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Apparatus Dew Point #1

Open ThibaultMarzullo opened 3 years ago

ThibaultMarzullo commented 3 years ago

See related issue in MODRLC: https://github.com/henze-research-group/MODRLC/issues/5#issue-802727039

ThibaultMarzullo commented 3 years ago

The issue could be related to another problem when setting the nominal parameters and performance curves for the CC. This is what happens in Dymola when it is set to replicate the .idf file's CC:

Warning: The following was detected at time: 0
  *** Warning: In DX coil model, gamma is too large for these coil conditions.
    Instead of gamma = 1.5, a value of -0.892027, which
    corresponds to a mass transfer effectiveness of 0.8, will be used.
    Coil nominal performance data are:
    nomVal.m_flow_nominal = 0.55
    dX_nominal = XEvaOut_nominal-XEvaWetBulOut_nominal = 0.0124652 - 0.0109999 = 0.0014653
    QLat_flow_nominal  = -1807.66
  Failed condition: mod.HVAC.sinSpeDX.eva.nomVal.gamma <= mod.HVAC.sinSpeDX.eva.gammaMax
ThibaultMarzullo commented 3 years ago

Gamma is constrained by gammaMax with: gammaMax = 0.8 * nomVal.m_flow_nominal * dX_nominal * h_fg / QLat_flow_nominal; and 0 < gamma <= gammaMax If we look at the rest of the equation and parameter declarations: dX_nominal must be positive; h_fg is positive; QLat_flow_nominal must be negative; m_flow_nominal is not constrained but crashes the simulation if it is set to a negative; gammaMax must be positive. There is a sign problem.