Hydrogen internal combustion engine and control method thereof
Through the combination of liquid ammonia tank and selective catalytic reducing device, the high gasification latent heat and low reactive activity of liquid ammonia are used to inhibit the premature combustion of hydrogen internal combustion engines, and catalytic reduction of nitrogen oxides in the exhaust pipeline, solving the problems of premature combustion and high emissions of hydrogen internal combustion engines, achieving higher power density and lower emissions.
Patent Information
- Application Number
- CN202510675818.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-05-23
- Publication Date
- 2025-08-15
AI Technical Summary
The problems of hydrogen internal combustion engines being prone to premature combustion and high nitrogen oxide emissions limit their power density and emission performance.
The combination of a liquid ammonia tank and a selective catalytic reducing device is used to communicate with the combustion chamber of the internal combustion engine through the liquid ammonia injection pipeline, and a low-temperature and low-reaction combustion atmosphere is formed by using the high gasification latent heat and low-reaction activity of liquid ammonia to inhibit premature combustion, and catalytic reduction reaction is carried out in the exhaust pipeline to reduce nitrogen oxide emissions.
Effectively reduce the incidence of premature combustion, increase the power density of hydrogen internal combustion engines, and reduce nitrogen oxide emissions to regulatory limits, simplify operational processes and reduce hardware costs.
Smart Images
Figure CN120487439A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the field of internal combustion engines and provides a hydrogen internal combustion engine and a control method thereof. Background Art
[0002] Against the backdrop of the "dual carbon" goals, hydrogen energy has garnered widespread attention due to its clean, environmentally friendly nature and potential in energy storage applications. Hydrogen internal combustion engines, a key hydrogen energy application, offer technical advantages over other automotive powertrains, such as lower operating costs and lower hydrogen purity requirements.
[0003] However, hydrogen's high reactivity makes hydrogen internal combustion engines prone to pre-ignition during operation, limiting their power density and, consequently, their practical application. Furthermore, high combustion temperatures lead to high levels of nitrogen oxides emitted by hydrogen internal combustion engines, making it difficult to meet relevant emission standards. Consequently, a selective catalytic reduction system is required to reduce emissions. Summary of the Invention
[0004] An embodiment of the present invention provides a hydrogen internal combustion engine to solve the defects of hydrogen internal combustion engines in related technologies, such as easy pre-ignition and high nitrogen oxide emissions.
[0005] An embodiment of the present invention also provides a method for controlling a hydrogen internal combustion engine.
[0006] A first embodiment of the present invention provides a hydrogen internal combustion engine, comprising: Hydrogen tanks; an internal combustion engine body, wherein an exhaust pipe is provided on the internal combustion engine body, and the hydrogen tank is in fluid communication with a combustion chamber of the internal combustion engine body; a liquid ammonia tank in fluid communication with the combustion chamber of the internal combustion engine body via a liquid ammonia injection pipeline; A selective catalytic reduction device is installed in the exhaust pipe.
[0007] According to one embodiment of the present invention, an air intake pipe is further provided on the internal combustion engine body; The hydrogen tank is provided with at least one of a hydrogen in-cylinder injection pipeline and a hydrogen intake injection pipeline; The hydrogen tank is in fluid communication with the combustion chamber of the internal combustion engine body through the hydrogen cylinder injection pipeline. and / or, The hydrogen tank is in fluid communication with the intake line through the hydrogen intake injection line.
[0008] According to one embodiment of the present invention, the hydrogen tank is in fluid communication with the hydrogen in-cylinder injection pipeline and the hydrogen intake injection pipeline via a hydrogen pressure reducing valve.
[0009] According to one embodiment of the present invention, a pump body is provided at the outlet of the liquid ammonia tank, and the pump body is fluidically connected to the combustion chamber of the internal combustion engine body through a liquid ammonia cylinder injection pipeline, and the pump body is fluidically connected to the exhaust pipeline through a liquid ammonia exhaust gas treatment pipeline.
[0010] According to one embodiment of the present invention, an ammonia slip catalyst is provided at the outlet of the selective catalytic reduction device.
[0011] According to one embodiment of the present invention, a pollutant sensor is provided at the outlet of the ammonia slip catalyst.
