太阳能与浅层地热能联合供暖运行模式分析

文章通过太阳能与浅层地热能联合供暖的必要性,介绍了一种太阳能与浅层地热能联合供暖系统,探讨了联合供暖的运行模式,并对其经济性进行了分析,为综合利用太阳能和浅层地热能提供参考。     

地热能利用浅谈

对地热的现状及利用技术的发展作了分析研究。特别指明用热泵技术可对广泛存在的低温地热加以利用，但要保证设备的技术先进,确保能源利用的投资能源系数合理。     

国外能源公司地热能利用现状以及对中国石化的启示

地热能作为一种无污染、可再生的清洁能源,具有稳定可靠、成本低廉、清洁环保等优点。国外能源公司在地热能利用方面积累了成功的技术和管理经验．其中以冰岛绿源公司为代表的地热供暖、以雪佛龙为代表的地热发电、以壳牌为代表的干热岩发电处于国际领先地位。这些公司都拥有雄厚的资金实力、良好的国际声誉以及完整的产业链;并且都集中优势资源,重点发展某一项地热业务．而后再逐渐向地热能利用的其他领域扩张;同时还具备完善的科研设备和一流的科研人员,注重科技创新。中国石化正在积极扩大地热能研究和利用工作,旗下新星石油公司已发展成为国内常规地热能开发利用的第一大公司。截至2012年底,新星石油公司地热供暖能力达1000×10^4m2,约占全国常规地热供暖面积的25％。今后中国石化应逐步拓展地热能利用范围。延伸地热能利用产业链;加强科研攻关,积极创新,促进地热开发利用关键技术研发及推广应用;同时要加强国际交流与合作,加快地热开发利用技术的制度建设,并积极争取国家、地方的优惠政策和支持,推动我国地热产业快速健康发展。     

油区地热能综合利用方案分析——以福山油田为例*

油田区域地热资源十分丰富,并且存在大量的用热需求。在油田地区综合开发地热能,不仅可以解决油田伴热、社区供暖/制冷等问题,还可以降低环境污染,减少二氧化碳的排放,有利于油田的持续稳定发展。基于海南福山油田的地热资源条件及用能需求,将油田生产伴热、热泵尾水升温和地热驱动吸收式制冷技术相结合,设计了多种油田地热能综合利用方案,并计算比较了各个方案的经济收益,进一步分析了地热水温度和流量对各个方案适用性的影响,研究结果可为其他油田区域地热资源的综合开发利用提供参考。     

地热资源的开发利用及可持续发展

地热资源作为一种新型能源矿产,具有分布广泛、易于开发等特点,其利用方式主要有地热发电和地热直接利用两种.我国具有良好的地热资源条件,主要为中低温地热资源.据计算,我国12个主要沉积盆地的地热可开采资源量为7500×1018J,相当于2560×108t标煤.当前,我国地热资源利用方式主要以供暖、洗浴、种植等直接利用为主;地热发电发展缓慢,主要分布在西藏;利用热泵技术开发地热资源得到了快速发展;油区地热资源的开发利用也取得了良好的经济和社会效益.但同时我国地热资源产业也面临着一些问题,包括大部分地区尚未开展地热资源勘查评价,影响了地热资源规划的制订及地热产业的发展;防腐、防垢技术还需要进一步加强研究;地热回灌率普遍过低;增强型地热系统研究有待加强等.为了促进地热资源的可持续发展,建议在加大地热资源勘查力度的同时,应以浅层地温能和热水型地热资源为主,发挥热泵技术的优势,开展地热资源的综合利用及梯级利用;重视和加快油气区地热资源的利用;在西藏等适宜地区加大高温地热能发电利用;集中全国优势技术力量,在一两个有利区域开展增强型地热系统技术探索;此外,走回灌开发道路是地热资源开发利用的必然选择.     

