Performance Evaluation of an Indirect Evaporative Cooler.

摘要

The performance of an indirect evaporative cooler operating to pre-cool mixed air in a variable-air-volume (VAV) system typical of a small office building is experimentally verified in a carefully controlled laboratory environment that realistically simulates performance in a field application. The data collected are correlated and applied using the bin methodology described in Chapter 36 of the 1984 ASHRAE Systems Handbook to calculate energy savings and peak electric demand reduction of the indirect evaporative cooler configuration compared to conventional vapor-compression refrigeration. Results of these calculations for Dallas, Texas, show annual operating savings of 9% in electrical energy for cooling and a slight reduction in peak electric power demand. The Seasonal Energy Efficiency (SEER) for the indirect evaporative cooler is 70% higher than that of the back-up high-efficiency air conditioner, and nearly 12% of the conventional air conditioning capacity is displaced by the evaporative cooler. Surprisingly, the use of a constant Lewis number to relate heat and mass transfer in certain analytical models of indirect evaporative coolers is not supported by the experimental data acquired.