Air intake temperature stratification control air passage structure for ammonia fuel engine and temperature control method

Abstract

This invention discloses an intake air temperature stratification control duct structure and temperature control method for an ammonia fuel engine. The ammonia fuel engine is equipped with a fuel injection device that injects ammonia fuel into the intake manifold. The fuel injection device includes a storage tank, a first gas injection valve for connecting to the intake manifold, and a second gas injection device for connecting to a premixer. This invention, by incorporating an injection simulation component, can simulate the air-fuel ratio and air temperature at the time of fuel injection. It can also simulate, to a certain extent, the temperature drop of the liquid ammonia fuel itself and the degree of vaporization leading to the temperature decrease of the mixed gas. Based on this temperature drop, the temperature control components of each layer are controlled to compensate for the temperature drop in advance, ensuring that the target temperature of the mixed gas is maintained after the ammonia fuel is mixed.

Description

Technical Field

[0001] This invention relates to the field of ammonia fuel engines, and more specifically to an intake air temperature stratification control duct structure and temperature control method for an ammonia fuel engine. Background Technology

[0002] Ammonia is a carbon-free fuel with mature storage and transportation technology, high energy density, and no carbon dioxide emissions after combustion, thus eliminating greenhouse gas emissions. However, ammonia has a high auto-ignition temperature, extremely slow flame propagation speed, and high minimum ignition energy, making it difficult to compress or ignite. Therefore, the engine intake air temperature needs to be strictly controlled and adjusted according to the engine load and current operating conditions to achieve a sufficient combustion temperature.

[0003] Existing ammonia fuel temperature control systems typically employ multi-stage temperature control devices: intercooler bypass opening adjustment, EGR gas recovery heating, and electric heating. The target temperature is obtained by consulting a MAP chart based on operating conditions, and then each stage of the temperature control device is adjusted. The system monitors the temperature before the intake manifold to ensure the target temperature is reached and provides feedback. However, this approach has several drawbacks: it doesn't consider the ammonia fuel's own temperature and makes it difficult to determine the degree of ammonia fuel vaporization after injection. Liquid ammonia fuel absorbs a large amount of heat after vaporization, causing the mixture temperature to drop. Since existing ammonia fuel engines typically inject into the mixture through the intake manifold or via direct injection, there is almost no time for further temperature regulation. Adjustments can only be made by compensating for advance timing or based on exhaust gas feedback, resulting in low accuracy and slow response. Summary of the Invention

[0004] The purpose of this invention is to provide an intake temperature stratification control duct structure and temperature control method for an ammonia fuel engine, which solves the problem that existing duct temperature control does not take into account the influence of ammonia fuel itself.

[0005] The present invention achieves the above objectives through the following technical solutions: An intake air temperature stratification control passage structure for an ammonia fuel engine, comprising: The main air intake system includes the intake manifold, throttle body, exhaust manifold, and turbocharger. The first temperature control component is located between the intake manifold and the turbocharger, and includes the intercooler, the intercooler bypass branch, and the flow control valve. The second temperature control component includes an EGR recovery branch with a valve; The third temperature control component is used to regulate the intake air temperature via electric auxiliary heating; The injection simulation component is used to simulate injection conditions for fuel premixing and to obtain the temperature drop of the mixed gas. Based on the temperature drop and the target temperature obtained by querying the MAP chart, the temperature control components are used to adjust the temperature.

[0006] As a preferred embodiment of the present invention, the intercooler and the bypass branch of the intercooler are connected in parallel, and a second valve and a third valve are respectively provided on the intercooler branch and its bypass branch. This embodiment is the prior art. By adjusting the opening of the intercooler branch and its bypass branch, the air passing through the turbocharger is initially regulated.

[0007] As a preferred embodiment of the present invention, a first monitoring unit is provided at the junction of the intercooler and the bypass branch of the intercooler, and a second monitoring unit is provided at the junction of the junction and the EGR recovery branch. A third temperature control component is provided at the intake manifold inlet, and a third monitoring unit is also provided at the outlet of the third temperature control component. This embodiment monitors the temperature by setting monitoring units to provide feedback to the temperature control components at each stage.

[0008] As a preferred embodiment of the present invention, the EGR recovery branch includes a fourth valve and an EGR cooler connected in parallel with the fourth valve. The inlet or outlet of the EGR cooler is provided with a fifth valve. This embodiment further provides an EGR cooler, which has the same effect as an intercooler and its bypass branch, and performs temperature control on the high-temperature waste gas during the waste gas recovery process.

[0009] As a preferred embodiment of the present invention, the injection simulation component includes a premixer and a pair of fourth monitoring units disposed at the inlet and outlet of the premixer for obtaining the temperature reduction magnitude. The premixer is used to insert an injection valve to simulate gas mixing, and the air inlet of the premixer is connected to the compressed air outlet of the booster, and the outlet is connected to the inlet of the third temperature control component. Due to the temperature difference of ammonia fuel itself and the different degrees of vaporization at different air temperatures, it is difficult to predict the temperature after it is mixed with air at different temperatures. This embodiment specifically sets up an injection simulation component, which injects ammonia fuel by simulating air temperature and ratio, thereby obtaining the temperature reduction magnitude at the current temperature.

[0010] As a preferred embodiment of the present invention, the inlet of the turbocharger is further provided with a heat storage cylinder, and the exhaust gas of the exhaust manifold passes through the heat storage cylinder to exchange heat and store temperature on the inlet gas of the premixer. The inlet of the heat storage cylinder is also provided with a sixth valve for adjusting the flow rate. In this embodiment, the flow rate is adjusted by the sixth valve, which distributes air according to a preset air-fuel ratio. The heat storage cylinder is used to store air at the corresponding temperature so that it can be directly injected when prediction is needed.

[0011] As a preferred embodiment of the present invention, a waste channel is provided at the center of the storage cylinder, and several stepped temperature chambers are arranged around the exhaust gas channel. The temperature of the stepped temperature chambers gradually decreases from top to bottom according to the heat dissipation efficiency. Branch pipes are provided at both ends of the stepped temperature chambers. The branch pipes are used to introduce the turbocharger outlet air into the stepped temperature chambers and to collect it to the premixer. By setting up stepped temperature chambers, the air in the chambers decreases from top to bottom. When the air in the stepped temperature chambers enters the premixer, it can simulate the mixing situation at various temperatures in a short time and can obtain the temperature reduction of the mixed gas at the target temperature in a timely manner. The stepped temperature chambers store the air in layers based on the principle that the air itself has poor thermal conductivity. Furthermore, a porous structure can be set in the stepped temperature chambers to reduce the mutual flow of air and thus ensure uniform heat distribution.

[0012] As a preferred embodiment of the present invention, the exterior of the heat storage cylinder is provided with fins, and the contact area between the fins and the air gradually increases from top to bottom to enhance heat dissipation efficiency. This embodiment makes the temperature inside the heat storage cylinder gradually change by setting fins with varying areas.

[0013] As a preferred embodiment of the present invention, connecting pipes are provided at both ends of the exhaust gas passage, and a first bypass valve is also provided in parallel between the two connecting pipes. A fifth monitoring unit is provided in the middle part of the stepped temperature chamber. The first valve is used to adjust the opening of the exhaust gas bypass, thereby adjusting the exhaust flow rate in the exhaust gas passage, so as to control the middle temperature of the stepped temperature chamber at a preset value. In this embodiment, the bypass is performed by setting the first valve, and the flow rate into the exhaust gas passage is adjusted as needed when exhausting exhaust gas. A valve can also be set in the exhaust gas passage. The purpose is to maintain a stepped temperature in the heat storage cylinder, and the temperature range of the stepped temperature covers the target temperature required by the engine.

[0014] To implement the above-mentioned temperature stratification control airway structure, the present invention also proposes a temperature control method based on any of the above-mentioned intake temperature stratification control airway structures, comprising the following steps: S1: When the engine load or power demand changes, the ECU queries the MAP to obtain the target temperature and air-fuel ratio required for the changed operating conditions. The injection simulation component simulates the target temperature and air-fuel ratio to premix the fuel for the injection conditions and obtains the reduction in the temperature of the mixture. S2: Based on the temperature reduction rate and the target temperature, control each temperature control component to adjust the intake temperature layer by layer so that the temperature of the mixed gas reaches the target temperature; S3: When the engine load and power demand are stable, the injection simulation component shuts down and maintains the required target temperature.