公共建筑储热式地热供暖系统多目标协同优化

储热技术是解决办公建筑地热供暖系统供需难以良好匹配及提高地热能利用率的有效手段之一,然而储热装置的引入将增加供暖系统的投资与维护成本,在一定程度上使系统发展受限。以位于河北省沧州地区的某办公建筑为研究对象,构建了储热式地热供暖系统模型,以综合成本、地热能利用率与碳排放量为优化目标,对系统设备选型及运行策略开展协同优化设计。研究表明,与基准系统相比,增设储热水箱可以明显改善地热供暖系统的性能;合理地控制储热水箱储、放热与热泵机组运行是降低系统成本与碳排放量、提高地热能利用率的关键。在此基础上,确定了储热式地热供暖系统的最优运行策略以及对应的设备选型优化参数。最优运行策略下相较于基准系统综合成本降低30.24%,日均地热能利用率提高11.12%,碳排放量减少46.65%。     

Importance of geothermal energy and its environmental effects in Turkey

Geothermal energy, a relatively benign energy source when compared with other energy sources due to reduction in greenhouse gas emissions, is used for electricity generation and direct utilization. Turkey has a place among the first seven countries in the world in the abundance of geothermal resources, but it has only used about 4% of its potential. The paper presents the status of energy needs and renewables, potential, utilization and the importance of geothermal energy in Turkey. It also gives a comparison between geothermal energy and other energy sources regarding environmental issues. It is estimated that if the geothermal heating potential alone in Turkey is used, 5 million residences will be heated and as a result, releases of 48 million ton/year CO₂ emissions into the atmosphere will be prevented. In addition to this, if the other geothermal potential (i.e. electricity) is used it will provide considerable environmental benefits. Therefore, it is expected that geothermal energy development will significantly speed up in the future.     

Sustainable geothermal utilization – Case histories; definitions; research issues and modelling

Sustainable development by definition meets the needs of the present without compromising the ability of future generations to meet their own needs. The Earth's enormous geothermal resources have the potential to contribute significantly to sustainable energy use worldwide as well as to help mitigate climate change. Experience from the use of numerous geothermal systems worldwide lasting several decades demonstrates that by maintaining production below a certain limit the systems reach a balance between net energy discharge and recharge that may be maintained for a long time (100–300 years). Modelling studies indicate that the effect of heavy utilization is often reversible on a time-scale comparable to the period of utilization. Thus, geothermal resources can be used in a sustainable manner either through (1) constant production below the sustainable limit, (2) step-wise increase in production, (3) intermittent excessive production with breaks, and (4) reduced production after a shorter period of heavy production. The long production histories that are available for low-temperature as well as high-temperature geothermal systems distributed throughout the world, provide the most valuable data available for studying sustainable management of geothermal resources, and reservoir modelling is the most powerful tool available for this purpose. The paper presents sustainability modelling studies for the Hamar and Nesjavellir geothermal systems in Iceland, the Beijing Urban system in China and the Olkaria system in Kenya as examples. Several relevant research issues have also been identified, such as the relevance of system boundary conditions during long-term utilization, how far reaching interference from utilization is, how effectively geothermal systems recover after heavy utilization and the reliability of long-term (more than 100 years) model predictions.     

地热流体开发利用中防垢除垢技术研究进展

地热流体结垢是阻碍地热资源稳定、经济和高效开发利用的因素之一。系统总结了中高温地热流体开发利用中防垢除垢技术研究进展。中高温地热田中代表性垢物是钙垢和硅垢,其中钙垢成分以CaCO₃为主,多形成于因压力下降导致CO₂脱气的开采井或者地面设备,硅垢成分以无定型SiO₂为主,多形成于因温度下降导致的溶解度减小的回灌井或者地面设备。实际生产中防垢除垢技术应结合地热流体利用方式进行选择和优化,直接利用方式可考虑采用基于CaCO₃和无定型SiO₂热力学性质的防垢技术;发电方式中钙垢可考虑阻垢剂注入的防垢技术,而硅垢则考虑利用石英和无定型SiO₂溶解度差异、调控温度、pH、无定型Si O₂浓度等防垢技术。     

苏州市浅层地热能应用潜力评估与研究

介绍了浅层地热能应用潜力评估的方法,从影响浅层地热能开发的各项因素中确立浅层地热能适宜区分区的关键指标,通过GIS技术实现浅层地热能开发适宜性分区;并对苏州市进行了地埋管换热系统适宜性分区,计算了苏州各行政区浅层地热能单位温差储量和适宜区与较适宜区的总换热功率,为苏州市浅层地热能合理开发利用提供参考依据。。     

从欧洲地热发展看我国地热开发利用问题

近年来,欧洲地热资源的开发利用取得了迅速的发展。我国地热能的开发利用与欧洲相比具有诸多的相似性。因此,欧洲地热利用的发展经验对我国地热开发利用具有重要的借鉴意义。本文介绍了欧洲地热开发利用的现状和趋势,分析总结了欧洲地热利用的发展模式,并针对我国地热的开发现状和存在的问题,提出了促进我国地热利用发展的对策和建议。     

