This project aims to find correlations between various flow parameters and liquid refrigerant flow distribution within a horizontal manifold supplying two-phase R134a downward into fifteen aluminum microchannels. Liquid flow rates, system pressures, and refrigerant temperatures are recorded. Prior to this project, similar experiments were conducted using an identical manifold setup with water/a...

A capillary tube is widely used as an expansion device for small refrigeration cycles. Recently, immiscible oil is sometimes used in the refrigeration cycle to improve severe lubricating conditions and to prevent blockage of the capillary tube caused by the hydrolysis of ester oil. This paper discusses the influence of mixing of the immiscible oil with the refrigerant on the flow characteristic...

A computer model representing a two-evaporator, two-intercooler refrigerator-freezer opera ting at steady-state with nonazeotropic refrigerant mixtures (CYCLEZ) has been developed at Oak Ridge National Laboratory (ORNL). This model is being used to assess the effects of system desig n and operating parameters on the cycle performance of a refrigerator-freezer designed around the L orenzMeutzner...

CFCs have been phased out, except for essential users, and HCFCs are to be eliminated by 2020, because of their ozone depletion potential. This generates a need for the investigation of zero ozone depletion potential (ODP) refrigerants or refrigerant blends. R410A is among newer brand of refrigerant blends, with zero ODP. The biggest difference to R22 is the pressure levels generated which are ...

The condensation heat transfer characteristics of nonazeotropic mixtures R1234yf and R32 (mass fractions of 0.52:0.48 and 0.77:0.23, respectively) inside a horizontal smooth tube (inner diameter 4 mm) were experimentally studied at mass fluxes ranging from 100 to 300 kg/m s. A prediction model for the forced convective condensation heat transfer characteristics of nonazeotropic refrigerant mixt...

Due to the dependence of boiling heat transfer rate on heat flux, saturation pressure, mass flux and refrigerant quality, efforts made to increase heat transfer rate often cause further drop in refrigerant saturation pressure. In this study, entropy generation mechanisms associated with two-phase flow in smooth evaporator tube subject to constant surface heat flux are investigated. Refrigerant ...

The Cryogenic Carbon CaptureTM (CCC) process is a retrofit, post-combustion technology that desublimates CO2 in the flue gas and produces a separate liquid CO2 product. This project focuses on the energy-storing version of this process, CCC ESTM. During off-peak hours, CCC ESTM generates more refrigerant than is needed for the process, which is stored in an insulated vessel as a liquid at the l...

a refrigeration cycle is a chain of various pieces of equipment including compressors, condensers, evaporators, and expansion devices each of which takes on a particular thermodynamic process duty in the cycle that eventually results in the production of the required refrigeration. the results of optimized mixed refrigerant cycles (mrcs) in part i show that the configuration of mrc is an effect...