Device for increasing temperature of tail gas of hydrogen internal combustion engine and enhancing pressurization

Abstract

The utility model relates to the technical field of hydrogen internal combustion engines, in particular to a device for increasing tail gas temperature of a hydrogen internal combustion engine and enhancing pressurization. Comprising the steps that an exhaust hydrogen combustion device and an electronic control unit are additionally arranged on an original exhaust manifold of an internal combustion engine, an auxiliary combustion chamber is installed on the upstream of a turbocharger, the oxygen exhaust flow is calculated through an exhaust flow sensor and an oxygen concentration sensor, the hydrogen spraying flow of a hydrogen nozzle is determined, and hydrogen-air mixed gas is ignited through a sparking plug; therefore, the tail gas enthalpy value of an inlet of the turbocharger is increased through combustion of hydrogen in the auxiliary combustion chamber, the supercharge ratio is increased, and then the inflation efficiency and the power density of the hydrogen internal combustion engine are improved.

Description

Technical Field

[0001] This utility model relates to a temperature-enhanced boosting device, and more particularly to a device that uses exhaust pipe-assisted combustion to regulate the enthalpy of exhaust gas in a hydrogen internal combustion engine, thereby improving the boosting capability of the turbocharger in a hydrogen internal combustion engine, belonging to the field of hydrogen internal combustion engines. Background Technology

[0002] Hydrogen internal combustion engines can be produced by relying on most links of the traditional internal combustion engine industry chain. They have advantages such as low cost, high reliability, and wide environmental adaptability, and are one of the important technologies for the internal combustion engine industry to achieve the "dual carbon" goal.

[0003] Compared to traditional internal combustion engines, one of the key challenges in the development of hydrogen internal combustion engines is their significantly lower power density compared to gasoline and diesel engines. Currently, the power output per liter of a hydrogen internal combustion engine under reliable operating conditions is only about one-third that of a gasoline engine. This means that for the same power requirements, the size and weight of a hydrogen internal combustion engine will be significantly higher than that of a traditional internal combustion engine, increasing the complexity of vehicle powertrain layout and causing a decrease in overall vehicle efficiency.

[0004] The main reasons for the reduced power density of hydrogen internal combustion engines are twofold: firstly, hydrogen internal combustion engines typically employ lean combustion technology to avoid abnormal combustion, making it difficult to effectively utilize the air in the intake; secondly, hydrogen burns faster than traditional fuels, and the use of lean combustion significantly lowers the exhaust gas temperature. Under low exhaust gas enthalpy conditions, turbochargers struggle to provide a higher boost ratio, leading to a decrease in the charging efficiency of hydrogen internal combustion engines and a noticeable reduction in power.

[0005] Increasing the boost ratio is a crucial way to improve the power density of internal combustion engines. Existing technologies for enhancing boost in hydrogen internal combustion engines mainly include using variable geometry turbochargers, multi-stage turbochargers, electric turbochargers, or mechanical superchargers. Electric turbochargers and mechanical superchargers cannot utilize exhaust heat for engine boosting; their operation requires additional power, leading to a decrease in overall powertrain efficiency. Variable geometry turbochargers are expensive and difficult to manufacture, and multi-stage turbochargers occupy significant space. Furthermore, the aforementioned two new turbocharging technologies still rely on the enthalpy of the hydrogen internal combustion engine's exhaust gas as an energy source. Under the low exhaust temperature conditions of hydrogen internal combustion engines, these new technologies are unlikely to significantly improve the boost ratio. Utility Model Content

[0006] The present invention aims to solve the above-mentioned defects and provide a device for increasing the exhaust gas temperature and enhancing the boost pressure of a hydrogen internal combustion engine.

[0007] To overcome the deficiencies in the background technology, the technical solution adopted by this utility model to solve its technical problem is as follows: This device for increasing the exhaust gas temperature and enhancing the boost pressure of a hydrogen internal combustion engine includes the original internal combustion engine, exhaust manifold, turbocharger, selective catalytic reduction (SCR) and ammonia escape catalyst. Its feature is the addition of an exhaust hydrogen combustion device and an electronic control unit. The exhaust hydrogen combustion device includes an exhaust flow sensor installed on the exhaust manifold and an exhaust manifold valve located downstream of the exhaust flow sensor. An auxiliary combustion chamber is installed on the exhaust manifold. The inlet and outlet of the auxiliary combustion chamber are respectively provided with an auxiliary combustion chamber intake valve and an auxiliary combustion chamber exhaust valve. In the auxiliary combustion chamber, an oxygen concentration sensor, a hydrogen nozzle and a spark plug are installed sequentially from upstream to downstream. The hydrogen cylinder and the hydrogen nozzle are connected by a pipeline, and a pressure reducer is provided on the pipeline.