[0012] According to one embodiment of the present invention, a pre-ignition sensor is provided on the internal combustion engine body.
[0013] According to one embodiment of the present invention, a controller is further included, which is electrically connected to the hydrogen tank to control the injection timing and injection pulse width of the hydrogen in the hydrogen tank. The controller is also electrically connected to the liquid ammonia tank to control the injection timing and injection pulse width of the liquid ammonia.
[0014] A second embodiment of the present invention provides a method for controlling a hydrogen internal combustion engine as described above, comprising: injecting liquid ammonia into the combustion chamber of the internal combustion engine body; injecting hydrogen into a combustion chamber in the internal combustion engine body so that the calorific value of the hydrogen is greater than that of liquid ammonia; The nitrogen oxides in the combustion chamber of the internal combustion engine body are introduced into the selective catalytic reduction device through the exhaust pipe.
[0015] According to one embodiment of the present invention, the step of injecting hydrogen into the combustion chamber in the internal combustion engine body comprises: During a cold start or low load condition of the internal combustion engine, liquid ammonia is not injected into the combustion chamber of the internal combustion engine; When the internal combustion engine is under medium to high load conditions and the combustion chamber of the internal combustion engine is pre-ignited, injecting liquid ammonia into the combustion chamber of the internal combustion engine to suppress the pre-ignition; The step of passing nitrogen oxides in the combustion chamber of the internal combustion engine into the selective catalytic reduction device through the exhaust pipe comprises: When it is confirmed that the nitrogen oxide concentration exceeds the standard, increasing the flow rate of liquid ammonia injected into the selective catalytic reduction device; When it is confirmed that the pollutants discharged by the ammonia slip catalyst exceed the standard, reducing the flow rate of liquid ammonia injected into the selective catalytic reduction device; When the flow rate of liquid ammonia injected into the selective catalytic reducer is zero and the ammonia concentration exceeds the standard, the flow rate of liquid ammonia injected into the combustion chamber of the internal combustion engine body is reduced.
[0016] In a hydrogen internal combustion engine provided by an embodiment of the first aspect of the present invention, liquid ammonia, after being injected into the combustion chamber through an injection line, utilizes its high latent heat of vaporization to absorb heat within the cylinder, lowering the initial temperature within the combustion chamber and slowing the tendency of hydrogen to spontaneously ignite. The low reactivity of liquid ammonia suppresses abnormal spontaneous combustion of the hydrogen mixture, creating a "low-temperature, low-reactivity" combustion atmosphere, effectively reducing the incidence of pre-ignition and addressing the power density limitations of traditional hydrogen internal combustion engines caused by pre-ignition. Liquid ammonia directly undergoes a redox reaction with nitrogen oxides generated at high temperatures within the combustion chamber, reducing the amount of nitrogen oxides produced during combustion. A selective catalytic reduction (SCR) system uses liquid ammonia as a reducing agent, replacing traditional urea, to catalytically reduce nitrogen oxides in the exhaust gas. Combined with the end-of-line treatment of the ammonia slip catalyst, the exhaust gas nitrogen oxide concentration can ultimately be reduced to the regulatory limit. Hydrogen, as the primary fuel, leverages its high reactivity to ensure sufficient ignition of the liquid ammonia, avoiding misfires or unburned emissions caused by the low reactivity of ammonia fuel. Liquid ammonia serves as both a pre-ignition inhibitor and an emissions-reducing reducing agent. The system eliminates the need for additional urea storage and injection equipment, requiring only hydrogen and ammonia fuels, streamlining operations and reducing hardware costs. During cold starts and low loads, only hydrogen is injected to ensure combustion stability. Under medium and high loads, a pre-ignition sensor monitors and triggers liquid ammonia injection in real time, dynamically suppressing pre-ignition and enabling engine operation over a wider load range.
