Effect of inactive section on cooling performance of compressive elastocaloric refrigeration prototype

Zhang，Jiongjiong1,2; Zhu，Yuxiang2; Cheng，Siyuan2,3; Yao，Shuhuai2; Sun，Qingping2,4

2023-12-01

10.1016/j.apenergy.2023.121839

Applied Energy   Impact Factor & Quartile

0306-2619

1872-9118

Elastocaloric (eC) cooling using shape memory alloy (SMA) with zero direct carbon emission is a promising alternative of traditional vapor-compression technology. Compressive eC refrigeration prototype (ERP) performs high fatigue life but suffers from the limited cooling performance. Many studies focus on enhancing the heat transfer property of compressive eC regenerators to improve the specific cooling power (SCP). However, reducing the SCP loss is also essential for developing high-cooling-performance compressive ERPs but has not been given sufficient attention. In this study, we revealed that the force holder widely used in compressive ERPs works as an inactive section that dramatically reduce the SCP produced by the NiTi SMA active section. Numerical heat transfer simulations and experiments were conducted to study the impact of the inactive section on the SCP at varied operation parameters. Nondimensionalized governing equations of the numerical model revealed that the volume ratio (Vol) of the fluid channel of the inactive section to that of the active section is the determinant geometric parameter for the SCP decrease. Numerical results show that, larger operation frequency f, smaller dimensionless fluid velocity V* and system temperature span (∆T) lead to more pronounced decreases in SCP (ratio of the SCP to ideal SCP at Vol = 0) as the Vol increases. It also indicates that the Vol should be minimized to better < 0.08 for achieving excellent SCP > 0.95. Experiments validate that the regenerator with a reduced Vol = 0.08 exhibits a notable increase of 30.8% and 66.7% in zero-∆T SCP and no-load ∆T respectively, in comparison to the regenerator with Vol = 0.5. Therefore, minimizing the Vol of the inactive section via reducing the length and diameter of the fluid channel inside the force holder is necessary and highly recommended for developing high-performance compressive ERPs.

Cooling performance enhancement Cyclic compression Elastocaloric Inactive section NiTi tube

SCI

English

First ; Corresponding

Hong Kong Research Grant Council[16206119] ; Project of Hetao Shenzhen-Hong Kong Science and Technology Innovation Cooperation Zone[HZQB-KCZYB-2020083] ; Science, Technology and Innovation Commission of Shenzhen Municipality of China[SGDX2019081623360564]

Energy & Fuels ; Engineering

Energy & Fuels ; Engineering, Chemical

WOS:001082090500001

ELSEVIER SCI LTD

ENGINEERING

2-s2.0-85169615662

Scopus

1.Department of Materials Science and Engineering,Southern University of Science and Technology,Shenzhen,Guangdong,China
2.Department of Mechanical and Aerospace Engineering,The Hong Kong University of Science and Technology,Clear Water Bay,Hong Kong
3.School of Mechanical Engineering,Hebei University of Science and Technology,Shijiazhuang,Hebei,China
4.HKUST Shenzhen-Hong Kong Collaborative Innovation Research Institute,Shenzhen,Guangdong,China

Zhang，Jiongjiong,Zhu，Yuxiang,Cheng，Siyuan,et al. Effect of inactive section on cooling performance of compressive elastocaloric refrigeration prototype[J]. Applied Energy,2023,351.

Zhang，Jiongjiong,Zhu，Yuxiang,Cheng，Siyuan,Yao，Shuhuai,&Sun，Qingping.(2023).Effect of inactive section on cooling performance of compressive elastocaloric refrigeration prototype.Applied Energy,351.

Zhang，Jiongjiong,et al."Effect of inactive section on cooling performance of compressive elastocaloric refrigeration prototype".Applied Energy 351(2023).