WO2024047274A1 - Cooling system for an internal combustion engine and piston engine - Google Patents

Cooling system for an internal combustion engine and piston engine Download PDF

Info

Publication number
WO2024047274A1
WO2024047274A1 PCT/FI2022/050577 FI2022050577W WO2024047274A1 WO 2024047274 A1 WO2024047274 A1 WO 2024047274A1 FI 2022050577 W FI2022050577 W FI 2022050577W WO 2024047274 A1 WO2024047274 A1 WO 2024047274A1
Authority
WO
WIPO (PCT)
Prior art keywords
flow
cooling
engine
duct portion
cooling circuit
Prior art date
Application number
PCT/FI2022/050577
Other languages
French (fr)
Inventor
Daniel HÄGGBLOM
Original Assignee
Wärtsilä Finland Oy
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Wärtsilä Finland Oy filed Critical Wärtsilä Finland Oy
Priority to PCT/FI2022/050577 priority Critical patent/WO2024047274A1/en
Publication of WO2024047274A1 publication Critical patent/WO2024047274A1/en

Links

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01P—COOLING OF MACHINES OR ENGINES IN GENERAL; COOLING OF INTERNAL-COMBUSTION ENGINES
    • F01P7/00—Controlling of coolant flow
    • F01P7/14—Controlling of coolant flow the coolant being liquid
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01P—COOLING OF MACHINES OR ENGINES IN GENERAL; COOLING OF INTERNAL-COMBUSTION ENGINES
    • F01P7/00—Controlling of coolant flow
    • F01P7/14—Controlling of coolant flow the coolant being liquid
    • F01P2007/143—Controlling of coolant flow the coolant being liquid using restrictions
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01P—COOLING OF MACHINES OR ENGINES IN GENERAL; COOLING OF INTERNAL-COMBUSTION ENGINES
    • F01P7/00—Controlling of coolant flow
    • F01P7/14—Controlling of coolant flow the coolant being liquid
    • F01P2007/146—Controlling of coolant flow the coolant being liquid using valves

