Air inlet temperature control module, method and device of methanol fuel engine

Abstract

The invention discloses an air inlet temperature control module, method and device of a methanol fuel engine. A liquid path switching valve is arranged on the downstream of an engine high-temperature liquid path and an engine low-temperature liquid path and used for guiding engine high-temperature liquid or engine low-temperature liquid into a waste gas waste heat exchanger; the waste gas conduction valve is arranged at the downstream of the waste gas pipeline and is used for introducing the high-temperature waste gas into the waste gas waste heat exchanger when the waste gas conduction valve is controlled to be conducted; the liquid temperature sensor, the flow control valve and the valve position sensor are sequentially arranged on the downstream portion of the waste gas waste heat exchanger. The valve position sensor is located on a liquid path on the upstream portion of the intercooler. And the air inlet temperature sensor is arranged in the air inlet pipeline at the downstream of the intercooler. All the units are matched with one another, the air inlet temperature after intercooling can be strictly controlled, and then the stability during methanol gasification combustion is improved.

Description

Technical Field

[0001] This invention relates to the field of methanol fuel engine technology, and in particular to an intake air temperature control module, method and device for a methanol fuel engine. Background Technology

[0002] Methanol, as a clean fuel, has broad application prospects in the engine field. However, the combustion process of methanol involves the vaporization of liquid into gas, which is then ignited in the cylinder by diesel fuel or a spark plug. Therefore, the requirements for the intake air temperature after intercooling are relatively strict, especially under low operating conditions where power is low and it is difficult to raise the intercooled temperature to a suitable value. Precise intake air temperature control is one of the key technologies to ensure the efficient and stable operation of methanol engines.

[0003] Existing technologies for controlling intake air temperature in methanol engines monitor the status using temperature sensors located in the intake manifold and exhaust temperature and knock sensors in each cylinder. The control core relies on flow valves in the intercooler circuit and electromagnetic fans for auxiliary cooling. The control unit adjusts the coolant flow and fan start / stop based on sensor signals, thereby regulating the air temperature entering the engine manifold.

[0004] This scheme has the following main drawbacks: First, it relies on additional temperature control devices such as fans, which increases the system cost and complexity. Second, in the single-sided manifold intake layout, the path length from the temperature control point to each cylinder varies, resulting in uneven actual intake temperatures in each cylinder, which seriously affects the consistency and efficiency of methanol combustion in multiple cylinders. Summary of the Invention

[0005] This invention provides an intake air temperature control module, method, and device for a methanol fuel engine, which can strictly control the intake air temperature after intercooling, thereby improving the stability of methanol gasification and combustion.

[0006] In a first aspect, embodiments of the present invention provide an intake air temperature control module for a methanol fuel engine, comprising: an intake air temperature control device for a methanol fuel engine, a liquid temperature control unit, a flow control unit, and an intake air temperature sensor. The intake air temperature control device of the methanol fuel engine is electrically connected to the liquid temperature control unit, the flow control unit, and the intake air temperature sensor. The liquid temperature control unit includes a liquid circuit switching valve, an exhaust gas conduction valve, and an exhaust gas waste heat exchanger; the flow control unit includes a liquid temperature sensor, a flow control valve, and a valve position sensor. The fluid switching valve is located downstream of the engine high-temperature fluid circuit and the engine low-temperature fluid circuit, and is used to introduce the engine high-temperature fluid or engine low-temperature fluid into the exhaust gas waste heat exchanger; the exhaust gas conduction valve is located downstream of the exhaust gas pipeline, and is used to introduce high-temperature exhaust gas into the exhaust gas waste heat exchanger when the exhaust gas conduction valve is opened. The liquid temperature sensor, the flow control valve, and the valve position sensor are sequentially arranged downstream of the waste heat exchanger, with the valve position sensor located in the liquid path upstream of the intercooler; the intake air temperature sensor is arranged in the intake pipe downstream of the intercooler.

