CH-03-08-3 -- Contribution of Heat Exchangers in Improved Performance of New Generation Automotive Air-Conditioning System with R-744 PDF

This paper describes results of a project to develop and compare the performance of a second-generation mobile R-744 air-conditioning system to the first mobile R-744 system tested by our group. An analysis of results obtained with the first-generation system indicated many possible areas of improvement. Thus, the impetus for constructing and subsequently testing the second-generation system was to demonstrate that significant gains in system performance were possible with enhanced system components.

Performance enhancements were achieved by introducing a superior compressor and improved heat exchangers. However, the most influential impact on improved performance was the introduction of a cross-counterflow gas cooler.

Results of tests at similar operating conditions, including compressor speed, show an 11% to 63% increase in evaporator capacity and a 1.6% to 6.3% increase in COP. Additional tests performed at similar conditions, high-side pressure, and/or evaporator capacity illustrate COP improvements of 7% to 75%.

Units: SI