Cooling system of natural gas engine and control method thereof

Abstract

The invention discloses a cooling system of a natural gas engine and a control method thereof, and the method comprises the following steps: after the natural gas engine is started, monitoring the natural gas temperature, the gas inlet temperature and the engine water outlet temperature of the cooling system in real time; based on the natural gas temperature, the state of a first control valve is controlled so as to adjust a water path of a cooling system to heat natural gas in a vaporizer; based on the air inlet temperature, the state of a second control valve is controlled so as to adjust a water path of the cooling system to cool waste gas in the EGR cooler; and the state of the third control valve is controlled based on the engine outlet water temperature so as to adjust a water path of the cooling system to cool cooling water of the cooling system. According to the method, control valves corresponding to a vaporizer, an EGR cooler and a radiator are controlled to adjust a water path of a cooling system, so that the natural gas temperature, the gas inlet temperature and the engine water outlet temperature are maintained within a reasonable range, and accurate control over the natural gas temperature in the natural gas engine is achieved.

Description

Technical Field

[0001] The present application relates to the field of natural gas engines, and in particular to a cooling system of a natural gas engine and a control method thereof. Background Art

[0002] The main component of natural gas engine fuel is methane. Compared with gasoline and other fuels, it emits less harmful gases after combustion and is more environmentally friendly. According to the fuel state, it can be divided into compressed natural gas (CNG) engines and liquefied natural gas (LNG) engines. CNG is stored in high-pressure gas cylinders after compression and has a high working pressure. LNG is stored after liquefaction of natural gas and has a high storage density. LNG engines (LNG gas engines for short) are currently widely used in buses, heavy trucks and other vehicle fields, reducing vehicle exhaust pollution and reducing operating costs.

[0003] The natural gas temperature of the LNG engine needs to be controlled within a certain range, neither too high nor too low. When the natural gas temperature is low, the combustion reaction speed will slow down. This will cause the fuel to not burn fully, affecting the power and economy of the engine. When the natural gas temperature is too high, it is easy for the terminal mixture in the combustion chamber to ignite and burn due to high temperature and high pressure before the flame front arrives, causing detonation. Excessive gas temperature will also increase the heat load of components such as pistons and valves, generate thermal stress, and damage the engine.

[0004] Therefore, how to accurately control the natural gas temperature of the LNG gas generator has become an urgent problem to be solved. Summary of the invention

[0005] The present application provides a cooling system for a natural gas engine and a control method thereof, the purpose of which is to accurately control the natural gas temperature of the LNG gas engine.

[0006] In order to achieve the above objectives, this application provides the following technical solutions:

[0007] A cooling system for a natural gas engine, comprising:

[0008] Water pump, components to be cooled, carburetor, EGR cooler, radiator, temperature monitoring module and water circuit control module;

[0009] The water pump is used to provide cooling water to the water circuit of the cooling system;

[0010] The temperature monitoring module includes a first sensor, a second sensor and a third sensor; the first sensor is deployed on the carburetor to monitor the natural gas temperature in the carburetor; the second sensor is deployed on the EGR cooler to monitor the intake air temperature of the EGR cooler; the third sensor is deployed on the water path where the component to be cooled is located to monitor the engine outlet water temperature;

[0011] The water circuit control module includes a first control valve, a second control valve and a third control valve; the first control valve is deployed on the water circuit where the vaporizer is located, and is used to control the water circuit where the vaporizer is located to participate in the water circulation of the cooling system; the second control valve is deployed on the water circuit where the EGR cooler is located, and is used to control the water circuit where the EGR cooler is located to participate in the water circulation of the cooling system; the third control valve is deployed on the water circuit where the radiator is located, and is used to control the water circuit where the radiator is located to participate in the water circulation of the cooling system.

[0012] Optionally, when the natural gas temperature is lower than a first calibration temperature, the first control valve is in an open state, and the water circuit where the vaporizer is located participates in the water circulation of the cooling system, so that the cooling water heats the natural gas in the vaporizer; when the natural gas temperature is higher than a second calibration temperature, the first control valve is in a closed state, and the water circuit where the vaporizer is located does not participate in the water circulation of the cooling system; the first calibration temperature is lower than the second calibration temperature.

