本文選題：微型直接甲醇燃料電池　切入點(diǎn)：陽(yáng)極傳質(zhì)　出處：《哈爾濱工業(yè)大學(xué)》2014年博士論文

【摘要】：微型直接甲醇燃料電池（Micro Direct Methanol Fuel Cell，μDMFC）是一種能夠?qū)⒁后w甲醇的化學(xué)能直接轉(zhuǎn)換為電能的裝置。由于μDMFC具有能量密度高、燃料容易儲(chǔ)存以及系統(tǒng)結(jié)構(gòu)簡(jiǎn)單等優(yōu)點(diǎn)，使其成為應(yīng)用在便攜式微小型設(shè)備上最有前景的能源之一。然而，μDMFC還存在甲醇滲透、陽(yáng)極傳質(zhì)效率低、電池組的集成和穩(wěn)定性不高等問(wèn)題，導(dǎo)致電池放電性能較低，難于滿(mǎn)足便攜式應(yīng)用。本文首先針對(duì)主動(dòng)式的μDMFC建立了兩相傳質(zhì)模型，優(yōu)化設(shè)計(jì)了主動(dòng)式陽(yáng)極流場(chǎng)結(jié)構(gòu)；其次，針對(duì)被動(dòng)式μDMFC陽(yáng)極傳質(zhì)，建立了被動(dòng)式μDMFC陽(yáng)極兩相傳質(zhì)模型；最后，提出了一種“4-cell”被動(dòng)式μDMFC單元電池組結(jié)構(gòu)，對(duì)便攜式應(yīng)用開(kāi)發(fā)具有重要的實(shí)際意義。 針對(duì)傳統(tǒng)主動(dòng)式平行流場(chǎng)傳質(zhì)效率低的問(wèn)題，本文提出了多進(jìn)多出型平行流場(chǎng)并進(jìn)行優(yōu)化。利用建立的μDMFC陽(yáng)極傳質(zhì)模型描述了優(yōu)化的陽(yáng)極流場(chǎng)壓力以及流速分布情況，并利用MEMS工藝在硅極板上實(shí)現(xiàn)了相應(yīng)的流場(chǎng)結(jié)構(gòu)。仿真和實(shí)驗(yàn)結(jié)果一致表明，利用方形凸起優(yōu)化的流場(chǎng)結(jié)構(gòu)改進(jìn)效果最佳，較傳統(tǒng)的平行流場(chǎng)性能提高一倍。其次，針對(duì)傳統(tǒng)主動(dòng)式μDMFC甲醇供給濃度較低的問(wèn)題，提出了一種復(fù)合型主動(dòng)式陽(yáng)極流場(chǎng)結(jié)構(gòu)。利用建立的μDMFC陽(yáng)極傳質(zhì)模型描述了陽(yáng)極擴(kuò)散層及催化層內(nèi)甲醇濃度的分布情況，并利用端板和極板的結(jié)合實(shí)現(xiàn)了復(fù)合流場(chǎng)結(jié)構(gòu)。仿真和實(shí)驗(yàn)結(jié)果表明，相比于傳統(tǒng)平行結(jié)構(gòu)流場(chǎng)，復(fù)合型流場(chǎng)結(jié)構(gòu)具有更大的甲醇傳質(zhì)阻力，能夠有效地提高甲醇供給濃度。 針對(duì)被動(dòng)式μDMFC陽(yáng)極自然對(duì)流現(xiàn)象，本文建立了被動(dòng)式μDMFC二維、穩(wěn)態(tài)、非絕熱模型。模型考慮了被動(dòng)式μDMFC陽(yáng)極儲(chǔ)液腔內(nèi)自然對(duì)流效應(yīng)的影響，并且耦合了熱和物質(zhì)傳輸。整個(gè)耦合模型利用有限元方法求解并通過(guò)實(shí)驗(yàn)驗(yàn)證。仿真結(jié)果表明：在豎直放置的條件下，由于陽(yáng)極自然對(duì)流的影響，電池內(nèi)部的溫度從底部到頂部逐漸升高。隨著甲醇濃度的增加，電池的溫度升高，導(dǎo)致儲(chǔ)液腔中的陽(yáng)極自然對(duì)流效應(yīng)增強(qiáng)，在電池內(nèi)部形成更大的溫度分布扭曲及溫差。甲醇滲透率隨著甲醇供給濃度的增加而增大。隨著電流密度的增加，甲醇滲透現(xiàn)象在較低的供給濃度下逐漸增大，，而在較高的供給濃度下顯示出逐漸減小的趨勢(shì)。以上研究結(jié)果更加準(zhǔn)確的分析了被動(dòng)式μDMFC內(nèi)部的傳質(zhì)過(guò)程。 為了驗(yàn)證被動(dòng)式陽(yáng)極自然對(duì)流現(xiàn)象，設(shè)計(jì)制作了被動(dòng)式μDMFC單體電池。并在單體電池基礎(chǔ)上設(shè)計(jì)并制作了一種面向應(yīng)用的“4-cell”被動(dòng)式μDMFC單元電池組，并利用自設(shè)計(jì)的電聯(lián)方法實(shí)現(xiàn)單元電池組之間的串聯(lián)，從而實(shí)現(xiàn)μDMFC的多節(jié)串聯(lián)。這種結(jié)構(gòu)可以大大提高電池組的穩(wěn)定性。通過(guò)對(duì)電池組穩(wěn)態(tài)及動(dòng)態(tài)性能的全面測(cè)試與分析，得到如下結(jié)論：在室溫的環(huán)境下，“4-cell”被動(dòng)式μDMFC單元電池組的最佳甲醇濃度為5mol/L。單元電池組達(dá)到的最大功率為545mW，最大功率密度為29.62mW/cm2；電池組在不同負(fù)載模式下體現(xiàn)出良好的動(dòng)態(tài)響應(yīng)特性和可重復(fù)性，并成功應(yīng)用于驅(qū)動(dòng)電動(dòng)機(jī)以及給手機(jī)充電。
[Abstract]:Micro direct methanol fuel cell (Micro Direct Methanol Fuel Cell, DMFC) is a kind of chemical liquid methanol can be directly converted to electrical energy device. Because the DMFC has high energy density, easy storage and fuel system has the advantages of simple structure and other advantages, make it become one of the most promising applications in portable miniature the device's energy. However, there are still DMFC methanol permeability, mass transfer efficiency of anode is low, the integration and stability of the battery group is not high, resulting in discharge performance of the battery is low, it is difficult to meet portable applications. Firstly, the main dynamic DMFC type a two-phase mass transfer model, the optimization design of the active anode flow field structure secondly, according to the DMFC; passive anode mass transfer, a passive DMFC two-phase mass transfer model; finally, proposed a "4-cell" passive DMFC cell group structure of portable The application and development of the type is of great practical significance.
