WO2023024994A1

WO2023024994A1 - Engine cooling system and vehicle

Info

Publication number: WO2023024994A1
Application number: PCT/CN2022/112961
Authority: WO
Inventors: 胡文波
Original assignee: 中国第一汽车股份有限公司
Priority date: 2021-08-25
Filing date: 2022-08-17
Publication date: 2023-03-02
Also published as: CN113530635A; CN113530635B

Abstract

An engine cooling system. An engine comprises a lubricating oil circuit, an exhaust gas pipeline and an inner cooling pipeline, which is configured to reduce the internal temperature of the engine. The engine cooling system comprises: a lubricating oil cooling unit (1), which is arranged on the lubricating oil circuit; an EGR cooling unit (2), which is arranged on the exhaust gas pipeline, wherein a cooling cavity of the EGR cooling unit is in communication with the inner cooling pipeline; a temperature measurement unit (10), which is configured to measure the temperature of lubricating oil in the lubricating oil circuit; and a control unit (11), which is electrically connected to the temperature measurement unit, wherein when the temperature of the lubricating oil is less than a first temperature threshold value, the control unit controls the enabling of the circulation in the inner cooling pipeline, the EGR cooling unit and the lubricating oil cooling unit, so as to form a warm-up loop; and when the temperature of the lubricating oil is greater than the first temperature threshold value, the control unit controls the enabling of the circulation in the inner cooling pipeline and the lubricating oil cooling unit, so as to form a lubricating oil cooling loop, and controls the enabling of the circulation in the inner cooling pipeline and the EGR cooling unit, so as to form an exhaust gas cooling loop. The engine cooling system can achieve a rapid temperature rise of lubricating oil and a high warm-up speed, can effectively reduce the fuel consumption of an engine, and can make full use of the performance of an EGR cooler. Further provided is a vehicle.

Description

Engine cooling system and automobile

This application claims the priority of the Chinese patent application with application number 202110979432.1 submitted to the China Patent Office on August 25, 2021, the entire content of which is incorporated in this application by reference.

technical field

The present application relates to the technical field of vehicle engineering, for example, to an engine cooling system and an automobile.

Background technique

The exhaust gas recirculation (Exhaust Gas Re-circulation, EGR) system returns part of the exhaust gas in the exhaust pipe to the intake manifold of the engine, and reintroduces it into the combustion chamber of the engine together with the fresh mixed gas, so as to reduce the tendency of high-load knocking and Reduce the mechanical loss of the engine during the intake and exhaust process (that is, the pumping loss), and at the same time reduce the emission of nitrogen oxides, and improve the reliability and economy of the engine. The EGR system includes an EGR valve, an EGR cooler and related pipelines, etc., wherein the function of the EGR cooler is to reduce the temperature of the exhaust gas in the EGR system by introducing coolant. During this heat exchange process, the heat of the exhaust gas is transferred to the cooling liquid, ie the temperature of the cooling liquid increases and the temperature of the exhaust gas decreases.

Most of the EGR coolers pass into the coolant from the water outlet of the engine's internal cooling circuit. After the coolant exchanges heat with the exhaust gas in the EGR system, it flows back to the water inlet of the engine's internal cooling circuit to form a fixed cooling circuit with constant flow of water. Although this form of cooling circuit can use the heat of the exhaust gas to increase the overall temperature of the engine coolant to a certain extent and increase the warm-up speed, the proportion of the coolant flow through the EGR cooler to the entire engine coolant flow is not high. The speed of coolant temperature increase is limited, the improvement to reduce engine fuel consumption is not obvious, and the EGR cooler is not fully utilized.

Contents of the invention

The application provides an engine cooling system and an automobile. When the engine is initially started, the temperature of the lubricating oil can be quickly raised, the warm-up speed is fast, the engine oil consumption can be effectively reduced, and the performance of the EGR cooler can be fully utilized.

