Is Barocaloric an Eco-Friendly Technology? A TEWI Comparison with Vapor Compression under Different Operation Modes

Abstract

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%.

Hybrid ionic plastic crystals in the race for enhanced low-pressure barocaloric materials

“…[6][7][8] For a solid-state compound to be considered a good barocaloric, it should fulfill certain characteristics, specially: near-room-temperature phase transition, associated extremely large entropy changes, and easy-achievable operating pressures to avoid irreversible thermal losses. [9][10][11][12] In a first approximation, the ideal barocaloric material for commercial refrigeration would display colossal thermal changes (barocaloric effects of ΔS > 100 J K -1 kg -1 ) near ambient temperature (from ~315 K down to ~273 K, or even lower in the case of freezing devices), and under the application of pressures well-below 1000 bar. 1 Thus, it is primordial to find materials with colossal and reversible isothermal entropy changes, ΔSrev, (and adiabatic temperature changes, ΔTrev), large barocaloric coefficient (dTt/dp) and strength (ΔSrev/Δp) 13 (sensitivity to pressure) and appropiate operating temperature (Top) 14 , which is the thermal region where the barocaloric effect can be reversibly induced.…”

A colossal barocaloric effect induced by the creation of a high-pressure phase

“…Solid-state refrigeration technology based on caloric effects has recently attracted extensive attention given that the employed solid working materials are emission-free, which provides a promising alternative solution to the current vapor-compression refrigeration. [1][2][3] Caloric effects are usually categorized as magnetocaloric effects, 4,5 electrocaloric effects, 6,7 elastocaloric effects, 8,9 and barocaloric effects (BCEs) [10][11][12][13] in terms of driving fields, i.e., magnetic field, electric field, uniaxial stress field and hydrostatic pressure. The discovery of colossal BCEs in plastic crystals has paved an emerging routine to solid-state refrigeration due to the larger entropy change, smaller driven pressure, and lower cost of these plastic crystals.…”