Emissions treatment in genset engines through air injection into the exhaust system of a genset

Abstract

An exhaust system that can improve emissions treatment by reducing certain emissions species. The exhaust system draws air into the exhaust system from an air source, when exhaust pressure decreases to a threshold so that air can enter the exhaust system. The exhaust system is in a genset engine. The air source is a pressurized air source, such as an existing fan of the genset engine. A portion of the air generated by the air source is pulled off so that it flows directly toward the exhaust system, using a one-way valve and conduit that fluidly connects the air source to the exhaust system.

1 . A genset comprising:
 an exhaust system including an exhaust manifold configured to fluidly connect to a genset engine and receivable of exhaust flow from the genset engine, the exhaust manifold is fluidly connected with a catalytic device configured to provide aftertreatment of the exhaust flow;   a pressurized source of air; and   a one-way valve connected to the pressurized source of air and configured to fluidly connect the pressurized source of air to the exhaust manifold,   wherein the one-way valve is configured to deliver an amount of air from the pressurized source of air to the exhaust manifold, when an exhaust pressure in the exhaust system decreases.   
     
     
         2 . The genset of  claim 1 , wherein the pressurized source of air is a cooling fan. 
     
     
         3 . The genset of  claim 1 , wherein the pressurized source of air is an existing fan configured to provide a main flow to other genset components, and provide a secondary air flow to the exhaust system. 
     
     
         4 . The genset of  claim 1 , wherein the one-way valve is a reed valve configured to open when the exhaust pressure decreases to a threshold and configured to be closed when the exhaust pressure has not reached the threshold. 
     
     
         5 . The genset of  claim 1 , wherein the one-way valve is configured to deliver a pulse of air to the exhaust manifold each time the exhaust pressure in the exhaust system is lower than the pressurized source of air. 
     
     
         6 . The genset of  claim 1 , further comprising a conduit that fluidly connects the one-way valve to the exhaust manifold. 
     
     
         7 . A method of reducing emissions in a genset engine comprising:
 receiving exhaust flow from a genset engine into an exhaust manifold;   decreasing exhaust pressure in the exhaust manifold;   injecting air from a pressurized source of air into the exhaust manifold when the exhaust pressure decreases; and   mixing the air with the exhaust flow and treating the exhaust flow with an aftertreatment device to thereby reduce engine emissions.   
     
     
         8 . The method of  claim 7 , wherein the step of injecting air comprises delivering a pulse of air for each instance the exhaust pressure decreases to a certain threshold. 
     
     
         9 . The method of  claim 8 , wherein the pulse of air being delivered through a one-way valve configured to open when the exhaust pressure decreases to a threshold and configured to be closed when the exhaust pressure has not reached the threshold.