This application adopts the following technical solutions:

The present application provides an engine cooling system, the engine includes a lubricating oil circuit, an exhaust gas pipeline, and an internal cooling pipeline configured to reduce the internal temperature of the engine, and the engine cooling system includes:

A lubricating oil cooling unit is arranged on the lubricating oil road;

The exhaust gas recirculation EGR cooling unit is arranged on the exhaust gas pipeline, and the cooling chamber of the EGR cooling unit communicates with the internal cooling pipeline so that the heat exchange fluid flowing out of the liquid outlet of the internal cooling pipeline heat exchange with the exhaust gas in the exhaust gas pipeline;

a temperature measuring unit configured to measure the temperature of the lubricating oil in the lubricating oil circuit;

a control unit electrically connected to the temperature measurement unit;

When the temperature of the lubricating oil measured by the temperature measurement unit is lower than the first temperature threshold, the control unit controls the internal cooling pipeline, the EGR cooling unit and the lubricating oil cooling unit to be in circulation, so as to Form a warm-up circuit;

When the temperature of the lubricating oil measured by the temperature measuring unit is greater than the first temperature threshold, the control unit controls the internal cooling pipeline and the lubricating oil cooling unit to be circulated to form lubricating oil cooling. circuit, and control the circulation of the internal cooling pipeline and the EGR cooling unit to form an exhaust gas cooling circuit.

Optionally, a temperature-sensing valve and a heat dissipation unit are also included, and when the temperature of the heat exchange fluid is greater than a second temperature threshold, the temperature-sensing valve is opened, so that the heat dissipation unit is in circulation with the internal cooling pipeline , the opening of the temperature-sensing valve increases as the temperature of the heat exchange fluid increases.

Optionally, a first liquid infusion pump is arranged upstream of the internal cooling pipeline, and the liquid inlet of the first liquid infusion pump is set to be connected to the cooling cavity of the lubricating oil cooling unit and the cooling cavity of the EGR cooling unit. connected.

Optionally, a heating unit is also included, the control unit is configured to be electrically connected to a heating switch, and when the heating switch is turned on, the control unit controls the internal cooling pipeline, the EGR cooling unit and the heating unit Loop conduction to form a heating circuit.

Optionally, a second infusion pump is provided upstream of the heating unit, and a liquid inlet of the second infusion pump is configured to communicate with the cooling cavity of the EGR cooling unit.

Optionally, the first infusion pump is a mechanical water pump or an electronic water pump, and the second infusion pump is an electronic water pump.

Optionally, a three-way valve is provided downstream of the internal cooling pipeline, the first outlet of the three-way valve is set to communicate with the cooling chamber of the lubricating oil cooling unit, and the second outlet of the three-way valve is set to To communicate with the cooling cavity of the EGR cooling unit.

Optionally, a four-way valve is arranged downstream of the EGR cooling unit, the first outlet of the four-way valve is set to communicate with the cooling chamber of the lubricating oil cooling unit, and the second outlet of the four-way valve is set to In order to communicate with the inner cooling pipeline, the third outlet of the four-way valve is set to communicate with the heating cavity of the heating unit.

Optionally, the three-way valve is a three-way solenoid valve, the four-way valve is a four-way solenoid valve, and the control unit is electrically connected to the three-way solenoid valve and the four-way solenoid valve;

When the temperature of the lubricating oil is lower than the first temperature threshold, the control unit controls the opening of the second outlet of the three-way solenoid valve, controls the closing of the first outlet of the three-way solenoid valve, and controls the opening of the four-way solenoid valve. The first outlet of the electromagnetic valve is opened, and the second outlet and the third outlet of the four-way electromagnetic valve are controlled to be closed, so as to conduct the warm-up circuit;

When the temperature of the lubricating oil is greater than the first temperature threshold, the control unit controls the opening of the first outlet and the second outlet of the three-way solenoid valve, controls the opening of the second outlet of the four-way solenoid valve, and controlling the first outlet and the third outlet of the four-way solenoid valve to be closed, so as to conduct the lubricating oil cooling circuit and the exhaust gas cooling circuit;

When the heating switch is turned on, the control unit controls the opening of the third outlet of the four-way solenoid valve, and controls the closing of the first outlet and the second outlet of the four-way solenoid valve to conduct the heating circuit, And close the exhaust gas cooling circuit.

The present application provides an automobile, including the above-mentioned engine cooling system.

Description of drawings

Fig. 1 is the structural representation of the engine cooling system that the application provides;

Fig. 2 is a schematic diagram of the flow of the heat exchange fluid when the warm-up circuit is turned on in the engine cooling system provided by the present application;

Fig. 3 is a flow schematic diagram of the heat exchange fluid when the lubricating oil cooling circuit and the exhaust gas cooling circuit are connected in the engine cooling system provided by the present application;

Fig. 4 is a schematic diagram of the flow of the heat exchange fluid when the heating circuit is turned on in the engine cooling system provided by the present application.