[0017] According to the control method of the hydrogen internal combustion engine provided by the embodiment of the second aspect of the present invention, the interference of liquid ammonia on the low-load combustion stability is avoided through the hierarchical control of the working conditions, and at the same time, a rapid response is given under working conditions with high risk of pre-ignition, and the pre-ignition suppression efficiency can be effectively improved. The high latent heat of vaporization of liquid ammonia is used to reduce the initial temperature in the cylinder, and combined with the low reactivity atmosphere, the dual mechanism suppresses the abnormal spontaneous combustion of hydrogen, so that the hydrogen internal combustion engine can operate stably in a higher load range. Liquid ammonia reacts directly with nitrogen oxides in the combustion chamber, reducing the amount of nitrogen oxides generated during the combustion process. The selective catalytic reduction device uses liquid ammonia instead of urea as a reducing agent, and the reaction does not need to go through the urea hydrolysis step, and the nitrogen oxide purification efficiency can be significantly improved. BRIEF DESCRIPTION OF THE DRAWINGS
[0018] In order to more clearly illustrate the technical solutions in the present invention or the prior art, a brief introduction is given below to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.
[0019] Figure 1 It is a schematic structural diagram of the hydrogen internal combustion engine provided by the present invention.
[0020] Figure 2 It is a schematic flow chart of the control method of the hydrogen internal combustion engine provided by the present invention.
[0021] Reference numerals: 100. Hydrogen tank; 102. Combustion chamber; 104. Exhaust line; 106. Liquid ammonia tank; 108. Liquid ammonia injection line; 110. Selective catalytic reducer; 112. Intake line; 114. Hydrogen in-cylinder injection line; 116. Hydrogen intake injection line; 118. Hydrogen pressure reducing valve; 120. Pump body; 122. Liquid ammonia in-cylinder injection line; 124. Liquid ammonia exhaust treatment line; 126. Ammonia slip catalyst; 128. Pollutant sensor; 130. Pre-ignition sensor. DETAILED DESCRIPTION
[0022] The following embodiments of the present invention are described in further detail with reference to the accompanying drawings and examples. The following examples are used to illustrate the present invention but are not intended to limit the scope of the present invention.
[0023] like Figure 1 As shown, the first embodiment of the present invention provides a hydrogen internal combustion engine, comprising: Hydrogen tank 100; An internal combustion engine body is provided with an exhaust pipe 104, and a hydrogen tank 100 is in fluid communication with a combustion chamber 102 of the internal combustion engine body; a liquid ammonia tank 106 in fluid communication with the combustion chamber 102 of the internal combustion engine body via a liquid ammonia injection line 108; The selective catalytic reduction device 110 is installed in the exhaust pipe 104 .
[0024] In the hydrogen internal combustion engine provided by the first embodiment of the present invention, liquid ammonia is injected into the combustion chamber 102 through the injection line. Its high latent heat of vaporization absorbs heat within the cylinder, lowering the initial temperature within the combustion chamber 102 and slowing the tendency of hydrogen to spontaneously ignite. The low reactivity of liquid ammonia suppresses abnormal spontaneous combustion of the hydrogen mixture, creating a "low-temperature, low-reactivity" combustion atmosphere, effectively reducing the incidence of pre-ignition and addressing the power density limitations of traditional hydrogen internal combustion engines caused by pre-ignition. Liquid ammonia directly undergoes a redox reaction with nitrogen oxides generated at high temperatures within the combustion chamber 102, reducing the amount of nitrogen oxides produced during combustion. The selective catalytic reduction unit 110 uses liquid ammonia as a reducing agent, replacing traditional urea, to catalytically reduce nitrogen oxides in the exhaust gas. Combined with the end-of-line treatment of the ammonia slip catalyst 126, the nitrogen oxide concentration in the exhaust gas can ultimately be reduced to the regulatory limit. Hydrogen, as the primary fuel, leverages its high reactivity to ensure sufficient ignition of the liquid ammonia, avoiding misfires or unburned emissions caused by the low reactivity of ammonia fuel. Liquid ammonia serves as both a pre-ignition inhibitor and an emissions-reducing reducing agent. The system eliminates the need for additional urea storage and injection equipment, requiring only hydrogen and ammonia fuel injection, streamlining operations and reducing hardware costs. During cold starts and low-load conditions, only hydrogen is injected to ensure combustion stability. Under medium- and high-load conditions, pre-ignition sensor 130 monitors and triggers liquid ammonia injection in real time, dynamically suppressing pre-ignition and enabling engine operation over a wider load range.
