Gas ignition engine combustion control system and control method

Abstract

The present invention discloses a combustion control system and method for a gas-ignition engine. The control system includes: a controller for determining the fresh air demand based on the driver's required torque in the current working cycle, and calculating the gas demand based on the equivalent air-fuel ratio, the required excess air coefficient setting value, and the excess air coefficient correction factor; a controller for controlling the throttle valve opening after obtaining the actual air flow to achieve closed-loop control of the fresh air demand; a controller for controlling the gas nozzle to inject gas according to the gas demand after the fresh air demand is reached; and a closed-loop control based on the obtained excess air coefficient measurement value in the exhaust gas in the current working cycle and the required excess air coefficient setting value, outputting the excess air coefficient correction factor. The present invention ensures that the gas and air quantities are equivalently or leanly burned according to the required excess air coefficient setting value, thereby ensuring the economy and stability of the gas-ignition engine.

Description

Technical Field

[0001] The present invention relates to the field of automobile technology, and in particular to a gas ignition engine combustion control system and a control method. Background Art

[0002] Gas-ignition engines, such as natural gas engines, offer similar power performance to diesel engines of the same displacement, with significant environmental advantages, making them more resilient to increasingly stringent emissions regulations. Recognizing this trend, leading domestic and international engine manufacturers have launched a number of gas-ignition engine models. Lean-burn combustion significantly reduces fuel consumption, but is limited by the lean-burn threshold, making gas-ignition engines unstable. Stoichiometric combustion ensures smooth combustion but requires a higher gas volume. Due to temperature and other factors, both lean-burn and stoichiometric combustion can cause fresh air and fuel volume requirements to fall short of actual needs, rendering gas-ignition engines unstable and unable to achieve economical combustion. Summary of the Invention

[0003] The present invention provides a gas ignition engine combustion control system and control method, which can ensure that the gas and air quantities are subjected to equivalent / lean combustion according to the required excess air coefficient setting value, thereby ensuring the economy and stability of the gas ignition engine.

[0004] According to one aspect of the present invention, a gas ignition engine combustion control system is provided, comprising:

[0005] Gas nozzle, air flow sensor, throttle, air-gas mixer, original line oxygen concentration sensor, engine and controller;

[0006] A gas nozzle is provided at the inlet of the gas pipeline; an air flow sensor and a throttle are provided on the air pipeline, a first end of the throttle is connected to the air flow sensor; a second end of the throttle is connected to a first end of an air-gas mixer via the air pipeline, and a second end of the air-gas mixer is connected to the gas pipeline; a third end of the air-gas mixer is connected to a first end of the engine, and an exhaust gas oxygen concentration sensor is provided on the exhaust gas pipeline at the second end of the engine; the air-gas mixer is used to mix air and gas;

[0007] The controller is electrically connected to the gas nozzle, the air flow sensor, the throttle valve and the original exhaust line oxygen concentration sensor respectively;

[0008] The controller is used to determine the fresh air demand according to the engine torque in the current working cycle, and calculate the gas demand according to the equivalent air-fuel ratio, the required excess air coefficient setting value and the excess air coefficient correction coefficient;

[0009] The air flow sensor is used to detect the actual air flow; the controller is used to obtain the actual air flow and then control the throttle valve to adjust the valve opening according to the actual air flow, so that the actual air flow meets the fresh air demand, realizing closed-loop control of the air flow;

[0010] The controller is also used to control the gas nozzle to spray gas according to the gas demand after determining that the actual air flow reaches the fresh air demand;

[0011] The original exhaust line oxygen concentration sensor is used to detect the measured value of the excess air coefficient in the exhaust gas in the current working cycle. The controller is also used to determine the excess air coefficient correction coefficient in the next working cycle based on the obtained measured value of the excess air coefficient in the current working cycle, thereby realizing closed-loop control of the gas volume.

[0012] Optionally, if the fuel gas is natural gas, the required excess air coefficient setting value is 1.

[0013] Optionally, if the fuel gas is hydrogen, the required excess air coefficient setting value is 2.5.

