Sensor and combustion system comprising same

Abstract

The application discloses a sensor and a combustion system comprising the same. The sensor according to the embodiment of the application comprises a reference oxygen chamber, a first chamber, a second chamber, a third chamber, a nitrogen oxide measuring unit and a carbon hydrogen measuring unit. The first chamber is connected with the outside through a first diffusion channel. The second chamber is connected with the first chamber through a second diffusion channel. The third chamber is connected with the second chamber through a third diffusion channel. The nitrogen oxide measuring unit is used for measuring the concentration of nitrogen oxide. The carbon hydrogen measuring unit comprises a carbon hydrogen electrode, a reference electrode arranged in the reference oxygen chamber and a carbon hydrogen measuring unit. The carbon hydrogen measuring unit obtains the carbon hydrogen concentration according to the voltage difference between the carbon hydrogen electrode and the reference electrode. The sensor and the combustion system comprising the same according to the embodiment of the application are additionally designed with the carbon hydrogen electrode to measure the carbon hydrogen concentration, and integrate the nitrogen oxide measurement and the carbon hydrogen measurement.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of sensors, in particular to a sensor and a combustion system comprising the same. BACKGROUND

[0002] With the development of economic society, the number of motor vehicles is also increasing year by year, but the harmful ingredients contained in the exhaust gas emitted by motor vehicles will cause serious pollution to the atmosphere, such as carbon monoxide, nitrogen oxides (nitric oxide and nitrogen dioxide, collectively referred to as NO x ), sulfides, fine particulate matter, etc. These harmful ingredients greatly affect the environment and the survival of animals and plants.

[0003] In the prior art, sensors are of great significance to motor vehicle exhaust treatment systems. However, the current sensors are often special-purpose sensors, which can only realize the detection of a certain gas, and the application range is narrow, and cannot meet the detection needs of multiple gases.

[0004] Therefore, it is hoped that there will be a new sensor and a combustion system comprising the same. SUMMARY

[0005] In view of the above problems, the purpose of the present application is to provide a sensor and a combustion system comprising the same, so as to measure the concentration of carbon and hydrogen by additionally designing a carbon and hydrogen electrode.

[0006] According to an aspect of the present application, a sensor is provided, comprising: a reference oxygen chamber; a first chamber communicating with the outside through a first diffusion channel; a second chamber communicating with the first chamber through a second diffusion channel; a third chamber communicating with the second chamber through a third diffusion channel; a nitrogen oxide measuring unit for measuring the concentration of nitrogen oxides; and a carbon and hydrogen measuring unit for measuring the concentration of carbon and hydrogen, wherein the carbon and hydrogen measuring unit comprises: a carbon and hydrogen electrode; a reference electrode arranged in the reference oxygen chamber; and the carbon and hydrogen measuring unit obtains the concentration of carbon and hydrogen according to the voltage difference between the carbon and hydrogen electrode and the reference electrode.

[0007] Optionally, the sensor further comprises: a first electrode arranged in the first chamber; an upper electrode and a lower electrode arranged oppositely in the second chamber; wherein the first pump unit comprises the outer electrode and the first electrode; the second pump unit comprises the outer electrode and the upper electrode or the lower electrode; the third pump unit comprises the outer electrode and the third electrode; the first Nernst sensing unit comprises the reference electrode and the first electrode; the second Nernst sensing unit comprises the reference electrode and the upper electrode or the lower electrode; the third Nernst sensing unit comprises the reference electrode and the third electrode; and the reference oxygen chamber is a closed chamber.

[0008] Optionally, the sensor further comprises: a first electrode arranged in the first chamber; an upper electrode and a lower electrode arranged oppositely in the second chamber; wherein the first pump unit comprises the outer electrode and the first electrode; the second pump unit comprises the outer electrode and the upper electrode or the lower electrode; the third pump unit comprises the outer electrode and the third electrode; the first Nernst sensing unit comprises the reference electrode and the first electrode; the second Nernst sensing unit comprises the reference electrode and the upper electrode or the lower electrode; the third Nernst sensing unit comprises the reference electrode and the third electrode; and the reference oxygen chamber is a closed chamber.

