Improving performance of flat plate solar collector using nanofluid water/zinc oxide

In this article, the effect of using water/zinc oxide nanofluid as a working fluid on the performance of solar collector is investigated experimentally. The volumetric concentration of nanoparticles is 0.4%, and the particle size is 40 nm, and the mass flow rate of the fluid varies from 1 to 3 kg/min. For this experiment, a device has been prepared with appropriate measuring instruments whose energy source is solar radiation. The solar energy absorbed by the flat plate collector is absorbed by the nanofluid of water/zinc oxide. The nanofluid is pumped to the consumer, a heat exchanger, where it heats the water. The temperature, radiation level, flow rate, and pressure in different parts of the device were measured. The pressure drop and the heat transferred are the most important results of this experimental work. The ASHRAE standard is used to calculate efficiency. The results showed that the use of water/zinc oxide nanofluid increases the collector performance compared to water. For 1 kg/min of mass flow rate, the nanofluids have a 16% increase in efficiency compared to water. From the results, it can be concluded that the choice of optimum mass flow rate in both water and nanofluid cases increases efficiency.