Double pipe heat exchangers are used__________________?
A. When heat transfer area required is very high
B. When heat transfer area required is very low, i.e. (100-200 ft2).
C. Because it occupies less floor area
D. Because it is less costly
A. When heat transfer area required is very high
B. When heat transfer area required is very low, i.e. (100-200 ft2).
C. Because it occupies less floor area
D. Because it is less costly
A. 50 -100 Kcal/hr.m2.°C
B. 50 -100 W/m2.°K
C. 50 -100 BTU/hr. ft.2°F
D. 1000 – 1500 BTU/hr. ft.2°F
A. Increases
B. Decreases
C. Remains unchanged
D. May increase or decrease; depends on its composition
A. Temperature of the heating surface is less than the boiling point of the liquid
B. Temperature of the heating surface is more than the boiling point of the liquid
C. Bubbles from heating surface are absorbed by the mass of the liquid
D. Very large vapour space is necessary
A. High pressure
B. Vacuum
C. Backward feed
D. None of these
A. (COP)R = (COP)HP = 0.6
B. (COP)R = 2.5; (COP)HP = 1.5
C. (COP)R = 1.5; (COP)HP = 2.5
D. (COP)R = (COP)HP = 2.5
A. Smaller than
B. Greater than
C. Equal to
D. Not related with