[0009] Optionally, the sensor further comprises: an excess air coefficient unit configured to obtain an excess air coefficient, wherein when the excess air coefficient is greater than a set threshold, the hydrocarbon measurement unit obtains the hydrocarbon concentration according to a voltage difference between the hydrocarbon electrode and the reference electrode.

[0010] Optionally, the hydrocarbon measurement unit further comprises: a hydrocarbon electrode protection layer covering a surface of the hydrocarbon electrode.

[0011] Optionally, the sensor further comprises: an oxygen measurement unit configured to measure an oxygen concentration.

[0012] Optionally, the sensor further comprises: an excess air coefficient unit configured to obtain an excess air coefficient, wherein when the excess air coefficient is less than a set threshold, the oxygen concentration is obtained according to an oxygen concentration at an outer electrode of the sensor and an oxygen concentration of the reference oxygen chamber; and when the excess air coefficient is greater than the set threshold, the oxygen concentration is obtained according to a current value between the first electrode of the sensor and the outer electrode.

[0013] Optionally, the sensor further comprises a calibration unit configured to calibrate a relationship between the hydrocarbon concentration and a voltage difference between the hydrocarbon electrode and the reference electrode at different oxygen concentrations, wherein the hydrocarbon measurement unit obtains the hydrocarbon concentration according to the relationship between the hydrocarbon concentration and the voltage difference between the hydrocarbon electrode and the reference electrode at the different oxygen concentrations.

[0014] Optionally, the sensor further comprises a heater configured to heat the first chamber, the second chamber and the third chamber.

[0015] According to another aspect of the present application, there is provided a combustion system comprising a combustion engine and a sensor as described above connected to the combustion engine to detect exhaust gas of the combustion engine.

[0016] The sensor according to the embodiments of the present application and the combustion system comprising the same additionally design a hydrocarbon electrode to measure the hydrocarbon concentration, and integrate the nitrogen oxide measurement and the hydrocarbon measurement.

[0017] Further, the sensor integrates the oxygen, nitrogen oxide and hydrocarbon measurement capabilities.

[0018] Further, the sensor adopts different measurement methods at different excess air coefficients to ensure the accuracy of the measurement.

[0019] Further, the sensor calibrates the relationship between the hydrocarbon concentration and the EMF at different oxygen concentrations, and measures the hydrocarbon concentration according to the calibrated relationship to ensure the accuracy of the hydrocarbon concentration measurement. BRIEF DESCRIPTION OF DRAWINGS

[0020] The above and other objects, features and advantages of the present application will become more apparent from the following description when taken in conjunction with the accompanying drawings, in which:

[0021] Figure 1 A structure schematic diagram of a sensor according to an embodiment of the present application is shown.

[0022] Figure 2 A measurement principle schematic diagram of a sensor according to an embodiment of the present application when the excess air coefficient is less than a set threshold is shown.

[0023] Figure 3 A measurement principle schematic diagram of a sensor according to an embodiment of the present application when the excess air coefficient is greater than a set threshold is shown.

[0024] Figure 4 A hydrocarbon measurement principle schematic diagram of a sensor according to an embodiment of the present application is shown.

[0025] Figure 5 A hydrocarbon concentration calibration schematic diagram according to an embodiment of the present application is shown. DETAILED DESCRIPTION

[0026] Various embodiments of the present application will be described in greater detail below, with reference to the accompanying drawings. In the drawings, like reference numerals can refer to like elements, and the various elements can be drawn in a not-to-scale manner. Also, some elements can not be shown to scale in the drawings.

[0027] The specific embodiments of the present application will be further described below with reference to the drawings and embodiments. Many specific details of the present application are described below in order to provide a thorough understanding of the present application. However, it will be apparent to one skilled in the art that the present application can be implemented without these specific details.

[0028] It is to be understood that when a layer, a region, or a component is referred to as being "on" or "above" another layer, another region, or another component, it can be directly on or above the other layer, the other region, or the other component, or intervening layers or regions can be present therebetween. Also, when a layer, a region, or a component is referred to as being "under" or "below" another layer, another region, or another component, it can be directly under or below the other layer, the other region, or the other component, or intervening layers or regions can be present therebetween.

