Low pressure EGR system for diesel engines
First Claim
Patent Images
1. An EGR system for a vehicle equipped with a diesel engine having an intake manifold and an exhaust manifold comprising:
- a turbocharger having a compressor for supplying combustion air to said intake manifold and a turbine operatively connected to said compressor for receiving exhaust gases from said exhaust manifold to operate said compressor;
an exhaust particulate filter downstream of and in fluid communication with the outlet of said turbine for removing particulate matter from the exhaust gases;
an EGR particulate filter positioned upstream of said exhaust particulate filter and downstream of said exhaust manifold;
an intake air filter upstream of the compressor for supplying filtered combustion air to said compressor;
a low pressure EGR line extending from an inlet downstream of said turbine to an outlet upstream of the compressor and downstream of the air filter;
said inlet of said EGR line formed as a pick-up tube containing said EGR particulate filter whereby backpressure developed on the exhaust gases by the exhaust particulate filter in combination with vacuum developed at said EGR line outlet by filtered combustion airflow from the air filter induces a slip stream of the exhaust gases to travel through said EGR line from its inlet to its outlet.
1 Assignment
0 Petitions
Accused Products
Abstract
A low pressure EGR system suitable for use as a passive retrofit system is disclosed for moving vehicles equipped with a diesel engine. The EGR loop inlet is positioned upstream of the exhaust particulate filter and downstream of the turbine to utilize backpressure created by the exhaust particulate filter to insure EGR flow in the loop. A catalyzed soot filter in communication with the EGR pickup insures cleansed EGR gases at the EGR return downstream of the air filter and upstream of the compressor. A corrugated EGR line provides cooling of the EGR gases.
-
Citations
17 Claims
-
1. An EGR system for a vehicle equipped with a diesel engine having an intake manifold and an exhaust manifold comprising:
-
a turbocharger having a compressor for supplying combustion air to said intake manifold and a turbine operatively connected to said compressor for receiving exhaust gases from said exhaust manifold to operate said compressor;
an exhaust particulate filter downstream of and in fluid communication with the outlet of said turbine for removing particulate matter from the exhaust gases;
an EGR particulate filter positioned upstream of said exhaust particulate filter and downstream of said exhaust manifold;
an intake air filter upstream of the compressor for supplying filtered combustion air to said compressor;
a low pressure EGR line extending from an inlet downstream of said turbine to an outlet upstream of the compressor and downstream of the air filter;
said inlet of said EGR line formed as a pick-up tube containing said EGR particulate filter whereby backpressure developed on the exhaust gases by the exhaust particulate filter in combination with vacuum developed at said EGR line outlet by filtered combustion airflow from the air filter induces a slip stream of the exhaust gases to travel through said EGR line from its inlet to its outlet. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
-
-
11. An EGR system for a vehicle equipped with a diesel engine having an intake manifold and an exhaust manifold comprising:
-
a turbocharger having a compressor for supplying combustion air to the intake manifold and a turbine operatively connected to the compressor for receiving exhaust gases from the exhaust manifold to operate the compressor;
an exhaust particulate filter downstream of and in fluid communication with the outlet of the turbine for removing particulate matter from the exhaust gases;
an intake air filter upstream of the compressor for supplying filtered combustion air to the compressor;
a low pressure EGR line extending from an inlet downstream of the turbine to an outlet upstream of the compressor and downstream of the air filter;
an inlet of the EGR line formed as a pick-up tube in fluid communication with an EGR particulate filter positioned upstream of the exhaust particulate filter whereby backpressure developed on the exhaust gases by the exhaust particulate filter in combination with vacuum developed at the EGR line outlet by filtered combustion airflow from the air filter induces a slip stream of the exhaust gases to travel through the EGR line from its inlet to its outlet;
an intercooler downstream of the compressor for cooling compressed combustion air and re-circulated exhaust gases to temperatures equal to or below the dew point of at least one of the combustion air and re-circulated exhaust gases, the intercooler having a reservoir for collecting condensation and a valve for removing collected condensation from the reservoir whereby injection of liquid in the form of water, nitric and sulfuric acids formed by reaction of condensed water with the exhaust gases into the combustion chamber of the engine is avoided; and
,a liquid sensor in the reservoir and an electronically actuated valve operable when the reservoir is under positive pressure and in response to set liquid sensor readings to drain the reservoir.