[0008] The pipeline equipped with the auxiliary combustion chamber intake valve is connected to the exhaust manifold, and the connection point is located between the exhaust flow sensor and the exhaust manifold valve.

[0009] The pipeline equipped with the auxiliary combustion chamber exhaust valve is connected to the exhaust manifold, and the connection point is located between the exhaust manifold valve and the turbocharger.

[0010] The oxygen concentration sensor is installed upstream of the hydrogen nozzle, and the distance between the concentration sensor and the hydrogen nozzle is not less than 20 mm.

[0011] The spark plug is installed downstream of the hydrogen nozzle, and the distance between the spark plug and the hydrogen nozzle is no more than 18 mm.

[0012] The electronic control unit meets the requirement of calculating the exhaust molar flow rate [mol / s] based on the exhaust flow sensor;

[0013] The electronic control unit obtains the actual intake pressure signal a by communicating with the electronic control unit of the internal combustion engine body, or by connecting to the existing intake pressure sensor in the internal combustion engine.

[0014] The electronic control unit is connected to the auxiliary combustion chamber exhaust valve and controls the opening and closing of the auxiliary combustion chamber exhaust valve by sending an auxiliary combustion chamber exhaust valve control signal b.

[0015] The electronic control unit is connected to the spark plug and controls the spark plug to ignite by sending a spark plug control signal c.

[0016] The electronic control unit is connected to the hydrogen nozzle and controls the opening and closing of the hydrogen nozzle by sending a hydrogen nozzle signal d.

[0017] The electronic control unit is connected to the oxygen concentration sensor and obtains the oxygen concentration in the auxiliary combustion chamber by receiving the oxygen concentration signal e.

[0018] The electronic control unit is connected to the auxiliary combustion chamber intake valve and controls the opening and closing of the auxiliary combustion chamber intake valve by sending an auxiliary combustion chamber intake valve control signal n.

[0019] The electronic control unit is connected to the exhaust manifold valve and controls the opening and closing of the exhaust manifold valve by sending an exhaust manifold valve control signal m.

[0020] The electronic control unit is connected to the exhaust flow sensor and obtains the exhaust flow of the hydrogen internal combustion engine by receiving the exhaust flow signal t.

[0021] The beneficial effect of this invention is that, addressing the problem of low power density in hydrogen internal combustion engines caused by insufficient turbocharger capacity due to low exhaust gas temperature and enthalpy, this invention provides a device and method for enhancing turbocharger pressure by increasing exhaust gas temperature. This device adds an auxiliary combustion chamber upstream of the turbocharger to the original exhaust manifold of the internal combustion engine. By installing a hydrogen nozzle and spark plug within the auxiliary combustion chamber, hydrogen can be combusted using oxygen in the exhaust gas under lean combustion conditions of the hydrogen internal combustion engine. This increases the exhaust gas temperature and enthalpy at the turbocharger inlet, thereby increasing the turbocharger's work capacity. Compared to technologies such as electric turbochargers and multi-stage turbochargers, the device and method provided by this invention retain the original turbocharger system structure, offering advantages in both turbocharger efficiency and cost. Attached Figure Description

[0022] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0023] Figure 1 This is a schematic diagram of the structure of this utility model;

[0024] The components are: 1. Internal combustion engine; 2. Exhaust manifold valve; 3. Turbocharger; 4. Selective catalytic reduction (SCR); 5. Ammonia escape catalyst; 6. Auxiliary combustion chamber exhaust valve; 7. Spark plug; 8. Hydrogen injector; 9. Oxygen concentration sensor; 10. Exhaust flow sensor; 11. Electronic control unit; 12. Auxiliary combustion chamber intake valve; 13. Pressure regulator; 14. Hydrogen cylinder; 15. Exhaust manifold; 16. Auxiliary combustion chamber.

[0025] a. Actual intake pressure signal; b. Auxiliary combustion chamber exhaust valve control signal; c. Spark plug control signal; d. Hydrogen nozzle signal; e. Oxygen concentration signal; t. Exhaust flow rate signal; m. Exhaust manifold valve control signal; n. Auxiliary combustion chamber intake valve control signal. Detailed Implementation

[0026] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below in conjunction with the embodiments of this utility model. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. All other embodiments obtained by those skilled in the art without creative effort in accordance with the embodiments of the basic utility model are within the protection scope of this utility model.