[0015] The beneficial effects of the present invention are as follows: by setting up an injection simulation component, the present invention can simulate the air-fuel ratio and air temperature when the fuel injection valve is injected, and can simulate to a certain extent the temperature drop of the liquid ammonia fuel itself and the degree of vaporization of the mixed gas. Then, based on the temperature drop, the temperature control components of each layer are controlled to compensate the intake air temperature in advance, so that the target temperature of the mixed gas can still be maintained after the ammonia fuel is mixed. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the airway of the present invention; Figure 2 This is a three-dimensional schematic diagram of the heat storage cylinder of the present invention; Figure 3 This is a cross-sectional view of the heat storage cylinder of the present invention; Figure 4 This is a top view of the heat storage cylinder of the present invention; Figure 5 This is a schematic diagram of the airway according to the second embodiment of the present invention; Figure 6 This is a schematic diagram of the airway according to the third embodiment of the present invention; In the diagram: 1. Main intake manifold; 11. Turbocharger; 12. Intake manifold; 13. Exhaust manifold; 14. First valve; 15. First monitoring unit; 16. Second monitoring unit; 17. Throttle valve; 18. Third monitoring unit; 2. First temperature control unit; 21. Intercooler; 22. Second valve; 23. Third valve; 3. Second temperature control unit; 31. Fourth valve; 32. Fifth valve; 33. EGR cooler; 4. Third temperature control unit; 5. Injection simulation unit; 51. Heat storage tank; 52. Sixth valve; 53. Premixer; 54. Fourth monitoring unit; 55. Connecting pipe; 56. Branch pipe; 57. Fin; 58. Temperature chamber; 59. Fifth monitoring unit; 6. Fuel injection device; 61. Storage tank; 62. First injection valve; 63. Second injection valve; 7. Engine. Detailed Implementation

[0017] The present application will now be described in further detail with reference to the accompanying drawings. It should be noted that the following specific embodiments are only used to further illustrate the present application and should not be construed as limiting the scope of protection of the present application. Those skilled in the art can make some non-essential improvements and adjustments to the present application based on the above application content. The monitoring units in this document are used to monitor parameters such as temperature, air pressure, and flow rate as needed.

[0018] Example 1

[0019] like Figure 1-4As shown, an intake temperature stratification control air passage structure for an ammonia fuel engine 7 is provided. The ammonia fuel engine 7 is equipped with a fuel injection device 6 to inject ammonia fuel into the intake manifold 12. The fuel injection device 6 includes a storage tank 61, a first gas injection valve 62 for connecting to the intake manifold 12, and a second gas injection valve 63 for connecting to the premixer 53.

[0020] The air intake structure includes a main air intake duct 1, a first temperature control component 2, a second temperature control component 3, a third temperature control component 4, and an injection simulation component 5. The main air intake duct 1 includes an intake manifold 12, a throttle valve 17, an exhaust manifold 13, and a turbocharger 11. The first temperature control component 2 is located between the intake manifold 12 and the turbocharger 11 and includes an intercooler 21, a bypass branch of the intercooler 21, and a flow control valve. The second temperature control component 3 includes an EGR recovery branch with a valve. The third temperature control component 4 is used to regulate the intake air temperature through electric auxiliary heating. The injection simulation component 5 is used to simulate injection conditions for fuel premixing and to obtain the temperature reduction of the mixed gas. Based on the temperature reduction and the target temperature obtained by querying the MAP chart, it controls each temperature control component to adjust the temperature.

[0021] In this embodiment, by setting up an injection simulation component 5, it can simulate the air-fuel ratio and air temperature during the injection of fuel injection valve. It can simulate to a certain extent the temperature reduction of the liquid ammonia fuel itself and the degree of vaporization of the mixed gas. Then, based on the temperature reduction, the temperature control components of each layer are controlled to compensate the intake air temperature in advance so that the target temperature of the mixed gas can still be maintained after the ammonia fuel is mixed.

