NUMERICAL STUDY OF A SINGLE STAGE VAPOR COMPRESSION REFRIGERANT UNIT USING NON-CONTAMINANT REFRIGERANTS

摘要

A numerical simulation of the thermal and fluid-dynamic behaviour of a single stage vapor compression refrigerant unit has been developed and improved. The modelization consists of a main program that calls sequentially different subroutines until the convergence is reached. These subroutines modelize the physical flow phenomena produced inside a double-pipe condenser and evaporator, a capillary tube expansion device, a reciprocating compressor and the different connecting tubes between these four main elements. The software makes the analysis possible in transient or steady state of a wide range of situations, taking into account different working fluids, geometries and boundary conditions. All the flow variables (temperature, pressure, mass vapor fraction, void fraction, velocity, heat flux, etc…) are evaluated at each point of the grid in which the domain is discretized. An experimental unit has been designed and built to analyze single stage vapor compression refrigerating equipment. The objective of this experimental unit is to validate the numerical simulation of each component and the equipment as a whole. In addition to this validation, some illustrative results are shown using non-contaminant refrigerants.