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At least 451 records · Page 25

Development of Separate Sensible and Latent Cooling System Using Electrochemical Compressor

Separate sensible and latent cooling systems offer superior energy efficiency performance compared to conventional vapor compression air conditioning systems. In this paper we describe an innovative non-vapor compression system that uses electrochemical compressor (ECC) to pump hydrogen between 2-metal hydride reservoirs to provide the sensible cooling effect. The heat rejected during this process is used to regenerate the ionic liquid (IL) used for desiccant dehumidification. The overall system design is illustrated. The Xergy version 4C electrochemical compressor, while not designed as a high pressure system, develops in excess of 2 MPa (300 psia) and pressure ratios > 30. The projected base efficiency improvement of the electrochemical compressor is expected to be ~ 20% with higher efficiency when in low capacity mode due to being throttleable to lower capacity with improved efficiency. The IL was tailored to maximize the absorption/desorption rate of water vapor at moderate regeneration temperature. This IL, namely, [EMIm].OAc, is a hydrophilic IL with a working concentration range of 28.98% when operating between 25 75 C. The ECC metal hydride system is expected to show superior performance to typical vapor compression systems. As such, the combined efficiency gains from the use of ECC and separate and sensible cooling would offer significant potential savings to existing vapor compression cooling technology. A high efficiency Window Air Conditioner system is described based on this novel configuration. The system s schematic is provided. Models compared well with actual operating data obtained by running the prototype system. Finally, a model of an LiCl desiccant system in conjunction with the ECC-based metal hydride heat exchangers is provided.

Electrochemical Compression↗

Advanced metal hydride heat transfer system utilizing an electrochemical hydrogen compressor

An electrochemical heat transfer device for a hot water tank utilizes an electrochemical hydrogen compressor to pump hydrogen into and out of a tank having a metal hydride forming alloy therein. The absorption of hydrogen by the metal hydride forming alloy is exothermic, produces heat, and the desorption of the hydrogen from the metal hydride forming alloy is endothermic and draws heat in. An electrochemical hydrogen compressor may be configured between to tanks and pump hydrogen back and forth to form a heat transfer device, such as a hot water heater. A heat transfer device may be coupled with the tank or may comprise the outer surface of the tank to transfer heat to an object or to the surroundings. A closed loop may be configured having two tanks and one or two electrochemical hydrogen compressors to pump the hydrogen in a loop around the system.

Bahar, Bamdad↗

Advanced metal hydride heat transfer system utilizing an electrochemical hydrogen compressor

An electrochemical heat transfer device utilizes an electrochemical hydrogen compressor to pump hydrogen into and out of a reservoir having a metal hydride forming alloy therein. The absorption of hydrogen by the metal hydride forming alloy is exothermic, produces heat, and the desorption of the hydrogen from the metal hydride forming alloy is endothermic and draws heat in. An electrochemical hydrogen compressor may be configured between to reservoirs and pump hydrogen back and forth to form a heat transfer device. A heat exchange device may be coupled with the reservoir or may comprise the outer surface of the reservoir to transfer heat to an object or to the surroundings. A closed loop may be configured having two reservoirs and one or two electrochemical hydrogen compressors to pump the hydrogen in a loop around the system.

Bahar, Bamdad↗

Single-Stage Bunch Compressor for ILC-SB2009

The Project Management Design Team of the International Linear Collider has recently proposed fundamental changes to the published ILC RDR baseline with the goal of presenting a potential alternate design providing a more cost-effective solution. In this framework a new lattice for the Damping Rings has been presented, shortening the exit bunch length from the RDR value of 9 mm down to 6 mm. The shorter bunch length allowed the adoption of a simpler single-stage bunch compressor, instead of the RDR two-stage compressor. The new single-stage compressor has a compression ratio of 20 and still achieves the nominal RDR value of 0.3 mm bunch length at the Interaction Point. The new design has been optimized to generate the required compression while having a small SR emittance growth, and reduced energy spread. The new lattice and its optimization procedure are presented in this paper.

