A study of solar steam accumulator with high temperature latent heat thermal energy storage (2nd report, fundamental characteristics of steam accumulator)

摘要

In the present paper, we will propose high-temperature latent heat thermal energy storage (LHTES) system for the steam accumulator. Most of conventional LHTES systems employed phase change material (PCM) with relatively low melting point. The principal purpose of the past LHTES system was applications to space heating/cooling. In the companion paper (1st report). the charging and discharging characteristics of the high melting point phase change materials were revealed experimentally. However, since fossil fuels like petroleum. coal, and natural gas will sooner or later run out in the 21st century, natural energies like solar. wind, and biomass will rise as one of alternative energy sources. One of the most promising means to produce power from these natural energies is the solar Rankine cycle system which operates under a low temperature range below 200°C. Solar heat is collected and stored as pressurized hot water in the LHTES accumulator in daytime, and the steam turbines or various type of expanders will be operated whenever energy demand exists. As an application of the LHTES system to steam accumulator is taken up and the possible thermal performance of this accumulator will be discussed theoretically. Further, this article describes the designing of the high-temperature LHTES steam accumulator, and clarifies the charging characteristics by the experiment The present LHTES system is applied to solar Rankine cycle system will be introduced.