Component 511: Inlet Conduit (Duct or Pipe) by HVACSIM+
General Description
In the Component 505 Conduit model, the inlet pressure is calculated
from the outlet pressure and the mass flow rate. In the Component 511 Inlet
Conduit model, the mass flow rate is calculated from the inlet and outlet
pressures. In all other respects, the two models are identical.
Nomenclature
K - flow resistance coefficient
DeltaP - inlet pressure minus outlet pressure
w - mass flow rate
Mathematical Description
Equation 1 in the Component 505 Conduit model is replaced by the
following equation:
w = sign(DeltaP)*(DeltaP/K)^0.5
Temperatures are calculated as described for the Component 505 Conduit model.
Component 511 Configuration
Inputs Description
1 Pi - inlet pressure
2 Po - outlet pressure
3 Ti - inlet temperature
4 Tamb - ambient temperature
5 To - outlet temperature
Outputs Description
1 To - outlet temperature
2 w - mass flow rate
Parameters Description
1 hi*A - inside surface heat transfer coefficient * area
2 ho*A - outside surface heat transfer coefficient * area
3 Cm - thermal capacitance of conduit material
4 V - volume of conduit
5 K - flow resistance coefficient
6 H - height of outlet above inlet
7 MODE - -2 => water, detailed dynamics (one D.E.)
-1 => air, detailed dynamics (one D.E.)
1 => air, simple dynamics (no D.E.)
2 => water, simple dynamics (no D.E.)
Reference:
1. HVACSIM+ Building Systems and Equipment Simulation Program Reference
Manual (NBSIR 84-2996)
Daniel R. Clark
United States Department of Commerce
National Institute of Standards and Technology
Gaithersburg, Maryland 20899-0001