Browse Air Conditioning and Refrigeration Center Technical Reports by Author "Bullard, C.W."

  • Malik, T.; Bullard, C.W. (Air Conditioning and Refrigeration Center. College of Engineering. University of Illinois at Urbana-Champaign., 2004-06)
    HEVs idle their engine during the stops to meet the cooling and heating needs. But, idling decreases fuel economy and increases engine wear and emissions. The report explores alternative strategies for air conditioning ...
    untranslated PDF (785KB)
  • Poort, M.J.; Bullard, C.W. (Air Conditioning and Refrigeration Center. College of Engineering. University of Illinois at Urbana-Champaign., 2005-05)
    Rapid cycling of the compressor can be used to modulate capacity as an alternative to variable speed a/c and refrigeration systems. This paper outlines design recommendations to optimize rapid cycling performance based on ...
    untranslated PDF (1MB)
  • Rubas, P.J.; Bullard, C.W. (Air Conditioning and Refrigeration Center. College of Engineering. University of Illinois at Urbana-Champaign., 1993-07)
    Thermal mass effects, refrigerant dynamics, and interchanger transients are three factors affecting the transient and cycling performance of all refrigeration and air conditioning equipment. The effects of refrigerant dynamics, ...
    untranslated PDF (623KB)
  • Jain, S.; Bullard, C.W. (Air Conditioning and Refrigeration Center. College of Engineering. University of Illinois at Urbana-Champaign., 2004-05)
    Air conditioning and refrigeration systems are designed to meet the load at some particular design conditions. At off-design conditions, the compressor is either cycled or a variable speed drive enables the compressor ...
    untranslated PDF (801KB)
  • Rasmussen, B.P.; Shah, R.; Musser, A.B.; Alleyne, Andrew G.; Bullard, C.W.; Hrnjak, P.S.; Miller, N.R. (Air Conditioning and Refrigeration Center. College of Engineering. University of Illinois at Urbana-Champaign., 2002-10)
    This thesis details the efforts to develop a dynamic model of a transcritical vapor compression system suitable for multivariable control design purposes. The modeling approach is described and the developed models are ...
    untranslated PDF (3MB)
  • Andrade, M.A.; Bullard, C.W. (Air Conditioning and Refrigeration Center. College of Engineering. University of Illinois at Urbana-Champaign., 1999-07)
    Residential-scale ale systems control indoor temperature but not humidity. The advent of variable-speed compressors and blowers make such control possible. This paper uses a detailed simulation model to explore the ...
    untranslated PDF (2MB)
  • Krause, P.E.; Bullard, C.W. (Air Conditioning and Refrigeration Center. College of Engineering. University of Illinois at Urbana-Champaign., 1994-07)
    The cycling losses of a domestic refrigerator-freezer are quantified to gain a better understanding of the adjustments needed to enable a steady-state refrigerator model to be used to design for cycling operation. ...
    untranslated PDF (887KB)
  • Carlson, D.M.; Hrnjak, P.S.; Bullard, C.W. (Air Conditioning and Refrigeration Center. College of Engineering. University of Illinois at Urbana-Champaign., 2001-06)
    Frost deposition across a typical eight-row deep refrigeration display case heat exchanger was studied under varying conditions of face velocity, refrigerant temperature glide, and absolute humidity. The heat exchanger, ...
    untranslated PDF (8MB)
  • Peixoto, R.A.; Bullard, C.W. (Air Conditioning and Refrigeration Center. College of Engineering. University of Illinois at Urbana-Champaign., 1994-02)
    untranslated PDF (1MB)
  • Verma, P.; Bullard, C.W.; Hrnjak, P.S. (Air Conditioning and Refrigeration Center. College of Engineering. University of Illinois at Urbana-Champaign., 2002-10)
    A simulation model for predicting the performance of a display case under frosting conditions has been developed. An experimentally validated heat exchanger simulation model for a secondary refrigerant was extended to ...
