DieselShip's Online Content Library

Q9) Sketch and describe a contra flow type heat exchanger for the auxiliary engine applications. (16)

Q4. (a) How are heat exchangers protected from the effects of corrosion? (8)

(b) What are the problems associated with biofouling? (8)

Q6. A jacket cooling water, plate type cooler for the engine system is stripped open during overhaul for survey purposes, State out a list of components, parts or areas, which you would like to particularly check yourself before the survey. (16)

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).

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

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.

Q3. With reference to a tubular heat exchanger, state the various types used on board a ship and explain with sketches how the construction, flow pattern, baffles, differ from each other depending upon the medium in use.

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)

Q2. (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)