Hydrogen is combustible explode easily gas, gaseous Chu Qing fills high pressure put rate fast, normal temperature can be operated, but need provides recipient of high strenth compression. Hydric and atomic diameter has 0.982nm only, may be permeated in metallic stuff or make metallic metamorphism produces hydrogenous fragile phenomenon, corrode compression container to create the risk such as leak and explosion, especially below high-pressured circumstance more apparent. American energy department was cent of Chu Qing bottle 4 kinds 2002:
I bottle is complete metal bottle, compression does not exceed 30MPa;
II, III bottle is composite material twines external use of the courage inside the metal, compression can raise 70MPa;
The bravery inside IV bottle is high polymer material, whole body enhances wrap up of colophony composite material with fiber, only opening place is a metal, IV a lot of lighter than III bottle, gas storage pressure comparatives;
Current, what car of Chinese fuel cell matures quite with hydrogenous bottle is III bottle, manufacturer home includes national rich hydrogen can, in material science and technology, Ketaike; And IV bottle technology is still immature cannot measure produce, basic by foreign manufacturer forestall, like the whole world the biggest IV bottle produces business Hexagon Haikesikang, and the IV of synthesis of cropland of Toyoda Gosei abundant and Korea Iljin bottle, had used car of cell of car of cell of fuel of series of Yu Fengtian Mirai and fuel of contemporary Nexo series respectively.
The production cost of bottle of IV Chu Qing is in 3000~3500 dollar, basically include: Composite material, valve, adjuster, assemble examination, hydric etc, among them the 75% above that the cost of composite material holds totle drilling cost, and the cost of hydric itself is occupied only about 0.5% . The development trend of technology of Chu Qing bottle is light quantify, density of high-pressured force, tall Chu Qing, macrobian life, compare conventional metallic data, high polymer composite material can be in hold identical compression order and degree while, reduce storage tank wall thick, improve capacity and hydrogenous memory efficiency, reduce the cost of specific power consumption in line-haul process. Accordingly, the function of composite material and cost are the key of preparation of gas cylinder of IV Chu Qing.
One
Structure of bottle of IV Chu Qing
Bottle of IV Chu Qing is made by metalloid composite material entirely besides the shell outside metallic bottle valve base.
The internal composition of bottle of graph 1IV Chu Qing
If the graph is shown 1 times, the internal composition of bottle of IV Chu Qing includes the following share:
Bottle wall total ply is 20~30mm about, most of lining and hydric and direct contact is block gas layer, ply is 2~3mm about, it is alkene kind plasticity polymer, cut off since hydric action;
Intermediate layer is thicker compression layer, material is CFRP carbon fiber enhances composite material, form by carbon fiber and epoxy resin, below the premise that assures compression grade, reduce this thickness as far as possible in order to improve Chu Qing efficiency;
The outerest it is exterior covering layer, ply is 2~3mm about, material is GFRP Bo fine enhances composite material, form by fibre glass and epoxy resin.
Because IV bottle shell is colophony entirely, shape easily, its over all dimension is consequently OK the requirement of fuel car design of different manufacturer and model does according to to be adjusted accordingly.
2
Shell shapes craft
The technological process of preparation of Chu Qing bottle is shown 2 times like the graph, first will thermoplastic alkene polymer is made inside bravery, check the surface to whether have the drawback such as drape, dent next, enter fiber to twine working procedure then, stick the solidify after good label, give outside face polishing next, static after pressing test qualification, do final finished product to detect.
Graph technological process of 2 preparation of Chu Qing bottle. Alphabetical correspondence flow is (A) metalloid liner (B) liner is checked (C) fiber is twined (D) is sticky stick label (E) solidify (F) surface polish (G) is static press a test (H) finished product detects
Key working procedure introduces in detail respectively below.
1, the bravery inside rotational moulding
The first process that bottle of IV Chu Qing makes, it is preparation has what hydrogenous vapour lock lies between a gender inside bravery. Craft is shown 3 times like the graph.
Graph 3 rotational moulding shape craft. Alphabetical correspondence flow is (A) mould backfill (B) Shuang Zhouxuan turns (C) is cooling (D) product drawing of patterns
Good melt index high liquidity polyolefin pink expects, load rotational moulding mould, the mould warms up to above of polyolefin melting point, the axis of two different way makes the mould makes rotation and revolution at the same time, pink expects to hollow structure distributings equably inside the mould after fusing, drawing of patterns drops in temperature after shaping, appear for radius even roughly cylinder shape shell.
