A cool way to conserve energy

Oct 1 2012


Collaboration with Grundfos produces a pioneering seawater cooling system for Lauritzen Bulkers.

Within the past year, the Lauritzen Bulkers (LB) technical department began to develop a fleet performance catalogue, called Vessel Energy Renovation Plans (VERP), to provide fuel consumption optimisation technology for newbuildings and for the existing fleet.

One of the areas covered by the catalogue – optimisation of auxiliary consumption, things like pumps, fans, and air conditioning – has already scored a major success in the form of a system for regulating seawater cooling.

The general concept was something Søren Roschmann, responsible for LB technological development and performance monitoring, had considered at a previous job but never had a chance to pursue. “So when we started the VERP programme, I called a contact of mine at Grundfos, which is a leader in regulation and circulation systems,” he says. ”He was confident that they had the technology we needed. We started the project last October, and in March of this year began working to implement a system on a test vessel, the Durban Bulker, at a shipyard in China.”

Shipboard seawater cooling systems normally pump a given amount of water that is calculated to cool the engine and other systems in a hot, tropical climate. This means that vessels sailing in cooler climates waste a lot of energy by pumping through the same amount of water as they would in the tropics.

The basic function of the system developed for the Durban Bulker is to ensure that all operating temperature parameters of the engine and other systems are kept within certain limits. The system is designed to wind down requirements on pumps in accordance with the actual temperature of outside seawater – to pump enough water to provide sufficient cooling, but no more.

An excellent team

This is a pioneering effort, and one for which JL and Grundfos were well matched. “The technology for this kind of seawater cooling system is something we had thought about for quite a while,” says Kim Kirkegaard, business development manager for Grundfos. “We had talked with other companies about it, but JL was the only one that said, ‘OK, let’s do it.’

JL and Grundfos made an excellent team for the project. We both wanted to make it work – and thanks to great cooperation from the crew on the Durban Bulker, we did.” The result was the formation of a team comprised of JL and Grundfos technicians to work on the project. When the Durban Bulker left the Shanghai shipyard in early spring this year, the installation was not yet complete.

In May, the team joined the vessel again in Malaysia and finished the physical part of the installation. Then, during a ten-day voyage to Australia, the team set up system parameters and automation and performed functionality tests. When it came apparent after leaving Australia that further adjustments were necessary, the team came on board again in Tacoma,on the west coast of the USA, and spent ten days on board doing fine-tuning. “Since then,” says Søren Roschmann, “the system has been working very well.

The results have been impressive: we’ve been able to cut energy consumption on pumps by 35 to 50 per cent, depending on the climate where we’re sailing. This can potentially translate into one to two per cent overall fuel savings. We will continue to gather experience from operations and see if there are any final adjustments that need to be made. But so far it appears to be a great success. We have built a lot of confidence in Grundfos and the system – which I believe is the first of its kind – and are planning to install it on other vessels in the LB fleet.”

"The results have been impressive: we've been able to cut energy consumption on pumps by 35 to 50 %, depending on the climate where we're sailing." says Søren Roschmann Technical Superintendent, Lauritzen Bulkers.

Read the full article in Lauritzen News no. 17, October 2012  >>>

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