250+ TOP MCQs on Heat Exchangers and Answers

Thermal Engineering Multiple Choice Questions on “Heat Exchangers”.

1. A periodic type heat exchanger is known as _____
a) Direct contact heat exchanger
b) Indirect contact heat exchanger
c) Recuperator
d) Regenerator

Answer: d
Clarification: A periodic type heat exchanger is known as regenerator. Recuperator are heat exchanger in which two fluids are separated by a wall.

2. Surface heat exchangers are also known as _______
a) Direct contact heat exchanger
b) Indirect contact heat exchanger
c) Recuperator
d) Regenerator

Answer: c
Clarification: Recuperator are heat exchanger in which two fluids are separated by a wall. Recuperator is also called surface heat exchangers. In direct flow heat exchanger two fluids exchange heat by coming in direct contact.

3. In which type of heat exchanger the same space is occupied by the hot and cold gases, between which heat is exchanged?
a) Recuperator
b) Regenerator
c) Direct contact heat exchanger
d) Indirect contact heat exchanger

Answer: b
Clarification: A periodic type heat exchanger is known as regenerator. Regenerator heat exchanger in which the same space is occupied by the hot and cold gases, between which heat is exchanged. Recuperator are heat exchanger in which two fluids are separated by a wall.

4. Which of the following is not an application of regenerator?
a) Jet condenser
b) Steam power plant
c) Oxygen producer
d) Blast furnace

Answer: a
Clarification: Regenerators find their applications in steam power plant, oxygen producer and blast furnace. The application of direct contact type heat exchanger are open feed water heaters, de-super heater and jet condensers.

5. What property of cold fluid remains constant in case of evaporator?
a) Volume
b) Temperature
c) Entropy
d) Enthalpy

Answer: b
Clarification: In case of evaporator the temperature remains constant as pressure does not change. The temperature of hot fluid decreases.

6. LMTD in case of condenser will ________ for counter and parallel flow heat exchanger.
a) Remain same
b) Not be equal
c) Cannot be determined
d) Will not change with time

Answer: a
Clarification: In case of condenser and evaporator ∆T1 and ∆T2 remains same in case of counter and parallel flow heat exchanger. Therefore LMTD in case of condenser will be same for counter and parallel flow heat exchangers.

7. How many categories heat exchanger can be classified based on nature of heat exchange process?
a) 1
b) 2
c) 3
d) 4

Answer: c
Clarification: The classification of heat exchanger on the basis of nature of heat exchange:

• Direct contact
• Recuperator
• Regenerator

10. In which of the following recuperator heat exchanger is not used?
a) Evaporator
b) Chemical factories
c) Automobile radiators
d) Condensers

Answer: b
Clarification: Recuperator are heat exchanger in which two fluids are separated by a wall. Recuperator is not used in chemical factories. It is used in condenser, evaporator and automobile radiator.

11. Number of categories heat exchanger can be classified based on the direction of flow of fluids is ______
a) 1
b) 2
c) 3
d) 4
Answer: c
Clarification: The classification of heat exchanger on the basis of the direction of flow of fluids are:

• Counter flow heat exchanger
• Parallel flow heat exchanger
• Cross flow heat exchangers

12. Number of categories heat exchanger can be classified based on the mechanical design of heat exchanger surface is ______
a) 1
b) 2
c) 3
d) 4

Answer: c
Clarification: The classification of heat exchanger on the basis of the mechanical design of heat exchanger surface:

• Concentric tube
• Shell and tube
• Multiple shell

13. Number of categories heat exchanger can be classified based on the physical state of heat exchanging fluid is ____
a) 1
b) 2
c) 3
d) 4
Answer: b
Clarification: The classification of heat exchanger on the basis of the physical state of heat exchanging fluid:
14. In which of the following type of heat exchanger the heat exchange between the two fluids occur by their complete physical mixing?
a) Direct contact heat exchanger
b) Indirect contact heat exchanger
c) Recuperator
d) Regenerator

Answer: a
Clarification: In direct contact type of heat exchanger the heat exchange between the two fluids occur by their complete physical mixing. Recuperator are heat exchanger in which two fluids are separated by a wall. Regenerator heat exchanger in which the same space is occupied by the hot and cold gases, between which heat is exchanged.