Question

Cooling water available at 10C is used to condense steam at 30C in the condenser of a power plant at a rate of 0.15 kg/s by circulating the cooling water through a bank of 5 m long 1.2 cm internal diameter thin copper tubes. Water enters the tubes at a mean velocity of 4 m/s and leaves at a temperature of 24 C. The tubes are nearly isothermal at 30 C. Determine the average heat transfer coefficient between the water, the tubes, and the number of tubes needed to achieve the indicated heat transfer rate in the condenser.

Answer 1

To determine the average heat transfer coefficient between the cooling water and the tubes, use the heat transfer equation and the given values. The number of tubes needed for the indicated heat transfer rate can be found by rearranging the equation.

Step-by-step explanation:

The average heat transfer coefficient between the cooling water and the thin copper tubes can be determined using the equation:

Q = U × A × ΔT

Where Q is the heat transfer rate, U is the heat transfer coefficient, A is the surface area of the tubes, and ΔT is the temperature difference between the water and the tubes.

To find the number of tubes needed to achieve the indicated heat transfer rate, we need to rearrange the equation as:

N = Q / (U × A × ΔT)

Where N is the number of tubes.

By substituting the given values into the equations, we can solve for U and N.

Answer 2

Solved Cooling water available at 10°C is used to condense

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Cooling water available at 10°C is used to condense steam at 30°C in the condenser of a power plant at a rate of 0.15 kg/s by circulating the cooling water ...

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Top answer:

Solution:- Given data:- Inlet temperature of cooling water T_(i)=10^circ steam and surface temperature of tubes T_s=30^circ .