System Simulation of an Elastocaloric Heating and Cooling Device Based on SMA

Abstract

Elastocaloric (EC) cooling uses solid-state NiTi-based shape memory alloy (SMA) as a non-volatile cooling medium and enables a novel environment-friendly cooling technology. Due to the high specific latent heats activated by mechanical loading/unloading, substantial temperature changes are generated in the material. Accompanied by a small required work input, a high coefficient of performance is achievable. Recently, a fully functional and illustrative continuous operating elastocaloric air cooling system based on SMA was developed and realized. To assist the design process of an optimized device with given performance and efficiency requirements, a fully coupled thermo-mechanical system-level model of the multi-wire cooling unit was developed and implemented in MATLAB. The resulting compact simulation tool is qualified for massively parallel computation, which allows fast and comprehensive parameter studies. In this work, the influence of different SMA diameters, rotation frequencies, and airflow rates is investigated. The results are analyzed to find the suited parameter for high efficiency (COP) and temperature span.

Self‐Closing and Self‐Healing Multi‐Material Suction Cups for Energy‐Efficient Vacuum Grippers

“…Motzki et al developed a shape memory alloy (SMA) driven SC that achieves a 20 Newton holding force with just 4.5 V. [ 15 ] Welsch et al created a bistable SC using SMA wires, combined with a bistable spring and integrated condition monitoring through the self‐sensing effect of SMA. [ 16 ] However, the slow recovery of SMA during cooling affects the time efficiency of SMA‐actuated SCs, limiting their applications. [ 17 ] Lyu et al proposed a flexible vacuum gripper based on the reversible flat‐to‐conical deformation of azimuthally aligned liquid‐crystal elastomer films, which achieves highly integrated performance, exerting a force that is 100 times its own weight.…”

Modeling of an Elastocaloric Cooling System for Determining Efficiency

“…Furthermore, the system's efficiency can be quantified and compared to the theoretical limit given by the properties of the elastocaloric material, enabling the quantification of further optimization potential. In the literature, different approaches of elastocaloric cooling systems have been studied regarding their efficiency with simulations [20][21][22][23]. In this publication, we present a simulation model of the AEH that was validated with experimental data.…”

An analytical model for a multilayer elastocaloric cooling regenerator

“…Based on the iterative calculation in the modeling, the specific cooling power and temperature span can be obtained through the design parameters, including material properties, operating conditions, number of layers, and phase transition temperature at each layer. [22][23][24][25] On the other hand, the potential of elastocaloric regenerator was investigated via modeling various structures, such as tubular, 26 packed-cylinder, 27 wire, 28 and micro-channel. 29 Tu sek et al 30 developed a one-dimensional (1D) steady state numerical model based on the tension NiTi-plate regenerator and produced a specific cooling power (SCP) of up to 7 kW/kg and COP of 5 at the DT span of 30 K. Welsch et al 28 established a thermo-mechanical coupling model of a multi-wire rotary system with the variation of fluid flow rate and rotation frequency.…”

“…[22][23][24][25] On the other hand, the potential of elastocaloric regenerator was investigated via modeling various structures, such as tubular, 26 packed-cylinder, 27 wire, 28 and micro-channel. 29 Tu sek et al 30 developed a one-dimensional (1D) steady state numerical model based on the tension NiTi-plate regenerator and produced a specific cooling power (SCP) of up to 7 kW/kg and COP of 5 at the DT span of 30 K. Welsch et al 28 established a thermo-mechanical coupling model of a multi-wire rotary system with the variation of fluid flow rate and rotation frequency. Kalizan et al 29 developed a 1D micro-channel elastocaloric system model and achieved a COP of above 10 and heat flux density of 1 W cm À3 .…”