An uninsulated, 3-nom sch-40, (D-3.068 in, D=3.5 in), carbon steel pipe (kst-26 Btu/hr-ft-R) carries 1000 lbm/hr...

  

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An uninsulated, 3-nom sch-40, (D₁-3.068 in, D₂=3.5 in), carbon steel pipe (kst-26 Btu/hr-ft-R) carries 1000 lbm/hr of saturated steam at 440°F. The steam enters the pipe section as a saturated vapor. The convection coefficient between the steam and the pipe inner wall is h = 50 Btu/hr-ft²-R. The uninsulated pipe is above ground, and the convection coefficient between the outer pipe wall and the air is h = 20 Btu/hr-ft²-R. The air is at 60°F. a. (5 pt) Draw the thermal circuit with temperature nodes and thermal resistances. b. (5 pt) Identify each thermal resistance. Write the form of the resistance on the circuit. C. (5 pt) Compute each thermal resistance per unit length, giving correct units. d. (10 pt) Compute the heat transfer from the pipe, per unit length. e. (5 pt) Assuming the enthalpy of vaporization of the steam is hig = 785.7 Btu/lbm, compute the length of pipe it would take to convert the steam from saturated vapor to saturated liquid. An uninsulated, 3-nom sch-40, (D₁-3.068 in, D₂=3.5 in), carbon steel pipe (kst-26 Btu/hr-ft-R) carries 1000 lbm/hr of saturated steam at 440°F. The steam enters the pipe section as a saturated vapor. The convection coefficient between the steam and the pipe inner wall is h = 50 Btu/hr-ft²-R. The uninsulated pipe is above ground, and the convection coefficient between the outer pipe wall and the air is h = 20 Btu/hr-ft²-R. The air is at 60°F. a. (5 pt) Draw the thermal circuit with temperature nodes and thermal resistances. b. (5 pt) Identify each thermal resistance. Write the form of the resistance on the circuit. C. (5 pt) Compute each thermal resistance per unit length, giving correct units. d. (10 pt) Compute the heat transfer from the pipe, per unit length. e. (5 pt) Assuming the enthalpy of vaporization of the steam is hig = 785.7 Btu/lbm, compute the length of pipe it would take to convert the steam from saturated vapor to saturated liquid.