[0027] like Figure 1 As shown, this device for enhancing boost pressure by increasing the exhaust gas temperature of a hydrogen internal combustion engine includes the original internal combustion engine 1, exhaust manifold 15, turbocharger 3, selective catalytic reduction (SCR) 4, and ammonia escape catalyst 5. An exhaust hydrogen combustion device and an electronic control unit 11 are added to the original structure. The exhaust hydrogen combustion device includes an exhaust flow sensor 10 installed on the exhaust manifold 15, an exhaust manifold valve 2 located downstream of the exhaust flow sensor 10, an auxiliary combustion chamber 16 installed on the exhaust manifold 15, and auxiliary combustion chamber intake valve 12 and auxiliary combustion chamber exhaust valve 6 respectively installed at the inlet and outlet of the auxiliary combustion chamber 16. In the auxiliary combustion chamber 16, an oxygen concentration sensor 9, a hydrogen nozzle 8, and a spark plug 7 are installed sequentially from upstream to downstream. A hydrogen cylinder 14 is connected to the hydrogen nozzle 8 via a pipeline, and a pressure reducer 13 is installed on the pipeline.

[0028] The pipeline equipped with the auxiliary combustion chamber intake valve 12 is connected to the exhaust manifold 15, and the connection point is located between the exhaust flow sensor 10 and the exhaust manifold valve 2.

[0029] The pipeline equipped with the auxiliary combustion chamber exhaust valve 6 is connected to the exhaust manifold 15, and the connection point is located between the exhaust manifold valve 2 and the turbocharger 3.

[0030] The oxygen concentration sensor 9 is installed upstream of the hydrogen nozzle 8, and the distance between the concentration sensor 9 and the hydrogen nozzle 8 is not less than 20 mm.

[0031] Spark plug 7 is installed downstream of hydrogen nozzle 8, and the distance between spark plug 7 and hydrogen nozzle 8 is no more than 18mm.

[0032] The electronic control unit 11 meets the requirement of calculating the exhaust molar flow rate [mol / s] based on the exhaust flow sensor 10;

[0033] The electronic control unit 11 obtains the actual intake pressure signal a by communicating with the electronic control unit of the internal combustion engine body, or by connecting to the existing intake pressure sensor in the internal combustion engine;

[0034] The electronic control unit 11 is connected to the auxiliary combustion chamber exhaust valve 6 and controls the opening and closing of the auxiliary combustion chamber exhaust valve 6 by sending an auxiliary combustion chamber exhaust valve control signal b.

[0035] The electronic control unit 11 is connected to the spark plug 7 and controls the spark plug 7 to ignite by sending a spark plug control signal c.

[0036] The electronic control unit 11 is connected to the hydrogen nozzle 8 and controls the opening and closing of the hydrogen nozzle 8 by sending a hydrogen nozzle signal d.

[0037] The electronic control unit 11 is connected to the oxygen concentration sensor 9 and obtains the oxygen concentration of the auxiliary combustion chamber 16 by receiving the oxygen concentration signal e;

[0038] The electronic control unit 11 is connected to the auxiliary combustion chamber intake valve 12 and controls the opening and closing of the auxiliary combustion chamber intake valve 12 by sending an auxiliary combustion chamber intake valve control signal n.

[0039] The electronic control unit 11 is connected to the exhaust manifold valve 2 and controls the opening and closing of the exhaust manifold valve 2 by sending an exhaust manifold valve control signal m.

[0040] The electronic control unit 11 is connected to the exhaust flow sensor 10 and obtains the exhaust flow of the hydrogen internal combustion engine by receiving the exhaust flow signal t.

[0041] A control method for a turbocharger that enhances exhaust gas temperature in a hydrogen internal combustion engine includes the following steps:

[0042] The electronic control unit 11 first detects the actual intake pressure signal a, and obtains the actual intake manifold pressure of the hydrogen internal combustion engine under the current operating conditions through the actual intake pressure signal a. p a Furthermore, the actual boost efficiency of the hydrogen internal combustion engine is calculated based on the actual pressure in the intake manifold. or , or Defined as the actual pressure in the intake manifold of an internal combustion engine under certain operating conditions. p a With design pressure p t The ratio when or When the pressure is not less than 0.9, the electronic control unit 11 determines that the hydrogen internal combustion engine turbocharging system can meet the turbocharging requirements. At this time, the electronic control unit 11 closes the auxiliary combustion chamber intake valve 12 by sending an auxiliary combustion chamber intake valve control signal n, closes the auxiliary combustion chamber exhaust valve 6 by sending an auxiliary combustion chamber exhaust valve control signal b, and opens the exhaust manifold valve 2 by sending an exhaust manifold valve control signal m. At this time, the exhaust gas discharged by the internal combustion engine 1 does not pass through the auxiliary combustion chamber 16 and is discharged outside the engine normally through the exhaust manifold 15. At the same time, the electronic control unit 11 stops sending the spark plug control signal c to stop the spark plug 7 from igniting, and stops sending the hydrogen nozzle signal d to close the hydrogen nozzle 8.

