Performance of parabolic trough solar collector with spinning star inserts in receiver tube with hybrid nanofluid

Abstract

To achieve better performance from parabolic solar trough collector, rotational motion in the heat-carrying liquid is imposed by installing spinning star inserts in the steady receiver. The goal of this analytical investigation is to reduce the temperature gradient in the fluid flow. A total of four cases for parabolic trough collectors are simulated in ANSYS 22R1 Fluent. Three steady receivers fitted with rotating star inserts and one without inserts is examined. Hybrid nanofluids of 1% volume content in water are obtained by mixing aluminum oxide and copper oxide. This examination considers rotating inserts in the receiver with a velocity ranging from 0 to 15 rad/s. The flow rate is from 0.016 kg/s to 0.033 kg/s. The outcomes are analyzed in terms of thermal efficiency, Nusselt number, outlet temperature, and pump work demand. It is observed that maximum improvement for thermal efficiency and Nusselt number are 38.03% and 50.90% for case 3 (star inserts with fin height of 25 mm and length of 4 mm) at 15 rad/s than receiver without inserts with nanofluid 1 (copper oxide 75%–aluminum oxide 25%) for 0.033 kg/s flow rate. At the same operating condition, the maximum increment for pump work demand is 20.41% for case 3 than receivers without inserts.