Zhileng xuebao (Jan 2021)
Effect of Spray Amount on Spray Cooling Performance of Mobile AirConditioning Condenser
Abstract
In a mobile air conditioner with a double air duct, two nozzles were installed at the lower left and lower right corners of the condenser respectively, for spray cooling. With an enthalpy difference experiment, the temperature at different state points, energy consumption and refrigerating capacity were tested with outdoor temperatures of 35 ℃/24 ℃ and indoor temperatures of 27 ℃/19 ℃ (dry bulb temperature/ wet bulb temperature), and the influence of different spray quantities from 0.55 g/s to 2.10 g/s on the performance of mobile air conditioning was analyzed. The results show that with the increase in spray quantity, the evaporating pressure was almost unchanged at 1.0 MPa, but the condensing pressure decreased from 3.45 MPa to 3.14 MPa, and the condensing temperature decreased from 55.5 ℃to 51.3 ℃. Moreover, energy consumption decreased from 1582.95 W to 1465.1 W, refrigerating capacity increased from 3090 W to 3339 W, and the EER increased from 1.95 to 2.28. The cold exergy was small and the exergy efficiency of the system was only 5.19% to 6.08% because of a small difference of only 8 ℃ between the indoor and ambient temperatures. Among the different components, the maximum exergy loss coefficient occurred in the compressor, which was 0.496, 0.472, 0.479 and 0.476, respectively, while the lowest exergy efficiency was obtained in the evaporator, which was only 24.6%–26.0% .
