The technology group Wärtsilä has successfully installed its Serck Como Horizontal Tube Evaporator (HiTE) fresh water production system on board the pipe-laying vessel, Lorelay, owned by offshore contractor Allseas. This is the first commercial installation of this Wärtsilä innovation. The retrofit project produces clean water for technical applications and human consumption and has led to fuel savings of as much as one tonne per day.
The unique aspect of the Wärtsilä HiTE is that it is a multi-stage evaporator specifically designed for small to medium capacities of 30 to 150 tonnes per day. Previously, significant design compromises were needed in order to handle such capacities. The Wärtsilä HiTE is designed to function in a wide range of operational areas, i.e. shallow waters with poor quality seawater, where alternative technologies, such as reverse osmosis or plate technology, reach their limits. The operation of the Wärtsilä HiTE achieves energy savings of 75% compared to single-stage designs with a specific heat consumption of 200 to 280 kWh per tonne, depending on design.
“This evaporator produces pure distillate, even in difficult seawater conditions, plus it does so reliably and with low operating costs. The possibility to operate the unit at part load gives it great flexibility to utilise available waste heat. Our engineering team has confirmed that the Wärtsilä HiTE is exceeding our expectations, and that it is completely in line with the technical specifications and the requested maximum allowed energy consumption. The system produces good quality water, and we are extremely happy with the outcome,” explains Taco Straathof, Technical Inspector, Allseas.
The unit’s control system is fully automatic. Furthermore, the HiTE has the flexibility to operate while the engines are at low load during dynamic positioning (DP) operations. For example, at DP the Lorelayoperates at engine loads of between 15% and 35%. The system’s automated smart processes adjust according to the amount of energy provided, which is an important factor for vessels with varying engine profiles.
The Wärtsilä HiTE is suited for a variety of vessel types, including special vessels, chemical tankers, small cruise ships, and for offshore applications.