Definitions

  • the invention concerns a cooling system for an internal combustion engine in accordance with claim 1 .
  • the invention also concerns a piston engine.
  • a high temperature (HT) circuit is used for controlling the temperature of the cylinder liners and the cylinder heads.
  • the HT circuit can also connected to the high temperature part of a double-stage charge air cooler.
  • the LT circuit typically serves at least the low-temperature part of the charge air cooler and a lube oil cooler.
  • Temperature in the HT circuit is, depending on the engine type, typically around 70-102 °C and in the LT circuit 38-60 °C.
  • a relatively high temperature in the HT circuit is desirable for ensuring safe ignition and combustion of low-quality heavy fuels also at low loads, for minimizing temperature fluctuations in the components of the cylinders and for preventing corrosion that can be caused by excessive cooling.
  • the pumps used for pressurizing the cooling liquid are typically impeller pumps. In a cooling circuit with an impeller pump, the flow depends on the pressure drop in the cooling circuit.
  • the cooling circuit can be provided with one or more flow restrictors.
  • the flow restrictors are typically orifice plates. The dimensions of the orifice determine the pressure drop over the orifice plate.
  • the cooling system When a new engine is delivered, the cooling system is provided with orifice plates providing the desired flow characteristics.
  • a problem of the orifice plates is that if adjustments are needed, the cooling circuit needs to be drained and part of the piping needs to be dismounted to replace one or more of the orifice plates by a different orifice plate, or to add or remove orifice plates. Summary of the invention
  • An object of the present invention is to provide an improved cooling system for an internal combustion engine.
  • the characterizing features of the cooling system according to the invention are presented in claim 1 .
  • Another object of the invention is to provide an improved piston engine, as defined in another claim.
  • the cooling system comprises at least one cooling circuit, in which cooling circuit cooling liquid can be circulated to cool down components of the engine and/or fluids flowing in the engine, at least one pump for pressurizing the cooling liquid circulated in said cooling circuit, and a flow restriction arrangement for adjusting the flow of cooling liquid in said cooling circuit.
  • the flow restriction arrangement comprises a first duct portion forming part of said cooling circuit and having a first cross-sectional area, a second duct portion located in said cooling circuit downstream from the first duct portion and having a second cross-sectional area that is greater than the first cross-sectional area, and a flow restrictor element that is moveable in the axial direction of the first duct portion and configured such that flow area past the flow restrictor element from the first duct portion to the second duct portion depends on the position of the flow restrictor element in the axial direction of the first duct portion.
  • the pressure drop over the flow restrictor element can be adjusted by moving the flow restrictor element. This allows adjusting the flow in the cooling circuit without draining the cooling circuit and dismounting any cooling liquid pipes. The flow could be adjusted even when the engine is running.
  • the flow restrictor element comprises a flow control portion, of which position determines the flow area past the flow restrictor element, and a shaft connected to the flow control portion for moving the flow control portion.
  • the flow control portion has a conical or frusto-conical shape having a tapered end facing the upstream side of the flow in the cooling circuit. Because of the shape of the flow control portion, the cooling liquid flows smoothly past the flow restrictor element and the risk of cavitation is reduced.
  • the flow restriction arrangement comprises a transition portion between the first duct portion and the second duct portion, the cross-sectional area of the transition portion increasing gradually in the flow direction of the cooling liquid. The transition portion of the cooling liquid duct facilitates smooth flow from the first duct portion to the second duct portion.
  • At least the second duct portion is arranged in a flow restriction block that is connectable to a cooling medium pipe of the cooling circuit.
  • the modular structure allows easy assembly of the flow restriction arrangement.
  • the flow restriction arrangement is arranged in the cooling circuit on the downstream side of the cylinder liners cooled by the cooling circuit.
  • the cooling circuit is a high-tem- perature cooling circuit of the engine.
  • the piston engine according to the invention comprises a cooling system defined above.
  • the flow restriction arrangement is attached to a side of the engine block.
  • Fig. 1 shows a cooling system according to an embodiment of the invention
  • Fig. 2 shows an engine with a flow restriction arrangement according to an embodiment of the invention
  • Fig. 3 shows a cross-sectional view of the flow restriction arrangement taken along line A-A of figure 1 .
  • FIG 1 is shown schematically a cooling system of an internal combustion engine 40.
  • the engine 40 is a large internal combustion engine, such as a main or an auxiliary engine of a ship or an engine that is used at a power plant for producing electricity.
  • the cylinder bore of the engine 40 is at least 150 mm.
  • Figure 1 shows an in-line engine, but the engine could also be a V-engine.
  • the engine 40 is provided with two turbochargers 45, 46.
  • a first turbocharger 45 is a low-pressure turbocharger and a second turbocharger 46 is a high-pressure turbocharger.
  • the turbochargers 45, 46 are connected in series. The pressure of the intake air of the engine 40 is raised in the low-pressure turbocharger 45 from the ambient pressure to a first pressure level and then in the high-pressure turbocharger 46 from the first pressure level to a second pressure level, which is higher than the first pressure level.
  • the intake air of the engine 40 could be pressurized also by a single turbocharger.
  • a V-engine could be provided with separate turbochargers for each bank of the engine.
  • a V-engine could thus be provided with two turbochargers arranged in parallel, or two low-pressure turbocharger arranged in parallel and two high-pressure turbochargers arranged in parallel.
  • the intake air of the engine 40 is cooled down between the low-pressure turbocharger 45 and the high-pressure turbocharger 46 and after the high-pressure turbocharger 46.
  • a low-pressure charge air cooler is arranged between the low-pressure turbocharger 45 and the high-pressure turbocharger 46.
