Vehicle-mounted methanol-to-hydrogen system and method
By monitoring the temperature and pressure in the on-board methanol hydrogen production system in real time, adjusting the methanol injection flow rate and reactor temperature, the problems of unstable methanol injection and insufficient temperature regulation are solved, the efficiency of methanol cracking and hydrogen production is improved, the cost is reduced and the cost is improved. Convenience.
Patent Information
- Application Number
- CN202411383866.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-30
- Publication Date
- 2024-12-20
AI Technical Summary
The existing on-board methanol hydrogen generators have difficulty in cold start, unstable methanol injection flow rate and insufficient temperature adjustment, resulting in low efficiency of methanol cracking and hydrogen production, which increases the time and economic costs of users.
A vehicle-mounted methanol hydrogen production system is designed, including a methanol supply device, a methanol cracking reactor, a flow valve and a control unit. By monitoring the temperature and pressure in real time, the methanol injection flow rate and reactor temperature are adjusted to ensure the stability and uniformity of methanol injection. and improve the efficiency of methanol cleavage reaction.
The stability and uniformity of methanol injection are achieved, the efficiency of methanol cracking is improved, the cost of methanol is reduced, and the convenience and economy of the vehicle are improved.
Smart Images
Figure CN119163533A_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the field of methanol hydrogen production, and in particular to a vehicle-mounted methanol hydrogen production system and method. Background Art
[0002] With the urgent global demand for clean energy and the continuous development of hydrogen energy technology, methanol, as a hydrogen source with broad prospects, has become a hot research topic in hydrogen production technology. Methanol hydrogen production technology can not only achieve large-scale production of hydrogen, but also has a wide range of raw materials, is renewable, and is environmentally friendly.
[0003] In the automotive field, methanol hydrogen generators have potential application value. Existing methanol engines usually use fossil fuels such as gasoline, diesel or natural gas as ignition fuel to solve the problem of difficult cold start of methanol engines. This method requires the vehicle to be filled with two fuels (methanol and others) at the same time, and to be equipped with two sets of fuel supply systems, fuel storage systems, etc., which increases the vehicle's own weight and cost, and the control process is more complicated. For large-displacement engines, each cold start process will consume a large amount of ignition fuel, causing users to need to refill frequently, greatly reducing the convenience of vehicle use and bringing instability to users.
[0004] The vehicle-mounted methanol hydrogen generator can not only solve the cold start problem of the methanol engine, but also reduce the design difficulty of the methanol engine. However, due to the high requirements of the vehicle-mounted environment for hydrogen production equipment, such as volume, weight, reaction efficiency, etc., it is difficult for traditional fixed methanol hydrogen production equipment to meet the requirements of the vehicle-mounted environment. In addition, the existing vehicle-mounted methanol hydrogen generator is converted from the fixed methanol hydrogen production equipment. The methanol in the methanol cracking reactor enters in the form of flooding or injection. There is no fine control of the methanol injection flow rate. The unstable flow rate during the methanol injection process will cause uneven injection. There is no temperature adjustment, and the efficiency of methanol cracking hydrogen production cannot be maximized, which reduces the economic efficiency of methanol use and increases the user's time and economic costs. Summary of the invention
[0005] The purpose of this application is to provide a vehicle-mounted methanol hydrogen production system and method, which can achieve the stability and uniformity of methanol injection and improve the efficiency of methanol cracking to produce hydrogen.
