Heat Transfer - Study Mode
[#206] In a heat exchanger, one transfer unit means
Correct Answer
(A) A section of the exchanger in which change in temperature of one stream equals the average driving force in the section
[#207] When does the heat generated by fluid friction becomes appreciable compared to the heat transferred between the fluids?
Correct Answer
(A) At high fluid velocity
[#208] __________ chart is known as transient heat conduction chart.
Correct Answer
(B) Heisler's
Explanation
Solution: A Heisler's chart is used in the field of heat transfer to solve problems related to transient heat conduction. Transient heat conduction refers to the transfer of heat within a material over time, where the temperature distribution changes with time. Heisler's charts provide graphical solutions for the temperature distribution and heat transfer rate in various geometries (such as slabs, cylinders, and spheres) subjected to convective boundary conditions. These charts are particularly useful because they allow engineers to quickly estimate the thermal response of a system without needing complex calculations. The other options, such as Dirhing's , Mollier's , and Cox charts, are associated with different fields and are not used for solving transient heat conduction problems.
[#209] It is not preferable to use superheated steam in evaporators, because of its very
Correct Answer
(C) Low film co-efficient
[#210] Vent pipes are provided in a condenser to
Correct Answer
(A) Remove non-condensable gases