The advantage of rotational moulding craft is a wall thick even, shape craft is simple, but also put in goods compact sex is low easy the issue that forms blemish, wall of bravery of place less than is large cannot too thin. After shape inside when bravery enters below one working procedure to be twined by carbon fiber, can be caved upcountry by pressure, should fill constant atmospheric pressure to its interior so in order to balance fibrous tension.
2, fiber is twined
The intermediate layer of Chu Qing bottle and the outerest all be by twine craft to make and become. Fiber is twined is one of the most advanced methods that make part of hollow composite material, the storage tank of producible 1~100m3. Carbon fiber enhances colophony to if the graph is shown 4 times,twine working procedure, include winding unit, colophony macerate unit and control unit.
Graph 4 carbon fiber enhance colophony to twine craft
Among them, w is colophony macerate carbon fiber, CF is carbon fiber, EP is epoxy resin, ip is inorganic grain. Carbon fiber dry silk is twined line wearing is circled to go up in many roving, via securing pulley to guide, after sufficient in liquid epoxy resin macerate, the assemble becomes 1cm wide banding fiber loincloth, below the accurate control of the computer, through laying the reciprocate of box axial, cooperate inside the whirl of bravery actuating device, twine fasciculus inside bravery periphery repeatedly, obtain semifinished product canister thereby. Deserve to have mechanical dasher of the fluid chamfer of epoxy resin, assure to have microwave grain of absorbefacient inorganic ferrite can disperse equably, raise hot solidify sex thereby, fresh liquid epoxy resin complements ceaselessly in the meantime. Fiber is in by drawing while molecular catenary edge suffers force direction orientaton, give fiber proper stress beforehand through additional facility before twine, can make fiber inside on bravery twine the position more accurate.
Besides high strenth of composite material itself, shape means is likewise crucial to function influence. Voluble type (two end are twined, helix is twined and band type is twined) , the frequency, direction, combination that twines the width of the belt, span to wait has infinite a variety of likelihoods, must want to rely on CAE computer to assist engineering design.
3, microwave solidify
The focal point that safety performance of shell of bottle of IV Chu Qing assesses, it is the mechanical performance that carbon fiber and fibre glass enhance epoxy resin composite material, include matrix craze, fiber / matrix is taken off stick and fiber ruptures. Fiber enhances epoxy resin to heat up solidify to want a few hours commonly, the thermal diffusion coefficient of fiber and colophony matrix is different, the interface suffers stress concentration or flabby effect more easily, reduce the performance of composite material. Below microwave illuminate condition, solidify time can shorten considerably, reduce the internal stress that the material after solidify remains, increase base material and fibrous interface active force, improve the intensity of composite material and stiffness thereby. Working procedure of microwave illuminate solidify is shown 5 times like the graph.
Graph craft of solidify of 5 microwave illuminate
Coal tub the coal tub axis of two end props up semifinished product canister go up in frame, with constant speed rotates, generate the microwave of 2.1GHz through microwave oscillator, direct illuminate enhances colophony layer to go up to the fiber of semifinished product canister, the wall that adds shrinkage fitting buy in microwave apparently reflection, continue to bring to bear on to enhance colophony layer to go up to fiber next, support microwave heats make epoxy resin solidify, refrigeration obtains high-pressured hydrogen canister later. The time of microwave illuminate enhances the frequency decision that colophony layer ply, fiber wraps by the dimension of product of canister of hydrogen of final high pressure, fiber. To increase strength, can repeat above fiber to twine the measure with microwave solidify for many times, wait for composite material according to needing to adjust oxygen of use carbon fine, Bo fine, annulus deserve to compare, chemical foreword originallies after increasing, place below proper high temperature namely longer, make epoxy resin complete solidify. Because twine time longerly to be able to make colophony wellability becomes poor, the systematic viscosity of on the high side can make bleb hard eduction, the epoxy resin that needs to join small element to measure low viscosity so is allocated, and should make the outerest annulus oxygen viscosity is less than viscosity of oxygen of intermediate layer annulus, in order to facilitate the eduction of in-house gas in solidify process.
4, beforehand macerate craft
Fiber twines craft to include: Wet twine, dry method is twined and half dry method is twined.
Wet twining is fiber macerate hind is twined directly inside on bravery, installation cost is small, need commands pulling force strictly, easy generation is enraged when solidify bubble.
