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1.
Advanced technology paths to global climate stability: energy for a greenhouse planet 总被引：6，自引：0，他引：6
Hoffert MI Caldeira K Benford G Criswell DR Green C Herzog H Jain AK Kheshgi HS Lackner KS Lewis JS Lightfoot HD Manheimer W Mankins JC Mauel ME Perkins LJ Schlesinger ME Volk T Wigley TM 《Science (New York, N.Y.)》2002,298(5595):981-987
Stabilizing the carbon dioxide-induced component of climate change is an energy problem. Establishment of a course toward such stabilization will require the development within the coming decades of primary energy sources that do not emit carbon dioxide to the atmosphere, in addition to efforts to reduce end-use energy demand. Mid-century primary power requirements that are free of carbon dioxide emissions could be several times what we now derive from fossil fuels (approximately 10(13) watts), even with improvements in energy efficiency. Here we survey possible future energy sources, evaluated for their capability to supply massive amounts of carbon emission-free energy and for their potential for large-scale commercialization. Possible candidates for primary energy sources include terrestrial solar and wind energy, solar power satellites, biomass, nuclear fission, nuclear fusion, fission-fusion hybrids, and fossil fuels from which carbon has been sequestered. Non-primary power technologies that could contribute to climate stabilization include efficiency improvements, hydrogen production, storage and transport, superconducting global electric grids, and geoengineering. All of these approaches currently have severe deficiencies that limit their ability to stabilize global climate. We conclude that a broad range of intensive research and development is urgently needed to produce technological options that can allow both climate stabilization and economic development. 相似文献
2.
针对风能和太阳能等新能源的间歇性、可变等不稳定性特征,利用风能和太阳能的资源互补特性,将风能和太阳能通过转化、储存、控制等手段,形成稳定的电力输出。研究太阳能光伏发电系统和开关磁阻风力发电系统最大功率跟踪策略, 提出一种适应天气变化较快的基于输出电压控制的最大功率点跟踪算法,结合蓄电池的智能控制策略,实现智能风光动态互补。MATLAB仿真实验验证了该控制方法的可行性和有效性。 相似文献
3.
A basic thermodynamic cycle for the production of mechanical power from materials that may be made to contract forcibly and reversibly is described. The cycle differs from existing mechanical power cycles which generally employ expanding fluid as working substances. A "contraction turbine" operating on this cycle has been devised, which has collagen fiber as its working substance and salt solution as fuel and produces mechanical work directly from chemical free energy. Direct conversion of chemical to mechanical energy is routinely effected in muscle but not in usual man-made engines. 相似文献
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5.
提出一种适用于环境因子检测装置的太阳能和风能混合供电系统的设计,包括能量转换、充电控制和能量存储部分.实现了太阳能与风能的有效利用以及供电和能量存储部分两者之间的自动切换.并对设计方案做了实际性能测试. 相似文献
6.
[目的]为了研究微波辐射对剩余污泥有机物释放特性的影响因素。[方法]选择不同微波功率、作用时间,考察微波辐射对剩余污泥有机物释放的影响。[结果]延长作用时间和增加微波功率的条件有助于剩余污泥中有机物释放,上清液浊度、有机物总量、蛋白质和多糖含量均增大,而Zeta电位和pH均减小。上清液中多糖和蛋白质的含量分别从40、54 mg/L增加到130、170 mg/L,Zeta电位从-11.2 mV降至-5.1 mV,pH从7.80降至7.07。Zeta电位在(700 W,60 s)时最低,为-5.1 mV,pH最低为7.07,Zeta电位与m(蛋白质)/m(多糖)的比值呈正相关,相关性系数为0.54～0.98。[结论]微波辐射有助于剩余污泥的有机物释放。 相似文献
7.
为了降低电网能耗,为其设备优化升级提供指导,以电网主要设备为研究对象,建立了能效综合评估算法。首先分析电网设备能效影响因素,建立设备能效模型,从单类设备综合损耗率与单台设备损耗率严重超标台数率两个方面挖掘能效指标并给出指标计算方法。考虑到各指标对能效影响的重要程度是多方面的,建立递阶层次结构模型,采用层次分析法计算指标的权重值,同时采用模糊综合评价法计算指标的能效量化分值,以克服其模糊性。采用所建立的算法对某电网的主要设备进行能效分析评估,结果表明了该方法的实用性和有效性。 相似文献
8.
