HEAT TRANSFER STUDY OF DIRECT CONTACT CONDENSATION IN THE PRESENCE OF NONCONDENSABLE GAS

摘要

Direct Contact Condensation tests have been conducted by injecting a mixture of steam and nitrogen into a subcooled water pool in a stainless steel tank through a vertical nozzle. The condensation rate, related to the heat transfer rate in the liquid side, was obtained by the difference of the gas inlet flow rates and the mass accumulation due to the bubble growth. By the measurements of steam and nitrogen flow rates and visualization of the bubble size variation, the heat transfer parameters in the liquid domain during the bubble formation, are obtained. The Nusselt number has been correlated with the dimensionless combination of fluid flow, system state and thermal properties of fluids. A least square approach has been applied to determine the exponent coefficients of dimensionless numbers in the correlations. It was found that the Nusselt number can be correlated by a function of the Jakob number, gas Peclet number, noncondensable concentration, liquid and gas density ratio and Eotvos number based on the current database.