Example 08b: Humidification: As a 2-step (3-state) process

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Tutorial
TRAIL: Air Conditioning Psychrometrics (vs CED Engineering course): Example results (only) in Mathematica and SysML using the Webel Psy package and MPsy class
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Topic level
BASIC
Keywords
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plot
table
Example problem from:
CED Engineering course PDF: 'Air Conditioning Psychrometrics (A.Bhatia)'
Example question (in abbreviated form):
Ninety cubic-ft of lumber is dried at 140°F 'tdb' and 125.6°F 'twb'. The drying rate of the lumber is 5.68 lb of water per hour. If outside air is at 80.6°F 'tdb' and 80% relative humidity how much outside air is needed per min to carry away the moisture?
There is an error in the statement of the dry bulb temperature (claims is 100°F) and the relative humidity (claims is 39.6%) at intermediate State0 (Node0) between State1 and State2 in the course PDF worked solution
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Following on from the previous example, the humidification process is represented here using Webel MPsy objects as a two-step (three state) process, a sensible heating without water content change from State1 to an intermediate "State0", then a humidification change to State2.

Note how the dry bulb temperature 'tdb' of the object for State0 is taken from the 2nd (final) State2, whereas the humidity ratio 'w' of the object for the "intermediate" State0 is taken from the 1st (initial) State1.

Up next
Example 09: Moisture added to air: Amount (mass)
Notes
[COMPLICATION, GOTCHA, TIP]{INFORMATIVE} GOTCHA: Mathematica: Specific enthalpy conversion J/kg to Btu/lb: Does not consider a possible "total" enthalpy reference offset vs 0 °C or 0 °F respectively
[CONVENTION]{STRICT} Webel: Psy/MPsy: Psychrometrics for Mathematica: For Imperial Units (IP), International British Thermal Units (Btu) are assumed
[ASSERTION, GOTCHA, WARNING]{INFORMATIVE} In the course PDF for 'CED Engineering: Air Conditioning Psychrometrics (A.Bhatia)' the term "enthalpy (h)" usually refers to the mass-specific enthalpy per dry air (in CoolProp notation 'Hda')
[CONVENTION]{STRICT} Webel: Psy/MPsy: Psychrometrics for Mathematica: Transferred heat (energy "Q") has field names with lower case 'qTot', 'qSen', 'qLat'. Heat rates (energy per time) have field names 'qDotTot', 'qDotSen', 'qDotLat' (to avoid clashes with Mathematica core)
Snippets (quotes/extracts)
 Ninety cubic-ft of lumber is dried at 140°F 'tdb' and 125.6°F 'twb'. The drying rate of the lumber is 5.68 lb of water per hour. If outside air is at 80.6°F 'tdb' and 80% relative humidity how much outside air is needed per min to carry away the moisture?
 Heat released by a system into its surroundings is by convention a negative quantity (Q < 0); when a system absorbs heat from its surroundings, it is positive (Q > 0).
Visit also
CED Engineering course PDF: 'Air Conditioning Psychrometrics (A.Bhatia)'
Visit also (backlinks)
Related slides (includes other tutorials)
Related slides (backlinks, includes other tutorials)
SysML4Mathematica: Example 08a: Humidification: Drying lumber with air: required volumetric air flow rate