A diesel engine with a fresh water cooling system may use a radiator or keel cooler to:

A diesel engine with a fresh water cooling system may use a radiator or keel cooler to:

• A. Heat the coolant
• B. Give up its heat to an external cooling medium (such as air or seawater)
• C. Increase pressure
• D. Filter the water

Answer: (B)

The main idea is to reject engine heat to an external medium. In a fresh-water cooling loop, the engine heats the coolant, and that heat must be dumped somewhere outside the engine. A radiator or keel cooler serves as a heat exchanger for this purpose. In a radiator, hot coolant flows through finned tubes and is cooled by air flowing over the fins (often with a fan). The cooled coolant then returns to the engine. In a keel cooler, seawater flows around tubes connected to the coolant loop, taking up the heat from the coolant; the now-cooled coolant returns to the engine while the seawater carries away the heat. These devices do not primarily increase pressure or filter water; their purpose is to transfer heat from the engine coolant to an external medium.

The main idea is to reject engine heat to an external medium. In a fresh-water cooling loop, the engine heats the coolant, and that heat must be dumped somewhere outside the engine. A radiator or keel cooler serves as a heat exchanger for this purpose.

In a radiator, hot coolant flows through finned tubes and is cooled by air flowing over the fins (often with a fan). The cooled coolant then returns to the engine. In a keel cooler, seawater flows around tubes connected to the coolant loop, taking up the heat from the coolant; the now-cooled coolant returns to the engine while the seawater carries away the heat.

These devices do not primarily increase pressure or filter water; their purpose is to transfer heat from the engine coolant to an external medium.