Influence of Heat Exchanger Design on the Thermal Performance of a Domestic Wine Cooler Driven by a Magnetic Refrigeration System

PEIXER, GUILHERME F.; DUTRA, SERGIO L.; CALOMENO, RICARDO S.; SÁ, NATÁLIA M. DE; LANG, GUSTTAV B.; LOZANO, JAIME A.; BARBOSA JR, JADER R.

doi:10.1590/0001-3765202220200563

GUILHERME F. PEIXER

Universidade Federal de Santa Catarina, Departamento de Engenharia Mecânica, Laboratórios de Pesquisa em Refrigeração e Termofísica (POLO), Campus Trindade, Rua Roberto Sampaio Gonzaga, s/n, Trindade, 88040-900 Florianópolis, SC, Brazil

https://orcid.org/0000-0002-5238-4910

SERGIO L. DUTRA

Universidade Federal de Santa Catarina, Departamento de Engenharia Mecânica, Laboratórios de Pesquisa em Refrigeração e Termofísica (POLO), Campus Trindade, Rua Roberto Sampaio Gonzaga, s/n, Trindade, 88040-900 Florianópolis, SC, Brazil

https://orcid.org/0000-0002-1933-5797

RICARDO S. CALOMENO

Universidade Federal de Santa Catarina, Departamento de Engenharia Mecânica, Laboratórios de Pesquisa em Refrigeração e Termofísica (POLO), Campus Trindade, Rua Roberto Sampaio Gonzaga, s/n, Trindade, 88040-900 Florianópolis, SC, Brazil

https://orcid.org/0000-0001-7916-2747

NATÁLIA M. DE SÁ

Universidade Federal de Santa Catarina, Departamento de Engenharia Mecânica, Laboratórios de Pesquisa em Refrigeração e Termofísica (POLO), Campus Trindade, Rua Roberto Sampaio Gonzaga, s/n, Trindade, 88040-900 Florianópolis, SC, Brazil

https://orcid.org/0000-0002-5584-6279

GUSTTAV B. LANG

Universidade Federal de Santa Catarina, Departamento de Engenharia Mecânica, Laboratórios de Pesquisa em Refrigeração e Termofísica (POLO), Campus Trindade, Rua Roberto Sampaio Gonzaga, s/n, Trindade, 88040-900 Florianópolis, SC, Brazil

https://orcid.org/0000-0002-9033-341X

JAIME A. LOZANO

Universidade Federal de Santa Catarina, Departamento de Engenharia Mecânica, Laboratórios de Pesquisa em Refrigeração e Termofísica (POLO), Campus Trindade, Rua Roberto Sampaio Gonzaga, s/n, Trindade, 88040-900 Florianópolis, SC, Brazil

https://orcid.org/0000-0003-2682-9952

JADER R. BARBOSA JR

Universidade Federal de Santa Catarina, Departamento de Engenharia Mecânica, Laboratórios de Pesquisa em Refrigeração e Termofísica (POLO), Campus Trindade, Rua Roberto Sampaio Gonzaga, s/n, Trindade, 88040-900 Florianópolis, SC, Brazil

https://orcid.org/0000-0002-8753-6670

Correspondence to: Jader R. Barbosa Jr E-mail: jrb@polo.ufsc.br

AUTHOR CONTRIBUTIONS

JAL and JRB obtained funding for the research. GFP, SLD, GBL, RSC, JAL and JRB developed the theoretical formalism. GBL and GFP implemented the model and performed the simulations. SLD, NMS, GFP and JAL conceived, planned and executed the experiments. GFP, SLD, NMS, RSC, GBL, JAL and JRB analyzed the data. GFP, JAL and JRB wrote the manuscript with input from all authors.

