Question

A 10-mm diameter tube has a maintained surface temperature of 200°C. Engine oil enters the tube at 70°C at a flow rate of 0.5 kg/s and exits at 105°C. Find the length, in m, of the tube and well as the corresponding heat transfer rate, in W. Assume fully developed flow and use the Dittus–Boelter equation to calculate the average Nusselt number.

q = . L =

Answer #1

Used engine oil flows at 0.025 m/s through a 12.5-mm-diameter
tube. The oil enters the tube at a temperature of 27 ºC, while the
tube surface temperature is maintained at 87º C. Determine the oil
outlet temperature for a 100-m and the total heat transfer.

Pressurized Water is heated in a thin tube with a diameter of 60
mm. water enters with a mass flow rate of 0.01 kg/s and an inlet
temperature of 20°C. a uniform heat flux of 2000 W/m2 is applied to
the tube. What is the required length of the tube to obtain an exit
temperature of 80°C for the water? If the water reaches 80°C at the
outlet, what is the surface temperature of the tube at the
outlet?

A 1.5cm inside diameter tube has water flowing in it at a flow
rate such that the Reynolds number is 50,000. The water enters the
tube at 10oC and the tube wall temperature is maintained
at 15oC higher than the average water bulk temperature.
Calculate:
a) the amount of heat transfer required to achieve a
10oC increase in water temperature (in W)
b) the length of the tube to achieve this amount of heat
transfer (in meters)

Water at 15°C enters a tube of 2 cm of diameter with flow rate
3953 kg/h. Assume the ratio L/D>10, and the wall temperature is
constant at 80-C. The outlet temperature is 50°C The properties of
water at the film temperature are density rho = p = 985 kg/m3,
specific heat Cp = 4180 J/kgk, conductivity k = 0.651 W/mK, dynamic
viscosity mu= u = 4.71 × 10- kg/ms, At the wall temperature of 80°C
we have dynamic viscosity muw=...

A 1 to 2 baffled shell-and-tube type heat exchanger is
used as an
engine oil cooler. Cooling water flows through tubes at 25 °C at
a
rate of 8.16 kg/s and exits at 35 °C. The inlet and outlet
temperatures of the engine oil are 65 and 55 °C, respectively.
The
heat exchanger has 12.25-in. I.D. shell, and 18 BWG and
0.75-in.
O.D. tubes. A total of 160 tubes are laid out on a 15/16-in.
triangular
pitch. By assuming Ro...

Water at a flow rate of 60 kg/s enters the shell-side
of a baffled shell-and-tube heat exchanger at 35 °C and leaves at
25 °C. The heat will be transferred to 150 kg/s of raw water coming
from a supply at 15 °C. You are requested to design the heat
exchanger for this purpose. A single shell and single tube pass is
preferable. The tube diameter is ¾ in. (19 mm outer diameter with
16 mm inner diameter) and tubes...

Consider the flow of oil at 10?C in a 40-cm diameter pipeline at
an average velocity of 0.5 m/s. A 1500-m long section of the
pipeline passes through icy waters of a lake at 0?C. Disregarding
the thermal resistance of the pipe material, determine (a) the
temperature of the oil when the pipe leaves the lake (b) the rate
of heat transfer from the oil and (c) the pressure losses in the
pipe. Assume the flow is hydro-dynamically fully developed.

An aluminum fin 1.6 mm thick surrounds a tube 2.5 cm
in diameter. The length
of the fin is 12.5 mm. The tube-wall temperature is 200◦C, and the
environment
temperature is 20◦C. The heat-transfer coefficient is 60 W/m2 · ◦C.
Consider the heat dissipated in a pipe 1.20 m long if the fins are
4.2 mm apart from center to center
Explain your procedure with formulas

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,...

Oil enters a counterflow heat exchanger at 600 K with a mass
flow rate of 10 kg/s and exits at 350 K. A separate stream of
liquid water enters at 20°C, 5 bar. Each stream experiences no
significant change in pressure. Stray heat transfer with the
surroundings of the heat exchanger and kinetic and potential energy
effects can be ignored. The specific heat of the oil is constant,
c = 2 kJ/kg · K.
If the designer wants to ensure...

ADVERTISEMENT

Get Answers For Free

Most questions answered within 1 hours.

ADVERTISEMENT

asked 9 minutes ago

asked 14 minutes ago

asked 27 minutes ago

asked 31 minutes ago

asked 41 minutes ago

asked 44 minutes ago

asked 45 minutes ago

asked 50 minutes ago

asked 52 minutes ago

asked 58 minutes ago

asked 1 hour ago

asked 1 hour ago