A METHOD FOR TEMPORARY LIMIT CONTROL OF LAMBDA CONNECTED TO AN EXHAUST EMISSION TREATMENT SYSTEM.

Abstract

The invention relates to a method for improving vehicle and engine performance and controlling and limiting NOx (nitrogen oxide) emissions in internal combustion engines during transient conditions, depending on the exhaust treatment system (SCR) conditions, by applying a lambda limiting function.

Description

1 TARIFF TEMPORARY FLAWING OF THE LAMB CONNECTED TO THE EXHAUST PURIFICATION SYSTEM A METHOD THAT ENSURES LIMIT CONTROL Technical Area 5 The invention relates to lambda limitation applied to combustion engines during transient conditions. the function of the exhaust wastewater treatment system (SCR) depends on the vehicle and engine conditions. to improve performance and to control and limit NOx (nitrogen oxide) emissions. It relates to a method that provides control. 10 State of the Art Lambda is calculated by dividing the engine's air-fuel ratio by the stoichiometric air-fuel ratio. It is a parameter that determines whether the air taken into the engine is sufficient or insufficient to burn the fuel. This shows that minimum lambda is used in engines to prevent emissions. A limitation is applied, and the amount of fuel depends on the amount of air available in the engine. This is particularly limited in transient situations such as sudden acceleration. This occurs due to the inability to take in air all at once. In hydrogen internal combustion engines using current technology, NOx (nitrogen oxide) emissions are air-based. The lambda level changes very rapidly depending on the fuel ratio. Instantaneous drop in lambda. Hydrogen-powered engines produce high NOx emissions. This is why hydrogen-powered engines... This is due to the NOx characteristic of the engine related to the lambda sensor, as shown in Figure 1. Therefore, when lambda levels are below 2, a sudden increase in NOx emissions is encountered. Therefore, the engine remains in this state, especially under temporary conditions such as sudden acceleration when the lambda sensor drops. Lambda emissions need to be limited by cutting off the fuel supply. However, this method does not affect emissions. While necessary in terms of safety, it also causes a decrease in engine and vehicle performance. Sudden Turbo lag occurs in engines during transient situations such as acceleration, and thus the engine... It is operating below the target lambda value. 30 In the current state of the art, additional catalysts are used in NOx emission and lambda limiting control. (LNT - lean NOx trap, etc.) is used. However, this method requires an additional component in each engine. This is due to the cost involved. Another method is to use hydrogen spray to remove NOx. 2 Catalysts capable of converting hydrogen are used, but these also do not convert it into fuel. It increases consumption. In another known application of the technique, delayed injection or other methods are used to improve vehicle performance. An afterburner is used. In addition, current technology includes 5 additional hydrogen engines. Solutions exist to reduce NOx emissions, but many are not specifically designed for this purpose. It does not focus on the conflict between NOx emissions and acceleration performance. Hydrogen NOx cycle in catalyst by injection, fuel in late injection and afterburner methods Consumption is increasing. In addition, the hydrogen remaining after late injection is burned in the exhaust. and carries the risk of increasing temperatures. 10 In another instance of the technique, general measures are taken to prevent soot emissions in diesel engines. Diesel lambda limit algorithms require a minimum operating condition based on engine speed and torque. Lambda is being defined. This method is also applied in hydrogen engines. However, The method used leads to a decrease in engine and vehicle acceleration performance. 15 Document US7059114B2, which is included in the known state of the art, describes hydrogen-powered... This discusses how NOx emissions can be reduced in an engine using a lean NOx trap catalyst. Although the document in question seems to solve the NOx problem, This also brings with it problems related to the lean NOx trap (LNT) catalyst, and the document lists 20 Additionally, the addition of extra parts results in an increased cost per vehicle. In another known case of the art, document number JP2007138799A, hydrogen is mentioned. NOx emissions are reduced in the NOx catalyst by injecting hydrogen gas into the engine exhaust. It is mentioned that the reduction is mentioned. Although the document in question states that the NOx catalyst is only 25 Even though it's a method that heats up quickly and increases efficiency, it falls short of providing an increase in engine performance. It remains. Document CN114962040A, included in another known case of the art, concerns injection. It refers to keeping NOx emissions under control by adjusting the timing. (Statement 30) The document explains that it brings about increased efficiency and reduced NOx levels under steady-state conditions. It does not offer any recommendations for variable conditions. 