Cooling water flow control device for cooling system of vehicle

Abstract

A cooling water flow control device for a cooling system of a vehicle, capable of shortening the heating time of cooling water supplied to an exhaust gas recirculation cooler. The cooling water flow control device includes: an exhaust gas recirculation cooler that uses cooling water to cool exhaust gas supplied to an intake system of an engine, and includes an exhaust gas recirculation cooler outlet through which cooling water is discharged; a water pump to circulate cooling water to the exhaust gas recirculation cooler and the engine when the engine is started; and a straight flow path connected to a vent hole formed in the engine to guide cooling water from the vent hole to the downstream side of the exhaust gas recirculation cooler outlet.

Description

Technical Field

[0001] The present disclosure relates to a cooling water flow control device for a cooling system of a vehicle. Background Art

[0002] The statements in this section merely provide background information related to the present disclosure and may not constitute prior art.

[0003] Generally, an exhaust gas recirculation (EGR) cooler is used to reduce the temperature of engine exhaust gas in the process of recirculating the exhaust gas to the intake system. The exhaust gas supplied to the engine through the exhaust gas recirculation cooler is reburned, and thus nitrogen oxides included in the exhaust gas are burned, thereby being able to reduce toxic substances in the exhaust gas discharged outside the vehicle.

[0004] This exhaust gas recirculation cooler uses cooling water for engine cooling to cool the exhaust gas. To this end, the exhaust gas recirculation cooler is configured so that heat can be exchanged between the cooling water supplied by the water pump and the exhaust gas supplied from the exhaust system.

[0005] According to the exhaust gas recirculation cooler in the related art, in order to ensure the durability of high-temperature exhaust gas, cooling water can be circulated before the cooling water circulates in the engine when the engine is started, and in this case, the temperature of the cooling water circulating in the exhaust gas recirculation cooler is lower than the temperature of the cooling water stored in the water jacket provided inside the engine.

[0006] According to the EGR cooler as described above, cooling water having a temperature lower than that of cooling water inside the engine continues to circulate from the initial engine start, and this may result in a prolonged heating time of the cooling water on the EGR cooler.

[0007] Meanwhile, if the temperature of cooling water circulating in the EGR cooler is equal to or lower than a predetermined cold temperature, condensed water is generated in the EGR cooler, and in severe cases, a large amount of condensed water is generated and accumulated in the EGR cooler.

[0008] The condensed water generated in the exhaust gas recirculation cooler is high-density acidic condensed water, and therefore it causes corrosion inside the exhaust gas recirculation cooler. If the inside of the exhaust gas recirculation cooler is corroded, the cooling water is mixed with the recirculated exhaust gas supplied to the engine, and therefore engine failure may occur, resulting in a very dangerous situation.

[0009] According to the exhaust gas recirculation system in the related art, if the temperature of the cooling water in the exhaust gas recirculation cooler is equal to or lower than the predetermined temperature, the exhaust gas recirculation cooler does not operate, and if the exhaust gas recirculation cooler cannot be used as described above, it is impossible to improve the vehicle fuel economy by the operation of the exhaust gas recirculation cooler.

[0010] The above information disclosed in this Background section is only for enhancement of understanding of the background of the present disclosure and therefore it may contain information that does not form the prior art already known to a person skilled in the art. Summary of the invention

[0011] The present disclosure provides a cooling water flow control device for a cooling system of a vehicle, which can shorten the heating time of cooling water supplied to an exhaust gas recirculation cooler by shortening the heating time, which is for increasing the temperature of the cooling water supplied from the exhaust gas recirculation cooler to a water pump to an appropriate temperature when the engine is started.

[0012] To this end, the cooling water flow control device as described above is configured to supply a portion of the cooling water exhausted from the engine interior to the cooling water outlet of the exhaust gas recirculation cooler for a predetermined period of time when the engine is started.

[0013] The objects of the present disclosure are not limited to those described above, and other unmentioned objects of the present disclosure may be understood through the following explanation and may be more clearly known through the form of the present disclosure.

