The Integral Vapor Compression and Liquid Coolant Refrigeration System

This paper describes a unique refrigeration system that has been developed by McDonnell Aircraft Company. This refrigeration system, known as the Integral Vapor Compression and Liquid coolant (IVCL) system, operates on an innovative thermodynamic cycle that combines refrigeration and liquid coolant heat transport functions.

Activities conducted to date on this system include both analytical and empirical investigations. The analytical investigations have consisted of examining the thermodynamics of the new cycle to verify its technical feasibility, and comparing its operating characteristics to those of the conventional mechanical vapor compression refrigeration cycle. Empirical investigations have involved experiments to determine the miscibility of various refrigerant and liquid coolant combinations, testing of mixer and separator configurations, and operation of a complete, small-scale IVCL system demonstrator. Based on the results of these activities, the following conclusions have been drawn:

1. 1.
   The IVCL refrigeration system is technically feasible, as has been demonstrated both theoretically and in the laboratory.
2. 2.
   When operating with low heat sink flow rates the IVCL system's Coefficient of Performance (COP) and maximum attainable heat sink temperature are significantly greater than those of a comparable mechanical vapor compression cycle refrigeration system.
3. 3.
   As the heat sink flow rate is increased a conventional vapor cycle system's COP and maximum heat sink temperature continue to improve, while the IVCLs' only improve some what, and then remain constant. At very high flow rates the vapor cycle system provides greater COP and maximum attainable heat sink temperature than does the IVCL system.
4. 4.
   The IVCL system's superior performance at low heat sink flow rates can provide major benefits in terms of improving tactical aircraft thermal management.