[0006] To achieve the above objectives, this application provides the following solutions:
[0007] In a first aspect, the present application provides a vehicle-mounted methanol hydrogen production system, comprising: a methanol supply device, a methanol cracking reactor, a first flow valve, a second flow valve, a third flow valve, a control unit, a temperature sensing device and a pressure sensing device; the first flow valve is arranged on a main supply pipeline connected between the methanol supply device and the methanol cracking reactor; the second flow valve is arranged on a first bypass pipeline, the input end of the first bypass pipeline is connected to the main supply pipeline between the first flow valve and the methanol cracking reactor, and the output end of the first bypass pipeline is connected to the main supply pipeline between the first flow valve and the methanol supply device; the third flow valve is arranged on the second bypass pipeline, the input end of the second bypass pipeline is connected to the main supply pipeline between the methanol supply device and the first flow valve, and the output end of the second bypass pipeline is connected to the methanol cracking reactor; the temperature sensing device and the pressure sensing device are both arranged in the methanol cracking reactor; the temperature sensing device is used to measure the real-time temperature in the methanol cracking reactor and transmit it to the control unit; the pressure sensing device is used to measure the real-time temperature in the methanol cracking reactor The control unit is used to control the first flow valve and the third flow valve to be opened simultaneously when the real-time temperature is greater than or equal to the preset temperature, so that the methanol flow rate sprayed from the methanol supply device into the methanol cracking reactor is equal to the preset flow rate; and when the real-time pressure of the methanol cracking reactor rises due to the generation of hydrogen, the opening of the third flow valve is reduced, so that the methanol flow rate sprayed from the methanol supply device into the methanol cracking reactor is equal to the preset flow rate; the control unit is also used to determine the time point with the maximum pressure increase rate according to the real-time pressure in the methanol cracking reactor, and determine the real-time temperature corresponding to the time point as the optimal reaction temperature; and open the second flow valve to adjust the temperature in the methanol cracking reactor by introducing methanol, so that the adjusted temperature in the methanol cracking reactor is equal to the optimal reaction temperature; the control unit is also used to increase the opening of the second flow valve when the real-time pressure decreases due to the start-up of the methanol engine to consume the hydrogen in the methanol cracking reactor, so that the methanol flow rate sprayed from the methanol supply device into the methanol cracking reactor is equal to the preset flow rate.
[0008] In a second aspect, the present application provides an on-vehicle methanol hydrogen production method, which is applied to the above-mentioned on-vehicle methanol hydrogen production system, and the on-vehicle methanol hydrogen production method includes: when the real-time temperature in the methanol cracking reactor is greater than or equal to the preset temperature, controlling the first flow valve and the third flow valve to be opened at the same time, so that the methanol flow rate injected into the methanol cracking reactor is equal to the preset flow rate; when the real-time pressure in the methanol cracking reactor rises due to the production of hydrogen in the methanol cracking reactor, reducing the opening of the third flow valve, so that the methanol flow rate injected into the methanol cracking reactor is equal to the preset flow rate; determining the time point when the pressure rise rate is the largest according to the real-time pressure in the methanol cracking reactor, and determining the real-time temperature corresponding to the time point as the optimal reaction temperature; opening the second flow valve, and adjusting the temperature in the methanol cracking reactor by introducing methanol, so that the adjusted temperature in the methanol cracking reactor is equal to the optimal reaction temperature; after the methanol engine is started, when the real-time pressure in the methanol cracking reactor decreases due to the consumption of hydrogen in the methanol cracking reactor, increasing the opening of the second flow valve, so that the methanol flow rate injected into the methanol cracking reactor is equal to the preset flow rate.
[0009] According to the specific embodiments provided in this application, this application discloses the following technical effects:
[0010] The present application provides a vehicle-mounted methanol hydrogen production system and method, wherein a first flow valve, a second flow valve and a third flow valve are respectively arranged on a main supply pipeline, a first bypass pipeline and a second bypass pipeline connected between a methanol supply device and a methanol cracking reactor, and a control unit adjusts the opening of the third flow valve according to the real-time pressure in the methanol cracking reactor to maintain a constant methanol injection flow rate under pressure changes, thereby achieving stability and uniformity of methanol injection; the control unit also determines the optimal reaction temperature according to the real-time pressure in the methanol cracking reactor, and adjusts the second flow valve, and realizes heat exchange by introducing methanol into the methanol cracking reactor, thereby adjusting the temperature in the methanol cracking reactor, maintaining the optimal reaction temperature in the methanol cracking reactor, and improving the efficiency of hydrogen production by methanol cracking. BRIEF DESCRIPTION OF THE DRAWINGS
[0011] 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 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.
[0012] Figure 1 This is a working principle diagram of a vehicle-mounted methanol hydrogen production system in one embodiment of the present application;
[0013] Figure 2A schematic diagram of a process for producing hydrogen from methanol on a vehicle provided in one embodiment of the present application;
[0014] Figure 3 A simplified schematic diagram of a vehicle-mounted methanol hydrogen production method provided in one embodiment of the present application. DETAILED DESCRIPTION
[0015] 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.