[0007] Secondly, embodiments of the present invention also provide an intake air temperature control method for a methanol fuel engine, implemented using the intake air temperature control module for a methanol fuel engine described in the first aspect, comprising: The operating conditions of the methanol fuel engine and the actual intake air temperature after intercooling collected by the intake air temperature sensor are obtained. When the methanol fuel engine is detected to be in a low-load condition and the intake air temperature collected by the intake air temperature sensor is lower than the preset low-load condition intake air temperature, the liquid temperature collected by the liquid temperature sensor is obtained. When the fluid temperature is detected to be within the temperature range of the engine's low-temperature fluid, the fluid circuit switching valve is controlled to switch to the engine's high-temperature fluid circuit, and the engine's high-temperature fluid is introduced into the exhaust gas waste heat exchanger. The difference between the preset low-load intake temperature and the actual intercooled intake temperature is used as the PID input. The required opening degree of the flow control valve is determined through PID calculation, and the flow control valve is controlled to open according to the required opening degree.

[0008] Optionally, after obtaining the operating conditions of the methanol fuel engine and the intake air temperature collected by the intake air temperature sensor, the method further includes: When the methanol fuel engine is detected to be under high load, and the intake air temperature collected by the intake air temperature sensor is higher than the preset high load intake air temperature, the liquid circuit switching valve is controlled to switch to the engine cryogenic liquid circuit, and the engine cryogenic liquid is introduced into the exhaust gas waste heat exchanger. The difference between the preset high-load intake temperature and the actual intercooled intake temperature is used as the PID input. The required opening degree of the flow control valve is determined through PID calculation, and the flow control valve is controlled to open according to the required opening degree.

[0009] Optionally, the difference between the preset low-load intake temperature and the actual intercooled intake temperature is used as the PID input. The required opening degree of the flow control valve is determined through PID calculation. After controlling the flow control valve to open according to the required opening degree, the method further includes: When the engine is detected to be in a knocking condition and the intake air temperature collected by the intake air temperature sensor is higher than the preset knocking condition intake air temperature, the liquid circuit switching valve is controlled to switch to the engine cryogenic liquid circuit.

[0010] Optionally, the difference between the preset low-load intake temperature and the actual intercooled intake temperature is used as the PID input. The required opening degree of the flow control valve is determined through PID calculation. After controlling the flow control valve to open according to the required opening degree, the method further includes: The exhaust gas conduction valve is opened to introduce high-temperature exhaust gas into the exhaust gas waste heat exchanger.

[0011] Optionally, after controlling the opening of the exhaust gas conduction valve to introduce high-temperature exhaust gas into the exhaust gas waste heat exchanger, the method further includes: When the engine is detected to be in a knocking condition, and the actual opening of the flow control valve is less than the preset opening and is maintained for a preset time, and the intake air temperature collected by the intake air temperature sensor is detected to be higher than the preset knocking condition intake air temperature, the liquid circuit switching valve is controlled to switch to the engine cryogenic liquid circuit, and the exhaust gas conduction valve is controlled to close.

[0012] Optionally, before obtaining the operating conditions of the methanol fuel engine and the actual intercooled intake air temperature collected by the intake air temperature sensor, the method further includes: The optimal intake temperature for methanol combustion stability under various operating conditions of the methanol fuel engine is obtained as the preset intake temperature; the preset intake temperature includes: preset low load condition intake temperature, preset high load condition intake temperature and preset knock condition intake temperature. Establish the intake air temperature curve between operating conditions and preset operating conditions.

