Internal-combustion engines – Cooling – Multiple cylinders with equalized cooling
Reexamination Certificate
2002-08-15
2004-03-02
Kamen, Noah P. (Department: 3747)
Internal-combustion engines
Cooling
Multiple cylinders with equalized cooling
C123S041290
Reexamination Certificate
active
06698388
ABSTRACT:
CROSS REFERENCE TO RELATED APPLICATION
This application claims the benefit of United Kingdom patent application number 0120052.6, filed Aug. 16, 2001, and entitled “Internal Combustion Engine Cooling”.
BACKGROUND AND SUMMARY OF THE INVENTION
This invention relates to the cooling of internal combustion engines. More particularly the invention relates to a method of cooling an internal combustion engine, to an internal combustion engine assembly including a cooling system, and to an internal combustion engine body incorporating passageways for coolant.
In a conventional internal combustion engine, it is common to provide passageways in the engine body, and to pass coolant through those passageways during operation of the engine to prevent the engine body from overheating. In a typical arrangement, coolant is heated as it passes through the engine body and is then cooled by being passed through a heat exchanger, such as a radiator, before being passed through the engine body again.
Such a cooling system is simple and economical but is also relatively inflexible. In a typical internal combustion engine body, some regions of the engine body are likely to receive relatively large amounts of heat during operation of the engine. The flow rate of the coolant needs to be sufficient to avoid overheating of the engine body in these regions, but may result in other parts of the engine body being cooled to a lower temperature than is necessary or desirable, because of the high flow rate of the coolant, and may also lead to an excessive amount of power being required to circulate the coolant. The situation is further complicated because the various regions of the engine body may receive different amounts of heat according to the condition of the engine and/or the conditions under which it is operating.
It is an object of the invention to provide a method of cooling an internal combustion engine.
It is a further object of the invention to provide an improved internal combustion engine assembly.
It is a still further object of the invention to provide an improved internal combustion engine body.
According to the invention there is provided a method of cooling an internal combustion engine, including the steps of:
(a) providing a circulating primary flow of coolant through passageways in the engine body and a pump, the coolant being heated by the engine body as it flows through the passageways and being cooled after its passage through the engine body,
(b) providing a secondary flow of coolant by removing coolant from the primary flow and injecting it into and mixed with the primary flow at a predetermined location in the engine body,
(c) monitoring a variable that provides an indication of the temperature of the engine body in the region where the secondary flow of coolant mixes with the primary flow of coolant, and
(d) controlling the injection of the secondary flow of coolant into the primary flow in dependence upon the indicated temperature.
The invention further provides an internal combustion engine assembly including:
an engine body and passageways in the engine body defining a flow path for a primary flow of coolant through the engine body,
a pump for generating the primary flow of coolant,
a passage in the engine body leading into the flow path of the primary flow of coolant for enabling a secondary flow of coolant to be injected into and mixed with the primary flow at a predetermined location in the engine body,
a sensing device for sensing a variable that provides an indication of the temperature of the engine body in the region where the secondary flow of coolant mixes with the primary flow of coolant, and
a control system for controlling the injection of the secondary flow of coolant into the primary flow in dependence upon a signal from the sensing device.
The invention still further provides an internal combustion engine body including:
passageways in the engine body defining a flow path for a circulating primary flow of coolant through the engine body,
a passage in the engine body leading into the flow path of the primary flow of coolant for enabling a secondary flow of coolant to be injected into and mixed with the primary flow at a predetermined location in the engine body, and
a temperature sensing device in the region where the secondary flow of coolant mixes with the primary flow of coolant.
By injecting a secondary flow of coolant into the primary flow, it is possible to increase the heat transfer from the engine body to the coolant, and a substantially greater cooling effect in the region of the injection can be obtained by a flow rate of the sum of the primary and secondary flows as compared with the same flow rate provided as a primary flow only. Thus, the power required to circulate the coolant can be reduced, leading to reduced fuel consumption. Furthermore, by assessing the temperature in the region of the enhanced cooling effect and controlling the secondary flow in response to that assessment, it becomes possible not only to achieve greater cooling but also to achieve better control of cooling and, in particular, to provide controlled cooling at different and variable levels in one or more localized regions of the engine body. For example, the secondary flow can be injected into a region of the engine body that otherwise would be particularly hot and can thereby maintain that part of the engine body at a lower temperature, while other parts of the engine body where the cooling from the primary flow is already more than adequate are not cooled any further. By maintaining the various parts of the engine body closer to their ideal temperature, emissions can be reduced and engine component integrity and durability improved. Furthermore, the secondary flow of coolant, and if desired also the primary flow, can be arranged not to be initiated during cold start conditions, thereby saving power and leading to a faster warm-up of the engine and reduction in emissions. Also, the injection of the secondary flow into the primary flow can be employed to reduce any tendency of the coolant to boil in a particular location. Not only may the secondary flow reduce the temperature of the primary flow but it may also, more significantly in terms of avoiding boiling, increase the pressure of the coolant in the region of injection.
Thus, in summary the invention enables much improved control of engine body temperatures while at the same time enabling overall coolant flow rates to be reduced.
The flow velocity of the secondary flow of coolant is preferably substantially greater than the flow velocity of the primary flow of coolant prior to the mixing of the flows, although the volume flow rate (or mass flow rate) of the secondary flow of coolant injected into the primary flow is preferably substantially less than the volume flow rate (or mass flow rate) of the primary flow of coolant into which the secondary flow is injected. Preferably the flow velocity of the secondary flow is at least twice the flow velocity of the primary flow prior to mixing of the flows. Also, preferably the volume flow rate of the secondary flow of coolant injected into the primary flow is less than half the volume flow rate of the primary flow of coolant into which the secondary flow is injected.
The secondary flow of coolant is injected into the primary flow as a jet. It is believed that a factor in enhancing the cooling effect in the region of the injection of the secondary flow is that turbulence is created in the coolant and, as a result, heat transfer between the coolant and the engine body is enhanced. Preferably, the jet is directed through the primary flow onto a surface of the engine body. In that case, the boundary layer of coolant flowing along the passageway is disrupted and either destroyed or significantly reduced in thickness, thereby enhancing the heat transfer between the coolant and the engine body.
The cross-sectional area of the passageway for primary flow and of the passagway for secondary flow will be dependent upon the size of the engine cylinders. In the case of an engine for a road vehicl
Brace Christian John
Campbell Niall Andrew Fraser
Gouldson Iaim
Haigh Mathew
Hawley John Gary
Brinks Hofer Gilson & Lione
Kamen Noah P.
Visteon Global Technologies Inc.
LandOfFree
Internal combustion engine cooling system does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Internal combustion engine cooling system, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Internal combustion engine cooling system will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3246100