Abstract:
he type of equipment comprising a geothermal power station main cooling water system can have a significant influence on the cooling water chemistry, sulphur deposition and micro- and macro-biological control in addition to the reservoir steam chemistry. A holistic approach is best when investigating problems to better understand the system and how best to implement solutions. Poihipi Road Power Station is the only geothermal steam turbine power station in New Zealand to have a shell-and-tube (surface) condenser, which has a significant influence on the cooling water chemistry compared to a direct-contact condenser. Prolific algae growth on the cooling tower also resulted in fouling throughout the cooling system and required frequent mechanical removal which increased the risk of dispersing into the air any Legionella bacteria that may have been present with the algae.
This paper provides an overview of the investigation approach performed to better understand the issues with the cooling water system and how best to address them.
