Ammonia has been used as a refrigerant since the initial practical use of the vapour compression refrigeration cycle was developed. It has remained the main refrigerant in
industrial refrigeration systems because of its superior thermodynamic properties and low cost. Restrictions on CFC, HCFC and many HFC refrigerants have re-focused attention on Ammonia. Performing the design or rating of a heat exchanger can be quite tedious and repetitive. Calculation steps involve complex equations, and small errors and rounding off might amplify the global tolerance of the calculation. If the process has to be iterated a few times to find an efficient and costeffective heat exchanger, it becomes quite time-consuming. But, there are heat exchanger design software that help engineers in performing the design and ratings effi ciently. Unilab Coils has introduced software that allows engineers to design and rate fi nned heat exchangers in the following calculation modalities:
• Heating and cooling of air without any change of phase of the liquid, gas or refrigerant in the tubes.
• Condensing and direct expansion of refrigerants, with a change of phase.
• Steam.
• Pump evaporators with R717.
The software comes with a library of more than one thousand fluids and refrigerants including R32, R134a, R410A, R407C, R22 and all the modern refrigerants in the
international market. It incorporates an extensible archive of the most largely used geometries in the air conditioning and refrigeration industry. The user can simulate his own
geometries, and compare the capacity and air pressure drop results between geometries. The parameters that can be customized while adding or modifying a geometry
include tube diameters, tube spacing, row spacing, tube displacement (staggered or aligned), spheroidal or integral fi ns, and corrugation factor of the tubes and the fi ns.

For more information, visit www.unilab.eu or email msd@msdtech.in