[0029] According to an aspect of the present application, a sensor is provided. The sensor includes a reference oxygen chamber, a first chamber, a second chamber, a third chamber, a nitrogen oxide measuring unit, and a carbon hydrogen measuring unit. The nitrogen oxide measuring unit is located in the first chamber and / or the second chamber and / or the third chamber, for example. The sensor according to embodiments of the present application is obtained by adding the carbon hydrogen measuring unit to a conventional nitrogen oxide sensor, for example.

[0030] Specifically, the first chamber is connected to the outside through a first diffusion passage. The second chamber is connected to the first chamber through a second diffusion passage. The third chamber is connected to the second chamber through a third diffusion passage.

[0031] The nitrogen oxide measuring unit is used to measure a nitrogen oxide (NOx) concentration.

[0032] The carbon hydrogen measuring unit is used to measure a carbon hydrogen concentration. The carbon hydrogen measuring unit includes a carbon hydrogen electrode and a reference electrode. The reference electrode is disposed in the reference oxygen chamber. The carbon hydrogen measuring unit obtains the carbon hydrogen concentration according to a voltage difference between the carbon hydrogen electrode and the reference electrode.

[0033] Figure 1 A structure diagram of a sensor according to embodiments of the present application is shown. The sensor according to embodiments of the present application is described in detail with reference to Figure 1As shown, the first chamber 100 is connected with the outside through a first diffusion channel 110, and a first pump unit is arranged in the first chamber 100, and a first Nernst sensing unit is formed between the first chamber 100 and a reference oxygen chamber 400. The first diffusion channel 110 comprises a first diffusion barrier 112 and a first slit 111.

[0034] The second chamber 200 is connected with the first chamber 100 through a second diffusion channel 210, and a second pump unit is arranged in the second chamber 200, and a second Nernst sensing unit is formed between the second chamber 200 and the reference oxygen chamber 400. The second diffusion channel 210 comprises a second diffusion barrier 212 and a second slit 211.

[0035] The third chamber 300 is connected with the second chamber 200 through a third diffusion channel 310, and a third pump unit is arranged in the third chamber 300, and a third Nernst sensing unit is formed between the third chamber 300 and the reference oxygen chamber 400. The third diffusion channel 310 comprises a third diffusion barrier 312 and a third slit 311.

[0036] The sensor further comprises an upper electrode 501 and a lower electrode 502 arranged oppositely. The upper electrode 501 and the lower electrode 502 (auxiliary pump inner electrode) are, for example, platinum electrodes, and are arranged in the second chamber 200.

[0037] The outer electrode 503 is, for example, a platinum electrode. A third electrode (measurement pump electrode) 505 is arranged in the third chamber 300.

[0038] A first electrode 504 is arranged in the first chamber 100. The third electrode 505 is arranged in the third chamber 300. A reference electrode 506 is arranged in the reference oxygen chamber 400. Among them, the first pump unit comprises the common electrode 503 and the first electrode 504; the second pump unit comprises the common electrode 503 and the upper electrode 501 or the lower electrode 502; the third pump unit comprises the common electrode 503 and the third electrode 505. The first Nernst sensing unit comprises the reference electrode 506 and the first electrode 504; the second Nernst sensing unit comprises the reference electrode 506 and the upper electrode 501 or the lower electrode 502; the third Nernst sensing unit comprises the reference electrode 506 and the third electrode 505. Optionally, the reference oxygen chamber 400 is a closed chamber, which can avoid the pollution of waste gas to the reference oxygen chamber 400.

[0039] Optionally, the carbon-hydrogen electrode 702 is a gold (Au) electrode. A carbon-hydrogen electrode protective layer 701 covers the surface of the carbon-hydrogen electrode. The first electrode 504 is, for example, a platinum-gold electrode. The third electrode 505 is, for example, a measurement pump platinum-rhodium electrode, and the surface of the third electrode 505 is covered with a measurement pump electrode protective layer. Optionally, the sensor further comprises a heater 600. The heater 600 is used for heating the first chamber 100, the second chamber 200 and the third chamber 300.

