8results about How to "Reduce flooding" patented technology

The application belongs to the technical field of proton exchange membrane fuel cell, and relates to a hydrophobicity-adjustable alloy nanotube array electrode for fuel cell and preparation and application thereof. Specifically, the application comprises preparation of metal nanotube array, alloying and hydrophobization of the metal nanotube array, and assembly of the membrane electrode. First, a metal nanotube array is constructed on a substrate surface through a two-step hydrothermal method; then, a hydrophobic substance is introduced into the metal nanotube array by means of immersion or ultrasonic spraying; then, pyrolysis is performed to realize alloying and hydrophobization of the nanotube array; finally, the nanotube array is transferred to a proton membrane, and the membrane electrode is cleaned. The membrane electrode can be applied to a proton exchange membrane fuel cell. The hydrophobicity-adjustable nanotube array electrode prepared by the application has the advantages of high catalyst activity and stability, low platinum loading, good water management, and easy scaling-up.

The invention belongs to the technical field of fuel cells, and particularly relates to a PEM fuel cell membrane electrode and a preparation method thereof. The preparation method of the PEM fuel cell membrane electrode provided by the invention comprises the following steps: preparing composite hydrophilic resin and composite hydrophobic resin, preparing cathode first catalyst layer slurry by adopting the composite hydrophilic resin, and controlling the spraying rate to obtain a cathode first catalyst layer of which the content of the composite hydrophilic resin is gradually changed; preparing cathode second catalyst layer slurry by adopting composite hydrophobic resin, controlling the spraying rate to obtain a cathode second catalyst layer with gradually changed composite hydrophobic resin content, and performing transfer printing and hot pressing on the cathode first catalyst layer, the cathode second catalyst layer, the anode catalyst layer and a proton membrane to obtain a membrane electrode, wherein the content of the composite hydrophilic resin in the first catalyst layer of the cathode is uniformly reduced from top to bottom along the gravity direction, and the content of the composite hydrophobic resin in the second catalyst layer of the cathode is uniformly increased from top to bottom along the gravity direction.

This application discloses a method for inverting insect wingbeat frequency based on initial phase calculation, relating to the field of radar measurement technology. The method includes: establishing a radar echo model of insect wingbeat motion containing amplitude and phase initial phases; acquiring micro-motion signals from the collected insect echoes based on the model to generate a micro-Doppler spectrum; calculating the phase initial phase value of the insect wingbeat based on the micro-Doppler spectrum; constructing a phase compensation factor based on the phase initial phase value to obtain a wingbeat parameter plane; detecting energy peaks in the wingbeat parameter plane based on the phase compensation factor; and determining the insect's wingbeat frequency based on the position of the energy peaks. This application, by introducing phase and amplitude initial phases, recreates the dual physical processes of wing movement and body micro-motion during insect wingbeat, making the radar echo model highly consistent with the actual signal generation mechanism, reducing errors, and improving anti-interference capabilities.

The invention relates to a dual-module intercooler type fuel cell cathode inlet temperature and humidity cooperative control method. The method comprises the steps that fuel cell cathode air inlet real-time state parameters and operation parameters are obtained, a multivariable coupling prediction model is constructed after preprocessing, and a temperature and humidity reference and an oxygen stoichiometric ratio target reference are set in combination with heat exchange characteristics of a dual-module intercooler; then the core body heat exchange distribution proportion is regulated and controlled, humidification adjustment is matched, and the core body heat exchange distribution proportion and the humidification adjustment intensity are dynamically adjusted according to the real-time working condition; comparing the deviation between the adjusted actual temperature and humidity and the target temperature and humidity reference, and correcting the heat exchange distribution proportion and the humidifying adjustment parameter through a dynamic constraint correction model; cooperative regulation and control of cathode inlet temperature and humidity are realized, dynamic change of working conditions is adapted, and stable operation of the fuel cell is guaranteed.

The invention relates to a method for preparing a hierarchical porous catalyst layer of a high-drainage porous membrane electrode based on micro-nano bubbles, which comprises the following steps of: generating oxygen bubbles under the catalysis of carbon-loaded platinum by taking hydrogen peroxide as a bubble source, and constructing the high-drainage porous membrane electrode by taking the micro-nano bubbles as a template; the specific method comprises the following steps: dissolving a carbon-supported platinum catalyst PtC and a Nafion solution in ethanol and water to obtain a solution, carrying out ultrasonic treatment on the solution, dropwise coating the solution on carbon paper at 80 DEG C, and dropwise adding a hydrogen peroxide solution in the coating process; and drying in a vacuum freeze drying box after air drying. According to the invention, the membrane electrode with high porosity is constructed, so that liquid water is effectively prevented from blocking pores, and the phenomenon of water logging in the battery is relieved. According to the preparation method, shrinkage and agglomeration of catalyst particles are avoided, and the hierarchical porous catalyst layer of the porous membrane electrode with high drainage performance is obtained. The invention also provides application of the porous membrane electrode in the field of fuel cells.

This invention discloses a pipe expansion joint reinforcement device and its construction method, comprising: two auxiliary pipe fitting assemblies, detachably fitted onto opposite ends of a pipe expansion joint; a support beam assembly, disposed on one side of the pipe expansion joint, the support beam assembly being arranged along the length direction of the pipe expansion joint, the support beam assembly including a first beam segment, a second beam segment, and an elastic element, the first beam segment forming an axially arranged socket channel, one end of the second beam segment slidingly disposed in the socket channel, and the elastic element connecting the first beam segment and the second beam segment; and a quick-connect assembly, the other ends of the first beam segment and the second beam segment respectively connected to the two auxiliary pipe fitting assemblies. This invention solves the problem that the pressure-bearing capacity of existing HDPE pipe expansion joints is relatively weak and prone to disengagement.

The present application relates to a lotus leaf-like biomimetic bipolar plate, a self-draining method thereof and a fuel cell, the lotus leaf-like biomimetic bipolar plate comprising a bipolar plate body, a flow channel ridge, a flow channel, a branch flow channel, a confluence flow channel, a gas inlet and a gas outlet; the flow channel is provided with uniformly distributed micro flow fields; the micro flow field comprises uniformly distributed lotus leaf-like papilla structures. The lotus leaf-like biomimetic bipolar plate is provided with micro flow fields in the flow field and lotus leaf-like papilla structures in the micro flow field, so that the water generated by the reaction cannot be infiltrated in the flow field, but is separated by the lotus leaf-like papilla structures into the form of water droplets and slid out of the bipolar plate, the draining efficiency is improved, and the phenomenon of water flooding of the fuel cell is reduced.

This application relates to the field of proton exchange membrane fuel cell technology, and provides a gas diffusion layer, its preparation method, and its application. The gas diffusion layer includes a substrate layer and a microporous layer disposed on one side of the substrate layer. The substrate layer has stacked carbon fibers with voids between them. The microporous layer permeates into the substrate layer, forming overlapping portions, and partially permeates into the voids formed by the carbon fibers in the substrate layer. The microporous layer has a fluorine content of 12wt% to 25wt%, and the water contact angle difference between the microporous layer and the substrate layer is Δ, where Δ satisfies 0°≤Δ≤5°. This gas diffusion layer not only has good water drainage and permeability, but also, through the stacked arrangement of the substrate layer and the microporous layer, which gives the substrate layer and the microporous layer similar water properties, effectively reduces the condensation of water vapor in the permeate gas within the gas diffusion layer, increases the humidity of the permeate gas, and thus effectively maintains the wettability of the proton exchange membrane fuel cell.