Vapor Compression

Air Conditioning and Climate Control Design

SINDA/FLUINT and FloCADĀ® are used in automotive climate control, electronics cooling, and building HVAC design to simulate transient operation of vapor compression (VC) cycles and for the prediction of pressures, coefficients of performance, and condenser/evaporator liquid positions in a closed two-phase system with a fixed fluid charge. The programs can also be used to size components, to estimate the impact of tolerances and other variations, and to help estimate uncertainties given limited test data.

This widespread application of FloCAD to VC cycles is largely due to an increased demand for transient modeling of air conditioning systems needed to improve energy efficiency. FloCAD's unique abilities to analyze transient two-phase phenomena have been recognized as being critical to achieving accurate performance predictions. It also has tools to deal with the complexities of capillary tubes (both steady and transient) and suction line heat exchangers (SLHX).

A key advantage of using FloCAD to model VC cycle air conditioners is that it is not written specifically to address such systems: the general-purpose nature of the code can be exploited to integrate the VC cycle model with detailed models of the application (vehicle, building, electronics cabinet, etc.).

Sample Models:

Applications in this field have included:
Results of Transient Air Conditioning Prediction

  • Component modeling (compressor, evaporator, heat exchangers, heat pump, condenser, throttling devices)
  • Tracking of charge for steady state and transient simulation
  • Cabin/room psychrometrics and venting
  • System pressure prediction
  • Parametrical analysis and design optimization for sizing of compressors and heat exchangers
  • Effects of time- and direction-varying body forces
  • Regenerative interconnections such as SLHX


Recorded Videos