[0040] As shown in Figure 1 Ip0 is the limiting current of the main pump oxygen. Ip1 is the auxiliary pump oxygen current. Ip2 is the nitrogen oxide measurement current. Vref0 is the main pump Nernst voltage. Vref1 is the auxiliary pump Nernst voltage. Vref2 is the measurement pump Nernst voltage. Vref3 is the hydrocarbon measurement EMF voltage.

[0041] In an optional embodiment of the present application, the sensor is applied to the exhaust detection of a lean burn engine. The sensor has oxygen and nitrogen oxide, hydrocarbon measurement capabilities. Optionally, when the excess air ratio (lambda) is equal to 1 (set threshold), the oxygen concentration is measured using the Nernst voltage method and the nitrogen oxide concentration is output; when the lambda is greater than 1, the oxygen concentration is measured using the limiting current method and the nitrogen oxide concentration is output; when the lambda is greater than 1, the carbon and hydrogen concentration is measured by the electrode and output.

[0042] Figure 2 The measurement principle diagram of the sensor according to the embodiment of the present application when the excess air ratio is less than the set threshold is shown. Figure 3 The measurement principle diagram of the sensor according to the embodiment of the present application when the excess air ratio is greater than the set threshold is shown. Specifically, in combination with Figure 2 and Figure 3 As shown, the sensor further comprises an oxygen measurement unit and an excess air ratio unit. The oxygen measurement unit is used to measure the oxygen concentration. The excess air ratio unit is used to obtain the excess air ratio.

[0043] When the excess air ratio is equal to the set threshold (1), the concentration of nitrogen oxide is obtained according to the Nernst voltage method. When the excess air ratio is greater than the set threshold, the concentration of nitrogen oxide is obtained according to the current between the outer electrode and the third electrode.

[0044] When the excess air ratio is greater than the set threshold, the hydrocarbon measurement unit obtains the hydrocarbon concentration according to the voltage difference between the hydrocarbon electrode and the reference electrode.

[0045] Referring to Figure 2 When the excess air ratio is less than the set threshold (1), the oxygen concentration is measured using the Nernst voltage method, and the measured oxygen concentration is obtained according to the oxygen concentration at the outer electrode and the oxygen concentration of the reference oxygen chamber. Specifically, for example, the measured oxygen concentration is obtained according to the formula . Wherein P2 is the oxygen concentration of the reference oxygen chamber, P1 is the oxygen concentration at the outer electrode, and the Nernst voltage represents the oxygen concentration value of P1.

[0046] Referring to Figure 3 When the excess air ratio is greater than the set threshold (1), the measured oxygen concentration is obtained according to the current value between the first electrode and the outer electrode. Specifically, a certain voltage is applied between the outer electrode and the first electrode, and the generated current represents the oxygen concentration value.

[0047] Figure 4 A schematic diagram of carbon-hydrogen measurement principle of the sensor according to an embodiment of the present application is shown. Figure 5 A schematic diagram of carbon-hydrogen concentration calibration according to an embodiment of the present application is shown. In an alternative embodiment of the present application, carbon-hydrogen concentration is measured by calibrating the relationship between carbon-hydrogen and EMF at different oxygen concentrations.

[0048] In particular, the sensor further comprises a calibration unit. The calibration unit is configured to calibrate the relationship between carbon-hydrogen concentration and the voltage difference between the carbon-hydrogen electrode and the reference electrode at different oxygen concentrations. The carbon-hydrogen measurement unit is configured to obtain the measured carbon-hydrogen concentration according to the relationship between carbon-hydrogen concentration and the voltage difference between the carbon-hydrogen electrode and the reference electrode at different oxygen concentrations.

[0049] According to another aspect of the present application, there is provided a combustion system (engine system). The combustion system comprises a combustion (internal combustion) engine and a sensor as described above. The sensor is connected to the combustion engine to detect the exhaust gas of the combustion engine. Optionally, the sensor is a multi-gas detection sensor for lean-burn engine aftertreatment.

[0050] It is to be understood that the terminology used herein such as first and second, and the like, is only used to distinguish one entity or action from another entity or action, and does not necessarily require or imply any such actual relationship or order between such entities or actions. Moreover, the terms "comprises", "comprising", or any other variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but can include other elements not expressly listed or inherent to such process, method, article, or apparatus. An element proceeded by "comprises... a" does not, without more constraints, exclude the existence of additional identical elements in the process, method, article, or apparatus that comprises the element.

