This application claims priority to and the benefit of Korean Patent Application No. 10-2009-0102926 filed in the Korean Intellectual Property Office on Oct. 28, 2009, the entire contents of which application is incorporated herein for all purposes by this reference.
1. Field of the Invention
The present invention relates to an exhaust heat recirculation apparatus, and more particularly to an exhaust heat recirculation apparatus that is capable of improving fuel mileage by heating a lubricant using exhaust heat.
2. Description of the Related Art
Generally, because the temperature of a lubricant cannot quickly reach an appropriate temperature at start-up of an engine, friction loss occurs at each a friction surface of the engine, and thereby fuel mileage is deteriorated by the friction loss and noxious materials are exhausted to atmosphere.
To solve the problem, an apparatus heating the lubricant using an electric heater mounted at the lubricant while being submerged therein is well known to a person skilled in the art, however, the apparatus has drawbacks of discharging a battery mounted interior or exterior to a vehicle, and a battery having a greater capacity is required.
The information disclosed in this Background of the Invention section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.
The present invention has been made in an effort to provide an exhaust gas recirculation apparatus having advantages of improving fuel mileage at a low speed, i.e., at an early stage of running an engine, by performing heat exchange between oil and exhaust gas so as to maintain high-temperature oil of the engine.
The exhaust gas recirculation apparatus having a heat exchanger that is mounted at an exhaust line of an engine for heating coolant by the exhaust gas, may include a main line inducing exhaust gas exhausted from each cylinder of the engine to communicate to an exhaust gas inlet, a bypass line communicated to a downstream side of the main line, a bypass valve mounted inside the bypass line, and a heat exchanger selectively communicated to the bypass line by the bypass valve.
The heat exchanger may further include an oil circulation passage disposed therein in a serpentine shape.
Further, one end of the bypass line may communicate with the main line, an exhaust port is formed at the other end thereof, and the exhaust gas is selectively supplied to the exhaust port or the heat exchanger by the bypass valve.
Further, the bypass valve may be one of a butterfly valve or a valve of a hinge type.
Further, the bypass valve may be controlled by a back pressure actuator using back pressure of an engine, or a solenoid valve.
Further, a fixing bracket may further be formed at one end of the bypass line.
The methods and apparatuses of the present invention have other features and advantages which will be apparent from or are set forth in more detail in the accompanying drawings, which are incorporated herein, and the following Detailed Description of the Invention, which together serve to explain certain principles of the present invention.
Reference will now be made in detail to various embodiments of the present invention(s), examples of which are illustrated in the accompanying drawings and described below. While the invention(s) will be described in conjunction with exemplary embodiments, it will be understood that present description is not intended to limit the invention(s) to those exemplary embodiments. On the contrary, the invention(s) is/are intended to cover not only the exemplary embodiments, but also various alternatives, modifications, equivalents and other embodiments, which may be included within the spirit and scope of the invention as defined by the appended claims.
As shown in
Herein, the engine may be employed in a conventional manner, and the structures are not shown. The engine will be described schematically as follows.
As shown in
Therefore, the lubricant passage supplies oil to a friction surface of the engine, a connecting portion of the piston and the connecting rod, and a connecting portion of the connecting rod and the crankshaft for lubricating.
As shown in
The exhaust gas inlet 110 is formed so that exhaust gas exhausted from the exhaust manifold of the engine flows into the main line 120.
Therefore, the exhaust gas generated from the engine flows into the exhaust gas inlet 110.
The exhaust gas having flowed through the exhaust gas inlet 110 flows into the main line 120.
Subsequently, the exhaust gas passes a bypass line 130 communicated with a downstream of the main line 130, and is exhausted to atmosphere through an exhaust gas outlet 134 disposed downstream of the bypass line 130.
Further, the heat exchanger 150 is provided to one end of the bypass line 130 so as to communicate therewith.
A bypass valve 132 is mounted at a middle portion of the bypass line 130, and the bypass valve 132 is selectively opened.
Thus, the exhaust gas is exhausted toward the exterior through the exhaust gas outlet 134 via the bypass line 130 when the bypass valve 132 is opened, but the exhaust gas is exhausted through the exhaust gas outlet 134 after it is diverted toward the heat exchanger 150 when the bypass valve 132 is closed.
Further, as shown in
The fixing bracket 135 is provided to the heat exchanger 150 by bolting etc. in order to easier change the heat exchanger 150 in case of malfunction.
Further, because an assembling or disassembling process of the heat exchanger 150 is frequent, it is required to facilitate the process with an engaging groove 136 of the fixing bracket 135 formed as a slit shape so that adjustment of a mounting position of the heat exchanger 150 is enabled.
As shown in
Further, an oil supply port 152 and an oil exhaust port 154 are respectively formed at the heat exchanger 150.
Therefore, the oil flows to the oil supply port 152 through an oil pipe 40, and is then exhausted through the oil exhaust port 154 via the oil circulation passage 151.
An oil pump (not shown) can be mounted at the oil circulation passage 151 in order to forcedly feed oil from an oil pan (not shown) of the engine to the heat exchanger 150, and an open/close valve (not shown) can be mounted downstream of the oil pump.
