Improved ultrasonic differentiation model for structural coal types based on neural network

In order to solve the difficulty of detailed recognition of subdivisions of structural coal types,a differentiation model that combines BP neural network with an ultrasonic reflection method is proposed.Structural coal types are recognized based on a suitable consideration of ultrasonic speed,an ultrasonic attenuation coefficient,characteristics of ultrasonic transmission and other parameters relating to structural coal types.We have focused on a computational model of ultrasonic speed,attenuation coefficient in coal and differentiation algorithm of structural coal types based on a BP neural network.Experiments demonstrate that the model can distinguish structural coal types effectively.It is important for the improved ultrasonic differentiation model to predict coal and gas outbursts.

Quantitative identification of coal-type gas and oil-type gas in source-mixed gas at the northern margin of Qaidam Basin

The current study tested the gas component and carbon isotopic composition of gas samples from 6 oilgas fields at the northern margin of Qaidam Basin, and established a chart to quantitatively identify the mixing ratio of source-mixed gas. Besides, this research quantitatively investigated the natural gas generated by different types of organic matter. The results show that different ratios of source-mixed gas exist in the 6 oil-gas fields at the northern margin of Qaidam Basin. Among them, Mabei has the highest mixing ratio of coal-type gas, followed by Nanbaxian, Mahai, Lenghu-4, Lenghu-3 and Lenghu-5, with the ratios of coal-type gas 91%, 87%, 83%, 66%, 55% and 36%, respectively. Lenghu-3 and Lenghu-4 oil-gas fields were mainly filled by coal-type gas earlier. For Lenghu-3, the gas was mainly generated from low matured source rocks in lower Jurassic Series of Lengxi sub-sag. For Lenghu-4, the gas was mainly generated from humus-mature source rocks in lower Jurassic Series of the northern slope of Kunteyi sub-sag. Gas in Lenghu-5 was mainly later filled oil-type gas, which was generated from high matured sapropelics in lower Jurassic Series of Kunteyi sub-sag. Earlier filled coal-type gas was the main part of Mahai, Nanbaxian and Mabei oil-gas fields. Gas source of Mahai was mainly generated from high mature humics in lower Jurassic Series of Yibei sub-sag; for Nanbaxian, the gas was mainly generated from high matured humics in middle-lower Jurassic Series of Saishiteng sub-sag; for Mabei, the gas was mainly generated from humus-mature source rocks in middle Jurassic Series of Yuqia sub-sag.

Resource types, formation, distribution and prospects of coal-measure gas

Coal-measure gas is the natural gas generated by coal, carbonaceous shale, and dark shale in coal-measure strata. It includes resources of continuous-type coalbed methane (CBM), shale gas and tight gas reservoirs, and trap-type coal-bearing gas reservoirs. Huge in resources, it is an important gas source in the natural gas industry. The formation and distribution characteristics of coal-measure gas in San Juan, Surat, West Siberia and Ordos basins are introduced in this paper. By reviewing the progress of exploration and development of coal-measure gas around the world, the coal-measure gas is confirmed as an important strategic option for gas supply. This understanding is mainly manifested in three aspects. First, globally, the Eurasian east-west coal-accumulation belt and North American north-south coal-accumulation belt are two major coal-accumulation areas in the world, and the Late Carboniferous–Permian, Jurassic and end of Late Cretaceous–Neogene are 3 main coal-accumulation periods. Second, continuous-type and trap-type are two main accumulation modes of coal-measure gas;it is proposed that the area with gas generation intensity of greater than 10×10^8 m^3/km^2 is essential for the formation of large coal-measure gas field, and the CBM generated by medium- to high-rank coal is usually enriched in syncline, while CBM generated by low-rank coal is likely to accumulate when the source rock and caprock are in good configuration. Third, it is predicted that coal-measure gas around the world has huge remaining resources, coal-measure gas outside source is concentrated in Central Asia-Russia, the United States, Canada and other countries/regions, while CBM inside source is largely concentrated in 12 countries. The production of coal-measure gas in China is expected to exceed 1000×10^8 m^3 by 2030, including (500–550)×10^8 m^3 conventional coal-measure gas,(400–450)×10^8 m^3 coal-measure tight gas, and (150–200)×10^8 m^3 CBM.