[0051] In light of the above description of embodiments according to the present application, it will be apparent to those of ordinary skill in the art that many changes and modifications can be made to the embodiments described without departing from the scope of the present application. The embodiments have been chosen and described in some detail to provide the best understanding of the principles and applications of the present application, the only limitations being the scope of the claims and equivalents thereof.

Claims

1. A sensor, comprising: a reference oxygen chamber; a first chamber connected with the outside through a first diffusion channel; a second chamber connected with the first chamber through a second diffusion channel; a third chamber connected with the second chamber through a third diffusion channel; a nitrogen oxide measuring unit for measuring a nitrogen oxide concentration; and a carbon hydrogen measuring unit for measuring a carbon hydrogen concentration, wherein the first chamber is provided with a first pump unit, and a first Nernst sensing unit is formed between the first chamber and the reference oxygen chamber; the second chamber is provided with a second pump unit, and a second Nernst sensing unit is formed between the second chamber and the reference oxygen chamber; and the third chamber is provided with a third pump unit, and a third Nernst sensing unit is formed between the third chamber and the reference oxygen chamber; the carbon hydrogen measuring unit comprises: a carbon hydrogen electrode; and a reference electrode provided in the reference oxygen chamber; the carbon hydrogen measuring unit obtains the carbon hydrogen concentration according to a voltage difference between the carbon hydrogen electrode and the reference electrode; the sensor further comprises: an outer electrode; a third electrode provided in the third chamber; and an excess air coefficient unit for obtaining an excess air coefficient, wherein when the excess air coefficient is equal to a set threshold value, the nitrogen oxide concentration is obtained according to a Nernst voltage method; when the excess air coefficient is greater than the set threshold value, the nitrogen oxide concentration is obtained according to a current between the outer electrode and the third electrode; and when the excess air coefficient is greater than the set threshold value, the carbon hydrogen measuring unit obtains the carbon hydrogen concentration according to the voltage difference between the carbon hydrogen electrode and the reference electrode. The sensor further comprises: a first electrode provided in the first chamber; and oppositely arranged upper and lower electrodes provided in the second chamber, wherein the first pump unit comprises the outer electrode and the first electrode; the second pump unit comprises the outer electrode and the upper electrode or the lower electrode; the third pump unit comprises the outer electrode and the third electrode; the first Nernst sensing unit comprises the reference electrode and the first electrode; the second Nernst sensing unit comprises the reference electrode and the upper electrode or the lower electrode; the third Nernst sensing unit comprises the reference electrode and the third electrode; and the reference oxygen chamber is a closed chamber. The carbon hydrogen measuring unit further comprises: a carbon hydrogen electrode protection layer covering a surface of the carbon hydrogen electrode. The sensor further comprises: an oxygen measuring unit for measuring an oxygen concentration, wherein when the excess air coefficient is less than the set threshold value, the oxygen concentration is obtained according to an oxygen concentration at the outer electrode of the sensor and an oxygen concentration of the reference oxygen chamber; and when the excess air coefficient is greater than the set threshold value, the oxygen concentration is obtained according to a current value between the first electrode and the outer electrode. The sensor further comprises: a calibration unit for calibrating a relationship between carbon hydrogen concentrations and voltage differences between the carbon hydrogen electrode and the reference electrode under different oxygen concentrations. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ 2. The sensor of claim 1, wherein, ​ ​ ​ ​ ​ ​ 3. The sensor of claim 1, wherein, ​ ​ 4. The sensor of claim 2, wherein, ​ ​ 5. The sensor of claim 4, wherein, ​ ​ 6. The sensor of claim 1, wherein, ​ ​ The carbon-hydrogen measuring unit obtains the carbon-hydrogen concentration according to a relationship between the carbon-hydrogen concentration under the different oxygen concentrations and the voltage difference between the carbon-hydrogen electrode and the reference electrode.

7. The sensor of claim 1, wherein, The sensor further comprises: A heater for heating the first chamber, the second chamber and the third chamber.

8. A combustion system comprising: a combustion engine; and the sensor of any one of claims 1-7, connected to the combustion engine to detect exhaust gas of the combustion engine.

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