A snapshot of geothermal energy potential and utilization in Turkey

Turkey is one of the countries with significant potential in geothermal energy. It is estimated that if Turkey utilizes all of her geothermal potential, she can meet 14% of her total energy need (heat and electricity) from geothermal sources. Therefore, today geothermal energy is an attractive option in Turkey to replace fossil fuels. Besides, increase in negative effects of fossil fuels on the environment has forced many countries, including Turkey, to use renewable energy sources. Also, Turkey is an energy importing country; more than two-thirds of her energy requirement is supplied by imports. In this context, geothermal energy appears to be one of the most efficient and effective solutions for sustainable energy development and environmental pollution prevention in Turkey. Since geothermal energy will be used more and more in the future, its current potential, usage, and assessment in Turkey is the focus of the present study. The paper not only presents a review of the potential and utilization of the geothermal energy in Turkey but also provides some guidelines for policy makers.     

Exploring public engagement with geothermal energy in southern Italy: A case study

This paper presents the results of an assessment of public views on eventual geothermal energy development in Sicily. The research was carried out under a much wider research project, VIGOR, with the aim to explore the feasibility of geothermal energy utilization in southern Italy. This study has two primary objectives: (1) to explore the views and opinions of local communities regarding the potential of geothermal energy applications; (2) to contribute to the growing literature on public engagement with energy issues. In order to explore public views towards geothermal technologies, we conducted a case study using both qualitative and quantitative methods. Although Italy has enormous geological potential for geothermal energy production, levels of knowledge of this energy source amongst the public are low. The results indicate that the issue is shrouded in uncertainty and that the Sicilian public expresses a diffused lack of trust in decision-making processes. Taken together, these factors are likely to strongly impact eventual further developments in this sector. The results clearly show the need for further societal dialogue supported by a sound communication action strategy as the first stage in a public participation.     

Dual-fluid-hybrid power plant co-powered by low-temperature geothermal water

Three variants of power plants fuelled or co-fuelled by geothermal water have been assessed, with the aim of making the best use of the energy contained in a stream of 80–120 °C geothermal water. Heat-flow calculations for three power plant types, namely an Organic Rankine Cycle (ORC) power plant, a dual-fluid-hybrid power plant and a single-fluid hybrid-fuelled power plant, are presented. The analysis shows the thermodynamic benefits, in terms of the extent of using the thermal energy of low-temperature geothermal water, that arise from utilizing hybrid and dual-fluid-hybrid power plants rather than ORC power plants. The dual-fluid plant optimizes the use of the geothermal water, but the hybrid plant makes the best overall utilization of the energy compared to separate ORC and fuel-fired plants.     

Geothermal energy utilization trends from a technological paradigm perspective

The use of geothermal energy and its associated technologies has been increasing worldwide. However, there has been little paradigmatic research conducted in this area. This paper proposes a systematic methodology to research the development trends for the sustainable development of geothermal energy. A novel data analysis system was created to research the geothermal energy utilization trends, and a technological paradigm theory was adopted to explain the technological changes. A diffusion velocity model was used to simulate and forecast the geothermal power generation development in the diffusion phase. Simulation results showed that the development of installed capacity for geothermal generation had a strong inertia force along with the S-curve. Power generation from geothermal power sources reached a peak in 2008 and is estimated to be saturated by 2030. Geothermal energy technologies in hybrid power systems based on other renewable energy sources look to be more promising in the future.     

