The fresh water cooling systems of the main engines on your fishing vessel are configured as shown in the illustration. During normal engine operation which of the listed fresh water temperature locations would indicate the highest temperature? Illustration MO-0137
• Follow the direction of fresh water flow in the diagram from the engine outlet, through the coolers, and back to the engine inlet. • Understand that a heat exchanger removes heat from the fresh water, while the lube oil cooler can add some heat back into the fresh water. • Consider what the thermostatic control valve is doing during normal operation (regulating jacket water temperature by mixing cooled and bypassed water).
• Starting at the point where fresh water leaves the engine (its hottest point), in what order does it pass the thermostatic valve, the RW/FW heat exchanger, and the lube oil cooler? • After passing through the RW/FW heat exchanger, is the fresh water hotter or cooler than it was going in? How about after it passes the lube oil cooler? • Which of the labeled locations (A–D) is upstream of any cooling devices, and which are downstream of one or more cooling stages?
• Verify the flow arrows on the illustration so you’re certain which way the fresh water is moving. • Identify clearly which component is the raw water/fresh water heat exchanger and which is the lube oil cooler, then match them to choices A–D. • Make sure the point you pick is located before the major cooling of the fresh water, not after it has been cooled and possibly reheated.
No comments yet
Be the first to share your thoughts!