Thermal and economic performances comparison of different pulverized coal power systems augmented by solar trough or tower technologies

Abstract

In this study, three different solar-assisted pulverized coal power (SPCP) systems utilizing solar trough or tower technologies are investigated and compared. In scheme 1, the parabolic trough solar collector is parallel to the high-pressure feed-water heaters. In scheme 2, the solar tower field is parallel to the boiler. In scheme 3, the solar tower field is connected in series between intermediate- and low-pressure cylinders. Results show that even though the same amount of solar energy is introduced into the three SPCP systems, the exergy that can be efficiently utilized differs due to the varying integrating temperature range in these three SPCP systems. The standard coal consumption rates of SPCP systems are lower when compared with the pulverized coal power system, but the levelized costs of electricity of SPCP systems are higher due to the heavy solar field investment. Among all the SPCP systems, scheme 3 owns the lowest standard coal consumption rate (275.11 g/kWh) and levelized cost of electricity (4.30 US$/kWh). Therefore, scheme 3 is recommended for the development of SPCP in the near and midterm. The economic performance of SPCP systems will improve as coal price rises or solar field cost falls when compared with the pulverized coal power system.