Water cooling system for internal combustion engine, internal combustion engine, and method for modifying water cooling system for internal combustion engine

Abstract

This water cooling system for an internal combustion engine comprises: a first circulation line through which first cooling water circulates; a cooler that cools components of the internal combustion engine with the first cooling water; a first heat exchanger that exchanges heat between a compressed gas guided to the internal combustion engine and the first cooling water; a second circulation line through which second cooling water having a lower temperature than the first cooling water circulates; and a second heat exchanger that exchanges heat between the compressed gas that has passed through the first heat exchanger and the second cooling water. The first circulation line includes a component cooling line provided with the cooler, and a compressed gas cooling line provided in parallel with the component cooling line. The first heat exchanger exchanges heat between the compressed gas and the first cooling water flowing through the compressed gas cooling line.

Description

Water cooling system for internal combustion engine, internal combustion engine, and method for retrofitting water cooling system of internal combustion engine

[0001] The present disclosure relates to a water cooling system for an internal combustion engine, an internal combustion engine including the water cooling system, and a method for retrofitting the water cooling system of the internal combustion engine. This application claims priority based on Japanese Patent Application No. 2024-203993 filed with the Japan Patent Office on November 22, 2024, the content of which is incorporated herein by reference.

[0002] Some water cooling systems for internal combustion engines include a cooler (engine jacket, oil cooler) for cooling the components of the internal combustion engine with cooling water, and a heat exchanger (air cooler) for cooling the compressed gas introduced into the internal combustion engine. Patent Document 1 discloses cooling an engine jacket or the like with high-temperature side cooling water cooled by a high-temperature side radiator, and cooling an air cooler or the like with low-temperature side cooling water cooled by a low-temperature side radiator.

[0003] Japanese Patent Application Laid-Open No. 2005-299472

[0004] In the above-described water cooling system for an internal combustion engine, if the flow rate of the cooling water decreases due to an increase in the pressure loss of the cooling water system through which the cooling water flows, there is a risk that the cooling performance of the cooler for cooling the components of the internal combustion engine and the heat exchanger for cooling the compressed gas introduced into the internal combustion engine cannot be fully exhibited.

[0005] In view of the above circumstances, at least one embodiment of the present disclosure aims to provide a water cooling system for an internal combustion engine that can fully exhibit the cooling performance of a cooler for cooling the components of the internal combustion engine and a heat exchanger for cooling the compressed gas introduced into the internal combustion engine.

[0006] A water cooling system for an internal combustion engine according to at least one embodiment of the present disclosure is a water cooling system for an internal combustion engine for cooling components of the internal combustion engine and compressed gas directed to the internal combustion engine, comprising: a first circulation line configured to circulate first coolant cooled by a first radiator; a cooler configured to cool the components of the internal combustion engine with the first coolant flowing through the first circulation line; a first heat exchanger configured to perform heat exchange between the compressed gas compressed by a compressor and directed to the internal combustion engine and the first coolant flowing through the first circulation line; a second circulation line configured to circulate second coolant cooled by a second radiator at a lower temperature than the first coolant; and a second heat exchanger configured to perform heat exchange between the compressed gas that has passed through the first heat exchanger and the second coolant flowing through the second circulation line, wherein the first circulation line includes a components cooling line on which the cooler is provided and a compressed gas cooling line provided in parallel with the components cooling line. A water cooling system for an internal combustion engine, wherein the first heat exchanger is configured to perform heat exchange between the compressed gas and the first cooling water flowing through the compressed gas cooling line.

[0007] An internal combustion engine system according to at least one embodiment of the present disclosure comprises: a water cooling system for the internal combustion engine; the internal combustion engine; and the compressor.

[0008] A method for modifying a water-cooling system for an internal combustion engine according to at least one embodiment of the present disclosure is a method for modifying a water-cooling system for an internal combustion engine for cooling components of the internal combustion engine and compressed gas directed to the internal combustion engine, wherein the water-cooling system for the internal combustion engine comprises: a first circulation line configured to circulate first coolant cooled by a first radiator; a cooler configured to cool the components of the internal combustion engine with the first coolant flowing through the first circulation line; a first heat exchanger configured to perform heat exchange between the compressed gas compressed by a compressor and directed to the internal combustion engine and the first coolant flowing through the first circulation line; a second circulation line configured to circulate second coolant cooled by a second radiator at a lower temperature than the first coolant; and a second heat exchanger configured to perform heat exchange between the compressed gas that has passed through the first heat exchanger and the second coolant flowing through the second circulation line, and the method for modifying the water-cooling system for the internal combustion engine is: The method includes a compressed gas cooling line addition step of adding a compressed gas cooling line in parallel with the component cooling line in which the cooler of the first circulation line is provided, and a first heat exchanger relocation step of moving the first heat exchanger, which is provided in series with respect to the cooler in the component cooling line, from the component cooling line to the compressed gas cooling line.

[0009] According to at least one embodiment of the present disclosure, a water cooling system for an internal combustion engine is provided that can fully utilize the cooling performance of a cooler for cooling the components of the internal combustion engine and a heat exchanger for cooling the compressed gas introduced into the internal combustion engine.

[0010] This is a schematic diagram illustrating the configuration of an internal combustion engine system equipped with a water cooling system for an internal combustion engine according to one embodiment of the present disclosure. This is a schematic diagram illustrating the configuration of an internal combustion engine system equipped with a water cooling system for an internal combustion engine according to a comparative example. This is an explanatory diagram for illustrating an orifice in the water cooling system for an internal combustion engine according to one embodiment of the present disclosure. This is an explanatory diagram illustrating modified examples of the first component cooling line and the second component cooling line. This is an explanatory diagram illustrating modified examples of the first component cooling line and the second component cooling line.

[0011] Hereinafter, several embodiments of this disclosure will be described with reference to the attached drawings. However, the dimensions, materials, shapes, relative arrangements, etc., of the components described or shown in the drawings as embodiments are not intended to limit the scope of this disclosure, but are merely illustrative examples.

[0012] (Water Cooling System for Internal Combustion Engine) Figure 1 is a schematic diagram showing the configuration of an internal combustion engine system 10 comprising a water cooling system 1 for an internal combustion engine 2 according to one embodiment of the present disclosure. The water cooling system 1 for the internal combustion engine 2 is for cooling the components 3 of the internal combustion engine 2 and the compressed gas introduced into the internal combustion engine 2. As shown in Figure 1, the water cooling system 1 for the internal combustion engine 2 comprises a first circulation line 4, a second circulation line 5, a cooler 6, a first heat exchanger 7, and a second heat exchanger 8.

