Ultrasupercritical power plant development and high temperature materials applications in China

Abstract

The rapid development of Chinese economy demands sustainable growth of power generation to meet industrial and domestic demand. The total installed capacity of electricity and annual overall electricity generation are now both the second highest in the world, close to those of the USA. Forecasts of China's electricity demand over the period 2010–20 are presented. Chinese power plants, like those worldwide, are facing demands to increase thermal efficiency and to decrease the emission of CO₂, SO_X and NO_X. In light of the national resource of coal and electricity market requirements in the next 15 years, power generation – especially ultrasupercritical (USC) power plants with the steam temperature over 600°C – will undergo rapid development. The first 1000 MW USC power unit, with steam parameters 600°C, 26·25 MPa, entered service in November 2006. It is estimated that more than 350 USC power units will be installed in China by 2020. USC power plant designs will adopt a variety of qualified high temperature materials for boiler and turbine manufacturing applications. Among these materials, the modified 9–12%Cr ferritic steels, Ni–Cr austenitic steels and certain nickel base superalloys have received special attention in the Chinese materials market.     

Experience of surveillance schemes adopted for magnox steel reactor pressure vessels

Abstract

Surveillance or monitoring schemes are recognised to be an important part of any strategy to demonstrate that reactor pressure vessels used in civil nuclear power stations are operated within a safe regime. In the paper the authors describe the experience obtained from the surveillance schemes adopted for the UK's magnox nuclear power stations that were constructed with C–Mn steel reactor pressure vessels. These power stations were constructed in the late 1950s and 1960s and the last ceased generating in 2006. During the lifetime of the fleet with steel pressure vessels, there were developments in testing, observed changes in properties and understanding of radiation damage process that challenged the safety cases to support the operation of the stations. At the time the reactors were designed the concept of fracture toughness was only beginning to be investigated yet, during the lifetime of the stations, fracture toughness testing was successfully adopted as an input to fracture mechanics based assessment of the steel vessels. Over the operating life, a series of challenges emerged that were successfully addressed, including both hardening and non-hardening embrittlement, the latter due to impurity phosphorous segregation in weld metal and contributions from thermal nuclear embrittlement. These challenges led to the adoption of sophisticated statistical techniques to assess changes in embrittlement properties of the most critical construction material – submerged arc weld metal. A large scale sampling and testing programme of submerged arc weld metal removed from a decommissioned reactor pressure vessel validated the assessment process. As a result of successfully addressing these, and other challenges when the last two steel pressure vessel stations closed in December 2006, they had achieved lifetimes of nearly 40 years.     

Effects of fuel composition and temperature on fireside corrosion resistance of materials for advanced ultrasupercritical coal fired power plants

Abstract

The fireside corrosion resistance of candidate materials for the waterwalls and superheater/reheater sections of ultrasupercritical coal fired boilers have been evaluated through field testing as part of a programme cosponsored by the US Department of Energy and the Ohio Coal Development Office. The materials tested include high strength ferritic steels (SAVE12, P92, HCM12A), austenitic stainless steels (Super304H, 347HFG, HR3C), and high nickel alloys (Haynes 230, CCA617, INCONEL 740, HR6W). Protective coatings (weld overlays, diffusion coatings, laser claddings) that may be required to mitigate corrosion were also evaluated. The trials were based on previous laboratory evaluations under synthesised coal ash and flue gas conditions typical of three North American coals at temperatures ranging from 455 to 595°C for waterwall materials, while superheat/reheat materials were tested at 650–870°C. Promising materials from the laboratory tests were assembled on air cooled, retractable corrosion probes for testing in utility boilers. The probes were designed to maintain metal temperatures using multiple zones, ranging from 650 to 870°C. Three utility boilers, equipped with low NO_x burners, were identified that have adequate flue gas temperatures and represent each of the three coal types. New fireside corrosion probe results are presented for mid-western and western coal types, after approximately one year of exposure in the field. Visual examination of samples from the mid-western utility site indicated minimal evidence of significant wall loss for any of the tested materials. Samples removed from the western utility site indicated evidence of wall loss for some tested materials. Further evaluation and quantification of total metal wastage through wall thickness measurements and metallographic examination of subsurface penetration is being undertaken.     