[0013] Thirdly, embodiments of the present invention also provide an intake air temperature control device for a methanol fuel engine, used to execute the intake air temperature control method for a methanol fuel engine described in the second aspect, comprising: The data acquisition module is used to acquire the operating conditions of the methanol fuel engine and the intake air temperature collected by the intake air temperature sensor; it is also used to acquire the liquid temperature collected by the liquid temperature sensor when it is detected that the methanol fuel engine is in a low-load condition and the intake air temperature collected by the intake air temperature sensor is lower than the preset low-load condition intake air temperature. The liquid circuit switching valve control module is used to control the liquid circuit switching valve to switch to the engine high-temperature liquid circuit when the data acquisition module detects that the liquid temperature is within the temperature range of the engine low-temperature liquid, so as to introduce the engine high-temperature liquid into the exhaust gas waste heat exchanger. The flow control valve control module is used to take the difference between the preset low-load intake temperature and the actual intercooled intake temperature as the PID input, and through PID calculation, determine the required opening degree of the flow control valve, and control the flow control valve to open according to the required opening degree.

[0014] Optionally, it also includes: an exhaust gas conduction valve control module, used to control the opening of the exhaust gas conduction valve to introduce high-temperature exhaust gas into the exhaust gas waste heat exchanger.

[0015] Optionally, it also includes: a preset operating condition intake air temperature determination module, used to obtain the intake air temperature with the best methanol combustion stability under various operating conditions of the methanol fuel engine as the preset operating condition intake air temperature; the preset operating condition intake air temperature includes: preset low load condition intake air temperature, preset high load condition intake air temperature and preset knock condition intake air temperature. The module for establishing the intake air temperature curve between operating conditions and preset operating conditions is used to establish the intake air temperature curve between operating conditions and preset operating conditions.

[0016] This invention provides an intake air temperature control module, method, and apparatus for a methanol fuel engine. A fluid switching valve is located downstream of the engine's high-temperature fluid circuit and low-temperature fluid circuit, used to introduce either the high-temperature or low-temperature fluid into the exhaust gas waste heat exchanger. An exhaust gas conduction valve is located downstream of the exhaust gas pipeline, used to introduce high-temperature exhaust gas into the waste heat exchanger when the exhaust gas conduction valve is open. A fluid temperature sensor, a flow control valve, and a valve position sensor are sequentially located downstream of the waste heat exchanger, with the valve position sensor located in the fluid circuit upstream of the intercooler. An intake air temperature sensor is located in the intake pipeline downstream of the intercooler. When the engine is under low load and the actual intake air temperature after intercooling is low, the fluid switching valve is controlled to switch to the engine's high-temperature fluid circuit, introducing the high-temperature fluid into the waste heat exchanger for heating. Alternatively, the exhaust gas conduction valve can be opened to introduce high-temperature exhaust gas into the waste heat exchanger, thereby increasing the intake air temperature after intercooling. When the engine is under high load or knocking conditions, the liquid temperature control unit and flow control unit can work together to better control the intake air temperature after intercooling. This allows for strict control of the intake air temperature after intercooling at a low cost, thereby improving the stability of methanol vaporization combustion.

[0017] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of the present invention, nor is it intended to limit the scope of the invention. Other features of the invention will become readily apparent from the following description. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1This is a schematic diagram of the intake air temperature control module of a methanol fuel engine provided in an embodiment of the present invention; Figure 2 This is a flowchart of an intake air temperature control method for a methanol fuel engine provided in an embodiment of the present invention; Figure 3 This is a flowchart of another method for controlling the intake air temperature of a methanol fuel engine provided in an embodiment of the present invention; Figure 4 This is a schematic diagram of the intake air temperature control device for a methanol fuel engine provided in an embodiment of the present invention; Figure 5 This is a schematic diagram of the intake air temperature control device for another methanol fuel engine provided in an embodiment of the present invention. Detailed Implementation

