Thermal management system of engine, calibration method of thermal management system and thermal management method of thermal management system

Abstract

The embodiment of the invention discloses a thermal management system of an engine and a calibration method and a thermal management method of the thermal management system. An electronic thermostat is arranged, a first valve is arranged at a large circulation inlet of the electronic thermostat, a second valve is arranged at a small circulation outlet of the electronic thermostat, and a third valve is arranged at a large circulation outlet; the control module controls the circulation state of the heat management system at least according to the engine water temperature and controls the first valve, the second valve and the third valve to be closed in the microcirculation state. In the small circulation state, the first valve and the third valve are controlled to be closed, and the second valve is controlled to be opened; in the large circulation state, the first valve and the third valve are controlled to be opened, and the second valve is controlled to be closed. And through the use of the electronic thermostat, the opening or closing speed of the valve is increased, heat energy waste is reduced, and the heating efficiency is improved. Moreover, the heat management system can be controlled to work in a microcirculation state or a small circulation state, so that the circulation path is shortened, and the heating efficiency is further improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of cooling of internal combustion engine for vehicle, and in particular to a thermal management system of engine and a calibration method and a thermal management method thereof. BACKGROUND

[0002] Thermal management of engine is a key technology that affects its power, economy, emission and reliability.

[0003] At present, the widely used engine thermal management system mainly includes a mechanical water pump driven by the engine crankshaft, a paraffin thermostat, a radiator and a heater circuit. The coolant flows through the water jacket of the engine cylinder body and cylinder cover under the drive of the mechanical water pump to absorb heat. The paraffin thermostat controls its flow direction according to the coolant temperature: at low temperature, the large circulation passage is closed, and small circulation is carried out to accelerate the warm-up; at high temperature, the large circulation passage is opened, and the coolant flows through the radiator for heat dissipation.

[0004] However, in the existing thermal management system, the switching of the coolant between the large and small circulation depends on the physical opening of the paraffin thermostat after the water temperature rises, the whole process is passive and slow, and a large amount of combustion heat is taken away by the coolant and dissipated into the air, causing waste of heat energy and extremely low warm-up efficiency. SUMMARY

[0005] The present application provides a thermal management system and method of engine to improve the switching speed of large and small circulation through an electronic thermostat, reduce heat energy waste and improve warm-up efficiency.

[0006] According to an aspect of the present application, a thermal management system of engine is provided, comprising: a control module, an electronic water pump and an electronic thermostat;

[0007] The electronic thermostat comprises a plurality of inlets, a plurality of outlets, a first valve, a second valve and a third valve, wherein the plurality of inlets comprises a large circulation inlet and a micro-small circulation inlet, and the first valve is arranged at the large circulation inlet;

[0008] The plurality of outlets comprises a micro circulation outlet, a small circulation outlet and a large circulation outlet, a heater is arranged between the micro circulation outlet and the water pump inlet of the electronic water pump, the second valve is arranged at the small circulation outlet, the small circulation outlet is connected with the water pump inlet through a small circulation bypass branch, and the third valve is arranged at the large circulation outlet, and a radiator is arranged between the third valve and the water pump inlet;

[0009] The control module is connected with the electronic thermostat, and is configured to control a circulation state of the thermal management system according to at least the engine water temperature, and control the first valve, the second valve and the third valve to be closed in the micro circulation state; control the first valve and the third valve to be closed and the second valve to be opened in the small circulation state; and control the first valve and the third valve to be opened and the second valve to be closed in the large circulation state; wherein the water pump outlet of the electronic water pump is communicated with at least one micro circulation inlet in the micro circulation state, the small circulation state and the large circulation state.

[0010] Optionally, the control module is further connected with the electronic water pump, and the control module is further configured to control the electronic water pump to operate at a first rotating speed in the micro circulation state; control the electronic water pump to operate at a second rotating speed in the small circulation state; and control the electronic water pump to operate at a third rotating speed in the large circulation state, the second rotating speed being greater than the first rotating speed and less than the third rotating speed.

[0011] Optionally, the thermal management system further comprises a retarder, a fourth valve and a fifth valve.

[0012] The retarder is arranged between the water pump outlet and the large circulation inlet, the fourth valve is connected with the outlet of the retarder through a bypass branch of the retarder, and is configured to control a communication state between the water pump outlet and the outlet of the retarder; the fifth valve is configured to control a communication state between the water pump outlet and the inlet of the retarder; and the outlet of the retarder is connected with the first valve.

[0013] The control module is connected with the fourth valve and the fifth valve; and the large circulation state comprises at least one of a thermal engine mode, a retarder working mode and a failure protection mode.

[0014] The control module is further configured to control the fourth valve to be opened and the fifth valve to be closed in the micro circulation state, the small circulation state, the thermal engine mode and the failure protection mode; and control the fourth valve to be closed and the fifth valve to be opened in the retarder working mode.

[0015] According to another aspect of the present application, a thermal management method of an engine is provided, which is applied to the thermal management system of any embodiment of the present application; the thermal management method comprises:

[0016] controlling a circulation state of the thermal management system according to at least the engine water temperature, and controlling the first valve, the second valve and the third valve to be closed in the micro circulation state; controlling the first valve and the third valve to be closed and the second valve to be opened in the small circulation state; and controlling the first valve and the third valve to be opened and the second valve to be closed in the large circulation state; wherein the water pump outlet of the electronic water pump is communicated with the micro circulation inlet in the micro circulation state, the small circulation state and the large circulation state.

[0017] Optionally, the method further comprises: in the micro-cycle state, controlling the electronic water pump to operate at a first rotating speed; in the small-cycle state, controlling the electronic water pump to operate at a second rotating speed; in the large-cycle state, controlling the electronic water pump to operate at a third rotating speed, the second rotating speed being greater than the first rotating speed and less than the third rotating speed.

[0018] Optionally, the thermal management system further comprises a retarder, a fourth valve and a fifth valve; the large-cycle state comprises at least one of a thermal mode, a retarder working mode and a failure protection mode; the thermal management method further comprises:

[0019] in the micro-cycle state, the small-cycle state, the thermal mode and the failure protection mode, controlling the fourth valve to be open and the fifth valve to be closed; and in the retarder working mode, controlling the fourth valve to be closed and the fifth valve to be open.

[0020] Optionally, the cycle state of the thermal management system is controlled according to at least the engine water temperature, comprising:

[0021] in a case where it is determined that the retarder does not need to work, in a case where the engine water temperature is in a first temperature range, controlling the thermal management system to work in the micro-cycle state or the small-cycle state according to the engine operating condition; in a case where the engine water temperature is in a second temperature range, controlling the thermal management system to work in the small-cycle state; in a case where the engine water temperature is in a third temperature range, controlling the thermal management system to work in the thermal mode; in a case where a duration of the engine water temperature being in a fourth temperature range exceeds a preset duration threshold, controlling the thermal management system to work in the failure protection mode; wherein the temperatures of the first temperature range, the second temperature range, the third temperature range and the fourth temperature range increase in turn; an opening degree of the first valve in the thermal mode is less than or equal to an opening degree of the first valve in the failure protection mode, and / or, an opening degree of the third valve in the thermal mode is less than or equal to an opening degree of the third valve in the failure protection mode;

[0022] in a case where it is determined that the retarder needs to work, controlling the thermal management system to work in the retarder working mode.

[0023] Optionally, the cycle state of the thermal management system is controlled according to at least the engine water temperature, comprising:

[0024] controlling the opening degree of the valve of the electronic thermostat and the rotating speed of the electronic water pump according to the engine water temperature, the engine operating condition and a preset corresponding relationship; the engine operating condition comprises a rotating speed and a torque of the engine; the preset corresponding relationship comprises a corresponding relationship between the engine water temperature, the engine operating condition and the opening degree of the valve of the electronic thermostat and the rotating speed of the electronic water pump; the opening degree of the valve of the electronic thermostat comprises opening degrees of the third valve, the fourth valve and the fifth valve;

[0025] wherein, the preset corresponding relationship is obtained based on a bench test of the engine.

[0026] According to another aspect of the present application, there is provided a calibration method of a thermal management system of an engine, optionally for calibrating the thermal management system of any embodiment of the present application, the calibration method comprising:

[0027] Based on a bench test of the engine, at least according to a plurality of parameters including the outlet water temperature, the cylinder block jacket water temperature, the oil temperature, the cylinder head wall surface temperature and the fuel consumption of the engine, a corresponding relationship between the outlet water temperature and the engine operating condition and the valve opening degree of the electronic thermostat and the rotating speed of the electronic water pump is determined as a preset corresponding relationship for calibration.