Geothermal development in Hungary—country update report 2000–2002

This paper describes the status of geothermal energy utilization—direct use—in Hungary, with emphasis on developments between 2000 and 2002. The level of utilization of geothermal energy in the world increased in this period and geothermal energy was the leading producer, with 70% of the total electricity production, of all the renewable energy sources (wind, solar, geothermal and tidal), followed by wind energy at 28%. The current cost of direct heat use from biomass is 1–5 US¢/kWh, geothermal 0.5–5 US¢/kWh and solar heating 3–20 US¢/kWh. The data relative to direct use in Hungary decreased in this period and the contribution of geothermal energy to the energy balance of Hungary, despite significant proven reserves (with reinjection) of 380 million m³/year, with a heat content of 63.5 PJ/a at ΔT=40 °C, remained very low (0.25%). Despite the fact that geothermal fluids with temperatures at the surface higher than 100 °C are available, no electricity has been generated. As of 31 December 2002, the geothermal capacity utilised in direct applications in Hungary is estimated to be 324.5 MW_t and to produce 2804 TJ/year. Geothermal heat pumps represent about 4.0 MW_t of this installed capacity. The quantity of thermal water produced for direct uses in 2002 was approximately 22 million m³, with an average utilization temperature of 31 °C. The main consumer of geothermal energy is agriculture (68% of the total geothermal heat dedicated to direct uses). The geothermal water is used only in five spas for space heating and sanitary hot water (SHW), although there are 260 spas in the country, and the thermal water produced has an average surface temperature of 68 °C. The total heat capacity installed in the spas is approximately 1250 MW_t; this is not provided by geothermal but could be, i.e., geothermal could provide more than three times the geothermal capacity utilized in direct uses by 31 December 2002 (324.5 MW_t).     

Geothermal energy potentials in the province of Vojvodina from the aspect of the direct energy utilization

The interest in increasing the participation of renewable energy sources (RES) in energy production arises with increasing population and growing demands for energy production and consumption, as well as the fact of the limited fossil fuels reserves. RES in the energy balance of any country has their share of energy, socio-economic and environmental benefits. Investment in energy sector in the RES domain enables Vojvodina Province to reduce energy dependence on the fossil fuel market.From the total RES potential in Vojvodina Province that is 1293 ktoe/year, around 1.7% is located in existing geothermal sources. There are 73 drills with a total capacity of 72.6 MW from which 65 drills are tested positive. Currently, 15 wells are in production, with a total power of 17.7 MW. There are 27 drills that have never been in production and which are perspective, with a total power of 42.8 MW.The aim of this paper is to perform data analysis of direct geothermal energy utilization according to the water temperature and geothermal fluid flow. According to the results of the analysis recommendations for geothermal energy utilization are given within certain sectors: agriculture (aquaculture and greenhouses), heating of the facilities and pools, industrial applications and balneology.     

Prospects of future geothermal energy development

There are three categories of geothermal resources with huge resource bases: the hydrothermal convection system, the hot igneous system, and the regional conductive environment. However, under the present technical and economic condition, high temperature hydrothermal convection is the only commercially attractive resource for electric power generation, On the other hand, increasingly more attention is being paid to nonelectrical uses of moderate temperature geothermal resources.National and regional research efforts should be focused initially on the assessment and development of liquid-dominated hydrothermal resources, in order to establish confidence in geothermal energy as a viable energy option at the earliest possible time. With respect to the utilization problem of liquid-dominated resources, the development of cost-effective systems to use moderate-temperature resources for both electric and nonelectric applications would greatly expand the geothermal energy potential.Removal of the institutional uncertainties and legal barriers and encouragement by means of financial supports are necessary to stimulate the commercial activity of geothermal energy development.     

黑龙江省地热能资源开发利用研究

黑龙江省地热能资源丰富,目前已发现的地热田有松嫩盆地地热田和敦密地堑镜泊湖段地热田。地热能资源开发利用既经济又环保,符合国家节能减排发展低碳经济产业政策要求。黑龙江省地热能资源属可直接利用的中低温地热能类型,可用于冬季采暖、温泉旅游、矿水医疗、生活洗浴、矿水浴盐生产等领域     

Life cycle assessment of geothermal binary power plants using enhanced low-temperature reservoirs

Geothermal binary power plants that use low-temperature heat sources have gained increasing interest in the recent years due to political efforts to reduce greenhouse gas emissions and the consumption of finite energy resources. The construction of such plants requires large amounts of energy and material. Hence, the question arises if geothermal binary power plants are also environmentally promising from a cradle-to-grave point of view. In this context, a comprehensive Life Cycle Analysis (LCA) on geothermal power production from EGS (enhanced geothermal systems) low-temperature reservoirs is performed. The results of the analysis show that the environmental impacts are very much influenced by the geological conditions that can be obtained at a specific site. At sites with (above-) average geological conditions, geothermal binary power generation can significantly contribute to more sustainable power supply. At sites with less favorable conditions, only certain plant designs can make up for the energy and material input to lock up the geothermal reservoir by the provided energy. The main aspects of environmentally sound plants are enhancement of the reservoir productivity, reliable design of the deep wells and an efficient utilization of the geothermal fluid for net power and district heat production.