Dilution Refrigerators for Quantum Science
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HVAC systems account for approximately 14 Quads or primary energy annually, or nearly 30% of all energy used in the U.S. commercial and residential buildings. Electrochemical compression (ECC) is a transformative solid-state technology and ECC based HVAC systems could result in 40% less energy use. The goal of the project was to develop the most efficient, noiseless, and most environmentally friendly cooling system based on integrating 2 (two) technologies: a) electrochemical compressors (ECC) to replace mechanical compressors for use in building heating, ventilation, and air conditioning (HVAC) applications and b) Ionic Liquid Desiccant Systems. The overall objective was to develop and build a scalable ILD/ECC-based air conditioning system operating with a COP of 4.5, with a price premium of $70 installed per kBTU/hr.
Warehouses typically have a low energy use relative to their floor area. This make warehouses ideal to install solar panels and offset on-site energy use and have a surplus of energy if roof area is maximized. This surplus can be used to provide things like grid services or charge electric vehicle fleets. This document is intended to provide owners and operators of warehouse information on designing efficient/decarbonized warehouses and maximize on-site generation. The information here references outside publications to provide specific guidance, such as the ASHRAE Advanced Energy Design Guides, but tailors the information specifically to warehouses. This guide provides owners a better understanding of warehouse design as well as more specific information for themselves or outside designers to reference.
In this project, we studied the performance of the ammonia EC compressor under a variety of different conditions. We replicated preliminary data and using a small cell with 5 cm 2 of active area. We demonstrated the operation of larger cells with 100 cm 2 of active area. Further, we used a commercially available hydrogen EC compressor stack to analyze the scaled-up compressor performance. While previous experiments examined only the transient EC compressor performance, we developed test facilities that allowed the compressor to reach steady state.
Oak Ridge National Laboratory and Eck Industries produced and characterized durable and corrosion resistant Al-Ce-Mg alloy-based heat exchanger. Eck Industries successfully casted Al-Ce-Mg heat exchanger. ORNL characterized reaction bonding between Al-2Ce-6Mg alloy and stainless-steel tube in a heat exchanger header. Metallurgical bonds were achieved between stainless steel tubes and Al-Ce-Mg alloy cast headers. ORNL performed corrosion testing on Al-Ce-Mg alloy/stainless steel tube reactive bond interface. In most cases no significant changes to the reactive bond morphology or compositional distribution were observed in the samples after exposure to acid for 267h acid.
The purpose of this Cooperative Research and Development Agreement (CRADA) was to test a heat exchanger defrosting approach using radiant energy, including ultraviolet-C, -B, and -A. A preliminary test conducted at Oak Ridge National Laboratory demonstrated the concept of ultraviolet-based defrosting, which melts frost on the fin surface of a heat exchanger without increasing its overall temperature, thereby offering a new defrosting method that does not interrupt heat exchanger operation. Building on this key finding, this CRADA outlines a plan for upgrading the test equipment and for further testing to bridge the gap between the concept and its feasibility for industrial applications. This report also provides a brief review of existing defrosting technologies, the current state of the experimental system, and future parametric experiment plans.
The purpose of this Cooperative Research and Development Agreement (CRADA) was to test a heat exchanger defrosting approach using radiant energy, including ultraviolet-C, -B, and -A. A preliminary test conducted at Oak Ridge National Laboratory demonstrated the concept of ultraviolet-based defrosting, which melts frost on the fin surface of a heat exchanger without increasing its overall temperature, thereby offering a new defrosting method that does not interrupt heat exchanger operation. Building on this key finding, this CRADA outlines a plan for upgrading the test equipment and for further testing to bridge the gap between the concept and its feasibility for industrial applications. This report also provides a brief review of existing defrosting technologies, the current state of the experimental system, and future parametric experiment plans.
• Oak Ridge National Laboratory and Eck Industries produced and characterized durable and corrosion resistant Al-Ce-Mg alloy-based heat exchanger. • Eck Industries successfully casted Al-Ce-Mg heat exchanger. • ORNL characterized reaction bonding between Al-2Ce-6Mg alloy and stainless-steel tube in a heat exchanger header. • Metallurgical bonds were achieved between stainless steel tubes and Al-Ce-Mg alloy cast headers. • ORNL performed corrosion testing on Al-Ce-Mg alloy/stainless steel tube reactive bond interface. • In most cases no significant changes to the reactive bond morphology or compositional distribution were observed in the samples after exposure to acid for 267h acid.