[0028] Optionally, based on a bench test of the engine, at least according to a plurality of parameters including the outlet water temperature, the cylinder block jacket water temperature, the oil temperature, the cylinder head wall surface temperature and the fuel consumption of the engine, a corresponding relationship between the outlet water temperature and the engine operating condition and the valve opening degree of the electronic thermostat and the rotating speed of the electronic water pump is determined as a preset corresponding relationship for calibration, comprising:

[0029] In the thermal management system, in the microcirculation state, the first valve, the second valve and the third valve are all closed, and in the case that the temperature difference between the inlet and outlet water of the exhaust gas recirculation (EGR) cooler exceeds a first temperature threshold, a second target opening degree of the second valve is calibrated;

[0030] The calibration of the second target opening degree of the second valve comprises:

[0031] The engine is controlled to start from a cold state, idle for a set time to a first test operating condition; in the first test operating condition, the first valve and the third valve are controlled to be closed;

[0032] In the first test operating condition from low load to high load, the rotating speed of the electronic water pump and / or the opening degree of the second valve are adjusted in each first test operating condition in a first rotating speed range until the first test stop condition or the second test stop condition is met, the test is stopped, and the opening degree of the second valve corresponding to the second test stop condition is taken as the second target opening degree of the second valve in the first test operating condition, and the rotating speed of the electronic water pump corresponding to the second test stop condition is taken as the first target rotating speed in the first test operating condition;

[0033] In the case that the first test stop condition is met, the opening degree of the second valve is increased, and / or the rotating speed of the electronic water pump is increased, and the engine is controlled to start from a cold state, idle for a set time to a first test operating condition until the second test stop condition is met;

[0034] The first test stop condition comprises that the outlet water temperature reaches a first preset temperature later than at least one other condition, and the second test stop condition comprises that the outlet water temperature reaches the first preset temperature earlier than the other conditions.

[0035] The other conditions include that the cylinder jacket water temperature reaches a second preset temperature, the oil temperature reaches a third preset temperature, and the cylinder head wall surface temperature reaches a fourth preset temperature.

[0036] Optionally, based on the bench test of the engine, the correspondence between the outlet water temperature and the engine operating condition and the opening degree of the valve of the electronic thermostat and the rotating speed of the electronic water pump is determined according to at least multiple parameters of the outlet water temperature, the cylinder jacket water temperature, the oil temperature, the cylinder head wall surface temperature, and the fuel consumption of the engine, as a preset correspondence for calibration, including:

[0037] The engine is controlled to start from a cold state, run at an idle speed for a set time to a second test operating condition; under the second test operating condition, the first valve and the third valve are controlled to be closed;

[0038] From the low load to the high load, the second test operating condition, in each second test operating condition, the rotating speed of the electronic water pump in the second rotating speed range and / or the second valve are adjusted in the second rotating speed range until the third test stop condition or the fourth test stop condition is met, the test is stopped, and the opening degree of the fourth test stop condition corresponding to the second valve is taken as the second target opening degree of the second valve under the second test operating condition, and the corresponding electronic water pump is taken as the second target rotating speed under the second test operating condition;

[0039] In the case where the third test stop condition is reached, the second valve opening degree is increased, and / or the rotating speed of the electronic water pump is increased, and the engine is returned to be controlled to start from a cold state, run at an idle speed for a set time to a second test operating condition, until the fourth test stop condition is met;

[0040] The third test stop condition includes that the outlet water temperature reaches a fifth preset temperature later than at least one of the other conditions; the fourth test stop condition includes that the outlet water temperature reaches the fifth preset temperature earlier than the other conditions.

[0041] The other conditions include that the cylinder jacket water temperature reaches a sixth preset temperature, the oil temperature reaches a seventh preset temperature, and the cylinder head wall surface temperature reaches an eighth preset temperature.

[0042] Optionally, based on the bench test of the engine, the correspondence between the outlet water temperature and the engine operating condition and the opening degree of the valve of the electronic thermostat and the rotating speed of the electronic water pump is determined according to at least multiple parameters of the outlet water temperature, the cylinder jacket water temperature, the oil temperature, the cylinder head wall surface temperature, and the fuel consumption of the engine, as a preset correspondence for calibration, including:

[0043] In the case where the first valve and the third valve are fully open and the second valve is closed, the target outlet water temperature corresponding to each third test operating condition is calibrated; the target outlet water temperature meets the lowest fuel consumption under the third test operating condition.

[0044] According to the third test working condition and the corresponding target outlet water temperature, the opening degrees of the first valve and the third valve are adjusted at the first set rotating speed of the electronic water pump until the outlet water temperature reaches the corresponding target outlet water temperature, and the opening degree of the first valve and the opening degree of the third valve when the target outlet water temperature is reached are taken as the first target opening degree of the first valve and the third target opening degree of the third valve respectively under the third test working condition.

[0045] Optionally, the thermal management system further comprises a retarder, a fourth valve and a fifth valve; the large circulation state comprises a retarder working mode; based on a bench test of the engine, the correspondence relationship between the outlet water temperature and the engine working condition, the valve opening degree of the electronic thermostat and the rotating speed of the electronic water pump is determined according to at least multiple parameters of the outlet water temperature, the cylinder block water jacket water temperature, the oil temperature, the cylinder head wall surface temperature and the fuel consumption, as a calibrated preset correspondence relationship, comprising:

[0046] In the case that the first valve and the third valve are fully opened, the second valve is closed, the fourth valve is closed and the fifth valve is fully opened, the target outlet water temperature corresponding to each fourth test working condition is calibrated; the target outlet water temperature satisfies the lowest fuel consumption under the fourth test working condition;

[0047] According to the fourth test working condition and the corresponding target outlet water temperature, the opening degrees of the first valve and the third valve are adjusted at the second set rotating speed of the electronic water pump until the outlet water temperature reaches the corresponding target outlet water temperature, and the opening degree of the first valve and the opening degree of the third valve when the target outlet water temperature is reached are taken as the first target opening degree of the first valve and the third target opening degree of the third valve respectively under the fourth test working condition.

[0048] The thermal management system of the engine and the calibration method and the thermal management method of the engine of the embodiment of the application, by setting the electronic thermostat, setting the first valve at the large circulation inlet of the electronic thermostat, setting the second valve at the micro circulation outlet of the electronic thermostat and setting the third valve at the large circulation outlet, connecting the control module with the electronic thermostat, controlling the circulation state of the thermal management system according to at least the engine water temperature, and in the micro circulation state, controlling the first valve, the second valve and the third valve to be closed, in the small circulation state, controlling the first valve and the third valve to be closed and controlling the second valve to be opened, and in the large circulation state, controlling the first valve and the third valve to be opened and controlling the second valve to be closed. In this way, by using the electronic thermostat, the speed of opening or closing the valve is improved, the response speed of the thermal management system is improved, which is beneficial to reducing the waste of thermal energy and improving the warm-up efficiency. Moreover, it can be realized that in the working condition of low engine water temperature, by controlling the thermal management system to work in the micro circulation state or the small circulation state, the circulation path is shortened, the fast warm-up is realized, and the warm-up efficiency is further improved. In the working condition of high engine water temperature, by controlling the thermal management system to work in the large circulation state, the control of the engine water temperature in the large circulation state is realized, which is beneficial to reducing the fuel consumption.

[0049] It should be understood that the matters described in this section are not intended to identify key or essential features of the embodiments of the application, nor are they intended to limit the scope of the application. Other features of the present application will be apparent from the following description. BRIEF DESCRIPTION OF DRAWINGS

[0050] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the embodiments will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative effort based on these drawings.

[0051] Figure 1 is a structural schematic diagram of a thermal management system provided by an embodiment of the present application;

[0052] Figure 2 is a structural schematic diagram of another thermal management system of an engine provided by an embodiment of the present application;

[0053] Figure 3 is a flowchart of a thermal management method of an engine provided by an embodiment of the present application;

[0054] Figure 4 is a flowchart of another thermal management method of an engine provided by an embodiment of the present application;

[0055] Figure 5 is a flowchart of a calibration method of a thermal management system of an engine provided by an embodiment of the present application;

[0056] Figure 6 is a flowchart of another calibration method of a thermal management system of an engine provided by an embodiment of the present application;

[0057] Figure 7 is a specific flowchart of calibration when a small circulation state is adopted for circulation when the temperature difference of water in and out of an EGR cooler is too large;

[0058] Figure 8 is a flowchart of another calibration method of a thermal management system of an engine provided by an embodiment of the present application;

[0059] Figure 9 is a specific flowchart of calibration when a small circulation state is adopted for circulation;

[0060] Figure 10 is a flowchart of another calibration method of a thermal management system of an engine provided by an embodiment of the present application;

[0061] Figure 11 is a flowchart of another calibration method of a thermal management system of an engine provided by an embodiment of the present application. DETAILED DESCRIPTION

[0062] In order to better understand the technical scheme of the present application, the technical scheme in the embodiments of the present application will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work should belong to the scope of protection of the present application.