43 PARTICLE ACCELERATORS↗

Advanced metal hydride heat transfer system utilizing an electrochemical hydrogen compressor

An electrochemical heat transfer device utilizes an electrochemical hydrogen compressor to pump hydrogen into and out of a reservoir having a metal hydride forming alloy therein. The absorption of hydrogen by the metal hydride forming alloy is exothermic, produces heat, and the desorption of the hydrogen from the metal hydride forming alloy is endothermic and draws heat in. An electrochemical hydrogen compressor may be configured between to reservoirs and pump hydrogen back and forth to form a heat transfer device. A heat exchange device may be coupled with the reservoir or may comprise the outer surface of the reservoir to transfer heat to an object or to the surroundings. A closed loop may be configured having two reservoirs and one or two electrochemical hydrogen compressors to pump the hydrogen in a loop around the system.

Bahar, Bamdad↗

:investigation of a 24-inch Shock-in-rotor Type Supersonic Compressor Designed for Simple Radial Equilibrium Behind Normal Shock

A 24-inch-diameter shock-in-rotor supersonic compressor rotor designed to obtain simple radial equilibrium behind the normal shock obtained a maximum total-pressure ratio of 2.02 at an adiabatic efficiency of 0.74 and a weight flow of 61.5 pounds per second at design speed. Although this design method considerably reduced the radial forces, there was no apparent reduction in the radial forces, there was no apparent reduction in the radial redistribution of mass flow over the radial redistribution obtained in the previous investigation. This investigation indicates that the shock boundary-layer interaction pattern and associated effects have a very large effect on the radial redistribution of mass flow through the shock-in-rotor supersonic-compressor rotor.

FLOW, SUPERSONIC↗

Analysis of Off-design Performance of a 16-stage Axial-flow Compressor with Various Blade Modifications

The over-all performance of a 16-stage axial-flow compressor was determined with various stator-blade resettings and a reduction in solidity of the rotor blades in the last three stages. It was shown that little control over the sudden change in slope of the surge-limit line at intermediate speeds was obtained with the blade modifications attempted, except that some change in speed at which the change in slope occurred could be effected by stator-blade resettings. Interstage data indicated that the severe surge limit at intermediate speeds was caused by stall of the inlet stage, which, because of stage interaction effects, resulted in a simultaneous decrease in performance of the following five or six stages. Stage data are presented which indicate the flow and pressure-ratio range over which each stage is required to operate at compressor speeds from 50 to 100 percent of design speed.

COMPRESSORS - AXIAL-FLOW↗

Development and field demonstration of residential air source integrated heat pump using a three-stage compressor

To promote decarbonization and all electrification at residential sectors, it is necessary to use air source heat pumps (ASHPs) to replace natural gas for space heating and water heating. ASHPs are widely utilized for residential space cooling, heating, and water heating due to their simplicity and cost-effectiveness. However, their performance can be compromised in cold climates, where they may experience reduced heating capacity. A multi-functional heat pump, using a single compressor, to meet all home space conditioning and water heating demands, is an emerging technology. To address this limitation, we have developed and demonstrated an air source integrated heat pump to fulfill comprehensive home comfort requirements. This system employs a three-stage compressor and a single set of heat exchangers and valves, optimizing functionality while minimizing costs. The performance of the developed system was rigorously evaluated in both laboratory and field settings. In laboratory conditions, the system achieved a Seasonal Energy Efficiency Ratio of 17.0 (average COP of 4.98) and a Heating Seasonal Performance Factor of 11.0 (3.22). Additionally, in its most efficient operational mode—combining space cooling and water heating—the unit attained a total energy efficiency exceeding 7.0 seasonal COP in the field and could heat a 189-liter tank of water in just 25 min. The field study corroborated the laboratory findings, validating the system’s performance in real-world conditions. Here, this integrated heat pump represents an ideal solution for decarbonizing homes in northern climates by providing efficient space heating and water heating, thereby replacing the need for natural gas.