A study on the genetic relations between Permian Longtan Formation coal series strata and Carlin-type gold deposits,southwestern Guizhou Province,China

A large number of the Carlin-type gold deposits occur in the Longtan Formation in southwestern Guizhou Province.The Long-tan Formation contains abundant basalt,tuff and siliceous rocks.All rocks of the Longtan Formation are enriched in gold,which were deposited in a limited platform environment in the transition zone from marine to continental.The process of sedimentation was accompanied by the eruption of Emeishan basalt and hydrothermal deposition controlled by co-sedimentary submarine deep faults in the west,which led to the formation of a peculiar gold-bearing formation with coal series strata.This formation controlled the occurrence of the Carlin-type gold deposits in southwestern Guizhou Province.In response to the remobilization of the Emei mantle plume during the Yanshanian period,As,Au and other ore-forming materials were continuously extracted by deeply circulating waters from the Emeishan basalt and coal seams,thereafter forming ore-forming hydrothermal solutions.When these elements were transported in the coal seams,large amounts of As,Au and other elements were enriched in pyrite within the coal seams,thus forming high-As coal and Carlin-type gold deposits in the Longtan Formation coal series strata.

Double-directional control bolt support technology and engineering application at large span Y-type intersections in deep coal mines

Under deep and complex geological conditions,severe deformation occurs at intersection points of Y-type roadways with large cross sections during engineering projects in coal mines,especially at junction arches.Based on in-situ investigations and theoretical studies,we have summarized typical forms of destruction and identified high stress and unrestricted support at both sides of junction arch as its main causes.In this study,we also presented double-directional control bolt support technology for a large Y-type span intersection,applied to deep intersection engineering in the Jiahe Coal Mine,which has proved effective.

宽高比对煤柱型冲击地压影响规律的实验研究

我国深部煤炭开采日趋复杂,区段煤柱在采动、构造或坚硬顶底板影响下极易诱发煤柱型冲击地压,煤柱型冲击地压的防治已成为煤矿安全高效开采的难题,研究不同宽高比条件下区段煤柱的力学性能及冲击破坏特性对煤柱型冲击地压防治具有积极意义。采用不同宽高比煤样的“岩-煤-岩”组合体进行了单轴压缩实验,通过分析煤岩组合体的冲击倾向性、动态破坏特征、分形维数和声发射特征参数等,研究了宽高比对煤柱冲击破坏的影响规律。结果发现:①煤柱的宽高比对煤岩组合体的冲击倾向性具有显著影响,宽高比不小于2∶1时,其冲击能量指数K_(E)为1.82~2.65,冲击倾向性无明显变化;小于2∶1时冲击倾向性呈先升高后降低的趋势,1∶1时K_(E)最大,达到了15.43。②随宽高比减小,煤岩组合体破坏特征依次表现为:拉压破坏—压剪破坏—拉剪破坏。煤柱宽高比为5∶1~3∶1时,煤岩组合体破坏较为缓慢;宽高比为2∶1时开始出现片状煤屑弹出,冲击破坏剧烈程度较低;宽高比为1∶1和0.75∶1时,具有明显的冲击破坏特性;宽高比为0.5∶1时,煤岩组合体整体稳定性下降,相对0.75∶1煤岩组合体煤柱破坏的剧烈程度降低。③峰后声发射能量释放率与分形维数D变化规律相似,均随宽高比减小呈先升高后降低的趋势。宽高比不小于2∶1时,煤岩组合体破坏过程中能量持续释放时间较长,煤柱破坏平缓;宽高比为1∶1时,能量释放率和D值明显增大,相较宽高比不小于2∶1煤岩组合体的能量释放率增大了约4倍,D值增大了0.18~0.23,煤柱冲击破坏最为剧烈;宽高比0.75∶1煤岩组合体能量释放率与D值分别降低了约10%和0.01,破坏剧烈程度与1∶1煤岩组合体相近;宽高比减小至0.5∶1时,相关参数的降低幅度约为0.75∶1煤岩组合体的6倍,破坏剧烈程度相对较小。研究表明:宽高比对煤柱的冲击破坏具有显著影响,整体上,煤柱冲击破坏剧烈程度随宽高比减小(5∶1~0.5∶1)呈先升高后逐渐降低的趋势;煤柱宽高比大于3∶1时,煤柱冲击危险性相对较小,煤柱宽高比为1∶1和0.75∶1时冲击危险性较大,0.5∶1次之。