[0043] When the electronic control unit 11 calculates the actual boost efficiency of the hydrogen internal combustion engine based on the actual pressure signal a or When the pressure is less than 0.9, the electronic control unit 11 determines that the hydrogen internal combustion engine's turbocharging system cannot meet the turbocharging requirements. At this time, the electronic control unit 11 opens the auxiliary combustion chamber intake valve 12 by sending an auxiliary combustion chamber intake valve control signal n, opens the auxiliary combustion chamber exhaust valve 6 by sending an auxiliary combustion chamber exhaust valve control signal b, and closes the exhaust manifold valve 2 by sending an exhaust manifold valve control signal m. At this time, the exhaust gas discharged from the internal combustion engine 1 is discharged outside the engine through the auxiliary combustion chamber 16. The electronic control unit calculates the hydrogen internal combustion engine exhaust molar flow rate M by receiving the exhaust flow rate signal t. e [mol / s], and further obtain the oxygen molar concentration in the exhaust gas based on the oxygen concentration signal e. F The molar flow rate M of oxygen in the exhaust gas is further calculated according to Equation 1. o :

[0044] M o =M e *F (Formula 1);

[0045] To ensure stable combustion and low combustion noise in the auxiliary combustion chamber (16), a lean combustion mode is adopted in the auxiliary combustion chamber (16). The electronic control unit calculates the target injection flow rate of hydrogen according to Equation 2. M h :

[0046] M h =1.6M o (Formula 2);

[0047] After calculating M h Subsequently, the electronic control unit 11 controls the spark plug 7 to continuously ignite at a frequency of not less than 50Hz by sending a spark plug control signal c, and the continuous ignition time of the spark plug 7 is not less than 5 seconds. 0.1s after sending the spark plug control signal c, the electronic control unit 11 controls the hydrogen nozzle 8 to open by sending a hydrogen nozzle signal d and makes the hydrogen flow rate injected by the hydrogen nozzle 8 M. h At this time, hydrogen gas mixes and burns with oxygen in the exhaust gas in the auxiliary combustion chamber 16, which increases the temperature of the exhaust gas after it flows back to the exhaust manifold 15 from the outlet of the auxiliary combustion chamber 16. This provides the turbocharger 3 with a higher exhaust gas enthalpy, thereby improving the turbocharging efficiency of the hydrogen internal combustion engine.

[0048] This embodiment conducted the following experiments under various working conditions:

[0049] Experimental use according to Figure 1A hydrogen internal combustion engine equipped with a device for enhancing the exhaust gas temperature and boosting the turbocharger was subjected to bench tests. The basic operating conditions of the hydrogen internal combustion engine were 2000 r / min and 100% load pedal. To avoid knocking, the minimum excess air coefficient that the hydrogen internal combustion engine could use under the above basic operating conditions was 1.7. Under the above conditions, the effect of a device and method for enhancing the exhaust gas temperature and boosting the turbocharger of a hydrogen internal combustion engine on enhancing the turbocharger system of the hydrogen internal combustion engine was tested.

[0050] Under the above operating conditions, the electronic control unit 11 calculates the actual boost efficiency of the hydrogen internal combustion engine based on the obtained actual pressure signal a. or =0.68, the electronic control unit 11 opens the auxiliary combustion chamber intake valve 12 by sending the auxiliary combustion chamber intake valve control signal n, opens the auxiliary combustion chamber exhaust valve 6 by sending the auxiliary combustion chamber exhaust valve control signal b, closes the exhaust manifold valve 2 by sending the exhaust manifold valve control signal m, and controls the spark plug 7 to ignite continuously at a frequency of 50Hz for 5s by sending the spark plug control signal c. The electronic control unit 11 calculates the actual hydrogen injection quantity of 0.02mol / s based on the exhaust flow signal t, the oxygen concentration signal e, and formulas one and two. 0.1s after the spark plug 7 ignites, the electronic control unit 11 opens the hydrogen nozzle 8 by sending the hydrogen nozzle signal d and controls the hydrogen injection flow rate to be 0.02mol / s.