[0025] Please continue to see Figure 1 The core structure of the hydrogen internal combustion engine provided by the embodiment of the first aspect of the present invention includes four major components: a hydrogen tank 100, an internal combustion engine body, a liquid ammonia tank 106 and a selective catalytic reducer 110.
[0026] The hydrogen tank 100 is used to store gaseous or liquid hydrogen and is connected to the combustion chamber 102 of the internal combustion engine via a pipeline, serving as the primary fuel and providing a power source. In this embodiment of the present invention, the combustion chamber 102 may optionally be equipped with an auxiliary ignition device such as a spark plug or glow plug, or may not be equipped with any auxiliary ignition device.
[0027] The internal combustion engine body is configured with an exhaust pipe 104, and the combustion chamber 102 is connected to the hydrogen tank 100 and the liquid ammonia tank 106 through fluid pipelines respectively, so as to realize hydrogen combustion, work and exhaust emission.
[0028] The liquid ammonia tank 106 is connected to the combustion chamber 102 through an independent liquid ammonia injection pipeline 108. After the liquid ammonia in the tank is pressurized by the pump body 120, it can be injected into the combustion chamber 102 during the combustion process.
[0029] The selective catalytic reduction device 110 is installed in the exhaust pipe 104 and is linked to the liquid ammonia injection system to use liquid ammonia as a reducing agent to catalytically reduce nitrogen oxides in the exhaust gas.
[0030] According to one embodiment of the present invention, an air intake pipe 112 is further provided on the internal combustion engine body; The hydrogen tank 100 is provided with at least one of a hydrogen in-cylinder injection pipeline 114 and a hydrogen intake injection pipeline 116 ; The hydrogen tank 100 is in fluid communication with the combustion chamber 102 of the internal combustion engine through the hydrogen cylinder injection line 114. and / or, The hydrogen tank 100 is in fluid communication with the intake line 112 via a hydrogen intake injection line 116 .
[0031] In one embodiment of the present invention, a throttle valve and a flow sensor may be provided in the intake pipe 112, and the hydrogen intake duct injection line is connected upstream of the throttle valve to ensure that the hydrogen and air are fully mixed before the intake stroke; the in-cylinder injection line is directly injected into the combustion chamber 102 through a dedicated nozzle on the cylinder head.
[0032] The dual-injection path design expands the flexibility of hydrogen fuel supply. The single intake port injection structure is simple and easy to maintain, making it suitable for cost-sensitive civilian or light vehicles. The injection timing of the single direct injection is highly controllable, which can improve thermal efficiency. During mixed injection, intake port injection is used to ensure stability at low loads, and direct injection is superimposed at medium and high loads to increase power, taking into account wide operating conditions.
[0033] According to one embodiment of the present invention, the hydrogen tank 100 is in fluid communication with the hydrogen in-cylinder injection line 114 and the hydrogen intake injection line 116 via a hydrogen pressure reducing valve 118 .
[0034] In one embodiment of the present invention, the hydrogen pressure reducing valve 118 may be a proportional solenoid pressure reducing valve, and the output pressure may be automatically adjusted according to the injection mode.
[0035] Dual pressure regulation can adapt to different injection scenarios, improving the operating adaptability of hydrogen internal combustion engines. When using direct injection mode, it is suitable for high-load conditions. High-pressure injection achieves "small but precise" fuel supply, reducing the risk of pre-ignition while improving power density. When using port injection mode, it is suitable for low-load conditions. Low-pressure mixing reduces the pressure resistance requirements of the injection system, reducing costs, and pre-mixing uniformity improves combustion stability. The two modes can be switched dynamically to achieve the optimal balance between efficiency, cost, and stability.
[0036] According to one embodiment of the present invention, a pump body 120 is provided at the outlet of the liquid ammonia tank 106. The pump body 120 is fluidically connected to the combustion chamber 102 of the internal combustion engine body through a liquid ammonia cylinder injection pipeline 122. The pump body 120 is fluidically connected to the exhaust pipeline 104 through a liquid ammonia exhaust gas treatment pipeline 124.
