# US 2021/0239669 A1 · Intelligent nitrogen-oxygen sensor and detection method thereof

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- Number: US 2021/0239669 A1
- Document ID: US20210239669A1
- Status: Published application
- Kind: A1
- Application number: 16/980,379
- Filed: 2019-01-22
- Published: 2021-08-05
- Earliest claimed: 2018-02-11
- Assignees: Changzhou Lambda Electonic., Ltd
- Applicants: Changzhou Lambda Electonic., Ltd
- Inventors: Jiangtao Feng
- Web page: https://patentgrep.com/patent/US20210239669A1

## CPC

- G01N 33/0037: {NOx}
- F01N 3/2066: {Selective catalytic reduction [SCR]}
- F01N 3/208: {Control of selective catalytic reduction [SCR], e.g. by adjusting the dosing of reducing agent}
- F01N 3/32: using air pump (using jet air pumps F01N3/34; pumps in general F04)
- G01N 27/27: Association of two or more measuring systems or cells, each measuring a different parameter, where the measurement results may be either used independently, the systems or cells being physically associated, or combined to produce a value for a further parameter
- G01N 27/4071: {using sensor elements of laminated structure}
- G01N 27/419: Measuring voltages or currents with a combination of oxygen pumping cells and oxygen concentration cells
- F01N 2560/026: for measuring or detecting NOx
- F01N 2560/20: Sensor having heating means
- Y02A 50/20: Air quality improvement or preservation, e.g. vehicle emission control or emission reduction by using catalytic converters
- Y02T 10/12: Improving ICE efficiencies
- G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q)
- F01N: GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL-COMBUSTION ENGINES (arrangements in connection with gas exhaust of propulsion units in vehicles B60K13/00; combustion-air intake silencers specially adapted for, or arranged on, internal-combustion engines F02M35/00; protecting against, or damping, noise in general G10K11/16)
- Y02A: TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
- Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION

## Abstract

An intelligent nitrogen-oxygen sensor and a detection method thereof are disclosed. The sensor includes an induction chip. The induction chip includes a substrate unit, a printing function unit and a closed structural unit. The substrate unit includes an upper zirconia substrate (1), a middle zirconia substrate (2) and a lower zirconia substrate (3). The printing, function unit includes a common external electrode (11), a main pump internal electrode (12). an auxiliary pump internal electrode (13). a. mixed potential sensitive electrode (31), a measurement pump internal electrode (32), a reference air electrode (33), a first insulation coating layer (41), a second insulation coating layer (42), a heating circuit (43) and eight electrode contact points. The closed structural unit includes a first measurement cavity (21), a second measurement cavity (22) and a reference air passage (23).

## Claims

### Claim 1

An intelligent nitrogen-oxygen sensor comprising an induction chip, wherein the induction chip comprises a substrate unit, a printing function unit and a closed structural unit, wherein:
the substrate unit comprises an upper zirconia substrate (1), a middle zirconia substrate (2) and a lower zirconia substrate (3);
the printing function unit comprises a common external electrode (11), a main pump internal electrode (12), an auxiliary pump internal electrode (13), a mixed potential sensitive electrode (31), a measurement pump internal electrode (32), a reference air electrode (33), a first insulation coating layer (41), a second insulation coating layer (42), a heating circuit (43) and eight electrode contact points;
the closed structural unit comprises a first measurement cavity (21), a second measurement cavity (22) and a reference air passage (23);
the common external electrode (11) is connected with a common electrode contact point (111) through a lead wire, and is printed on an upper end surface of the upper zirconia substrate (1);
the main pump internal electrode (12), the auxiliary pump internal electrode (13) and lead wires thereof are printed on a lower end surface of the upper zirconia substrate (1);
the main pump internal electrode (12) and the auxiliary pump internal electrode (13) are respectively connected with a first electrode contact point (121) and a second electrode contact point (131), both of which are printed on the upper end surface of the upper zirconia substrate (1), through the lead wires via through-holes in the upper zirconia substrate (1);
the mixed potential sensitive electrode (31) and the measurement pump internal electrode (32) are printed on an upper end surface of the lower zirconia substrate (3), and are respectively connected with a third electrode contact point (311) and a fourth electrode contact point (321) both of which are located at two sides of the lower zirconia substrate (3) through lead wires;
the reference air electrode (33) and a lead wire thereof are printed on the upper end surface of the lower zirconia substrate (3), and the reference air electrode (33) is connected with a fifth electrode contact point (331) which is located at a lower end surface of the lower zirconia substrate (3) via a through-hole in the lower zirconia substrate (3);
the first insulation coating layer (41) and the second insulation coating layer (42) are directly printed on the lower end surface of the lower zirconia substrate (3), and wrap the heating circuit (43);
a length of the second insulation coating layer (42) is smaller than a length of the first insulation coating layer (41), such that the fifth electrode contact point (331), a sixth electrode contact point (431) and a seventh electrode contact point (432) are exposed to air;
the first measurement cavity (21), the second measurement cavity (22) and the reference air passage (23) are provided on the middle zirconia substrate (2) through punching process, and a first diffusion barrier layer (11) and a second diffusion barrier layer (221) are provided on the middle zirconia substrate (2).

