Experimental study of in-line tube bundle heat transfer in vertical foam flow

Abstract

Foam has an especially large inter-phase contact surface which allows using it as a coolant. Characteristics of one type of foam -statically stable foamdemonstrated its perfect availability for this purpose. Our previous investigations of heat transfer processes in statically stable foam flow showed that large heat transfer intensity may be reached at a small mass flow rate of the foam. Statically stable foam flow is the two-phase system that has number of peculiarities: drainage of liquid from foam, diffusive gas transfer and destruction of inter-bubble films. Those phenomena are closely linked with each other and make extremely complicated an application of analytic methods for the study of heat transfer in foam. Thus experimental method of investigation was selected in our work. Experimental investigation of the heat transfer process from the in-line tube bundle to the vertical statically stable foam flow was performed. Dependency of heat transfer intensity on flow parameters and on tube position in the bundle was determined. The results of the experimental investigation are presented in this paper.

Peculiarities of heat transfer from in-line tube bundles to upward aqueous foam flow

“…This work is an extension of our previous works [7][8][9]. Heat transfer from four in-line tube bundles with different types of geometries to the vertical upward statically stable foam flow was investigated experimentally.…”

“…Investigation was performed on the experimental set-up consisting of experimental channel, foam generator, in-line tube bundle, gas and liquid flow meters, liquid storage reservoir, compressor, electric current transformer and stabilizer [7][8][9]. Cross section of the channel had dimensions (0.14 x 0.14) m 2 ; height of experimental channel was 1.8 m.…”

“…Statically stable foam (one type of aqueous foam) was used for experiments [7][8][9]. Foam-able liquid for the statically stable foam generation was produced from water solution with the detergents.…”

Experimental investigation of the heat transfer process between a tube bundle and an upward aqueous foam flow

“…The experimental equipment [7,9] consisted of the following parts: a vertical experimental channel with integrated non-standard tube bundle, gas and liquid control valves, gas and liquid flow meters, a liquid storage reservoir, a liquid level control reservoir, a compressor with a receiver, an electric current transformer and a stabilizer. The cross section of the experimental channel had the dimensions of 0.14 x 0.14 m 2 ; its height was 1.8 m. The walls of the channel were made from transparent material so that the foam flow could be observed visually.…”

“…Therefore, we performed the investigation where heat transfer between the staggered [6] and inline [7,8] tube bundles and the vertically upward (in one case) and downward (in the other case) after 180 degree turning foam flow was explored. The purpose for this is acquiring the data that could be used for designing the real heat exchanger.…”