[0037] In one embodiment of the present invention, pump 120 can be an electric high-pressure diaphragm pump, with the injection path switched by a three-way valve. Liquid ammonia is injected directly into combustion chamber 102 via a high-pressure line at the end of the compression stroke. Liquid ammonia is then injected upstream of exhaust pipe 104 via a low-pressure line, where it mixes thoroughly with the exhaust gas before entering selective catalytic reduction device 110.
[0038] The dual-path injection design realizes the synergistic effect of "pre-treatment + post-treatment" of liquid ammonia, using the heat absorption of liquid ammonia vaporization to reduce the temperature in the cylinder, and at the same time reducing the amount of nitrogen oxides generated during the combustion process through the high-temperature reduction reaction of ammonia and nitrogen oxides; by directly using liquid ammonia as a reducing agent to participate in the catalytic reduction reaction, the additional energy consumption of traditional urea that needs to be hydrolyzed into ammonia is avoided, the reaction efficiency is improved, and the fuel filling process is simplified.
[0039] According to one embodiment of the present invention, an ammonia slip catalyst 126 is provided at the outlet of the selective catalytic reduction device 110 .
[0040] In one embodiment of the present invention, the ammonia slip catalyst 126 can be a honeycomb cordierite substrate coated with a precious metal catalyst such as platinum or palladium, and installed at the end of the exhaust pipe 104 to catalyze the oxidation reaction of residual ammonia in the exhaust gas to generate harmless nitrogen and water. The reaction formula is: 4NH3+3O2→2N2+6H2O; The ammonia escape catalyst 126 serves as a terminal purification device of the system, solving the ammonia leakage problem that may exist in the traditional selective catalytic reduction unit 110. When excessive liquid ammonia is injected into the selective catalytic reduction unit 110, the ammonia escape catalyst 126 can capture unreacted ammonia to ensure that the ammonia concentration in the exhaust gas meets the emission standards. Combined with the feedback from the pollutant sensor 128, a full process control of "injection-reduction-escape treatment" can be formed to avoid secondary pollution and improve the environmental friendliness of the system.
[0041] According to one embodiment of the present invention, a pollutant sensor 128 is provided at the outlet of the ammonia slip catalyst 126 .
[0042] In one embodiment of the present invention, the pollutant sensor 128 may be a multi-gas integrated sensor that can simultaneously detect the concentration of nitrogen oxides and ammonia in the exhaust gas with high detection accuracy.
[0043] The pollutant sensor 128 provides the system with real-time emission feedback, supporting the controller to implement fine-tuning. The controller automatically increases the liquid ammonia injection amount of the selective catalytic reduction device 110 to enhance the efficiency of the catalytic reduction reaction; by preferentially reducing the ammonia injection amount of the selective catalytic reduction device 110, if it still exceeds the standard, the liquid ammonia injection amount in the cylinder is reversely adjusted and the engine load is reduced to avoid over-reliance on a single adjustment path; through a real-time data closed loop, the system can dynamically balance the emission reduction effect and ammonia consumption under different operating conditions. Compared with a fixed injection strategy, the utilization rate of liquid ammonia is improved.
[0044] According to one embodiment of the present invention, a pre-ignition sensor 130 is provided on the internal combustion engine body.
[0045] In one embodiment of the present invention, the pre-ignition sensor 130 may be a high-frequency pressure sensor or an ion current sensor, which is installed on the wall of the combustion chamber 102 to monitor pressure fluctuations or ion current changes in the combustion chamber 102 in real time, accurately capture pre-ignition signals (such as the early occurrence of abnormal pressure peaks), and transmit the data to the controller in real time.
[0046] The pre-ignition sensor 130 provides the system with real-time pre-ignition determination, enabling the controller to dynamically adjust the liquid ammonia injection strategy based on the pre-ignition intensity: When pre-ignition is detected, liquid ammonia injection into the cylinder is immediately triggered, and the high latent heat of vaporization of liquid ammonia is used to reduce the temperature in the cylinder. At the same time, the abnormal self-ignition tendency of the hydrogen mixture is suppressed through low reactivity, effectively reducing the occurrence rate of pre-ignition. The precise monitoring of the pre-ignition sensor 130 can prevent the engine from being forced to reduce the load due to pre-ignition, thereby improving the stability and power output capacity of the hydrogen internal combustion engine under medium and high load conditions.
