中深层无干扰地岩热供暖系统测试研究

地热能被誉为面向未来的能源,在我国“双碳战略”背景下其开发利用受到越来越多重视。中深层无干扰地岩热供暖技术具有“封闭换热、对地上地下环境无干扰、自主供热”等特点,近年来已在我国很多地区得到应用。进一步探究该技术在不同地区的应用特点,对中深层无干扰地岩热技术在宁夏地区的首个应用案例进行测试研究。经测试单口中深层无干扰地岩热换热孔平均输出功率为547.9 kW,连续测试四个月期间热源侧平均供水温度变化范围为33.622.7℃,没有明显的下降;经测试数据分析计算,应用案例年运行成本135662.6元,平均运行单价为1.71元/m^(2)·月;相比于燃煤锅炉供暖方式,年可节约费用517937.4万元,运行单价降低6.53元/m^(2)月,降低幅度达79%;同时年可替代标煤116.3 t,年可减少CO_(2)排放量为288.1 t,具有良好的经济和环保效益。

太阳能与中深层无干扰地岩热耦合供热测试研究

为充分发挥太阳能与中深层无干扰地岩热技术的优势,建成太阳能与地热能耦合供热的测试平台。该测试平台由中深层无干扰地岩热系统、平板集热器系统、槽式集热器系统、真空管集热器系统构成。利用测试平台对太阳能与中深层无干扰地岩热耦合供热的应用案例进行测试。结果显示,采用太阳能与中深层无干扰地岩热耦合供热可以减少地岩热主机运行时长。太阳能系统平均供热量占比约为29.2%,太阳能系统平均集热效率达48%,耦合供热系统综合能效比为5.4,相比于中深层无干扰地岩热系统,耦合系统的综合能效提升17.4%,运行成本可降低约10.8%。

基于“双碳”背景的中深层无干扰地岩热建筑供热技术推行难点和对策研究

寻找可再生能源替代碳基能源建筑供热是实现“双碳”目标的途径之一。国家要求在北方地区大力推进中深层无干扰地岩热建筑供热技术,但是推行7年以来,进展缓慢。通过对中深层无干扰地岩热建筑供热技术的优势、应用现状、应用风险、推行难点方面的分析,从资源、环保、成本及政策环境、市场需求进行研究,得出推行中深层无干扰地岩热建筑供热技术风险可控,推行难点有对策可循的结论,从而为推广该技术提供思路。

中深层地岩热技术在宁夏地区的应用展望

中深层地岩热技术是目前地热能开发领域的主要技术之一,也是未来地热能利用的主要方向,具有封闭换热、取热不取水、无排放无干扰、绿色低碳等特点。目前中深层地岩热技术已经在陕西、甘肃、北京、山东、河南等地实现规模化应用,实现供暖面积超过600万m^(2),但在宁夏地区的应用尚处于起步阶段。本文对中深层地岩热技术原理、技术特点及发展趋势进行了论述,并在调研部分典型案例的基础上提出:中深层地岩热技术的推广应用,对于宁夏地区的新型能源体系构建、区域能源结构调整、清洁取暖等具有良支持作用。

宁夏地区中深层无干扰地岩热建筑供暖技术应用分析

在“双碳”目标下,高效开发利用地热能已成为我国能源转型的重要战略途径。为推动宁夏地区中深层无干扰地岩热建筑供暖技术规模化广泛应用,改善能源结构,以宁夏首个示范项目为研究对象,通过对各类建筑供暖技术的优缺点和成本进行对比及具体工程建设和运行的实践研究,论证了该技术的基本原理、关键技术、换热效能具有安全环保、智慧可靠、运行经济、节能高效的优点,适用于宁夏等寒冷及严寒地区。该项目的顺利实施,为今后宁夏及类似地区规模化广泛应用该技术的政策出台、科学研究、标准规范编制及以工程建设运行管理、人才培养、市场开发、降本增效等提供了相应的实践经验支撑和参考价值。