[0063] It should be noted that the terms "first", "second", and the like in the specification and claims of the present application and the above-described drawings are used to distinguish similar objects, and do not necessarily have to be used to describe a specific order or sequence. It should be understood that the data thus used can be interchanged under appropriate circumstances, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion, for example, a process, method, system, product or device including a series of steps or units does not have to be limited to those steps or units clearly listed, but can include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0064] The embodiment of the present application provides a heat management system of an engine, Figure 1 is a structural schematic diagram of a heat management system provided by the embodiment of the present application, referring to Figure 1The heat management system comprises a control module (not shown in the figure), an electronic water pump 1 and an electronic thermostat 2. The electronic thermostat 2 comprises a plurality of inlets, a plurality of outlets, a first valve F1, a second valve F2 and a third valve F3. The plurality of inlets comprises a macro circulation inlet and a micro circulation inlet, and the first valve F1 is arranged at the macro circulation inlet. The plurality of outlets comprises a micro circulation outlet, a small circulation outlet and a macro circulation outlet, and the micro circulation outlet is arranged between the electronic water pump 1 and the water pump inlet. The second valve F2 is arranged at the small circulation outlet, and the small circulation outlet is connected with the water pump inlet through a small circulation bypass branch 4. The third valve F3 is arranged at the macro circulation outlet, and the third valve F3 is arranged between the water pump inlet and the radiator 5. The control module is connected with the electronic thermostat 2, and is used for controlling the circulation state of the heat management system according to at least the engine water temperature, and controlling the first valve F1, the second valve F2 and the third valve F3 to be closed in the micro circulation state. In the small circulation state, the first valve F1 and the third valve F3 are controlled to be closed, and the second valve F2 is controlled to be opened. In the macro circulation state, the first valve F1 and the third valve F3 are controlled to be opened, and the second valve F2 is controlled to be closed. In the micro circulation state, the small circulation state and the macro circulation state, the water pump outlet of the electronic water pump 1 is communicated with at least one micro circulation inlet.

[0065] The control module can be an electronic control unit (ECU) of the vehicle.

[0066] In the heat management system, the electronic water pump 1 and the electronic thermostat 2 are connected with the control module, and the control module can control the rotating speed of the electronic water pump 1 and the opening and closing state of the valves in the electronic thermostat 2, which includes the opening state, the closing state and the opening degree in the conducting state.

[0067] The electronic thermostat 2 comprises a micro circulation inlet, a macro circulation inlet, a micro circulation outlet, a small circulation outlet and a macro circulation outlet, and in the micro circulation state, the small circulation state and the macro circulation state, the water pump outlet of the electronic water pump 1 is communicated with at least one micro circulation inlet. The electronic thermostat further comprises a first valve F1, a second valve F2 and a third valve F3. The first valve F1 is arranged at the macro circulation inlet and can control the communication state between the water pump outlet and the macro circulation inlet. The second valve F2 is arranged at the small circulation outlet and can control the communication state between the small circulation outlet and the water pump inlet. The third valve F3 is arranged at the macro circulation outlet and can control the communication state between the macro circulation outlet and the water pump inlet. The first valve F1, the second valve F2 and the third valve F3 can be ball valves or other forms of valves, which are not limited in the embodiments of the present application. Figure 1 The specific structure of the heat management system is exemplarily shown, and the specific structure of the heat management system is described with reference to Figure 1The thermal management system can further include a block water jacket 6, a head water jacket 7, an air compressor 8, a supercharger 9, a mixer 10, a cooler 11, a vaporizer 12, and an expansion tank 13. Optionally, the cooler 11 includes an EGR cooler and an oil cooler. The inlet of the block water jacket 6 is connected to the outlet of the water pump, the outlet of the block water jacket 6 is connected to the inlet of the head water jacket 7, the inlet of the air compressor 8, and the inlet of the supercharger 9, respectively, the outlet of the head water jacket 7 and the outlet of the air compressor 8 can be merged at the collector 14 and be branched at the collector 14, one branch passes through the vaporizer 12 to return to the outlet of the water pump, one branch passes through the mixer 10 to connect to the first micro-circulation inlet a1, one branch passes through the EGR cooler to connect to the second micro-circulation inlet a2, and the outlet of the supercharger 9 connects to the third micro-circulation inlet a3.

[0068] The control module can control the circulation state of the thermal management system according to the engine water temperature. When the engine water temperature is low, the first valve F1, the second valve F2, and the third valve F3 can be controlled to be closed, and the water outlet of the water pump outlet reaches the micro-circulation inlet and then returns to the water pump inlet through the heater core 3, so that the thermal management system is in a micro-circulation state, the circulation path is the shortest, and rapid warming is achieved. For example, for the thermal management system shown in Figure 1 The electronic water pump 11 works at a small duty cycle speed (for example, 20% to 40% duty cycle speed), and the cooling liquid passes through the block water jacket 6 and is divided into three paths of the head water jacket 7, the air compressor 8, and the supercharger 9, one of which enters the electronic thermostat 2 after passing through the supercharger 9; the other two paths of cooling water pass through the head water jacket 7 and the air compressor 8, and then enter the collector 14 and are divided into three paths, one of which returns to the electronic water pump 1 through the natural gas vaporizer 12, the second path passes through the mixer 10, and the third path enters the cooler 11, and the second path and the third path merge to enter the electronic thermostat 2 and then return to the electronic water pump 1 through the heater core 3.

[0069] After the engine water temperature rises to a certain extent, the second valve F2 can be controlled to be opened, and the first valve F1 and the third valve F3 remain closed, and the system enters a small circulation state. The water outlet of the water pump outlet reaches the micro-circulation inlet, one branch returns to the water pump inlet through the heater core 3, and the other branch returns to the water pump inlet through the small circulation bypass, which is also conducive to rapid warming. For example, for the thermal management system shown in Figure 1The electronic water pump 11 works at a moderate duty cycle speed (for example, 40% speed) in the heat management system shown. The cooling liquid flows through the cylinder block water jacket 6, and is then divided into three paths, the cylinder head water jacket 7, the air compressor 8, and the supercharger 9. One path of the cooling water passes through the supercharger 9 and then enters the electronic thermostat 2. The other two paths of the cooling water pass through the cylinder head water jacket 7 and the air compressor 8, and then enter the collector 14, which is then divided into three paths. One path passes through the natural gas vaporizer 12 and returns to the electronic water pump 1. The second path passes through the mixer 10. The third path enters the cooler 11. The second path and the third path are combined and then divided into two paths after entering the electronic thermostat 2. One path passes through the heater 3 and returns to the electronic water pump 1. The other path passes through the small circulation bypass branch 4 and returns to the electronic water pump 1.

[0070] After the engine is warmed up, the engine water temperature reaches a high temperature. In this case, the first valve F1 and the third valve F3 are controlled to be open, and the second valve F2 is controlled to be closed, entering the large circulation state. The water outlet of the pump outlet enters the electronic thermostat 2 through the small circulation inlet and the large circulation inlet. Then, one path passes through the heater 3 and returns to the pump inlet. The other path passes through the radiator 5 and returns to the pump inlet. The position of the radiator 5 can be provided with an electric control fan to accelerate the cooling speed, thereby realizing the control of the engine water temperature in the large circulation state. For example, for a 2.0L engine, the water temperature is controlled to be 95°C in the large circulation state. Figure 1 The electronic water pump 11 works at 100% speed in the heat management system shown. The cooling liquid flows through the cylinder block water jacket 6, and is then divided into three paths, the cylinder head water jacket 7, the air compressor 8, and the supercharger 9. One path of the cooling water passes through the supercharger 9 and then enters the electronic thermostat 2. The other two paths of the cooling water pass through the cylinder head water jacket 7 and the air compressor 8, and then enter the collector 14, which is then divided into three paths. One path passes through the natural gas vaporizer 12 and returns to the electronic water pump 1. The second path passes through the mixer 10. The third path enters the cooler 11. The second path and the third path are combined and then divided into two paths after entering the electronic thermostat 2. One path passes through the heater 3 and returns to the electronic water pump 1. The other path passes through the radiator 5 and returns to the electronic water pump 1.

