The present invention relates generally to engines and, more particularly, to cooling recirculated exhaust gases in engines.
In order to minimize pollutants such as NOX, internal combustion engines may include an exhaust gas recirculation (EGR) system that includes an EGR valve. EGR systems primarily recirculate exhaust gas by-products into the intake air supply of the internal combustion engine. The EGR valve can be used to redirect a portion of exhaust gases to an intake conduit, such as an intake manifold, so that the redirected exhaust gases will be recycled.
The exhaust gas which is reintroduced to the engine cylinder reduces the concentration of oxygen therein, which in turn lowers the maximum combustion temperature within the cylinder and slows the chemical reaction of the combustion process, decreasing the formation of nitrous oxides (NOx). Furthermore, the exhaust gases typically contain unburned hydrocarbons that are burned on reintroduction into the engine cylinder, further reducing the emission of exhaust gas byproducts that would be emitted as undesirable pollutants from the internal combustion engine.
In order to improve engine performance and reduce emissions of pollutants, it has been found to be advantageous to cool the exhaust gases that are being recirculated by the use of various devices, such as, for example, air-to-air coolers, water to air coolers, or other heat transfer devices. However, such devices require an increase in the overall heat rejection capability of the engine. For example, additional radiators and/or larger, more cumbersome radiators may be required in order to provide such an increased heat rejection capability, especially where the engine is used in a slow-moving vehicle or machine.
It is also known to use a device commonly known as a vortex tube or a Ranque-Hilsch tube in order to separate components of exhaust gases. For example, U.S. Pat. No. 3,566,610 discloses a method and apparatus for separating components of exhaust of an internal combustion engine by density using a vortex tube.
The present invention is directed to overcoming one or more of the problems or disadvantages associated with the prior art.
An engine is provided in accordance with the disclosure that may include an exhaust conduit, an intake conduit, and a vortex tube in fluid communication with the exhaust conduit and the intake conduit. The vortex tube may include an inlet port in fluid communication with the exhaust conduit, a cold gas outlet port in fluid communication with the intake conduit, and a hot gas outlet port.
In accordance with another aspect of the disclosure, an engine exhaust system is provided that may include an exhaust conduit, an intake conduit, and a vortex tube in fluid communication with the exhaust conduit and the intake conduit. The vortex tube may include an inlet port in fluid communication with the exhaust conduit, a cold gas outlet port in fluid communication with the intake conduit, and a hot gas outlet port.
In accordance with a still further aspect of the disclosure, a method of recirculating exhaust gases in an engine is provided. The engine may include a combustion chamber and the method may include diverting at least a portion of exhaust gases, cooling at least a portion of the diverted exhaust gases in a vortex tube, and reintroducing the cooled exhaust gases into the combustion chamber.
With reference to
The cold gas outlet 28 of the vortex tube 20 may be placed in fluid communication with a cold exhaust gas recirculation conduit 30 that in turn is in fluid communication with an intake air conduit 32. The intake air conduit 32 is in fluid communication with the intake manifold 12, and a venturi conduit 34 may be provided in the intake air conduit 32 to create a low-pressure region for drawing the relatively cold exhaust gases into the intake air conduit 32. An EGR valve 36 may be disposed in the cold exhaust gas recirculation conduit 30. The EGR valve 36 may be an on/off valve or a modulating valve, or any other suitable type of valve.
The hot gas outlet 26 of the vortex tube 20 may lead to a turbine section 38 of a turbocharger assembly 40. Alternatively, the hot gas outlet 26 may simply lead to an exhaust conduit 39 downstream of the turbine section 38 of the turbocharger assembly 40. A wastegate 41 may be provided to selectively divert exhaust gases in order to bypass the turbine section 38. The turbocharger assembly 40 may further include a compressor section 42 that is in fluid communication with the intake air conduit 32 via a compressor outlet conduit 44.
An electronic control unit (ECU) 46 may be used to electronically control the configuration of the bypass valve 24, the wastegate 41, and/or the EGR valve 36.
