Test on Heat Exchanger

Define heat exchanger

Answer explanation

A heat exchanger is a device that transfers heat between two or more fluids without mixing them. It is commonly used in heating, cooling, and energy recovery applications to improve efficiency.

Define temperature.

Answer explanation

Temperature is a measure of the average kinetic energy of particles in a substance, indicating how hot or cold it is. It is typically measured in degrees Celsius, Fahrenheit, or Kelvin.

Define heat.

Answer explanation

Heat is the form of energy that is transferred between systems or objects with different temperatures, flowing from the hotter to the cooler until thermal equilibrium is reached.

Define sensible heat.

Answer explanation

Sensible heat is the energy exchanged by a thermodynamic system that results in a temperature change without a phase change. It can be felt and measured, unlike latent heat, which involves phase changes.

Define latent heat.

Answer explanation

Latent heat is the amount of heat energy absorbed or released by a substance during a phase change, such as melting or boiling, without changing its temperature. It is crucial in understanding thermal processes.

Purpose of heat transfer is to ______________.

1. a) To heat cooler fluid by means of hotter fluid. 

2. b) To reduce the temperature of hot fluid by means of cooler fluid. 

3. c) To boil a liquid by means of hotter fluid. 

4. d) To condense gaseous fluid by means of a cooler fluid. 

• Only b is correct

• a & b

• Only a is correct

• all of the above

• b & c

Answer explanation

The purpose of heat transfer is primarily to reduce the temperature of hot fluid by means of cooler fluid, making option b the only correct choice. Options a, c, and d describe specific scenarios but do not capture the general purpose.

What are the three ways in which heat can be transferred?

Answer explanation

Heat can be transferred in three ways: conduction (through direct contact), convection (through fluid movement), and radiation (through electromagnetic waves). Each method plays a crucial role in thermal energy transfer.

Draw evaporation curve at atmospheric pressure and show sensible heat and latent heat.

Answer explanation

The evaporation curve at atmospheric pressure shows temperature vs. heat input. Sensible heat raises temperature, while latent heat represents the energy absorbed during phase change from liquid to vapor, without temperature change.

Name two types of fluid flow.

Answer explanation

Two types of fluid flow are laminar flow, where fluid moves in parallel layers, and turbulent flow, characterized by chaotic and irregular movement. These classifications help in understanding fluid behavior in various applications.

Some examples of heat exchanger are.

1. Condenser and evaporator. 

2. Automobile radiators. 

3. Airconditioning unit.  

4. HRSG in power plant. 

• All the above are correct.

• Condenser and evaporator.

• Airconditioning unit.

• Automobile radiators.

• HRSG in power plant.

Answer explanation

All the options listed are examples of heat exchangers, including condensers, evaporators, automobile radiators, air conditioning units, and HRSG in power plants, making 'All the above are correct' the right choice.