In a power plant steam, steam is continuously extracted from the turbine and in a heat exchanger there is a condensation of the extracted steam. The energy released during condensation of steam is used to operate a heat engine. A heat engine receives thermal energy at a rate of 1250 kJ/min from condensing steam and rejects waste heat to a lake at 20°C at a rate of 800 kJ/min. Determine the lowest possible condensing steam temperature.

In a power plant steam, steam is continuously extracted from the turbine and in a heat exchanger there is a condensation of the extracted steam. The energy released during condensation of steam is used to operate a heat engine. A heat engine receives thermal energy at a rate of 1250 kJ/min from condensing steam and rejects waste heat to a lake at 20°C at a rate of 800 kJ/min. Determine the lowest possible condensing steam temperature.

Refrigeration and Air Conditioning Technology (MindTap Course List)

8th Edition

ISBN:9781305578296

Author:John Tomczyk, Eugene Silberstein, Bill Whitman, Bill Johnson

Publisher:John Tomczyk, Eugene Silberstein, Bill Whitman, Bill Johnson

Chapter44: Geothermal Heat Pumps

Section: Chapter Questions

Problem 1RQ: Geothermal heat pumps, or water-source heat pumps, are classified as either _____loop or _____loop...

See similar textbooks

Similar questions

In a power plant steam, steam is continuously extracted from the turbine and in a heat exchanger there is a condensation of the extracted steam. The energy released during condensation of steam is used to operate a heat engine. A heat engine receives thermal energy at a rate of 1200 kJ/min from condensing steam and rejects waste heat to a lake at 25°C at a rate of 850 kJ/min. Determine the lowest possible condensing steam temperature.
a power plant steam, steam is continuously extractedfromthe turbine and in a heat exchanger there is a condensation of the extracted steam. The energy released during condensation of steam is used to operate a heat engine. A heat engine receives thermal energy at a rate of 1200 kJ/hr from condensing steam and rejects waste heat to a lake at 20°C at a rate of 800 kJ/hr. Determine the lowest possible condensing steam temperature.
Consider a condensing heat exchanger operating with two separate fluids, R-134a and the water. Assuming the operating conditions listed in the table below, and that the pressure drop of the fluids are negligible, find the mass flowrate of the water (kg/s) and Q (kW) transferred between the R-134a and the water. m Enters Exits Fluid Water ? Liquid at T₁ = 5 °℃ Liquid at T₂ = 25 °℃ T2 = 35 °C R-134a 10 kg/min P₁ = 1 MPa and T₁ = 70 °C
b) Hot exhaust gas of a car engine is to be used to heat up water in a heat exchanger. The exhaust gas enters the heat exchanger at 450°C and 0.871 kg/m² density with the rate of 35 m’/min. The water flows into the heat exchanger at 2 MPa and 25°C and leaves as saturated vapour at the same pressure. It is estimated that 10% of the heat given up by the exhaust gas is lost to the surrounding. If the mass flow rate of the exhaust gas is 10 times that of the water, determine i. the mass flow rate of the exhaust gas, (kg/s) ii. the exit temperature of the water, (°C) ii. the rate of heat transfer to the water, (kW) and the exit temperature of the exhaust gas, (°C) iv. Assume exhaust gas as ideal gas with R = 0.287 kJ/kg.K and C, = 1.063 kJ/kg.K Hot Fluid ishaust Gas) Cold Fhid (Wate) Figure Q2: Heat exchanger
Water vapor with a flow rate of 20000 kg / h enters the condenser of a power plant at a pressure of 20 kPa and a dryness degree of 95 percent. In the condenser, there is heat transfer to the river water flowing through the pipes. The temperature rise of the river water is limited to 10 C to prevent thermal pollution. Since the state of the water at the condenser outlet is saturated liquid at 20 kPa pressure, what should be the flow rate of the cooling water.
Water vapor with a flow rate of 20000 kg / h enters the condenser of a power plant at a pressure of 20 kPa and 95% dryness. In the condenser, there is heat transfer to the river water flowing through the pipes. The temperature rise of the river water is limited to 10 ° C to prevent thermal pollution. Since the state of the water at the condenser outlet is a saturated liquid at 20 kPa pressure, what is the flow rate of the cooling water?
4. The refrigerant 134-a enters the compressor of a refrigeration machine as superheated vapor at a flow rate of 0.12 kg/s, a pressure of 0.14 MPa, and a temperature of -10 °C. It exits at a pressure of 0.7 MPa and a temperature of 50 °C. The refrigerant exits the condenser at a temperature of 24 °C and a pressure of 0.65 MPa and is then throttled to a pressure of 0.15 MPa. Show the cycle on a T-s diagram, including the saturated liquid and saturated vapor lines. Also, a) Calculate the heat extracted from the environment per unit time and the power required to operate the compressor, b) The isentropic efficiency of the compressor, c) The coefficient of performance of the refrigeration machine. Note: This is a question from the thermodynamics course. Please provide a clear and prompt solution.
A steam condenser is a heat exchanger which receives exhaust steam from an engine and cooling water from the surroundings. The steam condenses by virtue of the flow of heat from the steam to the cooling water. Thus, there is no shaft work and the changes of kinetic energy are negligible. The incoming 20,000 lb./hr. of exhaust steam have an enthalpy of 1120 Btu/lb. The condensate (water) leaves with h2 = 75 Btu/lb. If 1 lb of cooling water carries away 1 Btu for each degree of temperature rise and it the temperature rise of the cooling water is from 60 to 80°F, how much cooling water must be circulated in lb./hr.?
1) refrigerated space at -35°C by rejecting waste heat to cooling water that enters the condenser at T, C at a rate of 0.25 kg/s and leaves at 26°C. The refrigerant enters the condenser a leaves at the same pressure subcooled by T, C. If the compressor consumes 3.3 kW of power, determine (a) the mass flow rate of the refrigerant, (b) the refrigeration load, Q. (c) the COP. Is this cycle reversible or irreversible? Explain. A commercial refrigerator with refrigerant-134a as the working fluid is used to keep the 1.2 MPa and 50°C and Notes: If the last digit of your student number is less than 5,1 T, is equal to the last digit of your student number. T. 16°C. It is 20°C otherwise. in any ofogse questions, yoe
Air behaving as an ideal gas enters a compressor followed by a constant pressure heat exchanger with the properties and volume flow rate listed in the figure. Do NOT assume constant specific heats. If the compressor has an isentropic efficiency of 83%, determine: a) The mass flow rate through the system (lbm/s) b) The temperature at the compressor exit (Rankines) c) The power input to the compressor per unit mass of air flowing through the system (Btu/lbm) d) The heat transfer rate per unit mass in the heat exchanger (Btu/lbm)
In general, heat exchangers with higher flow rates have greater capacities?
A fruit juice is being heated in an indirect heat exchanger using steam as a heating medium. The product fl ows through the heat exchanger at a rate of 1500 kg/h and the inlet temperature is 20C. Determine the quantity of steam required to heat the product to 100C when only latent heat of vaporization (2200 kJ/kg) is used for heating. The specifi c heat of the product is 4 kJ/(kg C).