What effect do finned surfaces have on the overall heat transfer coefficient and hence the performance of a heat exchanger? When is the use of fins most appropriate
Q: Hot oil (cp = 2200 J/kg·K) is to be cooled by water (cp = 4180 J/kg·K) in a 2-shell-passes and…
A: Given data: Specific heat of water, Cpc = 4180 J/kg Mass flow rate of water, mc = 0.1 kg/s Specific…
Q: Explain in detail the phenomenon and concept of the heat transfer involved in the heat exchanger and…
A: Heat exchanger is a device that is used to transfer heat between two fluids. An important aspect of…
Q: A counter-flow heat exchanger is stated to have an overall heat transfer coefficient, based on…
A: Given data: When operating under clean conditions, Uclean = 50 Btu/h·ft2·°F Fouling factor, Rf =…
Q: A 1-shell-pass and 8-tube-passes heat exchanger is used to heat glycerin (cp = 0.60 Btu/lbm·°F) from…
A: Given data as per question No. of tubes = 8 cp of glycerin= 0.60 Btu/lbm·°F Diameter = 0.5 in…
Q: A heat exchanger that is used for cooling lubricating oil is comprised of a thin-walled inner tube…
A: Diameter of inner tube, d1=30 mm=0.030 mDiameter of outer tube, d2=50 mm=0.050 mOverall heat…
Q: What effect do finned surfaces have on the overall heat transfer coefficientand hence the…
A: Hello. Since you have posted multiple questions and not specified which question needs to be solved,…
Q: Oil in an engine is being cooled by air in a crossflow heat exchanger, where both fluids are…
A: Given, The specific heat of the oil, cp,h = 2047 J/kgK The specific heat of the air, cp,c = 1007…
Q: In the heat transfer relation Q= UAs DTlm for a heat exchanger, what is DTlm called? How is it…
A: Heat exchanger is a steady flow adiabatic open system in which two flowing fluids exchange or…
Q: Water with a flow rate of 225 kg / h and a specific temperature of 4188 J / kgK is heated by a…
A: Given data: Mass flow rate of water, m˙w=225 kg/hr and it's specific heat, Cw=4188 kJ/kg.K.…
Q: Explain how the LMTD method can be used to determine the heat transfer surface area of a multipass…
A: Cross Flow heat exchanger: In this type of heat exchanger hot and cold fluid travel in…
Q: uestion 2.1.3.1: What advantage does the effectiveness-NTU method have over the LMTD method. What…
A: The LMTD method is used for obtaining the rate of the heat transfer through the heat exchanger when…
Q: (1) In a double tube heat exchanger in which hot and cold fluids flow into a countercurrent flow,…
A: We will answer the first question since the exact one is not specified. Please resubmit the question…
Q: Consider a concentric tube heat exchanger with an area of 50 m² operating under the following…
A:
Q: Fins are usually used in to increase the surface area of the heat exchanger so that it increases the…
A: Given: b = 2 mm tolerance =0.05 mm L = 1.5cm To find: Heat transfer area
Q: Hot water at 90°C flows on the inside of a 2.5-cm-ID steel tube with 0.8-mm wall thickness at a…
A:
Q: 1. An oil heater heats 100 kg per minute of oil from 30°C to 100°C in a counter-flow heat exchanger.…
A:
Q: a) Calculate the log-mean-temperature difference and value of overall heat transfer coefficient from…
A:
Q: The temperature difference between the hot and cold fluids in a heat exchanger is given to be ∆? at…
A: The symbols representing the temperature difference in the hot and cold fluids at each end are not…
Q: Hot water at 60°C is cooled to 36°C through the tube side of a one-shell pass and two-tube passes…
A: It is required to determine the logarithmic mean temperature difference for counter flow. The…
Q: Define the NTU, EFFECTIVENESS and CAPACITY RATIO in a heat exchanger and also tell what each depicts…
A: NTU ( Number of transfer units):-NTU is used for heat transfer in heat exchanger and formula for the…
Q: A double-pipe heat exchanger is constructed of a copper (k = 380 W/m-°C) inner tube of internal…
A:
Q: Concentric Tube Heat Exchanger List at least two assumptions that are being made in the heat…
A: TO DETERMINE :- (a) two assumptions, (b) reasons for the assumptions taken.
