A comparison between experimental and 2D numerical results of a packed-bed active magnetic regenerator

Aprea, Ciro; Cardillo, Gerardo; Greco, Adriana; Maiorino, Angelo; Masselli, Claudia

doi:10.1016/j.applthermaleng.2015.07.020

Cited by 55 publications

(23 citation statements)

References 31 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The equations that model the adiabatic field increase/decrease processes are: They must include caloric effect which increases or decreases the temperature of the solid by the variation of the external field applied to the regenerator. Hence the adiabatic temperature variation ΔTad is converted into a heat source Q as: Q has the dimensions of a power density and it is included in the solid energy equation [44]. It is positive during field increase, negative during field decrease.…”

Section: Methodsmentioning

confidence: 99%

A comparison between different materials with mechanocaloric effect

Aprea¹,

Greco²,

Maiorino³

et al. 2018

IJHT

Self Cite

View full text Add to dashboard Cite

Caloric refrigeration can be a viable alternative to the traditional vapour compression technology since a caloric solid refrigerant has zero vapour pressure and therefore is ecological with no direct Ozone Depletion Potential and zero direct Global Warming Potential. Caloric refrigeration embraces four main cooling techniques, each one based on a different caloric effect. This paper is focused upon materials that display mechanocaloric properties, with a transition induced through the application of variable pressure (barocaloric cooling) or uniaxial stress (elastocaloric cooling). Materials that display solidstate caloric effects driven by applied pressure/stress could lead to more accessible and economic technological solutions. By means of a two-dimensional mathematical model an energy analysis is performed with the most performing elastocaloric and barocaloric materials to explore the potential of mechanocaloric cooling. Temperature span, cooling power and coefficient of performance have bene evaluated. Results demonstrate best mechanocaloric materials, like Cu68.13Zn15.74Al16.14 and (NH4)2MoO2F4, provide energy performances better than those of traditional vapour compression plants. Keywords:caloric cooling, mechanocaloric, elastocaloric, barocaloric, caloric effect, caloric materials ∆ = ∫ ( ) 1 0 ,(1)

show abstract

Section: Methodsmentioning

confidence: 99%

A comparison between different materials with mechanocaloric effect

Aprea¹,

Greco²,

Maiorino³

et al. 2018

IJHT

Self Cite

View full text Add to dashboard Cite

show abstract

“…This extreme ductility constitutes a strongpoint of the tool, and it allows for the possibility of experimentally validating the model with just one of the four caloric effect-based prototypes. To this purpose, the model was introduced in our previous investigations [16,67] and validated with a prototype of a magnetocaloric cooler developed at University of Salerno. The validation, carried out both at zero load and with refrigerant load, showed fairly good agreement with experimental data [16,67,69].…”

Section: Numerical Modelmentioning

confidence: 99%

“…In this paper, we introduce a numerical study conducted on an active barocaloric refrigerator operating with a vulcanizing rubber, which employed glycol-based nanofluids as auxiliary fluid. The tool employed for the investigation was a two-dimensional model of a parallel-plates active caloric regenerator, which was already validated experimentally in our previous investigations [16,67,68]. The analysis is focused mainly on the heat transfer performances of the regenerator.…”

Section: Introductionmentioning

confidence: 99%

Enhancing the Heat Transfer in an Active Barocaloric Cooling System Using Ethylene-Glycol Based Nanofluids as Secondary Medium