以煤矸石为原料制备P型沸石微粉的研究

基于煤矸石利用率较低的现状和煤矸石富含硅铝成分的特征,提出了将煤矸石废弃物制备成沸石分子筛矿物微粉的思路。以七台河市煤矸石为原材料,采用碱融-水热法合成P型沸石分子筛微粉末,探讨了陈化温度、液固比、碱固比等反应条件对P型分子筛形貌的影响,获得最佳工艺条件为:硅铝比为1∶1,陈化温度为50℃,液固比为7∶1,碱固比为0.8∶1。SEM测试结果显示,合成产物的微观形貌为粒径6μm左右的球形沸石分子筛。XRD测试结果表明,产物特征峰与NaP型分子筛标准特征峰相吻合。

缓倾斜煤层坚硬顶板断层活化微震时空演化规律及诱冲机制

以宽沟缓倾斜煤层I010203工作面为研究背景,结合理论分析、数值模拟等手段对工作面过断层的位移场、应力场变化规律进行了研究,并根据现场监测数据,得到以下结论:(1)根据超前支承压力理论计算与现场实测,将采煤工作面过断层分为3个开采区域,正常开采区域、超前影响区域与断层影响区域,工作面推进过程中微震能量变化由“低频次、高能量”→“低频次、低能量”→“高频次、高能量”;(2)受I010203工作面倾斜角度的影响,工作面运输巷微震能量事件多于工作面回风巷,同时根据采煤工作面微震能量事件分析,在采掘扰动作用下工作面极易发生两种冲击类型事故,断层活化型冲击和断层煤柱型冲击;(3)当采煤工作面距断层较远时,构造应力在采掘扰动作用下释放,微震总能量相对活跃,应力表现为应力显现阶段,随着工作面逐渐推进至断层,微震总能量由稳定阶段转变为活跃阶段,同时断层活化显现由蓄能阶段转变为断层活化阶段;(4)分析宽沟I010203采煤工作面数值模拟结果得到,工作面逐渐向断层推进过程中,其断层接触面由初始活化阶段转变为活化稳定阶段,最终接近断层时表现为活化加剧阶段,其与采煤工作面期间微震大能量事件变化规律基本吻合。

渤海湾盆地东濮凹陷天然气成因及分布特征

针对东濮凹陷高热演化程度区天然气成因复杂,天然气富集规律及勘探潜力认识不清等问题,文中利用聚类分析、生烃模拟实验等手段,对天然气成因类型及分布特征进行了研究。研究结果表明:东濮凹陷存在油型气、煤成气及混合气3大类天然气。其中:油型气包括低熟油型气(Ro介于0.5%~1.2%)、中熟油型气(Ro介于1.2%~1.6%)和高熟油型气(Ro介于1.6%~2.0%),依次分布于构造顶部、斜坡带、洼陷带;煤成气Ro介于2.0%~3.0%,包括源外高熟煤成气和源内高熟煤成气;而混合气主要分布在高热演化烃源灶的大断裂周围。通过对主力生气区分析发现,油型气和煤成气对应的烃源岩主力生气深度分别介于4000~5000,5000~7000 m,空间上具有接力特征。东濮凹陷天然气富集程度与生烃洼陷的热演化程度关系密切,中、高热演化洼陷(Ro介于1.0%~3.0%)将是渤海湾盆地和东濮凹陷未来天然气勘探的重点领域。

胀锁型锚索双向加固窄煤柱试验研究与工程应用

针对沿空掘巷窄煤柱非对称变形问题,提出了对穿锚索双向加固窄煤柱技术,设计了伸长型和胀锁型两种对穿锚索结构及工艺,开展了对穿锚索拉拔试验,试验表明两种锚索结构均满足抗拉要求,从锚索破坏形态、施工便捷性和材料经济性等方面对比分析,确定胀锁型对穿锚索为窄煤柱双向加固的首选。进一步通过相似模型试验与数值模拟研究了不同加固方式下煤柱承载变形规律和对穿锚索受力特征。结果表明:双排紧密型对穿锚索加固试件较未加固试件峰值荷载提高了96.04%,且随着锚索排数及数量的增加,窄煤柱双向加固稳定性越来越高,胀锁型对穿锚索提高了煤柱破坏前的能量储存量和临界破坏点。最后,在济宁三号煤矿123_(下)04工作面运输巷开展胀锁式对穿锚索加固窄煤柱工程试验,监测显示对穿锚索锚固力超过220 kN,锚索加固区煤柱帮鼓量降低70%,窄煤柱整体稳定性好,窄煤柱双向加固技术可行,为沿空掘巷工程提供了新技术途径。

