Chapter 8, Problem 8.9CU

1. An industrial company operates a steam power plant with reheat and regeneration. The steam enters a turbine at 115 bar and 550 °C and expands to the condenser at 0.10 bar. Steam leaves the first stage at 30 bar and then reheat at 470 °C before entering the second stage turbine. At the second stage turbine a mass is extracted to the open feed water heater at 6 bar. Both section of the turbine (first stage and second stage) has adiabatic efficiency of 93 %. A condensate pump exists between the main condenser and the heater. Another pump lies between the heater and condensate outlet line from the heater (condensed extracted steam) a. Compute the enthalpies at each point b. Compute for the mass extracted from the second stage turbine to the open feed water heater c. Efficiency of the cycle.

The figure below provides steady-state operating data for a cogeneration cycle that generates electricity and provides heat for campus buildings. Steam at 1.5 MPa, 280°C, enters a two-stage turbine with a mass flow rate of m1 = 2 kg/s. A fraction of the total flow, y = 0.15, is extracted between the two stages at 0.2 MPa to provide for building heating, and the remainder expands through the second stage to the condenser pressure of 0.1 bar. Condensate returns from the campus buildings at 0.1 MPa, 60°C and passes through a trap into the condenser, where it is reunited with the main feedwater flow. Saturated liquid leaves the condenser at 0.1 bar.

I only need help with part d.   The figure below provides steady-state operating data for a cogeneration cycle that generates electricity and provides heat for campus buildings. Steam at 1.5 MPa, 280°C, enters a two-stage turbine with a mass flow rate of m1 = 2 kg/s. A fraction of the total flow, y = 0.15, is extracted between the two stages at 0.2 MPa to provide for building heating, and the remainder expands through the second stage to the condenser pressure of 0.1 bar. Condensate returns from the campus buildings at 0.1 MPa, 60°C and passes through a trap into the condenser, where it is reunited with the main feedwater flow. Saturated liquid leaves the condenser at 0.1 bar.

Steam is supplied to a two-stage turbine at 40 bar and 350 o It expands in the first turbine until it is just dry saturated, then it is reheated to 350 oC and expanded through the second stage turbine; the isentropic efficiencies of the first and second stage turbines are 84 % and 78 % respectively. The condenser pressure is 0.035 bar. Sketch the process on a T-s diagram and calculate; i. The work output and heat supplied per kg of steam for the plant assuming ideal processes ii. The thermal efficiency of the cycle iii. The specific steam consumption

The property data for a steady state vapor-compression refrigeration cycle with refrigerant 134a as the working fluid are given in the table below. The refrigeration capacity of the cycle is 9.4 tons and the refrigerant mass flow rate is 12.4 kg/min. Determine the net changes in flow exergy rate of the refrigerant passing through the evaporator A (Ed) evap and condenser A(Ed) cond, both in kW. Let po = 1 bar, To = 24°C. (a) A (Ed) evap = Ex: 7.77 kW (b) A (Ed) cond = Ex: 0.999 kW T3, P3 = P2 == Qout 3 2 State p (bar) T (°C) h (kJ/kg) s (kJ/kg. K) www P2 1 1.4 -10.0 243.4 0.9606 2 7.0 64.0 300.8 1.0303 3 7.0 24.0 82.90 0.3113 4 1.4 -18.8 82.90 0.3301 4 == Expansion valve P4 Pl Evaporator ww Condenser Compressor W T₁, Pi m

1.10Water is the working fluid in a reheat-regenerative Rankine cycle with one closed feedwater heater and one open feedwater heater. Steam enters the turbine at 1400 lbf/in.2 and 1000°F and expands to 500 lbf/in.2, where some of the steam is extracted and diverted to the closed feedwater heater. Condensate exiting the closed feedwater heater as saturated liquid at 500 lbf/in.2 undergoes a throttling process to 120 lbf/in.2 as it passes through a trap into the open feedwater heater.The feedwater leaves the closed feedwater heater at 1400 lbf/in.2 and a temperature equal to the saturation temperature at 500 lbf/in.2 The remaining steam is reheated to 900°F before entering the second-stage turbine, where it expands to 120 lbf/in.2 Some of the steam is extracted and diverted to the open feedwater heater operating at 120 lbf/in.2 Saturated liquid exits the open feedwater heater at 120 lbf/in.2The remaining steam expands through the third-stage turbine to the condenser pressure of 3.5…

I need the answer as soon as possible

Describe the Exergy Destruction During Expansion of Steam.

On my online homework, it says the answer for part b, 993.2 kW and part c, 360.06 are incorrect. I also need help with part d.   The figure below provides steady-state operating data for a cogeneration cycle that generates electricity and provides heat for campus buildings. Steam at 1.5 MPa, 280°C, enters a two-stage turbine with a mass flow rate of m1 = 2 kg/s. A fraction of the total flow, y = 0.15, is extracted between the two stages at 0.2 MPa to provide for building heating, and the remainder expands through the second stage to the condenser pressure of 0.1 bar. Condensate returns from the campus buildings at 0.1 MPa, 60°C and passes through a trap into the condenser, where it is reunited with the main feedwater flow. Saturated liquid leaves the condenser at 0.1 bar.