中深层地岩热耦合热泵技术在房建工程中的应用实例分析

介绍了中深层地岩热耦合热泵技术在甘肃张掖某项目中的应用,并与公路房建工程中较常用的超低温空气源热泵技术进行了分析比较。通过两种热源方案的初投资、年运行费用以及碳排放量的计算分析后发现,中深层地岩热耦合热泵技术的初投资明显远高于超低温空气源热泵技术,但年运行费用接近后者的1/2,随着运行年限的增长,这种优势逐渐凸显。从考虑碳排放的角度出发,中深层地岩热泵系统每年可以减少碳排放量2 460.7 t。另外,由于一个取热孔的供热量大约在0.7 MW,仅适用于供暖面积1万m2以上的建筑工程。

西昆仑库地岩组地质特征及形成时代

库地岩组主要分布于塔里木板块西南缘西昆仑中间地块西河休-帕合堡一带，主要为枕状构造的杏仁状玄武岩、粗玄岩。玄武岩SiO2含量为47．39％～53．91％，岩石碱值（A．R）为1．13～1．40，K2O／Na2O为0．01-0．08，里特曼组合指数（σ）为0．54～1．88，Na2O—2〉K2O，镁铁含量为16．89％-21．07％，属钠质高镁、高铁拉斑玄武岩。稀总姓低，略具铕正异常，（La／Yb）N=1．38～2．36．属轻稀土富集刑。稀土分馏不明显，为深源措浆演化产物，是库地蛇绿岩重要组成部分。本次研究存库地岩组玄武岩源产物辉长辉绿岩中首次获得U—Ph锆石年龄为（524．2±2．4）Ma，时代为早寒武世，为库地蛇绿岩形成演化提供了重要时代依据。

中深层地岩热供暖技术在校园工程中的应用研究

校园工程具有“三不供”间歇性供暖的特点,根据校园所在地地热资源赋存情况,采用中深层地岩热智能供暖系统,根据末端需求自动调整供暖模式。现场实测了中深层地热井的温度分布、地温梯度和系统运行情况,结果表明取热段平均地温梯度达到7℃/hm,室内温度18℃以上,运行费低廉,直供状态下甚至低至0.1元/m2·月,效果显著。

太阳能与中深层地岩热多能互补供热技术的探索和研究

太阳能和地热能储量巨大,是具有极大开发应用潜力的低碳、清洁能源;中深层地岩热供热技术取热不取水,属于可开采应用的低品位地热能资源。将太阳能集热系统与中深层地岩热供热系统相结合,利用兰州地区的太阳能资源,设计建设了1套太阳能集热面积为202 m^(2),单口中深层地岩热换热井直径为200mm、深度为2500 m的太阳能与中深层地岩热多能互补供热系统,在连续取热、地温梯度为30℃/km的条件下模拟了该换热井的供热情况及地岩温度恢复情况;然后对该多能互补供热系统的控制系统进行了优化设计,提出了6种运行模式;最后对该多能互补供热系统在采暖季的实际运行情况进行了测试分析。研究结果显示:1)太阳能集热系统的理论全年得热量为133429 kWh,其采暖季得热量占其全年得热量的31.6%;2)中深层地岩热换热井的热影响半径约为8 m,采暖季结束后地岩温度的恢复周期约为120天,可实现中深层地岩热持续供热;3)在采暖季,该多能互补供热系统中的太阳能集热系统的平均日得热量为307 kWh,可以为整个多能互补供热系统提供约11%的热量;4)多能互补供热系统具有6种运行模式,可以根据用户端热负荷的变化情况和日照条件进行自动控制,灵活配置能源,充分发挥2种能源的优点,以达到最低供热成本的目的。

兰州某学校无干扰地岩热供热系统的工程应用分析

工程设计需要根据项目现有的有限资源,以节约造价及选用运行费用较低的系统方案为前提。本文从实际工程出发,介绍了地岩热这种清洁可再生能源的有效应用,并对项目的初投资和后期运行费进行了分析。

海南岛后地台造山-造盆模型:火成岩地球化学制约

海南岛自海西运动晚幕之后进入后地台活化或地洼阶段，并经历了晚海西-印支期挤压（碰撞）造山、地壳隆起和燕山期以来的块断型造山-造盆作用的过程。火成岩研究资料表明，海南岛地区在晚海西-印支运动期间曾形成一个具有加厚陆壳的后地台造山带；燕山晚期开始出现的裂陷作用是在仍有山根（约60km厚的陆壳）存在的条件下造山带拉伸塌陷阶段的产物；岩石圈底层剥离与地壳山根的去除并最终导致了海南及其邻区从大陆型壳体向陆缘扩张带型壳体的转化。

