Development of a Carbon Dioxide-Based Field Deployable Environmental Control Unit to Replace HCFC-22 or HFC-134a Units.

摘要

This document reports on the design, construction, and testing of a piston-cylinder type expansion device with output work (ED-WOW) to be used in a transcritical carbon dioxide air conditioning system that is intended to replace R-22-based or R-134a-based Field Deployable Environmental Control Units (FDECUs) . The ED-WOW is based on a highly modified small four-cycle, two-piston engine with a displacement of 2 x 13.26 cu cm that is commercially available. The ED- WOW replaced the expansion valve in an experimental transcritical CO2 cycle and increased the system performance by up to 10%. In addition, this document reports on the development of simulation models for the ED-WOW as well as for the transcritical CO2 cycle. The ED-WOW model was used to verify the proper operation of the device in the prototype application and to identify the major losses of the device. The model can be used to re-design the next generation ED- WOW. The cycle model was used to predict the performance of several modifications to the transcritical CO2 cycle and identify which modification is most suitable for implementation in a carbon dioxide-based FDECU.