Chapter 7, Problem 7.13E

An open feedwater heater is a direct-contact heat exchanger used in vapor power plants. Shown in the figure below are operating data for an open heater with H,0 as the working fluid operating at steady state. Ignoring stray heat transfer from the outside of the heat exchanger to its surroundings and kinetic and potential energy effects, determine the rate of entropy production, in kW/K. (Hint: Use the first law to find the mass flow rates) Also determine state point 1 and 2 on a T-s diagram, then mix them and show the outcome is 3. Show 3 on the T-s diagram. P2 = 3 bar x2 = 0.92 (2) P3 = 3 bar saturated liquid m3 = 80 kg/s P1 = 3 bar T1 = 36°C Open Feedwater (3) Heater

6.110 Figure P6.110 shows a simple vapor power plant operating at steady state with water as the working fluid. Data at key locations are given on the figure. The mass flow rate of the water circulating through the components is 109 kg/s. Stray heat transfer and kinetic and potential energy effects can be ignored. Determine a. the net power developed, in MW. b. the thermal efficiency. c. the isentropic turbine efficiency. t2 d. the isentropic pump efficiency. e. the mass flow rate of the cooling water, in kg/s. f. the rates of entropy production, each in kW/K, for the turbine, condenser, and pump. P = 100 bar T = 520°C %3D Power out Turbine P2 = 0.08 bar 2 = 90% %3D Steam Cooling water in at 20°C generator Condenser Pa= 100 bar T= 43°C Cooling water out at 35°C 4. Pump 3 P3 0.08 bar Saturated liquid Power in FIGURE P6.110 2. www

Figure shows data for a portion of the ducting in ventilation system operating at steady state. The ducts are well insulated and the pressure is very nearly 1 bar throughout. Assuming the ideal gas model for air with Cp  = 1 kJ/kg · K. and ignoring kinetic and potential energy effects, determine: (a) the temperature of the air at the exit, in °C. (b) the exit diameter, in m. (c) the rate of entropy production within the duct, in kJ/min.

Using image below Evaluate the exergy X1 of the initial state 1 and answer the following question: • Is the useful work in the process 1 → 2 → DS smaller, equal, or greater than exergy X1? • Discuss your result

Answer please

Figure shows a simple vapor power plant operating at steady state with water as the working fluid. Data at key locations are given on the figure. The mass flow rate of the water circulating through the components is 109 kg/s. Stray heat transfer and kinetic and potential energy effects can be ignored. Determine: (a) the mass flow rate of the cooling water, in kg/s. (b) the thermal efficiency. (c) the rates of entropy production, each in kW/K, for the turbine, condenser, and pump. (d) Using the results of part (c), place the components in rank order, beginning with the component contributing most to inefficient operation of the overall system. verl

An open feedwater heater is a direct-contact heat exchanger used in vapor power plants. Shown in the figure below are operating data for an open feedwater heater with H2O as the working fluid operating at steady state, where T1 = 41 °C.   Ignoring stray heat transfer from the outside of the heat exchanger to its surroundings and kinetic and potential energy effects, determine the rate of entropy production, in kW/K.

A balloon filled with helium at 20°C, 1 bar and a volume of 0.5 m³ is moving with a velocity of 15 m/s at an elevation of 0.5 km relative to an exergy reference environment for which To = 20°C, po = 1 bar. Using the ideal gas model with k = 1.67, determine the specific exergy of the helium, in kJ.

Step by step solution please I only have 1 attempt thank you