Consider the flow of engine oil
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HEAT+MASS TRANSFER:FUND.+APPL.
- An isosceles triangle channel having an apex angle of 60 ° and length of 20 m is being heated uniformly with electric heaters. Water flows through this channel with an inlet temperature of 15 °C and mass flow rate of 1 kg/s and is 10 m being heated to 45 °C at the exit of the tube. Assuming the water flow is fully developed through the channel what is the average convection heat transfer coefficient? Also determine the pumping power. 10 m 16 marrow_forwardRefrigerant R-134a enters to the compressor of a refrigeration machine at a pressure of 140 kPa and a temperature of -10 °C, then comes out at a pressure of 1 MPa . Volumetric flow of the refrigerant entering the compressor 0.23 m3 /minute. Refrigerant enters throttling valve at 0.95 MPa pressure and 30 °C, and comes out the evaporator at -18 °C as saturated steam. Adiabatic efficiency of the compressor It is 78%. Show the cycle in the T-s diagram. Then calculate: a) Power required to run the compressor b) The heat withdrawn from the cooled environment in unit time, COPsm=? c)Between the evaporator and the compressor, pressure drop of the refrigerant and its heat gain.arrow_forward4. An experimental test rig is used to examine two-phase flow regimes in horizontal pipelines. A particular experiment involved uses air and water at a temperature of 25°C, which flow through a horizontal glass tube with an internal diameter of 25.4 mm and a length of 40 m. Water is admitted at a controlled rate of 0.026 kgs¹ at one end and air at a rate of 5 x 104 kgs-¹ in the same direction. The density of water is 1000 kgm 3, and the density of air is 1.2 kgm 3. Determine the mass flow rate, the mean density, gas void fraction, and the superficial velocities of the air and water. Answer: 0.02605 kgs-¹, 61.1 kgm-³, 0.94, 0.822 ms-¹, 0.051 ms-¹arrow_forward
- The oil (cp= 1759 J/kg.℃) from an oil cooled electric transformer is cooled from 79.5℃ to 29.4℃ at the rate of 1360.5kg per hour. This is done in an oil-water heat exchanger that receives 2948kg/hr of water at 15.6℃. For the heat exchanger U=295 W/m2℃. Find the exit temperature of water. answer: 25.294 degrees Carrow_forwardAir (Cp = 1005 J/kg °C) enters a cross-flow heat exchanger at 10 C at a rate of 3 kg/s, where it is heated by a hot water stream (Cp = 4190 J/kg °C) that enters the heat exchanger at 95 °C at a rate of 1 kg/s. Determine the maximum heat transfer rate and the outlet temperatures of the cold and the hot water streams for that case.arrow_forwardFluid X56-1 (density = 1300 kg/m3; M = 253 kg/kmol) is pumped at a rate of 4.58 m3/hour from a storage tank to a processing unit. The pressure at the inlet to the processing unit is atmospheric while the air pressure in the storage tank is 1.25 atm. The storage tank contains fluid with a height of 1.8 m. The pump, located just outside the bottom of the tank, has a pressure at the exit point of 350 kPa. The pump is located 15 m lower than the processing unit. The pipe transporting the fluid is commercial steel with an inside diameter of 3 cm. Assume the viscosity is 42 mPa*s.a) What is the Reynold’s number for flow in the pipe?b) Is the flow laminar or turbulent?c) What is the pressure (kPa) at the inlet of the pump?d) What is the power (kW) supplied by the pump?e) Calculate the length (m) of the pipe.arrow_forward
- A heat exchanger was installed purposely to cool 0.50 kg of gas per second. Molecular weight is 28 and k=1.32. The gas is cooled from 150⁰C to 80⁰C. Water is available at the rate of 0.30 kg/s and at a temperature of 12⁰C. Calculate the exit temperature of the water.arrow_forwarda saturated steam is to be condensed at temperature of 50 °C to produce a saturated water. The cooling water is drawn from a nearby river and enters the tubes of the condenser at 18 °C and leaves it at 37 °C. The tubes of the condenser are thin of a diameter 15 mm and 5 m long and their number is 773 tubes. Determine the efficiency of the condenser, cooling water flow rate (kg/s), and steam flow rate (kg/s) considering the following date: , (water side) = 5000W I m².K ;h. = (steam side) = 60000 W / m².K ;R, =R,, =0.0001 m:CIW Answer (59.37%,115.576kg/s,3.87 kg/s). %3Darrow_forwardThe double pipe 1 m length heat exchanger is essentially a set of concentric pipes. One fluid flows within the smaller pipe and the other in the annulus. For such an exchanger (outer diameter of the inside pipe is 2 cm; inner diameter of the outside pipe is 4 cm), water flows in the annular space at an average velocity of 0.2 m/s. The water, which cools an organic flowing in the central pipe, has a temperature change from 16 to 28 . In this case calculate the heat transfer coefficient for the water assuming that the exchanger is heavily insulated and that the wall temperature on the inside of the annulus (outside of central pipe) is 30 . And heat transfer rate=?, heat transfer flux=?arrow_forward
- A heat exchanger is being used to transfer heat between water and a benzene. The benzene enters the heat exchanger at 1.2 m3/h with a temperature of 90 C. The water enters the heat exchanger at 1 m3/h at a temperature of 15°C. The UA product of the heat exchanger is found to be 2800 kJ/h-°K. . Determine (a) the outlet temperature of water and benzene (b) the heat transfer rate between the fluids for a counter-flow heat exchanger.arrow_forwardThe pressure in a pipeline that transports helium gas at a rate of 2 kg/s is maintained at 1 atm by venting helium to the atmosphere through a 5-mm- internal-diameter tube that extends 15 m into the air as shown in figure beside. Assuming both the helium and the atmospheric air to be 25 oC, determine: • A- the mass flowrate of helium lost to the atmosphere through the tube. • B- the mass flowrate that infiltrates into the pipeline • C- the flow velocity at the bottom of the tube where it is attached to the pipeline that will be measured by an anemometer in steady operationarrow_forwardAir at (2.9000x10^2) K is entering in a circular pipe at 101325 Pa as shown in Figure. The velocity of the air at the pipe entrance is (1.00x10^0) m/s. The diameter of the pipe is 0.1m. Specific gas constant of air is 287 J/kg-K. Specific heat of air is 1000 J/kg-K. Find the outlet temperature if 2000 J of heat is added to the pipe.arrow_forward
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