[0047] According to one embodiment of the present invention, a controller is further included. The controller is electrically connected to the hydrogen tank 100 to control the injection timing and injection pulse width of the hydrogen in the hydrogen tank 100. The controller is also electrically connected to the liquid ammonia tank 106 to control the injection timing and injection pulse width of the liquid ammonia.
[0048] In one embodiment of the present invention, the controller integrates multiple input and output interfaces, receives signals from the pre-ignition sensor 130, the pollutant sensor 128, etc., and implements hydrogen injection control and liquid ammonia injection control through a preset PID control algorithm or fuzzy control logic.
[0049] Specifically, the controller can switch the injection mode (direct injection or port injection) according to the operating conditions (cold start / low load / medium-high load) and adjust the injection pressure and pulse width; The controller can also accurately control the in-cylinder injection amount through the liquid ammonia pump during medium and high load pre-ignition and adjust the injection flow of the selective catalytic reduction device 110 according to the exhaust nitrogen oxide concentration.
[0050] The closed-loop control of the controller realizes the intelligent coordination of fuel injection. Liquid ammonia is not sprayed during cold start and low load to avoid affecting combustion stability. Ammonia is precisely injected during pre-ignition at medium and high loads. Compared with traditional passive suppression schemes (such as delayed ignition), the response speed is faster and the energy loss is smaller. Nitrogen oxides are directly reduced by liquid ammonia in the cylinder. Combined with the exhaust gas treatment of the selective catalytic reduction device 110, a double barrier of "in-engine purification + external catalysis" is formed. Compared with a single after-treatment system, the emission reduction efficiency is improved. It can also ensure that the calorific value of hydrogen accounts for the dominant proportion, and use the high activity of hydrogen to ignite liquid ammonia, reducing unburned ammonia emissions, while avoiding the decrease in combustion efficiency caused by excessive liquid ammonia.
[0051] See also Figure 2 A second aspect of the present invention provides a method for controlling a hydrogen internal combustion engine as described above, comprising: Step 10, injecting liquid ammonia into the combustion chamber 102 of the internal combustion engine body; Step 20, injecting hydrogen into the combustion chamber 102 in the internal combustion engine body so that the calorific value of the hydrogen is greater than the calorific value of the liquid ammonia; In step 30 , nitrogen oxides in the combustion chamber 102 of the internal combustion engine are introduced into the selective catalytic reduction device 110 through the exhaust pipe 104 .
[0052] According to the control method of the hydrogen internal combustion engine provided by the embodiment of the second aspect of the present invention, the interference of liquid ammonia on the low-load combustion stability is avoided through the hierarchical control of the working conditions, and at the same time, a rapid response is given under working conditions with high risk of pre-ignition, and the pre-ignition suppression efficiency can be effectively improved. The high latent heat of vaporization of liquid ammonia is used to reduce the initial temperature in the cylinder, and combined with the low reactivity atmosphere, the dual mechanism suppresses the abnormal spontaneous combustion of hydrogen, so that the hydrogen internal combustion engine can operate stably in a higher load range. Liquid ammonia directly reacts with nitrogen oxides in the combustion chamber 102, reducing the amount of nitrogen oxides generated during the combustion process. The selective catalytic reducer 110 uses liquid ammonia instead of urea as a reducing agent, and the reaction does not need to go through the urea hydrolysis step, and the nitrogen oxide purification efficiency can be significantly improved.
[0053] Please continue to see Figure 2 The second embodiment of the present invention provides a hydrogen internal combustion engine control method, which achieves synergistic optimization of pre-ignition suppression and nitrogen oxide emission reduction through a time-sharing injection strategy and closed-loop feedback control. The specific steps are as follows: Step 10: Injecting liquid ammonia into the combustion chamber 102; The liquid ammonia cylinder injection is triggered only when the pre-ignition sensor 130 detects a pre-ignition signal (such as an abnormal pressure peak occurring early) under medium-to-high load conditions; Liquid ammonia is not injected during cold start and low load conditions to avoid affecting combustion stability.
[0054] Step 20: Inject hydrogen into the combustion chamber 102 to ensure that the calorific value of hydrogen is greater than that of liquid ammonia. It supports direct injection and port injection, either alone or in combination. Direct injection is suitable for high-load conditions, which can achieve precise fuel stratification; port injection is suitable for low-load conditions, which can be pre-mixed with air to form a uniform mixture.