In view of the traditional active mass transfer parallel flow field the problem of low efficiency, this paper proposed a MIMO type parallel flow field and optimized. Using DMFC anode mass transfer model is established to describe the optimization of anode flow field pressure and velocity distribution, flow structure and the corresponding realization of the silicon plate using the MEMS process. Simulation and experiment the results showed that the best improvement using the flow structure of square protrusion optimization, compared with the traditional parallel flow field performance doubled. Secondly, in view of the traditional active DMFC low concentration methanol supply problems, puts forward a composite type active anode flow field structure. Using DMFC anode mass transfer model is established to describe the distribution of anode diffusion layer and the catalyst layer in the methanol concentration, and the combination of the end plate and the plate realizes the composite flow structure. The simulation and experimental results show that compared to the traditional flat With the structure flow field, the compound flow field structure has greater methanol mass transfer resistance and can effectively improve the methanol supply concentration.
For passive DMFC anode natural convection phenomenon, this paper established the passive DMFC two-dimensional, steady-state, non adiabatic model. The model considers the effect of passive DMFC anode liquid storage cavity effect of natural convection, and coupled heat and mass transfer. The coupling model using finite element method and verified by experiments. The simulation results show that: vertical conditions, due to the influence of natural convection inside the battery anode, the temperature gradually increased from the bottom to the top. With the increase of methanol concentration, the cell temperature increased, resulting in enhanced liquid storage cavity in the anode effect of natural convection, the temperature distribution and thermal distortion is formed larger inside the battery and methanol permeability. With the increase of methanol supply concentration. With the increase of current density, methanol permeation phenomenon gradually increased in supply under low concentration and high concentration in supply The trend of gradual decrease is shown. The above results are more accurate to analyze the mass transfer process in the passive muon DMFC.
In order to verify the natural convection of passive anode phenomena, design of passive DMFC single battery. And in the single cell was designed and fabricated for application "4-cell" passive DMFC cell group, and the use of self designed electrical contact method between the unit batteries in series, so as to realize the series. DMFC multi section. This structure can greatly improve the stability of battery. Through comprehensive test and analysis of the static and dynamic performance of the battery, we get the following conclusions: at room temperature, the maximum power optimal methanol concentration 4-cell DMFC unit passive battery pack for 5mol/L. cell group reached 545mW and the maximum power density was 29.62mW/cm2; the battery shows a good dynamic response characteristic and repeatability in the model under different load, and successfully applied to the drive motor and the mobile phone Charge.

【學(xué)位授予單位】：哈爾濱工業(yè)大學(xué)
【學(xué)位級(jí)別】：博士
【學(xué)位授予年份】：2014
【分類(lèi)號(hào)】：TM911.4

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相關(guān)期刊論文 前3條

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3 ;Silicon-based micro direct methanol fuel cell with an N-inputs-N-outputs anode flow pattern[J];Chinese Science Bulletin;2011年08期

本文編號(hào)：1695285