冷却塔实验室模型英文文献和中文翻译(4)
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Experiments were conducted with water with an initial temperature of 40-80~ In addition to temperature
measurements, standard instruments controlled the humidity of the air surrounding the facility, the speed of the
external wind flow, and the vertical velocity of the vapor-air mixture flow ascending above the model.
For each fixed temperature of the water supplied for cooling, we changed the conditions of the flow of the
external wind stream around the model. At a temperature of the supplied water of 60~ experiments were carded
out additionally with periodic supply of warm water to the water distributor.
For the most part, experiments were conducted for two positions of the lower rotating plates: the angle 90 ~
corresponds to completely open windows (the conditions of operation of an actual cooling tower) and the angle 45 ~
corresponds to the mode with flow swirling. Some of the experiments were carried out with two-sided symmetric
swirling of the flow with respect to the external wind.
Each set of experiments was performed in the following way. Heated water of prescribed temperature was
pumped through the water distributor. After the attainment of quasisteady conditions with respect to the principal
controlled parameters (temperature and volumetric flow rate of the entering water), the surrounding air humidity
and the ascending flow velocity were recorded, the measuring system was actuated, and data was collected with
subsequent statistical processing.
Results of the Investigations. From the results of visual observations we can draw the following conclusions.
Under conventional conditions (when S << 1) unstable vortices with a characteristic dimension on the order of 0.1D
are formed spontaneously in the conelike portion of the tower. The process of the formation and existence of
separate vortices terminates near the mouth of the tower. Against the background of the general circulation of the
vapor-air mixture the above effect was not observed in the mode of swirling of the incoming flow. As the wind speed
increases (the parameter S >> 1), a large-scale vortical flow originates in the conventional mode in the lower part
of the tower model above the water distributor (stagnant zone) with a characteristic dimension of about 2/3 of the
height of the tower. Flow swirling (even at a strong wind S = 2) eliminates the formation of stagnant zones that
affect the thermal operating efficiency of the tower negatively.
In what follows, we present quantitative results obtained on the laboratory setup at one temperature mode
of the entering water (T O = 60~ This mode makes it possible to create a rather intense ascending vapor-air flow
in the laboratory model with a large concentration of droplets, which improves the visualization of the structures
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