Energy security and hydropower development in Malaysia: The drivers and challenges facing the Sarawak Corridor of Renewable Energy (SCORE)

This article investigates the drivers and challenges associated with the Sarawak Corridor of Renewable Energy in Malaysia, or SCORE, on the island of Borneo. SCORE constitutes a multi-hundred billion dollar infrastructure development plan in Sarawak, one aiming to achieve US$105 billion of investment and to build 20,000 MW of hydroelectric dams along a 320 km corridor crisscrossing 70,000 square kilometers. Based largely on primary data collected through site visits, original field research in Sarawak, and more than eighty research interviews, the article identifies the genesis of SCORE, its expected benefits, and challenges with implementation encountered to date. The article begins by describing its research methods and then summarizes four sets of anticipated benefits discussed by respondents associated with SCORE: industrialization, energy security, equitable development, and spillover effects. It then dives into a longer discussion of the technical, economic, political, legal and regulatory, social, and environmental challenges facing the project. The article concludes by offering implications for those wishing to promote other large-scale, energy infrastructure projects throughout the world.     

Energy for sustainable development in Malaysia: Energy policy and alternative energy

Energy is often known as the catalyst for development. Globally, the per capita consumption of energy is often used as a barometer to measure the level of economic development in a particular country. Realizing the importance of energy as a vital component in economic and social development, the government of Malaysia has been continuously reviewing its energy policy to ensure long-term reliability and security of energy supply. Concentrated efforts are being undertaken to ensure the sustainability of energy resources, both depletable and renewable. The aim of this paper is to describe the various energy policies adopted in Malaysia to ensure long-term reliability and security of energy supply. The role of both, non-renewable and renewable sources of energy in the current Five-Fuel Diversification Strategy energy mix will also be discussed. Apart from that, this paper will also describe the various alternative energy and the implementation of energy efficiency program in Malaysia.     

钢铁厂电力系统的节能型重构研究

钢铁企业一般具有能耗总量大、能源构成复杂和可利用余能多等特点。本文通过解剖不同层面钢铁厂节能的渠道和措施,提出了具有系统性、全面和完整的以电能的形式回收钢铁厂各种余能的节能模式以及对钢铁厂内部电力系统进行重构的方案。研究表明钢铁厂电力系统的节能型重构具有较高的应用价值和广阔的应用前景。     

热电池电极材料的研究现状及展望

锂系热电池因具有激活时间短、放电时间长、高比能量和高比功率等特点成为热电池的主导产品。目前对锂系热电池的研究主要集中在电极材料和电解质上,很少有系统综述锂系热电池电极材料的相关文献。本文着重阐述了锂系热电池的阳极材料和阴极材料(硫化物、氧化物和氯化物)的研究现状,并对其未来的发展方向提出了展望。     

Energy for sustainable development in India: Linkages and strategic direction

In recent times the two major international endorsements of the elements of sustainable development the Millennium Development Goals (MDGs) and the World Summit on Sustainable Development (WSSD), have recognized universal access to energy as an important goal. In India, with a population of over a 1000 million people, it is estimated that a mere 43.5% of the households have access to electricity. The choices that the country makes towards energizing the remaining population will have a significant impact on other Sustainable Development parameters such as agriculture, water, health, and even biodiversity. India has set itself a target, going beyond the MDGs, of energizing all households by the year 2012. In view of the differentiated responsibilities of the various ministries to the Government of India, the strategy for reaching this target may not address itself to the larger development goals.     

Energy demand and carbon emissions under different development scenarios for Shanghai,China

In this paper, Shanghai's CO₂ emissions from 1995 to 2006 were estimated following the IPCC guidelines. The energy demand and CO₂ emissions were also projected until 2020, and the CO₂ mitigation potential of the planned government policies and measures that are not yet implemented but will be enacted or adopted by the end of 2020 in Shanghai were estimated. The results show that Shanghai's total CO₂ emissions in 2006 were 184 million tons of CO₂. During 1995–2006, the annual growth rate of CO₂ emissions in Shanghai was 6.22%. Under a business-as-usual (BAU) scenario, total energy demand in Shanghai will rise to 300 million tons of coal equivalent in 2020, which is 3.91 times that of 2005. Total CO₂ emissions in 2010 and 2020 will reach 290 and 630 million tons, respectively, under the BAU scenario. Under a basic-policy (BP) scenario, total energy demand in Shanghai will be 160 million tons of coal equivalent in 2020, which is 2.06 times that of 2005. Total CO₂ emissions in 2010 and 2020 in Shanghai will be 210 and 330 million tons, respectively, 28% and 48% lower than those of the business-as-usual scenario. The results show that the currently planned energy conservation policies for the future, represented by the basic-policy scenario, have a large CO₂ mitigation potential for Shanghai.     

Energy,economy and development (EED) triangle: Concerns for India

In this paper we discuss issues involving energy security with economic growth and development that brings out (i) the dimension of physical security alternative, (ii) framework for a pan South East Asian platform to support energy security and (iii) requirement of promoting regional energy cooperation and specific energy peace initiatives. Sustaining projected economic growth rate coupled with energy security in future is a concern for all developing countries like India. The energy security of these nations is threatened by the disruption of energy supplies by ongoing energy terrorism and geopolitical conflicts in the region. India's geo-strategic position and increasing energy dependence raises concerns for its energy security. We discuss energy security, examine factors and approaches to attempt the energy security in the light of economic growth and development.     

Energy policies for sustainable livelihoods and sustainable development of poor areas in China

Focusing on the sustainable livelihoods of rural households and regional sustainable development, this research takes Yan’an at the upper reaches of Yellow River and Zhaotong at mid-upper reaches of the Yangtze River as the study areas, extracts the central affecting factors of energy consumption and characteristic indexes of energy zoning based on 1560 rural household questionnaires of 85 villages in 4 counties (districts) and database analysis of socio-economic development, conducts energy zoning for the poor areas in China, and puts forward specific supporting policies for each type of zone. The research finds that (1) the study areas are found to have the following energy consumption characteristics: low per capita energy consumption (merely 1/4 of the national average), with energy consumption for non-production purposes taking up the main part (more than 70%), high proportion of non-commercial energy, i.e. firewood, straw, etc. (more than 45%), low utilization rate of such new energy resources as biogas, solar energy, etc. (lower than 2% in high mountain regions), remarkable differentiation of vertical and horizontal zonality, etc. (2) Physical conditions like temperature and topography, socio-economic factors, i.e. income of rural households, energy endowment, transportation conditions, and institutional factors like policy support are the major affecting factors of energy consumption and characteristic indexes of energy policy zoning. (3) According to the characteristic index evaluation and matrix classification of both the suitability for energy development and types of regional energy endowment, the poor areas in China can be divided into three energy policy-oriented zones, i.e. network-based centralized energy supply zone, diversified energy utilization zone, and new energy utilization zone.     

Global assessment of research and development for algae biofuel production and its potential role for sustainable development in developing countries

The possibility of economically deriving fuel from cultivating algae biomass is an attractive addition to the range of measures to relieve the current reliance on fossil fuels. Algae biofuels avoid some of the previous drawbacks associated with crop-based biofuels as the algae do not compete with food crops. The favourable growing conditions found in many developing countries has led to a great deal of speculation about their potentials for reducing oil imports, stimulating rural economies, and even tackling hunger and poverty. By reviewing the status of this technology we suggest that the large uncertainties make it currently unsuitable as a priority for many developing countries. Using bibliometric and patent data analysis, we indicate that many developing countries lack the human capital to develop their own algae industry or adequately prepare policies to support imported technology. Also, we discuss the potential of modern biotechnology, especially genetic modification (GM) to produce new algal strains that are easier to harvest and yield more oil. Controversy surrounding the use of GM and weak biosafety regulatory system represents a significant challenge to adoption of GM technology in developing countries. A range of policy measures are also suggested to ensure that future progress in algae biofuels can contribute to sustainable development.     

The research and development of the key components for desiccant cooling system

An air conditioning option, that is, desiccant cooling system (DCS) in which alternative energy source, such as solar energy, nature gas and rejected heat, can play their part for the benefit of environment and saving energy is constructed by regenerative dehumidification component combined with heat exchanger (recuperator) and evaporative cooler.The mathematical model of an rotary desiccant wheel that can be used to calculate the performance of stationary or rotary bed and transient or steady state operation is founded by considering many terms. A computer program for this new model has been compiled and some results of computer simulation compared with experimental value, they are good in agreement.The performance of evaporator is estimated by computer. We developed some kinds of evaporator of which the COP is about 1015 to decrease the room temperature and clean the air in drier climates. Using a new kind of chemical refrigerant invented by Zu-She Liu, the air conditioner will be simple in construction and very efficient (COP > 30).     

Energy-efficiency research, development and demonstration : New roles for US states

At least eight states have established energy research, development and demonstration (RD&D) programmes. In contrast to federal and utility energy RD&D, most states emphasize applied research on end-use efficiency and renewable energy. States also try to closely link research and technology deployment, in some cases deliberately blurring the line between the two. The states discussed in this paper spend about US$39 million per year for energy RD&D, or one-fifth of the US Department of Energy (DOE) budget for conservation and renewable energy RD&D. When indexed per capita or per energy dollar, the average rate of state RD&D spending on conservation and renewables is about 65–75% that of the US DOE.     

Studies on sulfur poisoning and development of advanced anodic materials for waste-to-energy fuel cells applications

Biomass is the renewable energy source with the most potential penetration in energy market for its positive environmental and socio-economic consequences: biomass live cycles for energy production is carbon neutral; energy crops promote alternative and productive utilizations of rural sites creating new economic opportunities; bioenergy productions promote local energy independence and global energy security defined as availability of energy resource supply.Different technologies are currently available for energy production from biomass, but a key role is played by fuel cells which have both low environmental impacts and high efficiencies. High temperature fuel cells, such as molten carbonate fuel cells (MCFC), are particularly suitable for bioenergy production because it can be directly fed with biogas: in fact, among its principal constituents, methane can be transformed to hydrogen by internal reforming; carbon dioxide is a safe diluent; carbon monoxide is not a poison, but both a fuel, because it can be discharged at the anode, and a hydrogen supplier, because it can produce hydrogen via the water-gas shift reaction.However, the utilization of biomass derived fuels in MCFC presents different problems not yet solved, such as the poisoning of the anode due to byproducts of biofuel chemical processing. The chemical compound with the major negative effects on cell performances is hydrogen sulfide. It reacts with nickel, the main anodic constituent, forming sulfides and blocking catalytic sites for electrode reactions.The aim of this work is to study the hydrogen sulfide effects on MCFC performances for defining the poisoning mechanisms of conventional nickel-based anode, recommending selection criteria of sulfur-tolerant materials, and selecting advanced anodes for MCFC fed with biogas.     

The case for a new energy research,development and promotion policy for the UK

This paper is a critical assessment of the current balance of efforts towards energy research and development (R&D) and the promotion of low-carbon electricity technologies in the UK. We review the UK's main technological options and their estimated cost ranges in the medium term. We contrast the energy R&D spending with the current and expected future cost of renewable promotion policies and point out the high cost of carbon saving through existing renewable promotion arrangements. We also note that liberalisation of the electricity sector has had significant implications for the landscape of energy R&D in the UK. We argue that there is a need for reappraisal of the soundness and balance of the energy R&D and renewable capacity deployment efforts towards new energy technologies. We suggest that the cost-effectiveness of UK deployment policies needs to be more closely analysed as associated costs are non-trivial and expected to rise. We also make a case for considering increasing the current low level of energy R&D expenditure. Much of energy R&D is a public good and we should consider whether the current organisation of R&D effort is fit for purpose. We argue that it is important to build and maintain the research capability in the UK in order to absorb spillovers of technological progress elsewhere in the world. Against this background, the recent signs that an energy R&D renaissance could be underway are therefore positive and welcome.     

Review on current research of materials,fabrication and application for bipolar plate in proton exchange membrane fuel cell

Bipolar plate (BP) in proton exchange membrane (PEM) fuel cells provides conducting paths for electrons between cells, distributes and blocks the reactant gases, removes waste heat, and provides stack structural integrity. It is a key component to ensure the aforementioned functions while maintaining a low cost of fuel cell stack. This paper presents a comprehensive review about the BP materials (metallic, non-porous graphite and composite materials) and the corresponding fabrication methods, flow field layouts, and PEM fuel cells applications. Among the materials, the metallic BP has attracted high attention in automotive application due to its superior mechanical and physical properties, competitive cost compared with non-porous graphite and composite materials, but the fabrication technology and corrosion resistance are the major concerns for metallic bipolar plates. In recent studies, the protective coatings reported such as the conductive polymer, metal nitride/carbide and noble coatings have become the hot topics. They have been widely applied in different kinds of metallic bipolar plates, and the metal nitride coatings exhibit relatively low corrosion current and moderate interfacial contact resistance in comparison to other coatings. In future, developing excellent corrosion resistance and electrical conductivity coatings or novel metallic materials for bipolar plates will greatly enhance PEM fuel cells application in transportation field.     

Recent progress in structural development and band engineering of perovskites materials for photocatalytic solar hydrogen production: A review

Photocatalytic water splitting for hydrogen production is a promising technology for the conversion of solar light to clean energy. In this perspective, several semiconductors have been under investigation, but they show less efficiency, selectivity and stability for hydrogen production. Recently, perovskites are most demanding due to their exceptional characteristics such as controlled structure and morphology, adjustable band structure, controlled valence state, adjustable oxidation state and visible light response. This review highlights structural classification of perovskites and band engineering for solar energy assisted photocatalytic hydrogen production. In the main stream, overview and fundamentals of perovskite materials for selective solar to hydrogen conversion are presented. The structural modification and band alteration to stimulate quantum efficiency and stability are specifically demonstrated. Photoactivity enhancement through metals, noble metals, non-metals doping, oxygen vacancies and fermi level adjustments are also deliberated. The role of perovskites with binary semiconductors towards hydrogen production has also been discussed. Up conversion effect of doping luminescent agents (Er, Ho, Eu, Nd) for improved photocatalytic activity by band gap narrowing is also deliberated. Various conventional and non-conventional synthesis methods for perovskites including solid-state, hydrothermal, sol-gel, co-precipitation, spray-freeze drying, microwave assisted, spray pyrolysis, low temperature combustion, pulse laser deposition and wet chemical method for enhanced photocatalytic activity are also demonstrated in this work. Finally, the key challenges and future directions for sustainable energy systems are also included.     

Simulation and experimental research on energy conversion efficiency of scroll expander for micro‐Compressed Air Energy Storage system

A scroll expander was applied to the Micro‐Compressed Air Energy Storage system, and its energy conversion efficiency was investigated. In order to study the variation mechanism of the volume, mass, pressure and temperature of the air in different chambers, the mathematical model of the expansion process was developed on the base of the geometric model, mass conservation equation, ideal gas equation and energy conservation equation. Then, the mathematical model was implemented in Matlab, and the simulated energy conversion efficiency defined as the ratio between the output shaft power of the scroll expander and the input compressed air power was obtained. Furthermore, a test system was built in order to validate the mathematical model and study the improvement of the energy conversion efficiency. The prototypes of the scroll expander with different cross‐sectional areas of the intake port or the discharge port were fabricated and tested in the experiments. Results show that the simulated torque and energy conversion efficiency agree well with the experimental results. Also, there is a small deviation between the expansion process and the ideal isentropic process due to the gas leakage, intake and discharge loss. In addition, the air supply pressure and the cross‐sectional area ratio of the discharge port to the intake port are two important parameters for the improvement of the energy conversion efficiency. The experiments show that the energy conversion efficiency varies from 23% to 36% at the air supply pressure of 0.35 to 0.65 MPa, indicating that it is proportional to the air supply pressure. It can also be concluded from the experiments that when the air pressure is higher than 0.45 MPa, the ideal ratio range can be determined as 0.6‐0.8. Copyright © 2013 John Wiley & Sons, Ltd.