[0013] Optionally, when the intake air temperature is greater than or equal to the third calibration temperature, the second control valve is in an open state, and the water circuit where the EGR cooler is located participates in the water circulation of the cooling system, so that the cooling water cools the exhaust gas in the EGR cooler; when the intake air temperature is lower than the third calibration temperature, the second control valve is in a closed state, and the water circuit where the EGR cooler is located does not participate in the water circulation of the cooling system.

[0014] Optionally, when the engine outlet water temperature is greater than a fourth calibrated temperature, the third control valve is controlled to be in an open state, and the water circuit where the radiator is located participates in the water circulation of the cooling system, so that the radiator cools the cooling water; when the engine outlet water temperature is less than or equal to the fourth calibrated temperature, the third control valve is controlled to be in a closed state, and the water circuit where the radiator is located does not participate in the water circulation of the cooling system.

[0015] A control method is applied to the above cooling system, the method comprising:

[0016] When the natural gas engine is started, the natural gas temperature, the intake air temperature and the engine outlet water temperature of the cooling system are monitored in real time;

[0017] Based on the natural gas temperature, controlling the state of the first control valve to adjust the water path of the cooling system to heat the natural gas in the vaporizer;

[0018] Based on the intake air temperature, controlling the state of the second control valve to adjust the water path of the cooling system to cool the exhaust gas in the EGR cooler;

[0019] Based on the engine outlet water temperature, the state of the third control valve is controlled to adjust the water path of the cooling system to cool the cooling water of the cooling system.

[0020] Optionally, based on the natural gas temperature, controlling the state of the first control valve to adjust the water circuit of the cooling system to heat the natural gas in the vaporizer includes:

[0021] When the temperature of the natural gas is lower than the first calibration temperature, the first control valve is controlled to be in an open state, triggering the water path where the vaporizer in the cooling system is located to participate in the water circulation of the cooling system, so that the cooling water of the cooling system heats the natural gas in the vaporizer;

[0022] When the natural gas temperature is greater than the second calibration temperature, the first control valve is controlled to be in a closed state, triggering the water circuit where the vaporizer is located not to participate in the water circulation of the cooling system; the first calibration temperature is lower than the second calibration temperature.

[0023] Optionally, based on the intake air temperature, controlling the state of the second control valve to adjust the water circuit of the cooling system to cool the exhaust gas in the EGR cooler includes:

[0024] When the intake air temperature is greater than or equal to the third calibration temperature, the second control valve is controlled to be in an open state, triggering the water path where the EGR cooler in the cooling system is located to participate in the water circulation of the cooling system, so that the cooling water of the cooling system cools down the exhaust gas in the EGR cooler;

[0025] When the intake air temperature is lower than the third calibrated temperature, the second control valve is controlled to be in a closed state, so that the water path where the EGR cooler is located does not participate in the water circulation of the cooling system.

[0026] Optionally, based on the engine outlet water temperature, controlling the state of the third control valve to adjust the water path of the cooling system to cool the cooling water of the cooling system includes:

[0027] When the engine outlet water temperature is greater than a fourth calibration temperature, the third control valve is controlled to be in an open state, triggering the water path where the radiator in the cooling system is located to participate in the water circulation of the cooling system, so that the radiator cools the cooling water;

[0028] When the engine outlet water temperature is less than or equal to the fourth calibrated temperature, the third control valve is controlled to be in a closed state, which triggers the water path where the radiator is located to not participate in the water circulation of the cooling system.

[0029] Optionally, the control method further includes:

[0030] When the natural gas temperature is greater than or equal to the first calibration temperature and less than or equal to the second calibration temperature, the opening of the first control valve in the open state is controlled to adjust the heating rate of the natural gas in the vaporizer; wherein the opening is proportional to the heating rate.

[0031] A vehicle comprises: a processor, a memory and a bus, wherein the processor is connected to the memory via the bus, the memory is used to store a program, and the processor is used to run the program, wherein the control method described above is executed when the program is run.

