Simulation of hybrid two‐tank storage concentrated solar plant using supercritical carbon dioxide in TRNSYS

Abstract

AbstractTo meet heating demand without global warming is a huge target for the energy community these days. To attain this challenge, solar energy harvesting to meet domestic hot water demand is a promising solution. Carbon dioxide (CO2) is becoming ever more significant as heat transporting fluid. Simulation‐based efficiency assessment models are requisite for analogous advances. This research presents a dynamic simulation model of high temperature concentrated solar plant using directly heated molten salt to indirectly power a supercritical CO2 Brayton cycle. Target of the study is to achieve 1 MW generation and simulation work is performed in TRNSYS computer software. The operating conditions for the plant cycle and efficiency for indirectly heated CO2 recompression Brayton cycle are also calculated with the help of engineering equation solver. The system is divided into three major loops: solar thermal heat collection, power generation, and heat recovery. Results have shown overall cycle efficiency up to 40%. During the day hours from 4688 to 4697, receiver provides a constant outlet temperature of 700°C with a fluid inlet flow rate of 15 kg/s and mediating fluid after exchanging heat enters the receiver's end at 524°C. An optimized value of 2.9 is selected as pressure ratio to meet supercritical conditions at the compressor inlet. Output power generated is 3.035 MW with turbine efficiency is 92%. The power calculated for main compressor and recompressor are 0.68 and 0.228 MW, respectively.