阅读说明：本技术 用于控制后处理系统中的流量分布的系统和方法 (System and method for controlling flow distribution in an aftertreatment system ) 是由 S·斯里尼瓦桑 于 2018-05-17 设计创作，主要内容包括：用于估计后处理系统中的排气质量流量的方法、装置和系统。实施例包括选择性催化还原(SCR)系统,该系统包括至少一种催化剂、可操作地耦合到SCR系统的差压(dP)传感器、温度传感器和控制器。dP传感器被配置为测量SCR系统上的压差值,确定来自dP传感器的第一输出值和来自温度传感器的第一温度输出值。第一输出值表示SCR系统上的压差值。第一温度输出值表示SCR系统的温度。控制器还被配置为使用来自dP传感器的第一输出值和来自温度传感器的第一温度输出值来估计来自后处理系统的排气质量流量输出。(Methods, apparatus, and systems for estimating exhaust mass flow in an aftertreatment system. Embodiments include a Selective Catalytic Reduction (SCR) system including at least one catalyst, a differential pressure (dP) sensor operably coupled to the SCR system, a temperature sensor, and a controller. The dP sensor is configured to measure a pressure differential across the SCR system, and determine a first output value from the dP sensor and a first temperature output value from the temperature sensor. The first output value represents a pressure differential value across the SCR system. The first temperature output value is indicative of a temperature of the SCR system. The controller is further configured to estimate an exhaust mass flow output from the aftertreatment system using the first output value from the dP sensor and the first temperature output value from the temperature sensor.)

1. An aftertreatment system, comprising:

a Selective Catalytic Reduction (SCR) system comprising at least one catalyst;

a differential pressure (dP) sensor operatively coupled to the SCR system, the dP sensor configured to measure a pressure differential value across the SCR system;

a temperature sensor; and

a controller communicatively coupled with each of the dP sensor and the temperature sensor, the controller configured to:

determining a first output value from the dP sensor, the first output value representing the pressure differential value across the SCR system;

determining a first temperature output value from the temperature sensor, the first temperature output value being representative of a temperature of the SCR system; and

estimating an exhaust mass flow output from the aftertreatment system using the first output value from the dP sensor and the first temperature output value from the temperature sensor.

2. The aftertreatment system of claim 1, wherein estimating the exhaust mass flow output from the aftertreatment system includes calculating a flow coefficient of the SCR system.

3. The aftertreatment system of claim 1, wherein estimating the exhaust mass flow output includes calculating a flow coefficient of the SCR system and a density of exhaust mass flow inside the SCR system.

4. The aftertreatment system of claim 3, wherein the exhaust mass flow output usesTo estimate the time of the arrival of the measured data,

wherein k is implemented asAnd Δ P is a pressure difference.

5. The aftertreatment system of claim 4, wherein the density usesWhere R is the universal gas constant, P_bedIs determined from data obtained on the pressure of the catalyst bed of the catalyst in the SCR, and T_bedIs determined from data obtained from a temperature sensor of the temperature of a catalyst bed of the catalyst in the SCR system.

6. The aftertreatment system of claim 5, wherein the value of k is obtained from a mapping of steady state data at different flow levels.

7. The aftertreatment system of claim 2, further comprising an exhaust mass flow sensor, wherein an exhaust mass flow value is obtained from the exhaust mass flow sensor, and the controller is further configured to:

comparing the estimated exhaust mass flow to the exhaust mass flow value obtained from the exhaust mass flow sensor; and

detecting a potential error in the exhaust mass flow sensor in response to comparing the estimated exhaust mass flow to the exhaust mass flow value obtained from the exhaust mass flow sensor.

8. An aftertreatment system, comprising:

a Selective Catalytic Reduction (SCR) system comprising at least one catalyst;

a particulate filter fluidly coupled to the SCR;

an external particulate filter pressure sensor operatively coupled to the outlet of the particulate filter, the external particulate filter pressure sensor configured to measure a pressure value at the outlet of the particulate filter;

a temperature sensor;

an ambient pressure sensor; and

a controller communicatively coupled with the particulate filter external pressure sensor, the controller configured to:

determining a first output value from a pressure sensor external to the particulate filter, the first output value representing the pressure value at an outlet of the particulate filter;

determining a first temperature output value from the temperature sensor, the first temperature output value being representative of a temperature of the SCR system; and

determining a second output value from the ambient pressure sensor, the second output value representing an ambient pressure value; and

estimating an exhaust mass flow output from the aftertreatment system using the first output value from the external particulate filter pressure sensor, the first temperature output value from the temperature sensor, and the second output value from the ambient pressure sensor.

