Problem 1
10°C water is flowing in a 10-mm diameter smooth tube. The mass flow rate of the water is 0.15 kg/s. The water will be heated to 50°C by having it flow through a heated section of the tube that is being maintained at a constant temperature of 90°C. Find the needed length of the heated section of the tube.
Problem 2
10°C water is flowing in a 10-mm internal-diameter smooth tube. The mass flow rate of the water is 0.15 kg/s. The water will be heated by passing it through a 3-m long section of the tube where the surface of the tube is being maintained at a constant temperature of 90°C. Find the temperature of the water when it exits the heated section of the tube.
Problem 3
40°C water is flowing in a 3.2-mm inside-diameter smooth tube. The mass flow rate of the water is 0.002 kg/s. The water will be cooled to 10°C by passing it through a section of the tube where the tube wall is being maintained at a constant temperature of 0°C. Find the needed length of the cold section of the tube.