[0014] Optionally, the controller is used to determine the excess air coefficient correction coefficient based on the ratio between the excess air coefficient measurement value in the exhaust gas in the current working cycle and the required excess air coefficient set value.

[0015] Optionally, the controller is used to determine a first excess air coefficient correction coefficient based on the ratio between the excess air coefficient measured value in the exhaust gas in the current working cycle and the required excess air coefficient set value when the excess air coefficient measured value in the current working cycle is greater than the required excess air coefficient set value, so as to increase the amount of gas injected by the gas nozzle in the next working cycle.

[0016] Optionally, the controller is used to determine a second excess air coefficient correction coefficient based on the ratio between the excess air coefficient measured value in the exhaust gas in the current working cycle and the required excess air coefficient set value when the excess air coefficient measured value in the current working cycle is equal to the required excess air coefficient set value, so as to keep the amount of gas injected by the gas nozzle in the next working cycle consistent with the amount of gas injected by the gas nozzle in the current working cycle.

[0017] Optionally, the controller is used to determine a third excess air coefficient correction coefficient based on the ratio between the excess air coefficient measured value in the exhaust gas in the current working cycle and the required excess air coefficient set value when the excess air coefficient measured value in the current working cycle is less than the required excess air coefficient set value, so as to reduce the amount of gas injected by the gas nozzle in the next working cycle.

[0018] Optionally, the gas ignition engine combustion control system may also include:

[0019] Three-way catalytic converter, the three-way catalytic converter is arranged between the original exhaust line oxygen concentration sensor and the exhaust gas outlet, and the three-way catalytic converter is used to purify the exhaust gas.

[0020] According to another aspect of the present invention, a gas ignition engine combustion control method is provided, wherein the gas ignition engine combustion control system includes: a gas nozzle, an air flow sensor, a throttle, an air-gas mixer, a raw line oxygen concentration sensor, and a controller;

[0021] A gas nozzle is provided at the inlet of the gas pipeline; an air flow sensor and a throttle are provided on the air pipeline, a first end of the throttle is connected to the air flow sensor; an air pipeline at a second end of the throttle is connected to a first end of an air-gas mixer, a second end of the air-gas mixer is connected to the gas pipeline; a third end of the air-gas mixer is connected to a first end of the engine, and an exhaust line oxygen concentration sensor is provided on an exhaust pipe at a second end of the engine; the air-gas mixer is used to mix air and gas;

[0022] The controller is electrically connected to the gas nozzle, air flow sensor, throttle and original line oxygen concentration sensor respectively; the air flow sensor is used to detect the actual air flow; the original line oxygen concentration sensor is used to detect the excess air coefficient measurement value in the exhaust gas in the current working cycle.

[0023] Gas ignition engine combustion control methods include:

[0024] In the current working cycle, the controller determines the fresh air demand based on the engine torque, and calculates the gas demand based on the equivalent air-fuel ratio, the required excess air coefficient setting value and the excess air coefficient correction coefficient;

[0025] After obtaining the actual air flow, the controller controls the throttle valve to adjust the valve opening according to the actual air flow, so that the actual air flow meets the fresh air demand, realizing closed-loop control of the air flow;

[0026] After the controller determines that the actual air flow reaches the fresh air demand, it controls the gas nozzle to spray gas according to the gas demand;

[0027] The controller determines the excess air coefficient correction coefficient in the next working cycle based on the excess air coefficient measurement value obtained in the current working cycle, thereby realizing closed-loop control of the gas quantity.

[0028] Optionally, the controller determines the excess air coefficient correction coefficient in the next working cycle based on the acquired excess air coefficient measurement value in the current working cycle, including:

[0029] The controller determines the excess air coefficient correction coefficient based on the ratio between the measured value of the excess air coefficient in the exhaust gas in the current working cycle and the required excess air coefficient set value.