鄂尔多斯盆地东缘山西组煤系页岩孔隙结构特征及其演化规律研究

目的为了解煤系页岩中孔隙结构特征及其演化规律,方法采用X射线衍射、岩石热解、扫描电镜、低压CO_(2)/N_(2)吸附和高压压汞等实验,对鄂尔多斯盆地东缘山西组煤系页岩不同岩相孔隙结构进行表征,分析成岩作用对各岩相孔隙演化的影响。结果结果表明,山西组主要发育富硅泥质页岩岩相(A-1)、泥质/硅质混合页岩岩相(M-2)和富黏土硅质页岩岩相(S-3);介孔是储层孔容的主要来源,贡献度达65%以上,微孔是储层比表面积的主要来源,贡献度达62%以上;S-3页岩总孔容和总比表面积均较大,均值分别为0.0362 cm^(3)/g,35.15 cm^(2)/g,A-1页岩总孔容和总比表面积均较小,均值分别为0.0266 cm^(3)/g,21.39 cm^(2)/g;有机质通过控制微孔发育对页岩比表面积起控制作用,另外,黏土矿物对页岩比表面积有一定促进作用,黄铁矿对M-2页岩和S-3页岩孔隙结构均有一定促进作用;A-1页岩孔隙演化受压实作用、黏土矿物转化作用最为明显,S-3页岩孔隙受胶结作用、有机质生烃作用和溶蚀作用影响均较显著,M-2页岩孔隙兼具A-1和S-3页岩的成岩演化特点。结论研究结果可为鄂尔多斯盆地煤系页岩孔隙结构研究提供借鉴与参考。

致密砂岩气藏与页岩气藏展布模式

在阐述美国和中国致密砂岩气和页岩气资源潜力和年产量的基础上,系统梳理致密砂岩气藏与页岩气藏展布的研究沿革,分析页岩气藏、致密砂岩气藏展布特征及致密砂岩气成因类型。研究表明:(1)美国致密砂岩气在天然气总产量中占比由2008年的35%降至2023年的8%左右;美国页岩气2023年产量为8310×10^(8)m^(3),在天然气总产量中占比由2000—2008年的5%~17%升至2023年的70%以上。(2)中国致密砂岩气占天然气总产量比例由2010年的16%升至2023年的28%以上;2012年中国开始生产页岩气,2023年产量达250×10^(8)m^(3),约占天然气全国总产量的11%。(3)页岩气藏展布模式为连续型,根据页岩气藏是否有断层切割及断距与气层厚度的关系,连续型页岩气藏可分为连续式和断续式两种。(4)与以往大部分学者认为致密砂岩气藏展布模式为连续型的认识不同,致密砂岩气藏展布模式不是连续型;根据圈闭类型,致密砂岩气藏可分为岩性型、背斜型和向斜型3种。(5)中国3大克拉通盆地和埃及Obavied次盆的致密砂岩气为煤成气,美国阿巴拉契亚盆地和阿曼迦巴盐盆地的致密砂岩气为油型气。

榆神府矿区遗留房式煤柱稳定性研究

榆神府矿区大量房式煤柱遗留井下,存在煤柱尺寸偏小引发局部矿震现象。基于上河煤矿房柱式开采具体工程实际,采用理论分析、相似材料模拟实验和FLAC^(3D)计算机数值模拟分析了遗留房式煤柱稳定性状况,结果表明,遗留房式煤柱承受的上覆岩层载荷理论计算数值远小于其单轴极限抗压强度,不会出现压裂破坏;相似材料模拟实验显示遗留房式煤柱未发生宏观破坏和垮落现象,上覆地表下沉量微小;计算机数值模拟得出房式煤柱两帮虽出现微观上剪切破坏,但中部存在较大范围弹性核,不会出现整体塑性破断;因此,上河煤矿当前遗留房式煤柱整体保持稳定状态。如果煤柱与煤房尺寸反向设计开采,房式煤柱将发生明显的塑性破坏和变形,发生失稳并引发矿震现象。研究方法为榆林地区类似生产煤矿探求遗留房式煤柱的稳定性问题具有一定的借鉴意义。

