LAUSR

Abstract The paper presents the results of the numerical investigation of the thermal stratification occurring in the three-coil heat exchanger creating the hot water storage tank. The heat exchanger considered is a special type of coiled tube exchanger which can recover the waste heat from air conditioning system. The exchanger consists of three finned tube coils which are immersed in the storage tank of hot water. Two coils - lower and upper – are designed to warm water in the tank using water as a heating medium. The third coil – equipped with special buffer layer with the nanofluid - uses the refrigerant for the waste heat transfer. The temperature stratification device is mounted in the thermal storage tank. The device’s application is to improve the thermal stratification level of heated water. The performed numerical simulations allowed to obtain the temperature and velocity fields in the storage tank under conditions of the work of coils filled with water. Calculations were made regarding the use of the stratification device under the operating of the upper and lower coils with water conditions.