Heat exchangers
Refrigerators and freezers typically use single-tube heat exchangers where the refrigerant, in a two-phase state, offers high heat transfer efficiency on the refrigerant side, while fins or wires and fans enhance heat transfer on the air side. Studies highlight inefficiencies due to uneven refrigerant distribution, leading to unused heat exchanger sections and reduced energy efficiency, particularly in condensers and evaporators. Noise reduction in fan and heat exchanger systems has been extensively studied in automotive, heating, ventilation and air conditioning applications, but domestic appliances lack comprehensive data, necessitating further research on adapting these techniques. Acoustic optimization and efficient heat exchanger designs are crucial for improving performance and customer satisfaction.
The project aims to develop a precision test bench for objective evaluation of heat exchangers, replicating real installation conditions on the air side and optimal operating conditions on the refrigerant side. This setup allows detailed analysis of heat exchanger efficiency influenced by factors like flow direction, pressure drop, air mass flow, and environmental conditions.
A second goal is to improve fan and airflow acoustics, enabling higher air mass flow without increasing noise, using experimental and computational methods. The precision test bench will ensure repeatable measurements and facilitate the creation of heat exchanger maps for optimizing designs.