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Knowledge of airborne particulate matter (PM), especially the particles that have supermicron diameters, is key for understanding ice-nucleating particles (INPs). Supported by the Atmospheric Radiation Measurement (ARM) user facility, we sampled PM and surface soil materials at the Southern Great Plains observatory (SGP; 36° 36′ 18″ N, 97° 29′ 6″ W) to systematically compare the INP abundance and ice nucleation efficiency of different SGP samples (i.e., airborne versus surface materials). The field campaign, named Examing INP from SGP II (ExINP-SGP II), was conducted from 20 January to 20 April, 2021. Our data analysis products include (1) physical surface sorption characterization data (i.e., BET, pore volume) of two sets of samples -- SGP Soil and USDA, (2) X-ray diffraction spectra for the same two samples, (3) immersion freezing assay-based ice nucleation active mass density data as a function of freezing temperature for both ambient and surface samples, and (4) time-series data of ambient meteorological conditions, concentration particle counter-derived aerosol particle concentration, and aerosol particle sizer measurement during ExINP-SGP II.
A process for removing a foulant from a gas stream. The gas stream is cooled in a series of heat exchangers, causing a portion of the foulant to desublimate and become entrained in a cryogenic liquid. This foulant slurry stream is pressurized, cooled, and separated into a pressurized foulant solid stream and the cryogenic liquid stream. The pressurized foulant solid stream is melted to produce a liquid foulant stream. Heat exchange processes, both internal and external, are provided that close the heat balance of the process. In this manner, the foulant is removed from the gas stream.
A heat exchanger system includes a heat exchanger coil circulating a first heat transfer fluid therethrough, and a fan at least partially surrounded by the heat exchanger coil to urge a flow of air through the heat exchanger coil to dissipate thermal energy from the first heat transfer fluid. A brushless direct current fan motor is located the fan to urge rotation of the fan and an ancillary electrical component operably connected to the heat exchanger system and electrically isolated from the first heat transfer fluid.
A process for removing a foulant from a gas stream is disclosed. The gas stream, containing a foulant, is cooled across a first heat exchanger and a second heat exchanger, producing a solid foulant entrained in cryogenic liquid as a foulant slurry, and a foulant-depleted gas stream. The foulant-depleted gas stream is passed through a cryogenic turbine and a first separation vessel, producing a light gas stream and further solid foulant. The solid foulants are recovered by a combination of pressurization, melting, and distillation to produce a liquid foulant product. Heat is recovered from the various streams in the various heat exchangers and the melter.
Pool boiling heat transfer is one of the most effective heat transfer methos and crucial for several energy conversion processes such as electronic cooling, steam generation, water purification and thermal management. Enhancing boiling heat transfer around the tubes enables higher heat flux, which can improve the efficiency and lead to compact heat exchangers. Delaying the onset of critical heat flux (CHF) allows for higher CHFs and protects equipment during anomalous transient conditions. Growing interest in process intensification and delayed CHF has motivated the current study. An experimental approach has been deployed to investigate a potential technique to enhance the pool boiling performance around small diameter tubes by open cell metal foams. The findings for nucleate pool boiling of Novec HFE 7000 on the externally enhanced and smooth tubes are reported. The enhanced tube comprised of compressed aluminum foam brazed around. All the samples were horizontally oriented, and the experiments were performed under ambient pressure conditions. The heat transfer measurements for the smooth tubes were compared with several existing correlations and established the baseline. The preliminary results showed that the aluminum foam effectively enhanced the heat transfer coefficient and delayed the onset of critical heat flux. In addition, the pool boiling process around the round tube sample was visualized from both side and front views to comprehend the heat transfer mechanisms underlying substantial enhancement observed during experiments.
A heat transfer device and method are disclosed. The device includes a working region (i.e., working substance) made from a first superconducting material having a superconducting state and a normal state when magnetized. The first superconducting material has a first energy gap while in the superconducting state. A substrate (i.e., cold reservoir) is connected to the working region at a first tunnel junction. The substrate may be a metallic substrate. A heat sink (i.e., hot reservoir) is connected to the working region at a second tunnel junction. The heat sink is made from a second superconducting material having a second energy gap that is larger than the first energy gap. In a particular example, the heat transfer device includes a metallic substrate is made from Copper, a working region made from Tantalum, a heat sink made from Niobium, and the first and second tunnel junctions are made from Tantalum Oxide.
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