Plz show all steps Electrical heating tape is wrapped around a PVC pipe of insid

Question

Plz show all steps

Electrical heating tape is wrapped around a PVC pipe of inside diameter (D,) 6 cm and outside diameter (D0) 8 cm The outside surface temperature of this pipe is measured to be 25 degree C and it is desirable to keep the inside surface temperature to a minimum of 5 degree C It may be assumed that the outside of the heating tape is sufficiently insulated so that all of the heat goes into the PVC For a 2-m long section of pipe wrapped in heating tape, determine the tape's heat rate (in M) needed to maintain these temperature conditions. The thennal conductivity (k) of the PVC is given as a constant 0 19 W/m-K Also, a; ume 1-D steady-state heat transfer with no internal heat

Explanation / Answer

diameter of inner surface = 6cm

so radius of inner = 3cm

diameter 0f outer surface=8cm

radius = 4cm

so thickness = 2cm = ro-ri = 0.02m

q = 2 ? k (ti - to) / ln(ro / ri) .............1

where d is thickness

Tout=25+273=298k, Tin=5+273=278k which is given

now substituting all these values in equation 1 we get

Q/t = heat transfer rate = 0.19 * 2*pi*(298-278)/ln(4/3) = 82.9w/s

for unit length heat transfer rate is 82.9W/s

then for length = 2m , heat transfer = 2*82.9 = 165.8W/s

heat transfer rate is 165.8 W/s

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