[0030] The technical solution of the embodiment of the present invention is achieved by setting a gas nozzle, an air flow sensor, a throttle, an air-gas mixer, an original line oxygen concentration sensor, an engine and a controller; the controller is used to determine the fresh air demand according to the driver's required torque in the current working cycle, and calculate the gas demand according to the equivalent air-fuel ratio, the required excess air coefficient setting value, and the excess air coefficient correction coefficient; the air flow sensor is used to detect the actual air flow; the controller is used to control the throttle to adjust the valve opening according to the actual air flow after obtaining the actual air flow, so that the actual air flow reaches the fresh air demand, thereby realizing closed-loop control of the air flow; the controller is also used to control the gas nozzle to spray gas according to the gas demand after determining that the actual air flow reaches the fresh air demand; the original line oxygen concentration sensor is used to detect the excess air coefficient measurement value in the exhaust gas in the current working cycle, and the controller is also used to determine the excess air coefficient correction coefficient in the next working cycle based on the excess air coefficient measurement value obtained in the current working cycle, thereby realizing closed-loop control of the gas quantity. The present invention can detect the actual air flow in real time by setting an air flow sensor and transmit the actual air flow value to the controller. The controller controls and adjusts the valve opening of the throttle according to the obtained actual air flow value to ensure that the actual air flow reaches the fresh air demand value, and corrects the gas demand by the excess air coefficient correction coefficient, so as to ensure that the gas and air quantities are equivalently or leanly burned according to the required excess air coefficient setting value, thereby ensuring the economy and stability of the gas ignition engine.

[0031] It should be understood that the content described in this section is not intended to identify the key or important features of the embodiments of the present invention, nor is it intended to limit the scope of the present invention. Other features of the present invention will become readily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0033] Figure 1 This is a schematic structural diagram of a gas ignition engine combustion control system provided in Example 1 of the present invention;

[0034] Figure 2 This is a flow chart of a gas ignition engine combustion control method provided in the second embodiment of the present invention. DETAILED DESCRIPTION

[0035] In order to enable those skilled in the art to better understand the solutions of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of the present invention.

[0036] It should be noted that the terms "first", "second", etc. in the description and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0037] Example 1

[0038] The embodiment of the present invention provides a gas ignition engine combustion control system. Figure 1 This is a schematic diagram of a gas ignition engine combustion control system provided by the first embodiment of the present invention, with reference to Figure 1 The gas ignition engine combustion control system includes: a gas nozzle 10, an air flow sensor 20, a throttle valve 30, an air-gas mixer 40, an exhaust gas oxygen concentration sensor 50, an engine 60 and a controller; the gas nozzle 10 is provided at the inlet of the gas pipeline; the air flow sensor 20 and the throttle valve 30 are provided on the air pipeline, and the first end of the throttle valve 30 is connected to the air flow sensor 20; the second end of the throttle valve 30 is connected to the first end of the air-gas mixer 40 through the air pipeline, and the second end of the air-gas mixer 40 is connected to the gas pipeline; the third end of the air-gas mixer 40 is connected to the first end of the engine 60, and the exhaust gas pipeline of the second end of the engine 60 is provided with an exhaust gas oxygen concentration sensor 50; the air-gas mixer 40 is used to mix air and gas; the controller is electrically connected to the gas nozzle 10, the air flow sensor 20, the throttle valve 30 and the exhaust gas oxygen concentration sensor 50 respectively.

[0039] The controller is used to determine the fresh air demand according to the driver's required torque in the current working cycle, and calculate the gas demand according to the equivalent air-fuel ratio, the required excess air coefficient setting value and the excess air coefficient correction coefficient; the air flow sensor 20 is used to detect the actual air flow; the controller is used to control the throttle 30 to adjust the valve opening according to the actual air flow after obtaining the actual air flow, so that the actual air flow reaches the fresh air demand, thereby realizing closed-loop control of the air flow; the controller is also used to control the gas nozzle 10 to spray gas according to the gas demand after determining that the actual air flow reaches the fresh air demand; the original line oxygen concentration sensor 50 is used to detect the excess air coefficient measurement value in the exhaust gas in the current working cycle, and the controller is also used to determine the excess air coefficient correction coefficient in the next working cycle based on the obtained excess air coefficient measurement value in the current working cycle, thereby realizing closed-loop control of the gas quantity.