  • the low-pressure charge air cooler comprises a first stage 47 and a second stage 48.
  • a high-pressure charge air cooler is arranged after the high-pressure turbocharger 46.
  • the high-pressure charge air cooler comprises a first stage 49 and a second stage 50.
  • the intake air is thus cooled down in two stages both between the turbochargers 45, 46 and downstream from the high-pressure turbocharger 46.
  • the two stages of the charge air coolers could also be separate charge air coolers.
  • the cooling system could also be provided with single stage cooling between the turbochargers 45, 46 and/or between the high-pressure turbocharger 46 and the engine 40.
  • the cooling system of the engine 40 comprises a high -temperature cooling circuit and a low-temperature cooling circuit.
  • the temperature of the cooling liquid is lower than in the high-temperature cooling circuit.
  • Temperature in the high -temperature cooling circuit is typically around 70-105 °C and in the low-temperature cooling circuit 35-55 °C.
  • the cooling liquid in the cooling circuits can be, for instance, water.
  • the cooling liquid can also contain additives, for example for preventing corrosion.
  • the cooling system comprises a cooling liquid pump 1 for circulating the cooling liquid in the cooling system.
  • the cooling liquid pump 1 can be, for instance, an impeller pump.
  • the cooling system comprises a single cooling liquid pump 1.
  • the cooling liquid pump 1 comprises a high- temperature portion 2 for pressurizing the cooling liquid circulated in the high- temperature cooling circuit and a low-temperature portion 3 for pressurizing the cooling liquid circulated in the low-temperature cooling circuit.
  • the cooling liquid pump 1 is provided with a common shaft 10 for driving both the high- temperature portion 2 and the low-temperature portion 3.
  • the cooling liquid pump 1 is mechanically coupled to the engine 40 to be driven by the engine.
  • the cooling system could be provided with separate low-temperature and high- temperature pumps.
  • the cooling liquid pump 1 comprises a first inlet 13, a second inlet 14 and a third inlet 17.
  • the first 13 and the second inlet 14 are inlets of the high-temper- ature portion 2 and the third inlet 17 is an inlet of the low-temperature portion 3.
  • the cooling liquid pump 1 further comprises a first outlet 16, which is an outlet of the high-temperature portion 2, and a second outlet 18, which is an outlet of the low-temperature portion 3.
  • the high-temperature cooling circuit is arranged to cool down at least the cylinder liners and the cylinder heads of the engine 40.
  • the cooling liquid flows from the high-temperature portion 2 of the cooling liquid pump 1 to the engine 40, where heat is transferred from the cylinder liners and the cylinder heads of the engine 40 to the cooling liquid.
  • a check valve 51 is arranged on the downstream side of the high-temperature portion 2 of the cooling liquid pump 1 to prevent backflow to the cooling liquid pump 1 .
  • the cooling liquid flows to a first by-pass valve 41.
  • the first by-pass valve 41 allows conducting the cooling liquid selectively either to the second inlet 14 of the high-temperature portion 2 of the cooling liquid pump 1 or to a first heat exchanger 42.
  • the first heat exchanger 42 is configured to cool down the cooling liquid received from the high-temperature cooling circuit. From the first heat exchanger 42, the cooled down cooling liquid is conducted to the second inlet 17 of the cooling liquid pump 1 , i.e. the inlet 17 of the low- temperature portion 3.
  • the first by-pass valve 41 can be used for controlling the temperature of the cooling liquid in the high-temperature cooling circuit. If the temperature is too low, hot cooling liquid can be conducted from the end of the high-temperature cooling circuit to the second inlet of the high-temperature portion 2 of the cooling liquid pump 1 to increase the temperature in the high-temperature cooling circuit. If the temperature is too high, the cooling liquid from the high-temperature cooling circuit can be conducted to the first heat exchanger 42.
  • the cooling system further comprises a second by-pass valve 43.
  • the second by-pass valve 43 allows by-passing the first heat exchanger 42 to conduct cooling liquid from the high-temperature cooling circuit to the inlet 17 of the low-temperature portion 3 of the cooling liquid pump 1 .
  • the cooling liquid is conducted to a second heat exchanger 44, where the cooling liquid is heated.
  • a check valve 52 is arranged between the low-temperature portion 3 of the cooling liquid pump 1 and the second heat exchanger 44 to prevent backflow to the cooling liquid pump 1.
  • the cooling liquid is conducted to the second stage 48 of the low-pressure charge air cooler, where heat is transferred from the intake air of the engine 40 to the cooling liquid.
  • the cooling liquid is conducted to the second stage 50 of the high- pressure charge air cooler, where heat is transferred from the intake air to the cooling liquid.
  • the cooling liquid is conducted to the first stage 49 of the high-pressure charge air cooler.
  • the first stage 49 of the high-pressure charge air cooler further heat is transferred from the intake air to the cooling liquid.
  • the cooling liquid is conducted to the first stage 47 of the low-pressure charge air cooler.
  • the temperature of the cooling liquid in the low-temperature cooling circuit is at its highest.
  • the cooling liquid is conducted to the first inlet 13 of the high-temperature portion 2 of the cooling liquid pump 1.
  • the cooling liquid is mixed with cooling liquid that is introduced into the high-temperature portion 2 through the second inlet 14.
  • Part of the cooling liquid from the low-temperature cooling circuit can flow to the first heat exchanger 42, where it is cooled down before being conducted through the second by-pass valve 43 to the inlet 17 of the low-temperature portion 3 of the cooling liquid pump 1 .
  • the low-temperature cooling circuit can be arranged to cool down also the lube oil of the engine.
  • a lube oil cooler could be arranged in the low-temperature cooling circuit, for instance, between the first stage 49 of the high-pressure charge air cooler and the first stage 47 of the low-pressure charge air cooler.
  • the cooling system could be configured also in many alternative ways.
  • the first stage 47 of the low-pressure charge air cooler could be arranged in the high-temperature cooling circuit.
  • the cooling circuits could also comprise by-pass ducts for one or more stages 47, 48, 49, 50 of the charge air coolers.
  • FIG. 1 shows a simplified illustration of a cooling system
  • the cooling system can comprise many additional components.
