Current Advances in Ejector Modeling, Experimentation and Applications for Refrigeration and Heat Pumps. Part 1: Single-Phase Ejectors

Analysis and Comparison of Two-Phase Ejector Performance Metrics for R134a and CO2 Ejectors

Two-phase ejectors have been gaining increased attention in recent years due to their ability to directly improve the COP of the cycle. Of common interest in two-phase ejector studies is how the ejector improves cycle COP. However, less emphasis is often given to the performance of the two-phase ejector itself. The amount of COP improvement offered by an ejector cycle is very strongly influence...

Two-phase flow in high-heat-flux micro-channel heat sink for refrigeration cooling applications: Part II—heat transfer characteristics

This paper is the second of a two-part study concerning two-phase flow and heat transfer characteristics of R134a in a micro-channel heat sink incorporated as an evaporator in a refrigeration cycle. Boiling heat transfer coefficients were measured by controlling heat flux (q00 = 15.9 93.8W/cm) and vapor quality (xe = 0.26 0.87) over a broad range of mass velocity. While prior studies point to e...

Exergy Flows inside a One Phase Ejector for Refrigeration Systems

Abstract: The evaluation of the thermodynamic performance of the mutual transformation of different kinds of exergy linked to the intensive thermodynamic parameters of the flow inside the ejector of a refrigeration system is undertaken. Two thermodynamic metrics, exergy produced and exergy consumed, are introduced to assess these transformations. Their calculation is based on the evaluation of ...

Advances in Research and Applications of Smart Hydrogels Part I: Preparation Methods and Classification

Two-phase flow in high-heat-flux micro-channel heat sink for refrigeration cooling applications: Part I––pressure drop characteristics

Two-phase pressure drop was measured across a micro-channel heat sink that served as an evaporator in a refrigeration cycle. The micro-channels were formed by machining 231lm wide · 713lm deep grooves into the surface of a copper block. Experiments were performed with refrigerant R134a that spanned the following conditions: inlet pressure of Pin = 1.44–6.60bar, mass velocity of G = 127–654kg/m ...