[0040] The controller is not in Figure 1 As shown, the fuel gas can be natural gas or hydrogen. In the current operating cycle, the controller determines the driver's requested torque upon detecting the pedal opening depressed by the driver, and determines the fresh air demand based on the driver's requested torque. The controller then controls the valve opening of the throttle valve 30 based on the actual air flow detected by the air flow sensor 20. For example, if the detected actual air flow is less than the fresh air demand, the controller increases the valve opening of the throttle valve 30. If the detected actual air flow is equal to the fresh air demand, the controller maintains the valve opening of the throttle valve 30 to ensure that the actual air flow reaches the fresh air demand. The air flow sensor 20 can detect the actual air flow in real time. The controller uses the actual air flow value obtained to control and adjust the valve opening of the throttle valve 30 to ensure that the actual air flow reaches the fresh air demand, thus achieving closed-loop air flow control to meet the driver's driving needs.

[0041] Specifically, the controller calculates the gas demand based on the equivalent air-fuel ratio, the required excess air coefficient setting value, the excess air coefficient correction coefficient and the fresh air demand. For example, the required excess air coefficient setting value can be 1 or 2.5. When the required excess air coefficient setting value is 1, it can be determined as equivalent combustion. Under the condition of equivalent combustion, the fresh air demand and the gas demand are required to be burned in a 1:1 ratio; when the hydrangea excess air control coefficient setting value is 2.5, it can be determined as lean combustion. Under the condition of lean combustion, the fresh air demand and the gas demand are required to be burned in a 2.5:1 ratio; the gas ignition engine equivalent combustion or lean combustion control can be achieved by setting the required excess air control coefficient setting value. During the initial working process, the excess air coefficient correction coefficient can be zero, and combustion is carried out according to the ratio of fresh air demand and gas demand in equivalent combustion or lean combustion. However, under the conditions of equivalent combustion and lean combustion during the working process, due to the influence of temperature and other conditions, there may be a situation where the gas demand is slightly lean or slightly rich. Therefore, the excess air coefficient correction coefficient is required for correction. The excess air coefficient correction coefficient is used to correct the gas volume, thereby realizing closed-loop control of the gas volume, which can ensure that the gas volume and air volume are burned stoichiometrically or leanly according to the required excess air coefficient setting value, thereby ensuring the economy and stability of the gas ignition engine.

[0042] The excess air coefficient measurement value reflects the air measurement value in the exhaust gas after the combustion of air and gas. The controller determines whether the gas volume in the current working cycle is slightly rich or slightly lean based on the excess air coefficient measurement value obtained in the current working cycle, and thus determines the excess air coefficient correction coefficient in the next working cycle based on the excess air coefficient measurement value. For example, if, in the case of equivalent combustion, the controller detects that the excess air coefficient measurement value in the exhaust gas in the current working cycle is greater than the required excess air control coefficient setting value, it means that the gas volume in the current working cycle is slightly lean, and the gas demand is increased in the next working cycle. The gas demand that needs to be increased is the excess air coefficient correction coefficient. In the next working cycle, the controller controls the gas nozzle to spray gas according to the gas demand calculated based on the equivalent air-fuel ratio, the required excess air coefficient setting value, the excess air coefficient correction coefficient, and the fresh air demand.

