Experimental Study
The experimental setup to be used in this study consists of a specially designed and built water tank and measuring systems. The main tank, which is also used in other studies and measures 1 m x 1 m x 1 m, is made of chrome-plated panels against corrosion, and there is an observation window made of 10 mm thick glass on the front of the tank. (Fig.1.) Thanks to this window, the progress of the experiments and some measurement results can be observed.
The indicator on the left of the experimental setup shows the water temperatures measured at 5,15,30,50,70,90 cm distances from the bottom after the stratification of the water body. (Fig.2.)
In order to minimize the heat exchange with the external environment, the outer circumference of the water tank is covered with insulating material. A cooling system is integrated in the lower part of the tank in order to create the stratification caused by the heat effect in the lake and dam reservoirs. The cooling system consists of compressor, condenser, filter, capillary tube, copper pipes, thermostat and monitor. A 20-meter-long copper pipe, connected to the system and connected to the thermostat-controlled cooling system, through which cold gas passes, is laid under the tank in a spiral shape. The design of the cooling system is shown in Figure.3.
a b
Fig.3. (a) The cooling system used in the experiments. (b) Layout of copper pipes and air diffuser and temperature gauges in the water tank.
Strip heaters are placed on top of the tank to heat the top layers as desired. The experimental setup used in this study is unique in that it achieves lifelike stratification between the stratified layers with the strip heaters placed at the top and the copper pipe placed at the bottom to heat the water in the tank. In experiments where mixing is planned with an air diffuser, an air diffuser specially designed for this study will be used. A total of 20 replaceable plates with d=1,2,3,4, and 5 mm diameters with single hole, double hole, five holes and twelve holes have been designed and made compatible with the diffuser to be used in the preliminary experiments. In the first place, the air required for the diffusers will be supplied by air pumps that provide Q=100l/h, 200l/h and 400l/h flow rates (Tetra-Tec Aps 400). As a result of these experiments, the most suitable dimensionless parameter for mixing efficiency will be determined.