[0013] (First Circulation Line) As shown in Figure 1, the first circulation line 4 is configured to circulate the first coolant cooled by the first radiator 41. The first circulation line 4 is a flow path for circulating the first coolant. The first circulation line 4 is provided with the first radiator 41 and the first pump 42 for supplying the first coolant in the first circulation line 4. Hereinafter, the flow direction of the first coolant in the first circulation line 4 starts from the first coolant outlet 411 of the first radiator 41 (upstream end). The first coolant flows through the first circulation line 4 downstream in the flow direction of the first coolant by driving the first pump 42.

[0014] The water cooling system 1 includes a first cooling device 40 for cooling the first coolant. The first cooling device 40 consists of a first radiator 41 and a first fan 43 for air-cooling the first radiator 41. The first cooling device 40 is configured to exchange heat between the air supplied to the vicinity of the first radiator 41 by the first fan 43 and the first coolant inside the first radiator 41. The first coolant inside the first radiator 41 is air-cooled by the air surrounding the first radiator 41.

[0015] (Second Circulation Line) As shown in Figure 1, the second circulation line 5 is configured to circulate the second coolant cooled by the second radiator 51. The second coolant flowing through the second circulation line 5 is at a lower temperature than the first coolant flowing through the first circulation line 4. The second circulation line 5 is a flow path for circulating the second coolant. The second circulation line 5 is provided with the second radiator 51 and the second pump 52 for supplying the second coolant in the second circulation line 5. Hereinafter, the flow direction of the second coolant in the second circulation line 5 starts from the second coolant outlet 511 of the second radiator 51 (upstream end). The second coolant flows through the second circulation line 5 downstream in the direction of the second coolant flow by driving the second pump 52.

[0016] The water cooling system 1 includes a second cooling device 50 for cooling the second coolant. The second cooling device 50 consists of a second radiator 51 and a second fan 53 for air-cooling the second radiator 51. The second cooling device 50 is configured to exchange heat between the air supplied to the vicinity of the second radiator 51 by the second fan 53 and the second coolant inside the second radiator 51. The second coolant inside the second radiator 51 is air-cooled by the air surrounding the second radiator 51.

[0017] (Cooler) The cooler 6 is configured to cool the components 3 of the internal combustion engine 2 with first cooling water flowing through the first circulation line 4. The first circulation line 4 includes a components cooling line 44 in which the cooler 6 is installed. The cooler 6 is configured to exchange heat between the first cooling water flowing through the components cooling line 44 and the components 3. The components 3 are water-cooled by the first cooling water in the cooler 6.

[0018] (First heat exchanger, second heat exchanger) The first heat exchanger (first air cooler) 7 is configured to exchange heat between compressed gas (for example, compressed air) that is compressed by the compressor 11 and led to the internal combustion engine 2, and the first cooling water flowing through the first circulation line 4. The second heat exchanger (second air cooler) 8 is configured to exchange heat between compressed gas that has passed through the first heat exchanger 7 and the second cooling water flowing through the second circulation line 5.

[0019] As shown in Figure 1, the internal combustion engine system 10 comprises a water cooling system 1, an internal combustion engine 2 having a plurality of cylinders 21, a compressor 11 for compressing a combustion gas (e.g., air) that is introduced into the plurality of cylinders 21 of the internal combustion engine 2, and a compressed gas introduction line 12 which is a flow path for introducing the compressed gas compressed by the compressor 11 into the plurality of cylinders 21 of the internal combustion engine 2. The compressed gas introduction line 12 is provided with a first heat exchanger 7 and a second heat exchanger 8. The second heat exchanger 8 is provided downstream of the first heat exchanger 7 in the compressed gas flow direction of the compressed gas introduction line 12.

[0020] The compressed gas compressed by the compressor 11 is heated and pressurized to a higher temperature than before it was introduced into the compressor 11. The compressed gas compressed by the compressor 11 is cooled by the first cooling water in the first heat exchanger 7, and then cooled by the second cooling water in the second heat exchanger 8. The compressed gas that has passed through the second heat exchanger 8 is then led to the internal combustion engine 2.

[0021] (Compressed Gas Cooling Line) The first circulation line 4 includes a compressed gas cooling line 45, which is provided in parallel with the component cooling line 44, where the cooler 6 is located, as shown in Figure 1. The first heat exchanger 7 is provided in the compressed gas cooling line 45. The first heat exchanger 7 is configured to perform heat exchange between the compressed gas, which is compressed by the compressor 11 and led to the internal combustion engine 2, and the first cooling water flowing through the compressed gas cooling line 45.

[0022] In the illustrated embodiment, the first circulation line 4 branches into a component cooling line 44 and a compressed gas cooling line 45 at a branching section 401 located downstream of the first pump 42 in the flow direction of the first cooling water in the first circulation line 4. The component cooling line 44 and the compressed gas cooling line 45 merge at a confluence section 402 located downstream of the branching section 401 in the flow direction of the first cooling water in the first circulation line 4. The component cooling line 44 and the compressed gas cooling line 45 are respective flow paths through which the first cooling water flows, with the branching section 401 as the upstream end and the confluence section 402 as the downstream end.

[0023] In the illustrated embodiment, the confluence section 402 is located upstream of the first coolant inlet 412 of the first radiator 41 in the direction of the first coolant flow. However, it may also be located in the middle of the first radiator 41, that is, between the first coolant outlet 411 and the first coolant inlet 412 of the first radiator 41.

[0024] A portion of the first cooling water flowing through the first circulation line 4 is guided to the component cooling line 44, where it cools the component 3 in the cooler 6 and is heated by the thermal energy recovered from the component 3. The remaining first cooling water flowing through the first circulation line 4 is guided to the compressed gas cooling line 45, where it cools the compressed gas in the first heat exchanger 7 and is heated by the thermal energy recovered from the compressed gas.

[0025] (Water-cooling system for an internal combustion engine according to a comparative example) Figure 2 is a schematic diagram showing the configuration of an internal combustion engine system 010 equipped with a water-cooling system 01 for an internal combustion engine 2 according to a comparative example. As shown in Figure 2, the water-cooling system 01 for an internal combustion engine 2 according to a comparative example comprises a first circulation line 4, a second circulation line 5, a cooler 6, a first heat exchanger 7, and a second heat exchanger 8, similar to the water-cooling system 1 shown in Figure 1. The water-cooling system 01 for an internal combustion engine 2 according to a comparative example differs from the water-cooling system 1 of this disclosure in that the first circulation line 4 does not include a compressed gas cooling line 45, and the first heat exchanger 7 is provided downstream of the cooler 6 in the first cooling water flow direction of the first circulation line 4 (component equipment cooling line 44).