  • the cooling system can comprise a low-temperature stand-by pump and a high-temperature stand-by pump.
  • the stand-by pumps can be driven for circulating cooling liquid in the cooling system when the engine 40 is not running.
  • the flow of the cooling liquid in the high-temperature cooling circuit and/or the low-temperature cooling circuit can be adjusted by providing the cooling circuit with a flow restrictor causing a pressure drop.
  • the flow of the cooling liquid may need to be adjusted, for example, if the engine or cooling system configuration is changed. For instance, if a turbocharger of the engine is replaced by a different turbocharger or heat exchangers are changed, there may be a need to adjust the flow. Also, a change in the operating conditions may necessitate adjustment of the cooling liquid flow.
  • the cooling system is provided with a flow restriction arrangement 19.
  • the flow restriction arrangement 19 is arranged in the high-temperature cooling circuit downstream from the engine 40.
  • the flow restriction arrangement 19 is thus on the downstream side of the cylinder liners and cylinder heads that are cooled by the cooling liquid flowing in the high-temperature cooling circuit.
  • the flow restriction arrangement 19 is located upstream from the first by-pass valve 41.
  • FIG. 3 shows a flow restriction arrangement according to an embodiment of the invention.
  • the flow restriction arrangement 19 comprises a first duct portion 20.
  • the first duct portion 20 forms part of the cooling liquid duct of the high-temperature cooling circuit and has a first cross-sectional area in a plane that is perpendicular to the flow direction in first duct portion 20.
  • the first duct portion 20 has a circular shape with a first diameter.
  • the flow restriction arrangement 19 further comprises a second duct portion 21 , which also forms part of the cooling liquid duct.
  • the second duct portion 21 is located on the downstream side of the first duct portion 20.
  • the second duct portion 21 has a second cross-sectional area in a plane that is perpendicular to the flow direction in the second duct portion 21 .
  • the second duct portion 21 has a circular shape with a second diameter.
  • the second cross-sectional area is greater than the first cross-sectional area. The diameter of the cooling liquid duct in which the cooling liquid flows thus increases from the first diameter to the second diameter.
  • the flow restriction arrangement 19 further comprises a flow restrictor element 23 that is moveable in the axial direction of the first duct portion 20 and configured such that the flow area past the flow restrictor element 23 from the first duct portion 20 to the second duct portion 21 depends on the position of the flow restrictor element 23 in the axial direction of the first duct portion 20.
  • the flow area past the flow restrictor element 23 is formed between the inner surface of the cooling liquid duct and an outer surface of the flow restrictor element 23.
  • the flow restriction arrangement 19 is configured such that the flow area past the flow restrictor element 23 can be adjusted to be smaller than the first cross-sectional area.
  • the flow area past the flow restrictor element 23 and thus the pressure drop over the flow restrictor element 23 can be adjusted. This affects the flow rate in the high-temperature cooling circuit.
  • the flow restrictor element 23 is configured to be moveable without draining of the high-temperature cooling circuit. Nor is there a need to dismount any duct parts of the high-temperature cooling circuit. The flow in the high-temperature cooling circuit can thus be easily adjusted. The flow can be adjusted even when the engine 40 is running.
  • the flow restrictor element 23 is configured to be movable in a stepless manner. Also the adjustment of the flow area past the flow restrictor element 23 is thus stepless.
  • the flow restrictor element 23 comprises a flow control portion 24, of which position determines the flow area past the flow restrictor element 23, and a shaft 25 connected to the flow control portion 24 for moving the flow control portion 24.
  • the flow control portion 24 has a conical or frusto-conical shape having a tapered end facing the upstream side of the flow in the cooling circuit. The shape of the flow control portion 24 ensures smooth flow over the flow restrictor element 23 and reduces the risk of cavitation.
  • the flow restrictor element 23 has at least one position, where at least part of the flow control portion 24 extends to the area of the first duct portion 20 in the axial direction of the first duct portion 20.
  • the shaft 25 of the flow restrictor element 23 extends to the outside of the cooling liquid duct.
  • the flow restriction arrangement is provided with a sleeve 28, through which the shaft 25 extends.
  • the inner surface of the sleeve 28 is provided with a sealing groove and a seal 29 arranged in the sealing groove.
  • the cooling liquid duct is provided with a bend on the downstream side of the second duct portion 21 to allow keeping the length of the shaft 25 short.
  • the flow restrictor element 23 can be configured to be manually moveable, or the flow restriction arrangement 19 can be provided with an actuator for moving the flow restrictor element 23.
  • the flow restriction arrangement 19 comprises a transition portion 22 between the first duct portion 20 and the second duct portion 21 .
  • the cross-sectional area of the transition portion 22 increases gradually in the flow direction of the cooling liquid.
  • the diameter of the cooling liquid duct thus increases gradually from the first diameter to the second diameter.
  • the transition portion 22 is arranged immediately downstream from the first duct portion 20 and the second duct portion 21 is arranged immediately downstream from the transition portion 22.
  • the first duct portion 20, the transition portion 22 and the second duct portion 21 are arranged in a flow restriction block 26.
  • the flow restriction block 26 can be connected to a cooling medium pipe 27 of the cooling circuit.
  • the sleeve 28 is a separate part attached to the flow restriction block 26.
  • the sleeve 28 could also form an integral part of the flow restriction block.
  • the flow restriction block 26, sleeve 28 and flow restrictor element 23 form a flow restriction module.
  • Figure 2 shows the flow restriction module attached to an engine.
  • the flow restriction arrangement 19 is attached to a side of the engine block. In the vertical direction, the flow restriction arrangement 19 is arranged above the cooling liquid pump 1 .
  • the flow restrictor element 23 is moveable in a direction that is substantially parallel to the lateral direction of the engine 40.