[0020] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0021] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0022] Figure 1 This is a schematic diagram of the intake air temperature control module of a methanol fuel engine provided in an embodiment of the present invention. (Refer to...) Figure 1The module includes: an intake air temperature control device 110 for a methanol fuel engine, a liquid temperature control unit 120, a flow control unit 130, and an intake air temperature sensor 140; the intake air temperature control device 110 is electrically connected to the liquid temperature control unit 120, the flow control unit 130, and the intake air temperature sensor 140; the liquid temperature control unit 120 includes a liquid circuit switching valve 121, an exhaust gas conduction valve 122, and an exhaust gas waste heat exchanger 123; the flow control unit 130 includes a liquid temperature sensor 131, a flow control valve 132, and a valve position sensor 133; the liquid circuit switching valve 120... 21 is located downstream of the engine high-temperature liquid passage A and the engine low-temperature liquid passage B, and is used to introduce the engine high-temperature liquid or engine low-temperature liquid into the exhaust gas waste heat exchanger 123; the exhaust gas conduction valve 122 is located downstream of the exhaust gas pipeline, and is used to introduce high-temperature exhaust gas into the exhaust gas waste heat exchanger 123 when the exhaust gas conduction valve 122 is opened; the liquid temperature sensor 131, the flow control valve 132, and the valve position sensor 133 are sequentially located downstream of the exhaust gas waste heat exchanger 123, and the valve position sensor 133 is located in the liquid passage upstream of the intercooler; the intake air temperature sensor 140 is located in the intake pipe downstream of the intercooler.

[0023] Specifically, the intake air temperature control device 110 of the methanol fuel engine can be an Electronic Control Unit (ECU). The intake air temperature control device 110 is electrically connected to the liquid temperature control unit 120, the flow control unit 130, and the intake air temperature sensor 140. Therefore, it can control the liquid temperature control unit 120, the flow control unit 130, and the intake air temperature sensor 140 through a pre-set control algorithm, or acquire information collected by the flow control unit 130 and the intake air temperature sensor 140. The liquid circuit switching valve 121 controls the source of the liquid entering the intercooler, thereby controlling the liquid temperature. The flow control valve 132 controls the flow rate of the liquid entering the intercooler. The intake air temperature control device 110 of the methanol fuel engine can determine the engine's operating conditions by detecting the engine speed and intake air volume.

[0024] It should be noted that the high-temperature fluid in the engine can be the high-temperature coolant flowing through the engine cylinder head, while the low-temperature fluid can be the coolant flowing through other parts of the engine at a lower temperature. The intake pipe downstream of the intercooler can be the engine's main intake manifold or the intake manifold of a single cylinder.

[0025] Among them, liquid temperature sensor 131 is used to collect liquid temperature, valve position sensor 133 is used to collect the actual opening degree of flow control valve 132, and intake air temperature sensor 140 is used to collect the actual intake air temperature after intercooling.

[0026] The intake air temperature control module for the methanol fuel engine provided in this embodiment of the invention can control the liquid circuit switching valve 121 to switch to the engine high-temperature liquid circuit A when the engine is under low load and the actual intake air temperature after intercooling is low. This introduces the high-temperature liquid from the engine into the exhaust gas waste heat exchanger 123 for heating. It can also control the exhaust gas conduction valve 122 to open, introducing high-temperature exhaust gas into the exhaust gas waste heat exchanger 123, thereby increasing the intake air temperature after intercooling. When the engine is under high load or knocking conditions, the liquid temperature control unit 120 and the flow control unit 130 can work together to better control the intake air temperature after intercooling. This allows for strict control of the intake air temperature after intercooling at a low cost, thereby improving the stability of methanol vaporization and combustion.

[0027] Figure 2 This is a flowchart of an intake air temperature control method for a methanol fuel engine provided in an embodiment of the present invention. This embodiment is applicable to controlling the intake air temperature of an engine. The method can be executed by an intake air temperature control device 110 of the methanol fuel engine, implemented using an intake air temperature control module for the methanol fuel engine. The intake air temperature control device 110 can be implemented in hardware and / or software. (Reference) Figure 2 The method includes the following steps: S210: Obtain the operating conditions of the methanol fuel engine and the actual intake air temperature after intercooling collected by the intake air temperature sensor 140.

