Experimental study on heat transfer characteristics of spray cooling system with plate-fin heat exchanger

ABSTRACT

An intermittent spray cooling system is applied to fuel cell vehicle heat dissipation using a plate-fin heat exchanger. The effects of various system parameters on cooling performances are evaluated. Experimental results indicate that the cooling performance can be increased by 20% to 80% at various operating conditions and fixed spray area percentage of 45%. An empirical correlation is constructed to characterize heat transfer enhancement percentage. For the 124 data points examined, 92.73% of the data are within 20% of the error range, and 81.8% are within 15% of the error range. The average absolute deviation is 9.30%.

KEYWORDS:

• Fuel cell vehicle
• intermittent spray cooling
• heat transfer enhancement
• empirical correlation

Nomenclature

$c_{\mathrm{p}}$	=	Specific heat capacity ($\mathrm{J}/\left(\mathrm{k}\mathrm{g}\cdot \right)$)
$D_h$	=	Hydraulic diameter ($\mathrm{m}\mathrm{m}$)
$\dot{m}$	=	Mass flow rate (kg$/\mathrm{s}$)
$P$	=	Pressure ($\mathrm{P}\mathrm{a}$)
$Q$	=	Heat load ($\mathrm{W}$)
$R_{\mathrm{a}\mathrm{r}\mathrm{e}\mathrm{a}}$	=	Spray surface area ratio
$R_{\mathrm{s}}$	=	Spray ratio
$Re$	=	Reynolds number
$T$	=	Temperature ($NIL$)
$V$	=	Velocity ($\mathrm{m}/\mathrm{s}$)
$t$	=	Time ($\mathrm{s}$)
Greek letters	=
$\rho$	=	Density (kg$/{\mathrm{m}}^3$)
$\mu$	=	Viscosity ($\mathrm{P}\mathrm{a}\cdot \mathrm{s}$)
$\eta$	=	Heat transfer enhancement percentage
∅	=	Humidity (%)
Subscripts	=
$\mathrm{e}\mathrm{x}\mathrm{p}$	=	Experiment
$\mathrm{i}$	=	Inlet
$\mathrm{o}$	=	Outlet
$\mathrm{p}\mathrm{r}\mathrm{e}$	=	Predicted
$\mathrm{t}\mathrm{o}\mathrm{t}$	=	Total
$\mathrm{w}$	=	Water

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This paper is supported by the Young Teacher Development Fund (AQ08998) from School of Energy and Power Engineering, Nanjing University of Science and Technology.