Name: S u s a n W. S t e w a r t Brief Description: The HCFC refrigerant, R-22, is the most widely used residential air-conditioner refrigerant in the U.S. However, it is scheduled to be banned in new equipment beginning in 2010 due to its high ozone depletion potential (ODP). A new refrigerant, R-410A has zero ODP and favorable performance characteristics such as good cycle efficiency, non-fla...

In the case of multi-component condensation the ‘condensing vapour contains a mixture of components having different boiling points, which condense over a wide temperature range, either in presence of or absence of non-condensing material. In this work, a design algorithm for the condensation of a multi-component vapour mixture in shell side of a shell and tube vertical condenser has been devel...

A theoretical study is conducted to explore the effect of different parameters on the performance of a Loop Heat Pipe (LHP). These parameters are evaporator temperature, condenser temperature, total mass charge, the tube size of piping system, and pumping distance between evaporator and condenser. This paper pres ents a steady state model that describes the thermodynamics, heat transfer, and fl...

Accurate and optimum usage of energy sources is gaining importance all over the world due to the increase of energy need and limited energy sources. Optimum usage of energy sources is not only necessity for energy conversion systems, but also design and production of energy conversion devices. Therefore optimization of condensers is very important for HVAC systems which require as possible as m...

A heat pump system requires proper refrigerant charge amount. Once refrigerant is charged into a heat pump system, its charge amount is fixed. For this reason, prediction of optimal refrigerant charge amount is very important in order to yield best performance. Too low charge amount degrades capacity of heat pump. On the other hand, excessive charge amount decreases coefficient of performance (...

Preliminary note This paper presents the exergy destruction of an evaporator or a condenser or evaporator and condenser. The exergy destruction can be analytically calculated by using the same non-dimensional variables which have been used by its energy analysis. The one additional variable is the ratio of absolute input temperatures of both streams. This means that the given model enables the ...

Thermodynamics of an ionic-liquid (IL) based absorption refrigeration system has been numerically analyzed. It provides an alternative to the normally toxic working fluids, such as the ammonia in conventional absorption systems. The use of ILs also eliminates crystallization and metal-compatibility problems of the water/LiBr system. Mixtures of refrigerants and imidazolium-based ILs are theoret...

This study developed a magnetic-nanofluid (MNF) heat pipe (MNFHP) with magnetically enhanced thermal properties. Its main characteristic was additional porous iron nozzle in the evaporator and the condenser to form a unique flowing pattern of MNF slug and vapor, and to magnetically shield the magnet attraction on MNF flowing. The results showed that an optimal thermal conductivity exists in the...