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A pipe is used for transporting boiling water in which the inner surface is at 100°C. The pipe is situated in surroundings where the ambient temperature is 10°C and the convection heat transfer coefficient is 70 W/m2 ⋅K. The wall thickness of the pipe is 3 mm, and its inner diameter is 30 mm. The pipe wall has a variable thermal conductivity given as
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HEAT+MASS TRANSFER:FUND.+APPL.
- An oil radiator has an outside surface area of 0.18 m2 and operates at a surface temperature of 85 degree Celsius. If air moves over the surface of the radiator at a temperature of 16 degree Celsius and gives rise to a heat transfer coefficient equal to 38.25 W/(m2-K). Find out the heat transfer flux? O 2923 W/m2 O 3801 W/m² O 2639 W/m² O 1659 W/m²arrow_forwardLiquid flows in a metal pipe with an inner diameter of D1 = 22 mm and an outer diameter of D2 = 32 mm. The thermal conductivity of the pipe wall is 12 W/m-K. The inner surface of the pipe is coated with a thin polyvinylidene chloride (PVDC) lining. Along a length of 1 m, the pipe outer surface is exposed to convection heat transfer with hot gas, at To = 100°C and h= 5 W/m².K, and thermal radiation with a surrounding at Tsurr = 100°C. The emissivity at the pipe outer surface is 0.3. The liquid flowing inside the pipe has a convection heat transfer coefficient of 50 W/m²K. If the outer surface of the pipe is at 85°C, determine the temperature at the PVDC lining and the temperature of the liquid.arrow_forwardIn a thermal power plant, a horizontal copper pipe of "D" diameter, "L" length and thickness 1.7 cm enters into the boiler that has the thermal conductivity as 0.36 W/mK. The boiler is maintained at 104°C and temperature of the water that flows inside the pipe is at 31°C. If the energy transfer (Q) is 117126 kJ in 6 hours. Determine the Heat transfer rate, Surface area of the pipe and Diameter & Length of the pipe, if D = 0.017 L (Please Solve the problem in a paper and upload in the separate submission link provided and also fill the answers without the unit in the box below) Change in Temperature (in K) Heat Transfer Rate (in W) Surface Area of the Pipe (m³)arrow_forward
- H.W. Q: An aluminum pan whose thermal conductivity is 237 W/m-°C has a flat bottom with diameter 20 cm and thickness 0.4 cm. Heat is transferred steadily to boiling water in the pan through its bottom at a rate of 800 W. If the inner surface of the bottom of the pan is at 105°C, determine the temperature of the outer surface of the bottom of the pan. 105°C 0.4 cm Answer: T= 105.43 °C 800 W 7arrow_forwardA pipe 30 m long with an outer diameter of 75 mm is used to deliver steam at a rate of 1500 kg / hour. The vapor pressure is 198.53 kPa entering the pipe with a quality of 98%. The pipe needs to be insulated with a thermal conductivity of 0.2 W / (m K) so that the quality of the steam will only slightly decrease to 95%. The outer surface temperature of the insulation is assumed to be 25 ° C. Ignore resistance conductive of the pipe material and it is assumed that there is no pressure drop in the pipe. a. Determine the enthalpy of incoming vapor = Answer kJ / kg. b. Determine the enthalpy of steam coming out = Answer kJ / kg. c. Determine the vapor heat change / loss along the flow = Answer watt. d. Specify the minimum required insulation thickness = Answer cm.arrow_forwardA 1-in Sch 40 stainless steel pipe with a thermal conductivity of 45 W/m-K can move 1,000 kg of saturated steam per hour at 150 °C. Refractory material 0.25 inches thick with a thermal conductivity of 0.025 W/m-K insulates the pipe. At a temperature of 25 °C, the pipe is exposed to the outside air. There is a 1135 W/m2 internal heat transfer coefficient.40 W/m2-K is the outside heat transfer coefficient, whereas -K. Suppose that only the radial direction is involved in steady-state heat transfer and that radiation effects are negligible. ✓ Determine how much heat is being lost through these pipes to the environment.a. 399.1 W/mb. 1525.0 W/mc. 618.4 W/md. 1128.7 W/me. none of the above √ How about the insulated pipe's surface temperature?a. 118.5 °Cb. None of the abovec. 101.5 °Cd. 216.3 °Ce. 292.2 °Carrow_forward