Landscapes

  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Supercharger (AREA)

Abstract

The cooling system for an internal combustion engine (40) comprises a cooling circuit, in which cooling liquid can be circulated to cool down components of the engine (40) and/or fluids flowing in the engine (40), a pump (1) for pressurizing the cooling liquid, and a flow restriction arrangement for adjusting the flow of cooling liquid, the arrangement (19) comprising a first duct portion (20) forming part of said cooling circuit and having a first cross-sectional area, a second duct portion (21) located downstream from the first duct portion (20) and having a second cross-sectional area that is greater than the first cross-sectional area, and a flow restrictor element (23) that is moveable in the axial direction of the first duct portion (20) and configured such that flow area past the flow restrictor element (23) from the first duct portion (20) to the second duct portion (21) depends on the position of the flow restrictor element (23).

Description

Cooling system for an internal combustion engine and piston engine
Technical field of the invention
The invention concerns a cooling system for an internal combustion engine in accordance with claim 1 . The invention also concerns a piston engine.
Background of the invention
Large internal combustion engines, such as ship or power plant engines, are often provided with two separate cooling circuits, namely a high temperature (HT) circuit and a low temperature (LT) circuit. The HT circuit is used for controlling the temperature of the cylinder liners and the cylinder heads. The HT circuit can also connected to the high temperature part of a double-stage charge air cooler. The LT circuit typically serves at least the low-temperature part of the charge air cooler and a lube oil cooler. Temperature in the HT circuit is, depending on the engine type, typically around 70-102 °C and in the LT circuit 38-60 °C. A relatively high temperature in the HT circuit is desirable for ensuring safe ignition and combustion of low-quality heavy fuels also at low loads, for minimizing temperature fluctuations in the components of the cylinders and for preventing corrosion that can be caused by excessive cooling.
It is important to maintain an appropriate flow rate and pressure in the cooling circuits. The pumps used for pressurizing the cooling liquid are typically impeller pumps. In a cooling circuit with an impeller pump, the flow depends on the pressure drop in the cooling circuit.
For controlling the flow, the cooling circuit can be provided with one or more flow restrictors. The flow restrictors are typically orifice plates. The dimensions of the orifice determine the pressure drop over the orifice plate.
When a new engine is delivered, the cooling system is provided with orifice plates providing the desired flow characteristics. A problem of the orifice plates is that if adjustments are needed, the cooling circuit needs to be drained and part of the piping needs to be dismounted to replace one or more of the orifice plates by a different orifice plate, or to add or remove orifice plates. Summary of the invention
An object of the present invention is to provide an improved cooling system for an internal combustion engine. The characterizing features of the cooling system according to the invention are presented in claim 1 . Another object of the invention is to provide an improved piston engine, as defined in another claim.
The cooling system according to the invention comprises at least one cooling circuit, in which cooling circuit cooling liquid can be circulated to cool down components of the engine and/or fluids flowing in the engine, at least one pump for pressurizing the cooling liquid circulated in said cooling circuit, and a flow restriction arrangement for adjusting the flow of cooling liquid in said cooling circuit. The flow restriction arrangement comprises a first duct portion forming part of said cooling circuit and having a first cross-sectional area, a second duct portion located in said cooling circuit downstream from the first duct portion and having a second cross-sectional area that is greater than the first cross-sectional area, and a flow restrictor element that is moveable in the axial direction of the first duct portion and configured such that flow area past the flow restrictor element from the first duct portion to the second duct portion depends on the position of the flow restrictor element in the axial direction of the first duct portion.
In the cooling system according to the invention, the pressure drop over the flow restrictor element can be adjusted by moving the flow restrictor element. This allows adjusting the flow in the cooling circuit without draining the cooling circuit and dismounting any cooling liquid pipes. The flow could be adjusted even when the engine is running.
According to an embodiment of the invention, the flow restrictor element comprises a flow control portion, of which position determines the flow area past the flow restrictor element, and a shaft connected to the flow control portion for moving the flow control portion.
According to an embodiment of the invention, the flow control portion has a conical or frusto-conical shape having a tapered end facing the upstream side of the flow in the cooling circuit. Because of the shape of the flow control portion, the cooling liquid flows smoothly past the flow restrictor element and the risk of cavitation is reduced. According to an embodiment of the invention, the flow restriction arrangement comprises a transition portion between the first duct portion and the second duct portion, the cross-sectional area of the transition portion increasing gradually in the flow direction of the cooling liquid. The transition portion of the cooling liquid duct facilitates smooth flow from the first duct portion to the second duct portion.
According to an embodiment of the invention, at least the second duct portion is arranged in a flow restriction block that is connectable to a cooling medium pipe of the cooling circuit. The modular structure allows easy assembly of the flow restriction arrangement.
According to an embodiment of the invention, the flow restriction arrangement is arranged in the cooling circuit on the downstream side of the cylinder liners cooled by the cooling circuit.
According to an embodiment of the invention, the cooling circuit is a high-tem- perature cooling circuit of the engine.
The piston engine according to the invention comprises a cooling system defined above.
According to an embodiment of the invention, the flow restriction arrangement is attached to a side of the engine block.
Brief description of the drawings
Embodiments of the invention are described below in more detail with reference to the accompanying drawings, in which
Fig. 1 shows a cooling system according to an embodiment of the invention,
Fig. 2 shows an engine with a flow restriction arrangement according to an embodiment of the invention, and
Fig. 3 shows a cross-sectional view of the flow restriction arrangement taken along line A-A of figure 1 . Detailed
Figure imgf000006_0001
of embodiments of the invention
In figure 1 is shown schematically a cooling system of an internal combustion engine 40. The engine 40 is a large internal combustion engine, such as a main or an auxiliary engine of a ship or an engine that is used at a power plant for producing electricity. The cylinder bore of the engine 40 is at least 150 mm. Figure 1 shows an in-line engine, but the engine could also be a V-engine.