[0014] In one aspect of the present disclosure, a cooling water flow control device for a cooling system of a vehicle includes: an exhaust gas recirculation cooler, configured to use cooling water to cool exhaust gas supplied to an intake system of an engine, and including an exhaust gas recirculation cooler outlet, through which the cooling water is discharged, wherein the engine is provided with an engine outlet and an air vent for discharging the cooling water; a water pump, configured to circulate cooling water to the exhaust gas recirculation cooler and the engine when the engine is started; and a direct current path, connected to the air vent, and configured to guide the cooling water from the air vent to the downstream side of the exhaust gas recirculation cooler outlet.

[0015] In one form, the cooling water flow control device further includes: a flow control valve capable of opening and closing the through-flow path, and the flow control valve can be installed on the through-flow path and operated in an open mode when the engine is started. In another form, if the ambient temperature when the engine is started is lower than a first predetermined temperature, the flow control valve can be operated to close. In addition, if the ambient temperature when the engine is started is equal to or higher than the first predetermined temperature, the flow control valve can be operated to open.

[0016] In another form, the cooling water flow control device may further include: a thermal management module configured to perform thermal management of the cooling water and installed on the downstream side of the engine outlet. Specifically, the cooling water discharged from the engine outlet may flow to the water pump through the thermal management module. The thermal management module may be composed of a first valve member installed between the engine outlet and the radiator, a second valve member installed between the engine outlet and the heater, and a third valve member installed between the engine outlet and the automatic transmission fluid cooler.

[0017] The flow control valve may be controlled by a controller, and if the ambient temperature when the engine is started is lower than the first predetermined temperature and the heater is in operation, the controller may allow cooling water exhausted from the engine to flow to the heater by closing the flow control valve and opening the second valve member.

[0018] In addition, if the temperature of the cooling water of the exhaust gas recirculation cooler is overheated to be equal to or higher than a third predetermined temperature, the controller can stop the operation of the exhaust gas recirculation cooler and cause the flow control valve to operate in a closed mode, and if any one of the valve components of the thermal management module is stuck during driving, the controller can cause the flow control valve to operate to open.

[0019] According to the cooling water flow control device of the cooling system for a vehicle disclosed in the present invention, the cooling water (initial cooling water) discharged from the inside of the engine when the engine is started can flow to the cooling water outlet of the exhaust gas recirculation cooler, and thus the heating time of the cooling water circulating in the exhaust gas recirculation cooler can be shortened.

[0020] According to the shortening of the cooling water heating time of the exhaust gas recirculation cooler, the start-up time of the exhaust gas recirculation cooler can be shortened, and thus the exhaust gas recirculation cooler can be used in advance when the engine is started. As a result, the fuel economy improvement operation using the exhaust gas recirculation cooler can be performed in advance when the engine is started, and thus the engine efficiency and the vehicle fuel economy can be improved.

[0021] It should be understood that the term "vehicle" or "transportation vehicle" or other similar terms used herein generally include motor vehicles, such as passenger cars including sport utility vehicles (SUVs), buses, trucks, various commercial vehicles, water vehicles including various boats and large ships, aircraft, etc., and include hybrid vehicles, electric vehicles, plug-in hybrid vehicles, hydrogen-powered vehicles and other alternative fuel vehicles (e.g., fuels derived from resources other than petroleum). As described herein, a hybrid vehicle is a vehicle having two or more power sources, such as both a gasoline-powered vehicle and an electric-powered vehicle.

[0022] Further areas of applicability will become apparent from the description provided herein.It should be understood that the description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to better understand the present disclosure, various forms thereof given by way of example will now be described with reference to the accompanying drawings, in which:

[0024] Figure 1 is a diagram showing a cooling water flow control device informing the present disclosure;

[0025] Figure 2 is a diagram showing another form of cooling water flow control device disclosed in the present invention;

[0026] Figure 3 is a diagram showing a cooling water flow control method during engine startup according to one form of the present disclosure;

[0027] Figure 4 is a schematic diagram showing an exhaust gas recirculation system in one form of the present disclosure;

[0028] Figure 5 is a diagram showing a cooling water flow rate control method during traveling according to another form of the present disclosure; and

[0029] Figure 6 : is a graph showing the experimental results of the effect of shortening the heating time of cooling water in one form of the present disclosure.

[0030] The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way. DETAILED DESCRIPTION

[0031] The following description is merely exemplary in nature and is not intended to limit the present disclosure, application, or uses. It should be understood that throughout the drawings, corresponding reference numerals indicate similar or corresponding parts and features.

