scholarly journals The environmental impact of solid-state materials working in an active caloric refrigerator compared to a vapor compression cooler

2018 ◽  
Vol 36 (4) ◽  
pp. 1155-1162 ◽  
Author(s):  
Ciro Aprea ◽  
Adriana Greco ◽  
Angelo Maiorino ◽  
Claudia Masselli
2021 ◽  
Vol 65 (1) ◽  
pp. 58-66
Author(s):  
Adriana Greco ◽  
Adriana R. Farina ◽  
Claudia Masselli

Magnetic refrigeration is a promising and ecologic technology, alternative to the conventional vapor-compression refrigeration by the employment of solid-state materials as refrigerants instead of the fluid-state ones, own of vapour compression refrigeration. This emerging technology bases its operation on the MagnetoCaloric Effect (MCE), which is a physical phenomenon, related to solid-state materials with magnetic properties. For materials displaying simple magnetic ordering (i.e. paramagnetic to ferromagnetic phase transformations) a rapid increase in magnetic field causes a temperature rise in the material; likewise, a rapid reduction in the field causes cooling. This variation in temperature is called adiabatic temperature change. In 1982 the Active Magnetic Regenerative refrigeration cycle, well known as AMR cycle was introduced. The innovative idea considers a magnetic Brayton cycle but the main innovation consists of introducing the AMR regenerator concept, i.e. the employment of the magnetic material itself both as refrigerant and as regenerator. A secondary fluid is used to transfer heat from the cold to the hot end of the regenerator. Substantially every section of the regenerator experiments its own AMR cycle, according to the proper working temperature. Through an AMR one can appreciate a larger temperature span among the ends of the regenerator.


Climate ◽  
2019 ◽  
Vol 7 (9) ◽  
pp. 115 ◽  
Author(s):  
Aprea ◽  
Greco ◽  
Maiorino ◽  
Masselli

Barocaloric is a solid-state not-in-kind technology, for cooling and heat pumping, rising as an alternative to the vapor compression systems. The former is based on solid-state refrigerants and the latter on fluid ones. The reference thermodynamical cycle is called active barocaloric regenerative refrigeration (or heat pumping cycle). The main advantage of this technology is to not employ greenhouse gases, which can be toxic or damaging for the environment and that can contribute to increasing global warming. In this paper, the environmental impact of barocaloric technology was evaluated through a Total Equivalent Warming Impact (TEWI) analysis carried out with the help of a numerical 2D model solved through a finite element method. Specifically, we propose a wide investigation on the environmental impact of barocaloric technology in terms of TEWI index, also making a comparison with a vapor compression plant. The analysis focuses on both the cooling and heat pump operation modes, under different working conditions and auxiliary fluids. The results revealed that a barocaloric system based on ABR cycle could provide a reduction of the environmental impact with respect to a vapor compression system. The addition of nanofluids contributes in reducing the environmental impact up to –62%.


2021 ◽  
Author(s):  
Corey R. Martin ◽  
Kyoung Chul Park ◽  
Ryan E. Corkill ◽  
Preecha Kittikhunnatham ◽  
Gabrielle A. Leith ◽  
...  

In this paper, spiropyran-containing metal- and covalent-organic frameworks (MOFs and COFs, respectively) are probed as platforms for fostering photochromic behavior in solid-state materials while simultaneously promoting directional energy transfer (ET)....


1987 ◽  
Vol 97 ◽  
Author(s):  
Steven A. Sunshine ◽  
Doris Kang ◽  
James A. Ibers

ABSTRACTThe use of A2 Q/Q melts (A - alkali metal, Q - S or Se) for the synthesis of new one-dimensional solid-state materials is found to be of general utility and is illustrated here for the synthesis of K4 Ti3 SI4. Reaction of Ti metal with a K2 S/S melt at 375°C for 50 h affords K4 Ti3 SI4. The structure possesses one-dimensional chains of seven and eightcoordinate Ti atoms with each chain isolated from all others by surrounding K atoms. There are six S-S pairs (dave - 2.069(3) Å) so that the compound is one of TiIV and may be described as K4 [Ti3 (S)2 (S2)6]. Electrical conductivity measurements indicate that this material is a semiconductor.


2021 ◽  
Author(s):  
Jarad Mason ◽  
Jinyoung Seo ◽  
Ryan McGillicuddy ◽  
Adam Slavney ◽  
Selena Zhang ◽  
...  

Abstract Nearly 4,400 TWh of electricity—20% of the total consumed in the world—is used each year by refrigerators, air conditioners, and heat pumps for cooling. In addition to the 2.3 Gt of carbon dioxide emitted during the generation of this electricity, the vapor-compression-based devices that provided the bulk of this cooling emitted fluorocarbon refrigerants with a global warming potential equivalent to 1.5 Gt of carbon dioxide into the atmosphere. With population and economic growth expected to dramatically increase over the next several decades, the development of alternative cooling technologies with improved efficiency and reduced emissions will be critical to meeting global cooling needs in a more sustainable fashion. Barocaloric materials, which undergo thermal changes in response to applied hydrostatic pressure, offer the potential for solid-state cooling with high energy efficiency and zero direct emissions, as well as faster start-up times, quieter operation, greater amenability to miniaturization, and better recyclability than conventional vapor-compression systems. Efficient barocaloric cooling requires materials that undergo reversible phase transitions with large entropy changes, high sensitivity to hydrostatic pressure, and minimal hysteresis, the combination of which has been challenging to achieve in existing barocaloric materials. Here, we report a new mechanism for achieving colossal barocaloric effects near ambient temperature that exploits the large volume and conformational entropy changes of hydrocarbon chain-melting transitions within two-dimensional metal–halide perovskites. Significantly, we show how the confined nature of these order–disorder phase transitions and the synthetic tunability of layered perovskites can be leveraged to reduce phase transition hysteresis through careful control over the inorganic–organic interface. The combination of ultralow hysteresis (< 1.5 K) and high barocaloric coefficients (> 20 K/kbar) leads to large reversible isothermal entropy changes (> 200 J/kg•K) at record-low pressures (< 300 bar). We anticipate that these results will help facilitate the development of barocaloric cooling technologies and further inspire new materials and mechanisms for efficient solid-state cooling.


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