- Author
-
Chwalowski, M.
- Title
- Evaporator Performance Investigation for Residential Air-Conditioning Applications Using Mixed Refrigerants.
- Coporate
- National Institute of Standards and Technology, Gaithersburg, MD
- Sponsor
- Electric Power Research Inst., Palo Alto, CA
- Report
-
NISTIR 4723
November 1991
147 p.
- Distribution
- Available from National Technical Information Service
- Keywords
-
refrigerants
|
air-conditioning
|
effectiveness
|
evaporator
|
mixture
|
nonazeotropic
|
NTU
|
profile
- Abstract
- The design of the heat exchanger utilizing nonazeotropic refrigerant in an air conditioning application presents unique problems due to the phase change of the moist air and the variable specific heat of the evaporating refrigerant mixture. This study discusses the performance analysis and the design procedure of a cross counterflow heat exchanger working as an evaporator in an experimental system which simulated a residential air conditioning application. The effect of the change of the mixture composition on heat exchanger performance was evaluated. The focus of the theoretical study was the development of the effectiveness/NTU (epsilon/NTU) relationships with the use of the experimentally derived quantities for moist air flowing across the heat exchanger. Variable mixture specific heat, air and heat profiels obtained from the experimental results were utilized to obtain the expresion for epsilon/NTU. The derived epsilon/NTV relations were verified and found to be in good agreement with test results.