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
  • F01P3/00—Liquid cooling
  • F01P3/20—Cooling circuits not specific to a single part of engine or machine
  • F01P3/207—Cooling circuits not specific to a single part of engine or machine liquid-to-liquid heat-exchanging relative to marine vessels
• • 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
  • F01P7/16—Controlling of coolant flow the coolant being liquid by thermostatic control
  • F01P7/165—Controlling of coolant flow the coolant being liquid by thermostatic control characterised by systems with two or more loops
• • 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
  • F01P2050/00—Applications
  • F01P2050/02—Marine engines
  • F01P2050/06—Marine engines using liquid-to-liquid heat exchangers
• • 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
  • F01P2060/00—Cooling circuits using auxiliaries
  • F01P2060/02—Intercooler
• • 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
  • F01P2060/00—Cooling circuits using auxiliaries
  • F01P2060/04—Lubricant cooler

Definitions

• the present invention relates to a cooling system for an internal combustion engine in accordance with the preamble of claim 1 .
• the invention also con- cerns a method for cooling the cooling medium of a high temperature cooling circuit of an internal combustion engine according to the preamble of the other independent claim.
• a high temperature (HT) circuit is used for controlling the temperature of the cylinder liners and the cylinder heads.
• the HT circuit is also connected to the high temperature part of a double-stage charge air cooler.
• the LT circuit serves 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 ⁇ and in the LT circuit 38-50 ⁇ .
• 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.
• 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 given in the characterizing part of claim 1 .
• Another object of the invention is to provide an improved method for reducing the temperature of the cooling medium of a high temperature cooling circuit of an internal combustion engine.
• the characterizing features of the method are given in the characterizing part of the other independent claim.
• the cooling system comprises a high temperature cooling circuit and a low temperature cooling circuit.
• the cooling system is provided with a heat exchanger for transferring heat from the high temperature cooling circuit to the low temperature cooling circuit.
• the cooling medium of a high temperature cooling circuit is conducted through a heat exchanger, in which heat exchanger heat is transferred from the cooling medium of the high temperature cooling circuit to the cooling medium of a low temperature cooling circuit.
• the temperature of the cooling medium in the high temperature cooling circuit can be kept within desired temperature limits without modifications of the external components of the cooling system.
• the cooling system can be easily applied to existing engines, which are upgraded with more effective turbocharging systems.
• both the cooling medium of the high temperature cooling circuit and the cooling medium of the low temperature cooling circuit can be arranged to flow through the heat exchanger.
• the heat exchanger is arranged in the low temperature cooling circuit and the high-temperature cooling circuit is provided with means for selectively conducting the cooling medium through the heat exchanger.
• the means for selectively conducting the cooling medium through the heat exchanger can comprise a selector valve, which allows bypassing of the heat exchanger.
• Fig. 1 shows schematically a cooling system of an internal combustion engine.
• FIG 1 is shown schematically a cooling system of an internal combustion engine 1 .
• the engine 1 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 cooling system of the engine 1 comprises two separate cooling circuits 2, 3. Both cooling circuits 2, 3 are closed circuits.
• One of the cooling circuits 2, 3 is a high temperature cooling circuit 2 and the other one is a low temperature cooling circuit 3, in which the temperature of the cooling medium is lower than in the high temperature cooling circuit 2.
• Temperature in the high temperature cooling circuit 2 is typically around 70-105 ⁇ and in the low temperature cooling circuit 35-55 ⁇ .
• Th e cooling medium in the cooling circuits 2, 3 can be, for instance, water.
• the cooling medium can also contain additives, for example for preventing corrosion.
• Each cooling medium circuit 2, 3 is provided with a pump 8, 9 for circulating the cooling medium.
• the cooling system is further provided with an external cooling circuit 13, where heat is transferred from the high temperature and the low temperature cooling circuits 2, 3 to the external cooling circuit 13.
• the external cooling circuit 13 is provided with a pump 12 for circulating the cooling medium in the circuit 13.
• the external cooling circuit 13 also comprises a low temperature heat exchanger 15 for transferring heat from the low temperature cooling circuit 3 to the external cooling circuit 13 and with a high temperature heat exchanger 16 for transferring heat from the high temperature cooling circuit 2 to the external cooling circuit 13.
• the high temperature heat exchanger 16 is arranged in the flow direction of the cooling medium of the external cooling circuit 13 after the low temperature heat exchanger 15.
• the external cooling circuit 13 may be either an open or a closed circuit.
• the external cooling circuit 13 may comprise one or more additional heat exchangers for transferring heat away from the cooling medium of the external cooling circuit 13.
