川藏公路工程病害减灾决策支持系统

川藏公路工程病害减灾决策支持系统以地理信息系统、遥感和数据库为技术支撑,以灾害数据库和环境背景数据库为基础,其核心是建立灾害分析模型,以辅助决策部门制定科学合理的减灾规划。系统今后的目标是建立川藏公路数字减灾系统。     

CARR ATWS缓解系统设计

为保证事故工况下反应堆的安全,CARR除设置保护系统外,还设置了ATWS缓解系统。本文介绍了CARR ATWS缓解系统的功能与组成以及技术特点,系统采用数字化技术,并进行了试验验证,其可靠性达到了CARR工程应用的要求。     

Effects of stochastic energy prices on long-term energy-economic scenarios

In view of the currently observed energy prices, recent price scenarios, which have been very moderate until 2004, also tend to favor high future energy prices. Having a large impact on energy-economic scenarios, we incorporate uncertain energy prices into an energy systems model by including a stochastic risk function. Energy systems models are frequently used to aid scenario analysis in energy-related studies. The impact of uncertain energy prices on the supply structures and the interaction with measures in the demand sectors is the focus of the present paper.

For the illustration of the methodological approach, scenarios for four EU countries are presented. Including the stochastic risk function, elements of high energy price scenarios can be found in scenarios with a moderate future development of energy prices. In contrast to scenarios with stochastic investment costs for a limited number of technologies, the inclusion of stochastic energy prices directly affects all parts of the energy system. Robust elements of hedging strategies include increasing utilization of domestic energy carriers, the use of CHP and district heat and the application of additional energy-saving measures in the end-use sectors. Region-specific technology portfolios, i.e., different hedging options, can cause growing energy exchange between the regions in comparison with the deterministic case.     

Domestic futures—Which way to a low-carbon housing stock?

This paper examines various routes to achieving a 60% carbon emission reduction from the UK housing stock by 2050 compared to 1996, using a new object-oriented housing stock and carbon model, DECarb. As housing is at present responsible for 26% of all UK emissions, housing carbon reduction is likely to be a key component for the overall 60% emission reduction target set by the UK Government's Energy White Paper in 2003. This paper compares 3 independently published sets of scenarios detailing possible routes and suggests that highly disaggregated approaches produce more credible data. The results also show that whilst there are many different routes to achieving the target from a technological standpoint, all of them will require significant shifts in current practice. We investigate other routes to achieving this target, while also meeting nearer term reductions of 50% by 2030. DECarb shows that significant challenges exist in meeting these requirements, though they are technically feasible. On this basis it also becomes clear that the domestic sector will not be able to offset smaller reductions from any other sector of the economy.     

An integrated systematic analysis of uncertainties in UK energy transition pathways

Policy goals to transition national energy systems to meet decarbonisation and security goals must contend with multiple overlapping uncertainties. These uncertainties are pervasive through the complex nature of the system, the long term consequences of decisions, and in the models and analytical approaches used. These greatly increase the challenges of informing robust decision making. Energy system studies have tended not to address uncertainty in a systematic manner, relying on simple scenario or sensitivity analysis. This paper utilises an innovative UK energy system model, ESME, which characterises multiple uncertainties via probability distributions and propagates these uncertainties to explore trade-offs in cost effective energy transition scenarios. A linked global sensitivity analysis is used to explore the uncertainties that have most impact on the transition. The analysis highlights the strong impact of uncertainty on delivering the required emission reductions, and the need for an appropriate carbon price. Biomass availability, gas prices and nuclear capital costs emerge as critical uncertainties in delivering emission reductions. Further developing this approach for policy requires an iterative process to ensure a complete understanding and representation of different uncertainties in meeting mitigation policy objectives.     

Modelling Australian land use competition and ecosystem services with food price feedbacks at high spatial resolution

In a globalised world, land use change outlooks are influenced by both locally heterogeneous land attributes and world markets. We demonstrate the importance of high resolution land heterogeneity representation in understanding local impacts of future global scenarios with carbon markets and land competition influencing food prices. A methodologically unique Australian continental model is presented with bottom-up parcel scale granularity in land use change, food, carbon, water, and biodiversity ecosystem service supply determination, and partial equilibrium food price impacts of land competition. We show that food price feedbacks produce modest aggregate national land use and ecosystem service supply changes. However, high resolution results show amplified land use change and ecosystem service impact in some places and muted impacts in other areas relative to national averages. We conclude that fine granularity modelling of geographic diversity produces local land use change and ecosystem service impact insights not discernible with other approaches.     