[0026] In the comparative example water cooling system 01, a cooler 6 and a first heat exchanger 7 are provided in series in the first circulation line 4. In contrast, in the water cooling system 1 of the present disclosure, a cooler 6 and a first heat exchanger 7 are provided in parallel in the first circulation line 4. The water cooling system 1 of the present disclosure (see Figure 1) can reduce the overall pressure loss of the first circulation line 4 compared to the comparative example water cooling system 01 (see Figure 2).

[0027] If the components of the water cooling system 1 of this disclosure (see Figure 1) are the same as those of the water cooling system 01 of the internal combustion engine 2 of the comparative example (see Figure 2), and the rotational speed of the first pump 42 is kept the same, the water cooling system 1 of this disclosure reduces the pressure loss of the entire first circulation line 4, thereby increasing the discharge volume of the first pump 42 compared to the water cooling system 01 of the comparative example, and consequently increasing the flow rate of the first cooling water circulating in the first circulation line 4. By keeping the flow rate of the first cooling water circulating in the first circulation line 4 above a predetermined amount, the risk of cavitation generation in the first pump 42 can be reduced.

[0028] The water cooling system 1 of this disclosure can achieve a flow rate of first cooling water directed to the cooler 6 that is equal to or greater than that of the comparative example water cooling system 01. The flow rate of first cooling water directed to the cooler 6 has a relatively large impact on the heat recovery efficiency of the cooler 6. The water cooling system 1 of this disclosure can secure the required amount of flow rate of first cooling water directed to the cooler 6, allowing the cooler 6 to fully demonstrate its cooling performance.

[0029] The water cooling system 1 of this disclosure can reduce the temperature (inlet temperature) of the first cooling water introduced to the first heat exchanger 7 compared to the water cooling system 01 of the comparative example, and can increase the temperature difference between the compressed gas and the first cooling water in the first heat exchanger 7, thereby increasing the amount of heat exchanged in the first heat exchanger 7. Here, the effect of the flow rate of the first cooling water introduced to the first heat exchanger 7 on the heat recovery efficiency of the first heat exchanger 7 is smaller than the effect of the temperature of the first cooling water on the heat recovery efficiency of the first heat exchanger 7. Even if the flow rate of the first cooling water introduced to the first heat exchanger 7 is greater than the required amount, the effect on the heat recovery efficiency of the first heat exchanger 7 is small. The water cooling system 1 of this disclosure can secure the required amount of flow rate of the first cooling water introduced to the first heat exchanger 7 by providing a compressed gas cooling line 45, and can allow the first heat exchanger 7 to fully demonstrate its cooling performance.

[0030] Furthermore, if the required amount of flow rate of the first cooling water supplied to the cooler 6 and the first heat exchanger 7 can be secured, the water cooling system 1 of this disclosure can also be made smaller than the water cooling system 01 of the comparative example, while suppressing a decrease in the cooling performance of the cooler 6 and the first heat exchanger 7, by making at least one of the first radiator 41 or the first pump 42 smaller.

[0031] In some embodiments of the water cooling system 1 for the internal combustion engine 2, as shown in Figure 1, the components 3 of the internal combustion engine 2 described above include an engine jacket 31 for cooling the cylinders 21 of the internal combustion engine 2. The engine jacket 31 forms an internal space surrounding the cylinders 21 in the internal combustion engine 2. In the illustrated embodiment, the engine jacket 31 constitutes part of the cooler 6 and is provided in the component cooling line 44 and is cooled by first cooling water guided into the internal space. By cooling the engine jacket 31 with the first cooling water in the cooler 6, the cylinders 21 of the internal combustion engine 2 can be cooled.

[0032] In some embodiments of the water cooling system 1 for the internal combustion engine 2, as shown in Figure 1, the components 3 of the internal combustion engine 2 described above further include an oil cooler 32 for cooling the lubricating oil of the internal combustion engine 2. The cooler 6 is configured to cool the engine jacket 31 with first coolant that has passed through the oil cooler 32.

[0033] As shown in Figure 1, the internal combustion engine system 10 includes a lubricating oil storage tank (e.g., an oil pan) 13 configured to store lubricating oil for the internal combustion engine 2, a lubricating oil circulation line 14 which is a passage for drawing out and circulating the circulating oil stored in the circulating oil storage tank 13, and a lubricating oil pump 15 provided in the lubricating oil circulation line 14 for supplying lubricating oil in the lubricating oil circulation line 14. The lubricating oil flows through the lubricating oil circulation line 14 downstream in the direction of lubricating oil flow by driving the lubricating oil pump 15.

[0034] In the illustrated embodiment, the oil cooler 32 constitutes part of the cooler 6 and is provided in the lubricating oil circulation line 14. The first cooling water introduced to the oil cooler 32 cools the circulating oil introduced to the oil cooler 32.

[0035] In the cooler 6, the oil cooler 32 is cooled by the first coolant, thereby cooling the lubricating oil of the internal combustion engine 2. The amount of thermal energy recovered by the first coolant from the oil cooler 32 (the increase in the temperature of the first coolant) is smaller than the amount of thermal energy recovered by the first coolant from the engine jacket 31 (the increase in the temperature of the first coolant). Therefore, by installing the oil cooler 32 upstream of the engine jacket 31 in the flow direction of the first coolant, the engine jacket 31 and the oil cooler 32 can be effectively cooled by the first coolant.

[0036] In some other embodiments, the cooler 6 may be composed of either the engine jacket 31 or the oil cooler 32.

[0037] (First Bypass Line, First Thermostat) In some embodiments of the water cooling system 1 of the internal combustion engine 2, as shown in Figure 1, a first bypass line 46 and a first thermostat 47 for opening and closing the first bypass line 46 are provided. One side of the first bypass line 46 is connected downstream in the flow direction of the first coolant from the engine jacket 31 (the downstreammost component 3) of the component cooling line 44. The other side of the first bypass line 46 is connected upstream in the flow direction of the first coolant from the branching point 401 that branches the first circulation line 4 into the component cooling line 44 and the compressed gas cooling line 45. In the illustrated embodiment, the other side of the first bypass line 46 is connected upstream in the flow direction of the first coolant from the first pump 42 of the first circulation line 4. The first thermostat 47 is provided at the connection point between one side of the first bypass line 46 and the component cooling line 44. Since there is an upper limit to the flow rate of the first cooling water that can pass through the first thermostat 47, the flow path in which the first thermostat 47 is provided may be made into a plurality of parallel flow paths, and the first thermostat 47 may be provided in each of the plurality of parallel flow paths.