[0032] The technical solution provided by the present application can cut off the water circuit of the EGR cooler when the natural gas temperature is low and the intake air temperature is low (i.e., the intake air temperature is less than the third calibration temperature), so that the water circuit where the EGR cooler is located does not participate in the water circulation of the cooling system, thereby reducing the actual circulating water capacity in the water circuit of the cooling system, increasing the heating rate of the natural gas temperature, shortening the heating waiting time of the liquefied natural gas, and closing the water circuit of the vaporizer in a high temperature state (i.e., the natural gas temperature is greater than or equal to the second calibration temperature) (i.e., the water circuit where the vaporizer is located does not participate in the water circulation of the cooling system), preventing the natural gas temperature from being too high, thereby controlling the natural gas temperature within a reasonable range. In addition, the opening of the second control valve can be controlled according to the intake air temperature, so that the intake air temperature is maintained within a reasonable range, reducing the risk of misfire or detonation. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0034] Figure 1 A schematic diagram of the architecture of a cooling system for a natural gas engine provided in an embodiment of the present application;

[0035] Figure 2 A schematic diagram of a control method provided in an embodiment of the present application;

[0036] Figure 3 A schematic diagram of a water circuit operation of a cooling system provided in an embodiment of the present application;

[0037] Figure 4 A schematic diagram of the water circuit operation of another cooling system provided in an embodiment of the present application;

[0038] Figure 5 A schematic diagram of the water circuit operation of another cooling system provided in an embodiment of the present application;

[0039] Figure 6 A schematic diagram of the water circuit operation of another cooling system provided in an embodiment of the present application;

[0040] Figure 7 A schematic diagram of another control method provided in an embodiment of the present application. DETAILED DESCRIPTION

[0041] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0042] In this application, relational terms such as first and second, etc. are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. The terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of more restrictions, the elements defined by the sentence "comprise one..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0043] like Figure 1 , which is a schematic diagram of the architecture of a cooling system for a natural gas engine according to an embodiment of the present application. The cooling system for the natural gas engine can be applied to a vehicle and includes the following components.

[0044] A water pump 1, components to be cooled (including an oil cooler 2, an engine body water jacket 3, a cylinder head water jacket 4 and a water outlet pipe 5), a carburetor 6, an EGR cooler 7, a radiator 9, a temperature monitoring module (including a first sensor 11, a second sensor 12 and a third sensor 10) and a water circuit control module (including a first control valve 13, a second control valve 14 and a third control valve 8).

[0045] In some examples, the first sensor 11 , the second sensor 12 , and the third sensor 10 are of the type of temperature sensors.

[0046] In some examples, the first sensor 11 may be considered a natural gas temperature sensor (or simply a gas temperature sensor), the second sensor 12 may be considered an intake air temperature sensor, and the third sensor 10 may be considered an engine water temperature sensor (or simply a water temperature sensor).

[0047] In some examples, the first control valve 13 may be considered as a carburetor water circuit control valve, the second control valve 14 may be considered as an EGR cooler water circuit control valve, and the third control valve 8 may be considered as a water outlet control valve.

[0048] The so-called parts to be cooled can be understood as parts that generate heat and need to be cooled during the operation of the engine.

[0049] The so-called vaporizer 6 is specifically used to heat the liquid natural gas into a gas state through the cooling water of the engine for combustion in the natural gas engine.

[0050] The so-called EGR cooler 7 specifically refers to a cooling device of an EGR (Exhaust Gas Recirculation) system.

[0051] The water pump 1 is used to provide cooling water for the water circuit of the cooling system. Generally speaking, the water circuit of the cooling system is a circulating water circuit.

[0052] The first sensor 11 is disposed on the vaporizer 6 and is used to monitor the temperature of the natural gas in the vaporizer 6 .

[0053] In a possible implementation, the first sensor 11 may be installed at a position before the end of the carburetor 6 is mixed with the fresh air.

[0054] The second sensor 12 is disposed on the EGR cooler 7 and is used to monitor the intake air temperature of the EGR cooler 7 .

