A novel thermal storage integrated evacuated tube heat pipe solar air heater: Energy, exergy, economic and environmental impact analysis

Abstract

This study aims to present a novel thermal energy storage integrated evacuated tube heat pipe solar air heater suitable for high-temperature applications. A new heat pipe arrangement was introduced in this study by attaching all the evaporator tubes of heat pipes to a common condenser section. A thermal energy storage medium was kept in a chamber within the common condenser unit of the heat pipe to obtain uniform outlet air temperature from the system when there is fluctuation in solar radiation. Therminol 55 was used as the sensible heat storage medium in the system. The Performance evaluation of the system was conducted by varying four airflow rates 0.03 kg/s, 0.1 kg/s, 0.2 kg/s and 0.3 kg/s, respectively. 0.03 kg/s resulted in a maximum outlet air temperature of 128 °C and the system delivered more than 100 °C of hot air until 10 h of operation. The maximum thermal and exergy efficiency obtained during each airflow rate was 38%, 77%, 85%, 89%, and 5.01%, 5.21%, 5.34%, and 5.76% respectively. An average of 6200 kJ energy was collected by the present system during its operation. The total money saved per month during the operation of TS-ETHPSD was 445 INR. The Payback Period for the system is 69 months. The solar air heater can be considered as an environment-friendly device as it can save 73 kg/month of Co2 from entering the atmosphere.