[0038] The first thermostat 47 is configured such that the first coolant flowing upstream of the connection point with one side of the first bypass line 46 in the component cooling line 44 passes through either the first radiator 41 or the first bypass line 46. The first thermostat 47 is configured to open the flow path toward the first bypass line 46 and close the flow path toward the first radiator 41 when the temperature of the first coolant introduced into the first thermostat 47 is below a set temperature. Furthermore, the first thermostat 47 is configured to open the flow path toward the first radiator 41 and close the flow path toward the first bypass line 46 when the temperature of the first coolant introduced into the first thermostat 47 exceeds a set temperature.

[0039] The first thermostat 47 allows the first coolant that has passed through the engine jacket 31 (component 3) to be selectively directed to either the first radiator 41 or the first bypass line 46 depending on the temperature of the first coolant. The water cooling system 1 of the internal combustion engine 2 equipped with the first thermostat 47 can maintain the temperature of the first coolant flowing through the first circulation line 4 near a set temperature without requiring a dedicated thermostat to be provided downstream of the first heat exchanger 7 in the compressed gas cooling line 45 in the direction of the first coolant flow. By not providing the dedicated thermostat in the compressed gas cooling line 45, the water cooling system 1 of the internal combustion engine 2 can reduce the pressure loss in the compressed gas cooling line 45, thereby increasing the flow rate of the first coolant circulating through the first circulation line 4. Furthermore, by not providing the dedicated thermostat in the compressed gas cooling line 45, the water cooling system 1 of the internal combustion engine 2 can simplify the structure of the water cooling system 1 and reduce the manufacturing cost of the water cooling system 1.

[0040] A comparative example water cooling system 01 (see Figure 2) includes, similar to the water cooling system 1 of this disclosure, a first bypass line 046 and a first thermostat 047 for opening and closing the first bypass line 046. One side of the first bypass line 046 is connected downstream of the first heat exchanger 7 of the first circulation line 4 (component equipment cooling line 44) in the flow direction of the first cooling water. The other side of the first bypass line 046 is connected upstream of the first pump 42 and cooler 6 of the first circulation line 4 (component equipment cooling line 44) in the flow direction of the first cooling water.

[0041] (Second Bypass Line, Second Thermostat) In some embodiments of the water cooling system 1 of the internal combustion engine 2, as shown in Figure 1, a second bypass line 54 and a second thermostat 55 for opening and closing the second bypass line 54 are provided. One end of the second bypass line 54 is connected downstream of the second heat exchanger 8 of the second circulation line 5 in the flow direction of the second cooling water. The other end of the second bypass line 54 is connected upstream of the second heat exchanger 8 of the second circulation line 5 in the flow direction of the second cooling water. In the illustrated embodiment, the other end of the second bypass line 54 is connected upstream of the second pump 52 of the second circulation line 5 in the flow direction of the second cooling water. The second thermostat 55 is provided at the connection point between one end of the second bypass line 54 and the second circulation line 5. Since there is an upper limit to the flow rate of the second cooling water that can pass through the second thermostat 55, the flow path in which the second thermostat 55 is provided may be made into a plurality of parallel flow paths, and the second thermostat 55 may be provided in each of the plurality of parallel flow paths.

[0042] The second thermostat 55 is configured such that the second coolant flowing upstream of the connection point with one side of the second bypass line 54 in the second circulation line 5 passes through either the second radiator 51 or the second bypass line 54. The second thermostat 55 is configured to open the flow path toward the second bypass line 54 and close the flow path toward the second radiator 51 when the temperature of the second coolant introduced into the second thermostat 55 is below the set temperature. Furthermore, the second thermostat 55 is configured to open the flow path toward the second radiator 51 and close the flow path toward the second bypass line 54 when the temperature of the second coolant introduced into the second thermostat 55 exceeds the set temperature.

[0043] The second thermostat 55 allows the second coolant that has passed through the second heat exchanger 8 to be selectively directed to either the second radiator 51 or the second bypass line 54, depending on the temperature of the second coolant. The water cooling system 1 of the internal combustion engine 2 equipped with the second thermostat 55 can maintain the temperature of the second coolant flowing through the second circulation line 5 near a set temperature. If there is no thermostat downstream of the first heat exchanger 7 in the first circulation line 4 (compressed gas cooling line 45) in the flow direction of the first coolant, the warm-up of the internal combustion engine 2 when starting will be slow, and the temperature of the compressed gas after cooling may remain low. However, the temperature of the compressed gas after cooling by the first heat exchanger 7 and the second heat exchanger 8 is predominantly determined by the temperature of the second coolant flowing through the second circulation line 5. In other words, the temperature of the first coolant flowing through the first circulation line 4 is less sensitive to the temperature of the compressed gas after cooling by the second heat exchanger 8. By providing a second thermostat 55 in the second circulation line 5, the warm-up of the internal combustion engine 2 during startup can be accelerated, and supercooling of the compressed gas during startup can be suppressed. In such a water cooling system 1 for the internal combustion engine 2, it is not necessary to provide a dedicated thermostat downstream of the first heat exchanger 7 in the first cooling water flow direction in the compressed gas cooling line 45.

[0044] In the water-cooling system 1 of the internal combustion engine 2 according to some embodiments, the flow rate of the first cooling water guided to the compressed gas cooling line 45 described above is configured to be smaller than the flow rate of the first cooling water guided to the component equipment cooling line 44. For example, in order to adjust the flow rate of the first cooling water flowing through the component equipment cooling line 44 and the compressed gas cooling line 45, the inner diameter of the pipes constituting the component equipment cooling line 44 and the compressed gas cooling line 45 may be adjusted. In a certain embodiment, when the discharge amount of the first pump 42 is defined as 100%, a flow rate of 20% or more and 40% or less flows through the compressed gas cooling line 45.

[0045] The cooler 6 is such that the influence of the flow rate of the first cooling water guided to the cooler 6 on the heat recovery efficiency of the cooler 6 is relatively large. In contrast, for the first heat exchanger 7, the influence of the flow rate of the first cooling water guided to the first heat exchanger 7 on the heat recovery efficiency of the first heat exchanger 7 is relatively small. The water-cooling system 1 of the internal combustion engine 2 can effectively exhibit the cooling performance of the cooler 6 and the first heat exchanger 7 by making the flow rate of the first cooling water guided to the component equipment cooling line 44 relatively large and making the flow rate of the first cooling water guided to the compressed gas cooling line 45 provided with the first heat exchanger 7 relatively small.

