Ultra Pure Water Cooling System for High Voltage DC (HVDC) System

GRE have been designing and manufacturing ultra-pure water systems for many years.

We were approached by an international market-leading manufacturer of HVDC thyristor valves to build a cooling system for a demonstration system at their global headquarters. This system is used for (a) research and development on the new generation of valves and (b) as a showcase for customers. The valves themselves are used for converting electricity from AC to DC and vice-versa, and is ultimately used to provide power for the whole of society. Because of the extremely high voltages present within the valves – often several 100,000’s of volts – the water must not contain ANY impurities that could conduct electricity. Pure water itself is actually a good electrical insulator, and the system must maintain the conductivity of the water at less than 0.5 μS/cm – which equates to a resistance through the fluid of 2Mega Ohms. This extremely high level of resistance makes the system safe when high voltages are introduced.


Key features:

  • A run and standby pump set
  • Deionisation system to maintain water purity
  • Constant measurement and control of water conductivity, with alarm indication if required parameters are not met
  • Accounts for system expansion and removed gasses (O2 and H) produced by electrolysis.
  • Fully packaged and skid-mounted for simple installation

This high-profile installation was completed in December 2014 and has operated without issue since.