3-151 Consider two tubes of the same diameter (D = 20 cm), reigth, and surface temperature...
Steam in a heating system flows through tubes whose outer
diameter is D1 =3 cm and whose walls are maintained at a
temperature of 120oC. Circular aluminum fins (k = 180
W/m.oC) of outer diameters D2 = 6 cm and
constant thickness t = 2mm are attached to the
tubes. The space between the fins is 3 mm. Heat is
transferred to the surrounding air at
T∞ = 25 oC, with a
convection heat transfer coefficient of h = 60
W/m2.oC.
Determine the...
6. Problem 3 (20 points): A Steam in a heating system flows through tubes whose outer diameter is 3 cm and whose walls are maintained at a temperature of 120°C. Circular aluminum alloy fins (k = 180 W/m.) of outer diameter 6 cm and constant thickness t 2 mm are attached to the tube, as shown in the figure below. The space between the fins is 3 mm, and thus there are 200 fins per meter length of the tube....
Problem 2: Heat exchanger (25 points) Cold water (op 4179 J/kg K) enters the tubes of a heat exchanger at 20 °C at a rate of 3 kgs. while hot oil (cp 2200 J/kg.K) enters the shell at 130 C at the same mass flow rate and leaves at 60°C The heat exchanger consistsoftwo shells and 20 tubes, each executing four passes (two passes per shell). If the W/m2-K, assume the tube wall is very thin with convective heat transfer...
3. A thermocouple is used to measure the surface temperature of an object. The center of a thermocouple bead of diameter D-100 μm is positioned at a distance 10 μm from the surface of interest. The two thermocouple wires, each of diameter d = 1 mm and length L-250 mm, are held by a large manipulator that is at a temperature of Tm-25 °C. The thermal conductivities of the Nicrosil and Nisil thermocouple wires are Kvic respectively. We can neglect...
Two large parallel plates with surface conditions approximating those of a blackbody are maintained at 800°C and 100°C, respectively. Determine the rate of heal transfer by radiation between the plates in Wim and the radiative heat transfer coefficient in W/m K ) 12 Write down the one-dimensional sent heal conduction equation for a plane wall with constant thermal conductivity and heat generation in its simplest form, and indicate what each variable represents 13 Write down the one-dimensional transient heat conduction...
summatize the following info and break them into differeng key points. write them in yojr own words
apartus
6.1 Introduction—The design of a successful hot box appa- ratus is influenced by many factors. Before beginning the design of an apparatus meeting this standard, the designer shall review the discussion on the limitations and accuracy, Section 13, discussions of the energy flows in a hot box, Annex A2, the metering box wall loss flow, Annex A3, and flanking loss, Annex...