[0046] (Orifice) FIG. 3 is an explanatory diagram for explaining an orifice 101 in the water-cooling system 1 of the internal combustion engine 2 according to an embodiment of the present disclosure. The water-cooling system 1 of the internal combustion engine 2 according to some embodiments includes an orifice 101 (101A, 101B) provided in at least one of the compressed gas cooling line 45 or the component equipment cooling line 44 as shown in FIG. 3. The orifice 101 has an opening that reduces the flow path cross-sectional area compared to other portions of the flow path in which the orifice 101 is provided.

[0047] In the embodiment shown in FIG. 3, the first circulation line 4 includes a pipe 102 including a portion constituting the above-described branch portion 401, a pipe 103 on the side of the component equipment cooling line 44 connected to the pipe 102, and a pipe 104 on the side of the compressed gas cooling line 45 connected to the pipe 102. The orifice 101 includes a first orifice 101A installed between the pipe 102 and the pipe 103, and a second orifice 101B installed between the pipe 102 and the pipe 104. Note that the orifice 101 may be only one of the first orifice 101A or the second orifice 101B. Further, the orifice 101 may be provided at a portion other than the portion shown in FIG. 3 of the compressed gas cooling line 45 or the component equipment cooling line 44.

[0048] The water cooling system 1 of the internal combustion engine 2 can adjust the flow rate of the first cooling water guided to each of the compressed gas cooling line 45 and the component equipment cooling line 44 by the orifice 101 to an appropriate amount. By making the flow rate of the first cooling water guided to each of the compressed gas cooling line 45 and the component equipment cooling line 44 an appropriate amount, the water cooling system 1 of the internal combustion engine 2 can effectively exhibit the cooling performance of the cooler 6 and the first heat exchanger 7.

[0049] (First Component Equipment Cooling Line, Second Component Equipment Cooling Line) The internal combustion engine 2 in FIG. 1 is schematically shown in a state viewed from above. In some embodiments, as shown in FIG. 1, the above-described internal combustion engine 2 includes a first cylinder row 21A to which a plurality of cylinders 21 arranged at intervals along a predetermined cylinder row direction (vertical direction in FIG. 1) belong, and a first cylinder row 21A in a direction intersecting (orthogonal) the cylinder row direction. And a second cylinder row 21B to which a plurality of cylinders 21 arranged at intervals along the cylinder row direction are arranged. The above-described component equipment cooling line 44 includes a first component equipment cooling line 44A and a second component equipment cooling line 44B provided in parallel with the first component equipment cooling line 44A.

[0050] In the embodiment shown in Figure 1, the component cooling line 44 branches into a first component cooling line 44A and a second component cooling line 44B at a branching section 441 provided in the component cooling line 44. The first component cooling line 44A and the second component cooling line 44B merge at a confluence section 442 located downstream of the branching section 441 in the flow direction of the first cooling water.

[0051] Figures 4 and 5 are explanatory diagrams illustrating modified examples of the first component cooling line 44A and the second component cooling line 44B, respectively. In some embodiments, the first circulation line 4 may branch at the branching section 401 into a compressed gas cooling line 45, the first component cooling line 44A, and the second component cooling line 44B, as shown in Figure 4. In some embodiments, the first circulation line 4 may merge at the confluence section 402 into the compressed gas cooling line 45, the first component cooling line 44A, and the second component cooling line 44B, as shown in Figure 4.

[0052] The first circulation line 4 may include multiple branching sections 401 (401A, 401B) and multiple merging sections 402 (402A, 402B) if there are multiple component cooling lines 44 (44A, 44B). The first bypass line 46 is preferably connected upstream of the branching section 401 (401A, 401B) located furthest upstream in the flow direction of the first cooling water. In some embodiments, as shown in Figure 5, the first circulation line 4 branches at branching section 401A (401) of the first circulation line 4 into either the first component cooling line 44A or the second component cooling line 44B (in the illustrated example, the second component cooling line 44B) and a compressed gas cooling line 45. As shown in Figure 5, the first circulation line 4 may have a branch at a branch 401B located downstream of the branch 401A of the first circulation line 4 in the flow direction of the first cooling water, where the other component cooling line (in the illustrated example, the first component cooling line 44A) may branch off from the compressed gas cooling line 45. In some embodiments, as shown in Figure 5, the first circulation line 4 has a confluence 402A (402) where the compressed gas cooling line 45 merges with either the first component cooling line 44A or the second component cooling line 44B (in the illustrated example, the second component cooling line 44B). As shown in Figure 5, the first circulation line 4 may have a branching section 402B located upstream of the confluence section 402A of the first circulation line 4 in the flow direction of the first cooling water, where the other component cooling line (in the illustrated example, the first component cooling line 44A) may merge with the compressed gas cooling line 45.

[0053] The first component cooling line 44A is provided with a first engine jacket 31A, which is an engine jacket 31 for cooling a plurality of cylinders 21 belonging to the first cylinder row 21A. The first engine jacket 31A forms an internal space surrounding the plurality of cylinders 21 belonging to the first cylinder row 21A. By cooling the first engine jacket 31A, the first cylinder row 21A can be cooled.

[0054] The second component cooling line 44B is provided with a second engine jacket 31B, which is an engine jacket 31 for cooling a plurality of cylinders 21 belonging to the second cylinder row 21B. The second engine jacket 31B forms an internal space surrounding the plurality of cylinders 21 belonging to the second cylinder row 21B. By cooling the second engine jacket 31B, the second cylinder row 21B can be cooled.

[0055] The first cooling water cooled by the first radiator 41 can be directly supplied to the first component cooling line 44A and the second component cooling line 44B, respectively. In this case, the first engine jacket 31A and the second engine jacket 31B are water-cooled by the relatively low-temperature first cooling water, so that the multiple cylinders 21 belonging to the first cylinder row 21A and the multiple cylinders 21 belonging to the second cylinder row 21B can be effectively cooled.

[0056] In some embodiments, as shown in Figure 1, the oil cooler 32 described above includes a first oil cooler 32A provided upstream of the first engine jacket 31A in the flow direction of the first coolant in the first component cooling line 44A, and a second oil cooler 32B provided upstream of the second engine jacket 31B in the flow direction of the first coolant in the second component cooling line 44B. In the illustrated embodiment, the second oil cooler 32B is provided in parallel with the first oil cooler 32A in the lubricating oil circulation line 14. The lubricating oil circulation line 14 includes a flow path provided with the first oil cooler 32A, and a flow path parallel to the first oil cooler 32A and provided with the second oil cooler 32B. In this case, the first oil cooler 32A and the second oil cooler 32B are water-cooled by the first coolant at a relatively low temperature, so that the lubricating oil of the internal combustion engine 2 can be effectively cooled.

