Quasi-local absorption heat transfer coefficients and pressure drop inside a horizontal tube absorber have been investigated experimentally, with R-22/DMA as the working pair. The absorber is a counterflow coaxial tube-in-tube heat-exchanger with the working fluid flowing in the inner tube while the water moves through the annulus. A large temperature gliding has been experienced during the absorption process. Experimental results show that the heat transfer coefficient of the forced convective vapor absorption process is higher compared to the vertical falling film absorption. A qualitative study is made to analyze the effect of mass flux, vapor quality and solution concentration on pressure drop and heat transfer coefficients. On the basis of the experimental results, a new correlation is proposed whereby the two-phase heat transfer is taken as a product of the forced convection of the absorption and the combined effect of heat and mass transfer at the interface. The correlation is found to predict the experimental data almost within 30 percent.

Issue Section:
Technical Notes
Keywords:
Experimental, Forced Convection, Heat Transfer, Heat Pump, forced convection, pipe flow, heat pumps, pressure, mass transfer, heat transfer, two-phase flow
Topics:
Absorption, Compression, Forced convection, Heat pumps, Heat transfer, Heat transfer coefficients, Water, Mass transfer, Vapors, Pressure drop, Temperature, Circuits
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