9. The aftertreatment system of claim 8, wherein estimating the exhaust mass flow output from the aftertreatment system includes calculating a flow coefficient of the SCR system.

10. The aftertreatment system of claim 8, wherein estimating the exhaust mass flow output includes calculating a flow coefficient of the SCR system and a density of exhaust mass flow inside the SCR system.

11. Post-treatment according to claim 10System wherein said exhaust mass flow output usesTo estimate the time of the arrival of the measured data,

wherein k is implemented asAnd Δ P is the pressure differential.

12. The aftertreatment system of claim 11, wherein the density usesWhere R is the universal gas constant, P_bedIs determined from data obtained on the pressure of the catalyst bed of the catalyst in the SCR, and T_bedIs determined from data obtained from a temperature sensor of the temperature of a catalyst bed of the catalyst in the SCR system.

13. The aftertreatment system of claim 12, wherein the value of k is obtained from a mapping of steady state data at different flow levels.

14. The aftertreatment system of claim 9, further comprising an exhaust mass flow sensor, wherein an exhaust mass flow value is obtained from the exhaust mass flow sensor, and the controller is further configured to compare an estimated exhaust mass flow to the exhaust mass flow value obtained from the exhaust mass flow sensor.

15. An aftertreatment system, comprising:

a Selective Catalytic Reduction (SCR) system comprising at least one catalyst;

a plurality of temperature sensors operatively coupled to the SCR system and the controller, wherein the plurality of temperature sensors are configured to measure a plurality of temperature values of the SCR system;

an ambient pressure sensor; and

a controller communicatively coupled with the plurality of temperature sensors and the ambient pressure sensor, the controller configured to:

determining a first output value from a first temperature sensor of the plurality of temperature sensors, the first output value representing one of the plurality of temperature values of the SCR system;

determining a second output value from a second temperature sensor of the plurality of temperature sensors, the second output value representing one of the plurality of temperature values of the SCR system;

determining a third output value from the ambient pressure sensor, the third output value representing an ambient pressure value; and

estimating an exhaust mass flow output from the aftertreatment system using the first output value from the first one of the plurality of temperature sensors, the second output value from the second one of the plurality of temperature sensors, and the third output value from the ambient pressure sensor.

16. The aftertreatment system of claim 15, wherein estimating the exhaust mass flow output from the aftertreatment system includes calculating a flow coefficient of the SCR system.

17. The aftertreatment system of claim 15, wherein estimating the exhaust mass flow output includes calculating a flow coefficient of the SCR system and a density of exhaust mass flow inside the SCR system.

18. The aftertreatment system of claim 17, wherein the exhaust mass flow output usesTo estimate the time of the arrival of the measured data,

wherein k is implemented asAnd Δ P is the pressure differential.

19. The aftertreatment system of claim 18, wherein the density usesWhere R is the universal gas constant, P_bedIs determined from data obtained on the pressure of the catalyst bed of the catalyst in the SCR, and T_bedIs determined from data obtained from a temperature sensor of the temperature of a catalyst bed of the catalyst in the SCR system.

20. The aftertreatment system of claim 16, further comprising an exhaust mass flow sensor, wherein an exhaust mass flow value is obtained from the exhaust mass flow sensor, and the controller is further configured to:

comparing the estimated exhaust mass flow to the exhaust mass flow value obtained from the exhaust mass flow sensor; and

detecting a potential error in the exhaust mass flow sensor in response to comparing the estimated exhaust mass flow to the exhaust mass flow value obtained from the exhaust mass flow sensor.

Technical Field

The present application relates generally to the field of aftertreatment systems for internal combustion engines (internal combustion engines).

