For a heat exchanger, the inlet and outlet temperature for the hot fluid is 130℃ and 60℃, the inlet and outlet temperature for the cold fluid is 30℃ and 70℃, so the effectiveness of the heat exchanger is ?
A. 0.8
B. 0.7
C. 0.9
D. 0.6
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what is the biggest difference between the design calcluation and check calculation for the heat exchanger?
A. Whether kA is known or not
B. Whether heat transfer area A is known or nt
C. Wether the flow rate of the cold fluid is known or not
D. Wether the temperature of the cold fluid is known or not
The temperature correction factor is determined by the dimensionless factors P and R, what is the physical meaning of R?
A. The ratio of the actual temperature rise of the fluid 1 and the maximum temperature rise that can be achieved theoretically
B. The ratio of the specific heat of fluid 1 and fluid 2
C. The ratio of the actual temperature rise of the fluid 2 and the maximum temperature rise that can be achieved theoretically
D. The ratio of the thermal capacity of fluid 1 and fluid 2
Divided by the working type, heat exchangers can be classified into which of the following type?
A. Recuperative type, mixing type, regenerative type
B. Recuperative type and non-recuperative type
C. Double-pipe, shell and tube, plate
D. Compact and non-compact
For the process of heat transfer through a flat wall, which is the key factor that determins the heat transfer coeifficient?
A. The covective heat transfer coeifficient in the cold side
B. The covective heat transfer coeifficient in the hot side
C. The thickness and conductivity of the wall
D. All of the three above
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