Hydrogen production system and control method of hydrogen production system

Abstract

The invention provides a hydrogen production system and a control method of the hydrogen production system. The hydrogen production system comprises an electrolyte storage device, a heat exchanger, a preheater, an electrolytic bath, a cascade heat storage device and a cooling device, and the electrolyte storage device, the hot side of the heat exchanger, the cold side of the preheater and the electrolytic bath are communicated to form a reaction loop; the cascade heat storage device comprises at least two heat release sides, the output temperatures of the heat release sides are different, one heat release side communicates with the heat side of the preheater to form a preheating loop, and the other heat release sides are connected into the heating loop in a one-to-one correspondence mode. The cold side of the heat exchanger communicates with the heat storage side of the heat storage device to form a heat storage loop. According to the hydrogen production system provided by the invention, a large amount of invalid waste heat emitted in the reaction process is effectively stored, low-quality heat energy is recycled, the recycled heat is used for preheating the electrolyte, cold start is converted into hot start, the start time is shortened, the hydrogen production speed and efficiency are improved, energy is saved, consumption is reduced, and the operation cost is reduced.

Description

technical field [0001] The present application relates to the technical field of hydrogen production by electrolysis of water, in particular to a hydrogen production system and a control method for the hydrogen production system. Background technique [0002] At present, the commonly used methods of hydrogen production by electrolysis of water include alkaline electrolysis of water for hydrogen production, proton exchange membrane electrolysis of water for hydrogen production and solid oxide electrolysis of water for hydrogen production. Alkaline electrolytic water hydrogen production technology is relatively simple and low cost, but there are problems such as low hydrogen production efficiency and low hydrogen purity, and the electrolyte is alkaline, which poses overall safety hazards. Hydrogen production by solid oxide electrolysis of water requires a relatively high temperature for electrolysis, resulting in high energy consumption and large heat loss. Proton exchange me...

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Problems solved by technology

[0003] However, in practical engineering applications, the proton exchange membrane water electrolysis hydrogen production system has the following technical problems: First, when the system is cold started, the cold water directly enters the electrolyzer and relies on direct current to heat the electrolyte. Not only the reaction rate is slow, but the catalytic activity and hydrogen production Low efficiency and long start-up time make it difficult to maintain the constant temperature of the electrolytic cell; second, electrolysis will generate a large amount of waste heat that needs to be evacuated, and this waste heat cannot be effectively recycled. On the one hand, if the waste heat is not evacuated in time, it will produce membrane electrode Serious problems such as overheating, catalyst shedding, electrode performance attenuation, etc. On the other hand, the current heat evacuation is often achieved through cooling towers or chillers without waste heat recovery, which does not meet the requirements of energy saving and consumption reduction

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