Background

For internal combustion engines (such as diesel engines), Nitrogen Oxides (NO)_x) Compounds may be emitted in the exhaust. Stringent emissions requirements, including on-vehicle diagnostic (OBD) requirements dictated by different regulatory bodies, develop robust control algorithms to facilitate the overall system to operate in an optimal manner. To reduce NO_xEmissions, a Selective Catalytic Reduction (SCR) process may be performed to convert NO with the aid of a catalyst and a reductant_xThe compound is converted to a more neutral compound such as diatomic nitrogen, water or carbon dioxide. The catalyst may be included in a catalyst chamber of an exhaust system, such as a catalyst chamber of an exhaust system of a vehicle or generator set. A reductant, such as anhydrous ammonia, aqueous ammonia, Diesel Exhaust Fluid (DEF), or aqueous urea, is typically introduced into the exhaust stream prior to being introduced into the catalyst chamber. In order to introduce the reducing agent into the exhaust gas stream for the SCR process, the SCR system may dose the reducing agent by means of a dosing circuit orOther ways introduce the reducing agent, which the dosing circuit evaporates or injects into the exhaust pipe of the exhaust system upstream of the catalyst chamber. The SCR system may include one or more sensors to monitor conditions within the exhaust system.

SUMMARY

In an embodiment, an aftertreatment system includes an SCR system including at least one catalyst, a differential pressure (dP) sensor operably coupled to the SCR system, a temperature sensor, and a controller. The dP sensor is configured to measure a pressure differential value across the SCR system. The controller is communicatively coupled with each of the dP sensor and the temperature sensor. The controller is configured to determine a first output value from the dP sensor and a first temperature output value from the temperature sensor. The first output value from the dP sensor represents a pressure differential value across the SCR system. The first temperature output value from the temperature sensor is indicative of a temperature of the SCR system. The controller is further configured to estimate an exhaust mass flow output from the aftertreatment system using the first output value from the dP sensor and the first temperature output value from the temperature sensor.

In another embodiment, an aftertreatment system includes an SCR system including at least one catalyst, a particulate filter fluidly coupled to the SCR, an external particulate filter pressure sensor operably coupled to an outlet of the particulate filter, a temperature sensor, an ambient pressure sensor, and a controller communicatively coupled with the external particulate filter pressure sensor. The particulate filter external pressure sensor is configured to measure a pressure value at an outlet of the particulate filter. The controller is configured to determine a first output value from the external particulate filter pressure sensor, a first temperature output value from the temperature sensor, and a second output value from the ambient pressure sensor. A first output value from the pressure sensor outside the particulate filter is indicative of a pressure value at the outlet of the particulate filter. The first temperature output value from the temperature sensor is indicative of a temperature of the SCR system. A second output value from the ambient pressure sensor represents an ambient pressure value. The controller is further configured to estimate an exhaust mass flow output from the aftertreatment system using the first output value from the external particulate filter pressure sensor, the first temperature output value from the temperature sensor, and the second output value from the ambient pressure sensor.

In another embodiment, an aftertreatment system includes an SCR system including at least one catalyst, a plurality of temperature sensors operably coupled to the SCR system, an ambient pressure sensor, and a controller. The plurality of temperature sensors are configured to measure a plurality of temperature values of the SCR system. The controller is communicatively coupled with a plurality of temperature sensors and an ambient pressure sensor. The controller is configured to determine a first output value from a first temperature sensor of the plurality of temperature sensors, a second output value from a second temperature sensor of the plurality of temperature sensors, and a third output value from the ambient pressure sensor. The first output value represents one of a plurality of temperature values of the SCR system. The second output value represents one of a plurality of temperature values of the SCR system. The third output value represents an ambient pressure value. The controller is further configured to estimate an exhaust mass flow output from the aftertreatment system using the first output value from the first of the plurality of temperature sensors, the second output value from the second of the plurality of temperature sensors, and the third output value from the ambient pressure sensor.

In some embodiments, when it is determined that the used output value represents valid data, the controller is further configured to estimate an exhaust mass flow output from the aftertreatment system. Estimating the exhaust mass flow output may include calculating a flow coefficient of the SCR system. Estimating the exhaust mass flow output may include calculating a flow coefficient and a density of the exhaust mass flow within the SCR system. Exhaust mass flow output may be usedWhere k is a flow coefficient implemented as f ((m _ est)), and Δ P is a pressure difference. The density may be estimated using P — P _ bed/(RT _ bed), where R is a common gas constant, P _ bed is determined from data obtained on the pressure of the catalyst bed of the catalyst in the SCR, and T _ bed is determined from the catalyst bed of the catalyst in the SCR systemIs determined from data obtained by the temperature sensor. The value of k may be obtained from a map of steady state data at different flow levels. In some embodiments, the aftertreatment system further comprises an exhaust mass flow sensor, wherein the exhaust mass flow value is obtained from the exhaust mass flow sensor, and the controller is further configured to compare the estimated exhaust mass flow to the exhaust mass flow value obtained from the exhaust mass flow sensor.