E.S. Nadimi V. Blanes-VidalR.N. Jørgensen S. Christensen 《Computers and Electronics in Agriculture》2011,75(2):238-242
The supply of energy to electronics is an imperative constraining factor to be considered during the design process of mobile ad hoc wireless sensor networks (MANETs). This influence is especially important when the MANET is deployed unattended or the wireless modules within the MANET are not easily accessible. Therefore, exploring novel sources of energy generation rather than operating electronics only on limited power supplies such as batteries is a major challenge. Monitoring free-ranging animal behavior is an application in which the entities (animals) within the MANET are not readily accessible; however, animal movement can be potentially used to generate energy. In this study, the head movements of individual sheep in a flock during grazing were monitored in order to investigate the amount of energy that can be generated by these movements. By applying the Lagrange-d’Alembert Principle to this problem, the equations of motion from each neck-mounted sensor as well as the amount of mechanical energy generated per time instant (each second) during upward and downward head movements were calculated. This resulted in the production of 857 mW and 1660 mW during the downward and upward movements, respectively. Furthermore, the energy consumption of each wireless node within the MANET was estimated to be 117.8 mW per second. Conversion of energy from mechanical to electrical requires miniature electromechanical generators that can currently provide between 25% and 50% conversion efficiency. Even using the worst conversion efficiency (25%), a minimum of 214 ± 25 mW of electrical energy per second could be generated. This amount exceeds the energy consumed by the wireless sensors that can be used to gather parameters describing animal behavior such as neck and head movement. This study suggests that the amount of energy generated by the vertical neck-head movement of sheep during grazing can be converted to useful electrical power adequate to provide power for operation of wireless sensor nodes on a continuous basis within a MANET-based animal behavior monitoring system. 相似文献
9.
Reverse electrodialysis allows for the capture of energy from salinity gradients between salt and fresh waters, but potential applications are currently limited to coastal areas and the need for a large number of membrane pairs. Using salt solutions that could be continuously regenerated with waste heat (≥40°C) and conventional technologies would allow much wider applications of salinity-gradient power production. We used reverse electrodialysis ion-exchange membrane stacks in microbial reverse-electrodialysis cells to efficiently capture salinity-gradient energy from ammonium bicarbonate salt solutions. The maximum power density using acetate reached 5.6 watts per square meter of cathode surface area, which was five times that produced without the dialysis stack, and 3.0 ± 0.05 watts per square meter with domestic wastewater. Maximum energy recovery with acetate reached 30 ± 0.5%. 相似文献
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传统工频定速电机在管道输量较低时,既浪费电能,又缩短了输油泵机组的维护周期和使用寿命。针对该问题,提出了对泵机组采用变频调速改造的方法进行节能控制。输油泵节能原理：保持离心泵输送流量不变,减小离心泵扬程。以某实际运行长输管道为例,详细介绍了高压变频改造项目在长输管道输油泵机组上的节能测试过程,对比分析了输油泵机组加装变频装置前后的节能效果。结果表明：加装变频装置后,节流率、功率因数和机组效率均满足评价标准SY/T 6275-2007限定值和节能评价值的要求,管道2008-2009年度节省电费304.5×104元。 相似文献
11.
集成能量投入-产出分析和灰色关联分析方法,分析1961-2005年我国农业生态系统的能量投入-产出及能效率的变化,找出影响其变化的主导因素.结果表明:能量投入以畜力、有机肥和化肥为主,农业机械能和农业劳动力能比重小;随着能量投入的增加,单位耕地面积上的能量产出在波动中增长,1970年以来高于世界平均水平,但能效率在波动中下降.能效率与农业劳动力能和畜力能等传统动力能的关联性强,有机肥能投入减少对能效率的下降影响较大,化肥能的大量投入对总能量产出的贡献有限.因地制宜地增加机械能、提高有机肥能比重,有助于提高能效率. 相似文献
12.
Popp M 《Science (New York, N.Y.)》1982,218(4579):1280-1285
After more than 25 years of development of nuclear power and almost 10 years of research and development in numerous areas of nonnuclear energy, there is now a good basis for judging the future prospects of energy technologies in the Federal Republic of Germany. The development of nuclear power has provided an important and economically advantageous new source of energy. Further efforts are needed to establish the nuclear fuel cycle in all stages and to exploit the potential of advanced reactors. In all other areas of energy technology, including energy conservation, new energy sources, and coal, economics has turned out to be the key problem, even at today's energy prices. Opportunities to overcome these economic problems through additional R & D are limited. There is some potential for special applications, and there are many technologies that could contribute to the energy supply of developing countries. In general, however, progress in energy conservation and the use of renewable energy sources will depend on the degree to which energy policy measures can improve their economic basis. For some technologies, such as solar thermal power stations and coal liquefaction, large-scale economic deployment cannot be foreseen today. Instead of establishing costly demonstration projects, emphasis will be put on improving key components of these technologies with the aim of having the most advanced technology available when the economic parameters are more favorable. 相似文献
13.