In the picture:

100 - engine;

1-lubricating oil cooling unit; 2-EGR cooling unit; 3-temperature sensing valve; 4-radiation unit; 5-first infusion pump; 6-heating unit; 7-second infusion pump; 8-three-way valve; 9 - four-way valve, 10 - temperature measuring unit, 11 - control unit.

Detailed ways

The application will be described below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the present application, but not to limit the present application. In addition, it should be noted that the drawings only show some structures related to the present application but not all structures.

In the description of this application, unless otherwise clearly specified and limited, the terms "connected", "connected" and "fixed" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integrated ; It can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediary, and it can be the internal communication of two components or the interaction relationship between two components. Those of ordinary skill in the art can understand the specific meanings of the above terms in this application depending on the specific circumstances.

In this application, unless otherwise expressly specified and limited, a first feature being "on" or "under" a second feature may include direct contact between the first and second features, and may also include the first and second features Not in direct contact but through another characteristic contact between them. Moreover, "above", "above" and "above" the first feature on the second feature include that the first feature is directly above and obliquely above the second feature, or simply means that the first feature is horizontally higher than the second feature. "Below", "beneath" and "under" the first feature to the second feature include that the first feature is directly below and obliquely below the second feature, or simply means that the first feature has a lower level than the second feature.

In the description of this embodiment, the terms "up", "down", "left", "right" and other orientations or positional relationships are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of description and simplification of operations. It is not intended to indicate or imply that the device or element referred to must have a particular orientation, be constructed, or operate in a particular orientation, and thus should not be construed as limiting the application. In addition, the terms "first" and "second" are only used to distinguish in description, and have no special meaning.

As shown in Figure 1, this embodiment provides an engine cooling system, which can realize the rapid warm-up of the engine 100 and ensure the cooling effect of the engine 100 after the smooth movement. The exhaust gas can also be fully utilized to improve the fuel consumption of the engine 100 . Wherein, the engine 100 includes a lubricating oil circuit configured to provide lubrication for the movement of internal parts, an exhaust gas pipeline configured to guide exhaust gas generated after fuel combustion, and an internal cooling pipeline configured to reduce the internal temperature of the engine 100 . The engine cooling system includes a lubricating oil cooling unit 1 , an EGR cooling unit 2 , a temperature measuring unit 10 and a control unit 11 .

The heat exchange fluid circulates inside and outside the engine 100 . For example, the internal cooling circuit inside the engine 100 has a liquid outlet and a liquid inlet, and the heat exchange fluid flows out through the liquid outlet of the internal cooling circuit, flows outside the engine 100, and flows through one or more external mechanisms. (such as lubricating oil cooling unit 1 or EGR cooling unit 2, etc.), then return to the inner cooling pipeline through the liquid inlet of the inner cooling pipeline.

The lubricating oil cooling unit 1 is arranged on the lubricating oil road, and the cooling cavity of the lubricating oil cooling unit 1 can communicate with the inner cooling pipeline, so that the heat exchange fluid flowing out of the inner cooling pipeline can exchange heat with the lubricating oil.

The EGR cooling unit 2 is arranged on the exhaust gas pipeline. The EGR cooling unit 2 of the engine 100 using the EGR system can be divided into two types: the first type is integrated, the EGR cooling unit 2 is integrated in the engine cooling system, and is directly taken from the liquid outlet of the internal cooling pipeline of the engine 100. The heat exchange fluid output from the EGR cooling unit 2 returns to the liquid inlet of the internal cooling pipeline. In this scheme, the cooling circuit of the EGR cooling unit 2 is normally open and does not perform switching control, and cannot be used for heating lubricating oil or For warm air intake; the second type is independent, EGR cooling unit 2 adopts an independent low-temperature cooling system, including independent low-temperature radiators, electric water pumps and related pipelines, and the heat exchange fluid in this system does not cool with the engine The heat exchange fluid of the system is mixed. This solution is beneficial to the heat dissipation of the EGR system, but the engine 100 cannot use the heat generated by the EGR system to achieve a rapid warm-up effect.