[0055] Step 30: Pass nitrogen oxides into the selective catalytic reduction device 110 for treatment When the post-catalytic pollutant sensor 128 detects that the nitrogen oxide concentration exceeds the standard, additional liquid ammonia is injected into the exhaust pipe 104 through the liquid ammonia exhaust treatment pipeline 124 to enhance the reaction efficiency of the selective catalytic reduction device 110; if it is detected that the ammonia slip concentration exceeds the standard, the liquid ammonia injection amount of the selective catalytic reduction device 110 is preferentially reduced; if it still exceeds the standard, the liquid ammonia injection amount in the combustion chamber 102 is reduced in reverse, and the engine load is reduced.
[0056] The pollutant sensor 128 monitors the concentration of nitrogen oxides and ammonia in the exhaust gas in real time, forming a closed loop of "detection-adjustment-redetection".
[0057] According to one embodiment of the present invention, the step of injecting hydrogen into the combustion chamber 102 in the internal combustion engine body includes: During cold start and low load conditions of the internal combustion engine, liquid ammonia is not injected into the combustion chamber 102 of the internal combustion engine. When the internal combustion engine is in a medium to high load condition and the combustion chamber 102 of the internal combustion engine is pre-ignited, liquid ammonia is injected into the combustion chamber 102 of the internal combustion engine to suppress the pre-ignition; The step of passing nitrogen oxides in the combustion chamber 102 of the internal combustion engine into the selective catalytic reduction device 110 through the exhaust pipe 104 includes: When it is confirmed that the nitrogen oxide concentration exceeds the standard, the flow rate of liquid ammonia injected into the selective catalytic reduction device 110 is increased; When it is confirmed that the pollutants discharged from the ammonia slip catalyst 126 exceed the standard, the flow rate of liquid ammonia injected into the selective catalytic reduction device 110 is reduced; When the flow rate of liquid ammonia injected into the selective catalytic reduction device 110 is zero and the ammonia concentration exceeds the standard, the flow rate of liquid ammonia injected into the combustion chamber 102 of the internal combustion engine body is reduced.
[0058] In one embodiment of the present invention, the operating conditions of hydrogen and liquid ammonia injection are controlled in a hierarchical manner. Specifically: During cold start and low load conditions of the internal combustion engine, liquid ammonia is not injected into the combustion chamber 102 to ensure stable operation of the internal combustion engine. Under high-load conditions of the internal combustion engine, when the pre-ignition sensor 130 detects pre-ignition, liquid ammonia is injected into the combustion chamber 102 to suppress hydrogen activity by utilizing the high latent heat of vaporization and low reactivity of liquid ammonia to reduce the probability of hydrogen pre-ignition. When liquid ammonia is injected but the pre-ignition sensor 130 still detects pre-ignition, the flow rate of liquid ammonia injected into the combustion chamber 102 is increased to enhance the effect of suppressing pre-ignition; When the post-catalytic pollutant sensor 128 detects that the concentration of nitrogen oxides exceeds the emission regulatory standard, it increases the flow rate of liquid ammonia injected into the selective catalytic reducer 110, and uses the liquid ammonia to undergo an oxidation-reduction reaction with nitrogen oxides to consume nitrogen oxides in the exhaust gas; When the post-catalytic pollutant sensor 128 detects that the ammonia concentration exceeds the emission regulatory standard, the flow rate of liquid ammonia injected into the selective catalytic reduction device 110 is reduced to reduce the generation of unburned ammonia; When the flow rate of liquid ammonia injected into the selective catalytic reduction device 110 is zero and the ammonia concentration still exceeds the emission regulatory standard, the flow rate of liquid ammonia injected into the combustion chamber 102 is reduced and the engine power is reduced. By reducing the power, the frequency of pre-ignition is reduced, and the demand for liquid ammonia injection into the combustion chamber 102 is reduced, thereby reducing unburned ammonia emissions.
[0059] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the various embodiments of the present invention.
