An engineer designed a double pipe heat exchanger where the hot fluid (c,=2400 J/kg.K) enters at a temperature of 100 °C with a flowrate of O.1 kg/s and is wanted to leave at a temperature of 60 °C. On the other hand, the cold fluid (c,=1200 J/kg.K) enters the heat exchanger at a temperature of 30 °C with a flowrate of 0.2 kg/s and is wanted to be heated up to 70 °C. Show that whether this design is realistic or not. If yes, what is the flow configuration (i.e. counter or parallel flow)?

An engineer designed a double pipe heat exchanger where the hot fluid (c,=2400 J/kg.K) enters at a temperature of 100 °C with a flowrate of O.1 kg/s and is wanted to leave at a temperature of 60 °C. On the other hand, the cold fluid (c,=1200 J/kg.K) enters the heat exchanger at a temperature of 30 °C with a flowrate of 0.2 kg/s and is wanted to be heated up to 70 °C. Show that whether this design is realistic or not. If yes, what is the flow configuration (i.e. counter or parallel flow)?

Principles of Heat Transfer (Activate Learning with these NEW titles from Engineering!)

8th Edition

ISBN:9781305387102

Author:Kreith, Frank; Manglik, Raj M.

Publisher:Kreith, Frank; Manglik, Raj M.

