Pumps & Geothermal

Sulzer provides an example of the connection between old & new technologies

As the International Energy Forum projects that global geothermal capacity must increase by 3.6 GW annually throughout the 2020s to align with the Paris Agreement, tapping into this largely underutilized renewable energy source has become crucial. Sulzer is supporting the transition to clean power by providing its proven range of VS6 pumps, designed to support new and existing Organic Rankine Cycle (ORC) plants, as well as world-class rotating equipment services.

Compared to traditional thermal power generation, ORC plants operate at much lower temperatures around 105°C to 185°C. Rather than using steam to drive a turbine, a secondary organic fluid with a lower boiling point is heated by the geothermal fluid via a heat exchanger. The organic fluid expands into a gas and powers a turbine and generator, producing renewable energy. Following this, it is condensed and reheated as part of a closed loop.

Sulzer has built a reputation as a premier supplier of hydrocarbon feed pumps for ORC geothermal applications. Its VS6 pumps are adept at circulating the condensed organic fluid within the closed loop process and are being specified for geothermal projects globally.

Sergio Periz, Tendering Manager at Sulzer Pumps Spain, explains the challenges: “While the organic fluid in ORC processes is noncorrosive, its lower boiling point and higher vapor pressure mean that the fluid is constantly trying to escape the pump. Fortunately, Sulzer has the pump technologies and expertise to overcome these unique challenges so the VS6 mechanical sealing system is highly specialized.

“ORC plant project lead times are typically short - usually less than two years – so we may have only a month or less to prepare our tender. Our response times are critical, as are the lead times for the pumps, despite the highly technical nature of these projects.”