Chemical Heat Transfer

Radiation heat losses from satisfactorily insulated high pressure boiler may be about _____________ percent?

Byadmin March 2, 2019August 24, 2021

Radiation heat losses from satisfactorily insulated high pressure boiler may be about _____________ percent?

A. 1
B. 7
C. 18
D. 26

Chemical Heat Transfer

In a shell and tube type heat exchanger, the floating tube bundle heat arrangement is used________________?

In a shell and tube type heat exchanger, the floating tube bundle heat arrangement is used________________?

A. In low range of temperature differences
B. In high range of temperature differences
C. Because of its low cost
D. To prevent corrosion of the tube bundles

Read More In a shell and tube type heat exchanger, the floating tube bundle heat arrangement is used________________?
Chemical Heat Transfer

The unit of heat transfer co-efficient in SI unit is____________________?

The unit of heat transfer co-efficient in SI unit is____________________?

A. J/M2°K
B. W/m2°K
C. W/m°K
D. J/m°K

Read More The unit of heat transfer co-efficient in SI unit is____________________?
Chemical Heat Transfer

The equivalent diameter for pressure drop is ________________ that for heat transfer?

The equivalent diameter for pressure drop is ________________ that for heat transfer?

A. Smaller than
B. Greater than
C. Equal to
D. Not related with

Read More The equivalent diameter for pressure drop is ________________ that for heat transfer?
Chemical Heat Transfer

In the free convection regime of pool boiling, the heat flux is proportional to__________________?

In the free convection regime of pool boiling, the heat flux is proportional to__________________?

A. Δt1/2
B. Δt2
C. Δt5/4
D. Δt

Read More In the free convection regime of pool boiling, the heat flux is proportional to__________________?
Chemical Heat Transfer

A metal ball of radius 0.1 m at a uniform temperature of 90°C is left in air at 30°C. The density and the specific heat of the metal are 3000 kg/m3 and 0.4 kJ/kg.K respectively. The heat transfer co-efficient is 50 W/m2.K Neglecting the temperature gradients inside the ball, the time taken (in hours) for the ball to cool to 60°C is_________________?

A metal ball of radius 0.1 m at a uniform temperature of 90°C is left in air at 30°C. The density and the specific heat of the metal are 3000 kg/m3 and 0.4 kJ/kg.K respectively. The heat transfer co-efficient is 50 W/m2.K Neglecting the temperature gradients inside the ball, the time taken (in hours) for the ball to cool to 60°C is_________________?

A. 555
B. 55.5
C. 0.55
D. 0.15

Read More A metal ball of radius 0.1 m at a uniform temperature of 90°C is left in air at 30°C. The density and the specific heat of the metal are 3000 kg/m3 and 0.4 kJ/kg.K respectively. The heat transfer co-efficient is 50 W/m2.K Neglecting the temperature gradients inside the ball, the time taken (in hours) for the ball to cool to 60°C is_________________?
Chemical Heat Transfer

Heat transfer co-efficient equation for forced convection, Nu = 0.023 Re 0.8. Pr n, is not valid, if the value of __________________?

Heat transfer co-efficient equation for forced convection, Nu = 0.023 Re 0.8. Pr n, is not valid, if the value of __________________?

A. n = 0.4 is used for heating
B. n = 0.3 is used for cooling
C. Reynolds number for the flow involved is > 10000
D. Reynolds number for the flow involved is < 2100

Read More Heat transfer co-efficient equation for forced convection, Nu = 0.023 Re 0.8. Pr n, is not valid, if the value of __________________?