The solar thermal energy stored in hydroelectric reservoir thermoclines is very large and greatly exceeds the gravitational hydroenergy of the surface water, even after limitations arising from the second law of thermodynamics have been taken into account. Greatly enhanced power production can be obtained at present hydroelectric facilities if heat engines are adapted to exploit this large thermal energy resource. 相似文献
14.
从风电价格、区域发展和产业结构调整等方面对江苏风电发展的经济效应进行了评价。结果表明,大力发展风电对江苏具有重要意义,可以节约经济成本,增强企业竞争力;通过建设沿海绿色能源基地,可以缩小区域经济差距;利用风电较长产业链,可以优化产业结构。 相似文献
15.
A 12-day series of 1749 profiles of turbulent kinetic energy dissipation above the equatorial undercurrent at 140 degrees west showed that, in the upper 110 meters of the ocean, the dissipation radically decreased during the solar heating period each day. Daily averages were linearly related to the local wind power. When integrated over the depth range of 10 to 110 meters, the dissipation was 10.6 ergs per square centimeter per second or 0.92 +/- 0.10 percent of the wind power, a proportion not substantially different from those found in mid-latitude surface mixed layers. These results suggest that much of the energy dissipated above the equatorial undercurrent may be extracted directly from the local wind. 相似文献
16.
结合IPCC推荐的参考方法和部门方法,对基于能源平衡表的黑龙江省二氧化碳排放核算方法进行研究。研究结果表明:从总量来看,2000~2010年黑龙江省碳排放总量大体呈现上升趋势;从细分部门来看,碳排放总量最大的是火电部门,其次是工业部门;从细分能源来看,以原煤消费为主的能源需求是导致碳排放总量居高不下的原因。最后提出短期内黑龙江省节能减排应从提高能源效率、重点开展火电部门及工业重点行业的节能减排入手。 相似文献
17.
刘巽浩 《中国农业大学学报》1982,(1):47-54
一个特定的农田生态系统有其一定的能量转换与物质循环的特点与效率。从宏观上对这方面的问题进行研究将有助于从一个侧面探讨农业战略上的一些重大问题。例如,我国农业走什么路子,是有机农业还是无机农业?是强调还是不强调能量的投入?重点将能量投放到高产地区还是低产地区?是重中原还是重边疆?等等。对于这些问题,认识上是有分歧的。为了探讨上述问题并为制定我国农业发展战略服务,我们在近年内先后实地考察了代表 相似文献
18.
Giacoletto LJ 《Science (New York, N.Y.)》1959,130(3380):915-916
Energy storage has long been a problem in connection with home utilization of solar energy. A solution which utilizes solar semiconductor cells for conversion to d-c power is proposed. The d-c power is used to drive an alternator which is connected directly across the residential power lines. Thus a-c power is delivered to the power lines when a surplus of power is available in the home and is used in other parts of the power distribution system. At latitude 42 degrees N there is 3 times more yearly energy recoverable than is used by an average residence on the basis of a 10-by-10-m collection area. At the present state of technical development the cost of such a large-area semiconductor solar cell would be prohibitive. 相似文献
19.
By utilizing the vapor pressure difference between high-salinity and lowsalinity wvater, one can obtain power from the gradients of salinity. This scheme eliminates the major problems associated with conversion methods in which membranes are used. The method we tested gave higher conversion efficiencies than membrane methods. Furthermore, hardware and techniques being developed for ocean thermal energy conversion may be applied to this approach to salinity gradient energy conversion. 相似文献
20.
Kiviat FE 《Science (New York, N.Y.)》1976,194(4266):719-720
An electrochemical concentration cell is proposed as a means of extracting the energy released from the mixing of freshwater with seawater. In order to obtain the maximum power from such a cell, a small amount of seawater must be added to the freshwater prior to its introduction into the cell in order to lower the internal resistance of the cell. The work available from the electrochemical concentration cell is of the same order of magnitude as the work derived from the use of an osmotic pump to extract energy from seawater. Both of these saline water techniques should be considered when unconventional, long-range power sources are evaluated. 相似文献