Question: a pipe carrying brine at 8c passes through a...
A pipe carrying brine at – 8°C passes through a room at 30°C.
The outside diameter of the pipe
is 15 cm and the convection coefficient has a value of 18 W/m2K. Determine the heat gain for
10 m length. In order to reduce the heat gain moulded insulations of 2.5 cm, 4 cm, 6 cm and 8 cm
thicknesses are available with conductivities of 0.06 W/mK. Determine the percentage reduction
due to each of these. If the cost of heat is Rs. 3/1000 kJ determine in each case the break even
cost per m3 of insulation material if the investment is to be realized in one year of operation. The
unit is in operation for 7000 hr/year.