A kind of lohc fuel cell power generation system and method

Abstract

The invention discloses a LOHC fuel cell power generation system and method, which is composed of fuel cell, high temperature heat pump, LOHC dehydrogenation and Rankine cycle four subsystems. fuel cell subsystem, the H 2 The chemical energy is converted into electrical energy; the high-temperature heat pump subsystem converts the low-temperature thermal energy of the fuel cell into high-temperature thermal energy; the LOHC dehydrogenation subsystem utilizes high-temperature thermal energy to realize LOHC dehydrogenation; the Rankine cycle subsystem converts the residual thermal energy of the system into electrical energy. In the present invention, the waste heat generated by the fuel cell is quickly absorbed and taken away by the working medium, ensuring efficient and stable operation of the battery. A part of the heat is used to drive the Rankine cycle to generate electricity. The generated electric energy can be used for internal consumption of the system, and a part of the heat is used for LOHC dehydrogenation. Generated H 2 For fuel cell use. The system and method solve the problem of energy waste caused by the mismatch between the operating temperature of the fuel cell and the LOHC dehydrogenation temperature, reduce the adverse effect of dehydrogenation reaction energy consumption on the power generation efficiency of the fuel cell, and improve the overall energy utilization level.

Description

technical field [0001] The invention belongs to the field of hydrogen energy, and in particular relates to a LOHC fuel cell power generation system and method. Background technique [0002] h 2 As a truly clean fuel, it is the key to solving future environmental problems. Its production, storage, transportation and use are different from traditional fuels. The limitation of energy density per unit volume makes it difficult for long-distance transportation to be as convenient and efficient as coal and oil. h 2 The standard boiling point (-253°C) of hydrogen is much lower than that of natural gas (-162°C), the storage and transportation costs of liquid hydrogen are too high, and the problem of hydrogen embrittlement during pipeline transportation is difficult to solve in the short term. Liquid Organic Hydrogen Carrier (LOHC) is a potential H 2 The storage method realizes high-density hydrogen storage through the reversible catalytic hydrogenation and dehydrogenation reacti...

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Problems solved by technology

In addition, due to the generally lower boiling point and thermal decomposition temperature of LOHC, the reaction endothermic heat is higher (~60kJ / mol-H 2 ), in order to ensure a high dehydrogenation rate and conversion rate, the reaction temperature window is generally narrow, and it is difficult to maintain the temperature window

[0004] Some scholars have proposed to use the waste heat of fuel cells to realize LOHC dehydrogenation, but the temperature mismatch between the two makes its implementation difficult.

Some scholars pointed out that using H 2 Low-temperature catalytic combustion provides energy for the LOHC dehydrogenation reaction, but the lower heat transfer coefficient on the flue gas side will greatly increase the size of the equipment

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