et al. 2019

Self Cite

View full text Add to dashboard Cite

Barocaloric cooling is classified as environmentally friendly because of the employment of solid-state materials as refrigerants. The reference and well-established processes are based on the active barocaloric regenerative refrigeration cycle, where the solid-state material acts both as refrigerant and regenerator; an auxiliary fluid (generally water of water/glycol mixtures) is used to transfer the heat fluxes with the final purpose of subtracting heat from the cold heat exchanger coupled with the cold cell. In this paper, we numerically investigate the effect on heat transfer of working with nanofluids as auxiliary fluids in an active barocaloric refrigerator operating with a vulcanizing rubber. The results reveal that, as a general trend, adding 10% of copper nanoparticles in the water/ethylene-glycol mixture carries to +30% as medium heat transfer enhancement.Energies 2019, 12, 2902 2 of 15 effects (ECE) [20][21][22], and mechanical fields provoke elastocaloric (eCE) [23] or barocaloric effects (BCE) [24], respectively, as consequences of stretching or of hydrostatic pressure application.Caloric cooling is classified as environmentally friendly because it employs solid-state materials as refrigerants that do not directly impact global warming since they do not disperse in the atmosphere, as confirmed by a certain number of investigations [25][26][27][28] that asserted the eco-friendliness of all the techniques belonging to magneto- [29,30], electro-[31,32], elasto-[33,34], and baro-caloric [35] cooling.The reference and well-established systems for caloric cooling are based on the active caloric regenerative refrigeration (ACR) cycle, a thermodynamic Brayton-based cycle in which the caloric solid-state material acts as both the refrigerant and the regenerator, thus recovering heat fluxes through the help of an auxiliary fluid that vehiculates them with the final purpose of subtracting heat from the cold heat exchanger (and therefore the cold environment) [36]. To improve the efficiency of a caloric cooler, the ACR system works with the optimal operative parameters (such as the geometry of the regenerator, the fluid velocity, and the frequency of the cycle) [37-39] but the bottleneck is employing materials due of high caloric effect in the temperature range toward the application is devoted to [40]. A very wide "chapter" is currently open in the research panorama regarding the efforts to realize suitable caloric effect materials. A huge number of studies have been conducted over the last decades, and several promising materials have been identified for each specific caloric technique [41][42][43].Magnetocaloric is the most mature solid-state cooling technique [44,45], as it was the first to be investigated; however, there are still inherent limitations and holdups in creating high-intensity magnetic fields by permanent magnet application [46,47]. More recently, electrocaloric and elastocaloric techniques have gained interest in the scientific community-certain objectives are being reached, and many prototypes...

show abstract

“…In this model both the fluid flow and heat transfer between the solid and the fluid have been taken in account. The fluid flows in the positive x direction during the isofield cooling process and in the opposite direction during isofield heating [14][15][16][17][18][19][20][21][22].…”

Section: Description Of the 2d Modelmentioning

confidence: 99%

Magnetic refrigeration: A comparison between MnAs and FeRh based alloys in the room temperature range

Aprea¹,

Greco²,

Maiorino³

et al. 2018

TI-IJES

Self Cite

View full text Add to dashboard Cite

This paper describes a two-dimensional (2D) multiphysics model of a parallel plate regenerator made of magnetocaloric material. The regenerator operates as a refrigerant for a magnetic refrigerator operating at room temperature on the strength of an Active Magnetic Regenerator (AMR) cycle. The model is able to simulate the thermofluidodynamic behavior of the magnetocaloric material and the magnetocaloric effect of the refrigerant. With this model direct (MnFeP0.45As0.55) and inverse (Fe49Rh51) magnetocaloric materials have been investigated. The tests were performed with fixed AMR cycle frequency (1.25 Hz), cold heat exchanger temperature (310 K), hot heat exchanger temperature (318 K), while secondary fluid flow rate was varied in the range 0.034÷0.057 kg/s. The secondary fluid used for simulations is liquid water. The results, generated for a magnetic induction which varies from 0 to 1.5 T, are presented in terms of temperature span, refrigeration power and coefficient of performance. Results clearly show that the best material from an efficiency's point of view is Fe49Rh51 which exhibits the highest values of ΔTspan, Qref and COP. Instead MnFeP0.45As0.55 shows, in this temperature range (centered around its Curie point), values of ΔTspan, Qref and COP too low for any kind of practical application.

show abstract

A comparison between experimental and 2D numerical results of a packed-bed active magnetic regenerator

Cited by 55 publications

References 31 publications

A comparison between different materials with mechanocaloric effect

A comparison between different materials with mechanocaloric effect

Enhancing the Heat Transfer in an Active Barocaloric Cooling System Using Ethylene-Glycol Based Nanofluids as Secondary Medium

Magnetic refrigeration: A comparison between MnAs and FeRh based alloys in the room temperature range

Contact Info

Product

Resources

About