- A 0.5-ampere current is flowing through a long electrically conducting cylindrical rod. The diameter of the rod is 6 mm, the electrical resistance of the rod is R = 2000 /m, and k =0.9 W/m K for the rod. The rod is encased in a 2-mm thick Pyrex tube and a 20°C liquid is flowing over the outer surface of the Pyrex tube. The convection heat transfer coefficient for the liquid h= 800 W/m2 . K. The interfacial conductance (contact resistance) at the interface between the rod and the Pyrex tube is h = 1200 W/m² - K. a) Compute the rate of heat generation in the rod and use it compute the volumetric rate of heat generation. b) Find the temperature drop across the interface between the outer surface of the rod and the inner surface of the Pyrex tube. c) Find the temperature at the center of the rod.arrow_forwardA steam is flowing through a 5.7 m long of steel tube that has inner and outer radii of r, = 0.015 and r, 0,024 m, and a thermal conductivity of 0.14 W/m.K. The steam and the outer surface of the tube is maintained at constant temperature of 150 °C and the air = 25 °C, h = 0.35 W/m2.k) is surrounding the tube. To prevent the outer surface of the steel from the environmental conditions, a material that has a thermal conductivity of 0.014 W/m.k is wrapped over the outer surface of the steel. What is the maximum heat transfer from the steam to the air (W)? NOTE: Enter your answer. Answer Air Th Steam Steel Tr 111 Toarrow_forwardConsider a large plane wall of thickness L = 0.4 m, thermal conductivity k=2.3 W/m °C,and surface area A= 20 m2. The left side of the wall at x= 0 is subjected of T1 = 80 C. while the right side losses heated by convection to the surrounding air at Too=15 C with a heat transfer coefficient of h=24 W/m2 .C. Assuming constant thermal conductivity and no heat generation in the wall, (a) express the differential equation and the boundary conditions for steady one-dimensional heat conduction through the wall, (b) obtain a relation for the variation of temperature in the wall by solving the differential equation, and (c) evaluate the rate of heat transfer through the wallarrow_forward
- A Spherical Container Is Made Of Plastic (K=2 W/MK, Ρ=5000 Kg/M) And Has Inner And Outer Radii Of 10 Cm And 11 Cm, Respectively. Hot Oil (C=3000 J/KgK, Ρ=800 Kg/M3) At 80 0C Is Stored Within The Container And The Heat Transfer Coefficient Between The Oil And The Inner Surface Of The Container H=30W/M2K The Outer Surface Of The Container IsThis problem has been solved! See the answerA spherical container is made of plastic (k=2 W/mK, ρ=5000 kg/m) and has inner and outer radii of 10 cm and 11 cm, respectively. Hot oil (c=3000 J/kgK, ρ=800 kg/m3) at 80 0C is stored within the container and the heat transfer coefficient between the oil and the inner surface of the container h=30W/m2K The outer surface of the container is perfectly insulated. Solve the differential equation under the boundary conditions for steady one dimensional heat conduction through the plastic material. a)obtain an equation fort he variation of temperature within the plastic material? b) Calculate the temperature of…arrow_forwardA pipe 30 m long with an outer diameter of 75 mm is used to deliver steam at a rate of 2000 kg / hour. The vapor pressure is 198.53 kPa entering the pipe with a quality of 98%. The pipe needs to be insulated with a thermal conductivity of 0.2 W / (m K) so that the quality of the steam will only slightly decrease to 95%. The outer surface temperature of the insulation is assumed to be 25 ° C. Ignore resistance conductive of the pipe material and it is assumed that there is no pressure drop in the pipe. a. Determine the enthalpy of incoming vapor = AnswerkJ / kg. b. Determine the enthalpy of steam coming out = AnswerkJ / kg. c. Determine the vapor heat change / loss along the flow = Answerwatt. d. Specify the minimum required insulation thickness = Answercm.arrow_forwardA cold storage wall, whose components and dimensions are given below, is formed by connecting layers A, B, C, D, E and F in series and in parallel. The temperature of the outside air is 30 oC and the temperature of the inside of the warehouse is -4 oC. If the film heat transfer coefficient between the air in the warehouse and the E layer is 24 W/m2 oC and the film heat transfer coefficient between the outer surface of the flat wall (A and F layers surface) and the atmospheric air is 16 W/m2 oC; Calculate the heat transferred in a day. (KA= 0.17 W/m.K, kc 0.98 W/m.K) (kD= 0.21 W/m.K, KF= 0.58 W/m.K) XA=3cm B KBK= 0.024 W/m.K, KE=0.01 W/m.K, F C D E XB=14 cm Xc=Xp=8cm XE=10cm AF AC AD= A/3 h= 2 m 70 cmarrow_forward
- Principles of Heat Transfer (Activate Learning wi...Mechanical EngineeringISBN:9781305387102Author:Kreith, Frank; Manglik, Raj M.Publisher:Cengage Learning