PSI - Issue 65

Golodnova A.I. et al. / Procedia Structural Integrity 65 (2024) 97–101 Golodnova A.I., Erpalov M.V. / Structural Integrity Procedia 00 (2024) 000–000

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individual elements of this technology have high mechanical fragility over a long period of operation due to the destruction of electrodes during electrolysis, which is one of the key problems of SOE operation. In the literature on the operation of electrochemical devices, Sciubba E. (2016), Wilberforce, T., (2017) and Dohle, H discuss that the main design features of GP (the length of the trajectory, the cross-sectional area of the channels and their number) affect the parameters of gas movement (velocity, flow, pressure, etc.), which, in turn, it affects the technological characteristics of the device (product composition, power consumption). Including the pressure drop, which affects the tightness of the device and depends on the mechanical strength, as noted. Structurally, the gas channels are located between the connecting plates and the electrodes. The design of the plates serves as the basis for the distribution of chemically active gases in the electrolyzer. Considering that the overall efficiency of the system depends on the performance of individual elements, the purpose of this study is to develop the interconnector itself. The purpose of this study is to critically evaluate the existing interconnector design. The article discusses in detail the various types of plates and evaluates the relationship of their design with the pressure drop in the device. The length of the trajectory determines the uniformity of the gas distribution in the fuel cell. Uniformity is necessary to prevent local overheating of the electrolyte, unstable current density and destruction of the device. Again, the geometry of the connecting element affects the rate of chemical reactions, which helps to avoid carbon deposits in the channels. For example, the geometry of parallel channels in the plate connector is one of the most widely used, but it has limitations related to the distribution of gas over the surface of the electrodes. Several studies have also been conducted to determine the effect of the pressure drop due to the geometry and length of the channels on the overall efficiency of the cells. Scientists Demin A. K. (2013), Bresler, L. H. (2023), Fussler C. (2015) consider various designs of interconnectors, due to the high cost of devices, a significant part of the research is devoted to the mathematical evaluation of the effectiveness of the design of individual elements. Today, numerical modeling is an additional method that allows us to evaluate the behavior of a full stack based on the interaction of many physical phenomena over the entire service life. In particular, he can estimate how much the operation of the device will be disrupted when changing the channel length parameter in the electrolyzer. Some conclusions have been drawn that the resistance in the geometric design of the interconnections and the size of the edges between the channels through which the electron flow passes largely determine the uniformity of the gas on the active surface of the cellblock. The correct selection of mathematical equations allows us to confirm the effectiveness of a certain design of electrochemical devices or their operating modes, as well as to evaluate the effectiveness during the estimated service life. In this case, we consider a system of equations (a mathematical model) showing the dependence of the length of the trajectory of changes in the pressure drop at the inlet and outlet of an electrochemical device. Similar dependencies were considered in the works of Qu, Z. (2008) and Chen, C. H. (2007). In real conditions, the high-pressure difference in fuel cells means that the number of reagents entering into the electrolysis reaction will be less, and this, in fact, will reduce the overall functionality of the battery cells. Thus, this phenomenon will not increase the efficiency of the system, since more hydrogen that is gaseous will be required to generate less current, which will increase the operating costs of the device. The uneven distribution of the reagent velocity and pressure in the fuel cell is due to the length of the channels in the connecting plates. These channels are designed in such a way that the synthesis gas easily exits the battery of cells and increases the active contact area of the gas stream with the electrodes on which the electrochemical reaction takes place. Melnikov V. B. (2024) discussed these indicators. Assumptions made when building the model: 1. The power characteristics of the electric circuit are constant (current I amperage and U voltage). 2. Initially, the characteristics of the reagents and products are set. The composition of the gas mixture at the entrance to the electrolyzer or the composition of the reaction products. ([H2O] [CO2] [H2]/ [H2O]” [CO2]” [H2]”). This indicator does not change when the geometric characteristics change. 3. The characteristics of the amount of the substance are constant. The gas flow rates at the inlet and outlet of the device know. 2. Description of the mathematical model