GB2495932A

GB2495932A - Delivery of two phase engine coolant by a matrix

Info

Publication number: GB2495932A
Application number: GB1118417.3A
Authority: GB
Inventors: Andrew Morgan Williams; Robert Michael Mcdavid; Antonis Dris; James D Wotherspoon
Original assignee: Perkins Engines Co Ltd; Caterpillar UK Engines Co Ltd; Caterpillar Inc
Current assignee: Perkins Engines Co Ltd; Caterpillar UK Engines Co Ltd; Caterpillar Inc
Priority date: 2011-10-25
Filing date: 2011-10-25
Publication date: 2013-05-01
Anticipated expiration: 2031-10-25
Also published as: WO2013061017A1; GB201118417D0; GB2495932B; CN104040135A; US20140261257A1

Abstract

A two phase (liquid and vapour) cooling system for an internal combustion engine has a coolant delivery matrix 27 in a cylinder block 25, the matrix having pipes 29 with apertures 30 for spraying liquid coolant at a cylinder wall extending from a manifold 28 around the cylinders. Manifold 28 also has apertures 30, and block 25 can have an oil cooler (44, fig 6) in a liquid coolant reservoir (43, fig 6). Some coolant can also pass through angled holes (35, fig 6) in a fire deck (34, fig 8) on to a mid deck (33, fig 8) and exhaust passages (21, fig 8).

Description

ENGINE COOLING SYSTEM

TECHNICAL FIELD

The present disclosure relates to improvements in

cooling systems for internal combustion engines, and in particular to a two phase (vapour) cooling system for an internal combustion engine.

BACKGROUND

Known internal combustion engines typically have at least one combustion chamber in which a piston is reciprocally moveable. The piston is drivably connected to a crankshaft via a connecting rod. One end of the combustion chamber typically has at least one intake port and an associated intake valve and at least one exhaust port with an associated exhaust valve. Generally, the intake and exhaust ports are provided in a cylinder head. A four stroke internal combustion engine may have an intake stroke in which the intake valve may open an intake port and the combustion chamber may be brought into fluid connection with an air intake system. During the intake stroke, the piston in the combustion chamber may move away from the cylinder head and thus, fresh combustion air may be sucked into the combustion chamber. Subseguently, the piston reverses its direction and moves towards the cylinder head for making a compression stroke.

During the compression stroke the intake valve and the exhaust valve are closed. At a certain moment during the compression stroke fuel is injected into the combustion chamber. Next, the fuel/air-mixture in the combustion chamber combusts and the piston motion is reversed and the power stroke takes place. During this power stroke, the combustion energy produced may be converted into kinetic energy of increased piston movement which is transferred to rotation of the crankshaft. After the power stroke, the piston movement reverses its direction and moves towards the cylinder head for making an exhaust stroke. During the exhaust stroke, normally, the intake valves are closed and the exhaust valves are opened.

Engine cooling is necessary to avoid high temperature damage to engine materials and lubricants. Internal combustion engines operate at temperatures higher than the melting temperature of engine materials, and hot enough to set fire to lubricants. Engine cooling removes energy fast enough to keep temperatures low so that the engine is not damaged.

In many conventional cooling systems a liguid coolant is pumped into a coolant jacket surrounding the cylinder head where the liguid coolant becomes heated. As the heated liquid leaves the engine, it is passed through a heat exchanger, such as a radiator equipped wIth a fan, which cools the liquid. The cooled liquid is then recirculated back into the engine.

In recent years the developments in Internal combustion technology have been focussed on reducing fuel consumption and exhaust emissions, however this can lead to a decrease in the thermal efficiency of the engine. A number of improved cooling and exhaust heat recovery systems have been proposed to reduce cooling loss and provide additional power from waste heat. Some such systems use two (or dual) phase, or vapour, cooling, examples of which are described in US-B- 5199387 and EP-A-0579553.

In such a system the cociant fluid is present in the engine in twc phases, namely the liquid and vapour phases.

The ccclant is in its liquid phase during engine warm up and is heated by the engine to its boiling point. At this point the coolant generates vapour and the resulting coolant liquid and coolant vapour are separated with the vapour being directed to a condenser to be condensed before being returned in liguid phase to the engine.

It has also become apparent that the separate phases can be used in a manner which optimises the thermal energy recovery and that the coolant can be returned to the engine as a mixture of both phases.