哀牢山造山带南段马邓岩群的发现及其特征

哀牢山造山带 ,从北东至南西可划分为造山带内带、外带及前陆盆地。据以往资料 ,造山带外带至墨江一带即已终止。最近 ,经 1∶5万黄草岭幅区调 ,发现马邓岩群 ,证实该带继续向东南延伸近 2 0 0km ,这一发现对深入探讨哀牢山造山带的形成、演化和时空展布 ,进一步认识墨江 -绿春地区构造环境具有重要意义。

A review of rockburst:Insights from engineering sites to theoretical investigations

Rockburst has perennially posed a formidable challenge to the stability of underground engineering works,particularly under conditions of deep-seated high stress.This paper provides a comprehensive review of recent advancements in on-site research related to rockburst occurrences,covering on-site case analyses,monitoring methodologies,early warning systems,and risk(proneness)evaluation.Initially,the concepts and classifications of rockburst based on on-site understanding were summarized.The influences of structural planes(in various spatial distribution combinations),in-situ stress(particularly magnitude and direction of the principal stress),dynamic disturbances,and excavation profiles on rockburst were thoroughly assessed and discussed through the analysis of published rockburst cases and on-site survey results.Subsequently,a compendium of commonly employed on-site monitoring techniques was outlined,delineating their respective technical attributes.Particular emphasis is accorded to the efficacy of microseismic monitoring technology and its prospective utility in facilitating dynamic rockburst early warning mechanisms.Building upon this foundation,the feasibility of assessing rockburst propensity while considering on-site variables is verified,encompassing the selection and quantitative evaluation of pertinent indicators.Ultimately,a comprehensive synthesis of the paper is presented,alongside the articulation of prospective research goals for the future.

Support design method for deep soft-rock tunnels in non-hydrostatic high in-situ stress field

Due to the long-term plate tectonic movements in southwestern China,the in-situ stress field in deep formations is complex.When passing through deep soft-rock mass under non-hydrostatic high in-situ stress field,tunnels will suffer serious asymmetric deformation.There is no available support design method for tunnels under such a situation in existing studies to clarify the support time and support stiffness.This study first analyzed the mechanical behavior of tunnels in non-hydrostatic in-situ stress field and derived the theoretical equations of the ground squeezing curve(GSC)and ground loosening curve(GLC).Then,based on the convergence confinement theory,the support design method of deep soft-rock tunnels under non-hydrostatic high in-situ stress field was established considering both squeezing and loosening pressures.In addition,this method can provide the clear support time and support stiffness of the second layer of initial support.The proposed design method was applied to the Wanhe tunnel of the China-Laos railway in China.Monitoring data indicated that the optimal support scheme had a good effect on controlling the tunnel deformation in non-hydrostatic high in-situ stress field.Field applications showed that the secondary lining could be constructed properly.

Performance of water-coupled charge blasting under different in-situ stresses

Water-coupled charge blasting is a promising technique to efficiently break rock masses.In this study,numerical models of double boreholes with water-coupled charge are established using LS-DYNA and are calibrated by the tests of rock masses subjected to explosion loads to examine its performance.The crack levels of rock mass induced by water-coupled charge blasting and air-coupled charge blasting are first compared.It is found that water-coupled charge blasting is more appropriate to fracture deep rock mass than air-coupled charge blasting.In addition,the effects of rock properties,water-coupled charge coefficients,and borehole connection angles on the performance of water-coupled charge blasting are investigated.The results show that rock properties and water-coupled charge coefficients can greatly influence the crack and fragmentation levels of rock mass induced by water-coupled charge blasting under uniform and non-uniform in-situ stresses.However,changing borehole-connection angles can only affect crack and fragmentation levels of rock mass under non-uniform in-situ stresses but barely affect those under uniform in-situ stresses.A formula is finally proposed by considering the above-mentioned factors to provide the design suggestion of water-coupled charge blasting to fracture rock mass with different in-situ stresses.