[0032] Hereinafter, reference will now be made in detail to various forms of the present disclosure, examples of which are shown in the accompanying drawings and described below. Although the present disclosure will be described in conjunction with the example forms, it will be understood that this description is not intended to limit the present disclosure to those example forms. On the contrary, the present disclosure is intended to cover not only the example forms, but also various alternatives, modifications, equivalents and other forms that may be included in the spirit and scope of the present disclosure defined by the technical solution.

[0033] It should be understood that the accompanying drawings are not necessarily to scale, and that they present somewhat simplified representations of various features illustrating the basic principles of the present disclosure. The specific design features of the present disclosure as disclosed herein, including, for example, specific dimensions, orientations, locations, and shapes, will be determined in part by the specific intended application and use environment.

[0034] A cooling water flow control device for a cooling system of a vehicle according to the present disclosure is configured to shorten a heating time of cooling water supplied to an exhaust gas recirculation cooler when a vehicle engine is started.

[0035] According to the cooling water flow control device, since the heating time of the cooling water discharged from the exhaust gas recirculation cooler and supplied to the water pump when the engine is started can be shortened, the time for the exhaust gas recirculation cooler to start working can be shortened, and thus the fuel economy improvement operation according to the operation of the exhaust gas recirculation cooler can be performed in advance.

[0036] like Figure 1 As shown, the cooling water flow control device is configured to supply a portion of the cooling water exhausted from the engine 1 when the engine is started to the cooling water outlet 21 of the exhaust gas recirculation cooler 2 (hereinafter referred to as "exhaust gas recirculation cooler outlet").

[0037] like Figure 1 As shown, the cooling system of the vehicle may use a water pump 3 to circulate cooling water to the engine 1 and the exhaust gas recirculation cooler 2 .

[0038] The exhaust gas recirculation cooler outlet 21 is directly connected to the cooling water inlet 31 (hereinafter referred to as "pump inlet") of the water pump 3, and no separate component is arranged between them. That is, the exhaust gas recirculation cooler outlet 21 and the pump inlet 31 are directly connected to each other through the cooling water flow path arranged between them.

[0039] The cooling water outlet 122 of the engine 1 (hereinafter referred to as "engine outlet") is connected to the pump inlet 31 through the thermal management module (TMM) 4 and the thermal control device. Therefore, when the engine 1 is started, the cooling water discharged from the engine 1 reaches the pump inlet 31 relatively later than the cooling water discharged from the exhaust gas recirculation cooler 2.

[0040] That is, when the engine 1 is started, the cooling water discharged from the exhaust gas recirculation cooler outlet 21 reaches the pump inlet 31 relatively earlier than the cooling water discharged from the engine outlet 122 .

[0041] The cooling water flow control device is configured so that, when the engine is started, a portion of the cooling water (hereinafter referred to as "initial cooling water") discharged from the inside of the engine 1 flows to the rear end of the exhaust gas recirculation cooler outlet 21 (i.e., downstream of the exhaust gas recirculation cooler outlet). As a result, the heating time of the cooling water flowing into the exhaust gas recirculation cooler 2 is shortened.

[0042] That is, since the cooling water flow control device can shorten the heating time of the cooling water discharged from the exhaust gas recirculation cooler 2 by using the initial cooling water, which has a relatively higher temperature than the temperature of the cooling water discharged from the exhaust gas recirculation cooler 2, the exhaust gas recirculation cooler 2 can be used in advance without any problems such as the problem of condensed water generation when the engine is started in the related art, and thus the fuel economy improvement effect according to the operation of the exhaust gas recirculation cooler 2 can be ensured.

[0043] In such Figure 1 In the exhaust gas recirculation cooler 2 shown, cooling water is continuously circulated from the initial start-up of the engine 1, and the temperature of the cooling water circulating in the exhaust gas recirculation cooler 2 is lower than the temperature of the initial cooling water discharged from the inside of the engine 1. In addition, the flow rate of the cooling water of the exhaust gas recirculation cooler 2 is controlled only by the engine RPM (revolutions per minute).

[0044] Since the initial cooling water exhausted from the inside of the engine 1 is supplied to the downstream side of the exhaust gas recirculation cooler outlet 21, the heating time of the cooling water circulating in the exhaust gas recirculation cooler 2 can be shortened.