That is, the oil circulates between the oil pan and the heat exchanger 150 through the oil circulation passage 151 having an oil pump.
The oil circulation passage 151 is formed in a serpentine shape such that it is capable of efficiently exchanging heat between the inside of the heat exchanger 150 and exhaust gas passing through therein.
At this time, because flow resistance of the heat exchanger 150 is high in case of opening of the bypass valve 132, the exhaust gas directly flows through the exhaust gas outlet 134 rather than to the heat exchanger 150 so as to avoid heat exchange.
Further, in case of closing of the bypass valve 132, because all the exhaust gas flows through the heat exchanger 150, the temperature of the oil is increased due to heat exchange between the oil and the exhaust gas.
Herein, the bypass valve 132 may be a butterfly valve or a valve of a hinge type.
Further, an actuator using back pressure or a solenoid valve can be provided in order to operate the bypass valve 132.
Referring to
At this time, among the exemplary embodiments, detailed description about similar portions with reference to various embodiments of the present invention will be omitted.
Referring to
Herein, a gate valve 211 that is disposed at a front of an exhaust turbine (not shown) and that is selectively opened or closed may be provided to the exhaust manifold 210 so as to control heat exchange.
Turning to
Herein, the oil flows into the oil circulation passage 351, and the oil flows according to opening or closing of an opening/closing valve 352 for controlling heat exchange.
Turning to
At this time, the heat exchange is controlled by using a gate valve 421 that is independently provided.
Turning to
Turning to
As shown in
Further, a coolant passage 630 is formed so that it circulates nearly to the oil circulation passage 620.
That is, exhaust gas passes through the inside of the heat exchanger 601 and then the exhaust gas sequentially passes near the oil circulation passage 620 and the coolant passage 630.
At this time, first/second check valves 622 and 623 are respectively mounted in the exhaust gas passage 610, the oil circulation passage 620, and the coolant passage 630, and the heat exchange is selectively controlled according to opening or closing of the valves. At this time, a bypass valve 621 can be provided to the exhaust gas passage 610 for determining whether exhaust gas passes through the inside of the heat exchanger 601 or not.
That is, in the early stage of engine operation, the coolant and the oil quickly perform heat exchange for increasing the temperature of the coolant and the oil.
After the coolant and the oil reach predetermined temperatures, the heat exchange is stopped by using the valves 621, 622, and 623.
Turning to
As shown in
Herein, an exhaust gas passage 720 is formed inside the first heat exchanger 701 for circulating the exhaust gas, and the exhaust gas passage 720 and the oil circulation passage 710 are provided for performing heat exchange therebetween.
Further, a first check valve 711 is mounted in the oil circulation passage 710 for controlling flow of the oil, and a second check valve 712 that is selectively opened or closed for controlling flow of the exhaust gas is provided to the exhaust gas passage 720. At this time, the second check valve 712 can be a bypass valve as shown in
That is, in the early stage of engine operation, the first check valve 711 and the bypass valve 712 are opened for performing heat exchange between the oil and exhaust gas.
Even in the early stage of engine operation, if the temperature of the oil is higher than that of the coolant, the heat exchange is performed therebetween for quick warm-up.
Meanwhile, oil having passed through the first heat exchanger 701 passes through the second heat exchanger 702.
At this time, a coolant passage 730 is provided so that coolant circulates through the inside of the second heat exchanger 702.
Further, a third check valve 713 that is mounted in the coolant passage 730 is selectively opened or closed so as to control flow of the coolant.
That is, at a high speed of an engine, the first and third check valves 711 and 713 are opened so as to perform heat exchange between the oil and the coolant, and thereby the temperature of the oil is decreased.
Turning to
Herein, the exhaust gas recirculation apparatus according to various embodiments of the present invention, similar to the exhaust gas recirculation apparatus according to various embodiments of the present invention including that illustrated in
Herein, in the same fashion as described above, first, second, and third bypass valves 821, 822, and 823 are respectively mounted in the exhaust gas outlet 810, oil circulation passage 820, and the coolant passage 830, and then heat exchange is performed according to opening or closing of the valves.
However, as opposed to the exhaust gas recirculation apparatus according to various embodiments of the present invention, at a high speed of an engine, the oil and the coolant are diverted to an auxiliary heat exchanger 802 so as to perform heat exchange, and thereby the coolant more quickly cools the oil.
Therefore, the exhaust gas recirculation apparatus has an advantage of improving fuel mileage at a low speed, i.e., at an early stage of running an engine, by performing heat exchange between oil and exhaust gas so as to maintain high-temperature oil of the engine, and an advantage of reducing thermal resistance at a high speed of the engine by diverting the exhaust gas from the heat exchanger.
The foregoing descriptions of specific exemplary embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teachings. The exemplary embodiments were chosen and described in order to explain certain principles of the invention and their practical application, to thereby enable others skilled in the art to make and utilize various exemplary embodiments of the present invention, as well as various alternatives and modifications thereof. It is intended that the scope of the invention be defined by the Claims appended hereto and their equivalents.
Number | Date | Country | Kind |
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10-2009-0102926 | Oct 2009 | KR | national |