Synergetic Effect of Non-Condensable Gas and Steam Quality on the Production Capacity of Geothermal Wells and Geothermal Power Generation for Hot Dry Rock

Abstract

This paper aims to fill the research gap on the effect of steam quality and non-condensable gas on heat-carrying fluid productivity, system performance and optimization. First, the effect of the temperature and quality of the heat-carrying fluid and non-condensable gas (NCG) content on the production parameters was evaluated. After that, three energy conversion systems which included a single flash (SF) system, an organic Rankine cycle (ORC) system and a single flash combined ORC (SFORC) system were constructed in this paper to utilize the heat-carrying two-phase flow with non-condensable gas. Finally, based on thermodynamic modeling, the effects of the temperature and quality of the heat-carrying fluid and non-condensable gas content on the performance and optimization of the three power conversion systems were investigated. The results show that single-phase heat-carrying fluids are more productive than two-phase heat-carrying fluids. NCG is always detrimental. The heat-carrying fluid temperature and quality are positively correlated with system efficiency and negatively correlated with the net power output. In the comparison of comprehensive performances, the SFORC system is the better, and the ORC system and the SF system are the worse. The optimal net power output of the SF system, the ORC system and the SFORC system is 4883 kW, 6557 kW and 7251 kW, respectively.