A heat recovery device involves transferring energy from the hot flue gases passing through an annular region to pressurized water flowing through the inner tube of the annulus. The inner tube has inner and outer diameters of 24 and 30 mm and is connected by 8 struts to an insulated outer tube of 50-mm diameter. Each strut is 3 mm thick and is integrally fabricated with the inner tube from carbon steel (k = 50 W/m-K). +||+1= - t = 3 mm ↑ Di2 D₁,1 ↓ h Water Gas Consider conditions for which water at 300 K flows through the inner tube at 0.161 kg/s while flue gases at 800 K flow through the annulus, maintaining a convection coefficient of 100 W/m².K on both the struts and the outer surface of the inner tube. What is the rate of heat transfer per unit length of tube from gas to the water? Use the Dittus-Boelter equation to obtain the water-side convection coefficient. Determine the rate of heat transfer per unit length of tube from gas to the water, in W/m. q= i W/m Do

A shell-and-tube heat exchanger is used to cool compressed liquid methanol from 176 °F to 104 °F. The methanol flows on the shell side of the exchanger. The coolant is water that rises in temperature from 50 °F to 86 °F and flows within the tubes at a rate of 68.9 kg s1. Finding the appropriate thermophysical data and applying the proper equations, you are required to do the following: (a) Calculate i) methanol mass flow rate in the exchanger, ii) methanol volumetric flowrate at the inlet of the exchanger. (b) i) For the counter-current flow of the fluids calculate the log temperature difference, ii) explain the purpose of calculating this difference, iii) explain, quantitatively, why is the counter-current flow in heat exchangers preferred to co-current flow. mean

The condenser of a large thermal power plant is a body-tube type heat exchanger consisting of a single body and 30000 pipes with two passes each. The pipes are thin-walled with an inner diameter of 25 mm, and steam condenses on the outer surfaces of the pipes with a convection coefficient of 11000 W / m2.K. The heat transfer required by the heat exchanger is 2000 MW, and it is provided by the flow of water through the pipes at a flow rate of 30000 kg / h. Water enters at 20 ° C, steam condenses at 50 ° C. Calculate the temperature of the cooling water leaving the condenser? Determine the required pipe length per pass? The properties of water at Tort = 300 K; Cp = 4180 j / kgK, μ = 855 × 10--6 Ns / m2, k = 0.613 W / mK, Pr = 5.83.

A heat recovery device involves transferring energy from the hot flue gases passing through an annular region to pressurized water flowing through the inner tube of the annulus. The inner tube has inner and outer diameters of 24 and 30 mm and is connected by 8 struts to an insulated outer tube of 45-mm diameter. Each strut is 3 mm thick and is integrally fabricated with the inner tube from carbon steel (k = 50 W/m-K). D₂ D₁,2 Dil ↓ Water 1=3 mm Gas h Consider conditions for which water at 300 K flows through the inner tube at 0.161 kg/s while flue gases at 800 K flow through the annulus, maintaining a convection coefficient of 100 W/m².K on both the struts and the outer surface of the inner tube. What is the rate of heat transfer per unit length of tube from gas to the water? Use the Dittus-Boelter equation to obtain the water-side convection coefficient. Determine the rate of heat transfer per unit length of tube from gas to the water, in W/m. 9 = i W/m