Combined Heat & Power Plant

1. Combined Heat & Power Plant Group Meeting # 2 Mentor: Shannon Brown, PE Michael Bentel Jeremy David Erik Peterson Arpit Shah

2. Questions from Group Meeting #1 • What are the specifications for fuel? • ~80 – 85% - C2+ • ~ 10% - CH4 • ~ 5 % - N2 • ~ 2 % - CO2 • What is the primary heat source for the boiler? • Combustion gases from Gas Turbine along with Natural Gas • Boiler – Heat Recovery Steam Generator (H.R.S.G.) • What is the cheapest source of fuel for this plant? • Waste hydrocarbons from **Team Alpha**

3. Questions (Cont’d) • What is the minimum water purity required for boiler feed water (BFW)? • Dissolved O2: < 0.007 ppm • Total Fe: < 0.01 ppm • Total Cu: <0.01 ppm • Total Hardness: 0.05 • pH: 8.8-9.6 • Silica: <2.00 ppm • Conduction < 150 • Total Dissolved Solids (TDS): 0.1 • How is the effluent stream from the boiler being addressed? • The Effluent stream will be sent through the flue gas purification system

4. Group Meeting 2 Objectives • Flow Sheets • Material & Energy Balances • Process Flow Sheet Frozen • Data • Hand Calculations • Rough Economics

5. Outline • Design Basis √ • Block Flow Diagram √ • Process Flow Diagram  IN PROGRESS • Material and Energy Balance  IN PROGRESS • Calculations  IN PROGRESS • Annotated Equipment List (Data Sheet)  IN PROGRESS • Economic Evaluation factored from Equipment Costs • Utilities • Conceptual Control Scheme • General Arrangement – Major Equipment Layout • Distribution and End-use Issues Review • Constraints Review • Applicable Standards  IN PROGRESS • Project Communications File  IN PROGRESS • Information Sources and References  IN PROGRESS

6. Pumps and Compressors • As stated before, compressor is going to be used to provide plant air • Because instrument air must be very dry to avoid plugging and corrosion, a rotary screw oil free air compressor is commonly put through a dryer

7. Air Compressor Material Balance H2O (cfm) Oil - Free AirCompressor P1 , T1 Wet (cfm) P2, T2, Wet (cfm) Refrigerated Air Dryer Dry (cfm)

8. Compressed Air – Energy Balances • Dryer Mass Balance • ft3* 1 lb DA/ ft3* lb H2O/ lb DA = lbH2O * ft3/lb= cfm H2O • Work Done in Compressed Air • -W=P1ν1(n/(n-1))[(P2/P1) (n-1)/n-1] =ZRT(n/(n-1))[(P2/P1) (n-1)/n-1] • Heat of Compression: T2=T1(P2/P1)(n-1/n) 8

9. One of the most expensive sources of energy of plant 10% of electricity consumption goes to compressed air generation Several compressors may be installed for maintenance purposes as a stand-by spare Compressor Costs Annual Electricity Cost =

10. Williston, ND - Data • Dry Bulb Temperature : 92°F • Wet Bulb Temperature: 66°F • Highest Relative Humidity: 90%

11. Induced – Draft Cooling Tower PFD

12. Cooling Tower – General Material Balance Dry Air Mass Balance ṁa1 = ṁa2 = ṁa WaterMass Balance ṁhw + ṁa1∙ω1 = ṁcw + ṁa2∙ω2 = ṁhw-ṁcw = ṁa(ω2-ω1) Also, ṁMU = ṁa(ω2- ω1) + ṁBD

13. Cooling Tower – Energy Balance Ėin– Ėout = ΔĖsys ΔĖsys = 0 0 = (ṁa2∙ha2) + (ṁcw∙hcw) – (ṁa1∙ha1) – (ṁhw∙hhw) ṁa = **Assuming Steady State and Adiabatic System**

14. Data Used to Calculate M&E Balance

15. Results from M&E Balance - ECT **Calculated at 11.8 psi

16. Turbine & Boiler System

18. Results from Boiler Material Balance *Based on ideal system (100% efficiency/recovery, no lose of water/steam due to system leakage)

19. Results from Boiler Energy Balance Superheated *Calculated using steam tables and superheated steam tables for latent heat and superheated work, respectively; averaged heat capacity over temperature ranges for sensible heat; PV work for compression.

20. Flue Gas Clean Up • Particle Removal • Gaseous Contaminates Removal • Wet Scrubber – Utilizes water for removal • Wet-Dry Scrubber – Utilizes aqueous spray for removal • Dry Scrubber – Utilizes dry powder for removal • Nitrogen Oxide Removal – Utilizes catalysis for removal • Stack – Measures contaminates in out flowing combustion gases

21. USEPA & NDEPA Flue Gas Requirements • NOx: 100 ppb, averaged over one hour • SOx: 1 - hour standard at a level of 75 parts per billion  • CO: 8 - hour primary standard at 9 parts per million (ppm) 

22. Turbine Material Balance • Gas Turbine Airin+ Fuelin= Exhaust Gasout mAir + mfuel = mExhaust • Steam Turbine High Pressure Steamin= Process Steamout + Condensing Steamout mHigh-P = mProcess + mcondensed

23. Turbine Energy Balance • Gas Turbine Combustion Gasin = Workout + Exhaust Gasout (m*H)Combustion = (effturbine*(m*H)Combustion+ ((m*H)Combustion - effturbine*(m*H)Combustion)) • Steam Turbine High Pressure Steamin = Process Steamout+ Condensing Steamout + Workout (m*H)high P. = Σ(m*H)process + (m*H)condensed + effturbine*(Σ((m*H)high P – (m*H)process) + ((m*H)high P. – (m*H)condensed))

24. Relating Turbine and BoilerEnergy & Material Balance • Energy - Combustion Gasin – Workout = Exhaust Gasout = Exhaust Gasin= Steamout + Exhaust Gasout – Feed Waterin • Material – Airin + Fuelin = Exhaust Gasout = Exhaust Gasin = Steamout + Exhaust Gasout – Feed Waterin

25. Results from M&E Balance – Gas Turbine

26. Equipment List

27. CHP - Rough Economics Where, • Ce= Purchased Equipment Cost • a & b = Cost Constants • S = Size Parameter • n = Exponent for that type of equipment **All equipment costs are based on U.S. Gulf Coast Basis, Jan 2010 (CEPCI index = 532.9)**

28. Equipment Cost Table **Calculated Using Cost Estimation Equation in “Chemical Engineering Design”, Towler **Calculated Using “Plant Design and Economics for Chemical Engineers” Online Simulator, 5th Edition **Estimated Cost from GE

29. Equipment Cost

30. Economics – Cont’d • Total Equipment Cost: $27,032,416 • Total Cost of Installation: $117,861,333 *Assumption: 4.36*(Cost of Equipment) • Total Cost of Engineering: $8,109,724 *Assumption: Engineering costs = 0.30(Cost of Equipment) Total Cost = Cost of Equipment + Installation + Engineering = $153,003,474

31. QUESTIONS???