In this embodiment, the cooling chamber of the EGR cooling unit 2 can communicate with the internal cooling pipeline, so that the heat exchange fluid flowing out from the liquid outlet of the internal cooling pipeline can exchange heat with the exhaust gas in the exhaust gas pipeline, so as to Reduce the temperature of the exhaust gas and increase the temperature of the heat exchange fluid to achieve rapid warm-up.

Warming up can make the engine 100 reach the optimal operating condition, which is beneficial to improve the service life of the engine 100 . After the warm-up process is over, it is necessary to cool down the lubricating oil in the lubricating oil circuit to prevent the oil temperature from being too high and reduce the lubricating effect, and avoid greater wear of internal parts. The switching between the warm-up process and the subsequent process of lowering the oil temperature is realized through the temperature measuring unit 10 and the control unit 11 which are electrically connected. The temperature measuring unit 10 can measure the temperature of the lubricating oil in the lubricating oil circuit, and the control unit 11 switches between the warm-up process and the subsequent cooling process according to the received temperature information measured by the temperature measuring unit 10 . When the lubricating oil temperature measured by the temperature measuring unit 10 is lower than the first temperature threshold, the control unit 11 controls the internal cooling pipeline, the EGR cooling unit 2 and the lubricating oil cooling unit 1 to be circulated to form a warm-up circuit. When the temperature of the lubricating oil measured by the temperature measuring unit 10 is greater than the first temperature threshold, the control unit 11 controls the internal cooling pipeline and the lubricating oil cooling unit 1 to be circulated to form a lubricating oil cooling circuit, and controls the internal cooling pipeline and the EGR cooling unit 2 are circulated to form an exhaust gas cooling circuit.

Exemplarily, when the engine 100 is initially started, the lubricating oil temperature in the lubricating oil circuit is lower than the first temperature threshold, and the control unit 11 turns on the warm-up circuit. Referring to FIG. 2 , the heat exchange fluid in the internal cooling pipeline flows out through the liquid outlet and enters the cooling cavity of the EGR cooling unit 2 . The heat exchange fluid exchanges heat with the exhaust gas in the exhaust gas pipeline in the cooling chamber. After the fuel is burned in the cylinder of the engine 100, the temperature of the exhaust gas discharged is relatively high. After the heat exchange, the temperature of the exhaust gas decreases, while the temperature of the heat exchange fluid raised. The heated heat exchange fluid continues to flow into the cooling chamber of the lubricating oil cooling unit 1, and exchanges heat with the lubricating oil in the lubricating oil passage, so that the temperature of the lubricating oil increases, thereby reducing the viscosity of the lubricating oil, and making the engine 100 The parts are lubricated better, the working condition is optimal, and the oil consumption of the whole machine is improved. When the warm-up circuit is turned on, except for a small part of the heat exchange fluid flowing through the degassing cycle, most of the heat exchange fluid circulates through the warm-up circuit to make full use of the heat of the exhaust gas to heat the lubricating oil and quickly increase the temperature of the lubricating oil, thus making the engine 100 Reach optimal conditions quickly.

When the temperature of the lubricating oil gradually rises above the first temperature threshold, the control unit 11 controls the warm-up circuit to be closed, and the lubricating oil cooling circuit and the exhaust gas cooling circuit to be opened. Referring to Figure 3, part of the heat exchange fluid flowing out of the liquid outlet of the internal cooling pipeline enters the cooling chamber of the lubricating oil cooling unit 1 to cool down the lubricating oil with a high temperature in the lubricating oil circuit and prevent the lubricating oil from being too thin and causing Insufficient lubrication. Another part of the heat exchange fluid enters the cooling chamber of the EGR cooling unit 2 to cool the high-temperature exhaust gas in the exhaust gas pipeline. The mechanical loss generated by the intake and exhaust process can also reduce the emission of nitrogen oxides, and improve the reliability and economy of the engine 100 .

The first temperature threshold may be determined according to the optimal lubricating state of the lubricating oil. Exemplarily, in this embodiment, the first temperature threshold is 95 degrees Celsius, that is, when the lubricating oil temperature is higher than 95 degrees Celsius, the warm-up circuit can be closed, and the lubricating oil cooling circuit and the exhaust gas cooling circuit can be turned on.