[0071] The thermal management system of the engine of the embodiment is provided with an electronic thermostat, a first valve at the large circulation inlet of the electronic thermostat, a second valve at the small circulation outlet of the electronic thermostat, and a third valve at the large circulation outlet. A control module is connected with the electronic thermostat, and controls the circulation state of the thermal management system according to at least the engine water temperature, and controls the first valve, the second valve and the third valve to be closed in the micro circulation state. In the small circulation state, the first valve and the third valve are controlled to be closed, and the second valve is controlled to be opened. In the large circulation state, the first valve and the third valve are controlled to be opened, and the second valve is controlled to be closed. In this way, the use of the electronic thermostat improves the speed of opening or closing of the valves, improves the response speed of the thermal management system, and is beneficial to reducing the waste of thermal energy and improving the warming efficiency. Moreover, the micro circulation state or the small circulation state of the thermal management system can be controlled in the working condition of low engine water temperature, the circulation path is shortened, rapid warming is realized, and the warming efficiency is further improved. In the working condition of high engine water temperature, the large circulation state of the thermal management system is controlled, the engine water temperature in the large circulation state is controlled, and fuel consumption is reduced.

[0072] With reference to the foregoing Figure 1 Optionally, the control module is also connected with the electronic water pump 1, and the control module is also used for controlling the electronic water pump 1 to operate at a first rotating speed in the micro circulation state, controlling the electronic water pump 1 to operate at a second rotating speed in the small circulation state, and controlling the electronic water pump 1 to operate at a third rotating speed in the large circulation state, the second rotating speed being greater than the first rotating speed and less than the third rotating speed.

[0073] Specifically, in the micro circulation state, the electronic water pump 1 operates at a lower first rotating speed, so that the water output of the electronic water pump 1 is small, and the engine water temperature is rapidly increased in the micro circulation state, so that rapid warming is realized. In the large circulation state, the electronic water pump 1 is controlled to operate at a higher third rotating speed, so that the water output of the electronic water pump 1 is large, and the control of the engine water temperature in the large circulation state is realized. In the small circulation state, the electronic water pump 1 is controlled to operate at a second rotating speed between the first rotating speed and the third rotating speed. The above rotating speed control mode of the electronic water pump 1 is beneficial to reducing the shaft power of the water pump and improving fuel consumption.

[0074] In the related art, some thermal management systems also include a retarder. A traditional heavy-duty natural gas engine cooling system with a retarder has the characteristics of large cooling water volume, large heat dissipation demand, large system pressure loss, etc., and often needs to be equipped with more powerful water pump, fan and other components to increase water flow and air intake, thereby improving the thermal balance capability of the vehicle thermal management system. In addition, the retarder only works in scenarios such as long downhill, frequent braking and wet road surface, and in most other working conditions, the retarder does not work. In the related art, in the working condition where the retarder does not work, the cooling water also needs to be heat exchanged through the retarder, which causes great energy waste. Based on the above problems, the embodiment of the present application provides another thermal management system of an engine, Figure 2 is a structural schematic diagram of another thermal management system of an engine provided by the embodiment of the present application, referring to Figure 2 Optionally, the thermal management system of the engine further includes a retarder 15, a fourth valve F4 and a fifth valve F5. The retarder 15 is arranged between the water pump outlet and the large circulation inlet. The fourth valve F4 is connected to the outlet of the retarder 15 through a retarder bypass branch 16 and is used to control the communication state between the water pump outlet and the outlet of the retarder 15. The fifth valve F5 is used to control the communication state between the water pump outlet and the inlet of the retarder 15. The outlet of the retarder 15 is connected to the first valve F1. The control module is connected to the fourth valve F4 and the fifth valve F5. The large circulation state includes at least one of the thermal engine mode, the retarder 15 working mode and the failure protection mode. The control module is further used to control the fourth valve F4 to be opened and the fifth valve F5 to be closed in the micro circulation state, the small circulation state, the thermal engine mode and the failure protection mode, and is used to control the fourth valve F4 to be closed and the fifth valve F5 to be opened in the retarder 15 working mode.

[0075] By arranging the fourth valve F4 and the fifth valve F5 at the inlet of the retarder 15, in the working modes other than the retarder 15 working mode, for example, the micro circulation state, the small circulation state, the thermal engine mode and the failure protection mode, the control module controls the fourth valve F4 to be opened and the fifth valve F5 to be closed, so that in the mode where the retarder 15 does not need to work, the cooling liquid in the thermal management system flows through the retarder bypass branch 16 without passing through the retarder 15, and the cooling liquid does not need to be heat exchanged through the retarder 15, thereby reducing energy waste and reducing fuel consumption. In the retarder 15 working mode, the control module controls the fourth valve F4 to be closed and the fifth valve F5 to be opened, so that in the retarder 15 working mode, the cooling liquid in the thermal management system flows through the retarder 15 and does not pass through the retarder bypass branch 16, thereby meeting the working condition requirements in scenarios such as long downhill, frequent braking and wet road surface. For Figure 2In the microcirculation state, the small circulation state, the thermal engine mode and the failure protection mode of the heat management system, the water outlet of the electronic water pump 1 is connected with the micro-small circulation inlet, and the cooling liquid flows through the engine block water jacket 6 and is then divided into three paths, i.e., the cylinder head water jacket 7, the air compressor 8 and the supercharger 9.

[0076] The embodiment of the present application further provides a heat management method of an engine, and the heat management method of the engine can be applied to the heat management system of any embodiment of the present application. Figure 3 The heat management method of the engine is shown in the flowchart of FIG. 6. Figure 3 The heat management method comprises the following steps.

[0077] S210, controlling the circulation state of the heat management system according to the engine water temperature, and in the microcirculation state, controlling the first valve, the second valve and the third valve to be closed; in the small circulation state, controlling the first valve and the third valve to be closed and the second valve to be opened; and in the large circulation state, controlling the first valve and the third valve to be opened and the second valve to be closed.

[0078] In the microcirculation state, the small circulation state and the large circulation state, the water pump outlet of the electronic water pump is connected with the micro-small circulation inlet.

[0079] Optionally, the heat management method further comprises the following steps.

[0080] S220, in the microcirculation state, controlling the electronic water pump to operate at a first rotating speed; in the small circulation state, controlling the electronic water pump to operate at a second rotating speed; and in the large circulation state, controlling the electronic water pump to operate at a third rotating speed, wherein the second rotating speed is greater than the first rotating speed and less than the third rotating speed.

[0081] The heat management method of the embodiment of the present application is applied to the heat management system of any embodiment of the present application, has the beneficial effects of the heat management system of any embodiment of the present application, and will not be described here again.

[0082] In combination Figure 2 The heat management system further comprises a retarder, a fourth valve and a fifth valve; the large circulation state comprises at least one of a heat engine mode, a retarder working mode and a failure protection mode. Figure 4 is a flow chart of another engine heat management method provided by the embodiment of the present application, referring to Figure 4 The heat management method comprises:

[0083] S310, controlling the circulation state of the heat management system according to at least the engine water temperature, and in the micro circulation state, controlling the first valve, the second valve and the third valve to be closed; in the small circulation state, controlling the first valve and the third valve to be closed and the second valve to be opened; in the large circulation state, controlling the first valve and the third valve to be opened and the second valve to be closed.

[0084] In the micro circulation state, the small circulation state and the large circulation state, the water pump outlet of the electronic water pump is in communication with the micro-small circulation inlet.

[0085] S320, in the micro circulation state, controlling the electronic water pump to operate at a first rotating speed; in the small circulation state, controlling the electronic water pump to operate at a second rotating speed; in the large circulation state, controlling the electronic water pump to operate at a third rotating speed, the second rotating speed being greater than the first rotating speed and less than the third rotating speed.

[0086] S330, in the micro circulation state, the small circulation state, the heat engine mode and the failure protection mode, controlling the fourth valve to be opened and the fifth valve to be closed; and in the retarder working mode, controlling the fourth valve to be closed and the fifth valve to be opened.

[0087] In some embodiments, in S210 and S310, controlling the circulation state of the heat management system according to at least the engine water temperature comprises:

[0088] In the case of determining that the retarder does not need to work, in the case of the engine water temperature being in the first temperature range, controlling the heat management system to work in the micro circulation state or the small circulation state according to the engine working condition; in the case of the engine water temperature being in the second temperature range, controlling the heat management system to work in the small circulation state; in the case of the engine water temperature being in the third temperature range, controlling the heat management system to work in the heat engine mode; in the case of the duration of the engine water temperature being in the fourth temperature range exceeding a preset duration threshold, controlling the heat management system to work in the failure protection mode; wherein the temperatures of the first temperature range, the second temperature range, the third temperature range and the fourth temperature range increase in turn; in the case of determining that the retarder needs to work, controlling the heat management system to work in the retarder working mode.

[0089] Optionally, the control module can determine whether the retarder needs to work based on the vehicle working condition. The retarder usually needs to work in the scene of long downhill, frequent braking and wet road, that is, the brake time is longer or the brake frequency is higher. Optionally, the control module determines that the retarder needs to work when the brake distance of the vehicle exceeds the preset distance, or the brake frequency exceeds the preset frequency, otherwise it is determined that the retarder does not need to work. In the case of determining that the retarder needs to work, no matter which temperature interval the engine water temperature is in, the thermal management system is controlled to work in the retarder working mode to adapt to the scene demand of long downhill, frequent braking and wet road of the vehicle.

