Problem 05.089 - Heat exchanger Hot exhaust gases of an internal combustion engine are to be used to produce saturated water vapor at 2 MPa pressure. The exhaust gases enter the heat exchanger at 400°C at a rate of 32 kg/min while water enters at 15°C. The heat exchanger is not well insulated, and it is estimated that 10 percent of heat given up by the exhaust gases is lost to the surroundings. If the mass flow rate of the exhaust gases is 15 times that of the water, determine the temperature of the exhaust gases at the heat exchanger exit and the rate of heat transfer to the water. Use the constant specific heat properties of air for the exhaust gases. The constant pressure specific heat of the exhaust gases is taken to be cp 1.045 kJ/kg "C. The inlet and exit enthalpies of water are 62.98 kJ/kg and 2798.3 kJ/kg. = Exhaust gases 400°C T 2 MPa sat. vap. Heat exchanger Water 15°C The temperature of the exhaust gases is The rate of heat transfer is kW. °C.

Wet-mixture exhaust from a turbine at 7 kPaa at a rate of 75 kg/s enters a condenser with a total surface area of 2950 m2. The mixture has a moisture content of 10% and leaves the condenser as saturated liquid. The cooling water volumetric flow rate is 4.413 m3 /s and enters at 20 oC. Find the LMTD and overall heat transfer coefficient. NOTE: AT 7 kPaa, tsat = 39 oC, hf = 163.4 kJ/kg, hfg = 2572.5 kJ/kg (four decimal places for final answer)

Ammonia and air pass through the heat exchanger. While the ammonia is entering as a superheated vapor at 16 bar pressure and 60C temperature it is leaving as a saturated liquid at the same pressure but unknown temperature. The ammonia mass flow rate is 400 kg/hour. Air is flowing backward and is heated from 17C to 42C at the constant pressure of 2 bars. NOTE: Find air properties from https://www.peacesoftware.de/einigewerte/luft_e.html a.Draw the sketch of the heat exchanger showing all thermodynamic parameters (P, T, etc.)   Please show all steps of solution

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/m²K. Calculate the heat exchanger surface area required if the air is unmixed and the exhaust gases are mixed .CPair = 1030 J/kg k Power plant Exhaust in, 450°C Exhaust gases Heat exchanger Air in, 70°C Air out, 250 ℃ Air intakes E Out

Water is used in a heat exchanger to cool 5 kg/s of air from 400 to 200 C. Calculate the minimum mass flow rate of the water if Twater =10 C.

Question attached

A boiler has a mass flow rate of 3 tons/hour of feed water at a temperature of 28 C and a pressure of 1 atm. This water is pumped to a pressure of 30 atm assuming a constant temperature. Pump efficiency is 90%. The water leaving this pump is heated in an Economizer heat exchanger to its saturation point temperature in the saturated water phase? What is the rate of heat supplied by the Economizer to heat the pump exit feedwater to the above conditions

A stream of CO2 at pressure 1 bar, flowing at 10 mol/s, from 150°C to 300°C is to be heated ina counter current heat exchanger. To do this task a stream of high-pressure steam available at 40bar and 400°C is used, as shown in the following figure. The entire system is well insulated, asshown. It is undesirable for the steam to condense in the heat exchanger tubes. Assume thepressure of each stream stays constant as it flows through the heat exchangeWhat is the minimum volumetric flow rate, in m3 /s, required of the inlet steam to keep it from condensing at the exit?

. The exhaust gas regenerator (counter-flow heat exchanger) for a gas turbinehandles 1.9 kg/sec of air from its compressor and heats it by means of 2.2 kg/secof hot exhaust gas. Exhaust gas enters the regenerator at 596°C and leaves at312°C. Compressed air enters the regenerator at 220°C. For this temperaturerange a constant pressure specific heat for the exhaust has may be estimated at1090 J/kg-°C. Assume no heat transfer other than between the generator fluids.Determine the log mean temperature difference for the exchanger, °CA. 16.98 B. 26.98 C. 36.98 D. 46.98

Problem 4. Consider a steam turbine in which steam enters at 10.45 MPa and 780 K with a flow rate of 38.739 kg/s. A portion of the steam is extracted from the turbine after partial expansion at three different locations as shown in the sketch. The extracted steam is then led to various heat exchangers. The mass flow rates and the temperatures and pressures at each extraction point are given in the following table: Extraction Location m (kg/s) P (MPa) T (K) 4.343 3.054 620 Steam turbine Inlet 4.345 0.332 482 3 2.871 0.136 x = 0.949 The remaining wet steam exits the turbine at 11.5 kPa with a quality of 0.88. Estimate the power produced by the turbine assuming adiabatic operation and neg- ligible kinetic and potential energies for all streams. Exit 12 3 Extraction locatione 123