In the embodiment of figure 1 , the engine 40 is provided with two turbochargers 45, 46. A first turbocharger 45 is a low-pressure turbocharger and a second turbocharger 46 is a high-pressure turbocharger. The turbochargers 45, 46 are connected in series. The pressure of the intake air of the engine 40 is raised in the low-pressure turbocharger 45 from the ambient pressure to a first pressure level and then in the high-pressure turbocharger 46 from the first pressure level to a second pressure level, which is higher than the first pressure level.
The intake air of the engine 40 could be pressurized also by a single turbocharger. A V-engine could be provided with separate turbochargers for each bank of the engine. A V-engine could thus be provided with two turbochargers arranged in parallel, or two low-pressure turbocharger arranged in parallel and two high-pressure turbochargers arranged in parallel.
The intake air of the engine 40 is cooled down between the low-pressure turbocharger 45 and the high-pressure turbocharger 46 and after the high-pressure turbocharger 46. A low-pressure charge air cooler is arranged between the low-pressure turbocharger 45 and the high-pressure turbocharger 46. The low-pressure charge air cooler comprises a first stage 47 and a second stage 48. A high-pressure charge air cooler is arranged after the high-pressure turbocharger 46. The high-pressure charge air cooler comprises a first stage 49 and a second stage 50. The intake air is thus cooled down in two stages both between the turbochargers 45, 46 and downstream from the high-pressure turbocharger 46. The two stages of the charge air coolers could also be separate charge air coolers. The cooling system could also be provided with single stage cooling between the turbochargers 45, 46 and/or between the high-pressure turbocharger 46 and the engine 40.
The cooling system of the engine 40 comprises a high -temperature cooling circuit and a low-temperature cooling circuit. In the low-temperature cooling circuit, the temperature of the cooling liquid is lower than in the high-temperature cooling circuit. Temperature in the high -temperature cooling circuit is typically around 70-105 °C and in the low-temperature cooling circuit 35-55 °C. The cooling liquid in the cooling circuits can be, for instance, water. The cooling liquid can also contain additives, for example for preventing corrosion.
The cooling system comprises a cooling liquid pump 1 for circulating the cooling liquid in the cooling system. The cooling liquid pump 1 can be, for instance, an impeller pump. In the embodiment of figure 1 , the cooling system comprises a single cooling liquid pump 1. The cooling liquid pump 1 comprises a high- temperature portion 2 for pressurizing the cooling liquid circulated in the high- temperature cooling circuit and a low-temperature portion 3 for pressurizing the cooling liquid circulated in the low-temperature cooling circuit. The cooling liquid pump 1 is provided with a common shaft 10 for driving both the high- temperature portion 2 and the low-temperature portion 3. The cooling liquid pump 1 is mechanically coupled to the engine 40 to be driven by the engine. Instead of a single cooling liquid pump 1 circulating cooling liquid both in the low-temperature cooling circuit and the high-temperature cooling circuit, the cooling system could be provided with separate low-temperature and high- temperature pumps.
The cooling liquid pump 1 comprises a first inlet 13, a second inlet 14 and a third inlet 17. The first 13 and the second inlet 14 are inlets of the high-temper- ature portion 2 and the third inlet 17 is an inlet of the low-temperature portion 3. The cooling liquid pump 1 further comprises a first outlet 16, which is an outlet of the high-temperature portion 2, and a second outlet 18, which is an outlet of the low-temperature portion 3.
The high-temperature cooling circuit is arranged to cool down at least the cylinder liners and the cylinder heads of the engine 40. In the high-temperature cooling circuit, the cooling liquid flows from the high-temperature portion 2 of the cooling liquid pump 1 to the engine 40, where heat is transferred from the cylinder liners and the cylinder heads of the engine 40 to the cooling liquid. A check valve 51 is arranged on the downstream side of the high-temperature portion 2 of the cooling liquid pump 1 to prevent backflow to the cooling liquid pump 1 . From the engine 40, the cooling liquid flows to a first by-pass valve 41. The first by-pass valve 41 allows conducting the cooling liquid selectively either to the second inlet 14 of the high-temperature portion 2 of the cooling liquid pump 1 or to a first heat exchanger 42. The first heat exchanger 42 is configured to cool down the cooling liquid received from the high-temperature cooling circuit. From the first heat exchanger 42, the cooled down cooling liquid is conducted to the second inlet 17 of the cooling liquid pump 1 , i.e. the inlet 17 of the low- temperature portion 3. The first by-pass valve 41 can be used for controlling the temperature of the cooling liquid in the high-temperature cooling circuit. If the temperature is too low, hot cooling liquid can be conducted from the end of the high-temperature cooling circuit to the second inlet of the high-temperature portion 2 of the cooling liquid pump 1 to increase the temperature in the high-temperature cooling circuit. If the temperature is too high, the cooling liquid from the high-temperature cooling circuit can be conducted to the first heat exchanger 42.
The cooling system further comprises a second by-pass valve 43. The second by-pass valve 43 allows by-passing the first heat exchanger 42 to conduct cooling liquid from the high-temperature cooling circuit to the inlet 17 of the low-temperature portion 3 of the cooling liquid pump 1 .
From the low-temperature portion 3 of the cooling liquid pump 1 , the cooling liquid is conducted to a second heat exchanger 44, where the cooling liquid is heated. A check valve 52 is arranged between the low-temperature portion 3 of the cooling liquid pump 1 and the second heat exchanger 44 to prevent backflow to the cooling liquid pump 1. From the second heat exchanger 44, the cooling liquid is conducted to the second stage 48 of the low-pressure charge air cooler, where heat is transferred from the intake air of the engine 40 to the cooling liquid. From the second stage 48 of the low-pressure charge air cooler 48, the cooling liquid is conducted to the second stage 50 of the high- pressure charge air cooler, where heat is transferred from the intake air to the cooling liquid. From the second stage 50 of the high-pressure charge air cooler, the cooling liquid is conducted to the first stage 49 of the high-pressure charge air cooler. In the first stage 49 of the high-pressure charge air cooler, further heat is transferred from the intake air to the cooling liquid. From the first stage 49 of the high-pressure charge air cooler, the cooling liquid is conducted to the first stage 47 of the low-pressure charge air cooler. Although the cooling liquid has been heated in the other cooling stages, the temperature of the cooling liquid is still lower than the temperature of the intake air after the low-pressure turbocharger 45, and heat is transferred from the intake air to the cooling liquid.
After the first stage 47 of the low-pressure charge air cooler, the temperature of the cooling liquid in the low-temperature cooling circuit is at its highest. The cooling liquid is conducted to the first inlet 13 of the high-temperature portion 2 of the cooling liquid pump 1. In the cooling liquid pump 1 , the cooling liquid is mixed with cooling liquid that is introduced into the high-temperature portion 2 through the second inlet 14.
Part of the cooling liquid from the low-temperature cooling circuit can flow to the first heat exchanger 42, where it is cooled down before being conducted through the second by-pass valve 43 to the inlet 17 of the low-temperature portion 3 of the cooling liquid pump 1 .