[0028] Specifically, the operating conditions of the methanol fuel engine are determined by obtaining the engine speed and intake air volume.

[0029] S220. When it is detected that the methanol fuel engine is under low load and the intake air temperature collected by the intake air temperature sensor 140 is lower than the preset low load intake air temperature, the liquid temperature collected by the liquid temperature sensor 131 is obtained.

[0030] S230. When the fluid temperature is detected to be within the temperature range of the engine's low-temperature fluid, the control fluid switching valve 121 is switched to the engine's high-temperature fluid circuit A, and the engine's high-temperature fluid is introduced into the exhaust gas waste heat exchanger 123.

[0031] Understandably, when the methanol fuel engine is under low load and the intake air temperature collected by the intake air temperature sensor 140 is lower than the preset low load intake air temperature, the system switches to the engine high-temperature fluid circuit A via the control fluid circuit switching valve 121. This introduces the engine's high-temperature fluid into the exhaust gas waste heat exchanger 123, increasing the temperature of the fluid entering the intercooler and thus raising the intake air temperature after intercooling. Specifically, the temperature range of the engine's low-temperature fluid can be determined through calibration.

[0032] S240: The difference between the preset low-load intake temperature and the actual intercooled intake temperature is used as the PID input. The required opening degree of the flow control valve 132 is determined through PID calculation, and the flow control valve 132 is controlled to open according to the required opening degree.

[0033] Specifically, the Proportional-Integral-Derivative (PID) controller is a linear control algorithm based on error feedback, widely used in process control and motion control systems. The difference between the required opening degree and the actual opening degree signal of the flow control valve 132 collected by the valve position sensor 133 can be used as the PID input. After PID calculation, the flow control valve 132 is controlled, thereby controlling the actual intercooled intake air temperature.

[0034] This embodiment can strictly control the intake temperature after intercooling under low load conditions at a low cost, thereby improving the stability of methanol gasification and combustion.

[0035] Figure 3 This is a flowchart of another intake air temperature control method for a methanol fuel engine provided by an embodiment of the present invention. Optionally, based on the above embodiments, refer to... Figure 3 After step S210, the method further includes: S310 When it is detected that the methanol fuel engine is under high load and the intake air temperature collected by the intake air temperature sensor 140 is higher than the preset high load intake air temperature, the control fluid switching valve 121 switches to the engine cryogenic fluid circuit B and introduces the engine cryogenic fluid into the exhaust gas waste heat exchanger 123.

[0036] Specifically, the preset intake temperature under high load conditions can be determined through calibration.

[0037] S320: The difference between the preset high-load intake temperature and the actual intercooled intake temperature is used as the PID input. Through PID calculation, the required opening degree of the flow control valve 132 is determined, and the flow control valve 132 is controlled to open according to the required opening degree.

[0038] This embodiment can strictly control the intake temperature after intercooling under high load conditions at a low cost, thereby improving the stability of methanol gasification and combustion.

[0039] Optionally, based on the above embodiments, continue to refer to... Figure 3 After step S240, the method further includes: S330 When the engine is detected to be in a knocking condition and the intake air temperature collected by the intake air temperature sensor 140 is higher than the preset knocking condition intake air temperature, the control fluid switching valve 121 switches to the engine cryogenic fluid circuit B.

[0040] This embodiment can switch the control fluid switching valve 121 to the engine cryogenic fluid circuit B when the engine is in a knocking condition, at low cost. This can quickly reduce the intake air temperature after intercooling, thereby suppressing knocking and improving the stability of methanol vaporization combustion.

[0041] Optionally, based on the above embodiments, continue to refer to... Figure 3 After step S240, the method further includes: S340, control the opening of the exhaust gas conduction valve 122 to introduce high-temperature exhaust gas into the exhaust gas waste heat exchanger 123.

