Thermodynamic analysis of a gas turbine cycle combined with fuel reforming for solar thermal power generation

摘要

There is insufficient literature about solarized gas turbines that achieved high efficiency and solar share simultaneously. It is because the outlet temperature of a solar receiver is always much lower than a combustor and it is difficult to design a high-efficiency exhaust-heat recovery system except for a complicated Rankine cycle. A solar-assisted chemically recuperated gas turbine system is proposed and expected to achieve a good performance by combining with two-stage fuel-steam reforming. The first stage is a low-temperature reformer, recovering exhaust gas heat, and the second stage is a high-temperature one, absorbing concentrated solar radiation. Thermodynamic analyses and comparisons are conducted. This system is expected to have a competitive thermal efficiency of 47.7%, which is 10.6 percentage points higher than that of a solarized gas turbine system without reformers. Meanwhile, it has a solar share of 75.0%, which is 12.8 percentage points higher than that of a solarized gas turbine system with a low-temperature reformer. In the viewpoint of energy level, the two-stage fuel reforming upgrades low-level thermal energy of the turbine exhaust and solar receiver into high-level chemical energy, reducing exergy destruction. The relative upgrade of energy level is 38.2% for turbine exhaust and 17.4% for solar thermal energy. (C) 2017 Elsevier Ltd. All rights reserved.