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A steel tube
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Fundamentals of Heat and Mass Transfer
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- A steam power plant is equipped with a condenser that removes 500 MW of heat from steam condensing at 30°C. The tubes of the heat exchanger have an internal diameter of 2 cm, and the overall heat transfer coefficient is 3500 W/m2 · °C. The cooling is provided by cooling water from a surrounding river, which enters the tubes at 18°C and leaves at 26°C. Determine the heat transfer surface area in m2.arrow_forwardA water-to-water double pipe heat exchanger is required to cool down 4200 kg/h hot process water from 120°C to 80°C. Available for this purpose is 3800 kg/h cold water at 30°C. The inner pipe inside diameter is 2.7 cm while outside diameter of the inner pipe is 3.3 cm. If the overall heat transfer coefficient is 580 W/(m2·K), calculate the length of the heat exchanger required to achieve the desired heating. Use heat capacity of water as 4.2 J/(g·K) for both streams.arrow_forwardCalculate the overall heat transfer coefficient of the steel pipe based on the inner surface. The inner diameter of the pipe is 12.7 cm, and the thickness of the pipe is 2.4 cm. The convective heat transfer coefficient in the pipe is 350 W / (m² °C), the convective heat transfer coefficient outside the pipe is 25 W / (m² °C), the thermal conductivity of the steel pipe is 15 W / (m °C) . If a pipe is used to deliver steam at 110 °C and the ambient temperature is 30 °C, determine the rate of heat transfer from the pipe per meter. q = AnswerWatts/marrow_forward
- (1)aA double pipe heat exchanger is constructed of a copper (k=380Wm.K) inner tube of internal diameter D1=1.2cm and external diameter D0=1.6cm and an outer tube diameter 3.0cm.The convection heat transfer coefficient is reported to be hi=700W/m2.K on the inner surface of the tube and h0 =1400W/m2.K on its outer surface.For a fouling factor Rf,I=0.0005m2.K/W on the tube side and Rf,o=0.0002m2.K/W on the shell side, determine (I) the thermal resistance of the heat exchanger per unit length.(ii) the overall heat transfer coefficients Ui and U0 base on the inner and outer surface area of the tube, respectively. (b)Classify heat exchangers according to the flow type and explain the characteristics of each type. (c)How does the presence of baffles affect the heat transfer and the pumping power requirements? Explain (d) Consider a hot baked potato.Will the potato cool faster or slower when we blow the warm air coming from our lungs on it instead of letting it cool naturally in the cooler…arrow_forwardThe condenser of a room air conditioner is designed to reject heat at a rate of 15,000 kJ/h from refrigerant-134a as the refrigerant is condensed at a temperature of 40°C. Air (cp = 1005 J/kg·K) flows across the finned condenser coils, entering at 25°C and leaving at 35°C. If the overall heat transfer coefficient based on the refrigerant side is 150 W/ m2·K, determine the heat transfer area on the refrigerant side.arrow_forward3. A 6 in x 20 ft uninsulated B.I pipe conveys steam at 385 °F with an average ambient temperature of 85°F. if the cost of the fuel is PhP 250.00 per 106 BTU with the net energy conversion efficiency of 75%, what is the annual cost of the heat lost? For 6 in. pipe schedule 80:Do = 6.625 inDi = 5.761 in For iron:k = 30 BTU/ hr ft °F for the surface coefficients:hi = 1000BTU/ hr ft2°F ho = 2 BTU/hr ft2 °Farrow_forward
- A counterflow bank of boiler tubes has a total area of 900 ft^2 and its overall efficiency of heat transfer is 13 Btu/hr-ft-°F. Calculate the heat transferred if the log mean temperature difference is 1380°F.arrow_forwardA room is cooled by circulating chilled water through a heat exchanger located in the room. The air is circulated through the heat exchanger by a 0.25-hp (shaft output) fan. Typical efficiency of small electric motors driving 0.25-hp equipment is 60 percent. Determine the rate of heat supply by the fan–motor assembly to the room.arrow_forward2- 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 lengtharrow_forward
- A double tube heat exchanger is made of copper (k = 380 W / m. ° C). Inner diameter of inner tube Di = 1.2 cm, outerits diameter is D0 = 1.6 cm and the diameter of the outer pipe is 3.0 cm. Convection heat transfer coefficient on the inner surface of the pipehigh = 700 W / m2. ° C and the heat transfer coefficient on the outer surface h0 = 1400 W / m2. ° C. Pipe sidecontamination factor Rf, i = 0.0005 m2. ° C / W and fouling factor Rf on the body side, 0 = 0.0002 m2. ° C / WAccording to the example; Calculate the thermal resistance of the heat exchanger per unit length.arrow_forwardA double tube heat exchanger is made of copper (k = 380 W / m. ° C). Inner diameter of inner tube Di = 1.2 cm, outerits diameter is D0 = 1.6 cm and the diameter of the outer pipe is 3.0 cm. Convection heat transfer coefficient on the inner surface of the pipehigh = 700 W / m2. ° C and the heat transfer coefficient on the outer surface h0 = 1400 W / m2. ° C. Pipe sidecontamination factor Rf, i = 0.0005 m2. ° C / W and fouling factor Rf on the body side, 0 = 0.0002 m2. ° C / WAccording to the example; Total heat transfer coefficients (U0 and Ui), taking into account the inner and outer surface areas of the pipecalculate.arrow_forwardIn an industrial facility a counter-flow double-pipe heat exchanger uses superheated steam at a temperature of 250°C to heat feed water at 30°C. The superheated steam experiences a temperature drop of 70°C as it exits the heat exchanger. The water to be heated flows through the heat exchanger tube of negligible thickness at a constant rate of 3.47 kg/s. The convective heat transfer coefficient on the superheated steam and water side is 850 W/m2·K and 1250 W/m2·K, respectively. To account for the fouling due to chemical impurities that might be present in the feed water, use an appropriate fouling factor for the water side. Determine (a) the heat exchanger area required to maintain the exit temperature of the water to a minimum of 70°C, and (b) what would be the required heat exchanger area in case of parallel flow arrangement?arrow_forward
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