Variable refrigerant flow heat pump model with estimated parameters and emulated controller based on manufacturer data

Abstract

A new physics-based and modular variable refrigerant flow (VRF) heat pump model aimed toward multi-year simulations is presented. The model allows the simulation of any number of indoor units (IU), outdoor units (OU) and compressors. A parameter-estimation procedure and a control strategy both using available manufacturer data is proposed. The model is validated against data collected from a VRF system that services the first floor of the former ASHRAE Headquarters Building in Atlanta (USA), comprised of 22 IU, 2 OU, and 8 compressors. Results show that the model accurately predicts the total energy consumption over a two-month cooling period, with a relative error, normalized mean bias error, and coefficient of variation of the root mean square error of 1%, 1.6%, and 16.7%, respectively.

Acknowledgment

The authors also acknowledge the support of the NSERC, the Trottier Energy Institute and Hydro-Québec for scholarships awarded to the first author. This study leveraged measured data kindly provided by Dr. Jeffrey Spitler and Laura Southard, for which the authors are deeply appreciative.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

The authors received the support of the Natural Sciences and Engineering Research Council of Canada (NSERC), [funding reference number RGPIN-2018-04471].