Direct steam generation using evacuated tube collector with nanoparticles: experimental study

At costly expense used to produce steam through the use of optical concentration. The study's scalable, affordably priced solar steam generating system is built upon an evacuated tube collector. The manifold consists of an evacuated outer tube that collects and transfers solar radiation, and an inner tube that supplies cold water from the storage tank using forced circulation mode. The outer tube produces 16 kg of steam over a 10-h period of operation, with an average solar irradiance of 919.5 W. During the period, the evacuated tube attained an average temperature of 94 to 110 °C and its corresponding module heat exchanger temperature of the range was 87 to 100 °C, resulting in a 79.4% increase in thermal efficiency and a steam pressure of 1 bar with the corresponding actual and expected heat output of water was 2406 and 3027.2 kcal respectively. When the supply of cold water was immersed in CuO, Al₂O₃, and ZnO nanoparticles, the efficiency improved to 82, 81, and 80.5%, with corresponding practical heat outputs of 2486, 2454, 2438 and actual heat outputs of 3027.2 kcal, respectively. These steam-generating devices have more potential for improvement in the scope of solar thermal applications.