An automobile radiator may be viewed as a cross-flow heat exchanger with both fluids unmixed. Water,...
An automobile radiator may be viewed as a cross-flow heat exchanger with both fluids unmixed. Water, which has a flow rate of 0.045 kg/s, enters the radiator at 400 K and is to leave at 330 K. The water is cooled by air that enters at 0.75 kg/s and 300 K. If the overall heat transfer coefficient is 220 W/m2.K, what is the required heat transfer surface area, in mº? Assume that T =320 K when evaluating the properties of...
4. A Cross-Flow Air-to-Water Heat Exchanger with an effectiveness of 0.58 is used to heat water, entering at 20°C at a rate of 4 kg/s, using hot air, entering at 127oC at a rate of 10 kg/s. The Overall Heat Transfer Coefficient for the Heat exchanger is 275 W/m'K. Assuming both fluids are unmixed, determine; (i) The Heat Capacity rates for both the air and the water (ii) The heat transfer surface area. ii) The exit temperature of the water...
10-58) An air preheater for a power plant consists of a cross-flow heat exchanger with hot exhaust gases used to heat incoming air at I atm and 300 K. The gases enter at 375°C with a flow rate of 5 kg/s. The airflow rate is 5.0 kg/s, and the heat exchanger has A = 110 m2 and U = 50 W/m2 oC. Calculate the heat-transfer rate and exit temperatures for two cases, both fluids unmixed and one fluid mixed. Assume...
Question 1- Exhaust gases from a power plant are used to preheat air in a cross-flow heat exchanger. The exhaust gases enter the heat exchanger at 450°C and leave at 200°C. The air enters the heat exchanger at 70°C, leaves at 250°C, and has a mass flow rate of 10 kg/s. Assume the properties of the exhaust gases can be approximated by those of air. The overall heat transfer coefficient of the heat exchanger is 154 W/m2 K. Calculate the...
please do 11.33 11.32 A single-pass, cross-flow heat exchanger uses hot exhaust gases (mixed) to heat water (unmixed) from 30 to 80°C at a rate of 3 kg/s. The exhaust gases, hav- ing thermophysical properties similar to air, enter and exit the exchanger at 225 and 100°C, respectively. If the overall heat transfer coefficient is 200 W/m2.K, estimate the required surface area. 11.33 Consider the fluid conditions and overall heat transfer coefficient of Problem 11.32 for a concentric tube heat...
a radiator uses air to cool ethylene glycol (antifreeze) in a cross flow heat exchanger the ethylene glycol(cp= 0.678) enters the radiator, as shown in figure 1 below, at 150 f with a flow rate of 5 ibm/s. it leaves the radiator at 80 f. air at 70 f blows over the radiator at a flow rate of 10000 cfm determine (a) the heat lost by the antifreeze , (b) the mass flow rate of the air in ibm/s and...
Problem 4: Heat Exchangers Analysis (25 points) A counterflow plate-type heat exchanger as shown in the figure below is used to cool propane fuel W 50 mm H 25 mm Saturated Vapor propane Thickness t =5 mm H 25 mm Cooling water Length L The flow rate of the cooling water is 0.2 kg/s, while the flow of the propane is 0.1 kg/s. The water enters the heat exchanger at a temperature of 20°C while the propane enters at its...
A counter-flow heat exchanger is stated to have an overall heat transfer coefficient of 284 W/m2.K when operating at design and clean conditions. Hot fluid enters the tube side at 101°C and exits at 71°C, while cold fluid enters the shell side at 27°C and exits at 42°C. After a period of use, built-up scale in the heat exchanger gives a fouling factor of 0.0004 m2 K/W. The surface area is 93 m². Assume both hot and cold fluids have...
Problem 3 (20 points) A cross-flow heat exchanger consists of a bundle of 32 tubes in a long duct. Hot water at 150°C and a mean velocity of 0.5 m/s enters the tubes having inner and outer diameters of 10.2mm and 12.5mm and has to be cooled to 136°C. The tubes are made of steel of thermal conductivity k-40 W/m.K. Air at 10°c enters the exchanger (unfinned) with a volumetric flow rate of 1.0 m3/s. The convective heat transfer coefficient...
A cross-flow heat exchanger used in a cardiopulmonary bypass procedure cools blood flowing at 4 L/min from a body temperature of 37°C to 25°C in order to induce body hypothermia, which reduces metabolic and oxygen requirements. The coolant is ice water at 0°C, and its flow rate is adjusted to provide an outlet temperature of 13°C. The heat exchanger operates with the blood flow unmixed and the water flow mixed, and the overall heat transfer coefficient is 750 W/m2.K. The...