Consider a long horizontal cylindrical pipe of external diameter 10 mm that is losing heat by convection to still air at 0oC. If the external surface of the pipe has a uniform temperature of 80oC, determine the rate of convection heat transfer per unit length of the pipe. The following properties may be assumed for air: = 1.127 kg·m-3 , k = 0.02665 W·m-1 ·K -1 , = 1.702 x 10-5 m2 ·s-1 , Pr = 0.724.
Consider a long horizontal cylindrical pipe of external diameter 10 mm that is losing heat by...
(c) Steam flows a pipe of external diameter 30 mm, where the pipe outer surface temperature is 130oC. Circular annular fins (k = 180 W·m-1·K-1) of outer diameter 60 mm and thickness 1 mm are fitted tightly to the pipe. Heat is transferred by convection (h=10 W·m-2·K-1) to the surrounding air at 20oC. (i) Determine the efficiency of a single fin. (ii) Determine the heat transfer rate for a single fin. (8 marks) (6 marks) (iii) Determine the effectiveness of...
A) Determine the convection heat transfer coefficient for the flow of air. [W/m2·°C] B) Determine the convection heat transfer coefficient for water. [W/m2·°C] The velocity of the fluid is 9 m/s in an 8-cm diameter and 7-m-long tube when the tube is subjected to uniform heat flux from all surfaces. Use fluid properties at 25°C. Water or Air D 8 cm L=7 m Given: The properties of air at 25°C are: k 0.02551 W/m."C v 1.562 10-5 m2/s Pr =...
A long cylindrical rod of diameter 220 mm with thermal conductivity 0.5 W/m-K expe riences uniform volumetric heat generation of 25,000 W/m3. The rod is encapsulated by a circular sleeve having 7 W/m K. The outer surface of the sleeve is exposed to cross flow of air at 25°C with a convection coefficient of 25 W/m2-K. Find the temperature at the interface between the rod and sleeve, and on the outer surface. an outer diameter of 410 mm and thermal...
S A 10-m-long section of an 8 cm (r=4 cm) of external diameter horizontal steam water pipe passes through a large room whose temperature is To =15°C. The pipe is insulated with an insulating material of conductivity k=0.01 W/m-°C and 1 cm thick. If the inner surface temperature of the pipe is 95 °C (at r2) and the pipe is exposed to a cross wind of 6.0 m/s, determine the rate of heat loss from the pipe (neglect radiation). Thermal...
QUESTION 5 A 12-m-long and 11-mm-inner-diameter pipe made of commercial steel is used to heat a liquid in an industrial process. The liquid enters the pipe with T; = 20°C, V=0.8 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 60°C. Assuming fully developed flow and taking the average fluid properties to be p = 992.1 kg/m2, k = 0.631 W/m-°C, Cp =...
A 10 m long stainless steel (AISI 347) pipe is delivering saturated liquid water at 140 °C. The inner and out diameter is 20cm and 22cm, respectively. Ambient air at 27 °C flows over this pipe as cross flow at 5 m/s. The convection heat transfer between internal surface and water is 200W/m^2*K. If you need the external surface temperature in finding property of air, you can assume the pipe external surface temperature is 127 °C. (1) Find the heat...
QUESTION 1 (10 marks) a) Write the Newton's law of heat convection in fluid using convection heat transfer coefficient, h (Wm2.K). Please explain the equation in terms of its driving force and resistancC (2 marks) (POUCOI/C2) b) Define the heat transfer rate, q,by inside and outside convection and wall conduction considering a stainless steel cylindrical pipe (inside radius, ri and outer radius, ) with fiberglass insulator (radius, s) in ą steady state condition as shown in Figure Q11 Steam with...
6 Water is heated in a pipe by exchanging heat with a warmer fluid that flows outside the pipe. Inside diameter of the pipe is dn 0.045 m and outside diameter dour0.05 m. Mean velocity of the water in the pipe is um-0.31 m/s and the bulk temperature is 323 K (density 988 kg m-3; viscosity 0.00055 kg m' sı. Pr 3.56, thermal conductivity k 0.64 W m1 Kt). The material of the pipe has thermal conductivity k 0.61 W...
4. A pure copper pipe with inner diameter Di-10 mm ard outer diameter Do-14 mm is surrounded by saturated steam with pressure p 172 bar and convection coefficient h 6000 carries water with mean velocity u- (a) Determine the convective heat transfer coefficient inside the pipe for water at mean temperature Tm 37° C (b) At this same location, determine the total thermal resistance (per unit length) between the water and the steam. (c) Determine the heat transfer rate (per...
1- Water is pumped through a 9 m long pipe with internal diameter of d-40 mm at the rate of 2.25 m3 per hour. The water inter the pipe at 30 °C and exit at 70°C. Determine: b) The convection heat transfer coefficient between the water and the pipe wall Ans. (103.5 Kw, 2604 W/m2.°C) 1- Water is pumped through a 9 m long pipe with internal diameter of d-40 mm at the rate of 2.25 m3 per hour. The...