[0055] In a possible implementation, the second sensor 12 may be installed at the air inlet of the EGR cooler 7 .

[0056] The third sensor 10 is disposed in the water path where the components to be cooled are located, and is used to monitor the engine outlet water temperature.

[0057] In a possible implementation manner, the third sensor 10 is installed on the waterway where the component to be cooled is located and passes through the location of the component to be cooled.

[0058] The first control valve 13 is disposed on the water path where the vaporizer 6 is located, and is used to control the water path where the vaporizer 6 is located to participate in the water circulation of the cooling system.

[0059] In a possible implementation, the first control valve 13 may be installed at an upstream position of a corresponding area of ​​the vaporizer 6 in the water path where the vaporizer 6 is located.

[0060] The second control valve 14 is disposed on the water path where the EGR cooler 7 is located, and is used to control the water path where the EGR cooler 7 is located to participate in the water circulation of the cooling system.

[0061] In a possible implementation manner, the second control valve 14 may be installed at an upstream position of a region corresponding to the EGR cooler 7 in the water path where the EGR cooler 7 is located.

[0062] The third control valve 8 is disposed on the water path where the radiator 9 is located, and is used to control the water path where the radiator 9 is located to participate in the water circulation of the cooling system.

[0063] In a possible implementation, one end of the third control valve 8 is connected to the water outlet pipe, and the other end is respectively connected to the water pump 1 (so that the cooling water can directly flow back to the water pump 1) and the radiator 9 (so that the cooling water flows back to the water pump 1 after passing through the radiator 9).

[0064] Optionally, when the natural gas temperature is lower than the first calibration temperature, the first control valve 13 is in an open state, and the water circuit where the vaporizer 6 is located participates in the water circulation of the cooling system, so that the cooling water heats the natural gas in the vaporizer 6; when the natural gas temperature is higher than the second calibration temperature, the first control valve 13 is in a closed state, and the water circuit where the vaporizer 6 is located does not participate in the water circulation of the cooling system; the first calibration temperature is lower than the second calibration temperature.

[0065] In some examples, when the natural gas temperature is less than the first calibrated temperature, the second control valve 14 can be placed in a closed state so that the water circuit where the EGR cooler 7 is located does not participate in the water circulation of the cooling system, resulting in a reduction in the operating water capacity in the cooling system, thereby increasing the heating rate of the cooling water temperature (i.e., the engine outlet water temperature).

[0066] It should be noted that when the first control valve 13 is in the open state, the opening of the first control valve 13 can be adjusted according to the natural gas temperature. Generally speaking, the lower the natural gas temperature, the larger the opening of the first control valve 13, so that the heating rate of the natural gas in the vaporizer 6 is increased, and the higher the natural gas temperature, the smaller the opening of the first control valve 13, so that the heating rate of the natural gas in the vaporizer 6 is decreased, thereby avoiding the heating rate of the natural gas in the vaporizer 6 being too fast.

[0067] Optionally, when the intake air temperature is greater than or equal to the third calibration temperature, the second control valve 14 is in an open state, and the water circuit where the EGR cooler 7 is located participates in the water circulation of the cooling system, so that the cooling water cools the exhaust gas in the EGR cooler 7; when the intake air temperature is lower than the third calibration temperature, the second control valve 14 is in a closed state, and the water circuit where the EGR cooler 7 is located does not participate in the water circulation of the cooling system.

[0068] It should be noted that, if the intake air temperature is greater than or equal to the third calibration temperature, it can be determined that the temperature of the exhaust gas in the EGR cooler 7 is relatively high, and cooling water is required to cool the exhaust gas.

[0069] Optionally, when the engine outlet water temperature is greater than a fourth calibration temperature, the third control valve 8 is controlled to be in an open state, and the water circuit where the radiator 9 is located participates in the water circulation of the cooling system, so that the radiator 9 cools the cooling water; when the engine outlet water temperature is less than or equal to the fourth calibration temperature, the third control valve 8 is controlled to be in a closed state, and the water circuit where the radiator 9 is located does not participate in the water circulation of the cooling system.