[0043] The technical solution of the embodiment of the present invention is provided by setting a gas nozzle 10, an air flow sensor 20, a throttle valve 30, an air-gas mixer 40, an original line oxygen concentration sensor 50, an engine 60 and a controller; the controller is used to determine the fresh air demand according to the driver's required torque in the current working cycle, and calculate the gas demand according to the equivalent air-fuel ratio, the required excess air coefficient setting value, and the excess air coefficient correction coefficient; the air flow sensor 20 is used to detect the actual air flow; the controller is used to control the throttle valve 30 to adjust the valve opening according to the actual air flow after obtaining the actual air flow, so that the actual air flow reaches the fresh air demand; the controller is also used to control the gas nozzle 10 to spray gas according to the gas demand after determining that the actual air flow reaches the fresh air demand; the original line oxygen concentration sensor 50 is used to detect the excess air coefficient measurement value in the exhaust gas in the current working cycle, and the controller is also used to determine the excess air coefficient correction coefficient in the next working cycle based on the excess air coefficient measurement value obtained in the current working cycle. The present invention utilizes an air flow sensor 20 to detect actual air flow in real time and transmit this value to a controller. The controller uses this value to adjust the opening of the throttle valve 30 to ensure that the actual air flow meets the required fresh air value. Furthermore, the controller uses the excess air coefficient correction factor to correct the required gas flow. This ensures that the gas and air flows are burned in a stoichiometric or lean manner according to the required excess air coefficient setting, thus ensuring the fuel economy and stability of the gas-ignition engine.

[0044] Optionally, if the fuel gas is natural gas, the required excess air coefficient setting value is 1.

[0045] If the gas is natural gas and the required excess air coefficient is set to 2.5, lean burn is adopted, but the natural gas easily reaches the lean burn boundary, making the gas-ignition engine unstable. Therefore, if the gas is natural gas and the required excess air coefficient is set to 1, stoichiometric combustion is adopted to ensure the stability of the gas-ignition engine. By setting the required excess air coefficient setting, stoichiometric or lean burn control of the gas-ignition engine can be achieved, enabling flexible testing of the gas-ignition engine under different gas conditions.

[0046] Optionally, if the fuel gas is hydrogen, the required excess air coefficient setting value is 2.5.

[0047] Among them, if the fuel gas is hydrogen, if the demand excess air coefficient is set to 1, stoichiometric combustion is adopted, which can ensure the stability of the gas-ignition engine, but will increase the gas demand. If the demand excess air coefficient is set to 2.5, lean burn is adopted. The boundary of hydrogen lean burn is very high, which will not make the gas-ignition engine unstable and can also save gas. By setting the demand excess air control coefficient setting value, stoichiometric or lean burn control of the gas-ignition engine can be achieved, thus realizing flexible experimentation of the gas-ignition engine under different fuel conditions.

[0048] Optionally, the controller is used to determine the excess air coefficient correction coefficient based on the ratio between the excess air coefficient measurement value in the exhaust gas in the current working cycle and the required excess air coefficient set value.

[0049] For example, if the ratio between the excess air coefficient measurement value and the required excess air coefficient setting value is greater than 1, it means that there is excess air and the gas is slightly lean, so the gas demand is increased in the next working cycle, and the gas demand that needs to be increased is the excess air coefficient correction coefficient; if the ratio between the excess air coefficient measurement value and the required excess air coefficient setting value is less than 1, it means that the gas is slightly rich, so the gas demand is reduced in the next working cycle, and the gas demand that needs to be reduced is the excess air coefficient correction coefficient; if the ratio between the excess air coefficient measurement value and the required excess air coefficient setting value is 1, then the gas demand in the current working cycle is maintained in the next working cycle, and the excess air coefficient correction coefficient is zero; in the next working cycle, the controller controls the gas nozzle to spray gas according to the gas demand calculated according to the equivalent air-fuel ratio, the required excess air coefficient setting value, the excess air coefficient correction coefficient and the fresh air demand.

[0050] Optionally, the controller is used to determine a first excess air coefficient correction coefficient based on the ratio between the excess air coefficient measurement value and the required excess air coefficient setting value when the excess air coefficient measurement value in the current working cycle is greater than the required excess air coefficient setting value, so as to increase the amount of gas injected by the gas nozzle in the next working cycle.

[0051] Among them, when the measured value of the excess air coefficient in the current working cycle is greater than the set value of the required excess air coefficient, it means that the gas in the current working cycle is slightly lean, and the ratio between the measured value of the excess air coefficient and the set value of the required excess air coefficient is greater than 1, there is surplus air, and the gas is slightly lean, then the gas demand is increased in the next working cycle, and the gas demand that needs to be increased is the first excess air coefficient correction coefficient. In the next working cycle, the controller calculates the gas demand based on the equivalent air-fuel ratio, the set value of the required excess air coefficient, the first excess air coefficient correction coefficient and the fresh air demand, and can increase the amount of gas injected by the gas nozzle in the next working cycle.