Such cooling systems may advantageously offer more rapid engine warm up, a reduction in the coolant mass flow, and therefore a reduction in the coolant system and radiator size, a reduction In coolant pumping power and an increase in the amount of waste energy available for thermal energy recovery systems.

The present disclosure is directed to further

improvements in the existing technology.

SUMMARY

The present disclosure therefore provides a coolant delivery matrix adapted for location in an engine housing, said matrix having at least one aperture being directed to spray liquid coolant at parts of an engine.

The present disclosure further provides a cooling

system for an internal combustion engine, said cooling system comprising:-the aforesaid coolant delivery matrix; a supply pump fluidly connected to supply liquid coolant under pressure to the coolant delivery matrix; an extraction pump adapted to extract vaporised coolant from the engine housing; and a condenser fluidly connected upstream to the extraotion pump and downstream to the supply pump.

The present disclosure further provides an internal combustion engine comprising a housing provided with a plurality of cylinders located in a cylinder block and a cylinder head attached to the cylinder block, and the aforementioned cooling system, wherein the coolant delivery matrix is located in the cylinder block and the apertures are directed to spray liquid coolant at parts of the cylinder block and cylinder head.

The present disclosure further provides a method of cooling an internal combustion engine, said internal combustion engine, said method comprising the steps of:-providing liquid coolant to a housing of the engine under pressure; spraying a plurality of jets of liquid coolant onto parts of the engine inside the housing; extracting vaporised coolant from engine housing; condensing the vaporised coolant into liquid coolant; and recirculating the condensed liquid coolant to the engine housing.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is schematic of an exemplary embodiment of an internal combustion engine; Figure 2 is a schematic of a cooling system for an internal combustion engine such as that illustrated in Figure 1; Figure 3 is a perspective view of the cylinder block of the internal combustion engine of Figure 1 with a front section of the cylinder block wall, and the cylinder head, removed to show the coolant delivery matrix; Figure 4 Is a plan view of the cylinder block of Figure 3 with the cylinder head removed; Figure 5 is a front cross sectional elevation through a pipe of the coolant delivery matrix of Figure 3; Figure 6 is a front cross sectional elevation of the connection of the coolant delivery matrix to the cylinder block; Figure 7 is a plan view showing the feeds into the cylinder head from the underlying cylinder block illustrating target points for the coolant; and Figure 8 is a front cross sectional elevation through an upper section of the cylinder block and cylinder head.

DETAILED DESCRIPTION

The present disclosure is directed towards a two phase (vapour) cooling system for an internal combustion engine in which a liquid coolant is sprayed towards hot spots in the cylinder block and cylinder head. The liguid coolant vaporises on contact with the hot engine parts and the resulting coolant vapour is extracted from the cylinder block and cylinder head for condensing and recycling.

Referring to Figure 1, there is shown a simplified schematic illustration of an exemplary internal combustion engine 10. The engine 10 typically comprises an engine housing 11 in which a plurality of cylinders 12 are located, in each of which is mounted a piston 13, which is able to move in a reciprocating manner therein. Fuel injectors 14 are located so as to extend at least partially into each of cylinders 12 and are operable to inject fuel directly into the cylinders 12 ahead of the pistons 13. As the pistons 13 move towards the injectors 14 they compress the fuel, which ignites and forces the piston 13 back in the opposite direction. Each piston 13 may be coupled to a crankshaft 15, by means of a piston rod 16, to enable rotation of crankshaft 15 as the pistons 13 reciprocate in the cylinders 12. The fuel may be supplied by a high pressure pump 17, which supplies pressurised fuel to a pressurised fuel source, such as a common rail 18, which in turn is fluidly connected to supply fuel to the fuel injectors 14.

Referring also to Figure 2 air is supplied to the engine 10 by means of an air intake conduit 19, which is connected to an intake manifold 20 which distributes the air to the cylinders 12, via intake ports (not shown) , for the combustion process. The engine 10 may also include one or more exhaust passages 21 extending from exhaust ports (not shown) in the engine housing 11 for conducting the exhaust away from the cylinders 12. The exhaust passages 21 may supply exhaust gas via an exhaust conduit 22 to a high pressure turbocharger 23. The exhaust conduit 22, in which the high pressure turbocharger 23 is located, is connected to the exhaust system to provide the exhaust gas flow.

