Exhaust catalyst heating system - has containers contg. solids for high and low temp. reaction with gas, esp. hydrogen@

摘要

An exhaust catalyst heating system, esp. for use during engine cold starting, has at least two gastight containers (10') connected together by a line (8) fitted with a valve (9). The first container is filled with a high temp. solid, which reacts reversibly and exothermically at high temp. with a certain gaseous medium, and is in thermal contact with the support body of the catalyst (2a) or with an upstream heat exchanger. The second container (10') is filled with a low temp. solid, which reacts at low temp. with the gaseous medium, or, when the gaseous medium condenses at low temp. (esp. ambient temp.) filled only with the liq. phase of the gaseous medium and is in thermal contact with a region at much lower temp. than in the catalyst (2a) or the exhaust pipe (1) (esp. at ambient temp.) during operation. The low temp. solid is pref. a low temp. hydride and the high temp. solid is pref. a hydrogen-reactive high temp. hydride (pref. Tia nd opt. Mg hydrides) or a Ba cpd. (esp. BaO). ADVANTAGE - The system provides large amts. of heat rapidly without recourse to electrical energy.