[0016] In order to make the above-mentioned objects, features and advantages of the present application more obvious and easy to understand, the present application is further described in detail below with reference to the accompanying drawings and specific implementation methods.
[0017] In an exemplary embodiment, Figure 1 As shown, a vehicle-mounted methanol hydrogen production system is provided, including: a methanol supply device, a methanol cracking reactor, a first flow valve, a second flow valve, a third flow valve, a control unit, a temperature sensor device and a pressure sensor device.
[0018] The first flow valve is arranged on the main supply pipeline connected between the methanol supply device and the methanol cracking reactor; the second flow valve is arranged on the first bypass pipeline, the input end of the first bypass pipeline is connected to the main supply pipeline between the first flow valve and the methanol cracking reactor, and the output end of the first bypass pipeline is connected to the main supply pipeline between the first flow valve and the methanol supply device; the third flow valve is arranged on the second bypass pipeline, the input end of the second bypass pipeline is connected to the main supply pipeline between the methanol supply device and the first flow valve, and the output end of the second bypass pipeline is connected to the methanol cracking reactor; the temperature sensing device and the pressure sensing device are both arranged in the methanol cracking reactor.
[0019] The temperature sensing device is used to measure the real-time temperature in the methanol cracking reactor and transmit it to the control unit; the pressure sensing device is used to measure the real-time pressure in the methanol cracking reactor and transmit it to the control unit.
[0020] The control unit is used to control the first flow valve and the third flow valve to open simultaneously when the real-time temperature is greater than or equal to the preset temperature, so that the methanol flow rate sprayed from the methanol supply device into the methanol cracking reactor is equal to the preset flow rate; and when the real-time pressure of the methanol cracking reactor rises due to the production of hydrogen, reduce the opening of the third flow valve, so that the methanol flow rate sprayed from the methanol supply device into the methanol cracking reactor is equal to the preset flow rate.
[0021] The control unit is also used to determine the time point when the pressure rise rate is the largest according to the real-time pressure in the methanol cracking reactor, and determine the real-time temperature corresponding to the time point as the optimal reaction temperature; and open the second flow valve to adjust the temperature in the methanol cracking reactor by introducing methanol, so that the adjusted temperature in the methanol cracking reactor is equal to the optimal reaction temperature.
[0022] The control unit is also used to increase the opening of the second flow valve when the real-time pressure decreases due to the start-up of the methanol engine to consume the hydrogen in the methanol cracking reactor, so that the methanol flow rate injected into the methanol cracking reactor from the methanol supply device is equal to the preset flow rate.
[0023] The present application solves the problem of uneven injection caused by unstable flow rate during methanol injection, achieves stability and uniformity of methanol injection, maintains the optimal temperature of methanol cracking reaction, ensures the efficiency of methanol cracking to produce hydrogen, and improves the economic efficiency of methanol use.
[0024] Figure 1 This is a working principle diagram of a vehicle-mounted methanol hydrogen production system. Figure 1 In the figure, V1 refers to the first flow valve, V2 refers to the second flow valve, V3 refers to the third flow valve, T refers to the temperature sensing device, and P refers to the pressure sensing device.
[0025] In another exemplary embodiment of the present application, the methanol supply device includes: a methanol tank and a methanol pump. A first flow valve is arranged on the main supply pipeline connected between the methanol tank and the methanol cracking reactor, and the methanol pump is arranged on the main supply pipeline between the methanol tank and the first flow valve; an input end of the first bypass pipeline is connected to the main supply pipeline between the first flow valve and the methanol cracking reactor, and an output end of the first bypass pipeline is connected to the main supply pipeline between the methanol tank and the methanol pump; an input end of the second bypass pipeline is connected to the main supply pipeline between the methanol pump and the first flow valve, and an output end of the second bypass pipeline is connected to the methanol cracking reactor.
[0026] In another exemplary embodiment of the present application, the vehicle-mounted methanol hydrogen production system further includes: a methanol injection device. One end of the main supply pipeline is connected to the methanol supply device, and the other end of the main supply pipeline is connected to the methanol injection device; the injection port of the methanol injection device is aimed at the methanol cracking reactor.
[0027] In another exemplary embodiment of the present application, the vehicle-mounted methanol hydrogen production system further includes: a fourth flow valve. The fourth flow valve is arranged on the hydrogen transmission pipeline connected between the hydrogen output end of the methanol cracking reactor and the methanol engine.
