Method for measuring oxygen concentration in the cathode of a fuel cell system

A fuel cell, usually referred to as a hydrogen fuel cell (proton exchange membrane fuel cell), is a power generation device that converts chemical energy into electrical energy through a redox reaction between hydrogen and oxygen. Unlike ordinary batteries, fuel cells only need to provide stable hydrogen and oxygen to continuously provide stable electrical energy.

In order to achieve a certain accuracy in the measurement of the fuel cell, it is generally required that the fuel cell has a higher response value to the oxygen energy in the sample gas, that is, when the sample gas contains a certain degree of oxygen, a higher current can be generated strength, which requires the electric stage to have a strong reaction efficiency.

The measurement signal of the fuel cell is proportional to the oxygen partial pressure in the sample gas. The measurement signal is not only related to the oxygen concentration in the sample gas, but also proportional to the pressure of the sample gas. Therefore, the fuel cell must be kept as stable as possible so that the readings can be accurate. If a large number of oxygen molecules enter the interior of the fuel cell, only after the oxidation reaction is completed can the oxygen molecule content in the sample gas be re-responsive. Therefore, the fuel cell has the characteristics that the oxygen reading rises quickly but falls slowly. At this time, the flow rate of the sample gas can be appropriately increased, and the replacement rate of the sample gas in the fuel cell can be increased, so that the sensor can respond faster to the reading of the oxygen content in the sample gas.

There are many kinds of instruments for measuring oxygen, which can be divided into: chemical cell type (primary cell, fuel cell, Hertz cell), concentration cell type (zirconia cell and variable frequency limiting current cell) and gas chromatography law, etc. However, in the gas process analysis system and industrial production and application, the fuel cell oxygen gas analyzer is especially suitable for professional gas production and electronic equipment due to its simple measurement principle, easy maintenance and operation, high measurement accuracy and good stability. industry and other industries.

The core component of the fuel cell oxygen gas analyzer is the sensor. A sensor is a device that converts chemical energy into electrical energy, generally consisting of a cathode, an anode and an electrolyte. When the oxygen in the sample gas enters the fuel cell, it converts the acquired electrons into an ionic state, and then transfers through the electrolyte and finally chemically reacts with the anode. One of the reactants is the oxygen in the sample gas, and the other reactant is the anode stored in the battery. The comprehensive reaction is the oxidation reaction between the oxygen molecules in the sample gas and the anode, and finally the oxide of the anode material is generated. This reaction is similar to the reaction mechanism of a fuel cell, so this type of sensor is called a fuel cell type. In the chemical reaction, electron migration occurs between the anode and the anode. If a wire is used to connect the common connection, a current will be generated. The magnitude of the current is proportional to the number of oxygen molecules entering the sensor. Therefore, as long as the anode and the anode are accurately measured The current between the anodes gives the oxygen content in the sample gas.

British SST threaded high temperature zirconia oxygen sensor (O2 sensor)

O2S-FR-T2-18C is a zirconia oxygen sensor, the sensitive element is zirconia, two zirconia discs are used, and a sealed space is in the middle. One of the functions of the disk is the reversible oxygen pump, which in turn fills the sample gas and evacuates this small space. The other disc is used to measure the ratio of oxygen differential pressure to obtain the corresponding sensing voltage. When the zirconia disc operates as an oxygen pump, the required temperature of 700 °C is generated by a heating element (the matching circuit board O2I-FLEX-092 can provide heating and linear analog output functions.). The time it takes for the oxygen pump to reach the rated minimum and maximum pressure in a small space has a corresponding relationship with the oxygen partial pressure in the environment.

Threaded high temperature zirconia oxygen sensor (O2 sensor) O2S-FR-T2-18C/B/A Features:

1) Oxidation range: 2mbar-3bar

2) Zirconia detection element

3) Non-consumable technology

4) No need for temperature temperature, no reference gas

5) High precision

6) Linear output signal

7) Work with external interface board

Threaded high temperature zirconia oxygen sensor (O2 sensor) O2S-FR-T2-18C/B/A Product parameters: