Повышение эффективности охлаждения оборотной воды в испарительных охладителях с псевдоожиженным слоем

Abstract

The article describes the results from experimental investigations into the hydrodynamics of a three-phase fluidized bed. Calculation dependences of the three-phase fluidized bed height on the spraying density, which can be used for achieving more efficient cooling of circulating water in evaporative coolers, are given. The optimal conditions for stable operation and the technological parameters characterizing the water cooling process in a three-phase fluidized bed are determined. An experimental setup for carrying out full-scale experiments on evaporative cooling of circulating water in a three-phase fluidized bed is constructed, and the actual potential of the evaporative water cooling technology under real conditions is determined. It is shown that the calculated and experimental data are in good agreement with each other, and validity of the accomplished investigations has been confirmed. A mathematical model of the circulating water evaporative cooling process in a three-phase fluidized bed is proposed. Based on the numerical implementation of the proposed model, the dependences of cooled water and spent humid air temperatures at the evaporator outlet on relative humidity ф, spraying ratio ц, air velocity W, and ambient air and inlet water temperatures to and tE1 have been established. An algorithm and a program have been developed for determining the temperature of outlet water tH2 and humid air tm at the outlet of the evaporative cooler. A linear dependence of the circulating water evaporative cooler’s energy coefficient on the spraying coefficient has experimentally been established for the considered cooler type. A dependence of the evaporated moisture fraction in the considered circulating water evaporative cooler on the cooled water temperature at the cooler inlet and on the spraying coefficient is established. An evaporative air cooling method is proposed, which is embodied by using an evaporative chamber with a three-phase fluidized bed and a regenerative rotating heat exchanger.