[0045] exist Figure 1 , reference numeral “5” indicates a straight flow path 5. The straight flow path 5 is configured so that a portion of the initial cooling water exhausted from the engine 1 flows downstream of the exhaust gas recirculation cooler outlet 21. The remaining portion of the initial cooling water can flow to the thermal management module 4 through the engine outlet 122.

[0046] The straight flow path 5 is a flow path connecting between the vent hole 111 of the engine 1 and the exhaust gas recirculation cooler outlet 21. The straight flow path 5 is arranged between the vent hole 111 and the exhaust gas recirculation cooler outlet 21 so that the cooling water discharged through the vent hole 111 flows to the downstream side of the exhaust gas recirculation cooler outlet 21.

[0047] The straight flow path 5 can make the initial cooling water flow directly to the pump inlet 31 without passing through the thermal management module 4 and the thermal control device of the engine 1, and thus can shorten the flow path of the initial cooling water to the pump inlet 31. That is, the flow path of the initial cooling water can be shortened through the straight flow path 5, and the initial cooling water can flow directly to the pump inlet 31 through the straight flow path 5.

[0048] The vent hole 111 is used to discharge cooling water of the engine 1 and is provided on the engine 1 separately from the engine outlet 122. Figure 2As shown, the vent hole 111 may be processed and arranged on the engine head 11, and the engine outlet 122 may be arranged on the engine block 12. The vent hole 111 allows the cooling water (i.e., initial cooling water) held in the cooling water flow path (i.e., water jacket) inside the engine 1 when the engine 1 is started to flow to the downstream of the exhaust gas recirculation cooler outlet 21 through the straight flow path 5 when the engine is subsequently started. That is, the vent hole 111 may be interlocked with the water jacket 13, and the initial cooling water held in the water jacket 13 may be discharged toward the straight flow path 5.

[0049] When the engine 1 is started, the cooling water remaining in the water jacket 13 is discharged from the engine 1 by the water pump 3 through the engine outlet 122 and the vent hole 111. When the water pump 3 is driven, the initial cooling water stored in the water jacket 13 can be discharged from the water jacket 13.

[0050] The water jacket 13 is provided on the engine head 11, and covers the engine block 12 and the combustion chamber of the engine block 12 (refer to Figure 2 ). The water jacket 13 is arranged outside the combustion chamber and is formed to surround each combustion chamber. The water jacket 13 is provided with a cooling water inlet (hereinafter referred to as "engine inlet") 121 for inflow of cooling water and an engine outlet 122. In this case, the engine inlet 121 and the engine outlet 122 are provided on the engine block 12.

[0051] In addition, if Figure 2 As shown, a flow control valve 51 may be installed on the through flow path 5. The flow control valve 51 is configured to open and close the through flow path 5, and to control the flow and flow rate of cooling water in the through flow path 5. The flow control valve 51 may control the flow of cooling water from the vent hole 111 to the exhaust gas recirculation cooler outlet 21. The flow control valve 51 is a one-way valve that only allows cooling water to flow from the vent hole 111 to the exhaust gas recirculation cooler outlet 21. The opening of the flow control valve 51 may be controlled by a controller 6 disposed in the vehicle. The controller 6 may be an engine controller that controls an engine system of the vehicle.

[0052] The flow control valve 51 may be operated to open by the controller 6 when the engine is started to open the through flow path 5. That is, if the start of the engine 1 is detected, the controller 6 may open the flow control valve 51 to allow the initial cooling water to flow in the through flow path 5.

[0053] In addition, the controller 6 may control the opening and closing of the flow control valve 51 according to the ambient temperature when the engine is started.

[0054] In one form, if the ambient temperature is equal to or higher than the first predetermined temperature T1, the controller 6 may open the flow control valve 51 (refer to Figure 3 ). The ambient temperature may be detected by an ambient temperature sensor installed on the vehicle.

[0055] If the exhaust gas cooled by the exhaust gas recirculation cooler 2 (i.e., exhaust gas recirculation gas) is supplied to the engine 1 in a state where the ambient temperature is low, condensed water is generated in the intake system of the engine 1. The intake system is provided with a sensor for detecting the intake pressure, and if condensed water is generated on the sensor and freezes, the sensor cannot detect the intake pressure.

