Fluid flow distribution optimization for minimizing the peak temperature of a tubular solar receiver

Abstract

High temperature solar receiver is a core component of solar thermal power plants. However, non-uniform solar irradiation on the receiver walls and flow maldistribution of heat transfer fluid inside the tubes may cause the excessive peak temperature, consequently leading to the reduced lifetime. This paper presents an original CFD-based evolutionary algorithm to determine the optimal fluid distribution in a tubular solar receiver for the minimization of its peak temperature. A pressurized-air solar receiver comprising of 45 parallel tubes subjected to a Gaussian-shape net heat flux absorbed by the receiver is used for study. Two optimality criteria are used for the algorithm: identical outlet fluid temperatures and identical temperatures on the centerline of the heated surface. The influences of different filling materials and thermal contact resistances on the optimal fluid distribution and on the peak temperature reduction are also evaluated and discussed.Results show that the fluid distribution optimization using the algorithm could minimize the peak temperature of the receiver under the optimality criterion of identical temperatures on the centerline. Different shapes of optimal fluid distribution are determined for various filling materials. Cheap material with low thermal conductivity can also meet the peak temperature threshold through optimizing the fluid distribution.

Single-tank thermal energy storage systems for concentrated solar power: Flow distribution optimization for thermocline evolution management

“…Their numerical results indicated that compared to uniform velocity profile, certain non-uniform flow profiles could lead to the reduced thermocline thickness and smaller entropy generation. This is actually in line with some observations reported in the literature [Kumar and Singh, 2019;Milman et al, 2012;Wei et al, 2015a] in that the optimal flow distribution is usually not uniform but obeys certain trend subjected to a defined optimization objective and constraints. However, controversy still exists on the relation between the optimal velocity profile and the expected thermocline evolution.…”

Experimental measurement of flow distribution in a parallel mini‐channel fluidic network using PIV technique

“…Once the reliable technique has been established for the precise measurement of flow distribution, the next task is how to control the flow distribution properties so as to improve the global performances of tubular process equipment or energy conversion systems. In some cases, a uniform distribution among parallel channels is generally required, while in many other cases, a target flow distribution which is non‐uniform should be achieved . In our earlier work, an original CFD‐based evolutionary algorithm has been proposed to realize uniform or non‐uniform fluid flow distribution among parallel channels .…”

Residence time distribution on flow characterisation of multichannel systems: Modelling and experimentation

“…However, industrial applications usually require large production rate which in general means high throughput, a weak point for most micro-or mini-devices. Numbering-up process [3][4][5][6][7][8] is then applied, in the form of 2D or 3D multichannel/layer systems or modular reconfigurable devices. Particularly for multichannel systems, the parallelisation of a large number of flow/mixing/reaction paths helps achieve industrial-level production.…”