• the cooling medium flows from the pump 8 to the engine 1 , where heat is transferred from the cylinder liners and the cylinder heads of the engine 1 to the cooling medium.
• the cooling medium of the high temperature cooling circuit 2 flows to a first charge air cooler 7.
• the first charge air cooler 7 is connected to a compressor 1 1 of a turbocharger 17. In the first charge air cooler 7, heat is transferred from the charge air to the cooling medium of the high temperature cooling circuit 2. If the engine 1 is provided with two-stage turbocharging, the first charge air cooler 7 could also be arranged between the two stages.
• the pressure in the high-temperature cooling circuit 2 is typically around 2.5 bar after the first charge air cooler 7.
• the cooling medium flows to the high temperature heat exchanger 16, where heat is transferred from the cooling medium of the high temperature cooling circuit 2 to the cooling medium of the external cooling circuit 13.
• the cooling medium of the high temperature cooling circuit 2 then returns to the pump 8 at a lower temperature.
• the pressure of the cooling medium is typically around 1 .5 bar at this stage.
• the cooling medium flows from the pump 9 to a second charge air cooler 10.
• the second charge air cooler 10 is arranged downstream from the first charge air cooler 7 in the flow direction of the charge air.
• heat is transferred from the charge air to the cooling medium of the low temperature cooling circuit 3.
• the pressure in the low-temperature cooling circuit 3 is typically around 2.5 bar after the second charge air cooler 10.
• From the second charge air cooler 10, the charge air is conducted into the intake manifold of the engine 1 .
• the cooling medium is conducted from the second charge air cooler 10 to a lube oil cooler 14, where heat is transferred from the lube oil of the engine 1 to the cooling medium of the low temperature cooling circuit 3.
• the low temperature cooling circuit 3 is also provided with a bypass valve 17 and a bypass duct 18.
• the bypass duct 18 is arranged parallel with the second charge air cooler 10.
• the bypass valve 17 can be used for allowing flow through the bypass duct 18 and thus bypassing of the second charge air cooler 10, when higher charge air temperature is needed.
• the cooling system is provided with a heat exchanger 4 for transferring heat from the cooling medium of the high temperature cooling circuit 2 to the cooling medium of the low temperature cooling circuit 3. Cooling medium of both the high temperature cooling circuit 2 and the low temperature cooling circuit 3 can be arranged to flow through the heat exchanger 4.
• the heat exchanger 4 is thus a liquid-liquid heat exchanger.
• the heat exchanger 4 is arranged in the low temperature cooling circuit 3, and the cooling medium of the high temperature cooling circuit 2 can be selectively conducted through the heat exchanger 4.
• the heat exchanger 4 is located in the low temperature cooling circuit 3 downstream from the lube oil cooler 14 and upstream from the low temperature heat exchanger 15.
• the high temperature cooling circuit 2 comprises means 5, 6 for selectively conducting cooling medium through the heat exchanger 4.
• the means 5, 6 comprise a selector valve 5 and a cooling duct 6 for conducting the cooling medium through the heat exchanger 4.
• the cooling duct 6 is connected to the selector valve 5 and to a point of the high temperature cooling circuit 2 downstream from the selector valve 5. Because of the selector valve 5, the heat exchanger 4 can be bypassed when there is no risk of excessive heating of the cooling medium of the high temperature cooling circuit 2.
• the selector valve 5 can be an automat- ic temperature controlled valve, which conducts the cooling medium to the heat exchanger 4 when the temperature of the cooling medium in the high temperature cooling circuit 2 exceeds a predetermined limit value.
• the temperature of the cooling medium in the high temperature cooling circuit 2 can be kept within the desired limits.
• the system is particularly beneficial when an existing engine 1 is upgraded with more effective turbochargers 7. Only minor changes are needed for upgrading the existing cooling system.
• the flow rates and duct sizes in the cooling circuits 2, 3, 13 do not have to be changed.
• the heat exchanger can be arranged in the high temperature cooling circuit and the cooling medium of the low temperature cooling circuit can be selectively arranged to flow through the heat exchanger.
• the cooling circuits can be arranged to cool also other objects than those shown in the embodiments.
• the objects to be cooled can also be ar- ranged in a different order.

Landscapes

• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Mechanical Engineering (AREA)
• General Engineering & Computer Science (AREA)
• Ocean & Marine Engineering (AREA)
• Supercharger (AREA)
• Cooling, Air Intake And Gas Exhaust, And Fuel Tank Arrangements In Propulsion Units (AREA)

Priority Applications (4)

Applications Claiming Priority (1)

Publications (1)

Family

ID=47563529

Family Applications (1)

Country Status (4)

Cited By (1)

Families Citing this family (3)

Citations (5)

Family Cites Families (4)

• 2012
  • 2012-12-10 EP EP12816315.1A patent/EP2929159B1/en active Active
  • 2012-12-10 KR KR1020157018189A patent/KR101946683B1/ko active IP Right Grant
  • 2012-12-10 WO PCT/FI2012/051222 patent/WO2014091056A1/en active Application Filing
  • 2012-12-10 CN CN201280077040.5A patent/CN104797793A/zh active Pending

Patent Citations (5)

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