[0042] In this embodiment, by controlling the opening of the exhaust gas conduction valve 122, high-temperature exhaust gas is introduced into the exhaust gas waste heat exchanger 123, which can further increase the temperature of the engine's high-temperature liquid and accelerate the rise of the intake air temperature after intercooling. This can quickly improve the stability of methanol vaporization combustion at low cost.

[0043] Optionally, based on the above embodiments, continue to refer to... Figure 3 After step S340, the following steps are also included: S350, when the engine is detected to be in a knocking condition and the actual opening of the flow control valve 132 is less than the preset opening and is maintained for a preset time, when the intake air temperature collected by the intake air temperature sensor 140 is detected to be higher than the preset knocking condition intake air temperature, the control fluid switching valve 121 is switched to the engine cryogenic fluid circuit B, and the exhaust gas conduction valve 122 is closed.

[0044] Specifically, the preset opening and preset time can be set freely, and the preset opening can be set to close to 0.

[0045] In this embodiment, when the engine is in a knocking condition, the actual opening of the flow control valve 132 under the knocking condition is first adjusted to be smaller to suppress knocking. After a period of time, when the intake air temperature collected by the intake air temperature sensor 140 is higher than the preset intake air temperature under the knocking condition, the control fluid switching valve 121 is switched to the engine low-temperature fluid circuit B, and the exhaust gas conduction valve 122 is closed at the same time, which can further suppress knocking and improve the stability of methanol vaporization combustion at low cost.

[0046] Optionally, based on the above embodiments, before obtaining the operating conditions of the methanol fuel engine and the intake air temperature collected by the intake air temperature sensor 140, the method further includes: obtaining the intake air temperature with the best methanol combustion stability under each operating condition of the methanol fuel engine as the preset operating condition intake air temperature; the preset operating condition intake air temperature includes: preset low load operating condition intake air temperature, preset high load operating condition intake air temperature and preset knock operating condition intake air temperature; and establishing an operating condition-preset operating condition intake air temperature curve.

[0047] The operating condition-preset operating condition intake temperature curve obtained in this embodiment can provide a basis for adjusting the actual intake temperature after intercooling, thereby improving the stability of methanol gasification combustion at low cost.

[0048] Figure 4 This is a schematic diagram of the intake air temperature control device for a methanol fuel engine provided in an embodiment of the present invention, used to execute the intake air temperature control method for the methanol fuel engine provided in the above embodiment. (Refer to...) Figure 4 The device includes: a data acquisition module 410, used to acquire the operating conditions of the methanol fuel engine and the intake air temperature collected by the intake air temperature sensor 140; and also used to acquire the liquid temperature collected by the liquid temperature sensor 131 when the methanol fuel engine is detected to be under low load and the intake air temperature collected by the intake air temperature sensor 140 is lower than the preset low load operating condition intake air temperature; a liquid circuit switching valve 121 control module 420, used to control the liquid circuit switching valve 121 to switch to the engine high temperature liquid circuit A when the data acquisition module detects that the liquid temperature is within the temperature range of the engine low temperature liquid, and introduce the engine high temperature liquid into the exhaust gas waste heat exchanger 123; and a flow control valve 132 control module 430, used to take the difference between the preset low load operating condition intake air temperature and the actual intercooled intake air temperature as the PID input, and determine the required opening degree of the flow control valve 132 through PID calculation, and control the flow control valve 132 to open according to the required opening degree.

[0049] Figure 5 This is a schematic diagram of the intake air temperature control device for another methanol fuel engine provided in an embodiment of the present invention. Optionally, based on the above embodiment, refer to... Figure 5 The device also includes a waste gas conduction valve 122 control module 510, which controls the opening of the waste gas conduction valve 122 to introduce high-temperature waste gas into the waste gas waste heat exchanger 123.

