A control method for avoiding fuel shortage in a solid oxide fuel cell system

Abstract

The invention discloses a control method for avoiding fuel deficiency of a solid oxide fuel cell. The control method comprises the steps that a corresponding optimal power increasing speed is obtained through simulated analysis under a condition of setting different delayed times when the system tracks an external load to realize a power increasing switching; therefore, the system can satisfy the rapid load tracking capability without causing fuel deficiency; a power reference trajectory is designed based on model prediction control; a target constrained trajectory can be tracked rapidly and smoothly based on the power output value of the system by combination of the power reference trajectory, so that the purpose of the rapid and safe load tracking of the SOFC (solid oxide fuel cell) independent power generation system is achieved. In the system power switching process, the optimal power increasing speed under the set fuel delayed time is obtained; the power reference trajectory is designed based on the model prediction control (MPC) method, so that the limitation of the power increasing rate is realized; the fuel deficiency problem caused by rapid load tracking is solved; and therefore, the control method is applicable to practical engineering applications.

Description

technical field [0001] The invention belongs to the field of solid oxide fuel cells, and more specifically, relates to a control method for a solid oxide fuel cell system to avoid fuel shortage, and specifically relates to the power switching of the solid oxide fuel cell system under the condition of limiting the power increase rate, The load tracking is realized through the designed power reference trajectory, and the system does not produce the control method of fuel shortage problem. Background technique [0002] Solid Oxide Fuel Cell (SOFC for short) is an all-solid-state chemical power generation device that directly converts chemical energy stored in fuel and oxidant into electrical energy in an efficient and environmentally friendly manner at medium and high temperatures. , no pollution, all solid state, no mechanical vibration and wide adaptability to a variety of hydrocarbon fuel gases, making it one of the most attractive green power generation methods in the 21st ...

AI Technical Summary

Problems solved by technology

Some representative scientific research institutions and companies in the world of SOFC have gradually perfected their SOFC technology, and have successful records of continuous operation for tens of thousands of hours without attenuation. Due to the harsh environmental conditions and the lack of complete technology and optimized control methods in engineering applications, the performance of the system cannot be compared with that obtained by the test bench.

[0004] Among them, for fast load tracking (power increase), if the fastest switching time is ensured, when the external load of the SOFC system undergoes a step change in the output power after switching, the fuel will be consumed very quickly due to the electrochemical reaction, and the time is Milliseconds will instantly increase the demand for fuel, and there is a delay in the gas pipeline, the time is seconds, the time difference between the two makes the required fuel in the stack not be supplied in time, resulting in a fuel shortage problem , so that the anode material of the stack is oxidized, and the temperature of the stack changes drastically, which can easily cause degradation and damage of the battery material

In addition, the SOFC system is a typical strongly coupled, multivariable, nonlinear system, and it is expensive to manufacture. In fact, it is impossible to study the system through repeated experiments. simulation Research

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