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A Novel Water Glycol Cooling System for our Explorer Yacht

Updated: Apr 27

We have a water-glycol cooling system issue with the build of our Explorer Yacht, Vanguard. We have implemented cutting-edge hybrid diesel-electric propulsion technology to achieve a litany of advantages over what has traditionally been possible.

Water Glycol Cooling System Model for our Explorer Yacht
Water Glycol Cooling System Schema

However, there is a downside. In this instance, we need to install a Water/Glycol cooling system as described in an earlier blog. This will need both storage tanks and a method of heat dissipation. What we would like to avoid is an additional duplicated sea water calling system in the engine room with attendant leak and failure potential. A passive cooling arrangement would be much more reliable. We are fortunate that our yard, Naval Yachts, is keen to work through these issues and develop a robust solution.


Water Glycol Cooling System Installation: The Problem

Water Glycol Cooling System Installation
Water Glycol Cooling System Installation

We need to install water/glycol storage tanks low down in the hull form. Not to be confused with the water/glycol cooling system used on the diesel engines. These shall remain as stand-alone systems.


The new tanks will hold the cooling needs of electric drives, batteries, gearbox and hybrid drive, gear oil coolers when they are unused. They will also hold a reserve reservoir when these systems are in use.


Being in contact with the underwater hull form will facilitate the transfer of excess heat from the coolant to the seawater. They will also help us significantly reduce the use of seawater within the engine room.


Our calculations revealed that we

Heat flow diagram for the water glycol cooling system
Heat flow diagram for the water glycol cooling system

need approximately 6kW of thermal cooling capacity per tank. Under static fluid conditions (such as at anchor), we need 1 m2 of tank/seawater surface to contact the fluid. I’m guessing at the system capacity, but with small-bore pipes, the system volume is probably less than 100 litres.



The Solution for the new water-glycol cooling system

Water Glycol Cooling System Design with twice more space for sea water
Water glycol cooling system design with twice more space for sea water