[0050] Optionally, based on the above embodiments, continue to refer to... Figure 5 The device also includes: a preset operating condition intake air temperature determination module 520, used to obtain the intake air temperature with the best methanol combustion stability under various operating conditions of the methanol fuel engine as the preset operating condition intake air temperature; the preset operating condition intake air temperature includes: preset low load condition intake air temperature, preset high load condition intake air temperature and preset knock condition intake air temperature; and an operating condition-preset operating condition intake air temperature curve establishment module 530, used to establish the operating condition-preset operating condition intake air temperature curve.

[0051] The intake air temperature control device 110 for a methanol fuel engine provided in this embodiment of the invention can execute the intake air temperature control method for a methanol fuel engine provided in any embodiment of the invention. It has the corresponding functional modules and beneficial effects of the execution method. For contents not described in detail in this embodiment, please refer to the intake air temperature control method for a methanol fuel engine provided in the above embodiments.

[0052] It should be understood that the various forms of processes shown above can be used, with steps reordered, added, or deleted. For example, the steps described in this invention can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution of this invention can be achieved, and this is not limited herein.

[0053] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. 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 substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. An intake air temperature control module for a methanol fuel engine, characterized in that, include: Intake air temperature control device, liquid temperature control unit, flow control unit, and intake air temperature sensor for methanol fuel engine; The intake air temperature control device of the methanol fuel engine is electrically connected to the liquid temperature control unit, the flow control unit, and the intake air temperature sensor. The liquid temperature control unit includes a liquid circuit switching valve, an exhaust gas conduction valve, and an exhaust gas waste heat exchanger; the flow control unit includes a liquid temperature sensor, a flow control valve, and a valve position sensor. The fluid switching valve is located downstream of the engine high-temperature fluid circuit and the engine low-temperature fluid circuit, and is used to introduce the engine high-temperature fluid or engine low-temperature fluid into the exhaust gas waste heat exchanger; the exhaust gas conduction valve is located downstream of the exhaust gas pipeline, and is used to introduce high-temperature exhaust gas into the exhaust gas waste heat exchanger when the exhaust gas conduction valve is opened. The liquid temperature sensor, the flow control valve, and the valve position sensor are sequentially arranged downstream of the waste heat exchanger, with the valve position sensor located in the liquid path upstream of the intercooler; the intake air temperature sensor is arranged in the intake pipe downstream of the intercooler.

2. A method for controlling the intake air temperature of a methanol fuel engine, implemented using the intake air temperature control module for a methanol fuel engine as described in claim 1, characterized in that, include: The operating conditions of the methanol fuel engine and the actual intake air temperature after intercooling collected by the intake air temperature sensor are obtained. When the methanol fuel engine is detected to be in a low-load condition and the intake air temperature collected by the intake air temperature sensor is lower than the preset low-load condition intake air temperature, the liquid temperature collected by the liquid temperature sensor is obtained. When the fluid temperature is detected to be within the temperature range of the engine's low-temperature fluid, the fluid circuit switching valve is controlled to switch to the engine's high-temperature fluid circuit, and the engine's high-temperature fluid is introduced into the exhaust gas waste heat exchanger. The difference between the preset low-load intake temperature and the actual intercooled intake temperature is used as the PID input. The required opening degree of the flow control valve is determined through PID calculation, and the flow control valve is controlled to open according to the required opening degree.

3. The intake air temperature control method for a methanol fuel engine according to claim 2, characterized in that, After obtaining the operating conditions of the methanol fuel engine and the intake air temperature collected by the intake air temperature sensor, the method further includes: When the methanol fuel engine is detected to be under high load, and the intake air temperature collected by the intake air temperature sensor is higher than the preset high load intake air temperature, the liquid circuit switching valve is controlled to switch to the engine cryogenic liquid circuit, and the engine cryogenic liquid is introduced into the exhaust gas waste heat exchanger. The difference between the preset high-load intake temperature and the actual intercooled intake temperature is used as the PID input. The required opening degree of the flow control valve is determined through PID calculation, and the flow control valve is controlled to open according to the required opening degree.

