EnginSoft - CAE Conference Abstracts

EnginSoft International Conference 2011
CAE Technologies for Industry

Fluid Refrigerant Leak in a Cabin Compartment: Risk Assessment by CFD Approach

Mattiello Fabrizio - Centro Ricerche Fiat (Italy)

Abstract

In the framework of the Greenhouse gas emissions reduction initiatives the European Union (EU) requires that the air-conditioned vehicles sold in EU countries use refrigerants with Global Warming Potential (GWP) less than 150 starting from January 1st, 2011 for new vehicles type and in all vehicles by 2017 (regulation 2006/40/EC).
The air conditioning system of passenger cars, trucks and the vehicles manufactured uses, as refrigerant, the hydro fluorocarbon R-134a that has no effect on the atmospheric ozone layer but that has a GWP of 1430.
The Honeywell-DuPont fluid refrigerant named HFO-1234yf is, at the moment, the first option to replace the R-134a.
Critical open issues of this fluid are:
• It is flammable (R12 classified), even if its flammability is low (ASHRAE A2L)
• when burning, or a contact with hot surfaces, it produces toxic gases (HF)
• high cost

The present work has been focused to evaluate the risk of burning associated to the new refrigerant fluid leak in the cabin due to an evaporator fault in case of a vehicle crash and in case of exchanger corrosion.
A 3D model of a B-segment passenger car cabin and HVAC module and ducts has been analyzed. By means of CFD approach the refrigerant concentration has been identified for different working conditions.