[0070] It should be noted that, if the engine outlet water temperature is greater than the fourth calibrated temperature, it can be determined that the temperature of the cooling water is relatively high, and the radiator 9 needs to be used to cool the cooling water.

[0071] In some examples, a schematic diagram of the water circuit operation of the cooling system of a natural gas engine can be found in Figure 3-Figure 6 As shown (the waterway represented by the dotted line is blocked or disconnected).

[0072] Specifically, when the natural gas temperature is low (the natural gas temperature is less than the first calibration temperature), the EGR cooler 7 does not work (the water path where the EGR cooler 7 is located does not participate in the water circulation of the cooling system), and the cooling water is in a small circulation (the water path where the radiator 9 is located does not participate in the water circulation of the cooling system), the water path of the cooling system is as follows: Figure 3 shown.

[0073] Specifically, when the natural gas temperature is low (the natural gas temperature is lower than the first calibration temperature), the EGR cooler 7 is working (the water path where the EGR cooler 7 is located participates in the water circulation of the cooling system), and the cooling water is in a small circulation (the water path where the radiator 9 is located does not participate in the water circulation of the cooling system), the water path of the cooling system is as follows: Figure 4 shown.

[0074] Specifically, when the natural gas temperature is high (the natural gas temperature is greater than or equal to the second calibration temperature), the EGR cooler 7 does not work (the water path where the EGR cooler 7 is located does not participate in the water circulation of the cooling system), and the cooling water is in a large circulation (the water path where the radiator 9 is located participates in the water circulation of the cooling system), the water path of the cooling system is as follows: Figure 5 shown.

[0075] Specifically, when the natural gas temperature is high (the natural gas temperature is greater than or equal to the second calibration temperature), the EGR cooler 7 is working (the water path where the EGR cooler 7 is located participates in the water circulation of the cooling system), and the cooling water is circulating (the water path where the radiator 9 is located participates in the water circulation of the cooling system), the water path of the cooling system is as follows: Figure 6 shown.

[0076] The above-mentioned components can cut off the water circuit of the EGR cooler when the natural gas temperature is low and the intake air temperature is low (i.e., the intake air temperature is less than the third calibration temperature), so that the water circuit of the EGR cooler does not participate in the water circulation of the cooling system, so the actual circulating water capacity in the water circuit of the cooling system is reduced, the heating rate of the natural gas temperature is increased, and the heating waiting time of the liquefied natural gas is shortened. In the high temperature state (i.e., the natural gas temperature is greater than or equal to the second calibration temperature), the water circuit of the vaporizer is closed (i.e., the water circuit of the vaporizer does not participate in the water circulation of the cooling system), preventing the natural gas temperature from being too high, thereby controlling the natural gas temperature within a reasonable range. In addition, the opening of the second control valve can be controlled according to the intake air temperature, so that the intake air temperature is maintained within a reasonable range, reducing the risk of misfire or detonation.

[0077] like Figure 2 As shown, a control method provided in an embodiment of the present application is applicable to a cooling system of a natural gas engine, and includes the following steps.

[0078] S201: After the natural gas engine is started, the natural gas temperature, the intake air temperature and the engine outlet water temperature of the cooling system are monitored in real time.

[0079] S202: Based on the natural gas temperature, controlling the state of the first control valve to adjust the water path of the cooling system to increase the temperature of the natural gas in the vaporizer.

[0080] Optionally, based on the natural gas temperature, the state of the first control valve is controlled to adjust the water circuit of the cooling system to heat the natural gas in the vaporizer, and the implementation process includes: when the natural gas temperature is lower than a first calibrated temperature, the first control valve is controlled to be in an open state, triggering the water circuit of the vaporizer in the cooling system to participate in the water circulation of the cooling system, so that the cooling water of the cooling system heats the natural gas in the vaporizer; when the natural gas temperature is higher than a second calibrated temperature, the first control valve is controlled to be in a closed state, triggering the water circuit of the vaporizer to not participate in the water circulation of the cooling system; the first calibrated temperature is lower than the second calibrated temperature.