[0028] Figure 1 V4 in the figure refers to the fourth flow valve, H2 is hydrogen. The fourth flow valve can adjust the flow of hydrogen transmitted from the methanol cracking reactor to the methanol engine.
[0029] In another exemplary embodiment of the present application, the methanol cracking reactor is provided with a methanol output port, which is connected to the main supply pipeline between the methanol transmission pipeline and the methanol tank and the methanol pump.
[0030] In another exemplary embodiment of the present application, the vehicle-mounted methanol hydrogen production system further includes: a heating plate and a control switch. The heating plate is arranged in the methanol cracking reactor; the heating plate is connected to the power battery of the vehicle, and the control switch is arranged on the circuit connected between the heating plate and the power battery of the vehicle; before the methanol engine is cold-started, the control unit turns on the control switch so that the power battery supplies power to the heating plate to heat the methanol cracking reactor.
[0031] In another exemplary embodiment of the present application, the control unit is also used to control the start and stop of the methanol engine.
[0032] In another exemplary embodiment of the present application, the temperature sensing device is a temperature sensor, and the pressure sensing device is a pressure sensor.
[0033] In another exemplary embodiment of the present application, the preset temperature is 250° C. and the preset flow rate is 21 kg / h.
[0034] Reference Figure 1 The main working principle of the vehicle-mounted methanol hydrogen production system of this application is as follows:
[0035] Before the engine is cold started, the methanol cracking reactor is heated by the power battery. When the temperature inside the methanol cracking reactor reaches 250°C (this set temperature can be set according to the requirements of different OEMs, and this temperature range is not limited), the control unit will control the methanol pump, flow valve 1 and flow valve 3 to open at the same time. Under the action of flow valve 1 and flow valve 3, the initial methanol flow rate is 21kg / h (this set flow rate can be set according to the requirements of different OEMs, and this flow rate range is not limited).
[0036] Once methanol is injected into the methanol cracking reactor, hydrogen will be produced under the action of the catalyst. At this time, the pressure in the methanol cracking reactor will rise rapidly. Therefore, in order to ensure the stability of the methanol flow rate, the input methanol flow rate will be kept stable through the joint action of flow valve 1 and flow valve 2.
[0037] Flow valve 1 is on the main methanol supply pipeline, maintaining a constant flow rate (this flow rate will always be greater than 21kg / h); flow valve 3 is set on the second bypass pipeline to adjust the methanol flow rate entering the methanol cracking reactor. When the pressure in the methanol cracking reactor rises, the opening of flow valve 3 is reduced, the bypass methanol flow rate is reduced, and the flow rate entering the methanol cracking reactor is always kept consistent; and when the methanol engine is started, the hydrogen in the methanol cracking reactor will cause the pressure in the methanol cracking reactor to drop sharply due to a large amount of consumption. At this time, the opening of flow valve 2 is increased, and the bypass methanol flow rate is increased to ensure that the flow rate entering the methanol cracking reactor is maintained at 21kg / h. This system can ensure the stability of the methanol flow rate of the methanol injection device, thereby achieving uniform and stable methanol injection, which does not change with the pressure change in the methanol cracking reactor.
[0038] In addition, the optimal temperature of the methanol cracking reaction is determined by measuring the pressure rise rate in the methanol cracking reactor. After confirming the optimal reaction temperature of methanol, the flow valve 2 is opened to introduce methanol into the methanol cracking reactor through the pipeline to achieve heat exchange. The main purpose is to adjust the temperature in the reactor, prevent the temperature from continuing to rise, and reduce the methanol cracking hydrogen production reaction rate.
[0039] The present application can ensure that the flow rate of methanol injection is maintained under pressure changes, thereby achieving stability and uniformity of methanol injection; at the same time, the optimal reaction stability of the methanol cracking reaction is calculated, and the optimal reaction temperature in the reactor is maintained by increasing the methanol bypass to improve the reaction efficiency. In addition, the economic efficiency of methanol use can be improved and the use cost can be reduced.