河北涞源木吉村矿田隐爆相角砾岩发育特征及其形成机制

河北涞源木吉村矿田内突出发育的隐爆相角砾岩,是该内生金属矿田的成矿同源岩体——闪长玢岩侵入晚期的产物。其形成和分布主要受成岩期构造控制。根据隐爆相角砾岩的地质发育特征将其分为四类:爆破角砾岩,震碎—震裂角砾岩、流化—侵入角砾岩、热液注入—交代角砾岩。

中朝地台南部下、中寒武统层序地层特征

中朝地台南部下、中寒武统 (风台组—张夏组 )可划分 9个三级层序。除底部的 DS-A层序外 ,其余 8个层序均可与中朝地台大部分地区进行对比。下部的 3个层序 (DS- A～ DS-2 )属 型层序 ,其余为 型层序。研究表明 ,本区的沉积层序除受早古生代全球海平面变化控制之外 。

Laboratory study of fluid viscosity induced ultrasonic velocity dispersion in reservoir sandstones

Ultrasonic velocities of a set of saturated sandstone samples were measured at simulated in-situ pressures in the laboratory.The samples were obtained from the W formation of the WXS Depression and covered low to nearly high porosity and permeability ranges.The brine and four different density oils were used as pore fluids,which provided a good chance to investigate fluid viscosity-induced velocity dispersion.The analysis of experimental observations of velocity dispersion indicates that（1）the Biot model can explain most of the small discrepancy（about 2–3%）between ultrasonic measurements and zero frequency Gassmann predictions for high porosity and permeability samples saturated by all the fluids used in this experiment and is also valid for medium porosity and permeability samples saturated with low viscosity fluids（less than approximately 3 mP·S）and（2）the squirt flow mechanism dominates the low to medium porosity and permeability samples when fluid viscosity increases and produces large velocity dispersions as high as about 8%. The microfracture aspect ratios were also estimated for the reservoir sandstones and applied to calculate the characteristic frequency of the squirt flow model,above which the Gassmann’ s assumptions are violated and the measured high frequency velocities cannot be directly used for Gassmann’s fluid replacement at the exploration seismic frequency band for W formation sandstones.

Prediction of rockburst classification using Random Forest

The method of Random Forest （RF） was used to classify whether rockburst will happen and the intensity of rockburst in the underground rock projects. Some main control factors of rockburst, such as the values of in-situ stresses, uniaxial compressive strength and tensile strength of rock, and the elastic energy index of rock, were selected in the analysis. The traditional indicators were summarized and divided into indexes I and 1I. Random Forest model and criterion were obtained through training 36 sets of rockburst samples which come from underground rock projects in domestic and abroad. Another 10 samples were tested and evaluated with the model. The evaluated results agree well with the practical records. Comparing the results of support vector machine （SVM） method, and artificial neural network （ANN） method with random forest method, the corresponding misjudgment ratios are 10%, 20%, and 0, respectively. The misjudgment ratio using index I is smaller than that using index II. It is suggested that using the index I and RF model can accurately classify rockburst grade.

The Comparison of Contents of Malondialdehyde and Proline in the Area of Karst Area in Northweastern Guangxi Province

[Objective] To select excellent pioneer species of better ecological and economical comprehensive benefits from the common rock hill plants in Karst area in northwestern Guangxi Province.[Method] Determine the contents of malondialdehyde and proline in leaves of 65 strains of plants by thiobarbituric acid method and sultosalicylic acid method,analyze the relevance of the contents of malondialdehyde and proline by mathematics statistics and analyze the 65 kinds of rock hill plants by clustering [Result] The contents of malondialdehyde and proline are 0.005 2-0.038 1 μmol/g.There are comparably significant differences in the contents of malondialdehyde in different plants;The determination of proline contents in plant＇s leaves are 4.347-374.956 μg/ml.There are also significant differences in proline of different leaves of rock hill plants.The contents of malondialdehyde and proline can be used as a reference point in selecting pioneer plants in Karst area.But when we select the pioneer plants,not only the biological characters of the species themselves should be taken into consideration,but also the differences of Karst area environment,ecological and biological benefits and the reasonable distribution of species.[Conclusion] Pistacia chinensis,Zenia insignis,Acacia confusa,Itoa orientalis and Sophora japonica can be used as the first choices of excellent pioneer plants in Karst area in northwestern area which comparably consists with the real situation of afforestation of rock hills and recovery of plants in Guangxi.