[0081] Optionally, when the natural gas temperature is greater than or equal to the first calibrated temperature and less than or equal to the second calibrated temperature, the temperature rise rate of the natural gas in the vaporizer is adjusted by controlling the opening of the first control valve in an open state; wherein the opening is directly proportional to the temperature rise rate.

[0082] S203: Based on the intake air temperature, the state of the second control valve is controlled to adjust the water path of the cooling system to cool the exhaust gas in the EGR cooler.

[0083] Optionally, based on the intake air temperature, the state of the second control valve is controlled to adjust the water circuit of the cooling system to cool the exhaust gas in the EGR cooler. The implementation process is as follows: when the intake air temperature is greater than or equal to a third calibration temperature, the second control valve is controlled to be in an open state, triggering the water circuit of the EGR cooler in the cooling system to participate in the water circulation of the cooling system, so that the cooling water of the cooling system cools the exhaust gas in the EGR cooler; when the intake air temperature is lower than the third calibration temperature, the second control valve is controlled to be in a closed state, triggering the water circuit of the EGR cooler to not participate in the water circulation of the cooling system.

[0084] S204: Based on the engine outlet water temperature, controlling the state of the third control valve to adjust the water path of the cooling system to cool down the cooling water of the cooling system.

[0085] Optionally, based on the engine water outlet temperature, the state of the third control valve is controlled to adjust the water circuit of the cooling system to cool the cooling water of the cooling system. The implementation process is as follows: when the engine water outlet temperature is greater than a fourth calibration temperature, the third control valve is controlled to be in an open state, thereby triggering the water circuit where the radiator is located in the cooling system to participate in the water circulation of the cooling system, so that the radiator cools the cooling water; when the engine water outlet temperature is less than or equal to the fourth calibration temperature, the third control valve is controlled to be in a closed state, thereby triggering the water circuit where the radiator is located to not participate in the water circulation of the cooling system.

[0086] In some examples, the first sensor is regarded as a natural gas temperature sensor, the second sensor is regarded as an intake air temperature sensor, the third sensor is regarded as an engine water temperature sensor, the first control valve is regarded as a carburetor water circuit control valve, the second control valve is regarded as an EGR cooler water circuit control valve, and the third control valve is regarded as a water outlet control valve. The control logic of the cooling system of the natural gas engine can also be referred to. Figure 7 As shown, it can be specifically summarized as step 1 to step 11.

[0087] Step 1: After the natural gas engine reaches the starting conditions, it is ignited and started.

[0088] Specifically, step 2 to step 5 can be regarded as a control process of the vaporizer.

[0089] Step 2: Based on the test signal of the natural gas temperature sensor, determine whether the natural gas temperature reaches T1 (i.e., the first calibration temperature). If the natural gas temperature is less than T1, it is determined that the natural gas is difficult to vaporize and burn in the engine cylinder, and go to step 3. If the natural gas temperature is greater than or equal to T1, it is determined that the natural gas can vaporize and burn in the engine cylinder, and go to step 4.

[0090] Step 3: When the natural gas temperature is low, the vaporizer water circuit control valve opens and the cooling water heats the natural gas.

[0091] Step 4: Determine whether the natural gas temperature is too high. If the natural gas temperature is less than T2 (i.e., the second calibration temperature), control the opening of the vaporizer water circuit control valve according to the natural gas temperature. If the natural gas temperature is greater than or equal to T2, proceed to step 5, in which the higher the natural gas temperature, the smaller the corresponding opening.

[0092] Step 5: The vaporizer water circuit control valve is closed, the cooling water stops heating the natural gas, and the process returns to step 2.

[0093] Specifically, step 6 to step 8 can be regarded as a control process of the EGR cooler.

[0094] Step 6: Determine whether the intake air temperature is too high based on the test signal of the intake air temperature sensor. If the intake air temperature is less than T3 (ie, the third calibration temperature), proceed to step 7. If the intake air temperature is greater than or equal to T3, proceed to step 8.

