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...

Two multiple-tracer tests were conducted at The Geysers to evaluate the relative properties of various gas tracers with respect to tritiated water. In this study the geographic distribution of the tracer responses in the two tests are compared. The DV-11 test, which was conducted in 1994, used the chlorofluorocarbon R-13 and SF6. The P-1 test used the newly developed hydrofluorocarbon tracers R...

The methods for improving second law efficiency have been considered in this paper by using liquid vapour heat exchanger is investigated in this paper. Detailed energy and exergy analysis of multi-evaporators at different temperatures with single compressor and single expansion valve using liquid vapour heat exchanger vapour compression refrigeration systems have been done in terms of performan...

The ability of zeotropic mixtures with a temperature glide to operate in liquid recirculation systems is investigated in this paper, and the preliminary results of an experimental comparison between the performance of R134a and of zeotropic mixture R32/Rl34a, (25/75 by mass) are presented. The perfonnance of Rl34a operating in dry expansion mode are also presented as baseline data. INTRODUCTION...

The proper addition of additives to pure CO2 can improve the performance as a working fluid. By fluid, we mean fluid used for CO2-based transcritical power cycle characterized by R134a CO2. Hence, an experimental investigation pressure drop characteristics supercritical CO2/R134a mixture in rectangular microchannel was conducted. For this purpose, accurate and stable thermal-hydraulic system de...

An experimental performance study on VCR system with 100g R600a/R290 refrigerant mixture and 100g R600a (pure isobutene) as drop in replacement of R134a was conducted . continuation running tests were performed under different length of capillary for R600a/R290 & R600a. The result showed that the hydrocarbon mixture (R600a/R290) had highest COP at L=10 feet length capillary by17.35% -23.5% for ...