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Title Modifications to JLab 12 GeV Refrigerator and Wide Range Mix Mode Performance Testing Results
Authors Peter Knudsen, Venkatarao Ganni, Nusair Hasan, Kelly Dixon, Robert Norton, Jonathan Creel
JLAB number JLAB-PHY-16-2502
LANL number (None)
Other number DOE/OR/23177-6622
Document Type(s) (Meeting) 
Associated with EIC: No
Supported by Jefferson Lab LDRD Funding: No
Funding Source: Nuclear Physics (NP)

Invited Talk Paper compiled for 26th International Cryogenic Engineering Conference

Materials Science and Engineering
Edited By
IOP Publishing (2016)
Page(s) 171
Publication Abstract: Analysis of data obtained during the spring 2013 commissioning of the new 4.5-K refrigeration system at Jefferson Lab (JLab) for the 12 GeV upgrade indicated a wide capacity range with good efficiency and minimal operator interaction. Testing also showed that the refrigerator required a higher liquid nitrogen (LN) consumption for its pre-cooler than anticipated by the design. This does not affect the capacity of the refrigerator, but it does result in an increased LN utility cost. During the summer of 2015 the modifications were implemented by the cold box manufacturer, according to a design similar to the JLab 12 GeV cold box specification. Subsequently, JLab recommissioned the cold box and performed extensive performance testing, ranging from 20% to 100% of the maximum capacity, and in various modes of operation, ranging from pure refrigeration, pure liquefaction, half-and-half mix mode and at selected design modes. This testing demonstrated the modifications resulted in a LN consumption significantly lower than the expected design for the nominal and maximum capacity modes and equal to the expected design for the pure refrigeration mode (which is the most demanding). The testing also demonstrated that the refrigerator system has a good and fairly constant performance over this wide capacity range and different modes of operation. Also, a pulsed-load test, similar to what is expected for cryogenic systems supporting fusion experiments, was conducted to observe the response using the Floating Pressure ? Ganni Cycle, which was stable and robust. This paper will discuss the results and analysis of this testing pertaining to the LN consumption, the system efficiency over a wide range of capacity and different modes and the behavior of the system to a pulsed load.
Experiment Numbers:
Group: Cryogenics
Document: docx
Accepted Manuscript: Knudsen_2017_IOP_Conf._Ser.__Mater._Sci._Eng._171_012015.pdf
Supporting Documents:
Mod to JLab 12 GeV Refrigerator and Wide Range Mix Mode Performance Testing Results (8-O-1A-IT1).pdf (Supporting)
Supporting Datasets: