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为了发展社会主义商品经济.促进技术进步,改进产品质量,提高社会和企业经济效益,维护国家和人民的利益,使标准化工作适应社会主义现代化建设和发展对外经济关系的需要,国家制定了标准化法。以法律的形式确定了标准化工作的地位和重要性,对各行各业、对企业和个人明确了其法律责任,对违法者必予以追究。国家及有关部门制定了各种各样的标准,从而保障了人民生命财产的安全,保护了消费者的利益,保护了环境。使国家资源能合理地利用,科学技术成果得到了推广,提高了经济效益,使许多产品能通用互换,做到了技术上先进,经济上合理,… 相似文献
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科学技术是效率的强大动力。19世纪中叶,出现了热力学、电磁学两门学科,到了19世纪末,造出了发电机和内燃机。进入20世纪,兴起了以电力和内燃机为标志的技术革命。技术革命极大地提高了效率,但却不能推动公平,甚而出现了反公平的势力,导致世界更不公平,最后... 相似文献
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根据YC6108ZQ柴油机的结构特点和工艺性要求,确立了4气门柴油机气门和气道的布置方案,气门尺寸和位置,选定了气道参数,设计了4气门柴油机气缸盖和摇臂机构,重新匹配了燃烧系统与供油系统,开发成功了YC6108ZQ4气门柴油机。发动机台试验结果表明,该4气门柴油机的功率提高了9%,最大转矩提高了12.7%,柴油机的经济性能有较大程度的改善,燃油经济区域的工况范围扩大,最低燃油消耗率降低。开发的4气门柴油机能够满足亚洲I号排放标准的要求,尤其是CO和NOx排放降低效果明显。所开发成功的YC6108ZQ4气门柴油机进气系统,供油系统和燃烧系统等匹配较好,达到了良好的燃烧效果,其动力性,经济性和排放水平达到了较高的水平。 相似文献
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魏守武 《能源技术(上海)》2004,25(2):84-85
真空除氧冷凝系统原采用混合式冷凝器,给系统运行带来许多问题,重新设计计算后,系统改用表面式换热器,不但完全达到了原先要求的工艺指标,而且,停用了新鲜水,回收了蒸汽的余热,改善了工人的劳动条件,取得了较好的经济效益和社会效益。 相似文献
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近年来,综合自动化保护已在变电所中广泛应用,继电保护的运行可靠性有了很大的提高,但在综合自动化保护的设计中,存在一些缺陷,阻碍了供电的可靠性。为此,分析了出现问题的原因,经过大量试验的检验,改进了原设计及接线,并在现场进行了应用。 相似文献
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卷烟厂空调系统节能控制策略的研究及应用 总被引:2,自引:0,他引:2
针对空调系统巨大的节能空间,进行节能控制策略的研究和应用,并对应用效果在理论上进行分析。实际运行结果表明,节能控制策略的应用,满足了工艺的温湿度要求,减少了能源浪费,降低了生产成本,取得了良好的效果。 相似文献
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兖州矿业(集团)公司焦化厂利用剩余的煤气作能源,建立了焦化厂自备电站发电自用,减少了环境污染,降低了生产成本,保护了生态环境,取得了较好的经济效益和社会效益。 相似文献
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Roberto Hernández-Gómez Dirk Tuma Daniel Lozano-Martín César R. Chamorro 《International Journal of Hydrogen Energy》2018,43(49):21983-21998
The GERG-2008 equation of state is the approved ISO standard (ISO 20765-2) for the calculation of thermophysical properties of natural gas mixtures. The composition of natural gas can vary considerably due to the diversity of origin. Further diversification was generated by adding hydrogen, biogas, or other non-conventional energy gases. In this work, high-precision experimental (p, ρ, T) data for two gravimetrically prepared synthetic natural gas mixtures are reported. One mixture resembled a conventional natural gas of 11 components (11 M) with a nominal mixture composition (amount-of-substance fraction) of 0.8845 for methane as the matrix compound with the other compounds being 0.005 for oxygen, 0.04 for nitrogen, 0.015 for carbon dioxide, 0.04 for ethane, 0.01 for propane, 0.002 each for n- and isobutane, and ultimately 0.0005 each for isopentane, n-pentane, and n-hexane. The other mixture was a 13-component hydrogen-enriched natural gas with a low calorific value featuring a nominal composition of 0.7885 for methane, 0.03 for hydrogen, 0.005 for helium, 0.12 for nitrogen, 0.04 for carbon dioxide, 0.0075 for ethane, 0.003 for propane, 0.002 each for n- and isobutane, and 0.0005 each for neopentane, isopentane, n-pentane, and n-hexane. Density measurements were performed in an isothermal operational mode at temperatures between 260 and 350 K and at pressures up to 20 MPa by using a single-sinker densimeter with magnetic suspension coupling. The data were compared with the corresponding densities calculated from both GERG-2008 and AGA8-DC92 equations of state to test their performance on real mixtures. The average absolute deviation from GERG-2008 (AGA8-DC92) is 0.027% (0.078%) for 11 M and 0.095% (0.062%) for the 13-component H2-enriched mixture, respectively. The corresponding maximum relative deviation from GERG-2008 (AGA8-DC92) amounts to 0.095% (0.127%) for 11 M and 0.291% (0.193%) for the H2-enriched mixture. 相似文献
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By using the integral representations for main thermoelastic Green's functions (MTGFs) we prove a theorem about new structural formulas for MTGFs for a whole class of boundary value problems (BVPs) of thermoelasticity for some semi-infinite Cartesian domains. According to these new structural formulas many MTGFs for a plane, a half-plane, a quadrant, a space, a quarter-space and an octant may be obtained by changing the respective well-known GFPE and their regular parts. The crucial moment of our investigation consists of elaboration of a new technique for calculating some generalized integrals containing products of two different GFPEs. Also, the types of boundary conditions for volume dilatation considered and GFPE for temperature differ on a single boundary only. As example of application of the obtained new structural formulas, the new MTGFs for a concrete BVP of thermoelaesticity for an octant are derived in elementary functions. The MTGFs obtained are validated on a known example for a BVP for half-space. Graphical computer evaluation of the derived in elementary functions new MTGFs is included. 相似文献
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预测了西北5省(区)非水电可再生能源的配额量和交易量,建立了配额制下可再生能源电力跨区、跨省交易经济性评价模型和方法,分析了新疆、甘肃和青海等西北可再生能源主要基地跨区、跨省交易送出的主要目标市场,提出了争取可再生能源电力输电补贴、水电比重偏大省份可再生能源发电企业的结算价格采用本省平均购电价格等政策建议。 相似文献
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The present article describes the influence of radiation on two-dimensional laminar magnetohydrodynamic fluid flow passing over a convective surface. The behavior of the thermal equation is explored through Joule heating, heat generation/absorption, and viscous dissipation. The aim of this study is to examine the physical behavior of the entropy optimization rate. The Cartesian coordinates system is used to model the flow equations. Using similarity variables, a system of partial differential equations is converted into a system of ordinary differential equations. The problem is solved using HAM. The influence of various pertinent parameters on fluid characteristics is graphically explored. Velocity decreases for an increased amount of magnetic parameter, suction parameter, and velocity slip parameter, while behaves the opposite for Grashof number. Temperature increases for a large amount for Brinkman number, magnetic parameter, and radiation parameter, while decreases for Prandtl number. Entropy generation rate increases for Brinkman number, magnetic parameter, and temperature difference parameter. Bejan number decreases for Brinkman number while behaves the opposite for magnetic parameter and temperature difference parameter. Skin friction decreases for large values of magnetic parameters while behaving the opposite for a large amount of velocity slip parameter. Nusselt number decreases for a large amount of Brinkman number. For a better understanding of the study, comparison between numerical outcomes of entropy generation rate and Bejan number for different values of Prandtl number has been done through tables. Also, numerical outcomes of skin friction and Nusselt number are discussed using pertinent parameters through tables. 相似文献
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Design modeling of lithium-ion battery performance 总被引:1,自引:0,他引:1
A computer design modeling technique has been developed for lithium-ion batteries to assist in setting goals for cell components, assessing materials requirements, and evaluating thermal management strategies. In this study, the input data for the model included design criteria from Quallion, LLC for Gen-2 18650 cells, which were used to test the accuracy of the dimensional modeling. Performance measurements on these cells were done at the electrochemical analysis and diagnostics laboratory (EADL) at Argonne National Laboratory. The impedance and capacity related criteria were calculated from the EADL measurements. Five batteries were designed for which the number of windings around the cell core was increased for each succeeding battery to study the effect of this variable upon the dimensions, weight, and performance of the batteries. The lumped-parameter battery model values were calculated for these batteries from the laboratory results, with adjustments for the current collection resistance calculated for the individual batteries. 相似文献
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In this paper we analyse the requirements of bioproductive land in a future industrial society of 10 billion people, with an average per capita economic standard comparable to that of the industrialized countries of today. Despite significantly more efficient technology, lowering demand for both energy and material per service delivered, requirement for food and material alone will call for a heavily increased demand for bioproductive land for use in agriculture and forestry. Large areas of short rotation energy plantations may be biophysically possible, but will clearly compete for available bioproductive land with agriculture and silviculture, as well as with preservation of the world's biodiversity. Therefore, the notion that there exists large areas of surplus or degraded land, which, without coming in conflict with food production and preservation of biodiversity, can be used for large energy plantations has not fully taken into account possible increased demand for bioproductive land from global industrialization and the raising of the global average economic standard. 相似文献
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This paper presents the decision support technique and influencing factors in the design of an integrated solar-wind power system for stand-alone applications. Results of investigations on application of alternative energy facility like wind, photovoltaic (PV), and Integration of wind–PV power generating systems for Remote Area Power Supply have been presented. A weather model-based site matching of equipment and a simple numerical algorithm for generation unit sizing have been presented. The program has been used to determine the optimum generation capacity and storage needs for a stand-alone Wind, PV, and integrated wind–PV system for a remote site in India (Sukhalai situated near Suktawa in Hoshangabad district of Madhya Pradesh) that satisfies a typical load. Generation and storage units for each system are properly sized in order to meet the annual load demand for the above three scenarios. Annual average hourly values for load, wind speed, and insolation have been used for analysis. The results are used to justify the use of renewable energy source as a reliable option for remote areas. 相似文献
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This paper addresses the annual energy storage requirements of small islanded electricity systems with wind and photovoltaic (PV) generation, using hourly demand and resource data for a range of locations in New Zealand. Normalised storage capacities with respect to annual demand for six locations with winter-peaking demand profiles were lower for wind generation than for PV generation, with an average PV:wind storage ratio of 1.768:1. For two summer-peaking demand profiles, normalised storage capacities were lower for PV generation, with storage ratios of 0.613:1 and 0.455:1. When the sensitivity of storage was modelled for winter-peaking demand profiles, average storage ratios were reduced. Hybrid wind/PV systems had lower storage capacity requirements than for wind generation alone for two locations. Peak power for storage charging was generally greater with PV generation than with wind generation, and peak charging power increased for the hybrid systems. The results are compared with those for country-scale electricity systems, and measures for minimising storage capacity are discussed. It is proposed that modelling of storage capacity requirements should be included in the design process at the earliest possible stage, and that new policy settings may be required to facilitate a transition to energy storage in fully renewable electricity systems. 相似文献
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The general availability growth models for large scale complicated repairable system such as electric generating units, power station auxiliaries, and transmission and distribution installations are presented. The calculation formulas for the maintenance coefficient, mathematical expressions for general availability growth models, ways for estimating, and fitting on checking the parameters of the model are introduced. Availability growth models for electric generating units, power station auxiliaries, and transmission and distribution installations are given together with verification examples for availability growth models of 320–1000 MW nuclear power units and 1000 MW thermal power units, 200–1000 MW power station auxiliaries, and 220–500 kV transmission and distribution installations. The verification results for operation availability data show that the maintenance coefficients for electric generating units, power station auxiliaries, transmission and distribution installations conform to the power function, and general availability growth models conform to rules of availability growth tendency of power equipment. 相似文献