Simulation of the Performance of a High Temperature Solar Thermal Receiver Comprised Parallel Micro-Pin Unit-Cells Fabricated via Additive Manufacturing

This paper aims to assess the receiver efficiency, maximum surface temperature, and pressure drop through a ~10 MW thermal solar receiver designed to heat carbon dioxide from 550 to 720°C at 20 MPa. The solar receiver is comprised of 400 identical unit-cells fabricated using additive manufacturing. Each unit-cell contains an array of micro-pins with a single inlet and outlet for carbon dioxide. A unit-cell thermal hydraulic sub-model developed in prior work is integrated into a multiple unit-cell receiver model, which solves for the mass flow rate, outlet temperature, maximum surface temperature, efficiency, pressure drop, and other parameters of each unit-cell and the overall receiver for a specified solar flux distribution. Simulations are conducted for a scenario in which the overall outlet temperature is fixed, and the pressure drop through each parallel unit cell is the same. The results suggest that overall receiver efficiency for the parallel unit-cell approach can be optimized using different unit-cell geometries throughout the receiver.