[0057] As shown in Figure 1, an internal combustion engine system 10 according to several embodiments comprises the water cooling system 1 described above, the internal combustion engine 2 described above, and the compressor 11 described above. An internal combustion engine system 10 equipped with the water cooling system 1 for the internal combustion engine 2 can fully utilize the cooling performance of the cooler 6 for cooling the components 3 of the internal combustion engine 2 and the first heat exchanger 7 for cooling the compressed gas introduced into the internal combustion engine 2.

[0058] A method for modifying the water cooling system 1 of an internal combustion engine 2 according to several embodiments is a method for modifying the water cooling system 01 of the internal combustion engine 2 shown in Figure 2 to the water cooling system 1 of the present disclosure shown in Figure 1. The method for modifying the water cooling system 1 of the internal combustion engine 2 includes a compressed gas cooling line addition step of adding a compressed gas cooling line 45 in parallel with the component cooling line 44 on which the cooler 6 of the first circulation line 4 is provided, and a first heat exchanger relocation step of moving the first heat exchanger 7, which is provided in series with the cooler 6 in the component cooling line 44, from the component cooling line 44 to the compressed gas cooling line 45. In the first heat exchanger relocation step, the first heat exchanger 7 is removed from the component cooling line 44, the component cooling line 44 from which the first heat exchanger 7 was removed is reconnected, and the first heat exchanger 7 is installed in the compressed gas cooling line 45.

[0059] The modified water cooling system 1 (see Figure 1) reduces the overall pressure loss in the first circulation line 4 compared to the pre-modification water cooling system 01 (see Figure 2), in which the cooler 6 and the first heat exchanger 7 were connected in series. This allows for an increase in the flow rate of the first cooling water circulating in the first circulation line 4. The modified water cooling system 1 of the internal combustion engine 2 can secure the necessary flow rate of the first cooling water supplied to the cooler 6 and the first heat exchanger 7, respectively, allowing the cooler 6 and the first heat exchanger 7 to fully demonstrate their cooling performance.

[0060] In this specification, expressions describing relative or absolute arrangements such as "in a certain direction," "along a certain direction," "parallel," "orthogonal," "center," "concentric," or "coaxial" shall not only describe such arrangements strictly, but also describe states of relative displacement with tolerances or angles or distances sufficient to achieve the same function. For example, expressions describing things being in an equal state such as "identical," "equal," and "homogeneous" shall not only describe states of being strictly equal, but also describe states where tolerances or differences exist to the extent that the same function is achieved. Furthermore, in this specification, expressions describing shapes such as quadrilaterals or cylindrical shapes shall not only describe geometrically precise quadrilaterals or cylindrical shapes, but also describe shapes including concave and concave parts, chamfered parts, etc., to the extent that the same effect is achieved. In addition, in this specification, expressions such as "equipment," "includes," or "possesses" a component are not exclusive expressions that exclude the existence of other components.

[0061] This disclosure is not limited to the embodiments described above, but also includes modified forms of the embodiments described above, as well as forms that combine these forms as appropriate.

[0062] The contents described in some of the embodiments above can be understood, for example, as follows:

[0063] 1) A water cooling system (1) for an internal combustion engine (2) according to at least one embodiment of the present disclosure is a water cooling system (1) for an internal combustion engine (2) for cooling components (3) of the internal combustion engine (2) and compressed gas led to the internal combustion engine, comprising: a first circulation line (4) configured to circulate first coolant cooled by a first radiator (41); a cooler (6) configured to cool the components (3) of the internal combustion engine (2) with the first coolant flowing through the first circulation line (4); a first heat exchanger (7) configured to perform heat exchange between the compressed gas compressed by a compressor (11) and led to the internal combustion engine (2) and the first coolant flowing through the first circulation line (4); and a second circulation line (5) configured to circulate second coolant cooled by a second radiator (51) at a lower temperature than the first coolant. The system includes a second heat exchanger (8) configured to perform heat exchange between the compressed gas that has passed through the first heat exchanger (7) and the second cooling water flowing through the second circulation line (5), wherein the first circulation line (4) includes a component cooling line (44) on which the cooler (6) is provided, and a compressed gas cooling line (45) provided in parallel with the component cooling line (44), and the first heat exchanger (7) is configured to perform heat exchange between the compressed gas and the first cooling water flowing through the compressed gas cooling line (45).

[0064] According to the configuration described in 1) above, the water cooling system (1) of the internal combustion engine (2) can reduce the overall pressure loss in the first circulation line (4) compared to the case where the cooler (6) and the first heat exchanger (7) are installed in series, by installing the compressed gas cooling line (45) equipped with the first heat exchanger (7) in parallel with the component cooling line (44) equipped with the cooler (6). This allows for an increase in the flow rate of the first cooling water circulating in the first circulation line (4). The water cooling system (1) of the internal combustion engine (2) can secure the necessary flow rate of the first cooling water supplied to the cooler (6) and the first heat exchanger (7), respectively, and allow the cooler (6) and the first heat exchanger (7) to fully demonstrate their cooling performance.

[0065] 2) In some embodiments, the water cooling system (1) for the internal combustion engine (2) described in 1) above, wherein the components (3) include an engine jacket (31) for cooling the cylinders (21) of the internal combustion engine (2).

[0066] According to the configuration described in 2) above, the cylinders (21) of the internal combustion engine (2) can be cooled by cooling the engine jacket (31) with the first coolant in the cooler (6).

[0067] 3) In some embodiments, the water cooling system (1) for the internal combustion engine (2) described in 2) above, wherein the components (3) further include an oil cooler (32) for cooling the lubricating oil of the internal combustion engine (2), and the cooler (6) is configured to cool the engine jacket (31) with the first coolant that has passed through the oil cooler (32).

[0068] According to the configuration described in 3) above, the lubricating oil of the internal combustion engine (2) can be cooled by cooling the oil cooler (32) with the first coolant in the cooler (6). The amount of thermal energy recovered by the first coolant from the oil cooler (32) (amount of temperature increase of the first coolant) is smaller than the amount of thermal energy recovered by the first coolant from the engine jacket (31) (amount of temperature increase of the first coolant). For this reason, by placing the oil cooler (32) upstream of the engine jacket (31) in the flow direction of the first coolant, the engine jacket (31) and the oil cooler (32) can be effectively cooled by the first coolant.