[0022] Specifically, during implementation, fuel premixing is performed by simulating injection conditions through injection simulation component 5. The temperature drop of the premixed gas mixture is used as a reference to adjust the valve opening of each layer of temperature control components, thereby ensuring that the air temperature entering the intake manifold 12 is higher than the target temperature. After mixing with ammonia fuel, the target temperature is reached, and the premixed gas mixture returns to the intake manifold 12 and enters the engine 7 for refueling.

[0023] Optionally, the intercooler 21 and its bypass branch are connected in parallel, and a second valve 22 and a third valve 23 are respectively provided on the intercooler 21 branch and its bypass branch. This embodiment is the prior art. By adjusting the opening of the intercooler 21 branch and its bypass branch, the air passing through the turbocharger 11 is initially regulated.

[0024] Preferably, a first monitoring unit 15 is provided at the junction of the intercooler 21 and the bypass branch of the intercooler 21, and a second monitoring unit 16 is provided at the junction of the junction and the EGR recovery branch. The third temperature control component 4 is provided at the inlet of the intake manifold 12, and a third monitoring unit 18 is also provided at the outlet of the third temperature control component 4. In this embodiment, the temperature is monitored by setting monitoring units to provide feedback to the temperature control components at each level.

[0025] Preferably, the injection simulation component 5 includes a premixer 53 and a pair of fourth monitoring units 54 disposed at the inlet and outlet of the premixer 53 for obtaining the temperature reduction magnitude. The premixer 53 is used to insert the injection valve to simulate gas mixing, and the air inlet of the premixer 53 is connected to the compressed air outlet of the booster 11, and the outlet is connected to the inlet of the third temperature control component 4. The temperature difference of ammonia fuel itself and the different degree of vaporization at different air temperatures make it difficult to predict the temperature after it is mixed with air at different temperatures. This solution specifically sets up the injection simulation component 5, which injects ammonia fuel by simulating the air temperature and ratio, thereby obtaining the temperature reduction magnitude at the current temperature.

[0026] Preferably, the inlet of the turbocharger 11 is also provided with a heat storage cylinder 51. The exhaust gas from the exhaust manifold 13 passes through the heat storage cylinder 51 to exchange heat with and store the inlet gas of the premixer 53. The inlet of the heat storage cylinder 51 is also provided with a sixth valve 52 for adjusting the flow rate. In this embodiment, the flow rate is further adjusted by the sixth valve 52. The sixth valve 52 is directly closed when premixing and temperature control are not required. When the operating conditions need to be changed, it distributes air according to the preset air-fuel ratio. The heat storage cylinder 51 is used to store air at the corresponding temperature so that it can be directly injected when prediction is needed.

[0027] Preferably, a waste channel is provided at the center of the storage cylinder 51, and several stepped temperature chambers 58 are arranged around the exhaust gas channel. The temperature of the stepped temperature chambers 58 gradually decreases from top to bottom according to the heat dissipation efficiency. Branch pipes 56 are provided at both ends of the stepped temperature chambers 58. The branch pipes 56 are used to introduce the air from the outlet of the booster 11 into the stepped temperature chambers 58 and to collect it to the premixer 53. In this scheme, by setting the stepped temperature chambers 58, the air in them decreases from top to bottom. When the air in the stepped temperature chambers 58 enters the premixer 53, it can simulate the mixing situation at various temperatures in a short time and can obtain the temperature reduction of the mixed gas at the target temperature in a timely manner. The stepped temperature chambers 58 are layered and stored according to the principle that the thermal conductivity of air is poor. A porous structure can be set in the stepped temperature chambers to reduce the mutual flow of air and thus reduce heat uniformity.

[0028] Preferably, the exterior of the heat storage cylinder 51 is provided with fins 57, and the contact area between the fins 57 and the air gradually increases from top to bottom to enhance heat dissipation efficiency. This solution makes the temperature inside the heat storage cylinder 51 gradually change by setting fins with varying areas.

