Güntner: Adiabatic gas coolers ‘boost CO₂ transcritical efficiency’

“Adiabatic gas coolers help to promote CO₂ transcritical in warm ambient climates” of up to as much as 40°C by reducing the power consumption of these systems, Till Beyer of Güntner, a German heat exchanger manufacturer, told R744.com at last year’s Sifa tradeshow.

Beyer was speaking at the Salon Interprofessionel du Froid et de ses Applications (Sifa) tradeshow in Lyon, France (28-29 November), where he was presenting the firm’s technology offer to the French market.

Adiabatic coolers are designed to improve the efficiency of the CO₂ refrigeration cycle by combining two physical principles: the sub-cooling of the refrigerant and the adiabatic cooling of the air.

Understanding adiabatic cooling

In thermodynamics, an adiabatic process is one that occurs without transfer of heat between a thermodynamic system and its surroundings. The system is thus 'adiabatically isolated'. Adiabatic cooling occurs when pressure on the adiabatically isolated system is decreased, allowing it to expand and causing it to do work on its surroundings.

The gas coolers employ a fan system to draw ambient air through the adiabatic area. In the adiabatic section, the air temperature decreases thanks to the adiabatic cooling effect.

Beyer expressed optimism about the growth prospects for CO₂ -based refrigeration systems in France, citing the variety of technology options already available (such as condensing units) and the potential for CO₂ to make greater inroads into smaller HVAC&R applications such as cold storage in bakeries or butchers.