Optionally, the engine cooling system further includes a temperature sensing valve 3 and a cooling unit 4 . When the temperature of the heat exchange fluid is greater than the second temperature threshold, the temperature-sensing valve 3 is opened, so that the cooling unit 4 is in circulation with the internal cooling pipeline. When the temperature of the heat exchange fluid is too high, the heat exchange fluid cannot effectively cool down the lubricating oil in the lubricating oil circuit and the exhaust gas in the exhaust gas pipeline, which will lead to an increase in the temperature of the lubricating oil, a decrease in the lubrication effect, and re- The temperature of the exhaust gas entering the combustion chamber of the engine 100 is high, and the emission of nitrogen oxides cannot be suppressed. Therefore, a second temperature threshold is set, and when the temperature sensing valve 3 senses that the temperature of the heat exchange fluid is greater than the second temperature threshold, it can be opened, so that part of the heat exchange fluid flowing out of the internal cooling pipeline passes through the temperature sensing valve 3 Enter the heat dissipation unit 4 to cool down the heat exchange fluid, and the cooled heat exchange fluid flows back into the internal cooling pipeline to reduce the overall temperature of the heat exchange fluid, thereby cooling lubricating oil and exhaust gas.

Optionally, the opening of the temperature-sensing valve 3 increases as the temperature of the heat exchange fluid increases. The higher the temperature of the heat exchange fluid, the greater the opening of the temperature sensing valve 3, so as to increase the flow rate of the heat exchange fluid through the temperature sensing valve 3, thereby increasing the cooling speed of the heat exchange fluid to achieve rapid cooling.

Optionally, the engine cooling system further includes a heating unit 6 . A heating switch is arranged in the cab of the automobile, and the heating switch is electrically connected with the control unit 11 . When there is a heating demand, turn on the heating switch, and the control unit 11 can control the circulation of the internal cooling pipeline, the EGR cooling unit 2 and the heating unit 6 to form a heating circuit. Figure 4 is a schematic diagram of the flow of the heat exchange fluid when the heating circuit is turned on. Part of the heat exchange fluid flowing out of the internal cooling pipeline of the engine 100 enters the cooling cavity of the lubricating oil cooling unit 1 to cool down the lubricating oil, and the other part of the heat exchange fluid enters the cooling cavity of the EGR cooling unit 2 to exchange heat with the exhaust gas. The high heat is transferred to the heat exchange fluid, and then the high temperature heat exchange fluid enters the heating unit 6, and the heating chamber of the heating unit 6 can absorb the heat of the high temperature heat exchange fluid to blow out hot air to achieve heating and improve the comfort of the cab.

It should be noted that when the heating circuit is turned on, the exhaust gas cooling circuit is closed, so that almost all the heat exchange fluid heated by the exhaust gas flows into the heating cavity of the heating unit 6 to fully utilize the heat of the exhaust gas.

Optionally, a first infusion pump 5 is arranged upstream of the internal cooling pipeline. The liquid inlet of the first infusion pump 5 can communicate with the cooling cavity of the lubricating oil cooling unit 1 and the cooling cavity of the EGR cooling unit 2 respectively. The first infusion pump 5 can provide power for the flow of the heat exchange fluid in multiple circuits, so that the heat exchange fluid can circulate rapidly, improve the warm-up efficiency, and increase the cooling speed of lubricating oil and exhaust gas.

Optionally, in this embodiment, the first infusion pump 5 may be a mechanical water pump, which is not affected by electromagnetic effects of the engine cooling system circuit. The first infusion pump 5 can also be an electronic water pump, and its flow rate can not be affected by the rotation speed of the engine 100 , and the operation is stable.

Optionally, a second infusion pump 7 is arranged upstream of the heating unit 6 , and the liquid inlet of the second infusion pump 7 can communicate with the cooling cavity of the EGR cooling unit 2 . The second infusion pump 7 can provide power for the heat exchange fluid in the heating circuit to ensure the reliability of heating.

Optionally, the second infusion pump 7 is an electronic water pump, and the flow rate of the second infusion pump 7 is not affected by the rotational speed of the engine 100 , and the operation is stable. Moreover, the power required in the heating circuit is relatively small, and the electromagnetic interference received by the electronic water pump is also small.

