Please help with these thermodynamics problems. I promise my friends and I will
ID: 2088695 • Letter: P
Question
Please help with these thermodynamics problems. I promise my friends and I will rate! Description of all the plants and models are listed below. (You need to zoom in a bit in order to see the system diagram clearly by holding ctrl and move your mouse wheel)
Questions, Plots, and Data: Include in Results Section & Key Variables (where applicable): a) What are the powers required by the condensate pump and feedwater pump? What is the heat transfer rate to the water in the boiler? Describe why they are so different b) What is the flow rate of natural gas in standard cubic feet per hour? c) What is the effective boundary temperature of heat transfer to the de-aerate tanks? d) Make a table with the rates of entropy production in each component EXCEPT the regenerator (because it is internally reversible), the water softeners, the water polishers, the whistle valve, and e) What is the daily cost of natural gas for the boiler and of electricity for the pumps? Do these f) What would be the definition of thermal efficiency for this plant? What is that efficiency? Is this g) What is the maximum diameter of the whistle aperture? What is its nozzle efficiency? the whistle. Which three rates are the highest? Why? numbers seem realistic? Why or why not? a good or bad indicator of performance for this plant? h) Plot all state points on a T-s diagram. You may include the diagram in your report and reference it when describing your model if you wish. Make a plot showing the powers required by the pumps Wep and Wrp and the heat transfer rate to the water in the boiler Qboiler as a function of the water supply flow rate ms from 30,000 lbm/hr to 50,000 lbm/hr. Explain the trends. i) j) Make a plot showing the fraction of supply steam flow required for the whistle, (mw/ms), as a function of the whistle aperture diameter, Dw, from 0.1 to 3 in. Explain the trend.Explanation / Answer
the specific work is calculated in the pump w=vf*(P5-P4)/nb vf=0.001014 from saturate water table
w=1.708e3 J/kg mp mass flow mp=4.662kg/s Wb=power of pump Wb = 7.963kW
calculation of the heat in the boiler
Qcal=mp*hfg(130psi) Qcal=4.662kg/s*2031.12KJ/kg Qcal=9.469MW
With the heat in the boiler and the calorific value of the gas the gas consumption is calculated
gas density = 0.648m3/kg LHV=50.02MJ/kg Q=LHV*mgas/0.75 mgas=0.252kg/s Vgas=mgas/dgas
Vgas=1402m3N/hr