[0052] Optionally, the controller is used to determine a second excess air coefficient correction coefficient based on the ratio between the excess air coefficient measurement value and the required excess air coefficient setting value when the excess air coefficient measurement value in the current working cycle is equal to the required excess air coefficient setting value, so as to keep the amount of gas injected by the gas nozzle in the next working cycle consistent with the amount of gas injected by the gas nozzle in the current working cycle.

[0053] Among them, when the excess air coefficient measurement value in the current working cycle is equal to the required excess air coefficient setting value, the ratio between the excess air coefficient measurement value and the required excess air coefficient setting value is 1, then the gas demand in the current working cycle is maintained in the next working cycle, and the second excess air coefficient correction coefficient is zero. In the next working cycle, the controller calculates the gas demand based on the equivalent air-fuel ratio, the required excess air coefficient setting value, the second excess air coefficient correction coefficient and the fresh air demand, so as to keep the gas amount injected by the gas nozzle in the next working cycle consistent with the gas amount injected by the gas nozzle in the current working cycle.

[0054] Optionally, the controller is used to determine a third excess air coefficient correction coefficient based on the ratio between the excess air coefficient measurement value and the required excess air coefficient setting value when the excess air coefficient measurement value in the current working cycle is less than the required excess air coefficient setting value, so as to reduce the amount of gas injected by the gas nozzle in the next working cycle.

[0055] Among them, when the measured value of the excess air coefficient in the current working cycle is less than the set value of the required excess air coefficient, the ratio between the measured value of the excess air coefficient and the set value of the required excess air coefficient is less than 1, which means that the gas amount in the current working cycle is slightly rich, then the gas demand is reduced in the next working cycle, and the gas demand that needs to be reduced is the excess air coefficient correction coefficient; in the next working cycle, the controller calculates the gas demand based on the equivalent air-fuel ratio, the set value of the required excess air coefficient, the third excess air coefficient correction coefficient and the fresh air demand, and can reduce the gas amount injected by the gas nozzle in the next working cycle.

[0056] Optional, reference Figure 1 The gas ignition engine combustion control system further includes: a three-way catalytic converter 70, which is arranged between the original line oxygen concentration sensor 50 and the exhaust gas outlet, and is used to purify the exhaust gas.

[0057] The three-way catalytic converter 70 can be used to purify tail exhaust nitrogen oxide (NOX) exhaust gas to meet VI emission regulations.

[0058] Example 2

[0059] The embodiment of the present invention provides a gas ignition engine combustion control method based on the above embodiment. The gas ignition engine combustion control system includes: a gas nozzle, an air flow sensor, a throttle, an air-gas mixer, a raw line oxygen concentration sensor and a controller;

[0060] A gas nozzle is provided at the inlet of the gas pipeline; an air flow sensor and a throttle are provided on the air pipeline, a first end of the throttle is connected to the air flow sensor; a second end of the throttle is connected to a first end of an air-gas mixer via the air pipeline, and a second end of the air-gas mixer is connected to the gas pipeline; a third end of the air-gas mixer is connected to a first end of the engine, and an exhaust gas oxygen concentration sensor is provided on the exhaust gas pipeline at the second end of the engine; the air-gas mixer is used to mix air and gas;

[0061] The controller is electrically connected to the gas nozzle, air flow sensor, throttle valve and original line oxygen concentration sensor respectively; the air flow sensor is used to detect the actual air flow; the original line oxygen concentration sensor is used to detect the excess air coefficient measurement value in the exhaust gas in the current working cycle;

[0062] Figure 2 This is a flow chart of a gas ignition engine combustion control method provided by the second embodiment of the present invention, with reference to Figure 2 , a gas ignition engine combustion control method includes:

[0063] Step 110 : In the current working cycle, the controller determines the fresh air demand according to the driver's demand torque, and calculates the fuel gas demand according to the equivalent air-fuel ratio, the required excess air coefficient setting value, and the excess air coefficient correction coefficient.

