In order to cool a mass flow rate of 25 Kg/h of air (cp = 1060 J/Kg oC)  at 300 oC, it is passed through the tube side of a counter flow heat exchanger with a length of 2 m and 2.54 cm tube outer diameter. The cooling water, (cp = 4182 J/Kg oC and  r  = 1000 Kg/m3), enters the heat exchanger at a temperature of 30 oC with a volume flow rate of 0.3 Litre/min. If the overall heat transfer coefficient, U, is 5.83 W/m2 oC and the effectiveness of the heat exchanger 60 %, calculate the following: The heat transfer rate, The exit temperatures of both the water and the air, The surface area of the heat exchanger, The number of tubes used in the heat exchanger The capacity rate ratio.

A thin-walled double-pipe, counter-flow heat exchanger is to be used to cool oil (cp = 0.525 Btu/lbm·°F) from 300°F to 105°F at a rate of 5 lbm/s by water (cp = 1.0 Btu/lbm·°F) that enters at 70°F at a rate of 3 lbm/s. The diameter of the tube is 5 in and its length is 200 ft. Determine the overall heat transfer coefficient of this heat exchanger using (a) the LMTD method and (b) the «-NTU method.

Hot exhaust gases of a stationary diesel engine are to be used to generate steam in an evaporator. Exhaust gases (cp = 1051 J/kg·K) enter the heat exchanger at 550°C at a rate of 0.25 kg/s while water enters as saturated liquid and evaporates at 200°C (hfg = 1941 kJ/kg). The heat transfer surface area of the heat exchanger based on water side is 0.5 m2 and overall heat transfer coefficient is 1780 W/m2·K. Determine the rate of heat transfer, the exit temperature of exhaust gases, and the rate of evaporation of water.

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In order to cool a mass flow rate of 55 Kg/h of air (cp = 1060 J/KgoC) at 300o C, it is passed through the tube side of a counter flow heat exchanger with a length of 2 m and 2.54 cm tube outer diameter. Thecooling water, (cp = 4182 J/Kg o C and ρ = 1000 Kg/m3 ), enters the heat exchanger at a temperature of 30o  C with a volume flow rate of 0.6 Litre/min. If the overall heat transfer coefficient, U, is 5.83 W/m2oC andthe effectiveness of the heat exchanger 60 %, calculate the following:a. The heat transfer rate,b. The exit temperatures of both the water and the air,c- The surface area of the heat exchanger,

A shell-and-tube heat exchanger is used for cooling 47 kg/s of a process stream flowing through the tubes from 160°C to 100°C. This heat exchanger has a total of 100 identical tubes, each with an inside diameter of 2.5 cm and negligible wall thickness. The average properties of the process stream are r = 950 kg/m3, k = 0.50 W/m·K, cp = 3.5 kJ/kg·K and m = 2.0 mPa·s. The coolant stream is water (cp = 4.18 kJ/kg·K) at a flow rate of 66 kg/s and an inlet temperature of 10°C, which yields an average shellside heat transfer coefficient of 4.0 kW/m2·K. Calculate the tube length if the heat exchanger has (a) a one-shell pass and a one-tube pass and (b) a one-shell pass and four-tube passes.

Consider a shell-and-tube water-to-water heat exchanger with identical mass flow rates for both the hot- and cold-water streams. Now the mass flow rate of the cold water is reduced by half. Will the effectiveness of this heat exchanger increase, decrease, or remain the same as a result of this modification? Explain. Assume the overall heat transfer coefficient and the inlet temperatures remain the same.

A shell-and-tube process heater is to be selected to heat water (cp = 4190 J/kg.K) from 20°C to 90°C by steam flowing on the shell side. The heat transfer load of the heater is 600 kW. If the inner diameter of the tubes is 1 cm and the velocity of water is not to exceed 3 m/s, determine how many tubes need to be used in the heat exchanger.

Water enters at 20 ℃ at a rate of 0.2 kg/s in a double-pipe parallel flow heat exchanger is to be heated to 70 ℃ by geothermal water that enters the heat exchanger at 155 ℃ at a rate of 0.3 kg/s. The overall heat transfer coefficient of the heat exchanger is 500 W/m2. ℃. The internal diameter of the tube is 1.2 cm. Determine the length of the heat exchanger. The specific heats of the water and geothermal water are given to be 4.18 and 4.31 kJ/kg.℃, respectively. Select one: a. 25.4 m b. 30.5 m c. 20.7 m d. 27.5 m

A stream of ammonia is cooled from 100oC to 20oC at a rate of 180 kg/hr in the tube side of a double-pipe counter-flow heat exchanger. Water enters the heat exchanger at 10oC at a rate of 250 kg/hr. The outside diameter of the inner tube is 3 cm and the length of the pipe is 7m. Using the log-mean temperature difference, calculate the overall heat transfer coefficient (U) for the heat exchanger. Determine the log-mean temperature difference. Determine the heat transfer coefficient for the heat exchanger.   Cp for ammonia is 5234J/kgK and cp for water is 4180J/kgK.