[0029] Preferably, connecting pipes 55 are provided at both ends of the exhaust gas passage, and a first bypass valve 14 is also provided in parallel between the two connecting pipes 55. A fifth monitoring unit 59 is provided in the middle of the temperature-gradient chamber 58. The first valve 14 is used to adjust the opening of the exhaust gas bypass, thereby adjusting the exhaust flow rate in the exhaust gas passage, so as to control the middle temperature of the temperature-gradient chamber 58 at a preset value. In this embodiment, the bypass is performed by setting the first valve 14. When exhausting exhaust gas, the flow rate entering the exhaust gas passage is adjusted as needed. A valve can also be set in the exhaust gas passage. The purpose is to maintain a stepped temperature in the temperature storage cylinder 51, and the temperature range of the stepped temperature covers the target temperature required by the engine.

[0030] Working principle: During the operation of engine 7, when the load and power demand of engine 7 are stable, the sixth valve 52 is closed, the premixer 53 and the second injection valve 63 stop moving, the first valve 14 controls the exhaust gas flow, and the exhaust gas temperature is used to statically store the temperature-controlled air in the heat storage cylinder 51. The ECU of engine 7 adjusts the opening of the second valve 22, the third valve 23 and the fourth valve 31 according to the required target temperature, and then monitors the temperature through each monitoring unit and provides feedback to perform multi-level control of the air temperature. When the load or power demand of engine 7 changes, the ECU queries the current MAP to obtain the target temperature A and air-fuel ratio required for the current operating condition. The sixth valve 54 releases air quantitatively into the temperature chamber 58 according to the air-fuel ratio, forcing the air in the temperature chamber 58 into the premixer 53. The fourth monitoring unit 54 fully monitors the pressure of the air before it enters the premixer 53 and the temperature after it is discharged, obtains the temperature reduction of the gas mixture at each temperature, and selects the temperature reduction when the outlet temperature of the premixer 53 is close to the target temperature A. Based on this temperature reduction, the temperature control components of each layer are fed back to regulate the intake air temperature.

[0031] To implement the above-mentioned temperature stratification control airway structure, the present invention also proposes a temperature control method based on any of the above-mentioned intake temperature stratification control airway structures, comprising the following steps: S1: When the engine load or power demand changes, the ECU queries the MAP to obtain the target temperature and air-fuel ratio required for the changed operating conditions. The injection simulation component 5 simulates the target temperature and air-fuel ratio to premix the fuel for the injection conditions and obtains the reduction in the temperature of the mixture. S2: Based on the temperature reduction rate and the target temperature, control each temperature control component to adjust the intake temperature layer by layer so that the temperature of the mixed gas reaches the target temperature; S3: When the engine load and power demand are stable, the injection simulation component 5 is turned off and the required target temperature is maintained.

[0032] Example 2

[0033] Please see Figure 5Unlike Embodiment 1, the intake manifold 12 of this embodiment does not have a first injection valve 62. The engine 7 uses direct injection, and the first injection valve 62 enters the engine 7.

[0034] Example 3

[0035] Please see Figure 6 Unlike Embodiment 1, in this embodiment, the EGR recovery branch includes a fourth valve 31 and an EGR cooler 33 connected in parallel with the fourth valve 31. The inlet or outlet of the EGR cooler 33 is equipped with a fifth valve 32, which has the same effect as the intercooler 21 and its bypass branch. During the waste gas recovery process, the temperature of the high-temperature waste gas is controlled by adjusting the opening of the fourth valve 31 and the fifth valve 32.

[0036] The embodiments described above are merely examples of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention.

Claims

1. An intake temperature stratification control port structure for an ammonia fuel engine, characterized by, include The main airway (1) includes an intake manifold (12), a throttle valve (17), an exhaust manifold (13), and a turbocharger (11). The first temperature control component (2) is located between the intake manifold (12) and the turbocharger (11), and includes an intercooler (21), a bypass branch of the intercooler (21), and a flow control valve; The second temperature control component (3) includes an EGR recovery branch with a valve; The third temperature control component (4) is used to regulate the intake air temperature by electric auxiliary heating; The injection simulation component (5) is used to simulate the injection condition for fuel premixing and obtain the temperature reduction of the mixed gas. Based on the temperature reduction and the target temperature obtained by querying the MAP chart, the temperature control components are controlled to adjust the temperature.