Integrated heat pump↗

A novel electron mirror pulse compressor

An electron mirror-based pulse compressor design has been developed for improving the temporal resolution of dynamic/ultrafast transmission electron microscopes and ultrafast electron diffraction cameras. The improvement will enable electron microscopes and diffraction cameras to better resolve the dynamics of reactions in the areas of solid state physics, chemistry, and biology. The design utilizes a combination of mirror optics and a magnetic beam separator, which exploits the symmetry inherent in reversing the electron trajectory in the mirror in order to compress the pulse. This system can also simultaneously correct the spherical and chromatic aberration of the objective lens for improved spatial resolution. For pulsed experiments with a practical bunch charge, the correction of the chromatic aberration coefficient counters the spread in the electron energies induced by the space charge of the pulse to make possible the probing of the sample with high spatial resolution. The pulse compressor can accommodate pulses with a range of electron densities and energy spreads. Additionally, it is designed to fit into both ultrafast electron diffraction cameras and dynamic/ultrafast transmission electron microscopes. Consequently, this instrument is suitable for enhancing the study of the structure, composition, and bonding states of new materials at ultrafast time scales.

47 OTHER INSTRUMENTATION↗

High efficiency, low frequency linear compressor proposed for Gifford-McMahon and pulse tube cryocoolers

In order to reduce the amount of greenhouse gas emissions, which are most likely the cause of substantial global warming, a reduction of overall energy consumption is crucial. Low frequency Gifford-McMahon and pulse tube cryocoolers are usually powered by a scroll compressor together with a rotary valve. It has been theoretically shown that the efficiency losses within the rotary valve can be close to 50%{sup 1}. In order to eliminate these losses we propose to use a low frequency linear compressor, which directly generates the pressure wave without using a rotary valve. First results of this development will be presented.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗

Control optimization of the cryoplant warm compressor station for EAST

The cryogenic control system for EAST (Experimental Advanced Superconducting Tokamak) was designed based on DeltaV DCS of Emerson Corporation. The automatic control of the cryoplant warm compressors has been implemented. However, with ever-degrading performance of critical equipment, the cryoplant operation in the partial design conditions makes the control system fluctuate and unstable. In this paper, the warm compressor control system was optimized to eliminate the pressure oscillation based on the expert PID theory.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗

Numerical simulations of output pulse extraction from a high-power microwave compressor with a plasma switch

Numerical simulations of the process of electromagnetic energy release from a high-power microwave pulse compressor comprising a gas-filled cavity and interference switch were carried out. A microwave plasma discharge in a rectangular waveguide H-plane tee was modeled with the use of the fully electromagnetic particle-in-cell code MAGIC. The gas ionization, plasma evolution, and interaction with RF fields accumulated within the compressor were simulated using different approaches provided by the MAGIC code: particle-in-cell approach accounting for electron-neutral collisions, gas conductivity model based on the concept of mobility, and hybrid modeling. The dependences of the microwave output pulse peak power and waveform on parameters that can be controlled in experiments, such as an external ionization rate, RF field amplitude, and background gas pressure, were investigated.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗

Alignment of chirped-pulse compressor

An original method of alignment of grating compressors for ultrahigh-power CPA laser systems is proposed. The use of this method for adjustment of the grating compressor of a PEARL subpetawatt laser complex made it possible to align the diffraction gratings with a second accuracy in all three angular degrees of freedom, including alignment of the grooves, and to adjust the angles of beam incidence on the grating with a high accuracy. A simple method for measuring the difference in the groove densities of gratings with accuracy better than 0.005 lines mm{sup -1} is proposed and tested. (control of laser radiation parameters)

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗

Shape optimization and fluid control of near isothermal compressor for transcritical carbon dioxide cycle