The low-temperature cooling circuit can be arranged to cool down also the lube oil of the engine. A lube oil cooler could be arranged in the low-temperature cooling circuit, for instance, between the first stage 49 of the high-pressure charge air cooler and the first stage 47 of the low-pressure charge air cooler.
Depending on the engine 40, the cooling system could be configured also in many alternative ways. For instance, the first stage 47 of the low-pressure charge air cooler could be arranged in the high-temperature cooling circuit. The cooling circuits could also comprise by-pass ducts for one or more stages 47, 48, 49, 50 of the charge air coolers.
Figure 1 shows a simplified illustration of a cooling system, and the cooling system can comprise many additional components. For instance, the cooling system can comprise a low-temperature stand-by pump and a high-temperature stand-by pump. The stand-by pumps can be driven for circulating cooling liquid in the cooling system when the engine 40 is not running.
The flow of the cooling liquid in the high-temperature cooling circuit and/or the low-temperature cooling circuit can be adjusted by providing the cooling circuit with a flow restrictor causing a pressure drop. The flow of the cooling liquid may need to be adjusted, for example, if the engine or cooling system configuration is changed. For instance, if a turbocharger of the engine is replaced by a different turbocharger or heat exchangers are changed, there may be a need to adjust the flow. Also, a change in the operating conditions may necessitate adjustment of the cooling liquid flow.
For adjusting the flow of cooling liquid in the high-temperature cooling circuit, the cooling system is provided with a flow restriction arrangement 19. The flow restriction arrangement 19 is arranged in the high-temperature cooling circuit downstream from the engine 40. The flow restriction arrangement 19 is thus on the downstream side of the cylinder liners and cylinder heads that are cooled by the cooling liquid flowing in the high-temperature cooling circuit. The flow restriction arrangement 19 is located upstream from the first by-pass valve 41.
Figure 3 shows a flow restriction arrangement according to an embodiment of the invention. The flow restriction arrangement 19 comprises a first duct portion 20. The first duct portion 20 forms part of the cooling liquid duct of the high-temperature cooling circuit and has a first cross-sectional area in a plane that is perpendicular to the flow direction in first duct portion 20. The first duct portion 20 has a circular shape with a first diameter.
The flow restriction arrangement 19 further comprises a second duct portion 21 , which also forms part of the cooling liquid duct. The second duct portion 21 is located on the downstream side of the first duct portion 20. The second duct portion 21 has a second cross-sectional area in a plane that is perpendicular to the flow direction in the second duct portion 21 . The second duct portion 21 has a circular shape with a second diameter. The second cross-sectional area is greater than the first cross-sectional area. The diameter of the cooling liquid duct in which the cooling liquid flows thus increases from the first diameter to the second diameter.
The flow restriction arrangement 19 further comprises a flow restrictor element 23 that is moveable in the axial direction of the first duct portion 20 and configured such that the flow area past the flow restrictor element 23 from the first duct portion 20 to the second duct portion 21 depends on the position of the flow restrictor element 23 in the axial direction of the first duct portion 20. The flow area past the flow restrictor element 23 is formed between the inner surface of the cooling liquid duct and an outer surface of the flow restrictor element 23. The flow restriction arrangement 19 is configured such that the flow area past the flow restrictor element 23 can be adjusted to be smaller than the first cross-sectional area.
By adjusting the position of the flow restrictor element 23, the flow area past the flow restrictor element 23 and thus the pressure drop over the flow restrictor element 23 can be adjusted. This affects the flow rate in the high-temperature cooling circuit. The flow restrictor element 23 is configured to be moveable without draining of the high-temperature cooling circuit. Nor is there a need to dismount any duct parts of the high-temperature cooling circuit. The flow in the high-temperature cooling circuit can thus be easily adjusted. The flow can be adjusted even when the engine 40 is running. Preferably, the flow restrictor element 23 is configured to be movable in a stepless manner. Also the adjustment of the flow area past the flow restrictor element 23 is thus stepless.
In the embodiment of the figures, the flow restrictor element 23 comprises a flow control portion 24, of which position determines the flow area past the flow restrictor element 23, and a shaft 25 connected to the flow control portion 24 for moving the flow control portion 24. The flow control portion 24 has a conical or frusto-conical shape having a tapered end facing the upstream side of the flow in the cooling circuit. The shape of the flow control portion 24 ensures smooth flow over the flow restrictor element 23 and reduces the risk of cavitation. The flow restrictor element 23 has at least one position, where at least part of the flow control portion 24 extends to the area of the first duct portion 20 in the axial direction of the first duct portion 20.
The shaft 25 of the flow restrictor element 23 extends to the outside of the cooling liquid duct. The flow restriction arrangement is provided with a sleeve 28, through which the shaft 25 extends. The inner surface of the sleeve 28 is provided with a sealing groove and a seal 29 arranged in the sealing groove. The cooling liquid duct is provided with a bend on the downstream side of the second duct portion 21 to allow keeping the length of the shaft 25 short.
The flow restrictor element 23 can be configured to be manually moveable, or the flow restriction arrangement 19 can be provided with an actuator for moving the flow restrictor element 23.
In the embodiment of the figures, the flow restriction arrangement 19 comprises a transition portion 22 between the first duct portion 20 and the second duct portion 21 . The cross-sectional area of the transition portion 22 increases gradually in the flow direction of the cooling liquid. The diameter of the cooling liquid duct thus increases gradually from the first diameter to the second diameter. The transition portion 22 is arranged immediately downstream from the first duct portion 20 and the second duct portion 21 is arranged immediately downstream from the transition portion 22.
In the embodiment of the figures, the first duct portion 20, the transition portion 22 and the second duct portion 21 are arranged in a flow restriction block 26. The flow restriction block 26 can be connected to a cooling medium pipe 27 of the cooling circuit. In the embodiment of the figures, the sleeve 28 is a separate part attached to the flow restriction block 26. However, the sleeve 28 could also form an integral part of the flow restriction block. The flow restriction block 26, sleeve 28 and flow restrictor element 23 form a flow restriction module. Figure 2 shows the flow restriction module attached to an engine. In the embodiment of figure 2, the flow restriction arrangement 19 is attached to a side of the engine block. In the vertical direction, the flow restriction arrangement 19 is arranged above the cooling liquid pump 1 . The flow restrictor element 23 is moveable in a direction that is substantially parallel to the lateral direction of the engine 40.
It will be appreciated by a person skilled in the art that the invention is not limited to the embodiments described above, but may vary within the scope of the appended claims.