Figure 2 is a schematic representation of one embodiment of a cooling system 24 for an internal combustion engine 10 such as that illustrated in Figure 1. It is to be understood that the cooling system 24 is suitable for use with a variety of other designs of internal combustion engine, other than the one illustrated herein.

Referring to Figures 3 to 8 the engine 10 is cooled by means of a coolant 41 which has a liquid form at room temperature. One suitable coolant 41 may be substantially water possibly with some anti-corrosive additives making up a small proportion. The coolant 41 is supplied to the cylinder block 25 in which the cylinders 12 are located. A cylinder head 31 may be attached to the cylinder block 25 by a plurality of bolts screwed into bosses 26 in the cylinder block 25 (see Figures 3 and 4) . A head gasket 32 may be located between the cylinder head 31 and cylinder block 25 to seal the joint therebetween. The cylinder head 31 may comprise 3 decks, namely a top deck (not shown), a mid-deck 33 and a fire deck 34 (see Figure 8) . The fire deck 34 generally overlies the cylinder block 25.

The fuel injectors 14 may pass through apertures 45,46 in the decks of the cylinder head 31. Where the fuel injectors 14 pass through the upper deck and fire deck 34, a seal may be created between the fuel injector 14 and the apertures 46. However where the fuel injectors 14 pass through the mid-deck 33, a gap is left between the fuel injector 14 and the mid-deck 33.

The coolant 41 is distributed within the cylinder block by a tubular coolant delivery matrix 27. The coolant delivery matrix 27 is designed to direct jets of liguid coolant 41 under pressure at engine hot spots, such as the walls of the cylinders 12 or areas of the fire deck 34 of the cylinder head 31. The matrix 27 may be formed from a manifold 28, which may encircle the cylinders 12 inside the cylinder block 25 and a plurality of pipes 29 which may extend from the manifold 28. The number of pipes 29 may he limited by the effect on the engine pressure. The greater the number of pipes 29 there are in the matrix 27, the greater the coolant pressure drop is across the engine 10.

Less pressure means that the "spray" strength of the coolant 41 will be adversely affected. The matrix 27 may also be of a different design to that illustrated, which enables the coolant 41 to be delivered tc the desired locations. In one embodiment the matrix 27 is cast, although it may be manufactured in any suitable manner from any suitable material.

The pipes 29 may have at least one aperture 30 extending through their sidewalls from the internal bores thereof, which enable pressurised jets or a spray of liguid coolant 41 to be directed into the cylinder block 25 around the cylinders 12 and at the walls of the cylinders 12.

Whilst a sufficient number of apertures 30 need to be provided to generate an effective spray of coolant 41, again the number of apertures 30 may be limited so as not to adversely affect the coolant pressure. The manifold 28 may also have one or more apertures 30 to assist in the distribution of the liguid coolant 41 onto the cylinder walls.

The fire deck 34 of the cylinder head 31 may be provided with a plurality of compound angled holes 35, each of which may cooperate with the bore of one of the pipes 29.

A liquid coolant reservoir 43 may be located in the cylinder block 25, which may comprise an oil cooler 44 for cooling the liquid coolant 41 before it passes into the matrix 27 via a suitable conduit 45 (see Figure 6) -A coolant vapour conduit 36 may be fluidly connected to the cylinder head 31 and a scavenging pump 37 may be located in the conduit 36. Downstream from the water pump 37 may be a condenser 38. A return pump 39 may be provided in a return conduit 40 which may extend from the condenser 38 to the manifold 28 of the coolant delivery matrix 37 in the cylinder block 25.

INDUSTRIAL APPLICABILITY

When the engine 10 is started from cold, the coolant 41 in the cooling system 24 is in liquid phase and remains in liquid phase during engine warm up. Whilst the engine 10 is running the pumps 37, 39 operate to maintain a continuous flow of liquid coolant 41 to the cylinder block 25. Liquid coolant 41 is pumped into the manifold 28 of the coolant delivery matrix 27 in the cylinder block 25 and circulates round the manifold 28 and into the pipes 29. Some of the liquid coolant 41 is sprayed out of the apertures 30 in the manifold 28 and the pipes 29 (as shown by the dotted arrows in Figure 4), the apertures being angled so that the jets spray on the walls of the cylinders 12. When the engine 10 has warmed up, the walls of the cylinders 12 will be of a temperature to cause the liquid coolant 41 to vaporise on contact to form coolant vapour 42, the evaporation process effecting cooling the walls of the cylinders 12.