The compressor holds great promise for enhanced energy efficiency over a wide range of vapor compression systems (VCS). However, the majority of them focused on liquid refrigerant injection or inter-stage cooling technologies to improve heat transfer. Increasing the heat transfer area provides another perspective to promote heat dissipation, which commonly involves shape optimization whilst bringing some limitations, mainly from the manufacturing side. To fill the research gap, this paper compares the performance of isothermal compressors under different compression chamber shapes and chamber connection configurations. Additionally, the fluid control of the liquid piston was combined with shape optimization to explore the potential for further heat transfer enhancement. The simulation results have demonstrated that the COP improvements can reach up to 9% compared with the baseline case by optimizing the chamber shape and properly controlling the liquid piston speed, which provides a guideline for designing and customizing the isothermal compression chamber.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

A new type of bunch compressor and seeding of a short-wavelength coherent radiation.

Transverse-to-longitudinal emittance exchange was proposed in [1] as a tool for an effective matching of the electron beam phase space to requirements of a possible application. Here we propose a new purpose, namely, use of two consecutive emittance exchanges equipped with the telescope between them for a bunch compression that can be done without the energy chirp in the electron bunch. In principle it allows to reduce the electron peak current in the linac by moving the bunch compressor to the end of the linac and, thus, to relax collective effects associated with high peak currents. It is also possible to have a split-action compression when the first part is done inside the low-energy part of the linac and the second and final part is done after the linac. We also demonstrate how proposed bunch compressor can be used for frequency up-conversion of the energy modulation provided by the laser interacting with the electron beam and thus can prepare a significantly higher frequency seed for seeded free-electron lasers. The same approach can be used for a frequency down-conversion that can be useful for generation of THz radiation.

43 PARTICLE ACCELERATORS↗

Plasma Switch for High-Power Active Pulse Compressor

Results are presented from experiments carried out at the Naval Research Laboratory X-band magnicon facility on a two-channel X-band active RF pulse compressor that employed plasma switches. Experimental evidence is shown to validate the basic goals of the project, which include: simultaneous firing of plasma switches in both channels of the RF circuit, operation of quasi-optical 3-dB hybrid directional coupler coherent superposition of RF compressed pulses from both channels, and operation of the X-band magnicon directly in the RF pulse compressor. For incident 1.2 μs pulses in the range 0.63 - 1.35 MW, compressed pulses of peak powers 5.7 - 11.3 MW were obtained, corresponding to peak power gain ratios of 8.3 - 9.3. Insufficient bakeout and conditioning of the high-power RF circuit prevented experiments from being conducted at higher RF input power levels.

43 PARTICLE ACCELERATORS↗

High Efficiency Low Global Warming Potential Compressor

During this project UTRC designed a novel compressor for use with new low Global-Warming-Potential (GWP) refrigerants. Through two design and testing iterations, UTRC advanced the compressor technology from TRL3 to TRL5. The target application was a 5 Tons of Refrigeration (TR) capacity Roof-Top Unit (RTU), although this technology may be applied to other low-capacity systems such as residential. The prototype unit met all design goals at the ARI-A rating condition and requires high efficiency motor to meet high performance targets at the ARI-B condition. This technology may be used in high efficiency units and with seasonal energy efficiency rating (SEER) exceeding 20. A preliminary cost analysis estimated that there would be less than $25/kbtuh cost impact to the customer.

30 DIRECT ENERGY CONVERSION↗

High-Speed and Dynamic Diaphragm Compressor for High-Capacity Fueling (Final Technical Report)

Goal of the project is to scale the NEL hydrogen compressor technology from 1.1 kg/minute to 5.5 kg/minute capacity (scale 1:5). This will enable achievement of 330 kg/hour capacity, sufficient to achieve fast high-capacity heavy-duty vehicle (HDV) fueling. The technology readiness level (TRL) maturity objective is to develop and test a scaled-up compressor that is to advance from TRL3 to TRL7.

08 HYDROGEN↗