Claims

Claims:
1. A cooling system for an internal combustion engine (40), the cooling system comprising at least one cooling circuit, in which cooling circuit cooling liquid can be circulated to cool down components of the engine (40) and/or fluids flowing in the engine (40), and at least one pump (1 ) for pressurizing the cooling liquid circulated in said cooling circuit, the cooling system comprising a flow restriction arrangement (19) for adjusting the flow of cooling liquid in said cooling circuit, wherein the flow restriction arrangement (19) comprises
- a first duct portion (20) forming part of said cooling circuit and having a first cross-sectional area,
- a second duct portion (21 ) located in said cooling circuit downstream from the first duct portion (20) and having a second cross-sectional area that is greater than the first cross-sectional area, and
- a flow restrictor element (23) that is moveable in the axial direction of the first duct portion (20) and configured such that flow area past the flow restrictor element (23) from the first duct portion (20) to the second duct portion (21 ) depends on the position of the flow restrictor element (23) in the axial direction of the first duct portion (20).
2. A cooling system according to claim 1 , wherein the flow restrictor element (23) comprises a flow control portion (24), of which position determines the flow area past the flow restrictor element (23), and a shaft (25) connected to the flow control portion (24) for moving the flow control portion (24).
3. A cooling system according to claim 2, wherein the flow control portion (24) has a conical or frusto-conical shape having a tapered end facing the upstream side of the flow in the cooling circuit.
4. A cooling system according to any of claims 1-3, wherein the flow restriction arrangement (19) comprises a transition portion (22) between the first duct portion (20) and the second duct portion (21 ), the cross-sectional area of the transition portion (22) increasing gradually in the flow direction of the cooling liquid.
5. A cooling system according to any of the preceding claims, wherein at least the second duct portion (21 ) is arranged in a flow restriction block (26) that is connectable to a cooling medium pipe (27) of the cooling circuit.
6. A cooling system according to any of the preceding claims, wherein the flow restriction arrangement (19) is arranged in the cooling circuit on the downstream side of the cylinder liners cooled by the cooling circuit.
7. A cooling system according to any of the preceding claims, wherein the cooling circuit is a high-temperature cooling circuit of the engine (40).
8. A piston engine (40) comprising a cooling system according to any of the preceding claims.
9. A piston engine (40) according to claim 8, wherein the flow restriction arrangement (19) is attached to a side of the engine block.
PCT/FI2022/050577 2022-09-02 2022-09-02 Cooling system for an internal combustion engine and piston engine WO2024047274A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
PCT/FI2022/050577 WO2024047274A1 (en) 2022-09-02 2022-09-02 Cooling system for an internal combustion engine and piston engine

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/FI2022/050577 WO2024047274A1 (en) 2022-09-02 2022-09-02 Cooling system for an internal combustion engine and piston engine

Publications (1)

Publication Number Publication Date
WO2024047274A1 true WO2024047274A1 (en) 2024-03-07

Family

ID=83283454

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/FI2022/050577 WO2024047274A1 (en) 2022-09-02 2022-09-02 Cooling system for an internal combustion engine and piston engine

Country Status (1)

Country Link
WO (1) WO2024047274A1 (en)

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5038724A (en) * 1990-04-16 1991-08-13 Outboard Marine Corporation Debris resistant valve assembly
US20080017353A1 (en) * 2006-07-17 2008-01-24 Behr Gmbh & Co. Kg Valve for controlling a coolant flow for a heating element of a motor vehicle and system with at least one valve
FR2913374A1 (en) * 2007-03-08 2008-09-12 Itw Bailly Comte Soc Par Actio COOLING CIRCUIT FOR A MOTOR VEHICLE, DEGASSING TANK AND MOTOR VEHICLE THEREFOR

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5038724A (en) * 1990-04-16 1991-08-13 Outboard Marine Corporation Debris resistant valve assembly
US20080017353A1 (en) * 2006-07-17 2008-01-24 Behr Gmbh & Co. Kg Valve for controlling a coolant flow for a heating element of a motor vehicle and system with at least one valve
FR2913374A1 (en) * 2007-03-08 2008-09-12 Itw Bailly Comte Soc Par Actio COOLING CIRCUIT FOR A MOTOR VEHICLE, DEGASSING TANK AND MOTOR VEHICLE THEREFOR

Similar Documents

Publication Publication Date Title
US6098576A (en) Enhanced split cooling system
RU2589556C2 (en) Engine system and method of reducing production cost thereof
US7509793B2 (en) Fluid system
US10501169B2 (en) Propeller blade angle control system
US8601986B2 (en) Split cooling method and apparatus
US9739198B2 (en) Oil and fuel circuits in a turbine engine
US8943842B2 (en) Hybrid pumper
EP1329617A2 (en) Fluid flow system for a gas turbine engine
FR3110937B1 (en) Installation for supplying cryogenic fuel to the combustion chamber of a turbomachine.
EP1472444A1 (en) Sequential turbocharging system and a method for sequential turbocharging of an internal combustion engine
WO2024047274A1 (en) Cooling system for an internal combustion engine and piston engine
KR101946683B1 (en) Cooling system and method for an internal combustion engine
KR101671680B1 (en) Method for operating an internal combustion engine
US11591964B2 (en) Oil cooling system for aircraft engine
CN88100453A (en) Circulating cooling system
WO2012035202A1 (en) Cooling system for internal combustion engine
JP2002122021A (en) Turbo supercharge type engine cooling system with two- pass radiator
CN110185527A (en) Cooling Water of Diesel Locomotive system
CN109882293A (en) The hydraulic and Pneumatic control circuit with fuel/air mixture heat exchanger of turbojet
US12116923B2 (en) Conductor element for a fluid-cooled component of an internal combustion engine
CN219317013U (en) Cooling system for steam turbine generator unit and steam turbine generator unit system
CN220849848U (en) Comprehensive heat exchange device of engine
CN109154217A (en) oil supply system
WO2018050410A1 (en) Waste heat recovery system
WO2024047275A1 (en) Bearing housing for a cooling liquid pump, cooling liquid pump and cooling system

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 22769313

Country of ref document: EP

Kind code of ref document: A1