DieselShip's Online Content Library

Q8. (a) Describe how the leak of a leaky tube in a heat exchanger is detected? How to rectify leaky tube? (8)

(b) Describe with reasons for the poor performance of a heat exchanger and actions to rectify the same (8).

Q4. (a) With respect to 'plate type' heat exchanger, describe its construction and assembly. Also mention the material used for plates, gaskets, frames etc. (6)

(b) What are the advantages and disadvantages of using plate type heat exchanger? (5)

(c) How leaky plates are determined and identified (5)

Q9. With reference to multi-tubular heat exchangers explain:

(A) How and where impingement attack is likely to occur in the tubes

(B) Why is it desirable that coolant flow rate should not exceed that required to maintain correct fluid temperature

(C) Ample well-shaped water boxes and smooth tube inlets are desirable

(D) Partial obstruction of tube bore is a common cause of tube failure

Q5. A Plate type LT cooler of the centralized cooling water system on your ship is showing poor performance. What measures you would initiate to rectify the problem and improve the performance. (16)

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Q8. A LT cooler of the centralized cooling water system on your ship is showing poor performance. What measures you would initiate to rectify the problem and improve the performance. (16)

Q9. With reference to tubular heat exchangers explain:

a) How differential movement tubes and body is accommodated when the tube plates are rigidly located in the body,

b) How and why turbulence is imparted to fluid flow through the tubes,

c) Why it has become possible to discard sacrificial anodes in sea water coolers,

d) What is meant by the term ‘guided flow’, with particular reference to oil heaters.

Q8. i) What is the basic function of heat exchanger? (3)

ii) Draw a line diagram showing the temperature gradient between the fluids at an intermediate heat conductive wall of a heat exchanger. (3)

iii) Explain with respect to flow pattern a parallel flow: (10)

a) i) parallel flow, ii) contraflow

b) i) turbulent flow, ii) streamline flow (for liquid inside tubes)

Q5. (a) Draw a simple line sketch of a 'shell and tube' cooler, clearly labelling its parts. (6)

(b) Describe the system. (4)

(c) Name common defects found. (3)

(d) What periodical maintenance needs to be carried out. (3)

Q1. (a) How does fouling affect the performance of a heat exchanger? (4)

(b) Describe the types of plugs used to plug the ends of a leaky heat exchanger tubes. (6)

(c) What is a differential pressure gauge? Where is it used? (6)

Q5. a) Describe shell and tube type heat exchanger and its function with the aid of a diagrammatic sketch, naming each part. (8)

b) Describe the physical cleaning procedure of cleaning tubes. (4)

c) Describe the Chemical cleaning of the shell side of the heat exchanger. (4)

Q4. a) Describe how leak in leaky tube in Heat exchanger is detected? How to rectify leaky tube? (8)

b) Describe how division plate on the inlet and outlet end is detected? (4)

c) Describe reasons for poor performance of heat exchanger and action to rectify the same. (4)

Q3. a) What is the working principle of a plate type cooler on a ship, and what are its main components? How does it differ from other types of heat exchangers used on ships? (6)

b) What materials are commonly used for the packing in plate type coolers on board ships, and how do these materials impact the efficiency and durability of the cooler? (5)

c) Describe the process of back flushing a plate type cooler on a ship. Why is back flushing important, and what potential issues can it prevent or mitigate. (5)

Q2. (a) Describe how leak in a Heat exchanger tube is detected? How to rectify leaky tube? (8)

(b) What are the common methods to enhance heat transfer of heat exchanger? (4)

(c) Describe reasons for poor performance of heat exchanger and actions to rectify the same. (4)