[0090] Optionally, a temperature sensor is arranged at the electronic thermostat. In some embodiments, the temperature detected by the temperature sensor at the electronic thermostat can be used as the engine water temperature. The temperature sensor is connected with the control module in the thermal management system. In the case of determining that the retarder does not need to work, the control module controls the circulation state of the thermal management system according to the temperature interval to which the engine water temperature belongs. When the engine water temperature is in a very low first temperature interval, the thermal management system can be controlled to work in a micro-circulation state or a small circulation state, so that the engine water temperature rises rapidly to achieve rapid warming. When the engine water temperature is in the first temperature interval, the thermal management system can be controlled to circulate in a micro-circulation state in some engine working conditions, and in a small circulation state in other engine working conditions, which can be calibrated according to the bench test of the engine. When the engine water temperature is in a second temperature interval, it means that the micro-circulation or small circulation has a certain effect, and the thermal management system is controlled to work in a small circulation state to keep the engine water temperature continue to rise at a faster speed. When the engine water temperature is in a third temperature interval, it means that the engine water temperature is already high, and in this case the thermal management system is controlled to work in a hot engine mode. When the engine water temperature is in a fourth temperature interval, it means that the engine water temperature is too high, and in the case that the duration of the engine water temperature in the fourth temperature interval exceeds a preset duration threshold, the engine water temperature needs to be lowered for failure protection, and in this case the opening degree of the first valve and the opening degree of the third valve can be adjusted to the maximum to make the engine water temperature lower than the minimum value of the temperature in the fourth temperature interval, realizing failure protection.

[0091] In the hot engine mode, the opening degree of the first valve is less than or equal to the opening degree of the first valve in the failure protection mode, and / or the opening degree of the third valve in the hot engine mode is less than or equal to the opening degree of the third valve in the failure protection mode, so as to ensure lower fuel consumption in the hot engine mode.

[0092] The temperatures of the first temperature interval, the second temperature interval, the third temperature interval and the fourth temperature interval increase in turn, that is, the highest temperature in the first temperature interval is less than the lowest temperature in the second temperature interval, the highest temperature in the second temperature interval is less than the lowest temperature in the third temperature interval, and the highest temperature in the third temperature interval is less than the lowest temperature in the fourth temperature interval. The first temperature interval, the second temperature interval, the third temperature interval and the fourth temperature interval can be set according to actual needs, or can be calibrated according to a bench test of the engine. For example, the first temperature interval is [-40℃, 40℃], the first temperature interval is [40℃, 85℃], the first temperature interval is [85℃, 105℃], and the fourth temperature interval is greater than 105℃. The fourth temperature interval can be calibrated according to a limit alarm water temperature of the engine. Optionally, the lowest temperature of the fourth temperature interval is less than the limit alarm water temperature. For example, the lowest temperature of the fourth temperature interval is equal to the limit alarm water temperature minus a preset temperature allowance. The preset temperature allowance can be a small temperature. For example, the preset temperature allowance is 5-8℃, so that the first valve and the third valve of the electronic thermostat are adjusted to the maximum opening degree in advance before the engine water temperature alarm, to ensure that the flow through the radiator is maximum and the system heat dissipation capacity is increased.

[0093] On the basis of the above embodiment, in S210 and S310, at least according to the engine water temperature, the circulating state of the thermal management system is controlled, including: according to the engine water temperature, the engine working condition and the preset corresponding relationship, the opening degree of the valve of the electronic thermostat and the rotating speed of the electronic water pump are controlled; the engine working condition includes the rotating speed and the torque of the engine; the preset corresponding relationship includes the corresponding relationship of the engine water temperature, the engine working condition and the opening degree of the valve of the electronic thermostat and the rotating speed of the electronic water pump; the opening degree of the valve of the electronic thermostat includes the opening degree of the third valve, the fourth valve and the fifth valve; wherein, the preset corresponding relationship is obtained based on the calibration of the engine bench test.

[0094] Specifically, during the engine bench test, the boundary parameters such as the outlet water temperature, the inlet water temperature, the temperature difference between the inlet and outlet water of the EGR cooler, the oil temperature and the metal temperature of the engine, and the result parameters such as fuel consumption can be tested, to obtain the target opening degree of the valve in the thermal management system and the target rotating speed of the electronic water pump under at least part of the circulating state, to provide basic reference data for the calibration of the whole vehicle application, and to support the industrialization application of the thermal management system. Through the engine bench test, the preset corresponding relationship is obtained, and after the preset corresponding relationship is stored, the opening degree of the valve of the electronic thermostat and the rotating speed of the electronic water pump can be determined based on the preset corresponding relationship and the engine working condition and the engine water temperature when the thermal management system is applied to the whole vehicle.

[0095] The preset corresponding relationship includes a multi-dimensional corresponding relationship of the engine water temperature, the engine working condition, and the valve opening degree of the electronic thermostat and the rotating speed of the electronic water pump.Optionally, during the bench test, the lowest fuel consumption is taken as the target for calibration in the thermal engine mode, so as to ensure that the thermal management system operates at the lowest fuel consumption in the thermal engine mode, and to realize the engine water temperature control under the best fuel consumption.

[0096] The embodiment of the present application further provides a calibration method of a thermal management system of an engine. Figure 5 is a flowchart of the calibration method of the thermal management system of the engine provided by the embodiment of the present application, referring to Figure 5 The calibration method comprises the following steps.

[0097] S410, based on the bench test of the engine, at least according to multiple parameters of the water outlet temperature, the cylinder block water jacket temperature, the oil temperature, the cylinder cover wall surface temperature and the fuel consumption of the engine, the corresponding relationship of the water outlet temperature and the engine working condition and the valve opening degree of the electronic thermostat and the rotating speed of the electronic water pump is determined as the preset corresponding relationship of calibration.

[0098] During the calibration of the micro-cycle state and the small-cycle state, the corresponding relationship of the water outlet temperature and the engine working condition and the valve opening degree of the electronic thermostat and the rotating speed of the electronic water pump can be determined according to the water outlet temperature, the cylinder block water jacket temperature, the oil temperature and the cylinder cover wall surface temperature of the engine.

[0099] During the calibration of the thermal engine mode and the retarder working mode, the corresponding relationship of the water outlet temperature and the engine working condition and the valve opening degree of the electronic thermostat and the rotating speed of the electronic water pump can be determined according to the water outlet temperature and the fuel consumption of the engine.

[0100] It should be noted that calibration is not required in the failure protection mode, in the failure protection mode, the second valve of the electronic thermostat is closed, and the first valve and the third valve are fully open. In the heat management system including the retarder, in the retarder working mode, the fourth valve is controlled to be closed, and the fifth valve is fully open; in the micro-circulation state, the small circulation state and the heat engine mode, the fourth valve is controlled to be fully open, and the fifth valve is closed.

[0101] After the calibration of the micro-circulation state, the small circulation state, the heat engine mode and the retarder working mode is completed, the correspondence between the water outlet temperature and the engine working condition and the opening degree of the valve of the electronic thermostat and the rotating speed of the electronic water pump in the micro-circulation state, the small circulation state, the heat engine mode and the retarder working mode is taken as a preset correspondence, and then the preset correspondence can be stored, and when the subsequent heat management method is executed, the heat management system can be controlled based on the preset correspondence. In the preset correspondence, the water outlet temperature of the engine can correspond to the engine water temperature, and in the heat management method, the circulation state of the heat management system is controlled according to the engine water temperature, specifically, the circulation state of the engine under the same water outlet temperature can be determined in the preset correspondence according to the engine water temperature, and the heat management system is controlled to work in the determined circulation state.

[0102] The calibration method of the heat management system of the embodiment of the application determines the correspondence between the water outlet temperature and the engine working condition and the opening degree of the valve of the electronic thermostat and the rotating speed of the electronic water pump according to at least multiple parameters of the water outlet temperature of the engine, the cylinder block water jacket water temperature, the oil temperature and the cylinder cover wall surface temperature and the fuel consumption, as the preset correspondence of calibration, and after the preset correspondence is stored, the opening degree of the valve of the electronic thermostat and the rotating speed of the electronic water pump can be determined based on the preset correspondence and the engine working condition and the engine water temperature when the heat management system is applied to the whole vehicle, so that the warm-up efficiency of the heat management system is ensured, and the fuel consumption is improved.