[0056] To cope with this, the controller 6 may suppress or prevent a large amount of condensed water from being generated in the intake system of the engine 1 by opening the flow control valve 51 only when the ambient temperature is equal to or higher than the first temperature T1.

[0057] That is, if the ambient temperature detected at the time of engine startup is lower than the first temperature T1, the controller 6 may operate the flow control valve 51 in the closed mode (refer to Figure 3 ).

[0058] If the flow control valve 51 is operated to be open, the initial cooling water of the engine can flow from the vent hole 111 to the exhaust gas recirculation cooler outlet 21 through the straight flow path 5, and if the flow control valve 51 is operated to be closed, the flow of cooling water through the straight flow path 5 is blocked. If the cooling water through the straight flow path 5 is blocked by the flow control valve 51, the initial cooling water discharged from the vent hole 111 will not flow to the exhaust gas recirculation cooler outlet 21.

[0059] like Figure 2 As shown, the thermal management module 4 is connected to the engine outlet 122, and the thermal management module 4 can be controlled according to the cooling water temperature and the ambient temperature. The thermal management module 4 can be configured downstream of the engine outlet 122 to perform thermal management on the cooling water circulating in the engine. The thermal management module 4 can perform thermal management of the cooling water using a plurality of valve components 41, 42 and 43 and a thermal control device configured downstream of the thermal management module 4. The thermal control device can be composed of a radiator 44, a heater 45 and an automatic transmission fluid cooler 46 configured downstream of the engine outlet 122.

[0060] The thermal management module 4 may be configured to include a plurality of valve members 41, 42, and 43 capable of controlling the flow of cooling water discharged from the engine outlet 122. The plurality of valve members 41, 42, and 43 may be first, second, and third valve members 41, 42, and 43.

[0061] The first valve member 41 may be installed in a flow path connecting between the engine outlet 122 and the radiator 44. That is, the first valve member 41 may be disposed upstream of the radiator 44 to control a flow rate of cooling water flowing from the engine outlet 122 to the radiator 44.

[0062] The second valve member 42 may be installed in a flow path connecting between the engine outlet 122 and the heater 45. That is, the second valve member 42 may be disposed upstream of the heater 45 to control a flow rate of cooling water flowing from the engine outlet 122 to the heater 45.

[0063] The third valve member 43 may be installed in a flow path connecting between the engine outlet 122 and the automatic transmission fluid cooler 46. That is, the third valve member 43 may be disposed upstream of the automatic transmission fluid cooler 46 to control the flow rate of cooling water flowing from the engine outlet 122 to the automatic transmission fluid cooler 46.

[0064] The valve members 41, 42, and 43 may receive a control signal sent from the controller 6, and their opening degrees may be controlled. The controller 6 may control the opening and closing operations of the valve members 41, 42, and 43 according to the cooling water temperature and the ambient temperature. That is, the thermal management module 4 may control the operation of the valve members 41, 42, and 43 based on the cooling water temperature and the ambient temperature. The temperature of the cooling water may be detected by a water temperature sensor (WTS) to be transmitted to the controller 6.

[0065] The water temperature sensor may be installed in the intake system of the engine to measure the temperature of the cooling water flowing into the engine 1 , or may be installed in the cooling water flow path between the engine outlet 122 and the thermal management module 4 to detect the temperature of the cooling water discharged from the engine outlet 122 .

[0066] The controller 6 can control the flow of cooling water discharged from the engine outlet 122 by controlling the opening and closing operations of the valve members 41, 42 and 43. The controller 6 can stop the flow of cooling water circulating in the engine by closing all the first to third valve members 41, 42 and 43.

[0067] Furthermore, the controller 6 may discharge the cooling water from the engine outlet 122 to the engine inlet 121 by opening one or two or more valve members selected from the first to third valve members 41 , 42 , and 43 .

[0068] The cooling water flowing to the radiator 44 may be cooled while passing through the radiator 44, and then may flow to the engine outlet 122. The cooling water flowing to the heater 45 may be heated by the heater 45, and then may flow to the engine outlet 122. In addition, the cooling water flowing to the automatic transmission fluid cooler 46 may be heated by heat exchange with the automatic transmission fluid (AFT). The automatic transmission fluid cooler 46 may be a heat exchanger configured to cool the automatic transmission fluid using the cooling water.