4. The intake air temperature control method for a methanol fuel engine according to claim 2, characterized in that, The difference between the preset low-load intake air temperature and the actual intercooled intake air temperature is used as the PID input. Through PID calculation, the required opening degree of the flow control valve is determined. After controlling the flow control valve to open according to the required opening degree, the process further includes: When the engine is detected to be in a knocking condition and the intake air temperature collected by the intake air temperature sensor is higher than the preset knocking condition intake air temperature, the liquid circuit switching valve is controlled to switch to the engine cryogenic liquid circuit.

5. The intake air temperature control method for a methanol fuel engine according to claim 2, characterized in that, The difference between the preset low-load intake air temperature and the actual intercooled intake air temperature is used as the PID input. Through PID calculation, the required opening degree of the flow control valve is determined. After controlling the flow control valve to open according to the required opening degree, the process further includes: The exhaust gas conduction valve is opened to introduce high-temperature exhaust gas into the exhaust gas waste heat exchanger.

6. The intake air temperature control method for a methanol fuel engine according to claim 5, characterized in that, After controlling the opening of the exhaust gas conduction valve to introduce high-temperature exhaust gas into the exhaust gas waste heat exchanger, the method further includes: When the engine is detected to be in a knocking condition, and the actual opening of the flow control valve is less than the preset opening and is maintained for a preset time, and the intake air temperature collected by the intake air temperature sensor is detected to be higher than the preset knocking condition intake air temperature, the liquid circuit switching valve is controlled to switch to the engine cryogenic liquid circuit, and the exhaust gas conduction valve is controlled to close.

7. The intake air temperature control method for a methanol fuel engine according to claim 2, characterized in that, Before obtaining the operating conditions of the methanol fuel engine and the actual intercooled intake air temperature collected by the intake air temperature sensor, the following steps are also included: The optimal intake temperature for methanol combustion stability under various operating conditions of the methanol fuel engine is obtained as the preset intake temperature; the preset intake temperature includes: preset low load condition intake temperature, preset high load condition intake temperature and preset knock condition intake temperature. Establish the intake air temperature curve between operating conditions and preset operating conditions.

8. An intake air temperature control device for a methanol fuel engine, used to execute the intake air temperature control method for a methanol fuel engine according to any one of claims 2-7, characterized in that, include: The data acquisition module is used to acquire the operating conditions of the methanol fuel engine and the intake air temperature collected by the intake air temperature sensor. It is also used to acquire the liquid temperature collected by the liquid temperature sensor when the methanol fuel engine is detected to be in a low-load condition and the intake air temperature collected by the intake air temperature sensor is lower than the preset low-load condition intake air temperature. The liquid circuit switching valve control module is used to control the liquid circuit switching valve to switch to the engine high-temperature liquid circuit when the data acquisition module detects that the liquid temperature is within the temperature range of the engine low-temperature liquid, so as to introduce the engine high-temperature liquid into the exhaust gas waste heat exchanger. The flow control valve control module is used to take the difference between the preset low-load intake temperature and the actual intercooled intake temperature as the PID input, and through PID calculation, determine the required opening degree of the flow control valve, and control the flow control valve to open according to the required opening degree.

9. The intake air temperature control device for a methanol fuel engine according to claim 8, characterized in that, Also includes: The exhaust gas conduction valve control module is used to control the opening of the exhaust gas conduction valve to introduce high-temperature exhaust gas into the exhaust gas waste heat exchanger.

10. The intake air temperature control device for a methanol fuel engine according to claim 8, characterized in that, Also includes: The preset operating condition intake air temperature determination module is used to obtain the intake air temperature with the best methanol combustion stability under various operating conditions of the methanol fuel engine as the preset operating condition intake air temperature. The preset operating condition intake temperature includes: preset low load condition intake temperature, preset high load condition intake temperature, and preset knock condition intake temperature; The module for establishing the intake air temperature curve between operating conditions and preset operating conditions is used to establish the intake air temperature curve between operating conditions and preset operating conditions.

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