[0103] Optionally, S410 comprises: in the heat management system, in the micro-circulation state, the first valve, the second valve and the third valve are all closed, and in the case that the temperature difference between the inlet and outlet water temperatures of the exhaust gas recirculation EGR cooler exceeds a first temperature threshold, the second target opening degree of the second valve is calibrated. Figure 6 is a flow chart of another calibration method of a heat management system of an engine provided by the embodiment of the application, referring to Figure 6 The calibration method of the heat management system of the engine is suitable for the calibration when the small circulation state is adopted for circulation in the case that the temperature difference between the inlet and outlet water temperatures of the EGR cooler is too large in the micro-circulation state, and the calibration of the second target opening degree of the second valve comprises:

[0104] S411, control the engine to start from the cold state, idle for a set time to the first test working condition; in the first test working condition, control the first valve and the third valve to be closed.

[0105] Specifically, the engine can start idling from a cold state for a set time until a first test working condition is reached, where the first test working condition is a test working condition with a small engine speed and torque, and in the first test working condition, the engine speed is less than or equal to a first speed threshold, and the torque is less than or equal to a first torque threshold. Wherein, the first test working condition can be selected as the maximum heat dissipation point of the vehicle, and the first test working condition is selected in sections.

[0106] S412, in the first test working condition, the speed of the electronic water pump and / or the opening of the second valve in the first speed range is adjusted until the first test stop condition or the second test stop condition is met, and the test is stopped, and the opening of the second valve corresponding to the second test stop condition is taken as the second target opening of the second valve in the first test working condition, and the speed of the electronic water pump corresponding to the second test stop condition is taken as the first target speed of the electronic water pump in the first test working condition.

[0107] Wherein, in different first test working conditions, the engine speed is different and / or the torque is different. In each first test working condition, the speed of the electronic water pump in the first speed range is adjusted in order from small to large, and when any opening of the second valve at a lower speed of the electronic water pump can meet the first test stop condition or the second test stop condition, the test can be stopped, and the speed of the electronic water pump is no longer adjusted upward.

[0108] Wherein, the first test stop condition includes that the outlet water temperature reaches the first preset temperature later than at least one of the other conditions; the second test stop condition includes that the outlet water temperature reaches the first preset temperature earlier than the other conditions; and the other conditions include that the cylinder block water jacket temperature reaches a second preset temperature, the oil temperature reaches a third preset temperature, and the cylinder head wall surface temperature reaches a fourth preset temperature.

[0109] Optionally, the first preset temperature is 40℃, the second preset temperature is 120℃, the third preset temperature is 85℃, and the fourth preset temperature is 240℃.

[0110] In the case of meeting the first test stop condition, S413 is performed to increase the opening of the second valve and / or increase the speed of the electronic water pump; then return to S411 to control the engine to start from a cold state, idle for a set time to a first test working condition, until the second test stop condition is met.

[0111] In the case of meeting the second test condition, S414 is performed to increase the speed and torque of the engine, and then return to S411.

[0112] Optionally, in the embodiment, from low load to high load, the first test working condition, in each first test working condition, the speed of the electronic water pump and / or the opening of the second valve are adjusted in the first speed range until the first test stop condition or the second test stop condition is met, the test is stopped, and the opening of the second valve corresponding to the second test stop condition is taken as the second target opening of the second valve in the first test working condition, and the speed of the electronic water pump corresponding to the second test stop condition is taken as the first target speed in the first test working condition.

[0113] Specifically, in each first test working condition, the speed of the electronic water pump can be fixed first, and then the opening of the second valve is adjusted to determine the opening that can meet the first test stop condition or the second test stop condition, and the test is stopped. If the opening that meets the second test stop condition is determined, the opening is taken as the second target opening of the second valve in the first test working condition, and the fixed speed is determined as the target speed in the first test working condition. If the second valve reaches the maximum opening under the fixed speed of the electronic water pump and still does not meet the second test condition or can meet the first test stop condition, the speed of the electronic water pump can be increased, and the opening of the second valve is adjusted under the fixed speed after the increase according to the above process until the second test stop condition is met.

[0114] Figure 7 is the specific flow chart of the calibration when the EGR cooler inlet and outlet water temperature difference is too large and the small circulation state is used for circulation. Referring to Figure 7 The calibration method comprises:

[0115] The engine in the cold state is idled for 1 min and quickly raised to the first test working condition.

[0116] The external circulation water is closed (i.e., the first valve and the third valve are closed, and the second valve is opened), the electronic water pump is specified at a speed, and the engine is tested and operated from the first test working condition with low load.

[0117] The outlet water temperature, the cylinder block water jacket temperature, the oil temperature reaching the third preset temperature, the cylinder head wall surface temperature, and the EGR cooler inlet and outlet water temperature difference are monitored.

[0118] When the engine outlet water temperature rises to 40℃, the cylinder block water jacket temperature reaches 120℃, the cylinder head wall surface temperature reaches 240℃, or the oil temperature reaches 85℃, one of the four conditions is met, and the test is stopped.

[0119] If the outlet water temperature rises to 40℃ first, the opening of the second valve in the electronic temperature regulator meets the warm-up cooling requirement of this working condition, and the opening of the second valve is recorded.

[0120] The engine speed and load are increased to continue the test.

[0121] If the cylinder liner water jacket water temperature reaches 120℃, the cylinder head wall surface temperature reaches 240℃, or the oil temperature reaches 85℃ first, the opening degree of the second valve in the electronic thermostat does not meet the warm-up cooling requirements of this working condition.

[0122] Increase the opening degree of the second valve in the electronic thermostat and return to the engine idle running state under the normal temperature cold state. The engine is quickly raised to the first test working condition for 1 min.

[0123] Figure 8 is another flowchart of the calibration method of the engine thermal management system provided by the embodiment of the present application. The calibration method can be used for parameter calibration in a small cycle state, and reference is made to Figure 8 The calibration method of the engine thermal management system includes:

[0124] S510, control the engine to start from the cold state, idle running for a set time to the second test working condition; in the second test working condition, control the first valve and the third valve to be closed.

[0125] In the second test working condition, the engine speed is greater than the first speed threshold and less than or equal to the second speed threshold, and the engine torque is greater than the first torque threshold and less than or equal to the second torque threshold.

[0126] S520, in the second test working condition, adjust the speed of the electronic water pump in the second speed interval and / or the second valve in the second speed interval within the second speed interval until the third test stop condition or the fourth test stop condition is met, stop the test, and the opening degree of the second valve corresponding to the fourth test stop condition is taken as the second target opening degree of the second valve in the second test working condition. The corresponding electronic water pump is taken as the second target speed in the second test working condition.

[0127] In the second test working condition, the engine speed is greater than the first speed threshold and less than or equal to the second speed threshold, and the engine torque is greater than the first torque threshold and less than or equal to the second torque threshold.

[0128] In the second test working condition, the engine speed is greater than the first speed threshold and less than or equal to the second speed threshold, and the engine torque is greater than the first torque threshold and less than or equal to the second torque threshold.

[0129] If the third test stop condition is met, S530 is performed, the second valve opening is increased, and / or the rotation speed of the electronic water pump is increased, and the process returns to S510, in which the engine is controlled to run at idle speed from the cold state for a set time to the second test operating condition until the fourth test stop condition is met.

[0130] Optionally, in the embodiment, the second test operating condition from low load to high load, the rotation speed of the electronic water pump in the second rotation speed range and / or the second valve are adjusted in the second rotation speed range in each second test operating condition until the third test stop condition or the fourth test stop condition is met, the test is stopped, and the opening of the second valve corresponding to the fourth test stop condition is taken as the second target opening of the second valve in the second test operating condition, and the rotation speed of the corresponding electronic water pump is taken as the second target rotation speed in the second test operating condition.

[0131] If the fourth test condition is met, S540 is performed, the rotation speed and torque of the engine are increased, and then the process returns to S510.

[0132] The calibration method of the thermal management system of the embodiment is similar to that of the above-mentioned embodiments, and will not be described here.

[0133] Figure 9 is a specific flow chart of calibration when the small cycle state is cycled. Referring to Figure 9 The calibration method comprises:

[0134] The engine in the cold state at room temperature runs at idle speed for 1 min and is quickly raised to the second test operating condition.

[0135] The external circulation water is closed (i.e., the first valve and the third valve are closed, and the second valve is opened), the electronic water pump is set to a rotation speed, and the engine is tested and run from the second test operating condition with low load.

[0136] The outlet water temperature, the cylinder block water jacket temperature, the oil temperature reaching the third preset temperature, the cylinder head wall surface temperature, and the EGR cooler inlet and outlet water temperature difference are monitored.

[0137] When the engine outlet water temperature rises to 80℃, the cylinder block water jacket temperature reaches 160℃, the cylinder head wall surface temperature reaches 320℃, or the oil temperature reaches 105℃, one of the four conditions is met, and the test is stopped.

[0138] If the outlet water temperature rises to 80℃ first, the opening of the second valve in the electronic thermostat meets the warm-up cooling requirement of this operating condition, and the opening of the second valve is recorded.

[0139] The engine rotation speed and load are increased to continue the test.