3 Document CN115555044A, included in the other known state of the art, describes the catalyst. By manipulating the materials, the aim is to achieve a more efficient NOx cycle through the use of hydrogen. Although the document in question states that the catalyst in the hydrogen engine provides better NOx conversion... Even though such a method exists, it falls short of providing an increase in engine performance. Therefore, new technologies need to be developed to overcome these disadvantages. is required. Brief Description of the Invention The present invention eliminates the aforementioned disadvantages and the related technical to provide new advantages in the field; in transient situations in internal combustion engines The applied lambda limiting function depends on the exhaust treatment system (SCR) conditions. It relates to a method that provides limit control. The invention allows for monitoring or modifying the lambda limit according to the condition of the exhaust treatment system. This prevents unnecessary performance loss and keeps NOx emissions under control. It ensures that it is obtained. The invented method enables the engine to operate at 20°C under transient conditions such as sudden acceleration, where the lambda level drops. lambda sensor activity can affect engine and vehicle performance when it needs to be limited by cutting off fuel. This helps prevent the decline that has occurred. This invention aims to reduce high NOx emissions in hydrogen engines produced by the instantaneous drop in lambda. To prevent this, a minimum lambda limit is defined in the motor control algorithm. 25 The invention relates the lambda limit to exhaust treatment system parameters (exhaust flow rate, exhaust temperature, SCR (Selective Catalytic Reduction) is achieved by binding the catalyst (ammonia occupancy rate, etc.). by reducing the lambda limit in the regions where the catalyst can convert NOx emissions This improves performance, and where NOx emissions cannot be reversed, lambda is used at 30. By increasing emissions, it helps keep emissions under control. In short, the exhaust system Improved performance where it is efficient, and conversely, NOx where it is inefficient. It helps reduce emissions. 4 The invention describes a method for consuming hydrogen without the need for additional equipment. It provides savings in costs and additional equipment costs. Explanation of the Figures The applications of the invention, briefly summarized above and discussed in more detail below, are as follows: This can be understood by referring to the example applications depicted in the attached drawings. However, the attached that the drawings only depict typical applications of this invention and limit its scope It should be noted that this will not be assumed. Figure 1. A representative flowchart of the method described in the invention. Figure 2. A representative flowchart of the method described in the invention. Figure 3. Variation in NOx emissions due to lambda in a hydrogen engine with current technology. A representative graph illustrating this. Explanation of References in Figures To better understand the invention, the corresponding numbers in the figures are given below: MH. Engine Speed ​​20 MT. Motor Torque LF. Air-Fuel Ratio Limit Function OL. Lambda Limit Fuel Limit Amount (YL) HD. Air Flow Rate 25 F. Function ED. Exhaust Flow Rate ES. Exhaust Temperature DD. Dosing Flow Rate A. SCR Ammonia (NH3) Amount 30 PA. Performance Enhancement. ND. NOx Emission Reduction L. Lambda NOx. Engine exhaust NOx emission sensor. Detailed Description of the Invention Examples of arrangements can be further detailed by referring to the accompanying explanations below. This is how it is described. However, regulations can be formulated in different ways and This should not be interpreted as being limited to the regulations stated here. Instead, this example 5 regulations ensure that this statement is complete and its scope is fully understood by technically qualified individuals. It has been provided for transmission in this manner. The terminology used in this specification is intended only to describe specific example regulations. It is intended to be used for its intended purpose and not to be restrictive. As used herein, 10 The context of the forms "one", "at least", "preferably" and "and / or" varies unless explicitly stated otherwise. It also includes plural forms. The invention relates to lambda limitation applied to combustion engines during transient conditions. The function of the exhaust wastewater treatment system (SCR) depends on the vehicle and engine conditions. 15 to improve performance and to control and limit NOx (nitrogen oxide) emissions. It relates to a method that provides control and includes the following method steps; - Measuring engine speed (MH) with at least one crankshaft sensor, at least one sensor or fuel sensor. The engine torque (MT) is determined by calculation based on the quantity and at least one Calculation of lambda (L) using an oxygen (lambda) sensor or at least one flow sensor 20 Calculation of lambda (L) from the air flow rate measured by, - Creating a NOx model within the function (F) using the measured values ​​and the aforementioned model and / or engine output NOx emission sensor (NOx) and engine output NOx emissions calculating the amount - Exhaust flow rate (ED), exhaust temperature (ES), urea dosing flow rate (DD) and 25 in SCR. Exhaust treatment function (F) depending on the ammonia amount (A) parameters Calculating the amount of NOx emissions that the system (SCR) can convert, - By comparing the two calculated NOx emission levels, the exhaust treatment system (SCR) Reducing the lambda (L) value or the engine when the NOx conversion capacity is high Increasing the lambda (L) value when outlet NOx emissions are high, 30 - Based on the difference between the two calculated NOx emission amounts, what is the lambda (L) limit? The determination of which change will be made according to the NOx model included in the function (F), 6 - The determined amount of lambda (L) change is the air-fuel ratio limit function (LF). within which the lambda (L) limit is calculated based on engine speed (MH) and engine torque (MT). addition, - The lambda limit (OL) output determined by adding stoichiometric air fuel The ratio and air flow rate (HD) and the fuel limit amount (YL) are determined. 