[0069] A water pump 3 is arranged downstream of the radiator 44, the heater 45, and the automatic transmission fluid cooler 46. The water pump 3 may be driven whenever the engine is started. If the cooling water flowing to the engine outlet 122 is blocked by the thermal management module 4 when the driving of the water pump 3 is started, the cooling water may circulate only in the exhaust gas recirculation cooler 2 and not in the engine 1.

[0070] Here, reference Figures 3 to 5 , the cooling water flow control method during engine startup will be described in more detail.

[0071] like Figure 3 If the ambient temperature is lower than the first temperature T1 at engine startup, the controller 6 operates the EGR valve 22 in the closed mode.

[0072] like Figure 4 As shown, the exhaust gas recirculation cooler 2 cools the exhaust gas exhausted from the engine 1 and recirculated to the intake system 7 of the engine, and the exhaust gas (e.g., exhaust gas recirculation gas) cooled by the exhaust gas recirculation cooler 2 can pass through the exhaust gas recirculation valve 22 and can flow to the intake system 7 of the engine. In this case, the flow rate of the exhaust gas recirculation gas supplied by the exhaust gas recirculation valve 22 to the intake system 7 of the engine can be controlled.

[0073] The first temperature T1 may be configured as a temperature value at which there is a concern that a large amount of condensed water may be generated and frozen in the intake system 7 of the engine due to a low ambient temperature. For example, the first temperature T1 may be 10° C. If the temperature of the environment (i.e., intake air) supplied to the engine 1 is lower than the first temperature T1, a large amount of condensed water may be generated and frozen in the intake system 7 of the engine due to a temperature difference between the intake air and the exhaust gas (i.e., exhaust gas recirculation gas) supplied to the intake system 7 of the engine through the exhaust gas recirculation valve 22.

[0074] More specifically, in the intake manifold of the intake system 7 of the engine, condensed water may be generated by the exhaust gas recirculation gas recirculated to the intake system 7 of the engine through the exhaust gas recirculation cooler 2. If the ambient temperature is lower than the first temperature T1, a large amount of condensed water is generated and frozen in the intake manifold due to the temperature difference between the exhaust gas recirculation gas and the intake air, and thus the intake pressure sensor mounted on the intake manifold is frozen, causing the intake pressure sensor to fail to operate normally.

[0075] Therefore, if the ambient temperature is lower than the first temperature T1, the controller 6 may not operate the exhaust gas recirculation cooler 2 to suppress or prevent the intake pressure sensor from being frozen, and if the exhaust gas recirculation cooler 2 is not operated, it is not necessary to heat the cooling water supplied to the exhaust gas recirculation cooler 2, and therefore the flow control valve 51 operates in a closed mode.

[0076] Furthermore, if the ambient temperature is lower than the first temperature T1 and the heater 45 is in operation when the engine is started, the controller 6 blocks the initial cooling water from flowing to the direct flow path 5 by closing the flow control valve 51 , and simultaneously allows the initial cooling water to flow to the heater 45 by opening the second valve member 42 .

[0077] In other words, if the heater 45 operates in a state where the ambient temperature at the time of engine startup is lower than the first temperature T1, the controller 6 can close the flow control valve 51 while opening the second valve member 42. In this case, the initial cooling water discharged from the engine 1 through the engine outlet 122 can flow to the heater 45, be heated by the heater 45, and then flow to the pump inlet 31. The initial cooling water heated by the heater 45 can flow to the engine inlet 121 through the water pump 3, and thus the heating time of the cooling water can be greatly shortened.

[0078] In one form, such as Figure 5 After the heating of the cooling water is completed, if the cooling water temperature detected during the vehicle running is equal to or higher than the third predetermined temperature T3, the controller 6 closes the flow control valve 51.

[0079] If the cooling water is heated by the engine 1 and the exhaust gas recirculation cooler 2 during driving, and the temperature of the cooling water becomes equal to or higher than the third temperature T3, the heat transfer rate (i.e., the amount of heat transfer) of the exhaust gas recirculation cooler 2 is reduced to a very low level (e.g., about 5%). Here, the third temperature T3 may be, for example, 110°C.

[0080] If the heat transfer rate of the EGR cooler 2 decreases to a very low level, it may be determined that the operation of the EGR cooler 2 is unnecessary, and if the operation of the EGR cooler 2 is unnecessary, the through flow path 5 does not need to be opened.