[0140] If the water jacket temperature of the cylinder body reaches 160℃, the cylinder head wall surface temperature reaches 320℃, or the oil temperature reaches 105℃ first, the opening degree of the second valve in the electronic thermostat does not meet the warm-up cooling requirement of this working condition.

[0141] Increase the opening degree of the second valve in the electronic thermostat and return to the engine idle running state under the normal temperature cold state to quickly raise to the second test working condition.

[0142] Figure 10 is another flowchart of a calibration method of an engine thermal management system provided by an embodiment of the present application, which can be used for parameter calibration in the hot engine mode, referring to Figure 10 The calibration method of the engine thermal management system comprises:

[0143] S610, in the case that the first valve and the third valve are fully open and the second valve is closed, calibrate the target outlet water temperature corresponding to each third test working condition; the target outlet water temperature meets the lowest fuel consumption in the third test working condition.

[0144] The engine speed in the third test working condition is greater than the second speed threshold and less than or equal to the third speed threshold, and the torque is greater than the second torque threshold and less than or equal to the third torque threshold.

[0145] Optionally, the engine outlet water temperature sensor test temperature points are set in the normal temperature range in the hot engine mode, in which the first preset gradient is set, and each first preset gradient corresponds to an outlet water temperature. According to the third test working condition, the outlet water temperature corresponding to each first preset gradient ensures that the inlet and outlet water temperature difference of the engine is in the preset temperature difference range. In some embodiments, the outlet water temperature corresponding to the minimum fuel consumption in the case that the inlet and outlet water temperature difference is in the preset temperature difference range is determined as the corresponding target outlet water temperature. In other embodiments, a second preset gradient can also be set in the preset temperature difference range, each second preset gradient corresponds to an inlet and outlet water temperature difference, the engine is stably run for a predetermined fixed time under each second preset gradient, the engine instantaneous fuel consumption data of the same outlet water temperature under different inlet and outlet water temperature differences is recorded, and the target outlet water temperature in the third test working condition is determined according to the lowest value of the fuel consumption rate of each working condition.

[0146] For example, the normal temperature range in the hot engine mode is set to 80℃-110℃, and each gradient is 5℃. According to the test working condition, each temperature point ensures that the inlet and outlet water temperature difference is 8℃-12℃, each gradient is 2℃, the temperature fluctuation is ±0.5℃, the engine is stably run for 30S, and the engine instantaneous fuel consumption data of each temperature test point is recorded, and the target outlet water temperature in the third test working condition is determined according to the lowest value of the fuel consumption rate of each working condition.

[0147] S620, according to the third test working condition and the corresponding target outlet water temperature, adjusting the opening degree of the first valve and the third valve at the first set rotating speed of the electronic water pump until the outlet water temperature reaches the corresponding target outlet water temperature, and taking the opening degree of the first valve and the opening degree of the third valve when the target outlet water temperature is reached as the first target opening degree of the first valve and the third target opening degree of the third valve respectively under the third test working condition.

[0148] The first set rotating speed can be a 100% duty cycle rotating speed.

[0149] After the target outlet water temperature corresponding to the third test working condition is determined, the opening degree of the first valve and the third valve is adjusted at the third set rotating speed of the electronic water pump until the outlet water temperature reaches the target outlet water temperature corresponding to the third test working condition. Since the target outlet water temperature satisfies the lowest fuel consumption under the corresponding third test working condition, the first target opening degree and the second target opening degree determined can satisfy the lowest fuel consumption under the corresponding third test working condition, so that the optimal fuel consumption temperature control is realized under the calibration parameters obtained.

[0150] Reference Figure 2 Optionally, the thermal management system further comprises a retarder, a fourth valve and a fifth valve; and the large circulation state comprises a retarder working mode. Figure 11 is a flowchart of another calibration method of the thermal management system of the engine provided by the embodiment of the present application, which can be used for parameter calibration in the retarder working mode, and reference Figure 11 The calibration method of the thermal management system of the engine comprises:

[0151] S710, in the case that the first valve and the third valve are fully opened, the second valve is closed, the fourth valve is closed, and the fifth valve is fully opened, calibrating the target outlet water temperature corresponding to each fourth test working condition; the target outlet water temperature satisfies the lowest fuel consumption under the fourth test working condition.

[0152] S720, according to the fourth test working condition and the corresponding target outlet water temperature, adjusting the opening degree of the first valve and the third valve at the second set rotating speed of the electronic water pump until the outlet water temperature reaches the corresponding target outlet water temperature, and taking the opening degree of the first valve and the opening degree of the third valve when the target outlet water temperature is reached as the first target opening degree of the first valve and the third target opening degree of the third valve respectively under the fourth test working condition.

[0153] The second set rotating speed can be a 100% duty cycle rotating speed.

[0154] The calibration method of the embodiment, and Figure 10 The calibration method in the thermal engine mode is similar, and the only difference is that the coolant passes through the retarder in the retarder working mode, and the coolant passes through the coolant bypass branch in the thermal engine mode. Here, no longer be described.

[0155] It should be understood that the various forms of flow shown above can be used to reorder, add, or remove steps. For example, the steps described in the present application can be performed in parallel, in series, or in a different order, as long as the desired results of the technical solutions of the present application can be achieved, which are not limited herein.

[0156] The above detailed description does not constitute a limitation on the protection scope of the present application. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent replacements, and improvements made within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A thermal management system of an engine, characterized by, The heat management system comprises: a control module, an electronic water pump and an electronic thermostat; the electronic thermostat comprises a plurality of inlets, a plurality of outlets, a first valve, a second valve and a third valve, wherein the plurality of inlets comprises a macro circulation inlet and a micro circulation inlet, and the first valve is arranged at the macro circulation inlet; the plurality of outlets comprises a micro circulation outlet, a small circulation outlet and a macro circulation outlet, the micro circulation outlet and the water pump inlet of the electronic water pump are connected through a small circulation bypass branch, the second valve is arranged at the small circulation outlet, and the third valve is arranged at the macro circulation outlet, and a radiator is arranged between the third valve and the water pump inlet; the control module is connected with the electronic thermostat, and is configured to control the circulation state of the heat management system according to at least the engine water temperature, and control the first valve, the second valve and the third valve to be closed in the micro circulation state, control the first valve and the third valve to be closed and the second valve to be opened in the small circulation state, and control the first valve and the third valve to be opened and the second valve to be closed in the macro circulation state; wherein the water pump outlet of the electronic water pump is communicated with at least one of the micro circulation inlet in the micro circulation state, the small circulation state and the macro circulation state.

2. The thermal management system of an engine according to claim 1, characterized by, The control module is further connected with the electronic water pump, and the control module is further configured to control the electronic water pump to operate at a first rotating speed in the micro circulation state, control the electronic water pump to operate at a second rotating speed in the small circulation state, and control the electronic water pump to operate at a third rotating speed in the macro circulation state, wherein the second rotating speed is greater than the first rotating speed and less than the third rotating speed. The heat management system further comprises a retarder, a fourth valve and a fifth valve; 3. The thermal management system of an engine according to claim 1, characterized by, the retarder is arranged between the water pump outlet and the macro circulation inlet, the fourth valve connects the outlet of the retarder through a retarder bypass branch, and is configured to control the communication state between the water pump outlet and the outlet of the retarder, and the fifth valve is configured to control the communication state between the water pump outlet and the inlet of the retarder, and the outlet of the retarder is connected with the first valve; the control module is connected with the fourth valve and the fifth valve, and the macro circulation state comprises at least one of a thermal engine mode, a retarder working mode and a failure protection mode; the control module is further configured to control the fourth valve to be opened and the fifth valve to be closed in the micro circulation state, the small circulation state, the thermal engine mode and the failure protection mode, and control the fourth valve to be closed and the fifth valve to be opened in the retarder working mode. The heat management method is applied to the heat management system of any one of claims 1-3, and the heat management method comprises:

4. A method of thermal management of an engine, characterized by, ​ The circulation state of the thermal management system is controlled according to at least the engine water temperature, and in the micro circulation state, the first valve, the second valve and the third valve are controlled to be closed; in the small circulation state, the first valve and the third valve are controlled to be closed, and the second valve is controlled to be opened; in the large circulation state, the first valve and the third valve are controlled to be opened, and the second valve is controlled to be closed; wherein in the micro circulation state, the small circulation state and the large circulation state, the water pump outlet of the electronic water pump is in communication with the micro-small circulation inlet.

5. The method of thermal management of an engine according to claim 4, characterized in that, Further comprising: in the micro circulation state, the electronic water pump is controlled to operate at a first rotating speed; in the small circulation state, the electronic water pump is controlled to operate at a second rotating speed; in the large circulation state, the electronic water pump is controlled to operate at a third rotating speed, the second rotating speed is greater than the first rotating speed and less than the third rotating speed.

