Marine Engine Systems Merchant Marine Training Centre 2

Marine Engine Systems Merchant Marine Training Centre วชาการเปนเลศ เชดชคณธรรม ผนำ 2

Cooling Water System Merchant Marine Training Centre วชาการเปนเลศ เชดชคณธรรม ผนำ 3

Although there is a lot of sea water , marine diesel engines do not use it to cool the hottest parts of the engine. This is because sea water causes corrosion. Fresh water or distilled water is used instead. The fresh water is cooled by the sea water. Chemicals are used in the fresh water to prevent corrosion. Some ships have evaporators to make their own distilled water and do not use any sea water. Merchant Marine Training Centre 4

Cooling System Process The cooling water pumps pump water around the engine. The water passes through the engine to remove heat from the cylinder liners, cylinder heads, and turbo chargers (sometimes). Distilled water is used for this process. After passing through the engine, sea water is used to cool the distilled water. Co 0 ling Water Pumps Three way control valve Header Tank The temperature of the cooling water system is controlled by a three way control valve. The temperature of the system is very important. If the water is too cold it will damage or crack parts of the engine. If the water is too hot it will not remove heat from the engine and cause damage as well. There are two different types of cooling system: LT = Low Temperature cooling and HT = High Temperature cooling. The cooling for the engine is HT and usually at around 78 – 82 o c. If there any leaks in the system there is a header tank, which can add more water to the system. There also vents in the system to let water out if there is too much water in the system. The header tank is usually small, and usually located high in the engine room. It is refilled by hand has an alarm so that we can know immediately if there is a leak. This tank is checked 3 or 4 times a day. The system also has a heater to make sure the cooling water is at the correct temperature when then engine is stopped. The heaters are also used to make sure that the engine is at the correct temperature before starting. Water Heater Please note: Noun / Verb Merchant Marine Training Centre วชาการเปนเลศ เชดชคณธรรม ผนำ 5

Cooling Water System Fresh Water Generator A drain tank is used when the engine is drained for maintenance. The water can not be released into the sea because it contains chemicals. Merchant Marine Training Centre วชาการเปนเลศ เชดชคณธรรม ผนำ 6

Cooling System Process What does the 3 way control valve do? What does ‘LT’ and ‘HT’ mean? What is the HT system used for? What is the deaeration vessel used for? What is the header tank or jacket water tank used for? Please note: Noun / Verb Merchant Marine Training Centre วชาการเปนเลศ เชดชคณธรรม ผนำ 7

Cooling System Process q. Jacket Water Tank / Header Tank q. Cooling Water Pump q. Fresh Water Generator q. Pre-Heater Pump q. Three Way Control Valve q. Deaeration Vessel q. Heater Please note: Noun / Verb Merchant Marine Training Centre วชาการเปนเลศ เชดชคณธรรม ผนำ 8

Engine Room Tour Merchant Marine Training Centre 9