Doing a law to twine is will beforehand dip cloth heats on twister to stick shed position and twine inside on bravery, the content of fluid of the macerate on fiber but gage control, product quality is stable, winding rate is as high as 100~200m/min, but beforehand dip installation cost is big.
Half dry method is twined is fiber macerate hind, immediately beforehand stoving, twine next inside on bravery.
Graph 6 it is dry fiber beforehand macerate craft graph, fiber does silk to pass roller drawing, sufficient in chamfer of liquid epoxy resin macerate, the pace of Kong Chu of many independence small model that goes up to be arranged cheek by jowl through the mould later shapes, in the be heated in the last mould half solidify finalizes the design, next cut is become beforehand macerate cloth.
Graph 6 fiber beforehand macerate craft
Because guide a passageway very narrow, fiber knows antiquated attrition effect, generation nap, can dry fiber, bilge and redundant exterior colophony, make guide passageway block to reduce productivity. Dry fiber and beforehand the fiber of the solidify after macerate can say to weigh respectively, consequently can every epoxy resin that fiber contains measures gage. Its memory condition should notice after macerate fiber preparation is good beforehand, when need is used, will beforehand macerate cloth heats to 140 ℃ above hind, twine again inside on bravery, the solidify condition such as the quantity of contains epoxy resin and need temperature time, can gain better control.
3
Composite material
1, Chu Qing bottle separates stuff with hydric block
Material of the bravery inside Chu Qing bottle is the key that hydrogenous vapour lock lies between security to ensure. Graph 7 contrast the aeriform permeability of material of different high polymer, EVOH ethylene - ethylene mellow copolymer is right oxygen, vapor, carbon dioxide of 3 kinds of gas cut off the gender is head and shoulders above other polymer material.
Graph the aeriform permeability of film of 7 different polymer is compared
Although PVDC gets together,slant chloric ethylene cuts off performance is very superior also, but the minim chlorine as a result of remain meeting and hydric happening reaction, do not suit to be used at the bravery inside the gas storage bottle with hydric and direct contact so. EVOH is ethylene and the copolymer with mellow ethylene, general ethylene content is between 20~45mol% , density is 1.13~1.31g/cm3, melting point is 160~190 ℃ . EVOH holds the machinability of the block temperament that has PVA polyvinyl alcohol and PE polyethylene concurrently, through adding EVOH, make although the bravery inside Chu Qing bottle is bouncy also below microtherm, ensure cut off admirably function.
The gas of EVOH cuts off the gender is tall basically be the hydrogenous key action as a result of tall crystallization sex and hydroxyl. When ethylene content is reduced, gas cuts off the gender increases; When ethylene content is more than 50mol% , block temperament can be damaged badly. Block temperament lifts along with temperature and reduce, when be like temperature to raise 35 ℃ from 20 ℃ , aerobic transmitance increases 3 times much. Be more than in relative humidity 30% when, the hydroxyl in water element and EVOH produces effect, will bring about gas to cut off function drops apparently.
Hydric osmosis can cause two problems:
(1) plastic inside bravery breaks firm inward cave in.
(2) plastic inside bravery material interior happens succumb phenomenon, bubbly even craze. Ⅳ Chu Qing enrages bottle of even special attention the metal is added record the structure between mouth and polymer shell and data sealed, usable graft polymer internally bravery material does modified, if add only the low viscosity EVA-g-MA of 1wt% , can raise the viscosity of EVOH and torque apparently.
IV Chu Qing enrages bottle of medium EVOH, want to issue long-term safety to use in 70MPa, need solves the following problem:
(1) the rudimental hydrogen in colophony brings about colophony to bubble.
(2) hydrogen is fragile make colophony surface forms ungual form craze.
(3) in - bear below the low temperature of 40 ℃ repeatedly the wear of stress load.
(4) block temperament maintains below high-pressured condition.
Current, the whole world is only 3 companies produce EVOH resin, since driving the synthetic technology that gives out EVOH first 1972, japanese coke beautiful company is the manufacturing company with global the biggest crop all the time, its produce brand name to be EVal® , additionally two are company of industry of Japanese synthesis chemistry and Taiwan Changchun petrifaction. 20 thousand tons of EVOH that China consumes every year, count an import basically entirely.
