Patent Application
20130180240
The present invention relates to bypass arrangements and, more particularly, to bypass arrangements for bypassing waste heat recovery devices downstream of engines.
A major challenge in developing waste heat recovery systems for heavy and medium duty truck markets is in addressing the need for heat to be supplied to exhaust after treatment systems. For example, catalyst technologies used in these after treatments systems require heat to operate correctly and to regenerate. Waste heat recovery systems remove heat from the exhaust that would have otherwise flowed to the catalyst systems. Often it is necessary to dump heat to the catalyst system, rather than recover it, such as during, regeneration, when the catalyst must function at low engine load, or during cold engine operating conditions.
U.S. Patent Application Publication U.S.2005/0188682 to Fledersbacher discloses bypassing a variable geometry turbine when accelerated heating of a cleaning device in an exhaust gas train is desired. The inventors have recognized a disadvantage to such an arrangement in that bypassing the turbine impacts combustion in the engine. The inventors have further recognized the advantages of being able to avoid impacting combustion when it is desired to provide additional heat to a component in an exhaust gas line.
According to one aspect of the present invention, a waste heat recovery device bypass arrangement comprises a conduit having a first end and a second end adapted to connect upstream and downstream, respectively, of a waste heat recovery device, a valve in the conduit, the valve being controllable to open and close, and a controller arranged to control the valve to open in response to a first signal and close in response to a second signal.
According to another aspect of the present invention, a diesel engine arrangement comprises a diesel engine, a waste heat recovery device in a first conduit connected to the engine and arranged to receive exhaust gas from the engine, and a waste heat recovery device bypass arrangement, comprising a second conduit having a first end and a second end connected to the first conduit upstream and downstream, respectively, of the waste heat recovery device, a valve in the second conduit, the valve being controllable to open and close, and a controller arranged to control the valve to open in response to a first signal and close in response to a second signal.
According to yet another aspect of the present invention, a method for bypassing a waste heat recovery device comprises sensing a temperature of gas in a first conduit in which the waste heat recovery device is disposed, and, if the sensed temperature is below a first temperature, bypassing the waste heat recovery device.
The features and advantages of the present invention are well understood by reading the following detailed description in conjunction with the drawings in which like numerals indicate similar elements and in which:
The waste heat recovery device bypass arrangement 27 shown in
In the embodiments of
In the embodiments shown in
The first signal may be a signal from a sensor such as temperature sensor 43 associated with a device 45 downstream from the waste heat recovery device 23, such as a catalyst after treatment system, although the valve 39 may be controlled to open in response to signals relating to substantially anything of interest, such as a characteristic of the exhaust or the occurrence of an event such as the passage of time. For purposes of discussion here, however, the sensor will be a temperature sensor 43. The temperature sensor 43 may be disposed in the first conduit 25 upstream or downstream of the device 45, or in the device 45. When it is desired to operate or regenerate the catalyst after treatment system 45, if the temperature sensor 43 sends a signal that the temperature is too low for proper operation or regeneration, the controller 41 can control the valve 39 to open to bypass the waste heat recovery device 23 so that temperature downstream of the waste heat recovery device will increase. Like the first signal, the second signal may be a signal relating to anything of interest, such as a signal from the temperature sensor 43 that a desired temperature for operation or regeneration of the catalyst after treatment system 45 has been reached, or a signal from a timer (not shown) that may be part of the controller reflecting the passage of a predetermined amount of time. When used in conjunction with a device 45 such as a catalyst after treatment system in an exhaust line, the temperature sensor is ordinarily downstream of the waste heat recovery device 23 and, more particularly, downstream of the point where the second end 33 of the second conduit 29 meets the first conduit 25.
A second valve 47 adapted to restrict fluid flow through the waste heat recovery device 23 and controlled by the controller 41 to open in response to a third signal and close in response to a fourth signal can also be provided. In
The fourth signal to close the second valve 47 may be the same signal as the first signal that opens the valve 39, or some other signal, such as a signal from another temperature sensor remote from the temperature sensor 43. The third signal to open the second valve 47 may be the same signal as the second signal that closes the valve 39, or some other signal. The valve 39 and the second valve 47 may both be controllable to open and close to varying degrees, depending upon an amount of bypass desired. For example, the valves may be controlled to permit some flow through each of the bypass arrangement 27 and the waste heat recovery device 23.
If the second valve is omitted, it may he desirable to configure the bypass arrangement 27 in a manner to ensure that there is fluid flow through the bypass arrangement, such as by providing less resistance to flow through the bypass arrangement when the valve 39 is open than normally occurs through the waste heat recovery device.
A second valve 47″ adapted to restrict fluid flow through the waste heat recovery device 23 and controlled by the controller 41 to open in response to a third signal and close in response to a fourth signal can also be provided. The third and fourth signals may be the same signals as the second and first signals, respectively, or based on other characteristics or events. The second valve 47″ is illustrated as being disposed in the first conduit 25″ upstream of the waste heat recovery device 23 and downstream of the point where the first end 31″ of the second conduit 29″ meets the first conduit, however, the second valve may be located in or downstream of the waste heat recovery device. The second valve 47″ can close when the valve 39″ opens, to facilitate fluid flow through the bypass arrangement 27″, as opposed to through the waste heat recovery device 23.
In a method for bypassing a waste heat recovery device 23 according to an aspect of the present invention, a temperature of gas in a first conduit 25 in which the waste heat recovery device is disposed is sensed. If the sensed temperature is below a first temperature, such as a temperature required for operation or regeneration of a catalyst after treatment device 45, the waste heat recovery device 23 is bypassed. Bypassing of the waste heat recovery device 23 can be terminated after, for example, a predetermined time, such as a time needed for regeneration of the catalyst device 45, or after the sensed temperature is at or above a second temperature. The method can include bypassing a turbine 35 of a turbocharger 37 upstream of the waste heat recovery device 23 at the same time that the waste heat recovery device 23 is bypassed.
The waste heat recovery device 23 can be bypassed using the bypass arrangement 27 (or 27′ or 27″) by opening the valve 39 (or 39″) in a second conduit connected at a first end to the first conduit upstream of the waste heat recovery device 23 and connected at a second end to the first conduit downstream of the waste heat recovery device. The waste heat recovery device 23 may also be bypassed by closing a second valve 47 (or 47″) in the first conduit 25 (or 25″) upstream of the waste heat recovery device 23 in conjunction with opening of the valve 39 (or 39″).
In the present application, the use of terms such as “including” is open-ended and is intended to have the same meaning as terms such as “comprising” and not preclude the presence of other structure, material, or acts. Similarly, though the use of terms such as “can” or “may” is intended to be open-ended and to reflect that structure, material, or acts are not necessary, the failure to use such terms is not intended to reflect that structure, material, or acts are essential. To the extent that structure, material, or acts are presently considered to be essential, they are identified as such.
While this invention has been illustrated and described in accordance with a preferred embodiment, it is recognized that variations and changes may be made therein without departing from the invention as set forth in the claims.
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/US2010/051551 | 10/6/2010 | WO | 00 | 2/26/2013 |
