Experimental investigation of air conditioning system using evaporative cooling condenser

Tianwei Wang, Purdue University

Abstract

This study presents an experimental investigation of the Coefficient of Performance (COP) augmentation of an air conditioning system utilizing an evaporative cooling condenser. The experimental facility consisted of four major components: compressor, evaporator, thermal expansion valve, and condenser. An evaporative cooling unit was located upstream from the condenser. Thermal parameters, such as relative humidity, dry bulb temperature, and wet bulb temperature were measured to evaluate the effect of in-direct evaporative cooling on the system COP. The results indicated an inverse relation between the condenser inlet dry bulb temperature and the COP. The changes in specific enthalpy of the air across the evaporative cooled condenser were due to latent heat transfer and sensible heat exchanges, whereas the specific enthalpy changes for the conventional condenser were primarily caused by sensible heat exchanges. By using the evaporative cooling condenser to pre-cool the air, the saturation temperature drop through the condenser increased from 2.4°C to 6.6°C. It also resulted in an increase of the mass flow rate of refrigerant into the evaporator; this mass increase of liquid entering the evaporator consequently resulted in the increase of COP from 6.1% to 18%. A power reduction up to 14.3% on the compressor was also achieved. Under partial load conditions, the DEC system showed a 20% less COP reduction compared to the conventional system. The result revealed the relation between water consumption and compressor energy saving. Although greater power reductions were fulfilled at higher dry bulb temperatures, the optimal applicable temperature was around 33.1°C.

Degree

M.S.E.

Advisors

Nnanna, Purdue University.

Subject Area

Mechanical engineering

COinS