Q: What is application of parallel flow heat exchanger? and counter flow heat exchanger?
A:
Q: Q#1: Discuss the significant and industrial application of heat transfer from extended surface…
A: Since we only answer one question at a time, we will answer the first one. Please resubmit the…
Q: 3. An oil heater heats 100 kg per minute of oil from 30°C to 100°C in a counter-flow heat exchanger.…
A:
Q: A long thin-walled double-pipe heat exchanger with tube and shell diameters of 1.0 cm and 2.5 cm,…
A: Given data: The diameter of tube heat exchanger is: Do=1 cm =0.01 m The diameter of shell haet…
Q: Determine the length needed for a simple concentric-tube, parallel flow heat exchanger to transfer…
A: Rate of heat transfer from hot water to cold water, Q=900 WThermal conductivity of copper tube,…
Q: Under what conditions will the temperature rise of the cold fluid in a heat exchanger be equal to…
A: Heat capacity: It is the product of the mass flow rate of the fluid with the specific heat capacity.…
Q: What are mixed and unmixed flow heat exchangers? Explain with the help of an example
A: Heat exchanger: The heat exchanger is a device used to exchange the heat from one fluid to another…
Q: Calculate the rate of overall heat transfer coefficient for the tube heat exchanger with inner and…
A: Calculated overall heat transfer coefficient. And the rate of heat transfer per meter length of the…
Q: A counter-flow heat exchanger is stated to have an overall heat transfer coefficient of 284 W/m2·K…
A: Given data as per question Overall heat transfer coefficient = 284 W/m2·K Hot fluid entry…
Q: Saturated water vapor at 100°C condenses in the shell side of a one-shell and two-tube heat…
A: Given data as per question water vapor temperature =100°C Surface area = 0.5 m2 Overall heat…
Q: a) Why the use of shell and tube heat exchanger is more compared to other heat exchangers? b) What…
A: Solution:
Q: What effect do finned surfaces have on the overall heat transfer coefficientand hence the…
A: Fin: It is a extended surface from the hot surface to increase the heat transfer area.
Q: How does a cross-flow heat exchanger differ from a counter-flow one? What is the difference between…
A: Counter flow heat exchanger Cross flow heat exchanger Counter flow heat exchanger Cross flow…
Q: The condenser of a large thermal power plant is a body-tube type heat exchanger consisting of a…
A: Given Convection coefficient, h = 11000 W / m2K Mass flow rate, m =30000 kg / h…
Q: A heat exchanger has an over-all coefficient of heat transfer of 900 W/m2-K. The mean temperature…
A: Given Data: The overall coefficient of heat transfer, U=900 W/m2-K Heat loss, Q=15000 W
Q: What are mixed and unmixed flow heat exchangers? Explain with the help of an example.
A: Heat exchangers are the devices that are used for exchanging the heat from one liquid to another…
Q: Your second customer wants to choose a parallel-flow-plate-type heat exchanger that contains two…
A: Given data: The heat transfer coefficient of water is hw=1200 W/m2°C The heat transfer coefficient…
Q: Why does a “mixed” or “unmixed” fluid arrangement influence heat-exchanger performance? with…
A: Mixing of the fluid provides better performance due to the direct energy transmission of the heat…
Q: Why does a “mixed” or “unmixed” fluid arrangement influence heat-exchanger performance?
A: Given: Why does a “mixed” or “unmixed” fluid arrangement influence heat-exchanger performance?