[0069] 4) In some embodiments, the water cooling system (1) for the internal combustion engine (2) described in 2) or 3) above further comprises: a first bypass line (46) connecting the downstream side of the component cooling line (44) to the engine jacket (31) and the upstream side of the first circulation line (4) to the branch section (401) that branches off to the component cooling line (44) and the compressed gas cooling line (45); and a first thermostat (47) for opening and closing the first bypass line (46).

[0070] According to the configuration of 4) above, the first thermostat (47) can selectively guide the first coolant that has passed through the engine jacket (31) to either the first radiator (41) or the first bypass line (46) depending on the temperature of the first coolant. The water cooling system (1) of the internal combustion engine (2) equipped with the first thermostat (47) can maintain the temperature of the first coolant flowing through the first circulation line (4) near a set temperature without having to provide a dedicated thermostat downstream of the first heat exchanger (7) in the compressed gas cooling line (45) in the direction of the first coolant flow. By not providing the dedicated thermostat in the compressed gas cooling line (45), the water cooling system (1) of the internal combustion engine (2) can reduce the pressure loss in the compressed gas cooling line (45), thereby increasing the flow rate of the first coolant circulating through the first circulation line (4). Furthermore, by not providing the dedicated thermostat in the compressed gas cooling line (45) of the internal combustion engine (2), the structure of the water cooling system (1) can be simplified, and the manufacturing cost of the water cooling system (1) can be reduced.

[0071] 5) In some embodiments, the water cooling system (1) for the internal combustion engine (2) described in 4) further comprises: a second bypass line (54) connecting the second circulation line (5) downstream of the second heat exchanger (8) to the second circulation line (5) upstream of the second heat exchanger (8); and a second thermostat (55) for opening and closing the second bypass line (54).

[0072] According to the configuration of 5) above, the second thermostat (55) can selectively guide the second coolant that has passed through the second heat exchanger (8) to either the second radiator (51) or the second bypass line (54) depending on the temperature of the second coolant. The water cooling system (1) of the internal combustion engine (2) equipped with the second thermostat (55) can maintain the temperature of the second coolant flowing through the second circulation line (5) near a set temperature. By providing the second thermostat (55) in the second circulation line (5), the warm-up of the internal combustion engine (2) during startup can be accelerated, and supercooling of the compressed gas during startup can be suppressed. In such a water cooling system (1) of the internal combustion engine (2), it is not necessary to provide a dedicated thermostat downstream of the first heat exchanger (7) in the first coolant flow direction of the compressed gas cooling line (45).

[0073] 6) In some embodiments, a water cooling system (1) for an internal combustion engine (2) as described in any of 2) to 5) above, wherein the flow rate of the first cooling water led to the compressed gas cooling line (45) is configured to be smaller than the flow rate of the first cooling water led to the component cooling line (44).

[0074] According to the configuration described in 6) above, the flow rate of the first cooling water supplied to the cooler (6) has a relatively large impact on the heat recovery efficiency of the cooler (6). In contrast, the flow rate of the first cooling water supplied to the first heat exchanger (7) has a relatively small impact on the heat recovery efficiency of the first heat exchanger (7). The water cooling system (1) of the internal combustion engine (2) can effectively utilize the cooling performance of the cooler (6) and the first heat exchanger (7) by relatively increasing the flow rate of the first cooling water supplied to the component cooling line (44) and relatively decreasing the flow rate of the first cooling water supplied to the compressed gas cooling line (45) where the first heat exchanger (7) is installed.

[0075] 7) In some embodiments, the water cooling system (1) for the internal combustion engine (2) described in 6) above comprises an orifice (101) provided in at least one of the compressed gas cooling line (45) or the component cooling line (44).

[0076] According to the configuration described in 7) above, the water cooling system (1) of the internal combustion engine (2) can adjust the flow rate of the first cooling water supplied to the compressed gas cooling line (45) and the component cooling line (44) via the orifice (101) to an appropriate amount. By adjusting the flow rate of the first cooling water supplied to the compressed gas cooling line (45) and the component cooling line (44) to an appropriate amount, the water cooling system (1) of the internal combustion engine (2) can effectively utilize the cooling performance of the cooler (6) and the first heat exchanger (7).

[0077] 8) In some embodiments, a water cooling system (1) for an internal combustion engine (2) as described in any of 2) to 7) above, wherein the internal combustion engine (2) has: a first cylinder row (21A) to which a plurality of cylinders (21) arranged at intervals along a predetermined cylinder row direction belongs; a second cylinder row (21B) to which a plurality of cylinders (21) arranged at intervals along the cylinder row direction is offset from the first cylinder row (21A) in a direction intersecting the cylinder row direction; and the component cooling line (44) has: a first component cooling line (44A) to which a first engine jacket (31A) which is the engine jacket (31) for cooling a plurality of cylinders (21) belonging to the first cylinder row (21A) is provided; The system includes a second component cooling line (44B) provided with a second engine jacket (31B), which is the engine jacket (31) for cooling a plurality of cylinders (21) belonging to the second cylinder row (21B).

[0078] According to the configuration described in 8) above, the first coolant cooled by the first radiator (41) can be directly supplied to the first component cooling line (44A) and the second component cooling line (44B), respectively. In this case, the first engine jacket (31A) and the second engine jacket (31B) are water-cooled by the relatively low temperature first coolant, so that the multiple cylinders (21) belonging to the first cylinder row (21A) and the multiple cylinders (21) belonging to the second cylinder row (21B) can be effectively cooled.

[0079] 9) An internal combustion engine system (10) according to at least one embodiment of the present disclosure comprises: a water cooling system (1) for an internal combustion engine (2) as described in any of 1) to 8) above; the internal combustion engine (2); and the compressor (11).

[0080] According to the configuration in 9) above, the internal combustion engine system (10) equipped with a water cooling system (1) for the internal combustion engine (2) can fully utilize the cooling performance of the cooler (6) for cooling the components (3) of the internal combustion engine (2) and the heat exchanger (first heat exchanger 7) for cooling the compressed gas introduced into the internal combustion engine (2).

