07.01 Experimental Measurements


Using the NIST Webbook for Charts/Tables (uakron.edu, 14min) Shows how to access the NIST fluid properties as needed to design an OVC cycle. Demonstrates the procedure with a problem based on propane at -100F saturated vapor pressure being raised to 10 bars and 180F in an adiabatic compressor by solving for the compressor efficiency and the COP.

Comprehension Questions:

1. Chlorodifluoromethane is used as the working fluid of an OVC cycle at -100F saturated vapor pressure exiting the evaporator and 80F saturated liquid exiting the condenser. Assuming an adiabatic reversible compressor solve for the COP.

Experimental observation of the critical point (LearnChemE.com, 5min) Discusses the background of the critical point and its relation to the 2-phase envelope. Includes a video showing the transition of a 2-phase fluid as it is heated through the critical temperature, then cooled back again.

Comprehension Questions:

1. Based on watching the video, what is different about the behavior of the fluid when it is cooled through the critical point as opposed to being heated from subcritical to supercritical?