Shore power cooling article published in Electric & Hybrid Marine Technology International Magazine in April 2022.

 

 

Shore power cooling

Shore supply delivers power to a vessel with its own AC grid on board. To ensure the power conversion from 50 Hz to 60 Hz, synchronization with the ship’s grid and eliminate harmonic disturbance, inverters are used. Shore power systems may be in the MW range, therefore the cooling of the system becomes a problem that needs to be considered. One viable option is to use water as a cooling medium.

The cooling of the shore power inverter doesn’t differ from the cooling of the inverter on-board the vessel. Thus, the inverter cooling solutions for marine onboard application may be used in the shore power inverter applications.

Shore power application may not be critical ones, and the cooling solution can be built using a single pump. For a critical application, a redundant solution with two pumps can be used.

Standard water cooling system with water-to-air heat exchanger installed for shore power supply

Technical water consideration

When using a water-cooling solution, the technical water (or cold water) issue must be solved. In practice, technical water cools the warm/hot water coming from the heat source/inverter. The cooling takes place in the heat exchanger and this applies to Shore power applications as well.

There are three ways to solve the technical water issue. The first involves cooling it with an air coole. In this solution external technical water source is not needed. The air coolers may be large, and if more cooling power is needed, a larger unit can be used. The space issue may be solved by installing the air cooler on top of the shore power assembly, for example in a container. With air coolers, noise is a key consideration. If a quieter operation is required, the air cooler solution will be more costly.

Secondly, lake or sea water can be used as the cold water source. For this solution, the water is fed directly to a water-to-water heat exchanger. The water quality needs to be considered when choosing the heat exchanger and filtration method. A stainlesssteel or titanium heat exchanger could be used for corrosion resistance. This is the same for all piping and metal parts dealing with technical cold water. Depending on the impurities of the water,  a filtration system might also be needed.

Lastly, cooling may be undertaken with cold water available at the location. Typically, this uses a chiller unit close to the site which feeds cold water to the secondary side of the heat exchanger.

 

Adwatec’s centralized system is capable of serving several shore power supply units with adequate cooling

Standard cooling modules

A water-to-water heat exchanger also features on one of the company’s standard cooling stations

 

Adwatec’s water cooling solutions were originally devised for use in tough marine conditions. What works on board a vessel also works onshore. There are no rough seas onshore, but salty and humid conditions still exist. Therefore, marine water cooling solutions are still applicable.

Standard modular construction is the same as with all Adwatec products. The solution is factory tested, produced in high volume and marine field proven.

In marine applications, the cooling system ratings top out at approximately 500 l/min (flow) and 200kW (cooling power). For shore power solutions, the options are far greater. Adwatec’s water cooling offering for electrical power grid applications extends to 10,000 l/min and 10MW. Thus, there is a water cooling option for the largest shore power need available.

 

 

 

 

WORDS:

Heikki Mustonen, Managing Director, Adwatec Oy
+358 50 477 8685
heikki.mustonen@adwatec.com