Q: Write down the total thermal resistance for a double-pipe heat exchanger. Show how to convert from…
A: Explain how flow regime may affect overall heat transfer rate
Q: Water enters at 20 °C at a rate of 0.1 kg/s in a double-pipe counter flow heat exchanger is to be…
A:
Q: For specified inlet and outlet temperatures, for what kind of heat exchanger will the DTlm be…
A: The device which is used to transfer the heat from one another medium is called as heat exchanger.…
Q: How would you formulate this problem to obtain a more meaningful result which desired to cool a gas…
A: Given: Cp of gas = 0.35Btu/lb F Temperature of hot fluid in (Thi)=190F Temperature of hot fluid out…
Q: Show that the temperature profile of two fluid streams (hot and cold) that have the same heat…
A:
Q: What are the common approximations made in the analysis of heat exchangers?
A: The common approximations given that made during the analysis of heat exchangers, (1) The heat…
Q: (c) i) Calculate the tube-side convective heat transfer coefficient (h) if the heat exchanger has…
A: Write the given data with suitable variables.
Q: A long thin-walled double-pipe heat exchanger with tube and shell diameters of 1.0 cm and 2.5 cm,…
A: Given data d1=1 cmd2=2.5 cmh1=4100 W/m2Kk=0.6 W/m°CPr=7.01 Here, d is the diameter and k is the…
Heat Exchangers
Heat exchangers are the types of equipment that are primarily employed to transfer the thermal energy from one fluid to another, provided that one of the fluids should be at a higher thermal energy content than the other fluid.
Heat Exchanger
The heat exchanger is a combination of two words ''Heat'' and ''Exchanger''. It is a mechanical device that is used to exchange heat energy between two fluids.
What effect do finned surfaces have on the overall heat transfer coefficient and hence the performance of a heat exchanger? When is the use of fins most appropriate
Step by step
Solved in 2 steps
- Determine the rate of heat transfer per meter length to a light oil flowing through a 2.5-cm-ID, 60-cm-long copper tube at a velocity of 0.03 m/s. The oil enters the tube at 16C, and the tube is heated by steam condensing on its outer surface at atmospheric pressure with a heat transfer coefficient of 11.3 kW/m K. The properties of the oil at various temperatures are listed in the following table: Temperature, T(C) 15 30 40 65 100 (kg/m3) 912 912 896 880 864 c(kJ/kgK) 1.80 1.84 1.925 2.0 2.135 k(W/mK) 0.133 0.133 0.131 0.129 0.128 (kg/ms) 0.089 0.0414 0.023 0.00786 0.0033 Pr 1204 573 338 122 55Question 3.1:Whatt effect do finned surfaces have on the overall heat transfer coefficient and hence the performance of a heat exchanger? When is the use of fins most appropriate? (Determine the length needed for a simple concentric-tube, parallel flow heat exchanger to transfer heat from hot water to cold water at a rate of 900 W. The heat exchanger consists of two Type K copper (k=386 W/m-degC) tubes. The smaller tube has an inside diameter of 49.8 mm and an outside diameter of 54.0 mm. Assume that both film coefficients are equal to 100 W/sq.m.-degC. The hot water enters at 90 degC and leaves at 50 degC, and the cold water enters at 10 degC and leaves at 40 degC.