Modelling the mitigation of lean hydrogen deflagrations in a vented cylindrical rig with water fog

The wide flammability range of hydrogen–air mixtures means that the generation and presence of significant quantities of hydrogen in a confined space will always present some likelihood that a deflagration or explosion might occur. Very fine water mist fogs have been suggested as a possible method of mitigating the overpressure rise should a hydrogen–air deflagration occur.     

A review of climate change, mitigation and adaptation

Global climate change is a change in the long-term weather patterns that characterize the regions of the world. Scientists state unequivocally that the earth is warming. Natural climate variability alone cannot explain this trend. Human activities, especially the burning of coal and oil, have warmed the earth by dramatically increasing the concentrations of heat-trapping gases in the atmosphere. The more of these gases humans put into the atmosphere, the more the earth will warm in the decades and centuries ahead. The impacts of warming can already be observed in many places, from rising sea levels to melting snow and ice to changing weather patterns. Climate change is already affecting ecosystems, freshwater supplies, and human health. Although climate change cannot be avoided entirely, the most severe impacts of climate change can be avoided by substantially reducing the amount of heat-trapping gases released into the atmosphere. However, the time available for beginning serious action to avoid severe global consequences is growing short. This paper reviews assessing of such climate change impacts on various components of the ecosystem such as air, water, plants, animals and human beings, with special emphasis on economy. The most daunting problem of global warming is also discussed. This paper, further reviews the mitigation measures, with a special focus on carbon sequestration and clean development mechanism (CDM). The importance of synergy between climate change mitigation and adaptation has been discussed. An overview of the relationship between economy and emissions, including Carbon Tax and Emission Trading and the policies are also presented.     

Assessment of climate change impact on building energy use and mitigation measures in subtropical climates

Likely increase in energy use in air-conditioned office buildings due to climate change in subtropical Hong Kong was estimated for two emissions scenarios. Towards the end of the 21st century (i.e. 2091-2100), the average annual building energy use would be 6.6% and 8.1% more than that in 1979-2008 for low and medium forcing, respectively. Potential mitigation measures concerning the building envelope, internal condition, lighting load density (LLD) and chiller plant were considered. Thermal insulation to the external wall would not be effective to mitigate the expected increase in building energy use due to climate change. Controlling the amount of solar heat gain through the window would be a better option. Lowering the current LLD of 15 W/m² to about 13 W/m² would result in substantial energy savings because of the reduction in electricity consumption for both electric lighting and air-conditioning. As for the chiller plant, the coefficient of performance (COP) should be improved from the current minimum requirement of 4.7 to at least 5.5 to alleviate the impact of climate change. Raising the summer set point temperature (SST) to 25.5 °C or higher would have high energy saving and hence mitigation potential, which could be readily applied to both new and existing buildings.     

Pure hydrogen co-production by membrane technology in an IGCC power plant with carbon capture

The CO₂ capture in Integrated Gasification Combined Cycle (IGCC) plants causes a significant increase of the cost of electricity (COE) and thus determines high CO₂ mitigation cost (cost per ton of avoided CO₂ emissions). In this work the economic sustainability of the co-production of pure hydrogen in addition to the electricity production was assessed by detailed process simulations and a techno-economic analysis. To produce pure hydrogen a Water Gas Shift reactor and a Selexol^® process was combined with H₂ selective palladium membranes. This innovative process section was compared with the more conventional Pressure Swing Adsorption in order to produce amount of pure hydrogen up to 20% of the total hydrogen available in the syngas.Assuming for a base case a hydrogen selling price of 3 €/kg and a palladium membrane cost of 9200 €/m², a cost of electricity (COE) of 64 €/MWh and a mitigation cost of 20 €/ton_CO2 were obtained for 90% captured CO₂ and 10% hydrogen recovery. An increase of the hydrogen recovery up to 20% determines a reduction of the COE and of the mitigation cost to 50 €/MWh and 5 €/ton_CO2, respectively. A sensitivity analysis showed that even a 50% increase of cost of the membrane per unit surface could determine a COE increase of only about 10% and a maximum increase of the mitigation cost of further 5 €/ton_CO2.