Geothermal utilization is a mature and proven technology, providing base-load power onto the grid with capacity factors as high as 90%.
Geothermal power plants are reliable, sustainable and non-polluting. In the past, geothermal plants were most often located at the edges of tectonic plates where high-temperature water was available near the surface. More recently, new technologies have allowed plants to be located closer to population centers, drilling deeper into the earth to find sources of thermal energy. These plants can however be challenging endeavors with steam temperatures exceeding 300°C (570°F).
From dry steam to flashed steam to binary-cycle geothermal applications, Flowserve provides a wide array of special process pumps such as high temperature verticals and circulators along with high-temperature mechanical seals, isolation and control valves as well as our unsurpassed materials expertise to address the most challenging applications and corrosion issues.
The Binary-cycle plant, also known as an engineered geothermal system (EGS), operates at the lowest temperatures of any geothermal plant, typically from about 107°C to 182°C (225°F to 360°F). These plants use heat from the geothermal water to boil a working fluid, usually an organic compound with a lower boiling point (e.g. isopentane). The working fluid is vaporized in a heat exchanger and the vapor turns a turbine/generator. The water is then injected back into the ground to be reheated. The water and the working fluid are confined in separate closed loops during the process, so there are little or no air emissions.
Flashed-steam is the most common type of geothermal power plant. This type of plant taps in to reservoirs of water with temperature greater than 182°C (360°F). The very hot water flows up through wells under its own pressure. As it flows to the surface, the fluid pressure decreases and some of the hot water boils or “flashes” into steam. The steam is then separated from the water and used to power a turbine/generator unit. The remaining water and condensed steam are injected through a well back into the reservoir.