6. The method of thermal management of an engine according to claim 4, characterized in that, The thermal management system further comprises a retarder, a fourth valve and a fifth valve; the large circulation state comprises at least one of a thermal engine mode, a retarder working mode and a failure protection mode; the thermal management method further comprises: in the micro circulation state, the small circulation state, the thermal engine mode and the failure protection mode, the fourth valve is controlled to be opened, and the fifth valve is controlled to be closed; and in the retarder working mode, the fourth valve is controlled to be closed, and the fifth valve is controlled to be opened.

7. The method of thermal management of an engine according to claim 6, characterized in that, The at least according to the engine water temperature control the circulation state of the thermal management system comprises: in the case of determining that the retarder does not need to work, in the case of the engine water temperature being in a first temperature interval, according to the engine working condition, the thermal management system is controlled to work in the micro circulation state or the small circulation state; in the case of the engine water temperature being in a second temperature interval, the thermal management system is controlled to work in the small circulation state; in the case of the engine water temperature being in a third temperature interval, the thermal management system is controlled to work in the thermal engine mode; in the case of the duration of the engine water temperature being in a fourth temperature interval exceeding a preset duration threshold, the thermal management system is controlled to work in the failure protection mode; wherein the temperatures of the first temperature interval, the second temperature interval, the third temperature interval and the fourth temperature interval increase in turn; the opening degree of the first valve in the thermal engine mode is less than or equal to the opening degree of the first valve in the failure protection mode, and / or the opening degree of the third valve in the thermal engine mode is less than or equal to the opening degree of the third valve in the failure protection mode; in the case of determining that the retarder needs to work, the thermal management system is controlled to work in the retarder working mode.

8. The method of thermal management of an engine according to any one of claims 4-7, characterized in that, The at least according to the engine water temperature control the circulation state of the thermal management system comprises: According to the engine water temperature, engine working condition and preset corresponding relationship control the valve opening degree of the electronic thermostat and the rotating speed of the electronic water pump; the engine working condition includes the rotating speed and torque of the engine; the preset corresponding relationship includes the corresponding relationship between the engine water temperature, the engine working condition and the valve opening degree of the electronic thermostat, the rotating speed of the electronic water pump; the valve opening degree of the electronic thermostat includes the opening degree of the third valve, the fourth valve and the fifth valve; Wherein, the preset corresponding relationship is obtained based on the bench test of the engine.

9. A method of calibrating a thermal management system of an engine, characterized in that, For calibrating the thermal management system of the engine of any one of claims 1-3, the calibration method comprises: Based on the bench test of the engine, at least according to the outflow temperature, cylinder block water jacket temperature, oil temperature and cylinder head wall temperature and oil consumption of the engine, the corresponding relationship between the outflow temperature and engine working condition and the valve opening degree of the electronic thermostat, the rotating speed of the electronic water pump is determined as the preset corresponding relationship of calibration.

10. The method of calibrating a thermal management system of claim 9, wherein, The corresponding relationship between the outflow temperature and engine working condition and the valve opening degree of the electronic thermostat, the rotating speed of the electronic water pump is determined based on the bench test of the engine, at least according to the outflow temperature, cylinder block water jacket temperature, oil temperature and cylinder head wall temperature and oil consumption of the engine, as the preset corresponding relationship of calibration, comprising: In the thermal management system, in the microcirculation state, the first valve, the second valve and the third valve are all closed, and the temperature difference between the inlet and outlet water of the exhaust gas recirculation EGR cooler exceeds the first temperature threshold, the second target opening degree of the second valve is calibrated; Wherein, calibrating the second target opening degree of the second valve comprises: Control the engine to run at idle speed for a set time from cold state to first test working condition; in the first test working condition, control the first valve and the third valve to be closed; From low load to high load, in each first test working condition, adjust the rotating speed of the electronic water pump and / or the opening degree of the second valve in the first rotating speed range until the first test stop condition or the second test stop condition is met, stop the test, and the opening degree of the second valve corresponding to the second test stop condition is taken as the second target opening degree of the second valve in the first test working condition, and the corresponding rotating speed of the electronic water pump is taken as the first target rotating speed in the first test working condition; In the case where the first test stop condition is reached, increase the opening degree of the second valve and / or increase the rotating speed of the electronic water pump, and return to control the engine to run at idle speed for a set time from cold state to first test working condition until the second test stop condition is met; Wherein, the first test stop condition includes that the outflow temperature reaches the first preset temperature later than at least one of the other conditions; the second test stop condition includes that the outflow temperature reaches the first preset temperature earlier than the other conditions; The other conditions include that the cylinder jacket water temperature reaches a second preset temperature, the oil temperature reaches a third preset temperature, and the cylinder head wall surface temperature reaches a fourth preset temperature.

11. The method of calibrating a thermal management system of claim 9, wherein, The preset corresponding relationship is calibrated based on the bench test of the engine, and is determined according to at least multiple parameters of the engine, including the outlet water temperature, the cylinder jacket water temperature, the oil temperature, the cylinder head wall surface temperature, and the fuel consumption, and the engine operating condition, and the corresponding relationship between the opening degree of the valve of the electronic thermostat and the rotating speed of the electronic water pump. The engine is controlled to start from a cold state, run at an idle speed for a set time, and reach a second test operating condition; in the second test operating condition, the first valve and the third valve are controlled to be closed; In the second test operating condition from a low load to a high load, the rotating speed of the electronic water pump in a second rotating speed range and / or the second valve are adjusted in each second test operating condition in the second rotating speed range until a third test stop condition or a fourth test stop condition is met, the test is stopped, and the opening degree of the second valve corresponding to the fourth test stop condition is taken as a second target opening degree of the second valve in the second test operating condition, and the corresponding electronic water pump is taken as a second target rotating speed in the second test operating condition; In the case where the third test stop condition is met, the opening degree of the second valve is increased, and / or the rotating speed of the electronic water pump is increased, and the engine is controlled to start from a cold state, run at an idle speed for a set time, and reach a second test operating condition until the fourth test stop condition is met; The third test stop condition includes that the outlet water temperature reaches a fifth preset temperature later than at least one other condition, and the fourth test stop condition includes that the outlet water temperature reaches the fifth preset temperature earlier than the other conditions. The other conditions include that the cylinder jacket water temperature reaches a sixth preset temperature, the oil temperature reaches a seventh preset temperature, and the cylinder head wall surface temperature reaches an eighth preset temperature.

12. The method of calibrating a thermal management system of claim 9, wherein, The preset corresponding relationship is calibrated based on the bench test of the engine, and is determined according to at least multiple parameters of the engine, including the outlet water temperature, the cylinder jacket water temperature, the oil temperature, the cylinder head wall surface temperature, and the fuel consumption, and the engine operating condition, and the corresponding relationship between the opening degree of the valve of the electronic thermostat and the rotating speed of the electronic water pump. In the case where the first valve and the third valve are fully open and the second valve is closed, a target outlet water temperature corresponding to each third test operating condition is calibrated; the target outlet water temperature satisfies that the fuel consumption is the lowest in the third test operating condition; According to the third test operating condition and the corresponding target outlet water temperature, the opening degree of the first valve and the opening degree of the third valve are adjusted at a first set rotating speed of the electronic water pump until the outlet water temperature reaches the corresponding target outlet water temperature, and the opening degree of the first valve and the opening degree of the third valve when the target outlet water temperature is reached are taken as a first target opening degree of the first valve and a third target opening degree of the third valve in the third test operating condition, respectively.

13. The method of calibrating a thermal management system of claim 9, wherein, The heat management system further comprises a retarder, a fourth valve and a fifth valve; the large circulation state comprises a retarder working mode; based on the bench test of the engine, at least according to multiple parameters of the water outlet temperature, the cylinder block water jacket temperature, the oil temperature and the cylinder head wall surface temperature and the oil consumption of the engine, the corresponding relationship between the water outlet temperature and the engine working condition, the valve opening degree of the electronic thermostat and the rotating speed of the electronic water pump is determined as a preset corresponding relationship of calibration, comprising: In the case that the first valve and the third valve are fully opened, the second valve is closed, the fourth valve is closed and the fifth valve is fully opened, a target water outlet temperature corresponding to each fourth test working condition is calibrated; the target water outlet temperature satisfies the lowest oil consumption in the fourth test working condition; According to the fourth test working condition and the corresponding target water outlet temperature, the opening degrees of the first valve and the third valve are adjusted at the second set rotating speed of the electronic water pump until the water outlet temperature reaches the corresponding target water outlet temperature; the opening degrees of the first valve and the third valve when the target water outlet temperature is reached are respectively taken as the first target opening degree of the first valve and the third target opening degree of the third valve under the fourth test working condition.

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