Low flow rate spray cooling by a flow blurring injector

摘要

Spray cooling characteristics of a flow blurring injector are investigated experimentally. Variations of the flow rates and the distance from the nozzle to the test surface are examined in terms of the cooling heat flux. The liquid flow rate is varied from 200 to 1200 mL/h. The effect of the air flow rate from 6 to 18 L/min is also studied and heat transfer coefficients are obtained. Depending on different effective parameters, the maximum cooling heat flux is measured between 61 and 193 W/cm~2. Owing to formation of fine droplets at higher air flow rates, the maximum cooling heat flux is improved by about 60%. The present data is generated for a flow blurring type of injector to have four major advantages simultaneously compared to the previous twin-fluid injectors. These advantages can be listed as; having fine droplets using low liquid flow rates, low liquid and gas pressures, relatively large orifice diameters, and a simple design. Here, with the mentioned privileges, it is demonstrated that the same maximum range of heat flux is achieved by about one order of magnitude less liquid consumption rate than previous studies.