Parameter	Symbol	Value
Heat exchanger length [mm]	$L$	110
Heat exchanger height [mm]	$H$	152
Longitudinal tube pitch [mm]	$X_{l}$	21.5
Transversal tube pitch [mm]	$X_{t}$	25.4
Inner tube diameter [mm]	$D_{i}$	6.5
Outer tube diameter [mm]	$D_{o}$	7.5

Variable	Uncertainty
${\bar{T}}_{a m b}$	0.12°C
${\bar{T}}_{c a b}$	0.1°C
$Δ T_{s p a n}$	0.16°C
${(U A)}_{c a b}$	0.08 W K $^{- 1}$
${\dot{Q}}_{c a b}$	3 W

Parameter	Admissible values
Ambient temperature ( $T_{a m b}$ ), °C	25 $\pm$ 1
Relative humidity, $%$	55 $\pm$ 15
Cold liquid mass flow rate ( ${\dot{m}}_{c, l}$ ), kg h $^{- 1}$	150 $\pm$ 1

Parameter	Value
Number of regenerator beds	8
Regenerator bed length	70 mm
Regenerator bed height	19 mm
Regenerator bed width	30 mm
Particle diameter	0.435 mm
Mass flow rate per regenerator (Min/Max)	0 kg h $^{- 1}$ / 75 kg h $^{- 1}$
Operating frequency	1 Hz
Hot reservoir temperature	298.15 K (25°C)
Cold reservoir temperature	278.15 K (5°C)
Magnetic field (Min/Max)	0 T / 1.15 T
Gd Curie Temperature	290 K (17°C)
Magnetic field fraction	35%
Fluid flow fraction	25%

Roman
$A$	area, m $^{2}$
$B$	magnetic Field, T
$\dot{C}$	thermal capacity rate, W K $^{- 1}$
$C^{*}$	thermal capacity rate ratio
$c_{p}$	isobaric specific heat capacity, J kg $^{- 1}$ K $^{- 1}$
$D$	diameter, m
$D C$	duty cycle
$F$	fraction
$f$	friction factor
$f_{r}$	frequency, s $^{- 1}$
$G$	mass flux, kg m $^{- 2}$ s $^{- 1}$
$H$	height, m
$h$	convective heat transfer coefficient, W m $^{- 2}$ K $^{- 1}$
$j$	colburn factor
$k$	thermal conductivity, W m $^{- 1}$ K $^{- 1}$
$L$	length, m
$m_{s}$	solid mass, kg
$\dot{m}$	mass flow rate, kg s $^{- 1}$
$N$	number
$N T U$	number of transfer units
$P r$	Prandtl number
$P$	pressure, Pa
${\dot{Q}}_{c}$	cooling capacity, W
${\dot{Q}}_{c a b}$	heat loss through the cabinet wall, W
${\dot{Q}}_{h}$	heat rejection rate, W
$s$	specific entropy, J kg $^{- 1}$ K $^{- 1}$
$T$	temperature, K, °C
$U A$	overall thermal conductance, W K $^{- 1}$
$\dot{V}$	volumetric flow rate, m $^{3}$ s $^{- 1}$
$W$	width, m
$\dot{W}$	power consumption, W
$X_{f}$	fin pitch, m
$X_{l}$	longitudinal tube pitch, m
$X_{t}$	transversal tube pitch, m

Greek
$Δ$	variation
$ϵ$	effectiveness
$η$	efficiency
$ρ$	density, kg m $^{- 3}$
$σ$	fin density, m $^{- 1}$
$τ$	period, s

Subscripts
a	air
amb	ambient
avg	average
bot	bottom
B	magnetic Field
c	cold
cab	cabinet
CHEx	Cold heat exchanger
ext	external
fan	fan
fin	fin surface
F	fluid flow
h	hot
HHEx	hot heat exchanger
hyd	hydraulic
i	inner
in	inlet
int	internal
l	liquid
mag	magnetization
max	maximum
min	minimum
net	net
nom	nominal
o	outer
out	outlet
pump	pumping
r	row
reg	regenerator
span	system temperature span
t	tube
top	top
valv	valves

Superscripts
exp	experimental
num	numerical
$\bar{}$	average

Abbreviations
AMR	active magnetic regenerator
HEx	heat exchanger
MCE	magnetocaloric effect

HEx	Number of rows, $N_{r}$	Fin density, $σ$
1	1	300
2	1	400
3	1	500
4	2	300
5	2	400
6	2	500

Brasil

Brasil

Influence of Heat Exchanger Design on the Thermal Performance of a Domestic Wine Cooler Driven by a Magnetic Refrigeration System

Abstract