Geothermal Power Plant Design for Steam with High Noncondensable Gas

Abstract

Test data from some geothermal resources indicate that the fluid flowing from the wells has an exceptionally high fraction of noncondensable gas. Those data show that the well head fluid may contain 20 to 25 percent by weight of noncondensable gas. If this fluid were used in a conventional geothermal power plant, a very large performance degradation would occur, compared to the more usual geothermal fluid that contains far less noncondensable gas. This paper examines the magnitude of the performance degradation that would occur in a conventional geothermal power plant operating with steam having very high noncondensable gas. The performance of geothermal power plants with four other promising types of energy conversion processes and the equipment needed for each are described and compared to the conventional power plant. The practicability of these alternative processes is also addressed.