5 In this invention, the sensor that enables the measurement of motor torque (MT) is at least one torque sensor, but The application is not limited to this. In the second step of the method described in the invention, the function (F) includes the control unit 10 depends on the engine speed (MH), engine torque (MT) and lambda (L) parameters included. A NOx model is created by performing calculations using maps and tables. The exhaust treatment system (SCR) mentioned in the third step of the invention method The amount of NOx emissions it can convert is given as 15 according to the specified characteristics of the SCR. Calculations are made using maps and tables that depend on the parameters. In the final step of the method described in the invention, the lambda limit (OL) is determined by addition. The air-fuel ratio is determined by multiplying the output by the stoichiometric air-fuel ratio, and the air The fuel limit amount (YL) is calculated by dividing the flow rate (HD) value by the specified air-fuel ratio. determination. The lambda (L) calculated by the final step of the invented method is in the increasing direction. In this case, a reduction in NOx emissions (ND), and an increase in performance if the direction of reduction is towards improvement. (PA) situation occurs. 25 Figure 1 shows which functions the parameters are included in and what outputs those functions have. The data shows which parts are being intervened. Air-fuel ratio limit function (LF). Lambda limit (OL) is determined via a map that depends on engine speed (MH) and engine torque (MT). When calculating, the function (F) takes into account the SCR parameters and engine NOx emissions (sensor 30 Using a model, it makes the decision to increase or decrease the lambda limit (OL) and It calculates how much the lambda (L) needs to be changed. The function (F) and air fuel The final lambda limit (OL) is determined by summing the outputs of the ratio limit function (LF). 7 The value is used to calculate the maximum allowable fuel flow rate based on the air flow rate (HD). It is used. Figure 2 shows the workflow of the invented method. The method responds to the parameters it receives. Depending on the situation, decide whether to decrease or increase the lambda limit (OL) and the difference between them should be 5. It either calculates the necessary difference or makes no changes at all. Figure 3 shows the lambda (L) dependent NOx characteristic of a hydrogen engine. In the figure As shown in Figure 3, when lambda (L) decreases, NOx levels rise suddenly and excessively, and the SCR It is shown that the system can exceed its conversion capacity. With diesel 10 compared, hydrogen NOx especially in regions below 1.9 lambda (L) Its emissions are significantly higher compared to diesel. The invention describes the adequacy of the amount of ammonia (A) that can be used in an exhaust treatment system (SCR), By controlling the exhaust flow rate and SCR catalyst temperature, the lambda limit (OL) is set to 15. It increases or decreases NOx in the exhaust flow (ED) coming from the SCR. there is enough ammonia (A) to convert and at a point in temperature where SCR is efficient. This improves performance by reducing the lambda limit (OL), which is given depending on engine speed and torque. It improves. Critical parameters for lowering the lambda limit (OL) are; SCR temperature. The desired level is 20, which is sufficient to convert the high NOx emissions that will come into the SCR. The amount of ammonia (A) present is the exhaust flow rate (ED), which is the amount of NOx emissions that will be released. It is used in determining this. In summary, the invention leads to improved performance where the exhaust system is efficient, and conversely, to the opposite. Where it is inefficient, it helps reduce NOx emissions. For example, the classic 25 While the algorithm always limits lambda (L) to around 2 depending on speed and torque, the invention is active. When this happens, the lambda limit (OL) drops to values ​​below 2 as far as is allowed, and acceleration occurs. This provides an advantage in performance. Conversely, in the opposite case, lambda (L) is low. By increasing the limit where it is currently limited, it helps to reduce NOx emission values. Any specifications described in this specification (including the attached claims, summary, and drawings) may not be altered unless otherwise stated. Unless explicitly stated otherwise, other alternatives that may serve equivalent or similar purposes can be modified with other properties. That is, unless explicitly stated otherwise, each property can be replaced with a set of equivalent or This is just one example of a similar feature. 8 The above regulations apply only to the technical concept and characteristics of the present invention. The aim is to explain and the purpose of the present invention is to enable experts in the field to understand the present invention. the aim is to enable him to understand the content and apply the existing invention, and the scope of the existing invention. This is not limited to this. Equivalent modifications or those made in accordance with the spirit of the invention. The aim is to include the modifications within the scope of the invention. 5 Industrial Application of the Invention The invention relates to lambda limitation applied to combustion engines during transient conditions. The function of the exhaust wastewater treatment system (SCR) depends on the vehicle and engine conditions. 10 to improve performance and to control and limit NOx (nitrogen oxide) emissions. It relates to a method that provides control and is applicable to industry. The invention is not limited to the above example applications and can be easily developed by a person skilled in the field. It can reveal other different applications of the invention. These are the 15 claims and demands of the invention. It should be considered within the scope of protection.

