Enhancement options for separate sensible and latent cooling air-conditioning systems

The performance of desiccant wheel (DW)-assisted separate sensible and latent cooling (SSLC) air-conditioning systems has been greatly improved by the application of divided heat exchangers, resulting in 7% and 46% increases in COP for R410A and CO2 systems, respectively. The paper simulated new performance-enhancing options that include evaporative cooling, a sensible wheel (SW) and an enthalpy wheel (EW) to the SSLC systems. The application of evaporative cooling to the SSLC system further improves the system COP by 7% and 14% respectively. By applying an EW to the SSLC systems, the COP is improved by 39% and 40% respectively. The DW-assisted SSLC technology also can be adopted for the dedicated outdoor system (DOS). It is concluded that only the EW is effective for enhancing the DW-assisted SSLC DOS systems because it lowers not only the cooling requirement of the vapor compression cycle, but also the heat requirement for DW regeneration.

► Divided heat exchangers improve SSLC system COP by reducing the discharge pressure.
► The evaporative cooling process benefits more to the CO2 SSLC system than R410A.
► The CO2 enthalpy wheel-desiccant assisted SSLC system achieves a high COP of 5.9.
► Sensible wheel is not suitable for the SSLC-DOS system.