please solve complete in one hour
Posted: Tue Apr 12, 2022 9:56 am
please solve complete in one hour
The combined heat and power plant (CHP, states 6 to 8) shown below is operated with fuel B at ambient conditions pu = 1 bar and tu = 5 The usable waste heat from the CHP unit (Q1 + Q . AG) is transferred to a steam turbine process with organic working medium (ORC: Organic Rankine Cycle, states 1 to 5). The engine output of the CHP unit Prhkw = 1.44 MW and the turbine output Pt of the ORC process are passed on to a generator. PBHKW حاضغي met 10 4 Motor and3 Heat exchanger Heat exchanger -RP - Pump Turbine Heat exchanger 1 ma RC 5 Q 2 AB Changes in condition 12: Irreversible adiabatic pressure increase of the working medium with mass flow NRc from state 1 (p = 0.48 bar) to state 2 (p2 = 3.60 bar). 2: Isobaric Heating of the working medium with the Waste heat flow Q1 = 0.92 MW of the CHP motor up to state 3 (straight boiling fluid). The heat exchanger is adiabatic to the outside. 3 →4: Isobaric evaporation of the working medium with the waste heat flow Quc. of the CHP exhaust gas to state 4 (just fully evaporated). The heat exchanger is adiabatic to the outside and a temperature difference of AT4,8 = 100 K is set between states 4 and 8. 4 5:Irreversibleadiabatic expansion of the working medium in the turbine with the isentropic efficiency n st = 0.85 to state 5 (ps = p.). 5 1:Isobariccondensation of the working medium up to state 1 (even completely liquefied). 6 7: Combustion of fuel B (n = 0.12 kg/s) in the CHP engine with the calorific value AV hu = 25.2 MJ/kg (waste heat flow Qi is used by the ORC process). 7-8: Isobaric cooling of the CHP exhaust gas (ING = 7 kg/s) from state 7 (ta = 420 C) to state 8 (waste heat flow QG is transferred from the ORC-. process). The exhaust gas is to be regarded as an ideal gas and des- The heat capacity is constant in the temperature range under consideration with C9, g = 0.8104 kJ/(kg K).
Notes: Please give results for entropy and mass flows to four decimal places (e.g. 6.3567), and all other results to two decimal places (e.g. 0.01 or 9.87 or 242.00)! a) Determine the evaporation and condensation temperature (in K) of the working medium in the ORC process. b) Determine the temperature (in K) of the CHP exhaust gas released to the environment (condition 8). c) is state point 5 in the homogeneous region or two-phase region ? Explain this on the basis of the entropy. d) Justify which of the three given T, s diagrams corresponds to the above. The ORC process described in the report is qualitatively correct. e) Determine the enthalpy (in kJ/kg) of states 1, 3, 4 and 5. Use only the following enthalpy values for the following parts of the task: 1 3 4 5 State points h/kJ/kg 126 240 429 388 f) Determine the mass flow rate of the ORC process NRC (in kg/s). Use only the mass flow rate irc = 8.75 kg/s for Hollowing parts of the task. g) Determine the enthalpy (in kJ/kg) of state 2. Use only the enthalpy h2 = 140 kJ/kg for the following parts of the task. h) Determine the pump and turbine power (in kW) Only use the following services and flows for the following parts of the task: IP IP QM Q IPBHK WI 1440 AGI 1654 kW 135 395 920 i) Determine the percentage exergetic efficiency of the total pores (CHP+ORC). Notes: The pump is driven by the turbine. The exergetic expenditure is given by the calorific value. 7
| a) crit Point crit Point crit, Point در شرشر 3 4 3 3 4 2 2 5 5 TL S SL /TL SL /TL Substance data organic working medium Two-phase ای !!ي pth! kJ/kg h!! kJ/kg bar kJ/(kg K) kJ/(kg K) 0.48 12.77 113.76 323.34 0.4604 1.1718 3.60 54.99 217.50 389.22 0.7734 1.2444 Single-phase S . bar pth kJ/kg 85.20 kJ/(kg K) 0.3599 0.48 0.00 0.48 12.00 112.14 0.4542 0.48 24.00 342.60 1.2354 0.48 36.00 364.14 1.3020 0.48 48.00 386.70 1.3680 0.48 60.00 410.34 1.4328 0.48 72.00 435.00 1.4976 3.60 0.00 85.50 0.3592 3.60 12.00 112.44 0.4534 III 3.60 24.00 140.22 0.5449 3.60 36.00 169.08 0.6342 3.60 48.00 199.26 0.7224 3.60 60.00 399.96 1.2738 3.60 72.00 426.12 1.3422
- Please Solve Complete In One Hour 1 (120.11 KiB) Viewed 21 times
Notes: Please give results for entropy and mass flows to four decimal places (e.g. 6.3567), and all other results to two decimal places (e.g. 0.01 or 9.87 or 242.00)! a) Determine the evaporation and condensation temperature (in K) of the working medium in the ORC process. b) Determine the temperature (in K) of the CHP exhaust gas released to the environment (condition 8). c) is state point 5 in the homogeneous region or two-phase region ? Explain this on the basis of the entropy. d) Justify which of the three given T, s diagrams corresponds to the above. The ORC process described in the report is qualitatively correct. e) Determine the enthalpy (in kJ/kg) of states 1, 3, 4 and 5. Use only the following enthalpy values for the following parts of the task: 1 3 4 5 State points h/kJ/kg 126 240 429 388 f) Determine the mass flow rate of the ORC process NRC (in kg/s). Use only the mass flow rate irc = 8.75 kg/s for Hollowing parts of the task. g) Determine the enthalpy (in kJ/kg) of state 2. Use only the enthalpy h2 = 140 kJ/kg for the following parts of the task. h) Determine the pump and turbine power (in kW) Only use the following services and flows for the following parts of the task: IP IP QM Q IPBHK WI 1440 AGI 1654 kW 135 395 920 i) Determine the percentage exergetic efficiency of the total pores (CHP+ORC). Notes: The pump is driven by the turbine. The exergetic expenditure is given by the calorific value. 7
| a) crit Point crit Point crit, Point در شرشر 3 4 3 3 4 2 2 5 5 TL S SL /TL SL /TL Substance data organic working medium Two-phase ای !!ي pth! kJ/kg h!! kJ/kg bar kJ/(kg K) kJ/(kg K) 0.48 12.77 113.76 323.34 0.4604 1.1718 3.60 54.99 217.50 389.22 0.7734 1.2444 Single-phase S . bar pth kJ/kg 85.20 kJ/(kg K) 0.3599 0.48 0.00 0.48 12.00 112.14 0.4542 0.48 24.00 342.60 1.2354 0.48 36.00 364.14 1.3020 0.48 48.00 386.70 1.3680 0.48 60.00 410.34 1.4328 0.48 72.00 435.00 1.4976 3.60 0.00 85.50 0.3592 3.60 12.00 112.44 0.4534 III 3.60 24.00 140.22 0.5449 3.60 36.00 169.08 0.6342 3.60 48.00 199.26 0.7224 3.60 60.00 399.96 1.2738 3.60 72.00 426.12 1.3422