A steam power plant operates on a theoretical reheat cycle. Steam at 25 bar pressure and 400°C is supplied to the high pressure turbine. After its expansion to dry state, the steam is reheated at constant pressure to its original temperature. Subsequent expansion occurs in the low pressure turbine to a condenser pressure of 0.04 bar. Considering feed pump work, Calculate: (i) Quality of steam at entry to condenser (ii) Thermal efficiency (iii) Specific steam consumption.

A steam power plant operates on a theoretical reheat cycle. Steam at 25 bar pressure and 400°C is supplied to the high pressure turbine. After its expansion to dry state, the steam is reheated at constant pressure to its original temperature. Subsequent expansion occurs in the low pressure turbine to a condenser pressure of 0.04 bar. Considering feed pump work, Calculate: (i) Quality of steam at entry to condenser (ii) Thermal efficiency (iii) Specific steam consumption.

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

Chapter28: Special Refrigeration Applications

Section: Chapter Questions

Problem 15RQ: Why is two-stage compression popular for extra-low-temperature refrigeration systems?

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Why is two-stage compression popular for extra-low-temperature refrigeration systems?
Problem 1: The boiler of a power steam cycle operates at 6000 kPa and the condenser at 50 kPa. At the entrance to the turbine, the temperature is 500°C. The isentropic efficiency of the turbine is 90 percent, pressure and pump losses are negligible, and the water leaving the condenser is subcooled by 6.3°C. The boiler is sized for a mass flow rate of 18 kg/s. You are asked to: a. Represent the cycle on P-v and T-s diagrams. b. Compute the rate at which heat is added in the boiler. c. Compute the power required to operate the pumps. d. Determine the net power produced by the cycle. e. Compute the thermal efficiency.
A steam power plant operates on a theoretical reheat cycle. Steam at 25 bar pressure and 400°C is supplied to the high pressure turbine. After its expansion to dry state, the steam is reheated at constant pressure to its original temperature. Subsequent expansion occurs in the low pressure turbine to a condenser pressure of 0.04 bar. Considering feed pump work, Calculate: (i) Quality of steam at entry to condenser (ii) Thermal efficiency (iii) Specific steam consumption.
A medium size power station is used to produce 30 MW net power for a refinery. The station uses steam as the operating fluid and operates according to the Carnot cycle between the pressure limits of 0.4 bar and 35 bar. Steam enters the boiler as a saturated liquid and leaves it as a dry saturated vapour.(iii) Determine the dryness fraction of the steam that is fed to the condenser.
Problem 1 In a Rankine Thermodynamic cycle, steam leaves the boiler and enters the turbine at 600 psia, 800 °F. The condenser pressure is 1 psia. After presenting a schematic of the problem in addition to clearly labeled and explained T-s and h-s diagrams, you are asked to determine the following: (a) Pump work required per Ibm of working fluid. Quality of fluid at turbine inlet. Work output of turbine per lbm of working fluid. Energy input to the boiler per lbm of working fluid. Heat rejection by the condenser per Ibm of working fluid. Determine the cycle thermal efficiency. (d) (e) (f)
In a reheat cycle, steam at 165 bar and 600°C is supplied to the turbine. The steam at 18.5 bar during the expansion is withdrawn and reheated to 490 degrees * C Then the expansion is further carried out to condenser pressure of 0.03 bar. (i) Determine the thermal efficiency and (ii) Steam flow rate if the output from the turbine is 60 MW. Assume all ideal processes.
Q.3 A. Calculate the thermal efficiency of a Rankine cycle in which the steam is initially dry saturated at 2 Mpa and the condenser pressure 75 kN / m². Express this efficiency as a percentage of a Carnot cycle efficiency of the same limits of temperature. B. If the steam leaves the boiler at 350 ° C with the same pressure of the boiler and condenser given above. Explain why the Rankine efficiency in (A) is less than in (B), and why the ratio of efficiencies of the respective Rankine and Carnot is greater.
2. Steam at 13.8 MPa and 940°C enters a turbine and expands to 3.8 MPa where m1 is extracted for feedwater heating, the remainder is withdrawn and reheated to 720°C. Expansion then occurs to 0.90 MPa, where m2 is extracted for feedwater heating. The remaining steam is withdrawn and reheated to 5800C. Final expansion now OCcurs to a condenser pressure 0.028 MPa. For an ideal cycle and 1kg of steam, find a) Wnet b) efficiency
Complete and legible solution please; The condensing pressure for a Rankine engine is 1 bar. Calculate the work net in KW and thermal efficiency of the cycle when the steam at the beginning of expansion is at 50 bar and (a) saturated, (b) 350 OC, and (c) 640 OC. Note: 1 bar is equal to 100 Kpa
A power station consists of a four-unit coal fired power station, having a combined capacity of 2,880 MW. The current efficiency of each unit is around 37.7%. You are asked to improve the thermal efficiency of each unit by lowering the condenser pressure. To simplify this task, assume that each unit operates on a simple ideal Rankine cycle. If the superheated vapour enters the turbine at 10 MPa and 500 ֯C and is cooled in the condenser at a lower pressure 10 kPa, determine the quality of the steam at the turbine exit and the thermal efficiency of the cycle for one unit.
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1. In a Rankine cycle, steam enters the turbine at 2.5 MPa and condenser of 50 kPa.What is the thermal efficiency of the cycle? 2. Steam enters the superheater of a boiler at a pressure of 25 bar and dryness of 0.98 and leaves at the same pressure at a temperature of 370OC. Calculate the heat energy supplied per kg of steam supplied in the superheater. Kindly answer question 1 and 2 and show solution. Please help me. Thank you