Not-in-kind cooling technologies: A quantitative comparison of refrigerants and system performance

Qian, Suxin; Nasuta, Dennis; Rhoads, Adam; Wang, Yi; Geng, Yunlong; Hwang, Yunho; Radermacher, Reinhard; Takeuchi, Ichiro

doi:10.1016/j.ijrefrig.2015.10.019

Cited by 164 publications

(75 citation statements)

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“…To quantify the EC performance of SMAs while accounting for W, the following index of the material-based 31 The arrows in a indicate the crossover temperatures (T CO ) of − Q and W, which are identical to the temperatures at which − ΔT ad eff crosses zero in c. In these figures, the curves for Cu-based SMA were derived from the specific heat measurements for Cu-Al-Mn ( Supplementary Figure S4c Cryogenic superelasticity with large elastocaloric effect K Niitsu et al coefficient of performance (COP mat ) for isothermal conditions 39 was used:…”

Section: Resultsmentioning

confidence: 99%

Cryogenic superelasticity with large elastocaloric effect

et al. 2018

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Shape-memory alloys suitable for low-temperature environments are crucially lacking despite their potential applications for aerospace engineering, superconducting technologies, and liquefied-gas-storage technologies. Even for benchmark shape-memory alloys such as Ti-Ni and Ni-based Heusler alloys, superelasticity becomes appreciably difficult to achieve upon cooling because of a drastic increase in stress hysteresis. Here, we report a superelastic strain of more than 7% for a Cu-Al-Mn shape-memory alloy down to 4.2 K with stress hysteresis as small as that at ambient temperature. Furthermore, the transformation entropy change remains as large as that at ambient temperature down to~50 K. Consequently, an excellent elastocaloric cooling property is simultaneously obtained even at cryogenic temperatures, at which existing shape-memory alloys lose this property because of decreased entropy change and increased stress hysteresis. The developed cryogenic superelastic alloy shows excellent potential as a new class of material combining superelastic properties with sufficiently small dissipated energy and persistent elastocaloric cooling ability even in cryogenic environments.

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Section: Resultsmentioning

confidence: 99%

Cryogenic superelasticity with large elastocaloric effect

et al. 2018

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“…[7]. It does not include the system details such as limitations in the driving system efficiency (from compressor, motor, etc.…”

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confidence: 99%

“…The latter is a vector field describing the electrical effect of free and bound charges in materials. Compared to VCR, the E plays the role of pressure and D plays the role of volume in vapour compression.More detailed descriptions can be found in a number of recent reviews of the EC effect [2,4,5] and its application in refrigerators [3,6,7], and a book on this topic [8]. …”

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Electrocaloric Cooling

Suchaneck¹,

Pakhomov²,

Gerlach³

2017

Refrigeration

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The electrocaloric effect describes a reversible temperature change in dielectric materials submitted to an applied electric field. Adiabatic polarization raises their temperature, and adiabatic depolarization lowers it, analogous to temperature changes that occur when a gas is compressed or expanded. For refrigerator application, the reverse Brayton cycle is currently the most promising for practical implementation. The electrocaloric effect provides a large material efficiency. However, existing refrigerator prototypes lack from the absence of efficient heat switches for thermal linkage to the load and the heat sink. Cooling power densities of a few W/cm 2 and temperature spans in the order of 20 K (in regeneration systems) are achievable at a cycle time of 100 ms.Keywords: electrocaloric effect, thermodynamic cycles, coefficient of performance, refrigeration devices IntroductionFor almost 150 years, refrigeration applications were solved by means of vapour compression. While the most efficient fluids for this approach are based on chlorofluorocarbons, hydrochlorofluorocarbons and hydrofluorocarbons, they come with the severe drawback of contributing to global warming and ozone depletion. Therefore, in 1987, the Montreal Protocol issued a ban on these chemicals providing regulations for phasing them out. Promising natural alternative substances are impractical due to their toxicity (ammonia) or-in particular-their flammability (propane) [1].Vapour compression refrigerators (VCRs) are operated as reverse Rankine cycles. They use a circulating liquid refrigerant as a medium. The refrigerant is: (i) adiabatically compressed, (ii) condensed at constant pressure undergoing a phase transition (thereby rejecting heat to the heat sink), (iii) adiabatically throttled in an expansion valve and (iv) evaporated at constant © 2017 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.pressure undergoing the reverse phase transition (thereby absorbing heat from the load). The amount of transferred heat is determined by the latent heat of the first-order phase transition. Similarly, in solid-state electrocaloric (EC) cooling, the adiabatic compression/expansion of the refrigerant is analogous to adiabatic polarization/depolarization, while the isobaric processes are replaced by isofield ones. Contrary to VCR, where the adiabatic expansion of the vapour is thermodynamically irreversible, the EC and the magnetocaloric (MC) effects are thermodynamically reversible processes that could reach the limit of the Carnot efficiency. This is another aspect making them promising for future application.Electric fields required for the EC refrigeration cycle can be supplied much easier and less expensively than the high magnetic fields required for the MC refrigeration [2]. Other advantages in compar...

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“…As tecnologias conhecidas como "Not-in-kind" (NIK), são uma potencial alternativa para a economia de energia, assim como apresentam benefícios ao meio ambiente (Bansal et al, 2012;Qian et al, 2016). Bansal et al (2012) apontam no mesmo estudo que a refrigeração termoelétrica e magnética são as principais tecnologias emergentes neste campo.…”

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Estudo Comparativo Entre Refrigeração Magnética E Refrigeração Por Compressão De Vapor

CARVALHO¹

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Comparative study between magnetic refrigeration and vapor compression refrigerationMagnetic refrigeration is an emerging technology with a great potential of growth, which can substitute, in future, the traditional technology of vapor compression. The refrigerants used by the magnetic refrigerator are not harmful to environment, since they have no Ozone Depletion Potential (ODP) or Global Warming Potential (GWP).This technology exploits the magnetocaloric effect, an intrinsic property of certain materials. This effect is observed in the adiabatic magnetization and demagnetization of the material, with the purpose of creating a temperature differential. The regenerator is composed by this material, and is submitted to four distinct process: magnetization, cold blow, demagnetization and hot blow. This four process, constituting what today is known by active magnetic regenerator cycle, which simulates the Brayton cycle.A device is proposed formed by the gadolinium regenerator , two heat exchangers (a cold and hot one) and a displacer. The device simulates a heat pump, which uses the magnetocaloric effect to create a temperature gradient in the regenerator, so that it can heat or cool the working fluid which exchanges heat at both heat exchangers.An unidimensional model is developed to simulates this device. The principal objective of this work is predict the temperature behaviour across the regenerator, the cooling capacity and the COP of the device. A parameter known as utilization factor is investigated to measure the system efficiency, and how to define this factor is important to improve the device efficiency.A direct comparison between the magnetic refrigeration and vapor compressor refrigeration technologies is carried out. The main parameters for this analysis are: cooling capacity, cost and size.

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Not-in-kind cooling technologies: A quantitative comparison of refrigerants and system performance

Cited by 164 publications

References 54 publications

Cryogenic superelasticity with large elastocaloric effect

Cryogenic superelasticity with large elastocaloric effect

Electrocaloric Cooling

Estudo Comparativo Entre Refrigeração Magnética E Refrigeração Por Compressão De Vapor

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