Optionally, referring to FIG. 1 , a three-way valve 8 is provided downstream of the internal cooling pipeline, and the first outlet of the three-way valve 8 can communicate with the cooling chamber of the lubricating oil cooling unit 1 to conduct the cooling of the lubricating oil cooling unit 1. Cavity and internal cooling pipeline. The second outlet of the three-way valve 8 can be communicated with the cooling cavity of the EGR cooling unit 2 to connect the cooling cavity of the EGR cooling unit 2 with the internal cooling pipeline.

Referring to Fig. 1, optionally, a four-way valve 9 is provided downstream of the EGR cooling unit 2, and the first outlet of the four-way valve 9 can be communicated with the cooling chamber of the lubricating oil cooling unit 1 to conduct cooling of the EGR cooling unit 2. The liquid outlet of the chamber and the liquid inlet of the cooling chamber of the lubricating oil cooling unit 1. The second outlet of the four-way valve 9 can communicate with the inner cavity of the first infusion pump 5 , so that the liquid outlet of the cooling chamber of the EGR cooling unit 2 communicates with the internal cooling pipeline through the first infusion pump 5 . The third outlet of the four-way valve 9 can be communicated with the heating chamber of the heating unit 6 through the second infusion pump 7 to connect the liquid outlet of the cooling chamber of the EGR cooling unit 2 with the liquid inlet of the heating chamber of the heating unit 6 .

Optionally, in this embodiment, the three-way valve 8 is a three-way solenoid valve, the four-way valve 9 is a four-way solenoid valve, and the control unit 11 is electrically connected to both the three-way solenoid valve and the four-way solenoid valve. The opening and closing of multiple outlets of the three-way solenoid valve and the four-way solenoid valve can be automatically controlled through the control unit 11, which is convenient and quick.

Referring to Fig. 2, when the engine 100 is initially started, the temperature of the lubricating oil measured by the temperature measuring unit 10 is lower than the first temperature threshold, and the control unit 11 controls the opening of the second outlet of the three-way solenoid valve according to this signal, and controls the three-way solenoid valve The first outlet of the four-way solenoid valve is closed, the first outlet of the four-way solenoid valve is opened, and the second and third outlets of the four-way solenoid valve are closed. At this time, the lubricating oil cooling unit 1 is connected in series with the EGR cooling unit 2 . The heat exchange fluid flowing out of the liquid outlet of the internal cooling pipeline of the engine 100 passes through the inlet of the three-way solenoid valve, the second outlet of the three-way solenoid valve, the EGR cooling unit 2, the inlet of the four-way solenoid valve, and the four-way solenoid valve. The first outlet of the valve and the lubricating oil cooling unit 1 are finally returned to the internal cooling pipeline through the first infusion pump 5, so as to conduct the warm-up circuit and increase the temperature of the lubricating oil, so that the engine 100 can quickly reach the best working state.

After the engine 100 starts for a period of time, the temperature of the lubricating oil continues to rise. When the temperature of the lubricating oil measured by the temperature measuring unit 10 rises above the first temperature threshold, the control unit 11 controls the first outlet and the second outlet of the three-way solenoid valve. The outlets are all open, and the second outlet controlling the four-way solenoid valve is open, and the first outlet and the third outlet controlling the four-way solenoid valve are both closed, see Figure 3, at this time, the lubricating oil cooling unit 1 and the EGR cooling unit 2 are connected in parallel . Part of the heat exchange fluid flowing out through the liquid outlet of the internal cooling pipeline of the engine 100 passes through the inlet of the three-way solenoid valve, the first outlet of the three-way solenoid valve, and the lubricating oil cooling unit 1 in sequence, and finally flows back through the first infusion pump 5 to the internal cooling pipeline, so that this part of the heat exchange fluid can circulate in the lubricating oil cooling circuit, reduce the temperature of the lubricating oil, and ensure a good lubricating effect of the components in the engine 100 . The other part of the heat exchange fluid passes through the inlet of the three-way solenoid valve, the second outlet of the three-way solenoid valve, the EGR cooling unit 2, the inlet of the four-way solenoid valve, and the second outlet of the four-way solenoid valve, and finally passes through the first infusion fluid The pump 5 returns to the internal cooling pipeline, and this part of the heat exchange fluid circulates in the exhaust gas cooling circuit to reduce the temperature of the exhaust gas reintroduced into the combustion chamber and reduce the emission of nitrogen oxides.