2. The air intake temperature stratification control passage structure for an ammonia fuel engine according to claim 1, characterized by The intercooler (21) and its bypass branch are connected in parallel, and a second valve (22) and a third valve (23) are respectively provided on the intercooler (21) branch and its bypass branch.

3. The air intake temperature stratification control port structure for an ammonia fuel engine according to claim 2, characterized by A first monitoring unit (15) is provided at the junction of the intercooler (21) and the bypass branch of the intercooler (21), and a second monitoring unit (16) is provided at the junction of the junction and the EGR recovery branch. A third temperature control component (4) is provided at the inlet of the intake manifold (12), and a third monitoring unit (18) is also provided at the outlet of the third temperature control component (4).

4. The air intake temperature stratification control port structure for an ammonia fuel engine according to claim 1, characterized by The EGR recovery branch includes a fourth valve (31) and an EGR cooler (33) connected in parallel with the fourth valve (31), wherein a fifth valve (32) is provided at the inlet or outlet of the EGR cooler (33).

5. The air intake temperature stratification control port structure for an ammonia fuel engine according to claim 1, characterized by The injection simulation component (5) includes a premixer (53) and a pair of fourth monitoring units (54) set at the inlet and outlet of the premixer (53) for obtaining the temperature reduction magnitude. The premixer (53) is used to insert the injection valve to simulate gas mixing, and the air inlet of the premixer (53) is connected to the compressed air outlet of the booster (11), and the outlet is connected to the inlet of the third temperature control component (4).

6. The air intake temperature stratification control port structure for an ammonia fuel engine according to claim 5, characterized by The inlet of the booster (11) is also provided with a heat storage cylinder (51), and the exhaust gas of the exhaust manifold (13) passes through the heat storage cylinder (51) to exchange heat and store temperature for the inlet gas of the premixer (53). The inlet of the heat storage cylinder (51) is also provided with a sixth valve (52) for adjusting the flow rate.

7. The air intake temperature stratification control port structure for an ammonia fuel engine according to claim 6, characterized by The storage cylinder (51) has a waste channel at its center and several temperature-gradient chambers (58) are arranged around the exhaust gas channel. The temperature of the temperature-gradient chambers (58) gradually decreases from top to bottom according to the heat dissipation efficiency. The temperature-gradient chambers (58) have branch pipes (56) at both ends. The branch pipes (56) are used to introduce the air from the outlet of the booster (11) into the temperature-gradient chambers (58) and to collect it to the premixer (53).

8. The air intake temperature stratification control port structure for an ammonia fuel engine according to claim 7, characterized by The heat storage cylinder (51) is provided with fins (57) on the outside. The contact area between the fins (57) and the air gradually increases from top to bottom to enhance the heat dissipation efficiency.

9. The air intake temperature stratification control port structure for an ammonia fuel engine according to claim 7, characterized by The exhaust gas passage is provided with connecting pipes (55) at both ends, and a first bypass valve (14) is provided in parallel between the two connecting pipes (55). A fifth monitoring unit (59) is provided in the middle of the temperature chamber (58). The first valve (14) is used to adjust the opening of the exhaust gas bypass, thereby adjusting the waste flow rate in the exhaust gas passage, so as to control the middle temperature of the temperature chamber (58) at a preset value.

10. A temperature control method for the intake temperature stratification control passage structure of an ammonia fuel engine according to any one of claims 1 to 9, characterized by, Includes the following steps: S1: When the engine load or power demand changes, the ECU queries the MAP diagram to obtain the target temperature and air-fuel ratio required for the changed operating conditions. The injection simulation component (5) simulates the target temperature and air-fuel ratio to premix the fuel for the injection conditions and obtains the reduction in the temperature of the mixed gas. S2: Based on the temperature reduction rate and the target temperature, control each temperature control component to adjust the intake air temperature layer by layer so that the temperature of the mixed gas reaches the target temperature; S3: When the engine load and power demand are stable, the injection simulation component (5) is turned off and the required target temperature is maintained.

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