Browse Publications Technical Papers 1999-01-0583

The Role of Suction Line Heat Exchanger in Transcritical R744 Mobile A/C Systems 1999-01-0583

Transcritical R744 systems are under consideration for use in mobile air conditioning. Experimental results indicate that the inherent thermodynamic shortcomings of R744 could be overcome by exploiting inherent advantages in transport properties, pressure drop, and other characteristics. This paper describes one possible way to improve both capacity and energy efficiency of the R744 system for the car air conditioning. It considers the use of a suction line heat exchanger. Four different configurations of the prototype system were tested: without heat exchanger, and with three coaxial heat exchangers having lengths 1.0, 1.5 and 2.0m. All heat exchangers were made from identical pipes.
Results show that both the capacity and the coefficient of performance could be increased by up to 25%. Greater influence is registered at the higher temperatures of the air to the gas cooler.
The results also demonstrate the extent to which suction line heat exchangers can increase compressor discharge temperatures, thereby complicating the task of compressor design and introducing reliability risks.


Subscribers can view annotate, and download all of SAE's content. Learn More »


Members save up to 43% off list price.
Login to see discount.
Special Offer: With TechSelect, you decide what SAE Technical Papers you need, when you need them, and how much you want to pay.