Question

A horizontal pipe with an outer surface temperature of 80 * C and an outside diameter of 100 mm is located in a room at atmospheric pressure at 20 ° C. Find the required pipe length for the loss of heat from the pipe to 1 kW. (Physical properties for air k = 0.0287 W / mK, Pr = 0.70, v = 19x10-6 m² / s)

Answer #1

A long 8-cm-diameter steam pipe whose external surface
temperature is 90°C passes through some open area that is not
protected against the winds. Determine the rate of heat loss from
the pipe per unit of its length when the air is at 1 atm pressure
and 7°C and the wind is blowing across the pipe at a velocity of 47
km/h. The properties of air at 1 atm and the film temperature of
(Ts + T∞)/2 = (90 + 7)/2...

The surface temperature of 200 ft of 8-inch diameter
un-insulated pipe carrying steam at 335 F is 250 F. The pipe is
located in a room with air and surroundings at 50 F. The surface
emissivity of the pipe is 0.70. Calculate convection, radiation and
total heat loss from the pipe (Btu/hr). The pipe is insulated with
3 inches on insulation with thermal resistance R = 2 hr-ft2-F/Btu
per inch. The surface emissivity of the insulation is 0.70.
Calculate convection,...

Saturated steam at 1 atm condenses on the outer surface of a
vertical, 100-mm-diameter pipe 1 m long, having a uniform surface
temperature of 94 o C. Estimate the heat transfer rate to the pipe
and the total condensation rate.

A concentric tube heat exchanger is comprised of a stainless
steel (ks = 40 W/mK) inner pipe, NPS 2- nominal schedule
40 size (corresponding to an inner diameter of 52.5 mm and an outer
diameter of 60.3 mm), and an outer stainless steel pipe of NPS
3-nominal schedule 40 (ID = 77.9 mm, OD = 88.9 mm). The heat
exchanger has an effective length of 35 m.
The inner pipe fluid is ammonia (?a = 0.3 · 10?6
m2/s, cpa...

A 12 meter long and 12 mm inner diameter smooth pipe is used to
heat a liquid in an industrial process. The liquid enters the pipe
at a temperature of 25o C and a mean velocity of 0.80 m/s. A
uniform heat flux is maintained by an electric resistance heater
wrapped around the outer surface of the pipe so that the fluid
exits at 75o C. The fluid average properties are ? = 1000 kg/m3 ,
Cp = 4000 J/kg·K,...

Hydraulic oil is flowing through a 80 mm diameter horizontal
pipe with a flow rate of 1.5 litres per -3 second. At a certain
point the diameter changes to 5 cm. Assume the oil’s density is 870
kg.m . (a) Calculate the velocity in SI units through the wider
diameter section of the pipe. (b) Calculate the velocity in SI
units through the narrower section of the pipe. (c) What is the
pressure difference between the larger and smaller sections...

Steam at an average temperature of ?∞= 400°C flows through a
steel pipe. The inner and outer radii of the pipe are r1 = 4 cm and
r2 = 4.5 cm, respectively, and the outer surface of the pipe is
insulated with a layer of 50 mm thick-calcium silicate of thermal
conductivity of k = 0.5 W/m.K, and is maintained at 350 °C. If the
convection heat transfer coefficient on the inner surface of the
pipe is h = 65...

A concentric tube heat exchanger is comprised of a stainless
steel (ks = 40 W/mK) inner pipe, NPS 2- nominal schedule
40 size (corresponding to an inner diameter of 52.5 mm and an outer
diameter of 60.3 mm), and an outer stainless steel pipe of NPS
3-nominal schedule 40 (ID = 77.9 mm, OD = 88.9 mm). The heat
exchanger has an effective length of 35 m.
The inner pipe fluid is ammonia (va = 0.3 ·
10-6m2/s, cpa =...

Steam enters a horizontal 14-cm-diameter pipe as a saturated
vapor at 5 bar with a velocity of 10 m/s and exits at 4.5 bar with
a quality of 95%. Heat transfer from the pipe to the surroundings
at 291K takes place at an average outer surface temperature of 400
K. For operation at steady state, determine
(a) the velocity at the exit, in m/s.
(b) the rate of heat transfer from the pipe, in
kW.?
(c) the rate of entropy...

Steam enters a horizontal 14-cm-diameter pipe as a saturated
vapor at 5 bar with a velocity of 10 m/s and exits at 4.5 bar with
a quality of 95%. Heat transfer from the pipe to the surroundings
at 291K takes place at an average outer surface temperature of 400
K. For operation at steady state, determine
(a) the velocity at the exit, in m/s.
(b) the rate of heat transfer from the pipe, in
kW.?
(c) the rate of entropy...

ADVERTISEMENT

Get Answers For Free

Most questions answered within 1 hours.

ADVERTISEMENT

asked 4 minutes ago

asked 8 minutes ago

asked 13 minutes ago

asked 15 minutes ago

asked 22 minutes ago

asked 29 minutes ago

asked 30 minutes ago

asked 30 minutes ago

asked 34 minutes ago

asked 36 minutes ago

asked 39 minutes ago

asked 48 minutes ago