When the heating switch is turned on, the control unit 11 controls the opening of the third outlet of the four-way solenoid valve, and controls the closing of the first outlet and the second outlet of the four-way solenoid valve. Referring to FIG. 4 , at this time, the EGR cooling unit 2 is connected in series with the heating unit 6 and then connected in parallel with the lubricating oil cooling unit 1 . Part of the heat exchange fluid flowing out of the liquid outlet of the internal cooling pipeline of the engine 100 continues to circulate in the lubricating oil cooling circuit, and the other part flows through the inlet of the three-way solenoid valve, the second outlet of the three-way solenoid valve, and the EGR cooling circuit in sequence. Unit 2, the inlet of the four-way solenoid valve, the third outlet of the four-way solenoid valve, the second infusion pump 7 and the heating unit 6, and finally return to the internal cooling pipeline through the first infusion pump 5, and this part of the heat exchange fluid is circulation in the heating circuit. When switching to the heating circuit, the exhaust gas cooling circuit is automatically closed, so that after the heat of the high-temperature exhaust gas is transferred to the heat exchange fluid in the heating circuit, almost all the high-temperature heat exchange fluid flows into the heating cavity of the heating unit 6, improving the utilization rate of the exhaust gas .

This embodiment also provides an automobile, including the above-mentioned engine cooling system.

When the car is just started, the control unit 11 controls the warm-up circuit to conduct, and the heat exchange fluid heated by the exhaust gas can quickly increase the oil temperature of the lubricating oil, reduce the viscosity of the lubricating oil, and improve the fuel consumption of the engine 100 . After the car is started for a period of time, the oil temperature in the lubricating oil circuit rises. When the temperature of the lubricating oil exceeds the first temperature threshold, the control unit 11 starts the lubricating oil cooling circuit to cool down the lubricating oil. In this circuit, the heat exchange fluid does not pass through the The EGR cooling unit 2 conducts heat exchange with the exhaust gas, therefore, when the relatively low-temperature heat exchange fluid passes through the lubricating oil cooling unit 1 , the temperature of the lubricating oil can be reduced. At the same time, the control unit 11 controls the conduction of the exhaust gas cooling circuit, so that the lower temperature heat exchange fluid can exchange heat with the exhaust gas generated by the fuel in the combustion chamber of the engine 100 in the circuit, thereby reducing the temperature of the exhaust gas in the exhaust gas pipeline. Because the oxygen content in the exhaust gas discharged from the engine 100 is extremely low or even non-existent, the exhaust gas after cooling down and the gas inhaled by the engine 100 are relaxed and then introduced into the combustion chamber, the oxygen concentration in the mixed gas is reduced, and is lower than the oxygen content in the atmosphere. In contrast, its maximum temperature during combustion will be reduced, effectively inhibiting the generation of nitrogen oxides, which is beneficial to environmental protection. When the combustion temperature is lowered, the heat transfer between the cylinder of the engine 100 and the wall surface of the combustion chamber and the surface of the piston will be reduced, and the loss caused by thermal dissociation will also be slightly reduced, and the fuel economy will also be improved.

The cab of the car is provided with a heating switch. When the user needs heating, the heating switch is turned on, and the control unit 11 can control the exhaust gas cooling circuit to be closed, while the heating circuit is turned on (the lubricating oil cooling circuit is always on). The automobile can use the heat of the high-temperature exhaust gas to heat the heat exchange fluid passed into the heating unit 6 to obtain warm air, fully utilize the heat in the exhaust gas, and improve the utilization rate of fuel. When the heating circuit is turned on, the exhaust gas can still be cooled, and the exhaust gas reintroduced into the combustion chamber of the engine is always the cooled exhaust gas.

Claims

An engine cooling system, wherein the engine (100) includes a lubricating oil circuit, an exhaust gas pipeline, and an internal cooling circuit configured to reduce the internal temperature of the engine (100), and the engine cooling system includes:

Lubricating oil cooling unit (1), arranged on the lubricating oil road;

The exhaust gas recirculation EGR cooling unit (2) is arranged on the exhaust gas pipeline, and the cooling chamber of the EGR cooling unit (2) communicates with the internal cooling pipeline so that the liquid discharged from the internal cooling pipeline The heat exchange fluid flowing out of the port performs heat exchange with the exhaust gas in the exhaust gas pipeline;

a temperature measuring unit (10), configured to measure the temperature of the lubricating oil in the lubricating oil circuit;

a control unit (11), electrically connected to the temperature measuring unit (10);