[0051] Experimental results show that after successful combustion in the auxiliary combustion chamber 16, the inlet temperature of the turbocharger 3 increases by 136K, the actual boost efficiency increases from 0.68 to 0.92, and the output power of the hydrogen internal combustion engine increases by 28.9%. This indicates that the device and method for enhancing boost by increasing the exhaust gas temperature of a hydrogen internal combustion engine provided by this invention can effectively improve the boost ratio and power density of the hydrogen internal combustion engine.

[0052] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present utility model, based on the technical solution and the inventive concept of the present utility model, should be included within the protection scope of the present utility model.

Claims

1. A device for enhancing boost pressure by increasing the exhaust gas temperature of a hydrogen internal combustion engine, comprising an existing internal combustion engine (1), an exhaust manifold (15), a turbocharger (3), a selective catalytic reduction (SCR) (4), and an ammonia escape catalyst (5), characterized in that: It also includes an additional exhaust hydrogen combustion device and an electronic control unit (11). The exhaust hydrogen combustion device includes an exhaust flow sensor (10) installed on the exhaust manifold (15) and an exhaust manifold valve (2) located downstream of the exhaust flow sensor (10). An auxiliary combustion chamber (16) is installed on the exhaust manifold (15). An auxiliary combustion chamber inlet valve (12) and an auxiliary combustion chamber exhaust valve (6) are respectively provided at the inlet and outlet of the auxiliary combustion chamber (16). In the auxiliary combustion chamber (16), an oxygen concentration sensor (9), a hydrogen nozzle (8) and a spark plug (7) are installed sequentially from upstream to downstream. The hydrogen nozzle (8) is connected to a hydrogen cylinder (14) through a pipeline. A pressure reducer (13) is provided on the pipeline.

2. The device for enhancing turbocharging by increasing the exhaust gas temperature of a hydrogen internal combustion engine as described in claim 1, characterized in that, The exhaust manifold (15) is connected to a pipeline with an auxiliary combustion chamber intake valve (12), and the connection point is located between the exhaust flow sensor (10) and the exhaust manifold valve (2).

3. The device for enhancing turbocharging by increasing the exhaust gas temperature of a hydrogen internal combustion engine as described in claim 1, characterized in that, The exhaust manifold (15) is connected to a pipeline with an auxiliary combustion chamber exhaust valve (6), and the connection point is located between the exhaust manifold valve (2) and the turbocharger (3).

4. The device for enhancing turbocharging by increasing the exhaust gas temperature of a hydrogen internal combustion engine as described in claim 1, characterized in that, The oxygen concentration sensor (9) is installed upstream of the hydrogen nozzle (8), and the distance between the concentration sensor (9) and the hydrogen nozzle (8) is not less than 20 mm.

5. The device for enhancing turbocharging by increasing the exhaust gas temperature of a hydrogen internal combustion engine as described in claim 1, characterized in that, The spark plug (7) is installed downstream of the hydrogen nozzle (8), and the distance between the spark plug (7) and the hydrogen nozzle (8) is no more than 18 mm.

6. The apparatus for enhancing turbocharging by increasing the exhaust gas temperature of a hydrogen internal combustion engine as described in claim 1, characterized in that, The electronic control unit (11) meets the requirement of calculating the exhaust molar flow rate [mol / s] based on the exhaust flow sensor (10); The electronic control unit (11) obtains the actual intake pressure signal a by communicating with the electronic control unit of the internal combustion engine body, or by connecting with the original intake pressure sensor in the internal combustion engine; The electronic control unit (11) is connected to the auxiliary combustion chamber exhaust valve (6) and controls the opening and closing of the auxiliary combustion chamber exhaust valve (6) by sending an auxiliary combustion chamber exhaust valve control signal b. The electronic control unit (11) is connected to the spark plug (7) and controls the spark plug (7) to ignite by sending a spark plug control signal c; The electronic control unit (11) is connected to the hydrogen nozzle (8) and controls the opening and closing of the hydrogen nozzle (8) by sending a hydrogen nozzle signal d. The electronic control unit (11) is connected to the oxygen concentration sensor (9) and obtains the oxygen concentration of the auxiliary combustion chamber (16) by receiving the oxygen concentration signal e; The electronic control unit (11) is connected to the auxiliary combustion chamber intake valve (12) and controls the opening and closing of the auxiliary combustion chamber intake valve (12) by sending an auxiliary combustion chamber intake valve control signal n. The electronic control unit (11) is connected to the exhaust manifold valve (2) and controls the opening and closing of the exhaust manifold valve (2) by sending an exhaust manifold valve control signal m. The electronic control unit (11) is connected to the exhaust flow sensor (10) and obtains the exhaust flow of the hydrogen internal combustion engine by receiving the exhaust flow signal t.

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