-
-
12. An EGR system for a vehicle equipped with a diesel engine having an intake manifold and an exhaust manifold comprising:
-
a turbocharger having a compressor for supplying combustion air to the intake manifold and a turbine operatively connected to the compressor for receiving exhaust gases from the exhaust manifold to operate the compressor;
an exhaust particulate filter downstream of and in fluid communication with the outlet of the turbine for removing particulate matter from the exhaust gases;
an intake air filter upstream of the compressor for supplying filtered combustion air to the compressor;
a low pressure EGR line extending from an inlet downstream of the turbine to an outlet upstream of the compressor and downstream of the air filter;
an inlet of the EGR line formed as a pick-up tube in fluid communication with an EGR particulate filter positioned upstream of the exhaust particulate filter whereby backpressure developed on the exhaust gases by the exhaust particulate filter in combination with vacuum developed at the EGR line outlet by filtered combustion airflow from the air filter induces a slip stream of the exhaust gases to travel through the EGR line from its inlet to its outlet;
said EGR particulate filter being a gas pervious wall flow filter with the walls thereof coated with a catalyst over which the exhaust gases entering the EGR line pass whereby soluble organic fractions and insoluble fractions of particulate matter drawn into the EGR line are effectively removed from the exhaust gases;
an intercooler downstream of the compressor for cooling compressed combustion air and re-circulated exhaust gases to temperatures equal to or below the dew point of at least one of the combustion air and re-circulated exhaust gases, the intercooler having a reservoir for collecting condensation and a valve for removing collected condensation from the reservoir whereby injection of liquid in the form of water, nitric and sulfuric acids formed by reaction of condensed water with the exhaust gases into the combustion chamber of the engine is avoided; and
,a liquid sensor in the reservoir and an electronically actuated valve operable when the reservoir is under positive pressure and in response to set liquid sensor readings to drain the reservoir.
-
-
13. An EGR system for a vehicle equipped with a diesel engine having an intake manifold and an exhaust manifold comprising:
-
a turbocharger having a compressor for supplying combustion air to said intake manifold and a turbine operatively connected to said compressor for receiving exhaust gases from said exhaust manifold to operate said compressor;
an exhaust particulate filter downstream of and in fluid communication with said outlet of said turbine for removing particulate matter from said exhaust gases produced by said engine;
an intake air filter upstream of said compressor for supplying filtered combustion air to said compressor;
a low pressure EGR line extending from an inlet downstream of said turbine to an outlet upstream of said compressor and downstream of said air filter; and
an air-to-air intercooler downstream of the compressor for cooling compressed combustion air and re-circulated exhaust gases to temperatures equal to or below the dew point of at least one of the combustion air and re-circulated exhaust gases, said intercooler having an inlet, an outlet and a reservoir for collecting condensation removed from said inlet and outlet with a valve for removing collected condensed water from the reservoir whereby injection of liquid in the form of water, nitric and sulfuric acids formed by reaction of condensed water with the exhaust gases into the combustion chamber of said engine is avoided. - View Dependent Claims (14, 15, 16)
-
-
17. An EGR system for a vehicle equipped with a diesel engine having an intake manifold and an exhaust manifold comprising:
-
a turbocharger having a compressor for supplying combustion air to the intake manifold and a turbine operatively connected to the compressor for receiving exhaust gases from the exhaust manifold to operate the compressor;
an exhaust particulate filter downstream of and in fluid communication with the outlet of the turbine for removing particulate matter from the exhaust gases;
an intake air filter upstream of the compressor for supplying filtered combustion air to the compressor;
a low pressure EGR line extending from an inlet downstream of the turbine to an outlet upstream of the compressor and downstream of the air filter;
an intercooler downstream of the compressor for cooling compressed combustion air and re-circulated exhaust gases to temperatures equal to or below the dew point of at least one of the combustion air and re-circulated exhaust gases, the intercooler having a reservoir for collecting condensation and a valve for removing collected condensed water from the reservoir whereby injection of liquid in the form of water, nitric and sulfuric acids formed by reaction of condensed water with the exhaust gases into the combustion chamber of the engine is avoided; and
,a liquid sensor in the reservoir and an electronically actuated valve operable when the reservoir is under positive pressure and in response to set liquid sensor readings to drain the reservoir.
-
Specification