Investigation of Liquid Overfeed and DX Refrigeration Systems Performance (OR-16-018)

This paper investigates the performance of liquid overfeed and DX refrigeration systems and includes components performance and system balance. This project includes the design of two refrigeration circuits, liquid overfeed flooded and DX with a common condenser, and analyzes the performance of the heat exchangers and their impact on the overall circuit’s performance. Several design techniques and methods are considered, including geometry and construction of heat exchangers. The performance of the two circuits is compared for four operating temperatures: -20°C (-4°F), -10°C (14°F), 0°C (32°F) and 5°C (4°F) and analyzed to ascertain circuits operation. DX evaporators are often utilized operating at -10°C (14°F) and below for relatively small duty systems, below 25kW (7.1 TR). However, liquid overfeed flooded evaporators’ are rarely seen practically for systems in this range. The performance of the DX and liquid overfeed flooded evaporators’ is also analyzed for small duties at the four operating conditions.