a) if heat flux is changed from 20 to 200 W/m2 what is the Tm out in degrees C? Assume same fluid properties
b) if heat flux is changed from 20 to 60 W/m2, and length is changed to 20m from 30, what is the Tm out in degrees C?
a) if heat flux is changed from 20 to 200 W/m2 what is the Tm out...
A counter-flow heat exchanger is stated to have an overall heat transfer coefficient of 284 W/m2.K when operating at design and clean conditions. Hot fluid enters the tube side at 101°C and exits at 71°C, while cold fluid enters the shell side at 27°C and exits at 42°C. After a period of use, built-up scale in the heat exchanger gives a fouling factor of 0.0004 m2 K/W. The surface area is 93 m². Assume both hot and cold fluids have...
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 concentric-pipe parallel-flow heat exchanger is to heat water (cp = 4.18 kJ/kg.K) from 20°C to 80°C at a rate of 1.2 kg/s. The heating is to be accomplished by geothermal water (Cp =4.31 kJ/kg.K) available at 160°C at a mass flow rate of 2.0 kg/s. The inner pipe is thin-walled and has a diameter of 1.5 cm. If the overall heat transfer coefficient of the heat exchanger is 640 W/m2.K, determine the length of the pipe required to achieve...
Consider liquid water flowing over a flat plate of length L = 1 m. The water has the following properties: ρ-1000 kg/m3, Cp-4000 J/kgK. 10 3 kg/ ms, k 0.6 W/m . C μ Midway through the plate at x = 0.5 m, you measure a heat flux to the surface of: 05 m 3181 W/m2 You also measure an average heat flux to the surface over the length of the plate of: "4500 W/m2 Knowing the latter, and knowing...
Find the efficiency and heat flux per unit of width in W / m
coming out of the following triangular fin:
t = 2mm = 6mm To = 250 °C w = Fin width Air To= 20 °C h = 40 W/m2.K w=Largeur de l'ailette K = 240W/m.K
Water enters a 20-mm tube at 27°C with a flow rate of 450 kg/h. The rate of heat transfer from the tube wall to the fluid is given as q5'(W/m) - a x, where the coefficient a is 20 W/m2 and x (m) is the axial distance from the tube entrance. (a) Beginning with a properly defined differential control volume in the tube, derive an expression for the temperature distribution T m(x) of the water. Use this expression to determine...
Question: 1 What is the maximum heat flux (Critical Heat Flux) for HFE-7000 according to Kutateladze's maximum heat flux correlation, in W/m2? Use the Zuber Constant (pi/24) for C. Question: 2 What was the minimum heat flux data point (Leiden frost Point) at the bottom of the film-boiling region of Nukiyama's experiment, in W/m2? Can you expect a similar value in our experiment? Question: 3 Estimate the excess temperature at CHF for HFE-7000 using the Rohsenow equation and the results...
Problem 2: Heat exchanger (25 points) Cold water (op 4179 J/kg K) enters the tubes of a heat exchanger at 20 °C at a rate of 3 kgs. while hot oil (cp 2200 J/kg.K) enters the shell at 130 C at the same mass flow rate and leaves at 60°C The heat exchanger consistsoftwo shells and 20 tubes, each executing four passes (two passes per shell). If the W/m2-K, assume the tube wall is very thin with convective heat transfer...
3 (40 pts) An infinitely large plate of thickness 20 cm is insulated at the lower surface. Within the plate, heat is uniformly generated at a rate égen = 5 x 104 W/m2. The temperature of the air above the plate is known as Tair = (1 - sini z), where 1 = 3000 m and the origin of the coordinate system z starts from the upper surface of the plate. The physical properties of the plate: p = 7.9...
Required information A shell-and-tube heat exchanger is used for cooling 47 kg/s of a process stream flowing through the tubes from 160°C to 136°C. This heat exchanger has a total of 100 identical tubes. each with an inside diameter of 2.5 cm and negligible wall thickness. The average properties of the process stream are: p = 950 kg/m”, k = 0.50 W/mK, Cp=3.5 kJ/kg.K, and -20 mPas The coolant stream is water (cp=4.18 kJ/kg K) at a flow rate of...