-10 -At the same time jets of liquid coolant 41 may also pass through the multiple holes 35 in the fire deck 34.

These holes 35 are angled to direct the fluid flow towards the mid deck 33 and the underside of the exhaust passage 21 (as shown by the straight arrows in Figure 8) which are known hot spots of the engine 10. Some of the liquid coolant 41 vaporises on contact with the mid deck 33 and exhaust passage 21, whilst some of the liquid coolant 41 sprays down onto the tire deck 34, where further vaporisation occurs.

The liquid coolant 41 is targeted at the known hot spots in the engine 10, which may be the small gaps between the valves and ports.

The coolant vapour 42 is drawn from the cylinder block 25 and cylinder head 31, as a result of suction created by the pump 37. Some of the coolant vapour 42 (shown by the curly arrows in Figure 8) passes into the upper section of the cylinder head 31 via the gaps around the fuel injectors 14, where it passes into the coolant vapour conduSt 36.

Coolant vapour 42 from below the fire deck 34 passes into the coolant vapour conduit 36 from another collection point.

The coolant vapour 42 is then directed through the condenser 38 and is condensed to its liquid phase to form liquid coolant 41. The liquid coolant 41 is recirculated back to the cylinder block 25 by means of the return pump 39, where the aforementioned process repeats.

The cooling system 10 thus provides a continuous process of introduction of sprays of coolant liquid 41 into the cylinder block 25 and cylinder head 31 being directed at known hot spots therein and extraction of the cooant vapour 42. The sprayed coolant liquid 41 may be specifically -11 -targeted at areas of the engine for specific cooling requirements.