[0064] Step 120: After obtaining the actual air flow, the controller controls the throttle valve to adjust the valve opening according to the actual air flow so that the actual air flow reaches the fresh air demand, thereby realizing closed-loop control of the air flow.

[0065] Step 130: After the controller determines that the actual air flow reaches the fresh air demand, it controls the gas nozzle to spray gas according to the gas demand;

[0066] Step 140: The controller determines the excess air coefficient correction coefficient in the next working cycle based on the excess air coefficient measurement value obtained in the current working cycle, thereby achieving closed-loop control of the gas quantity.

[0067] The combustion control method for a gas-ignition engine provided by an embodiment of the present invention ensures that the gas and air quantities are stoichiometrically or leanly burned according to the required excess air coefficient setting, thereby ensuring the economy and stability of the gas-ignition engine. Furthermore, stoichiometric or lean-burn control of the gas-ignition engine can be achieved by simply changing the excess air coefficient setting.

[0068] Optionally, the controller determines the excess air coefficient correction coefficient in the next working cycle based on the excess air coefficient measurement value obtained in the current working cycle, including: the controller determines the excess air coefficient correction coefficient based on the ratio between the excess air coefficient measurement value in the exhaust gas in the current working cycle and the required excess air coefficient setting value.

[0069] The gas ignition engine combustion control method provided by the technical solution of the embodiment of the present invention and the gas ignition engine combustion control system provided by the embodiment of the present invention belong to the same inventive concept and have the same beneficial effects. For technical details not detailed in this embodiment, please refer to the gas ignition engine combustion control system described in any embodiment of the present invention.

[0070] It should be understood that the various forms of the processes shown above can be used to reorder, add, or delete steps. For example, the steps described in the present invention can be performed in parallel, sequentially, or in a different order, as long as the desired results of the technical solution of the present invention can be achieved. This is not limited herein.

[0071] The above specific embodiments do not limit the scope of protection of the present invention. Those skilled in the art will appreciate that various modifications, combinations, sub-combinations, and substitutions may be made based on design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention are intended to be included within the scope of protection of the present invention.

Claims

1. A gas ignition engine combustion control system, characterized in that: include: Gas nozzle, air flow sensor, throttle, air-gas mixer, original line oxygen concentration sensor, engine and controller; The gas nozzle is provided at the inlet of the gas pipeline; the air flow sensor and the throttle are provided on the air pipeline, the first end of the throttle is connected to the air flow sensor; the second end of the throttle is connected to the first end of the air-gas mixer via the air pipeline, and the second end of the air-gas mixer is connected to the gas pipeline; the third end of the air-gas mixer is connected to the first end of the engine, and the exhaust pipe at the second end of the engine is provided with an exhaust line oxygen concentration sensor; the air-gas mixer is used to mix air and gas; The controller is electrically connected to the gas nozzle, the air flow sensor, the throttle valve and the raw line oxygen concentration sensor respectively; The controller is used to determine the fresh air demand according to the driver's required torque in the current working cycle, and calculate the gas demand according to the equivalent air-fuel ratio, the required excess air coefficient setting value and the excess air coefficient correction coefficient; the air flow sensor is used to detect the actual air flow; The controller is used to obtain the actual air flow and then control the throttle valve to adjust the valve opening according to the actual air flow, so that the actual air flow reaches the fresh air demand, thereby realizing closed-loop control of the air flow; The controller is further configured to control the gas nozzle to spray gas according to the gas demand after determining that the actual air flow reaches the fresh air demand; The original line oxygen concentration sensor is used to detect the measured value of the excess air coefficient in the exhaust gas in the current working cycle. The controller is also used to determine the excess air coefficient correction coefficient in the next working cycle based on the obtained measured value of the excess air coefficient in the current working cycle, so as to realize closed-loop control of the gas volume.

2. The gas ignition engine combustion control system according to claim 1, characterized in that: If the fuel gas is natural gas, the required excess air coefficient setting value is 1.