- What effect do finned surfaces have on the overall heat transfer coefficientand hence the performance of a heat exchanger? When is the use of fins mostappropriate?a one shell and two tube pass heat exchanger, coolant enters the tube at 4.81 kg/s (spread over 72 tubes with each tube being 0.01 m in diameter and 1.95 m length) at an initial temperature of 25 C. Water enters the shell at 2.5 kg/s at an initial temperature of 5 C. The average convection coefficient of the water is known to be 1e4 W/m2.K. What is the overall heat transfer coefficient, assuming no fouling, negligible tube thermal resistance and near-identical inner and outer tube surfaces? What is the actual heat transfer rate? What is the coolant outlet temperature? The coolant properties are Cp = 1040 J/kg.K, μ = 7.65e-4 kg/s.m, k = 0.058 W/m.K and Pr = 14. Assume the water Cp = 4200 J/kg.K.Calculate the rate of overall heat transfer coefficient for the tube heat exchanger withinner and outer heat transfer coefficient of 670 W/m2 -K and 1880 W/m2 -K, respectively.Thermal conductivity of the tube wall is 27 W/m-K. The diameter and the thickness of thetube are 4 cm and 1.5 mm, respectively. Then, calculate the rate of heat transfer for the tube heatexchanger per meter length if the temperatures of inner and outer surfaces are 100°Cand 52°C, respectively.
- A long thin-walled double-pipe heat exchanger with tube and shell diameters of 2 cm and 4 cm, respectively, is used to condense refrigerant-134a by water at 20 C. The refrigerant flows through the tube, with a convection heat transfer coefficient of hi = 4000 W/m2 K.A 1-mm-thick layer of limestone (k = 1.2 W/mK) forms on the outer surface of the inner tube. Water flows through the shell at a rate of 0.4 kg/s. Determine the overall heat transfer coefficient U of this heat exchanger with and without the fouling factor, and the error in U introduced by neglecting the fouling factor. Comment the fouling effect on this heat exchanger.A refrigerant 22 condenser has four water passes and a total of 60 copper tubes that are 14 mm ID and have 2 mm wall thickness. The conductivity of copper is 3 90 W/m • K. The outside of the tubes is finned so that the ratio of outside to inside area is 1.7. The cooling-water flow through the condenser tubes is 3.8 L/s (a) Calculate the water-side coefficient if the water is at an average temperature of 30°C, at which temperature k = 0.614 W/m • K, p = 996 kg/m3 , andµ= 0.000803 Pa• s (b) Using a mean condensing coefficient of 1420 W/m2 • K, calculate the overall heat-transfer coefficient based on the condensing area.How is the NTU of a heat exchanger defined? What does it represent? Is a heat exchanger with a very large NTU (say, 10) necessarily a good one to buy?
- A double-pipe heat exchanger is constructed of a copper (k = 380 W/m-°C) inner tube of internal diameter D; = 1.2 cm and external diameter D, = 1.6 cm and an outer tube of diameter 3.0 cm. The convection heat transfer coefficient is reported to be h; = 700 W/m2°C on the inner surface of the tube and h, = 1400 W/m2°C on its outer surface. For a fouling factor Rf; = 0.0005 m2°CW on the tube side and Rio = 0.0002 m2°C/W on the shell side, determine the thermal resistance of the heat exchanger per unit length.Fill in the blanks: A double-pipe heat exchanger is constructed of a copper (k = 380 W/m-°C) inner tube of internal diameter D; = 1.2 cm and external diameter D, = 1.6 cm and an outer tube of diameter 3.0 cm. The convection heat transfer coefficient is reported to be h; = 700 W/m4-°C on the inner surface of the tube and ho = 1400 W/m-C on its outer surface. For a fouling factor Re = 0.0005 m2.°C/W on the tube side and Rfo = 0.0002 m2-°C/W on the shell side, determine the overall heat transfer coefficient based on the inner surface area of the tube. W/m2KA 2-shell passes and 4-tube passes heat exchanger is used to heat glycerin from 20°C to 50°C by hot water, which enters the thin-walled 2-cm-diameter tubes at 80°C and leaves at 40°C (Fig. 13-21). The total length of the tubes in the heat exchanger is 60 m. The convection heat transfer coefficient is 25 W/m2 . °C on the glycerin (shell) side and 160 W/m2. °C on the water (tube) side. De- termine the rate of heat transfer in the heat exchanger (a) before any fouling oc- curs and (b) after fouling with a fouling factor of 0.0006 m2 . °C/W occurs on the outer surfaces of the tubes.