[0095] Step 7: The EGR cooler water circuit control valve is closed, and the water in the EGR cooler does not participate in the water circulation of the cooling system. The exhaust gas from EGR heats the low-temperature fresh air to increase the intake air temperature, and then returns to step 6.

[0096] Step 8: The EGR cooler water circuit control valve is opened, and the water in the EGR cooler participates in the water circulation of the cooling system, so that the intake air temperature is reduced, and return to step 6.

[0097] Step 9: Determine whether the engine water temperature is too high based on the test signal of the engine water temperature sensor. If the engine water temperature is less than T4 (ie, the fourth calibration temperature), proceed to step 10; if the engine water temperature is greater than or equal to T4, proceed to step 11.

[0098] Step 10: The water outlet control valve opens the water path to the water pump and closes the water path to the radiator, so that the water in the radiator does not participate in the water circulation of the cooling system, and returns to step 9.

[0099] Step 11: The water outlet control valve closes the water path to the water pump and opens the water path to the radiator, so that the water in the radiator circulates and dissipates heat, and then returns to step 6.

[0100] The process shown in S201-S204 above controls the corresponding water paths of the carburetor and the EGR cooler, so that the natural gas temperature and the intake air temperature are maintained within a reasonable range, which has a significant performance improvement in terms of improving the natural gas temperature control accuracy and optimizing the combustion in the engine cylinder.

[0101] The present application also provides a computer-readable storage medium, which includes a stored program, wherein the program executes the control method provided by the present application.

[0102] The present application also provides a vehicle, including: a processor, a memory and a bus. The processor and the memory are connected via the bus, the memory is used to store a program, and the processor is used to run the program, wherein the control method provided by the present application is executed when the program is run.

[0103] Although several specific implementation details are included in the above discussion, these should not be interpreted as limiting the scope of the present application. Certain features described in the context of a separate embodiment can also be implemented in a single embodiment in combination. On the contrary, the various features described in the context of a single embodiment can also be implemented in multiple embodiments individually or in any suitable sub-combination.

[0104] The above description is only a preferred embodiment of the present application and an explanation of the technical principles used. Those skilled in the art should understand that the scope of disclosure involved in the present application is not limited to the technical solution formed by a specific combination of the above technical features, but should also cover other technical solutions formed by any combination of the above technical features or their equivalent features without departing from the above disclosed concept. For example, the above features are replaced with the technical features with similar functions disclosed in this application (but not limited to) by each other to form a technical solution.

Claims

1. A cooling system for a natural gas engine, characterized in that: include: Water pump, components to be cooled, carburetor, EGR cooler, radiator, temperature monitoring module and water circuit control module; The water pump is used to provide cooling water to the water circuit of the cooling system; The temperature monitoring module includes a first sensor, a second sensor and a third sensor; the first sensor is deployed on the carburetor to monitor the natural gas temperature in the carburetor; the second sensor is deployed on the EGR cooler to monitor the intake air temperature of the EGR cooler; the third sensor is deployed on the water path where the component to be cooled is located to monitor the engine outlet water temperature; The water circuit control module includes a first control valve, a second control valve and a third control valve; the first control valve is deployed on the water circuit where the vaporizer is located, and is used to control the water circuit where the vaporizer is located to participate in the water circulation of the cooling system; the second control valve is deployed on the water circuit where the EGR cooler is located, and is used to control the water circuit where the EGR cooler is located to participate in the water circulation of the cooling system; the third control valve is deployed on the water circuit where the radiator is located, and is used to control the water circuit where the radiator is located to participate in the water circulation of the cooling system.

2. The cooling system according to claim 1, characterized in that: When the natural gas temperature is lower than the first calibration temperature, the first control valve is in an open state, and the water circuit where the vaporizer is located participates in the water circulation of the cooling system, so that the cooling water heats the natural gas in the vaporizer; when the natural gas temperature is higher than the second calibration temperature, the first control valve is in a closed state, and the water circuit where the vaporizer is located does not participate in the water circulation of the cooling system; the first calibration temperature is lower than the second calibration temperature.