塔里木盆地西南山前坳陷恰探1井二叠系天然气成因和来源

近期,塔里木盆地西南山前坳陷恰探1井在西天山冲断带二叠系碳酸盐岩地层取得了天然气勘探的重大突破,标志着塔西南山前地区一个全新勘探层系的发现。然而,该区存在多套烃源岩,且具有异常复杂的沉积和构造特征,对于恰探1井天然气成因及来源的研究十分薄弱,制约了其下一步天然气的勘探部署。为此,基于区域地质背景、天然气地球化学特征、潜在烃源岩特征等系统开展了恰探1井天然气成因及其来源研究。实测结果表明,恰探1井天然气以甲烷为主(83.53%),气体干燥系数(C_(1)/C_(1-5))为0.992,具有较高含量的N_(2)(8.36%)、CO_(2)(7.28%)和He(0.110%)。天然气中甲烷、乙烷、丙烷和CO_(2)的碳同位素值分别为-27.8‰、-20.2‰、-18.4‰、1.7‰。基于天然气组分、烷烃碳/氢同位素组成等综合判识认为,恰探1井天然气为高—过成熟阶段的煤型气。结合潜在烃源岩的分布、有机质丰度、类型、热成熟度特征认为,该井天然气主要来源于二叠系棋盘组烃源岩,可能还混入了少量碳同位素组成更重的无机烃类气体。另外,N_(2)、CO_(2)等非烃气体及He同位素证据均表明恰探1井天然气有一定比例的无机气体混入,幔源氦比例约占14.6%,其氦含量已达到富氦天然气(He≥0.100%)标准。

神府区块深部煤储层力学特性及裂缝扩展机制

【目的】明确煤力学性质和地应力的分布特征及其对人工裂缝形态和扩展行为的控制机制,对深部煤层压裂设计、井网部署和煤层气资源开发至关重要。【方法】以鄂尔多斯盆地东缘北部神府区块太原组8+9号煤为研究对象,基于声波测井、密度测井、注入/压降试井和排采资料,系统分析煤层及其顶底板岩层的力学性质和地应力分布特征,揭示力学性质和地应力对水力裂缝的控制机理。【结果和结论】结果表明:(1)8+9号煤层与顶底板形成了泥岩−煤−泥岩(占77.4%)、砂岩−煤−泥岩(15.5%)等6种组合。(2)基于声波和密度测井计算的力学参数显示,煤弹性模量在4.83~13.69 GPa(平均6.28 GPa),泊松比0.31~0.41(平均0.37),区域上南北脆性高,中部塑性高。(3)注入/压降试井计算结果显示,研究区最大水平主应力介于31.11~39.11 MPa,最小水平主应力变化范围为25.78~29.94 MPa;声波测井计算结果显示,垂向应力(平均49.12 MPa)>最大水平主应力(平均39.50 MPa)>最小水平主应力(平均33.80 MPa),煤层与顶底板最小水平主应力差在0~12.75 MPa。(4)Abaqus和Fracpro PT模拟结果显示,煤弹性模量越大,裂缝高度相对越大,当顶板与煤层的力学强度差较小时防止穿层;煤层水平主应力差增大,容易沿最大水平主应力形成单一裂缝;煤层水平主应力较顶底板水平主应力越小,易在煤层内形成较长、较低、较宽的裂缝,且不易穿层。研究认为实施较大的压裂规模、缝内暂堵技术和控制裂缝净压力等手段是提高神府区块8+9号煤水力压裂效果的主要途径。