[0081] Therefore, if the cooling water temperature of the exhaust gas recirculation cooler 2 rises above the third temperature T3, the controller 6 stops the operation of the exhaust gas recirculation cooler 2 and operates the flow control valve 51 in a closed mode to prevent the cooling water from flowing to the exhaust gas recirculation cooler 2 through the straight flow path 5.

[0082] In addition, if the valve components 41, 42 and 43 of the thermal management module 4 are all stuck so that the cooling water cannot flow through the thermal management module 4, the controller 6 still operates the flow control valve 51 in the open mode even though the cooling water temperature is equal to or higher than the third temperature T3, and thus the engine 1 can be prevented from overheating due to the circulation of cooling water.

[0083] Figure 6 3 is a graph of experimental results, showing the effect of shortening the heating time of the cooling water by heating the cooling water using the straight flow path 5 .

[0084] like Figure 6 As shown, if the initial cooling water of the engine flows to the exhaust gas recirculation cooler outlet 21 through the straight flow path 5, the heating time of the cooling water on the exhaust gas recirculation cooler 2 side can be shortened, and a high cooling water temperature can be maintained in the initial stage after heating, compared with the case where the straight flow path 5 is not used. If a high cooling water temperature is maintained in the initial stage after heating, the friction loss of the engine is reduced, and thus the fuel economy can be improved.

[0085] The present disclosure has been described in detail with reference to its exemplary forms. However, it will be appreciated by those skilled in the art that these forms may be changed without departing from the principles and spirit of the present disclosure.

Claims

1. A cooling water flow control device for a cooling system of a vehicle, comprising: an exhaust gas recirculation cooler configured to cool exhaust gas supplied to an intake system of an engine using cooling water and comprising an exhaust gas recirculation cooler outlet through which the cooling water is discharged, wherein the engine is provided with an engine outlet and an air vent for discharging the cooling water; a water pump configured to circulate the cooling water to the exhaust gas recirculation cooler and the engine when the engine is started; and The straight-through flow path is configured to guide the cooling water from the vent to the downstream side of the exhaust gas recirculation cooler outlet, wherein the vent is arranged on the engine head, the engine outlet is arranged on the engine block, the vent is connected to the straight-through flow path, and the engine outlet is connected to a thermal management module, and the thermal management module is installed downstream of the engine outlet to perform thermal management of the cooling water.

2. The cooling water flow control device according to claim 1, further comprising: A flow control valve is configured to open and close the through-flow path, wherein the flow control valve is installed on the through-flow path and is configured to operate in an open mode when the engine is started.

3. The cooling water flow control device according to claim 2, wherein: When the ambient temperature when the engine is started is lower than a first predetermined temperature, the flow control valve is closed.

4. The cooling water flow control device according to claim 3, wherein: When the ambient temperature when the engine is started is equal to or higher than the first predetermined temperature, the flow control valve is opened.

5. The cooling water flow control device according to claim 3, further comprising: the thermal management module configured to perform thermal management of the cooling water and mounted on the downstream side of the engine outlet, The cooling water discharged from the engine outlet flows to the water pump through the thermal management module.

6. The cooling water flow control device according to claim 5, wherein: The thermal management module comprises: a first valve member mounted between the engine outlet and the radiator; a second valve member mounted between the engine outlet and the heater; and A third valve member is installed between the engine outlet and the automatic transmission fluid cooler.

7. The cooling water flow control device according to claim 6, wherein: The flow control valve is controlled by a controller, and When the ambient temperature at the time of engine startup is lower than the first predetermined temperature and the heater is in operation, the controller is configured to close the flow control valve and open the second valve member so that the cooling water exhausted from the engine flows to the heater.

8. The cooling water flow control device according to claim 7, wherein: When the temperature of the cooling water of the EGR cooler is equal to or higher than a third predetermined temperature, the controller is configured to stop the operation of the EGR cooler and operate the flow control valve in a closing mode.

9. The cooling water flow control device according to claim 8, wherein: When at least one of the first valve member, the second valve member, and the third valve member of the thermal management module is stuck during driving, the controller is configured to control the flow control valve to open.

10. The cooling water flow control device according to claim 2, wherein: The flow control valve is a non-return valve that allows cooling water to flow from the breather to the exhaust gas recirculation cooler outlet only when the engine is started.

Images