3. The cooling system according to claim 1, characterized in that: When the intake air temperature is greater than or equal to the third calibration temperature, the second control valve is in an open state, and the water circuit where the EGR cooler is located participates in the water circulation of the cooling system, so that the cooling water cools the exhaust gas in the EGR cooler; when the intake air temperature is lower than the third calibration temperature, the second control valve is in a closed state, and the water circuit where the EGR cooler is located does not participate in the water circulation of the cooling system.

4. The cooling system according to claim 1, characterized in that: When the engine outlet water temperature is greater than the fourth calibrated temperature, the third control valve is controlled to be in an open state, and the water circuit where the radiator is located participates in the water circulation of the cooling system, so that the radiator cools the cooling water; when the engine outlet water temperature is less than or equal to the fourth calibrated temperature, the third control valve is controlled to be in a closed state, and the water circuit where the radiator is located does not participate in the water circulation of the cooling system.

5. A control method, characterized in that: Applied to the cooling system according to any one of claims 1 to 4 above, the method comprises: When the natural gas engine is started, the natural gas temperature, the intake air temperature and the engine outlet water temperature of the cooling system are monitored in real time; Based on the natural gas temperature, controlling the state of the first control valve to adjust the water path of the cooling system to heat the natural gas in the vaporizer; Based on the intake air temperature, controlling the state of the second control valve to adjust the water path of the cooling system to cool the exhaust gas in the EGR cooler; Based on the engine outlet water temperature, the state of the third control valve is controlled to adjust the water path of the cooling system to cool the cooling water of the cooling system.

6. The control method according to claim 5, characterized in that: Based on the natural gas temperature, controlling the state of the first control valve to adjust the water path of the cooling system to heat the natural gas in the vaporizer, including: When the temperature of the natural gas is lower than the first calibration temperature, the first control valve is controlled to be in an open state, triggering the water path where the vaporizer in the cooling system is located to participate in the water circulation of the cooling system, so that the cooling water of the cooling system heats the natural gas in the vaporizer; When the natural gas temperature is greater than the second calibration temperature, the first control valve is controlled to be in a closed state, triggering the water circuit where the vaporizer is located not to participate in the water circulation of the cooling system; the first calibration temperature is lower than the second calibration temperature.

7. The control method according to claim 5, characterized in that: Based on the intake air temperature, controlling the state of the second control valve to adjust the water path of the cooling system to cool the exhaust gas in the EGR cooler includes: When the intake air temperature is greater than or equal to the third calibration temperature, the second control valve is controlled to be in an open state, triggering the water path where the EGR cooler in the cooling system is located to participate in the water circulation of the cooling system, so that the cooling water of the cooling system cools down the exhaust gas in the EGR cooler; When the intake air temperature is lower than the third calibrated temperature, the second control valve is controlled to be in a closed state, so that the water path where the EGR cooler is located does not participate in the water circulation of the cooling system.

8. The control method according to claim 5, characterized in that: Based on the engine outlet water temperature, controlling the state of the third control valve to adjust the water path of the cooling system to cool the cooling water of the cooling system includes: When the engine outlet water temperature is greater than a fourth calibration temperature, the third control valve is controlled to be in an open state, triggering the water path where the radiator in the cooling system is located to participate in the water circulation of the cooling system, so that the radiator cools the cooling water; When the engine outlet water temperature is less than or equal to the fourth calibrated temperature, the third control valve is controlled to be in a closed state, which triggers the water path where the radiator is located to not participate in the water circulation of the cooling system.

9. The control method according to claim 6, characterized in that: The control method further comprises: When the natural gas temperature is greater than or equal to the first calibration temperature and less than or equal to the second calibration temperature, the opening of the first control valve in the open state is controlled to adjust the heating rate of the natural gas in the vaporizer; wherein the opening is proportional to the heating rate.

10. A vehicle, characterized in that: include: A processor, a memory and a bus, wherein the processor and the memory are connected via the bus, the memory is used to store programs, and the processor is used to run programs, wherein the program executes the control method described in any one of claims 5 to 9 when it is run.

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