[0081] 10) A method for modifying a water cooling system (1) for an internal combustion engine (2) according to at least one embodiment of the present disclosure is a method for modifying a water cooling system (1) for an internal combustion engine (2) for cooling components (3) of the internal combustion engine (2) and compressed gas led to the internal combustion engine (2), wherein the water cooling system (1) for the internal combustion engine (2) comprises: a first circulation line (4) configured to circulate first coolant cooled by a first radiator (41); a cooler (6) configured to cool the components (3) of the internal combustion engine (2) with the first coolant flowing through the first circulation line (4); a first heat exchanger (7) configured to perform heat exchange between the compressed gas compressed by a compressor (11) and led to the internal combustion engine (2) and the first coolant flowing through the first circulation line (4); and a second circulation line (5) configured to circulate second coolant at a lower temperature than the first coolant cooled by a second radiator (51). A method for modifying the water cooling system (1) of an internal combustion engine (2) comprises a second heat exchanger (8) configured to perform heat exchange between the compressed gas that has passed through the first heat exchanger (7) and the second cooling water that flows through the second circulation line (5), the method for modifying the water cooling system (1) of the internal combustion engine (2) comprises: a compressed gas cooling line addition step of adding a compressed gas cooling line (45) which is in parallel with the component cooling line (44) on which the cooler (6) of the first circulation line (4) is provided; and a first heat exchanger relocation step of moving the first heat exchanger (7), which is provided in series with respect to the cooler (6) on the component cooling line (44), from the component cooling line (44) to the compressed gas cooling line (45).

[0082] According to the method described in 10) above, the water cooling system (1) of the modified internal combustion engine (2) has a compressed gas cooling line (45) equipped with a first heat exchanger (7) in parallel with the component cooling line (44) equipped with a cooler (6). Compared to the water cooling system (01) of the internal combustion engine (2) before modification, in which the cooler (6) and the first heat exchanger (7) are equipped in series, the pressure loss of the entire first circulation line (4) can be reduced, thereby increasing the flow rate of the first cooling water circulating in the first circulation line (4). The water cooling system (1) of the modified internal combustion engine (2) can secure the necessary amount of flow rate of the first cooling water supplied to the cooler (6) and the first heat exchanger (7), respectively, and allow the cooler (6) and the first heat exchanger (7), respectively, to fully demonstrate their cooling performance.

[0083] 1.01 Water cooling system 2 Internal combustion engine 3 Components 4 First circulation line 5 Second circulation line 6 Cooler 7 First heat exchanger 8 Second heat exchanger 10.010 Internal combustion engine system 11 Compressor 12 Compressed gas introduction line 13 Lubricating oil storage tank 14 Lubricating oil circulation line 15 Lubricating oil pump 21 Cylinder 40 First cooling device 41 First radiator 42 First pump 43 First fan 44 Component cooling line 45 Compressed gas cooling line 50 Second cooling device 51 Second radiator 52 Second pump 53 Second fan 101 Orifice

Claims

1. A water cooling system for an internal combustion engine for cooling the components of the internal combustion engine and the compressed gas directed to the internal combustion engine, comprising: a first circulation line configured to circulate first coolant cooled by a first radiator; a cooler configured to cool the components of the internal combustion engine with the first coolant flowing through the first circulation line; a first heat exchanger configured to perform heat exchange between the compressed gas compressed by a compressor and directed to the internal combustion engine and the first coolant flowing through the first circulation line; a second circulation line configured to circulate second coolant cooled by a second radiator and at a lower temperature than the first coolant; and a second heat exchanger configured to perform heat exchange between the compressed gas that has passed through the first heat exchanger and the second coolant flowing through the second circulation line, wherein the first circulation line includes a components cooling line to which the cooler is provided and a compressed gas cooling line provided in parallel with the components cooling line. A water cooling system for an internal combustion engine, wherein the first heat exchanger is configured to perform heat exchange between the compressed gas and the first cooling water flowing through the compressed gas cooling line.

2. The water cooling system for an internal combustion engine according to claim 1, wherein the components include an engine jacket for cooling the cylinders of the internal combustion engine.

3. The water cooling system for an internal combustion engine according to claim 2, wherein the components further include an oil cooler for cooling the lubricating oil of the internal combustion engine, and the cooler is configured to cool the engine jacket with the first coolant that has passed through the oil cooler.

4. A water cooling system for an internal combustion engine according to claim 2 or 3, further comprising: a first bypass line connecting the downstream side of the component cooling line to the engine jacket and the upstream side of the branching point of the first circulation line that branches to the component cooling line and the compressed gas cooling line; and a first thermostat for opening and closing the first bypass line.

5. A water cooling system for an internal combustion engine according to claim 4, further comprising: a second bypass line connecting the second circulation line downstream of the second heat exchanger to the second circulation line upstream of the second heat exchanger; and a second thermostat for opening and closing the second bypass line.

6. The water cooling system for an internal combustion engine according to claim 2 or 3, wherein the flow rate of the first cooling water led to the compressed gas cooling line is configured to be less than the flow rate of the first cooling water led to the component cooling line.

7. The water cooling system for an internal combustion engine according to claim 6, further comprising an orifice provided in at least one of the compressed gas cooling line or the component cooling line.

8. The water cooling system for an internal combustion engine according to claim 2 or 3, wherein the internal combustion engine comprises a first cylinder row to which a plurality of cylinders are spaced apart along a predetermined cylinder row direction, and a second cylinder row to which a plurality of cylinders are spaced apart along the cylinder row direction and are offset from the first cylinder row in a direction intersecting the cylinder row direction, and the component cooling line comprises a first component cooling line provided with a first engine jacket which is the engine jacket for cooling a plurality of cylinders belonging to the first cylinder row, and a second component cooling line provided with a second engine jacket which is the engine jacket for cooling a plurality of cylinders belonging to the second cylinder row.

9. An internal combustion engine system comprising: a water cooling system for an internal combustion engine according to any one of claims 1 to 3; the internal combustion engine; and the compressor.

10. A method for modifying a water cooling system for an internal combustion engine to cool the components of the internal combustion engine and the compressed gas introduced into the internal combustion engine, wherein the water cooling system for the internal combustion engine comprises: a first circulation line configured to circulate first coolant cooled by a first radiator; a cooler configured to cool the components of the internal combustion engine with the first coolant flowing through the first circulation line; a first heat exchanger configured to perform heat exchange between the compressed gas compressed by a compressor and introduced into the internal combustion engine and the first coolant flowing through the first circulation line; a second circulation line configured to circulate second coolant cooled by a second radiator at a lower temperature than the first coolant; and a second heat exchanger configured to perform heat exchange between the compressed gas that has passed through the first heat exchanger and the second coolant flowing through the second circulation line, the method for modifying the water cooling system for the internal combustion engine comprising: a compressed gas cooling line addition step of adding a compressed gas cooling line which is in parallel with the component cooling line in which the cooler of the first circulation line is provided; A method for modifying a water cooling system for an internal combustion engine, comprising: a first heat exchanger relocation step of relocating the first heat exchanger, which is provided in series with the cooler in the component cooling line, from the component cooling line to the compressed gas cooling line.

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