Question 1 En. Karim recently bought a heat exchanger for his metal factory. The heat exchanger is a cross-flow type which has cross section size of 1 m X 1 m. En. Karim assigned you to calculate the effectiveness of the heat exchanger. As an engineer, you decided to do the analysis based on section by section. One section of the heat exchanger duct consists 3 cm diameter of 80 tubes. Cold water (cp = 4180 J/kg.K) enters the tube at 18°C. The average velocity of the cold water is 3 m/s. Meanwhile, hot air (c, = 1010 %3D J/kg.K) enters the section at 130°C and 105 kPa. The velocity of the hot air is 12 m/s and air constant, R is 0.287 kJ/kg.K. If the overall heat transfer coefficient is 130 W/m2.K, determine i. the mass flow rates of both cold water and hot air, ii. the rate of heat transfer, iii. the effectiveness of the heat exchanger (NTU method), iv. the actual rate of heat transfer, and v. the outlet temperatures of both cold water and hot air.

Question 1 En. Karim recently bought a heat exchanger for his metal factory. The heat exchanger is a cross-flow type which has cross section size of 1 m X 1 m. En. Karim assigned you to calculate the effectiveness of the heat exchanger. As an engineer, you decided to do the analysis based on section by section. One section of the heat exchanger duct consists 3 cm diameter of 80 tubes. Cold water (cp = 4180 J/kg.K) enters the tube at 18°C. The average velocity of the cold water is 3 m/s. Meanwhile, hot air (c, = 1010 %3D J/kg.K) enters the section at 130°C and 105 kPa. The velocity of the hot air is 12 m/s and air constant, R is 0.287 kJ/kg.K. If the overall heat transfer coefficient is 130 W/m2.K, determine i. the mass flow rates of both cold water and hot air, ii. the rate of heat transfer, iii. the effectiveness of the heat exchanger (NTU method), iv. the actual rate of heat transfer, and v. the outlet temperatures of both cold water and hot air.

Elements Of Electromagnetics

7th Edition

ISBN:9780190698614

Author:Sadiku, Matthew N. O.

Publisher:Sadiku, Matthew N. O.

ChapterMA: Math Assessment

Section: Chapter Questions

Problem 1.1MA

See similar textbooks

Similar questions

FROM BOOK: ENGINEERING THERMOFLUIDS, M. MASSOUD
Hot oil is pumped through a heat exchanger (see figure below) at a flow rate of 0.5 L/s. An inlet manifold equally distributes the oil into 20 parallel, 5-mm-diameter copper tubes that are about 1 m in length. The oil cools down as it flows through the copper tubes. Oil then exits through an outlet manifold. The viscosity of the oil is 250 centipoise and its density is 950 kg/(m^3). Assuming uniform pressure in the manifolds and laminar flow through the tubes. calculate the total head loss (in meters) across those 20 copper tubes. COPPER TUBES MANIFOLDS Round your answer to 2 decimal places.
Hot oil is pumped through a heat exchanger (see figure below) at a flow rate of 0.5 L/s. An inlet manifold equally distributes the oil into 20 parallel, 5-mm-diameter copper tubes that are about 1 m in length. The oil cools down as it flows through the copper tubes. Oil then exits through an outlet manifold. The viscosity of the oil is 250 centipoise and its density is 950 kg/(m^3). Assuming uniform pressure in the manifolds and laminar flow through the tubes, calculate the total head loss (in meters) across those 20 copper tubes.
Due higher viscosity, the heat-transfer coefficient of moving liquid hydrocarbons is generally higher than that of moving water Select one: O True O False The proper strategy to enhance heat transfer of a heat exchanger is trying to increase the heat transfer coefficient of the side with the lower heat resistant. Select one: O True O False For the universal 3-D heat transfer equation (see topic 7 in URCourses notes), we have to simplify by eliminating terms that are zero or near zero first, and then we can only use numerical methods (such as finite difference) to solve those problems. Select one: O True O False
2.) A 30 ft copper pipe is 1.5 ft in diameter and has a thickness of 2 in. It has an internal temperature of 85F and an external temperature of 70F. Solve for k if the rate of heat transfer is 2.6 x 106 Btu hr
C: water flows at 50 °C inside a 2.5 cm diameter tube such that h-3500 W/m2. °C. The tube has a wall thickness of 0.8 mm with a thermal conductivity of 16 W/m.°C. The outside of the tube loses heat by convection with ho-7.6 W/m².°C. If the heat loss to the surrounding per unit length is 19 W. Calculate the surrounding air temperature.
Calculate using SI units a) the mass flow rate in pipe 1 and pipes 3
a. An air stream passing through a 2-inch (1/6 ft) diameter, thin-walled tube is to be heated by high- pressure steam condensing on the outer surface of the tube at 320 °F. The overall heat transfer coefficient, h between steam and air can be assumed to be 25 Btu/(ft2.hr °F) with the air entering at 100 ft/sec, 10 psia, 40 °F. The air is to be heated to 150 °F. Determine the tube length required. Assuming Rayleigh Line flow, calculate the static pressure change due to heat addition. Also, for the same inlet conditions, calculate the pressure drop due to friction, assuming Fanno flow in the duct with f = 0.018. b. c. d. To obtain an approximation to the overall pressure drop in this heat exchanger, add the two results. Discuss the accuracy of this calculation.
G. ?" Which matcrial has the higher themal conductivity'? d: 5. (ht What is the overall heat-transfer coefficicnt U? Describe a physical situation,in す 5コ . :- which it could be used. 石:.5 . (c) A standard Schedule 405 cm steel pipe (inside diameter 5.25 cm and wall thickness 040 cm) čarrying steam is lagged (i.e insulated) with 5.0 cm of 85 per cent magnesia covered in turn with 5.0 cm of cork. Estimate the heat loss per hour per meter of pipc if the inner surface of the pipe is at 120°C and the outer surface of the cork is at 32°C. The thermal conductivitics of the substances concerned are 9. of Material Thermal Conductivity [Watts/ha K] Steel 45 85% Magnesia (0.07 Cork 0.05 At いい 1
i need the answer quickly
01: A- A large hydropower station has a head of 50 m. The rated power of plant installed is 200 MW. Find: 1- The yearly average flow of water in the penstock to make the yearly capacity factor of this plant is CF% where CF value is the last two digits (from right) of your registration number (i.e. for the student that has a registration number 202112396, CF =96). The efficiencies of the penstock, hydro turbine and the electrical generator are 97%, 92%, 93% respectively. 2- What is the amount of water required to be yearly stored to achieve this generation. 3- Suggest a way to increase this capacity factor. Verify your answer.
Q1) Find the heat transfer rate through a plane wall 20cm thick and 0.1m2 heat transfer area. The temperatures across the wall are 100 "C and 10 C respectively and the thermal conductivity is varies according to the equation (k = 60(1+0.03T)).