Automotive fixed orifice tube (FOT) systems are especially prone to cycling losses due to their clutch cycling operation. Therefore, it is important to better understand the dynamics of the refrigerant and oil migration during transient events such as cycling and start-up . To measure the refrigerant mass and oil distribution of an automotive R134a FOT breadboard system, two ball valves around ...

The primary goal of work described in this paper is to evaluate and enhance a virtual refrigerant charge sensor, developed in a previous study. The virtual refrigerant charge sensor algorithm employs low-cost and non-invasive measurements (i.e. surface mounted temperature measurements) to estimate refrigerant charge level for packaged air conditioning systems. It can be embedded within a portab...

In this study, three new mixed refrigerants with low GWP values, R1234yf/R134a, R1234yf/R125, and R1234yf/R13I1, were evaluated as replacements for R134a refrigerant using two vapor compression configurations. The experiment revealed that these mixtures can be used environmentally friendly alternatives configuration.

Since long time, it has been noticed that refrigerators are the devices which work almost 365 days round the clock; hence objective of energy efficiency improvement attracts much. There are several ways of improving the performance of a vapor compression refrigeration cycle. Use of an ejector as expansion device is one of the alternative way. The advent of new component ‘Ejector’ into refrigera...

This paper presents the improvement of eco-friendly and power consumption saving refrigerants for refrigeration systems. The novel azeotropic refrigerant mixtures HFCs HCs can replace systems, using R134, R32, R125, R1270 in several compositions found decision tree function RapidMiner software (which came first KDnuggets annual poll). All results are mixed POE, which is A1 classification refrig...

An experimental study of a pilot scale passive solar hot ~ater heating system utilizing a boiling collector is presented. The self-pumping system alternates between two modes of operation. During the run . cycle, vapor pressure drives the evaporated refr1gerant downward from the collector to the condenser. Once a preset quantity of refrigerant is condensed, vapor pressure is again used to force...

A variety of hydrofluorocarbon (HFC) compounds, both as pure substances and mixtures, are being developed as alternative refrigerants to replace the exsting chlorofluorocarbons and hydrofluorocarbons which have been linked to stratospheric ozone depletion. The use ofHFC's in refrigeration systems will require new lubricants, and polyolesters are being widely promoted as the lubricant of choice ...

Oil return from the evaporator to the compressor suction port is an important requirement. It is affected by the refrigerant/lubricant properties, gas velocities and piping geometry. The refrigerant R -134a has successfully replaced R-12 in household refrigerators and freezers. This paper describes a test method to estimate the mean oil film thickness and to observe the flow pattern in vertical...

This research studies the influence of using SiO2 nano-particles 50nm in a Vapor Compression Refrigeration System (VCRS), along with Poly-alkylene Glycol (PAG) oil and R-134a mixed to create nano-refrigerant. The methodology used this work, were performed three different concentrations (0.1%, 0.3%, 0.5%) 200ml PAG oil. A VCR system was built at mechanical engineering department laboratory Al-Qa...