The ECU 46 may be operatively associated with one or more sensors, such as, for example a sensor 47, associated with the engine 10. The sensor 47 may be adapted, for example, to monitor the status of one or more of: the CO2 content of the exhaust gas, the O2 content of the exhaust gas, the NOx content of the exhaust gas, the intake mass air flow, the exhaust mass air flow, the EGR mass air flow, coolant temperature, engine speed, vehicle speed, altitude, and/or ambient air pressure. If desired, other sensors, such as pressure sensors and/or air flow rate sensors may be provided in one or more of the exhaust conduit 16, inlet 18 of the vortex tube 20, the bypass conduit 22, the hot gas outlet 26, the cold gas outlet 28, the cold exhaust gas recirculation conduit 30, the intake air conduit 32, and the venturi conduit 34. The ECU 46 may include a microprocessor and associated memory (not shown) adapted to provide the generation of appropriate control signals for use in controlling engine components such as, for example, the bypass valve 24, the EGR valve 36, the wastegate 41, and/or the flow reduction valve 50, based upon output signals received from the sensor 47 and/or other sensors.
A secondary cold exhaust gas conduit 48 may be provided in fluid communication with the cold exhaust gas recirculation conduit 30, and may include a flow reduction valve 50. The secondary cold exhaust gas conduit 48 and the flow reduction valve 50 may be used to divert a portion of the cold exhaust gas exiting from the cold gas outlet 28 to be reunited with the exhaust gases exiting from the hot gas outlet 26, and the flow reduction valve 50 may also be electronically controlled by the ECU 46.
With reference to
The cold gas outlet 128 of the vortex tube 120 may be placed in fluid communication with a cold exhaust gas recirculation conduit 130 that in turn is in fluid communication with an intake air conduit 145 that is upstream of the compressor section 42 of the turbocharger assembly 40. The venturi conduit 34 depicted in
A secondary cold exhaust gas conduit 148 may be provided in fluid communication with the cold exhaust gas recirculation conduit 130, and may include a flow reduction valve 150. The secondary cold exhaust gas conduit 148 and the flow reduction valve 150 may be used to divert a portion of the cold exhaust gas exiting from the cold gas outlet 128 to be reunited with the exhaust gases exiting from the hot gas outlet 126, and the flow reduction valve 150 may also be electronically controlled by the ECU 46.
The ECU 46 may be used to electronically control the configuration of the valves 150, 124, 136, and/or the waste gate 41, in a manner similar to that described above with respect to the embodiment of FIG. 1.
Again, referring to
The relatively cold exhaust gases exiting the vortex tube 20 at the cold gas outlet 28 may flow into the cold exhaust gas recirculation conduit 30, and/or may be directed via the secondary cold exhaust gas conduit 48, depending on the position of the flow reduction valve 50. If the EGR valve 36 is open, the cold exhaust gas is fed to the intake air conduit 32 and mixes with intake air in the venturi conduit 34.
Due to simplicity of the vortex tube 20, which requires no moving parts, an inexpensive, easy to maintain, and lightweight apparatus is provided for cooling the recirculated exhaust gases of the engine 10.
The embodiment of
Other aspects and features of the present invention can be obtained from a study of the drawings, the disclosure, and the appended claims.
Number | Name | Date | Kind |
---|---|---|---|
3019780 | Nuding | Feb 1962 | A |
3397682 | Riggan | Aug 1968 | A |
3566610 | Fiore | Mar 1971 | A |
3861142 | Bose | Jan 1975 | A |
3892070 | Bose | Jul 1975 | A |
4270508 | Lindberg | Jun 1981 | A |
4345572 | Suzuki et al. | Aug 1982 | A |
4426967 | McWhorter | Jan 1984 | A |
4503813 | Lindberg | Mar 1985 | A |
4587807 | Suzuki | May 1986 | A |
5193341 | Sibbertsen et al. | Mar 1993 | A |
5351669 | Herzog | Oct 1994 | A |
5461868 | Finko | Oct 1995 | A |
5617726 | Sheridan et al. | Apr 1997 | A |
6247460 | Lindberg et al. | Jun 2001 | B1 |
6502397 | Lundqvist | Jan 2003 | B1 |
6742335 | Beck et al. | Jun 2004 | B2 |
20040007220 | Sponton | Jan 2004 | A1 |
Number | Date | Country |
---|---|---|
2002070657 | Mar 2002 | JP |
2090774 | Sep 1977 | RU |