Investigation of the effect of the using latent heat storage technology in an air conditioning system on the requirement of space cooling

In this study, the thermal and economic investigation of the use of Phase Change Materials (PCM) in an air-conditioning system with a classical mechanical vapour compression refrigeration cycle was experimentally studied. For this purpose, an air-conditioning system with a latent heat energy storage unit was established in the laboratory conditions. Thus, it was aimed to reduce the space cooling costs with the method, which is called as the active system for air conditioning systems. For this, two different phase change materials with relatively high-energy storage capacities and phase transition temperatures were placed in the energy storage unit designed on the air conditioning duct using the macroencapsulation method. Aluminium metal plates with rectangular prism geometry were used for the macro-encapsulation process. In this experimental study, to examine the thermal behaviour of the latent heat energy storage unit and its effect on the cooling need, performance tests were carried out by considering different air conditions and distances between plates. The charging process of the macroencapsulated PCMs was carried out simultaneously at 1.5, 2 and 2.5 m/s air velocities (at 9°C, 11°C and 13°C air temperatures) and using return air (at 3°C, 6°C and 9°C air temperatures). Discharge processes were carried out at 1.5 – 2 – 2.5 m/s air velocities (at 38°C, 34°C and 32°C air temperatures). In addition, different distances between the plates as 10 mm and 20 mm were studied in both charge and discharge processes. As a result of the experimental studies carried out; it was determined that with the narrowing of the distances between the plates placed in the energy storage unit, there was an increase of 17-24% in the average heat transfer rates between air and PCM, and the time to reach the thermal comfort conditions was improved by 25-37%, depending on the more effective use of all plates loaded with PCM. However, as a result of the economic analysis performed, it was found that the amount of savings obtained differ in simultaneous charging and return air charging systems. In the light of the data obtained, it was concluded that it was possible to save up to 26.5% of the electricity usage cost under different conditions, by using phase change material in the air-conditioning system with the latent heat storage unit.