Semi-empirical scroll compressor model with optional vapor-injection.

Number: 1200

Author(s) : CHRIST J., SCHMID F., STERGIAROPOULOS K., BERTSCH S.

Summary

The development and evaluation of heat pump system designs and control strategies is often based on simulative experiments on a virtual test rig. Such system simulations require component models of sufficient prediction precision while not being over-complex. One key component of every vapor compression heat pump is the compressor. This study presents a semi-empirical model of a scroll compressor with optional vapor-injection. The model predicts the electric power input and refrigerant mass flow as well as the hot gas temperature at the compressor’s discharge port. It is based on thermodynamic subprocesses covering refrigerant transitions. Important refrigerant mass flows, losses and heat transfers within the compressor are considered as well as its interaction with the surroundings. A set of parameters is used to adapt the generic model to a specific compressor. All parameters are derived based on data which is typically provided by compressor manufacturers in their catalogues or online tools. The parameters are determined via optimization. An important advantage of the proposed model is that the parameters are not purely empirical, but they have a physical significance. The optimization is monitored so that a global optimum is found. The model is then validated with multiple test cases.
The combination of a physically consistent generic model with empirically determined parameters of physical meaning has multiple advantages: A model for one specific compressor can be derived from information typically provided by manufacturers. Other than polynomial models, this model can be used for extrapolation, i.e., to predict compressor performance outside of the envelope of the data it was derived from. It can also be applied to test the use of new refrigerants which are not the design refrigerant.

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Pages: 10 p.

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Details

  • Original title: Semi-empirical scroll compressor model with optional vapor-injection.
  • Record ID : 30030282
  • Languages: English
  • Subject: Technology
  • Source: 2022 Purdue Conferences. 26th International Compressor Engineering Conference at Purdue.
  • Publication date: 2022/07/15

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