Energy and exergy analysis of flat plate solar collector for three working fluids, under the same conditions

Abstract

The growth and expansion of the population, has caused increased the use of energy in the last few years. One of the cleanest and renewable sources of the energy is the solar energy. The solar energy can be collected by solar collectors. One of the solar collectors is the flat plate solar collector (FPC), that it is used in domestic utilization. Use of various Nano-fluids to improve the thermal properties of solar collectors, considered as one of the most effective method to optimize the flat plate collectors. In this study, a FPC in terms of energy and exergy, for three fluids (water, air and TiO2 Nano-fluid) have been investigated. According to the results obtained and under the same conditions, destruction exergy of water is more than other two fluids and TiO2 Nano-fluid has the least amount of destruction exergy. Also, by increasing in the total radiation on tilted surface (Gt) TiO2 Nano-fluid’s exergy efficiency is more than the other fluids in this study. By increasing ambient temperature, the exergy efficiency decreases, that water has the most variation. Due to the temperature range of the inlet working fluid to the collector’s tubes, observed that outlet temperature of the TiO2 Nano-fluid is about 50°C higher than when water enters it. Therefore, the initial statement about Nano-fluids is confirmed. In appropriate conditions, the collector’s efficiency is between 45% - 50%, thus FPC is one of the best devices for domestic utilization.