Dynamic Modeling And Control of Single and Multi-Evaporator Subcritical Vapor Compression Systems

Shah, R.; Alleyne, Andrew G.; Bullard, C.W.; Rasmussen, Bryan P.; Hrnjak, P.S.

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https://hdl.handle.net/2142/12171 Copy

Description

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.

Issue Date

2003-08

Keyword(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 Name or Number

Air Conditioning and Refrigeration Center TR-216

Type of Resource

text

Language

en

Permalink

http://hdl.handle.net/2142/12171

Sponsor(s)/Grant Number(s)

Air Conditioning and Refrigeration Project 123

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