Tuesday, June 27, 2017: 8:00 AM-9:30 AM
Fundamentals and Applications
Chair:
Pradeep Bansal, Ph.D., ASHRAE STBE Editorial Board
There is a strong need to develop not-in-kind technologies to replace conventional vapor compression refrigeration technology that can improve the energy efficiency and environmental friendliness of residential and commercial building equipment. Such technologies will be critical to provide energy savings or other environmental benefits for space conditioning, water heating and refrigeration. This seminar presents material from three recently published papers from ASHRAE's archival journal, Science and Technology for the Built Environment, on the subject.
1 Compressor Driven Metal Hydride Heat Pumps Using Adsorptive Slurry and Isothermal Compression
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Nelson James, Purdue University
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James Braun, Ph.D., Purdue University
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Eckhard Groll, Dr.Ing., Purdue University
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Travis Horton, Ph.D., Purdue University
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Environmentally-friendly heat pumps operate using reversible adsorption and desorption of hydrogen from metallic compounds, which were incorporated in a cycle having a work input (compressor) or thermal energy input (generator). Some challenges faced by compressor-driven metal hydride heat pumps are poor heat transfer in the metal hydride beds and high compressor discharge temperatures. To overcome these challenges, a metal-hydride slurry in conjunction with various isothermal compression techniques were used. Liquid-flooded, electrochemical and liquid piston compressors were modeled and integrated into a system model in order to assess their impact on the performance of the slurry-based metal hydride heat pump system.
2 Design of a Hydraulically Driven Compressive Elastocaloric Cooling System
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Yunho Hwang, Ph.D., University of Maryland
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Suxin Qian, Ph.D., Xi’an Jiaotong University
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Yunlong Geng, Ph.D., University of Maryland
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Yi Wang, Ph.D., University of Maryland
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Jan Muehlbauer, University of Maryland
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Jiazhen Ling, Ph.D., University of Maryland
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Reinhard Radermacher, Ph.D., University of Maryland
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Ichiro Takeuchi, Ph.D., University of Maryland
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This paper presents the design of elastocaloric cooling system driven by hydraulic actuators. Ni-Ti tubes under axial compressive loading mode are used to provide cooling and heating. Those Ni-Ti tubes are enclosed in four identical beds, which are driven by two one-way hydraulic cylinders. Operated under the single-stage reverse Brayton cycle, the system achieves heat transfer and heat recovery by using a heat transfer fluid network controlled by solenoid valves. System coefficient of performance of 11.0 and temperature lift of 24.6 K are estimated based on a dynamic model developed in our previous study.
3 Design and Performance of a Novel Magnetocaloric Heat Pump
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Michael Benedict, Ph.D., General Electric
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S.a. Sherif, Ph.D., University of Florida
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Michael Schroeder, General Electric
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David Beers, General Electric
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This presentation covers an investigation into the design and preliminary results of a room temperature magnetic refrigeration prototype and describes the physical prototype along with its operational and measurement envelopes. General design goals included: A wide range of cycle parameter control, independent fluid and magnetic circuits, extensive measurement capability and compact design. The maximum no-load span recorded was 21 K and the maximum power recorded was 26 W at a span of 1 K. Three cyclical parameters were varied to help determine the optimal cycle for such a machine.
