an energetic point of view, in this work. The evaluation is based on experimental data by ...
This work focuses on the investigation of new drop-in or long-term refrigerants for low evaporating
temperatures that can be used as substitutes for HCFC-22, which is gradually being phased-out. This
process is already ...
[EN] The EU Regulation 517/2014 has recently been approved in a further attempt to curb the
effects of GlobalWarming. As a consequence, the refrigeration sector is moving towards refrigerants
with a low GlobalWarming ...
[EN] This paper presents a detailed experimental analysis of the energetic effects of using a subcooler system in a two-stage refrigeration facility driven by a compound compressor. The analysis is carried out by comparing ...
The Regulation CE-1005/2009 has banned the use of virgin HCFC-22 in Europe from the 31st December 2009, because it contains chlorine, although its use is allowed up to the 31st December 2014 if it is recycled. Now, ...
[EN] This work presents the experimental evaluation of the energy efficiency and optimal gas-cooler pressures of a single-stage refrigerating plant working with carbon dioxide as refrigerant in transcritical conditions. ...
The paper presents the analysis of the energy performance of an air vortex cooling tube under variations of the
air inlet properties, with three independent experimental tests validated through the energy balance in the ...
[EN] The aim of the present paper is to detail an analysis, based on experimental data, of the inter-stage working conditions of a two-stage vapour compression facility equipped with a compound compressor, which operates ...
[EN] The world community has committed to eliminate the HCFC-22 refrigerant to a series of deadlines according to the agreements taken during the 19th Montreal Protocol meeting in September 2007. This phase-out, which is ...
[EN] This work evaluates, from an energetic point of view. the effects of the superheat caused in the refrigerant by the electric motor cooling (SHsc) in a semihermetic compressor installed in an experimental refrigerating ...
[ES] El objetivo delt rabajo es presentar una revisión de las máquinas frigoríficas tritérmicas de adsorción, con mención especial en las que trabajan con la mezcla silicagel (o gel de sílice)-agua. La estructura seguida ...
[EN] This work presents a procedure for calculating the COP and heat transfer rates, based on on-site experimental temperature measurements, of a lithium¿bromide/water direct-fired double-effect absorption chiller in reverse ...