|Title:||Dynamic Modeling And Control of Single and Multi-Evaporator Subcritical Vapor Compression Systems
|Author(s):||Shah, R.; Alleyne, Andrew G.; Bullard, C.W.; Rasmussen, Bryan P.; Hrnjak, P.S.
|Subject(s):||vapor compressor systems
|Abstract:||The focus of this research is on the development of a dynamic modeling capability for subcritical vapor
compression systems with one or more evaporators. The modeling methodology is developed with the multiple
objectives of prediction, control and design.
Firstly, the individual component models for a typical subcritical cycle are developed based on the best
published theoretical and empirical literature. Modeling methodology for a general multi-evaporator system follows
this discussion. The approach developed, especially for air conditioning systems, is conceptually new and can be
used with modifications to a variety of multi-component system applications. The component models are then
integrated and the model predictions validated against the data from various experimental test systems.
Secondly, the dynamic analysis of the model suggests the presence of a few fast dynamic modes. The
model reduction was conducted and the reduced order model was used as a basis for the design of a multivariable
adaptive controller for performance and efficiency control of a single evaporator system. Furthermore, the physicsbased
nonlinear component models can be linearized about a set point to obtain a linear model for the integrated
system. A complete linear model was developed and used for the design of a model based control of a dual
evaporator vapor compression cycle. Both these control schemes showed good results on implementation on the
validated system models.
Thirdly, the component models developed in this research were used to simulate the system response to
varying component parameters. This was done to demonstrate the efficacy of the modeling structure for system
design based on a desired response.
The primary objectives of prediction, control and design are met to a good extent by the work presented in
this research. Furthermore, the results and methodologies are modular for use in a variety of applications including
transcritical vapor compression systems also.
|Publisher:||Air Conditioning and Refrigeration Center. College of Engineering. University of Illinois at Urbana-Champaign.
|Series/Report:||Air Conditioning and Refrigeration Center TR-216
|Sponsor:||Air Conditioning and Refrigeration Project 123
|Date Available in IDEALS:||2009-06-12