[0040] Based on the same inventive concept, the embodiment of the present application also provides a vehicle-mounted methanol hydrogen production method that can be applied to the vehicle-mounted methanol hydrogen production system involved above. The implementation solution provided by the method to solve the problem is similar to the implementation solution recorded in the above system, so the specific limitations in one or more vehicle-mounted methanol hydrogen production method embodiments provided below can refer to the above limitations on the vehicle-mounted methanol hydrogen production system, and will not be repeated here.
[0041] In an exemplary embodiment, Figure 2 As shown, a method for producing hydrogen from methanol on a vehicle is provided, comprising the following steps 101 to 105. Among them:
[0042] Step 101: When the real-time temperature in the methanol cracking reactor is greater than or equal to the preset temperature, the first flow valve and the third flow valve are controlled to be opened simultaneously, so that the flow rate of methanol injected into the methanol cracking reactor is equal to the preset flow rate.
[0043] Step 102: When the real-time pressure in the methanol cracking reactor rises due to the generation of hydrogen in the methanol cracking reactor, the opening of the third flow valve is reduced so that the flow rate of methanol injected into the methanol cracking reactor is equal to the preset flow rate.
[0044] Step 103: determining the time point at which the pressure rise rate is the largest according to the real-time pressure in the methanol cracking reactor, and determining the real-time temperature corresponding to the time point as the optimal reaction temperature.
[0045] Step 104: Open the second flow valve and adjust the temperature in the methanol cracking reactor by introducing methanol, so that the adjusted temperature in the methanol cracking reactor is equal to the optimal reaction temperature.
[0046] Step 105: After the methanol engine is started, when the real-time pressure in the methanol cracking reactor decreases due to consumption of hydrogen in the methanol cracking reactor, the opening of the second flow valve is increased so that the flow rate of methanol injected into the methanol cracking reactor is equal to the preset flow rate.
[0047] Figure 3 The figure is a simplified flow chart of a vehicle-mounted methanol hydrogen production method. Figure 3 The preset temperature is 250° C. and the preset flow rate is 21 kg / h. ECU (Electronic Control Unit) is the control unit in this application.
[0048] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.
[0049] This article uses specific examples to illustrate the principles and implementation methods of this application. The description of the above embodiments is only used to help understand the method and core ideas of this application. At the same time, for those skilled in the art, according to the ideas of this application, there will be changes in the specific implementation methods and application scope. In summary, the content of this specification should not be understood as limiting this application.
Claims
1. A vehicle-mounted methanol hydrogen production system, characterized in that: The vehicle-mounted methanol hydrogen production system comprises: a methanol supply device, a methanol cracking reactor, a first flow valve, a second flow valve, a third flow valve, a control unit, a temperature sensor device and a pressure sensor device; The first flow valve is arranged on the main supply pipeline connected between the methanol supply device and the methanol cracking reactor; the second flow valve is arranged on the first bypass pipeline, the input end of the first bypass pipeline is connected to the main supply pipeline between the first flow valve and the methanol cracking reactor, and the output end of the first bypass pipeline is connected to the main supply pipeline between the first flow valve and the methanol supply device; the third flow valve is arranged on the second bypass pipeline, the input end of the second bypass pipeline is connected to the main supply pipeline between the methanol supply device and the first flow valve, and the output end of the second bypass pipeline is connected to the methanol cracking reactor; the temperature sensor device and the pressure sensor device are both arranged in the methanol cracking reactor; The temperature sensor device is used to measure the real-time temperature in the methanol cracking reactor and transmit it to the control unit; the pressure sensor device is used to measure the real-time pressure in the methanol cracking reactor and transmit it to the control unit; The control unit is used to control the first flow valve and the third flow valve to be opened simultaneously when the real-time temperature is greater than or equal to the preset temperature, so that the methanol flow rate sprayed from the methanol supply device into the methanol cracking reactor is equal to the preset flow rate; and when the real-time pressure of the methanol cracking reactor rises due to the generation of hydrogen, reduce the opening of the third flow valve, so that the methanol flow rate sprayed from the methanol supply device into the methanol cracking reactor is equal to the preset flow rate; The control unit is also used to determine the time point at which the pressure rise rate is the largest according to the real-time pressure in the methanol cracking reactor, and determine the real-time temperature corresponding to the time point as the optimal reaction temperature; and open the second flow valve to adjust the temperature in the methanol cracking reactor by introducing methanol, so that the adjusted temperature in the methanol cracking reactor is equal to the optimal reaction temperature; The control unit is also used to increase the opening of the second flow valve when the real-time pressure decreases due to the start-up of the methanol engine to consume the hydrogen in the methanol cracking reactor, so that the methanol flow rate injected into the methanol cracking reactor from the methanol supply device is equal to the preset flow rate.