华北地区煤系地层油气资源研究现状及启示

石炭系—二叠系是华北地区重要的含煤层系,发育煤层气、煤系页岩气、煤系致密砂岩气、煤成油等多种油气资源,大量的研究和勘探结果表明煤系地层具有良好的勘探前景。与鄂尔多斯盆地相比,济阳-临清地区石炭系—二叠系煤系地层勘探和研究程度相对较低,在系统总结华北地区煤系地层油气资源类型与富集条件研究现状的基础上,对比分析济阳-临清地区与鄂尔多斯盆地煤系地层的成藏条件,提出济阳-临清地区煤系地层勘探方向。研究结果表明:华北地区煤系地层主要为太原组和山西组,形成于陆表海-三角洲沉积环境中,旋回性强且发育共生的煤层气藏、煤系页岩气藏和煤系致密砂岩气藏。高有机碳含量的煤岩、碳质泥岩、暗色泥岩是形成煤系地层油气资源的物质基础,富氢煤系烃源岩发育区具有一定的煤成油藏勘探潜力,保存条件是煤层气、煤系页岩气富集的关键要素,沉积与成岩作用导致的高孔渗带是煤系致密砂岩气的甜点区。济阳-临清地区具有良好的煤系气和一定的煤成油勘探前景,将一套岩性组合作为勘探对象开展系统评价是提升煤系地层勘探效益的重要技术途径,惠民凹陷与东营凹陷南坡、车镇凹陷西部和孤北潜山太原组是有利的勘探目标。

河南西部某煤田地质特征研究

在当前形势下,实现煤炭资源的保障,要立足国内供给,加大煤矿资源潜力评价和地质勘查,挖掘自身潜力,利用自身优势,寻找新的后续矿源。以某煤炭区域地质情况为背景,研究了煤田沉积环境特征、测井响应特征、煤层分布特征、煤层物理性质、煤岩特征以及煤类。研究得出,某煤炭区可采煤层为赋存在山西组下部的二1煤层,煤层厚度0.15~10.57 m,平均厚4.11 m,属大部分可采的中厚煤层、结构简单,二1煤层为中灰、中硫、高热值贫煤和无烟煤,区内二1煤层的稳定程度属较稳定煤层。研究对该地区煤炭工业发展具有一定的指导意义。

Linde type F(K)沸石对Ni^(2+)的吸附性能及效果

利用粉煤灰合成Linde type F(K)沸石吸附重金属Ni2+,探讨吸附剂用量、初始pH、反应温度以及反应时间对Ni2+吸附效果的影响,同时进行吸附等温线和吸附动力学的数据模拟。结果表明,沸石投加量、初始pH以及反应温度均对Ni2+的去除效果影响明显。随着沸石投加量的不断增大,Ni2+去除率不断提高,饱和吸附量逐渐减小。初始pH 7是沸石吸附Ni2+的最适pH。反应温度越高,沸石吸附Ni2+达到平衡的时间越短。沸石对Ni2+的吸附过程符合Langmuir吸附等温式;准一级动力学方程能较好地描述沸石对Ni2+的吸附行为。

地震诱发煤矿次生灾害类型与评估方法

为解决煤矿承灾体受地震灾害影响易发生次生灾害风险的问题,首先,调查和分析典型案例,归纳总结煤矿次生灾害类型与破坏特征,并基于人、机、环、管全要素,构建地震诱发煤矿次生灾害风险评估三级指标体系;然后,提出风险等级和隐患重要度评估方法;最后,以河北省某市煤矿为例开展实际应用。结果表明:地震诱发煤矿次生灾害类型按照承灾体分为6类;地震诱发煤矿次生灾害发生可能性评估主要考虑煤矿所在区域地震灾害等级、煤矿次生灾害危险性、煤层瓦斯赋存致灾性、矿井水文地质条件致灾性、承灾体设防水平、防灾减灾能力6方面,后果严重性评估主要考虑灾害可能造成的伤亡人数和经济损失2方面;该市煤矿抗震设防薄弱环节为通风系统、井筒支护系统、排水系统,应有针对性地提高抗震设防等级。

碳中和目标下新一代超高参数煤电机组技术体系

该文围绕“双碳”目标,分析煤电对支撑我国新型电力系统的重要作用以及燃煤发电技术的主要发展方向,提出下一代超超临界燃煤发电技术体系,并简要介绍相关研发实践。该技术体系基于国产化的HT700系列高温合金材料,耦合高参数煤电、煤电灵活性、烟气污染物低温氧化吸附(cold oxidation adsorption process,COAP与COAP+)脱除近零排放技术、碳补集、利用与封存技术(carboncapture,utilization and storage,CCUS)、数字化智能化及燃煤耦合多源固废发电等前沿技术,建议开发新一代超高参数燃煤发电机组,实现机组煤耗与能耗水平、运行稳定性、灵活性的有机统一,支撑我国“双碳”目标的实现。