Claims
1. A hydrogen internal combustion engine, characterized in that: include: Hydrogen tank (100); An internal combustion engine body, wherein an exhaust pipe (104) is provided on the internal combustion engine body, and the hydrogen tank (100) is in fluid communication with a combustion chamber (102) of the internal combustion engine body; a liquid ammonia tank (106) in fluid communication with the combustion chamber (102) of the internal combustion engine body via a liquid ammonia injection pipeline (108); A selective catalytic reduction device (110) is installed in the exhaust pipe (104).
2. The hydrogen internal combustion engine according to claim 1, characterized in that The internal combustion engine body is also provided with an air intake pipe (112); The hydrogen tank (100) is provided with at least one of a hydrogen in-cylinder injection pipeline (114) and a hydrogen intake injection pipeline (116); The hydrogen tank (100) is in fluid communication with the combustion chamber (102) of the internal combustion engine body via the hydrogen cylinder injection pipeline (114). and / or, The hydrogen tank (100) is in fluid communication with the intake pipe (112) via the hydrogen intake injection pipe (116).
3. The hydrogen internal combustion engine according to claim 2, characterized in that The hydrogen tank (100) is in fluid communication with the hydrogen in-cylinder injection pipeline (114) and the hydrogen intake injection pipeline (116) via a hydrogen pressure reducing valve (118).
4. The hydrogen internal combustion engine according to claim 1, characterized in that A pump body (120) is provided at the outlet of the liquid ammonia tank (106); the pump body (120) is in fluid communication with the combustion chamber (102) of the internal combustion engine body via a liquid ammonia cylinder injection pipeline (122); and the pump body (120) is in fluid communication with the exhaust pipeline (104) via a liquid ammonia tail gas treatment pipeline (124).
5. The hydrogen internal combustion engine according to any one of claims 1 to 4, characterized in that An ammonia slip catalyst (126) is provided at the outlet of the selective catalytic reduction device (110).
6. The hydrogen internal combustion engine according to claim 5, characterized in that A pollutant sensor (128) is provided at the outlet of the ammonia slip catalyst (126).
7. The hydrogen internal combustion engine according to any one of claims 1 to 4, characterized in that A pre-ignition sensor (130) is provided on the internal combustion engine body.
8. The hydrogen internal combustion engine according to any one of claims 1 to 4, characterized in that The invention also includes a controller, which is electrically connected to the hydrogen tank (100) to control the injection timing and injection pulse width of the hydrogen in the hydrogen tank (100), and the controller is also electrically connected to the liquid ammonia tank (106) to control the injection timing and injection pulse width of the liquid ammonia.
9. A method for controlling a hydrogen internal combustion engine according to any one of claims 1 to 8, characterized in that: include: injecting liquid ammonia into the combustion chamber (102) of the internal combustion engine body; injecting hydrogen into a combustion chamber (102) in the internal combustion engine body so that the calorific value of the hydrogen is greater than that of liquid ammonia; The nitrogen oxides in the combustion chamber (102) of the internal combustion engine body are introduced into the selective catalytic reduction device (110) through the exhaust pipe (104).
10. The control method according to claim 9, characterized in that: The step of injecting hydrogen into the combustion chamber (102) in the internal combustion engine body comprises: When the internal combustion engine is cold started or under low-load conditions, liquid ammonia is not injected into the combustion chamber (102) of the internal combustion engine; When the internal combustion engine is in a medium to high load condition and the combustion chamber (102) of the internal combustion engine is pre-ignited, liquid ammonia is injected into the combustion chamber (102) of the internal combustion engine to suppress the pre-ignition; The step of passing nitrogen oxides in the combustion chamber (102) of the internal combustion engine body into the selective catalytic reduction device (110) through the exhaust pipe (104) comprises: When it is confirmed that the nitrogen oxide concentration exceeds the standard, increasing the flow rate of liquid ammonia injected into the selective catalytic reduction device (110); When it is confirmed that the pollutants discharged from the ammonia slip catalyst (126) exceed the standard, the flow rate of liquid ammonia injected into the selective catalytic reduction device (110) is reduced; When the flow rate of liquid ammonia injected into the selective catalytic reduction device (110) is zero and the ammonia concentration exceeds a standard, the flow rate of liquid ammonia injected into the combustion chamber (102) of the internal combustion engine body is reduced.