A 5m long heated pipe is used heat up water from 15°C to 65°C. Water flow through the pipe is 10liter/min. The heating gives a constant heat flow in all parts of the pipes surface. The inner and outer diameter of the pipe is 30 and 50 mm, respectively. Calculate the heat transferred to the water and the inner surface temperature of the pipe at the end (point where water leaves the pipe at temperature of 65oC)
The Attempt at a Solution
When calculating the heat transferred to the water I used
Q = m,massflow*Cp*dT.
Cp was taken at the "medium" temperature of 40 celsius. My question is: Can you use the heat transferred to the water, i.e. Q, in calculating the wall temperatures at a given point in the pipe? I would then use Q = h*A,i*(Twall-65) and solve for Twall. h is calculated by using the Reynolds/Nusselt number,