Air conditioning contributes significantly to building energy consumption in hot climate regions. In addition to greater cooling requirements in hot climates, cooling equipment efficiency decreases with increasing outdoor temperature. Therefore, it is advantageous to develop improved technologies that can achieve higher efficiency at high ambient conditions. In this paper, two novel compression...

In this paper the results of both modeling and testing a representative 3-ton air-to-air heat pump running with the baseline refrigerant (HCFC-22) and zero ODP alternative refrigerants will be presented. Alternative refrigerant simulation runs are made with two pure fluids (HFC-134a and HFC-152a) and an azeotropicmixture (60/40wt%) ofHFC-32 and HFC125 (Allied-Signal Inc. U.S. Patent 4,978,467)....

A self-consistent density-functional approach is presented for describing the phase behaviour and interfacial tensions of van der Waals fluids represented by the hard-core Yukawa (HCY), Lennard-Jones (LJ) and square-well (SW) potentials. The excess Helmholtz energy functional is formulated in terms of a modified fundamental measure theory (MFMT) for the shortranged repulsion and a density-gradi...

the presence of particles in liquid-solid fluidized beds enhances the bed heat transfer, because the movement of the particles leads to an increased turbulence in the system. moreover, the violent movement of the particles has a positive effect on fouling of the heat transfer surface. the aim of this investigation was to perform systematic measurements of bed voidage and heat transfer coefficie...

the present study aimed at estimating the amount of carbon storage and its relationship with other physical and chemical soil properties in four land-use systems including intact, protected, exploited and garden-uses areas in the northern zagros region in west azarbaijan province, iran. thirty sample plots were identified and within each plot, soil samples were taken in each land use and each s...

In a PEMFC, feeding dry hydrogen into a dead-ended anode (DEA), reduces the overall system cost, weight and volume due to reduced need for a hydrogen-grade humidification and recirculation subsystems, but requires purging to remove the accumulated water and inert gas. Although the DEA method of operation might be undesirable due to its associated high spatial variability it provides a unique pe...

Two-phase ejectors are devices capable of improving the performance of refrigeration and air conditioning cycles by means of expansion work recovery. Ejector studies often focus on the design and performance of the two-phase ejector and the effect it can have on the performance of the ejector cycle. However, the ejector is not the only component of the system that can have a significant influen...