Vehicle-mounted fuel cell water management system and control method thereof

Abstract

The invention discloses a vehicle-mounted fuel cell water management system and a control method thereof. The system comprises an electric pile, a hydrogen path system, an air path system, a nitrogenpath system and a hydrogen circulation system. The hydrogen path system comprises a hydrogen tank, an electromagnetic valve and a pressure reducing valve, the nitrogen path system comprises a nitrogentank, an electromagnetic valve and a pressure reducing valve, the two systems are connected in parallel, and the temperature and pressure of the path are measured by a temperature sensor and a pressure sensor; the air path system comprises an electromagnetic valve, an air filter, an air compressor, a temperature sensor, a pressure sensor and a flow meter; the hydrogen circulation system comprisesa gas-liquid separator, a liquid storage tank, an electromagnetic valve, a humidifier and a hydrogen circulating pump. The invention further discloses a control method of the system. Firstly, theoretical cathode pressure drop of the fuel cell is calculated through a formula, and then the theoretical cathode pressure drop is compared with an actual pressure drop value to judge the internal water content of the fuel cell so as to execute corresponding water management operation to prevent the fuel cell from water logging or membrane drying.

Description

technical field [0001] The invention belongs to the field of fuel cell vehicles, and in particular relates to a vehicle-mounted fuel cell water management system and a control method thereof. Background technique [0002] A fuel cell is a device that converts chemical energy into electricity, water and heat through the chemical reaction of hydrogen and the anode. As a new type of clean energy, fuel cells have the advantages of high efficiency, quietness, environmental friendliness, simple structure, high energy density, and high safety. [0003] The water content of the proton exchange membrane greatly affects the working efficiency of the fuel cell. Membrane flooding will cause large fluctuations in voltage, resulting in unstable output power and reducing the service life of the fuel cell. Membrane drying will reduce the conductivity of the proton exchange membrane and increase the ohmic impedance, thereby reducing the output power of the fuel cell. Therefore, a reasonab...

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Problems solved by technology

Existing patents such as the Chinese Patent Publication No. CN106450383B, published on 2019-06-25, disclose a proton exchange membrane fuel cell water management system and its working method. The invention mainly uses the installed water level monitoring device to measure The change of the water level inside the fuel cell and the water management of the fuel cell are performed, but the system structure is relatively complicated; another example is the patent application publication number CN109799457A, the publication date is 2019-05-24, which discloses a fuel cell water management monitoring The system and its working method can not only discover and adjust the water balance problem of the fuel cell in time, but also recycle the waste water with waste heat generated during the operation of the fuel cell, but the system requires many components and the control The method is complicated; another example is that the Chinese patent publication number is CN110010932A, and the publication date is 2019-07-12, which discloses a method of selecting different drainage and exhaust circuits under different working conditions to realize circulating hydrogen in the low-pressure hydrogen pipeline due to The liquid water formed by condensation is separated through the auxiliary steam-water separator, and the liquid water is discharged or the hydrogen is humidified to prevent insufficient or excessive humidification of the anode of the stack and improve the performance of the stack, but the water content of the cathode of the stack is not considered.

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