Question

heat exchanger is from 150 °C to 40 °C at a rate of 2 kg/s by water (Cp = 4180)/kg-K) that enters at 22 °C at a rate of 1.5 kg/s the diameter of the tube is 2.5 cm and its length is 6 m. Determine the tube in 2.5 cm and length is 6m determined the overall heat transfer coefficient of the heat exchanger

Answer 1

The overall heat transfer coefficient of the heat exchanger is 370.37 W/(m^2*°C)

Step-by-step explanation:

To determine the overall heat transfer coefficient of the heat exchanger, we can use the following equation:

Q = U*A*ΔT

Where:

• Q is the rate of heat transfer
• U is the overall heat transfer coefficient
• A is the surface area of the heat exchanger
• ΔT is the temperature difference between the hot and cold fluids

In this case, the rate of heat transfer (Q) is given as 2 kg/s and we can calculate the temperature difference (ΔT) as 150 °C - 40 °C = 110 °C.

Now, we need to calculate the surface area (A) of the heat exchanger. The surface area of a tube can be calculated using the formula:

A = π*d*L

Where:

• A is the surface area
• d is the diameter of the tube
• L is the length of the tube

Plugging in the values, we get:

A = π*(0.025 m)^2 * 6 m = 0.0047 m^2

Finally, we can determine the overall heat transfer coefficient (U) by rearranging the equation:

U = Q / (A*ΔT)

Plugging in the values, we get:

U = 2 kW / (0.0047 m^2 * 110 °C) = 370.37 W/(m^2*°C)