University of Illinois Urbana-Champaign

Superheat control for air conditioning and refrigeration systems: Simulation and experiments

Otten, Richard J.

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Otten_Richard.pdf

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https://hdl.handle.net/2142/16787

Description

Title
Superheat control for air conditioning and refrigeration systems: Simulation and experiments
Author(s)
Otten, Richard J.
Issue Date
2010-08-20T17:57:50Z
Director of Research (if dissertation) or Advisor (if thesis)
Alleyne, Andrew G.
Department of Study
Mechanical Sci & Engineering
Discipline
Mechanical Engineering
Degree Granting Institution
University of Illinois at Urbana-Champaign
Degree Name
M.S.
Degree Level
Thesis
Date of Ingest
2010-08-20T17:57:50Z
Keyword(s)
  • control
  • superheat
  • air conditioning
  • refrigeration
  • Hardware in the Loop (HIL)
  • load emulation
  • feedforward
  • schedule
  • testing
  • space model
Abstract
Ever since the invention of air conditioning and refrigeration in the late nineteenth century, there has been tremendous interest in increasing system efficiency to reduce the impact these systems have on global energy consumption. Efficiency improvements have been accomplished through component design, refrigerant design, and most recently control system design. The emergence of the electronic expansion valve and variable speed drives has made immense impacts on the ability to regulate system parameters, resulting in important strides towards efficiency improvement. This research presents tools and methodologies for model development and controller design for air conditioning and refrigeration systems. In this thesis, control-oriented nonlinear dynamic models are developed and validated with test data collected from a fully instrumented experimental system. These models enable the design of advanced control configurations which supplement the performance of the commonly used proportional-integral-derivative (PID) controller. Evaporator superheat is a key parameter considered in this research since precise control optimizes evaporator efficiency while protecting the system from component damage. The controllers developed in this thesis ultimately provide better transient and steady state performance which increases system efficiency through low superheat set point design. The developed controllers also address the classical performance versus robustness tradeoff through design which preserves transients while prolonging the lifetime of the electronic expansion valve. Another notable contribution of this thesis is the development of hardware-in-the-loop load emulation which provides a method to test component and software control loop performance. This method alleviates the costs associated with the current method of testing using environmental test chambers.
Graduation Semester
2010-08
Permalink
http://hdl.handle.net/2142/16787
Copyright and License Information
Copyright 2010 Richard James Otten. All rights reserved.

Owning Collections

Graduate Dissertations and Theses at Illinois PRIMARY
Graduate Theses and Dissertations at Illinois
Dissertations and Theses - Mechanical Science and Engineering
Dissertations and Theses - Alleyne Research Group