Chapter7: Forced Convection Inside Tubes And Ducts

Section: Chapter Questions

Problem 7.14P

See similar textbooks

Similar questions

10.1 In a heat exchanger, as shown in the accompanying figure, air flows over brass tubes of 1.8-cm 1D and 2.1-cm OD containing steam. The convection heat transfer coefficients on the air and steam sides of the tubes are , respectively. Calculate the overall heal transfer coefficient for the heal exchanger (a) based on the inner tube area and (b) based on the outer tube area.
In a countercurrent double-pipe heat exchanger, the hot oil entering the inner tube at 420 K with a flow rate of 60 g/s is required to be cooled to 320 K. In the space between the outer tube and the inner tube of the heat exchanger, cooling water flows at the same linear speed as the oil. Cooling water enters the heat exchanger at 290 K. The inner tube inner diameter of the heat exchanger is 25 mm and the outer tube inner diameter is 40 mm. Calculate the length of the heat exchanger. The oil side heat transfer coefficient is 1.6 kW/m2 K, and the water side heat transfer coefficient is 3.6 kW/m2 K. The densities of oil and water can be taken as 0.8 and 1.0 g/cm3, respectively, and the specific heats of oil and water can be taken as 2.0 and 4.2 kJ/kg K, respectively. Wall effects can be neglected. Flow cross-sectional area = (PI)*D2 /4 F2
In an heat exchanger of parallel flow type, water enters at 60°C and leaves at 80°C while oil of specific gravity 0.8 enters at 250°C and leaves at 100°C. The specific heat of oil is 2.5 kJ/kg K and surrounding temperature is 300 K. Determine the loss in availability on the basis of one kg of oil flow per second.
A shell and tube heat exchanger is designed as a counter flow type. Water (cp = 4182 J/kg.oC)enters the shell side at 30 oC with a mass flow rate of 12.5 kg/s. A mass flow rate of 19.5 kg/s of engine oil (cp = 1060 J/kg.oC), enters the tube side at 300 oC. Each tube is having an inner diameter of 36 mm and a wall thickness of 2 mm, and a length of 3 m. If the heat exchanger effectiveness is60 %, calculate the following: a) The tube side surface area if the overall heat transfer coefficient is 1586 W/m2. oC,b) The number of tubes used in the heat exchanger,
The mass flow rate, specific heat, and inlet temperature of the tube-side stream in a double-pipe, parallel-flow heat exchanger are 2700 kg/h, 2.0 kJ/kg·K, and 120°C, respectively. The mass flow rate, specific heat, and inlet temperature of the other stream are 1800 kg/h, 4.2 kJ/kg·K, and 20°C, respectively. The heat transfer area and overall heat transfer coefficient are 0.50 m2 and 2.0 kW/m2·K, respectively. Find the outlet temperatures of both streams in steady operation using (a) the LMTD method and (b) the effectiveness–NTU method.
A shell and tube heat exchanger is designed as a counter flow type. Water (cp = 4182 J/kg.oC) enters the shell side at 30 oC with a mass flow rate of 12.5 kg/s. A mass flow rate of 19.5 kg/s of engine oil (cp = 1060 J/kg.o C), enters the tube side at 300 oC. Each tube is having an inner diameter of 36 mm and a wall thickness of 2 mm, and a length of 3 m. If the heat exchanger effectiveness is 60 %, calculate the following:1. The heat transfer rate,2. The exit temperature for each fluid,
A shell and tube heat exchanger is designed as a counter flow type. Water (cp = 4182 J/kg.o C)enters the shell side at 30 o C with a mass flow rate of 12.5 kg/s. A mass flow rate of 19.5 kg/s of engine oil (cp = 1060 J/kg.oC), enters the tube side at 300 oC. Each tube is having an inner diameter of 36 mm and a wall thickness of 2 mm, and a length of 3 m. If the heat exchanger effectiveness is 60 %, calculate the following: a). The temperature efficiency of the heat exchanger, andb). The capacity ratio of the heat exchanger.
0.8 kg/s of water enters the tube from a type 2 shell-pass, 4 tube-pass heat exchanger at 17˚C and leaves the tube at 37˚C. This water is used to cool the air entering the shell at a temperature of 250˚C. U=432 W/m2.˚C. Definea. The temperature of the air coming out of the heat exchangerb. The area of the heat exchanger required.c. Heat exchanger effectivenessd. After using the heat exchanger for 5 years, it occurs causing an increase in the thermal resistance value of Rf = 0.0005 m2.˚C/W. Calculate what is the temperature of the air coming out of the heat exchanger now?
2- In a heat exchanger, steam of 0.08 bar and a specific steam content of 95% is condensed. 381.6 tons / h cooling water with a temperature of 10 ̊C flows in parallel connected tubers with inner / outer diameter 28/30 mm with a speed of 0.65 m / s. The heat transfer surface of the heat exchanger is 220 m2 and it has a k-value of 2200 W / (m2K) . Assume the specific heat capacity of the water 4.18 kJ / (kg K) and density 1000 kg / m3. The K-value is attributed to the outer mantle surface of the tubes. a) Calculate the outlet temperature of cooling water. b) How many tonnes of steam per hour are condensed? c) Determine the number of tubes and tube length
A 10-m-long countercurrent-flow heat exchanger is being used to heat a liquid food from 20 to 80 C. The heating medium is oil, which enters the heat exchanger at 150 C and exits at 60 C. The specific heat of the liquid food is 3.9 kJ/(kg K). The overall heat-transfer coefficient based on the inside area is 1000 W/ (m2 K). The inner diameter of the inside pipe is 7 cm. a. Estimate the flow rate of the liquid food. b. Determine the flow rate of the liquid food if the heat exchanger is operated in a concurrent-flow mode for the same conditions of temperature at the inlet and exit from the heat exchanger.
3. In a shell-and-tube heat exchanger, water enters at 85°C at the rate of 5.4 kg/s. Engine oil enters at 20°C and leaves at 60°C. The water leaves the heat exchanger at 57°C. What is the mass flow rate of the engine oil? Express your answer in kg/s.
In a single-body, four-pipe transition heat exchanger, the hot combustion product gases are cooled by water. Flow of gases 3 kg / s, specific temperature0.95 kJ / kg.°C; water flow 0.2 kg / s, specific temperature 4.2 kJ / kg.°C dir. The total heat transfer coefficient of the heat exchanger is 300 W / m2.K, heat transfer surface area is 10 m2.a) the heat transfer that occurs and the output temperatures of both fluids;b) find the logarithmic mean temperature difference.