3. The gas ignition engine combustion control system according to claim 1, characterized in that: If the fuel gas is hydrogen, the required excess air coefficient setting value is 2.

5.

4. The gas ignition engine combustion control system according to claim 1, characterized in that: The controller is used to determine the excess air coefficient correction coefficient based on the ratio between the excess air coefficient measurement value in the exhaust gas in the current working cycle and the required excess air coefficient set value.

5. The gas ignition engine combustion control system according to claim 4, characterized in that: The controller is used to determine a first excess air coefficient correction coefficient based on the ratio between the excess air coefficient measurement value in the exhaust gas in the current working cycle and the required excess air coefficient setting value when the excess air coefficient measurement value in the current working cycle is greater than the required excess air coefficient setting value, so as to increase the amount of gas injected by the gas nozzle in the next working cycle.

6. The gas ignition engine combustion control system according to claim 4, characterized in that: The controller is used to determine a second excess air coefficient correction coefficient based on the ratio between the excess air coefficient measurement value in the exhaust gas in the current working cycle and the required excess air coefficient setting value when the excess air coefficient measurement value in the current working cycle is equal to the required excess air coefficient setting value, so as to keep the amount of gas injected by the gas nozzle in the next working cycle consistent with the amount of gas injected by the gas nozzle in the current working cycle.

7. The gas ignition engine combustion control system according to claim 4, characterized in that: The controller is used to determine a third excess air coefficient correction coefficient based on the ratio between the excess air coefficient measurement value in the exhaust gas in the current working cycle and the required excess air coefficient setting value when the excess air coefficient measurement value in the current working cycle is less than the required excess air coefficient setting value, so as to reduce the amount of gas injected by the gas nozzle in the next working cycle.

8. The gas ignition engine combustion control system according to claim 1, characterized in that: Also includes: A three-way catalytic converter is arranged between the original line oxygen concentration sensor and the exhaust gas outlet, and is used to purify the exhaust gas.

9. A method for controlling combustion of a gas ignition engine, characterized in that: The gas ignition engine combustion control system includes: gas nozzle, air flow sensor, throttle, air-gas mixer, original line oxygen concentration sensor and controller; The gas nozzle is provided at the inlet of the gas pipeline; the air flow sensor and the throttle are provided on the air pipeline, the first end of the throttle is connected to the air flow sensor; the air pipeline at the second end of the throttle is connected to the first end of the air-gas mixer, and the second end of the air-gas mixer is connected to the gas pipeline; the third end of the air-gas mixer is connected to the first end of the engine, and an exhaust line oxygen concentration sensor is provided on the exhaust pipeline at the second end of the engine; the air-gas mixer is used to mix air and gas; The controller is electrically connected to the gas nozzle, the air flow sensor, the throttle valve and the original line oxygen concentration sensor respectively; the air flow sensor is used to detect the actual air flow; the original line oxygen concentration sensor is used to detect the excess air coefficient measurement value in the exhaust gas in the current working cycle; Gas ignition engine combustion control methods include: The controller determines the fresh air requirement according to the driver's required torque in the current working cycle, and calculates the gas requirement according to the equivalent air-fuel ratio, the required excess air coefficient setting value and the excess air coefficient correction coefficient; After obtaining the actual air flow, the controller controls the throttle valve to adjust the valve opening according to the actual air flow, so that the actual air flow reaches the fresh air demand, thereby realizing closed-loop control of the air flow; After the controller determines that the actual air flow reaches the fresh air demand, it controls the gas nozzle to spray gas according to the gas demand; The controller determines the excess air coefficient correction coefficient in the next working cycle based on the excess air coefficient measurement value obtained in the current working cycle, thereby realizing closed-loop control of the gas amount.

10. The gas ignition engine combustion control method according to claim 9, characterized in that: The controller determines, based on the acquired excess air coefficient measurement value in the current working cycle, an excess air coefficient correction coefficient in the next working cycle, including: The controller determines an excess air coefficient correction coefficient according to a ratio between a measured value of the excess air coefficient in the exhaust gas in a current working cycle and the required excess air coefficient set value.

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