    untranslated PDF (595KB)
  • Kulkarni, T.; Bullard, C.W. (Air Conditioning and Refrigeration Center. College of Engineering. University of Illinois at Urbana-Champaign., 2003-02)
    The present work is based on theoretical and computational investigations into microchannel heat exchangers. Microchannel heat exchangers have long been used as condensers but concerns regarding refrigerant maldistribution ...
    untranslated PDF (466KB)
  • Uribe, T.; Bullard, C.W.; Hrnjak, P.S. (Air Conditioning and Refrigeration Center. College of Engineering. University of Illinois at Urbana-Champaign., 2003-12)
    The purpose of this project is to explore the system design implications of compressor rapid cycling. An earlier project yielded promising results for a typical 2-ton residential split system. It showed that cycle periods ...
    untranslated PDF (4MB)
  • Bullard, C.W.; Davidson, I.E. (Air Conditioning and Refrigeration Center. College of Engineering. University of Illinois at Urbana-Champaign., 2006-09)
    This report analyzes a broad spectrum of strategies for actively or passively controlling the inlet state of fixed-geometry expansion devices such as capillary and orifice tubes, to match compressor mass flow rates ...
    untranslated PDF (1MB)
  • Mullen, C.E.; Bridges, B.D.; Porter, K.J.; Hahn, G.W.; Bullard, C.W. (Air Conditioning and Refrigeration Center. College of Engineering. University of Illinois at Urbana-Champaign., 1997-04)
    Component submodels for a room air conditioner computer simulation were developed and validated using data from a 1.5-ton room air conditioner. The room air conditioner was tested over an extremely wide range: both indoor ...
    untranslated PDF (2MB)
  • Woodall, R.J.; Bullard, C.W. (Air Conditioning and Refrigeration Center. College of Engineering. University of Illinois at Urbana-Champaign., 1996-06)
    This report describes the further development and validation of the Refrigerator/Freezer Simulation (RFSIM) model. The reports also describes the first major application of the model as an analysis tool for new refrigerator ...
    untranslated PDF (18MB)
  • Kelman, S.; Bullard, C.W. (Air Conditioning and Refrigeration Center. College of Engineering. University of Illinois at Urbana-Champaign., 1999-01)
    The primary focus of this thesis is on performance advantages of a dual-temperature evaporator refrigerator system over a conventional design. Through extensive use of computer-aided modeling, it is demonstrated that ...
    untranslated PDF (8MB)
  • Shah, R.; Alleyne, Andrew G.; Bullard, C.W.; Rasmussen, Bryan P.; Hrnjak, P.S. (Air Conditioning and Refrigeration Center. College of Engineering. University of Illinois at Urbana-Champaign., 2003-08)
    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 ...
    untranslated PDF (3MB)
  • Kirby, E.S.; Bullard, C.W.; Dunn, W.E. (Air Conditioning and Refrigeration Center. College of Engineering. University of Illinois at Urbana-Champaign., 1997-07)
    A 1.5 ton window air conditioner was extensively instrumented and tested over a wide range of wet- and dry-coil operating conditions. The results were used to improve a steady-state simulation model. Published air- and ...
    untranslated PDF (5MB)
  • Cavallaro, A.R.; Bullard, C.W. (Air Conditioning and Refrigeration Center. College of Engineering. University of Illinois at Urbana-Champaign., 1994-07)
    Air-side heat transfer correlations were developed to describe variable conductance models for the condenser and evaporator. Few experimentally estimated parameters described well the changes of refrigerant and air-side ...
    untranslated PDF (482KB)
  • Pira, J.V.; Bullard, C.W.; Jacobi, A.M. (Air Conditioning and Refrigeration Center. College of Engineering. University of Illinois at Urbana-Champaign., 2000-08)
    This report describes analyses aimed at integrating component optimization and system design by developing heat-exchanger performance evaluation criteria (PEC) that account for the system-level performance impacts of ...
    untranslated PDF (7MB)