EXPERIMENTAL STUDIES OF THE AIR HEAT EXCHANGER OF THE SIDE-EVAPORATION TYPE

Over the past two decades, many new devices based on renewable energy have been introduced for heating purposes: new heat recovery units, heat pumps, solar systems and many others However, no devices based on renewable energy sources have been widely applied in the field of cooling until now. This poses an important scientific challenge for researchers worldwide. A new solution that can solve the above-mentioned problems is direct and indirect air cooling through evaporation. Evaporative air coolers use the cooled heat of water evaporation to provide cooling and are less dependent on fossil fuels, they also feature a significantly higher conversion factor compared to mechanical compression systems. A higher transformation coefficient shows that the considered devices are able to reduce a significant part of the energy consumption used for air conditioning. One of the best methods for achieving very low temperatures with indirect evaporative air cooling is a new thermodynamic cycle known as the Maysotsenko cycle (M-cycle). Air heat exchangers of the indirect-evaporative type based on the Maisotsenko cycle have a higher transformation coefficient, so it is advisable to use them for cooling livestock premises. The creation of workable and cost-effective designs of air heat exchangers (heat utilizers) for livestock premises, which can be aggregated with a set of ventilation equipment, is a complex scientific and engineering task. According to the results of experimental studies of the indirect-evaporative type laboratory heat exchanger, the dependences of the temperature of the output primary air flow, the coefficient of thermal efficiency and effective cooling capacity on the temperature of the primary air flow at the inlet, its absolute humidity and its flow rate were obtained. Analyzing the obtained dependencies, it is possible to draw a conclusion about the correspondence between the results of numerical modeling and experimental studies, which is confirmed by the high value of the Pearson correlation coefficient (0.92–0.94). The optimal values of the factors under the condition of maximizing the effective cooling capacity NE = 426 W (different areas of the holes), NE = 380 W (the same areas of the holes) are tin = 32 °С, xin = 5 g/kg, Qin = 169 m3/h.