2. The vehicle-mounted methanol hydrogen production system according to claim 1, characterized in that: The methanol supply device comprises: a methanol tank and a methanol pump; The first flow valve is arranged on the main supply pipeline connected between the methanol tank and the methanol cracking reactor, and the methanol pump is arranged on the main supply pipeline between the methanol tank and the first flow valve; The input end of the first bypass pipeline is connected to the main supply pipeline between the first flow valve and the methanol cracking reactor, and the output end of the first bypass pipeline is connected to the main supply pipeline between the methanol tank and the methanol pump; The input end of the second bypass pipeline is connected to the main supply pipeline between the methanol pump and the first flow valve, and the output end of the second bypass pipeline is connected to the methanol cracking reactor.
3. The vehicle-mounted methanol hydrogen production system according to claim 1, characterized in that: The vehicle-mounted methanol hydrogen production system further includes: a methanol injection device; One end of the main supply pipeline is connected to the methanol supply device, and the other end of the main supply pipeline is connected to the methanol injection device; the injection port of the methanol injection device is aimed at the methanol cracking reactor.
4. The vehicle-mounted methanol hydrogen production system according to claim 1, characterized in that: The vehicle-mounted methanol hydrogen production system further includes: a fourth flow valve; The fourth flow valve is arranged on the hydrogen transmission pipeline connected between the hydrogen output end of the methanol cracking reactor and the methanol engine.
5. The vehicle-mounted methanol hydrogen production system according to claim 2, characterized in that: The methanol cracking reactor is provided with a methanol output port; The methanol output port is through the methanol transmission pipeline and the main supply pipeline between the methanol tank and the methanol pump.
6. The vehicle-mounted methanol hydrogen production system according to claim 1, characterized in that: The vehicle-mounted methanol hydrogen production system also includes: a heating plate and a control switch; The heating plate is arranged in the methanol cracking reactor; The heating plate is connected to the power battery of the vehicle, and the control switch is arranged on the circuit connected between the heating plate and the power battery of the vehicle; Before the methanol engine is cold-started, the control unit turns on the control switch to allow the power battery to supply power to the heating plate to heat the methanol cracking reactor.
7. The vehicle-mounted methanol hydrogen production system according to claim 1, characterized in that: The control unit is also used to control the start and stop of the methanol engine.
8. The vehicle-mounted methanol hydrogen production system according to claim 1, characterized in that: The temperature sensing device is a temperature sensor, and the pressure sensing device is a pressure sensor.
9. The vehicle-mounted methanol hydrogen production system according to claim 1, characterized in that: The preset temperature is 250° C., and the preset flow rate is 21 kg / h.
10. A vehicle-mounted methanol hydrogen production method, characterized in that: The vehicle-mounted methanol hydrogen production method is applied to the vehicle-mounted methanol hydrogen production system according to any one of claims 1 to 9, and the vehicle-mounted methanol hydrogen production method comprises: When the real-time temperature in the methanol cracking reactor is greater than or equal to the preset temperature, the first flow valve and the third flow valve are controlled to be opened simultaneously so that the flow rate of methanol injected into the methanol cracking reactor is equal to the preset flow rate; When the real-time pressure in the methanol cracking reactor rises due to the production of hydrogen in the methanol cracking reactor, reducing the opening of the third flow valve so that the flow rate of methanol injected into the methanol cracking reactor is equal to the preset flow rate; Determine the time point at which the pressure rise rate is the largest according to the real-time pressure in the methanol cracking reactor, and determine the real-time temperature corresponding to the time point as the optimal reaction temperature; Opening the second flow valve, and adjusting the temperature in the methanol cracking reactor by introducing methanol, so that the adjusted temperature in the methanol cracking reactor is equal to the optimal reaction temperature; After the methanol engine is started, when the real-time pressure in the methanol cracking reactor decreases due to consumption of hydrogen in the methanol cracking reactor, the opening of the second flow valve is increased so that the methanol flow rate injected into the methanol cracking reactor is equal to the preset flow rate.