Browse Prior Art Database

Arrangement for recirculation of exhaust gases of an internal combustion engine

IP.com Disclosure Number: IPCOM000184104D
Publication Date: 2009-Jun-11
Document File: 1 page(s) / 56K

Publishing Venue

The IP.com Prior Art Database

Abstract

The invention relates to a combustion engine having an exhaust gas recirculation (EGR) line with an EGR cooler. The object of the invention is to avoid corrosion in the EGR return line and in the internal combustion engine when condensate is formed comprising corrosive acids. According to the invention, urea solution is supplied to the condensate in order to neutralize the corrosive acids in the condensate

This text was extracted from a Microsoft Word document.
This is the abbreviated version, containing approximately 52% of the total text.

Arrangement for recirculation of exhaust gases of an internal combustion engine

By the technique called EGR (Exhaust Gas Recirculation), it is known to recirculate a part of the exhaust gases of an internal combustion engine in an EGR return line back to the cylinders of the engine. The recirculation of the exhaust gases results in a lower combustion temperature and lower emissions of nitrogen oxides NOX. In order to increase engine performance and reduce emissions of nitrogen oxides, the recirculating exhaust gases are cooled in at least one EGR-cooler in the EGR return line to a low temperature. However, the exhaust gases contain a relatively large amount of water vapour. If the exhaust gases are cooled to the condensing temperature of the water vapour, liquid water is formed in the EGR-cooler and in the downstream part of the EGR-return line. Fuel for internal combustion engines such as diesel oil and petrol contains sulphur. The existence of the sulphur in the fuel results in the formation of sulphur dioxide in the exhaust gases. When the sulphur dioxides come in contact with liquid water in the EGR return line, sulphuric acid is formed which is a very corrosive substance. Furthermore, when the nitrogen oxides in the exhaust gases come in contact with liquid water in the EGR return line, nitric acid is formed which is also a very corrosive substance. Consequently, if the recirculating exhaust gases are cooled to a l...