2, carbon fiber enhances material
Hydric be compressed 70Mpa stores in storage tank, need ensures the intensity of main body can bear high pressure, when storage tank medium hydric when be being used up, main body also is reduced as pressure and contract, high-pressured environment and the exhaustion that fill deflate to be able to bring about material repeatedly. Chu Qing bottle uses carbon fiber basically is product of TORAYCA®T1000G of filament of carbon fiber of Dongli excel in, T1100G. T1000G and T1100G are it is raw material with polyacrylonitrile, control the fire technology of fiber structure subtly through accept rice class, realize high strenth and amount of high stretch standard, and have the aid of beforehand the accept rice alloy of composite material of macerate craft preparation. Use as the excel in carbon fiber of storage tank material is had not only impermeable can, and have exceedingly good hear resistance and be able to bear or endure chemical sex, and good dimension stability, intensity and wearability.
Carbon fiber bundle the composition of 10000~50000 root carbon fiber that is 5~8μm by average diameter. The weight of epoxy resin layer and carbon fiber layer compares for 20~30: 70~80. Between framework material with carbon element and sticky mixture, not only physics adds exert oneself, still have chemical bond resultant force, scent a group of things with common features epoxy resin is more adipose a group of things with common features offer higher intensity like double phenolic A epoxy resin. But, tall viscosity can make macerate operates difficulty, and hard even ground macerate is in-house, should adjust so with the epoxy resin with low degree of polymerization or dissolvent the viscosity when macerate, its defect is to must repeat undertake macerate, with the bigger wave motion of shrinkage of adjusting control bulk.
Although high-powered carbon fiber of domestic T800, T1000 is successful already breakthrough lab is relevant preparation technology, but implementation industry is changed still need to wait for technology of many sided form a complete set to undertake develop mainly and be perfectinged from control of raw material, equipment, technology. It is carbon fiber of preparation high strenth does silk not merely especially, produce a high strenth carbon fiber even beforehand dip, complete the step that knits gauze namely. Dong Li is the whole world the biggest carbon fiber produces business, already formed the industrial group that covers catenary of carbon fiber entire industry with the Japanese enterprise such as person of the Supreme Being, 3 water chestnut.
3, annulus oxygen composite material
With Yu Qing the viscosity of the epoxy resin of storage tank is 4000~8000cP in 25 ℃ , diameter of solid grain bead is less than 10~25μm. The outerest fiber enhances colophony layer medium fibre glass thermal conductivity is low, should ensure the equivalent of epoxy resin and solidify agent compares so for 1: 1, and can absorb the inorganic ferrite grain of microwave want to disperse equably, ability makes solidify sufficient, perhaps make after illuminate microwave through heating fiber increases. In the process of solidify of annulus oxygen be heated, can make bate of the bravery inside polyolefin, for structure of the bravery inside protection, should control highest solidify temperature under inside bravery softening point 10 ℃ above.
Below high-pressured action, hydric permeate receive data and diffuse to be in to composite material interface stage by stage, and hydric iteration is filled uninstall form pressure difference, bring about finally inside bravery data yields to be torn off with the interface frothily. Improvement method is clay is added in composite material.
Graph carbon fiber of macerate of 8 annulus oxygen and argillaceous composite material
If the graph is shown 8 times, matrix of epoxy resin of carbon fiber macerate, again with fluctuation two are the argillaceous film of 1nm ply each, issue lamination through condition of high temperature high pressure, after making its model changes heat to shape, preparation becomes a state of half solidify beforehand dip makings, be in finally processing of the solidify after 100~150 ℃ issues those who have 10~30 hour. Among them carbon fiber regards framework as material, epoxy resin regards bind as the agent. The result with sealed bind enhances since argillaceous film, bases is clay, contain a few colophony, ply does not have pinhole equably. Although this composite material is in - after be being exposed 100 times below the low temperature of 196 ℃ , hydrogenous vapour lock lies between function to also be reduced scarcely.
Hydrogen can be complete of industrial catenary homebred change and gain ground change, the ground floor that needs material science is propped up, only relevant research and industrial chemical industry make orderly series connection rise, build from macroscopical craft parameter, to micromechanism index, occupy warehouse system to the one whole a cycle of songs in a traditional opera of macroscopical performance characteristics again, just spend a perspective to rise to from onefold dimension likely multidimensional spend a perspective, discover then and apply more the rule of high-level class. The acknowledge that controls precision to material when us and operation level promoted, nature is capable to adjust product structure and supply according to demand, achieve structure of Chinese the sources of energy optimize, low carbonization and can change continuously, reach the ultimate goal that the sources of energy neutralizes with carbon independently finally.
Origin | " fiber composite material "
