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

Ciro Aprea,Adriana Greco,Claudia Masselli,Angelo Maiorino

doi:10.3390/en12152902

Abstract

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.

Highlights

The 21st century is characterized by a strong increase in energy demand
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 is used to transfer the heat fluxes with the final purpose of subtracting heat from the cold heat exchanger coupled with the cold cell
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

Summary

Introduction

The 21st century is characterized by a strong increase in energy demand. The World Bank. Since the auxiliary fluid is responsible for the heat vehiculation in the regenerator from one side to another, optimizing solutions should be proposed for enhancing the heat transfer between the solid-state refrigerant and the fluid itself. One of these is constituted by nanofluids. Nanofluids are classified as a new kind of heat transfer fluid; they are formed by common base fluids in which solid-state nanoparticles are dispersed due to high thermal conductivity. The use of nanofluids seems to be very promising in enhancing the thermal conductivity of a base fluid, but attention must be paid to the synthesis and the characterizations of them.

ABR Cycle

The Solid-State Barocaloric Refrigerant

Q about

Working Conditions of the Investigation

Discussion

Conclusions