Safe and efficient delivery of LNG in Russia
The production of LNG with very high plant availability combined with extreme climatic influences (cold) in Russia repeatedly presents operators and plant manufacturers with major challenges. This also applies to the construction of a new LNG plant in Kaliningrad, Russia, on the Baltic coast.
The plant will process pipeline gas into LNG in close proximity to an existing compressor station, which will then be delivered to end consumers by sea and land.
Task
A Munich-based technology group was commissioned by a Russian consortium to plan and partially build this plant for the production of natural gas (LNG) on the Russian Baltic coast. The production facility has a capacity of approx. 1.5 million tonnes of LNG per year and is therefore in the mid-range of existing LNG plants worldwide (mid-scale LNG).
Thanks to a multi-stage and energy-saving process, the plant is highly efficient in the liquefaction of natural gas and can therefore fulfil special customer requirements. The customer’s requirements for high availability and a high level of safety place corresponding demands on the components used. With regard to the pumps to be used, in addition to the API requirements, unusual demands were also made for low delivery volumes combined with very high differential pressures.
Solution
True to the motto “unusual tasks require unusual solutions”, Hermetic developed a creative solution in collaboration with the customer. Based on a medium, multi-stage pump hydraulic size, two canned motor pumps in a tandem design with a U-shaped connecting pipe on a skid were planned. Each of the two vertical canned motor pumps has 10 delivery stages and delivers 50% of the required delivery head. The tandem design increases the pressure over 5 stages before the liquid flows completely through the motor into the second 5-stage impeller package, where the pressure is increased again. After the transfer through the connecting pipe to the second pump, the process is repeated and the target delivery head of 700 metres is achieved. Both pumps are controlled by frequency converters.
A special feature of the pumps that should be emphasised is the interchangeability of the pumps with each other – the two pumps work in opposite directions with regard to gravity due to the U-shaped arrangement. This means that only one of the multistage canned motor pumps is required for replacement purposes and can be installed in both positions as required.
The pumps are equipped with pressure pots to safely withstand high pressures at low temperatures and the nozzle forces defined in the project. The maximum sound pressure level of 79dBa was also adhered to or undercut – the pumps are barely audible during operation at the delivery point and are very quiet.