Claims

<claim-text>-12 - CLAIMS: - 1. A coolant delivery matrix adapted for location in an engine housing, said matrix having at least one aperture being directed to spray liquid coolant at parts of an engine.</claim-text> <claim-text>2. A coolant delivery matrix as claimed in claim 1 further comprising a plurality of pipes, said pipes having at least one aperture, said apertures being directed to spray liquid coolant at parts of an engine.</claim-text> <claim-text>3. A coolant matrix as claimed in claim 2 wherein said pipes have an open end.</claim-text> <claim-text>4. A coolant delivery matrix as claimed in any one of the preceding claims further comprising a manifold and said plurality of pipes extend from said manifold, and said pipes each having at least one aperture extending through a side wall of the pipe from a central bore.</claim-text> <claim-text>5. A coolant delivery matrix system as claimed in any one of claims 2 to 4 in which the pipes each have a plurality of apertures.</claim-text> <claim-text>6. A coolant delivery matrix as claimed in claim 4 or claim 5 where dependant on claim 4in which a plurality of apertures are provided in said manifold.</claim-text> <claim-text>7. A cooling system for an internal combustion engine, said cooling system comprising:-the coolant delivery matrix of any one of the preceding claims; -13 -a supply pump fluidly connected to supply liquid coolant under pressure to the coolant delivery matrix; an extraction pump adapted to extract vaporised coolant from the engine housing; and a condenser fluidly connected upstream to the extraction pump and downstream to the supply pump.</claim-text> <claim-text>8. An internal combustion engine comprising a housing provided with a plurality of cylinders located in a cylinder block and a cylinder head attached to the cylinder block, and a cooling system as claimed in claim 7, whereIn the coolant delivery matrix is located in the cylinder block and the apertures are directed to spray liquid coolant at parts of the cylinder block and cylinder head.</claim-text> <claim-text>9. An internal combustion engine as claimed in claim 8 in which the pipe and/or manifold apertures are directed at walls of the cylinders.</claim-text> <claim-text>10. An internal combustion engine as claimed in claim 8 or claim 9 in which the cylinder head comprises a fire deck in which are provided a plurality of openings which cooperate with the open ends of the said pipes to provide a passageway for liquid coolant to be sprayed into the cylinder head.</claim-text> <claim-text>11. An internal combustion engine as claimed in claim 10 in which the fire deck openings are directed at a mid deck of the cylinder head and/or an exhaust conduit extending from the cylinder head.</claim-text> <claim-text>12. An internal combustion engine as claimed in claim 11 further comprising a plurality of fuel injectors arranged to inject fuel into the cylinders, wherein each of said fuel -14 -injectors extends through an aperture in the mid deck with a gap between the fuel injector and the mid deck providing a passageway for vaporised coolant to pass into an upper section of the cylinder head.</claim-text> <claim-text>13. A method of cooling an internal combustion engine, said internal combustion engine, said method comprising the steps of: -providing liquid coolant to a housing of the engine under pressure; spraying a plurality of jets of liquid coolant onto parts of the engine inside the housing; extracting vaporised coolant from engine housing; oondensing the vaporised coolant into liquid cociant; and recirculating the condensed liquid coolant to the engine housing.</claim-text> <claim-text>14. A method as claimed in claim 13 in which the internal combustion engine comprises a plurality of cylinders located in a cylinder block and a cylinder head attached to the cylinder block and the plurality of jets of liquid coolant are sprayed at parts of the cylinder block and cylinder head.</claim-text> <claim-text>15. A method as claimed in claim 13 or claim 14 further comprising spraying a plurality of jets of liquid coolant into the cylinder head.Amendments to the claims have been filed as follows: CLAIT4S:- 1. A coolant delivery matrix configured for location in the cylinder block of an engine housing, said matrix comprising a manifold and a plurality of pipes extending from said manifold, said matrix being configured to locate around at least one cylinder in the cylinder block, said pipes having at least one aperture being directed to spray liquid coolant at a wall of the at least one cylinder.
2. A coolant matrix as claimed in claim 1 wherein said pipes have an open end.
3. A coolant delivery matrix as claimed in any one of the r 15 preceding claims in which the at least one aperture extends through a side wall of the pipe from a central bore.C\J
4. A coolant delivery matrix system as claimed in any one 0 of the preceding claims in which the pipes each have a plurality of apertures.
5. A coolant delivery matrix as claimed in any one of the preceding claims in which a plurality of apertures are provided in said manifold.
6. A cooling system for an internal combustion engine, said cooling system comprising:-the coolant delivery matrix of any one of the preceding claims; a supply pump fluidly connected to supply liquid coolant under pressure to the coolant delivery matrix; an extraction pump adapted to extract vaporised coolant from the engine housing; and a condenser fluidly connected upstream to the extraction pump and downstream to the supply pump.
7. An internal combustion engine comprising a housing provided with a plurality of cylinders located in a cylinder block and a cylinder head attached to the cylinder block, and a cooling system as claimed in claim 6, wherein the coolant delivery matrix is located in the cylinder block and the apertures are directed to spray liquid coolant at parts of the cylinder block and cylinder head.
8. An internal combustion engine as claimed in claim 9 in which the pipe and/or manifold apertures are directed at (\J walls of the cylinders. r 159. An internal combustion engine as claimed in claim 7 or claim 8 in which the cylinder head comprises a fire deck in C'J which are provided a plurality of openings which cooperate 0 with the open ends of the said pipes to provide a passageway for liquid coolant to be sprayed into the cylinder head.10. An internal combustion engine as claimed in claim 9 in which the fire deck openings are directed at a mid deck of the cylinder head and/or an exhaust conduit extending front the cylinder head.11. An internal combustion engine as claimed in claim 10 further comprising a plurality of fuel injectors arranged to inject fuel into the cylinders, wherein each of said fuel injectors extends through an aperture in the mid deck with a gap between the fuel injector and the mid deck providing a passageway for vaporised coolant to pass into an upper section of the cylinder head.12. A method of cooling an internal combustion engine, said internal combustion engine, said method comprising the steps of:-providing liquid coolant under pressure to the coolant delivery matrix of any one of claims 1 to 5 located in a housing of the engine; spraying a plurality of jets of liquid coolant onto parts of the engine inside the housing; extracting vaporised coolant from engine housing; condensing the vaporised coolant into liquid coolant; and recirculating the condensed liquid coolant to the (\J engine housing. T 1513. A method as claimed in claim 12 in which the internal combustion engine comprises a plurality of cylinders located C\J in a cylinder block and a cylinder head attached to the 0 cylinder block and the plurality of jets of liquid coolant are sprayed at parts of the cylinder block and cylinder head.14. A method as claimed in claim 12 or claim 13 further comprising spraying a plurality of jets of liquid coolant into the cylinder head.</claim-text>