Claims

9 REQUESTS 1. Lambda limitation applied to internal combustion engines in transient situations. the function of the exhaust wastewater treatment system (SCR) depends on the vehicle and engine conditions.

5. Improving performance and controlling NOx (nitrogen oxide) emissions and to ensure limit control; - Measuring engine speed (MH) with at least one crankshaft sensor, at least one sensor or Engine torque (MT) is determined by calculation based on fuel quantity, and Calculation of lambda (L) with at least one oxygen (lambda) sensor or at least Calculating lambda (L) from air flow measured by a flow sensor, 10 - Creating a NOx model within the function (F) using the measured values ​​and the wording subject model and / or engine outlet NOx emission sensor (NOx) and engine outlet Calculating NOx emission levels. - Exhaust flow rate (ED), exhaust temperature (ES), urea dosing rate (DD) and SCR. Depending on the ammonia amount (A) parameters, the exhaust within the function (F) is 15 Calculating the amount of NOx emissions that the wastewater treatment system (SCR) can convert, - By comparing the two calculated NOx emission levels, the exhaust treatment system... When the (SCR) NOx conversion capacity is high, the lambda (L) value... to reduce or in cases where engine output NOx emissions are high Increasing the lambda (L) value, 20 - Based on the difference between the two calculated NOx emission amounts, what is the lambda (L) limit? according to the NOx model included in the function (F) that will be changed determination, - The determined amount of lambda (L) change is the air-fuel ratio limit function (LF). lambda (L) calculated based on engine speed (MH) and engine torque (MT) 25 to be added to the limit - Stoichiometric air output of lambda limit (OL) determined by addition. Determining the fuel ratio and air flow rate (HD) and fuel limit amount (YL). A method characterized by its inclusion of several steps.

2. Stoichiometric air-fuel ratio of the lambda limit (OL) output determined by addition. The air-fuel ratio is determined by multiplying the air flow rate (HD) value by the specified factor. It is characterized by determining the fuel limit amount (YL) by dividing the fuel ratio by the air-fuel ratio. A method according to Request 1.

3. Claim characterized by the measurement of engine torque (MT) using at least one torque sensor. A method according to point 2.