### Claim 2 (depends on 1)

The intelligent nitrogen-oxygen sensor according to claim 1, wherein the mixed potential sensitive electrode (31) is provided within the first measurement cavity (21).

### Claim 3 (depends on 1)

The intelligent nitrogen-oxygen sensor according to claim 1, wherein the first diffusion barrier layer (211) is provided at a front end of the first measurement cavity (21), the second diffusion barrier layer (221) is provided at a rear end of the first measurement cavity (21).

### Claim 4 (depends on 1)

The intelligent nitrogen-oxygen sensor according to claim 1, wherein the mixed potential sensitive electrode (31) is made from NiO and ZrO2 with a mass ratio in a range from 2:1 to 1:1.

### Claim 5 (depends on 1)

The intelligent nitrogen-oxygen sensor according to claim 1, further comprising: a main pump unit VP0 for connecting the common external electrode (11) with the main pump internal electrode (12), an auxiliary pump unit VP1 for connecting the common external electrode (11) with the auxiliary pump internal electrode (13), a measurement pump unit VP2 for connecting the common external electrode (11) with the measurement pump internal electrode (32), a first measurement cavity oxygen concentration difference battery unit VO for connecting the main pump internal electrode (12) with the reference air electrode (33), a second measurement cavity oxygen concentration difference battery unit V1 for connecting the reference air electrode (33) with the auxiliary pump internal electrode (13), a measurement pump catalytic decomposition electrode oxygen concentration difference battery unit V2 for connecting the reference air electrode (33) with the measurement pump internal electrode (32), a mixed potential measurement unit VR for connecting the main pump internal electrode (12) with the mixed potential sensitive electrode (31).

### Claim 6 (depends on 1)

A detection method of the intelligent nitrogen-oxygen sensor according to claim 1, the detection method comprising steps of:
(S1) the exhaust gas entering the first measurement cavity (21) through the first diffusion harder layer (211), the main pump unit VP0 maintaining an oxygen concentration V0 of the first measurement cavity (21) to a certain constant value through feedback adjustment, oxidizing HC, CO and H2 in the exhaust gas, ensuring a concentration of NO and NO2 is stable, wherein a main pump limit current IP0 produced by the main pump unit is in direct proportion to an air-fuel ratio of the exhaust gas;
(S2) under a condition that the oxygen concentration in the first measurement cavity (21) is fixed, detecting a potential difference Vr between the mixed potential sensitive electrode (31) and the main pump internal electrode (12), and obtaining a relative content ratio of NO to NO2, wherein Vr=NO/NO2;
(S3) gas in the first measurement cavity (21) diffusing into the second measurement cavity (22) through the second diffusion barrier layer (221), maintaining an oxygen concentration V1 of the second measurement cavity (22) through the auxiliary pump unit VPT at a lower constant value, converting NO2 into NO, and determining an amount of oxygen that enters the second measurement cavity (22) through an auxiliary pump limit current IPI produced by the auxiliary pump unit;
(4) decreasing an oxygen concentration around a catalytic decomposition electrode in the second measurement cavity (22) through the measurement pump unit VP2 to V2, completing decomposing NO into N2 and O2 through the measurement pump internal electrode (32), pumping the decomposed 02 through the measurement pump unit, and forming a measurement pump current IP2, wherein the measurement pump current IP2 is in direct proportion to a total concentration of NOX, here IP2=NOX; and
(5) calculating a ratio of the measurement pump current IP2 and the auxiliary pump limit current IP1, obtaining the total concentration of NOX, and calculating concentrations of NO and NO2 based on the potential difference Vr of the mixed potential detection unit, respectively.