ChemEngDP

MATLAB / Python (U/C) code for mechanical design, sizing & capex/opex calculations

The intention is to use these quickly as "black-box" functions for the purposes for TAC optimization in the second half of the detail design of the main equipment (e.g. PFR length, selection of pumps/compressors etc.)

• QUICK START:

  • Download the required .m files under \lib directly to your project path; or

  • Download the entire \lib to path, then right click \lib > Add to Path > Selected Folders in MATLAB

To use, download the required .m files into the same folder as your existing code, and call the following functions depending on your situation:

Quick tip: Always use help to check the required units to avoid unit conversion errors!

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Mechanical Design & Ancillary Equipment Sizing - dsg

help dsg - retrieves help documentation on functions, inputs and arguments

Functions:

• dsg.designhorzpres - perform entire mechanical design for horizontal pressure vessels

• dsg.designvertpres - perform entire mechanical design for vertical pressure vessels

• dsg.designvac - perform entire mechanical design for vacuum vessels

• dsg.sizecompressor - conducts compressor sizing

• dsg.sizepump - conducts pump sizing

• dsg.sizeHE_heater - conducts heat exchanger sizing for heating stream

• dsg.sizeHE_cooler - conducts heat exchanger sizing for cooling stream

To call intermediate functions (e.g. calculate shell thickness, calculate max. allowable stress, calculate wind allowance etc.), refer to documentation (call help dsg).

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CAPEX Calculation - capex

help capex - retrieves help documentation on functions, inputs and arguments

Constants:

• capex.CEPCIyy - retrieves annual CEPCI index for 20yy (where yy = 01, 18 or 19)

• capex.USSGyy - retrieves USD:SGD forex rate for 20yy year-average

• capex.CPIzzyy - retrieves country zz's consumer price index (CPI) for 20yy year-average (where zz = 'SG' or 'US')

  • Reference year for CAPCOST = 2001 (as of Turton et al. 5th Ed.)

  • Reference year for utilities cost = 2018 (as of Turton et al. 5th Ed.)

Functions:

• capex.eqptpurcost - calculates purchased equipment cost

• capex.pressurefacves - calculates pressure factor for vessels

• capex.pressurefacanc - calculates pressure factor for anciliary equipment

• capex.baremodfac - calculates bare module factor

• capex.baremodcost - calculates bare module cost

• capex.totmodcost - calculates total module cost

• capex.grasscost - calculates grassroots cost

To do: Import relevant data on constants for MOC and pressure factors as needed, only if there are significant benefits of doing so.

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OPEX Calculation - opex

help opex - retrieves help documentation on functions, inputs and arguments

Constants:

• opex.CEPCIyy - retrieves annual CEPCI index for 20yy (where yy = 01, 18 or 19)

• opex.USSGyy - retrieves USD:SGD forex rate for 20yy year-average

• opex.CPIzzyy - retrieves country zz's consumer price index (CPI) for 20yy year-average (where zz = 'SG' or 'US')

  • Reference year for CAPCOST = 2001 (as of Turton et al. 5th Ed.)

  • Reference year for utilities cost = 2018 (as of Turton et al. 5th Ed.)

• opex.SF - retrieves stream factor for plant operation

• opex.runtime - retrieves operational runtime per annum

• opex.shiftdur - retrieves duration of one workshift

• opex.shiftperweek - retrieves number of shifts per year

• opex.yearww - retrieves number of work weeks per year after leave entitlements

• opex.utilxxx - utility cost for xxx (USD/GJ basis), where xxx =

  • "HPS" for high-pressure steam (41 barg, 254 degC)

  • "MPS" for medium-pressure steam (10 barg, 184 degC)

  • "LPS" for low-pressure steam (5 barg, 160 degC)

  • "CW" for cooling water (30-45 degC)

  • "ChW" for chilled water (5 degC)

  • "LTR" for low temperature refrigerant (-20 degC)

  • "VLTR" for very low temperature refrigerant (-50 degC)

  • "elec" for electricity (110-440 V)

Functions:

• opex.operatorspershift - calculates # operators per shift

• opex.labourcost - calculates annualised labour cost

• opex.costofutil - calculates cost of utilities

• opex.costofmanfc - calculates all components of annualised total cost of manufacture (COM)