When the temperature of the lubricating oil measured by the temperature measuring unit (10) is lower than the first temperature threshold, the control unit (11) controls the internal cooling pipeline, the EGR cooling unit (2) And the lubricating oil cooling unit (1) is circulated to form a warm-up circuit;

When the temperature of the lubricating oil measured by the temperature measuring unit (10) is greater than the first temperature threshold, the control unit (11) controls the internal cooling pipeline and the lubricating oil cooling unit (1) circulation conduction to form a lubricating oil cooling circuit, and controlling the circulation conduction of the internal cooling pipeline and the EGR cooling unit (2) to form an exhaust gas cooling circuit.
The engine cooling system according to claim 1, further comprising a temperature-sensing valve (3) and a cooling unit (4), when the temperature of the heat exchange fluid is greater than a second temperature threshold, the temperature-sensing valve (3) ) is opened, so that the heat dissipation unit (4) is circulated with the internal cooling pipeline, and the opening degree of the temperature-sensing valve (3) increases as the temperature of the heat exchange fluid increases.
The engine cooling system according to claim 1, wherein a first liquid infusion pump (5) is provided upstream of the internal cooling pipeline, and the liquid inlet of the first liquid infusion pump (5) is set to be connected with the lubrication The cooling cavity of the oil cooling unit (1) communicates with the cooling cavity of the EGR cooling unit (2).
The engine cooling system according to claim 3, further comprising a heating unit (6), the control unit (11) is set to be electrically connected to a heating switch, and when the heating switch is turned on, the control unit (11) controls The inner cooling pipeline, the EGR cooling unit (2) and the heating unit (6) are circulated and connected to form a heating circuit.
The engine cooling system according to claim 4, wherein a second infusion pump (7) is arranged upstream of the heating unit (6), and the liquid inlet of the second infusion pump (7) is set to be connected to the The cooling cavity of the EGR cooling unit (2) communicates.
The engine cooling system according to claim 5, wherein the first infusion pump (5) is a mechanical water pump or an electronic water pump, and the second infusion pump (7) is an electronic water pump.
The engine cooling system according to claim 4, wherein a three-way valve (8) is arranged downstream of the internal cooling pipeline, and the first outlet of the three-way valve (8) is arranged to be connected to the lubricating oil cooling unit (1) communicates with the cooling cavity, and the second outlet of the three-way valve (8) is set to communicate with the cooling cavity of the EGR cooling unit (2).
The engine cooling system according to claim 7, wherein a four-way valve (9) is arranged downstream of the EGR cooling unit (2), and the first outlet of the four-way valve (9) is set to communicate with the lubrication The cooling cavity of the oil cooling unit (1) is connected, the second outlet of the four-way valve (9) is set to communicate with the internal cooling pipeline, and the third outlet of the four-way valve (9) is set to be connected to the internal cooling pipeline. The heating cavity of the heating unit (6) is connected.
The engine cooling system according to claim 8, wherein the three-way valve (8) is a three-way solenoid valve, the four-way valve (9) is a four-way solenoid valve, and the control unit (11) and the The three-way solenoid valve is electrically connected to the four-way solenoid valve;

When the temperature of the lubricating oil is lower than the first temperature threshold, the control unit (11) controls the second outlet of the three-way solenoid valve to open, and controls the first outlet of the three-way solenoid valve to close , controlling the first outlet of the four-way solenoid valve to open, and controlling the second outlet and the third outlet of the four-way solenoid valve to close, so as to conduct the warm-up circuit;

When the temperature of the lubricating oil is greater than the first temperature threshold, the control unit (11) controls the opening of the first outlet and the second outlet of the three-way solenoid valve, and controls the opening of the four-way solenoid valve. The second outlet is opened, and the first outlet and the third outlet of the four-way electromagnetic valve are controlled to be closed, so as to conduct the lubricating oil cooling circuit and the exhaust gas cooling circuit;

When the heating switch is turned on, the control unit (11) controls the opening of the third outlet of the four-way solenoid valve, and controls the closing of the first outlet and the second outlet of the four-way solenoid valve, so as to lead Turn on the heating circuit and close the exhaust gas cooling circuit.
An automobile, comprising the engine cooling system according to any one of claims 1-9.