Optimum Heat Conductance Distribution for Power Optimization of a Regenerated Closed Brayton Cycle

In this paper, the power output of the cycle is taken as objective for performance optimization of an irreversible regenerated closed Brayton cycle coupled to constant-temperature thermal energy reservoirs in the viewpoint of finite time thermodynamics (FTT) or entropy generation minimization (EGM). The analytical formulae about the relations between power output and pressure ratio are derived with the heat resistance losses in the hot- and cold-side heat exchangers and the regenerator, the irreversible compression and expansion losses in the compressor and turbine, and the pressure drop loss in the piping. The maximum power output optimization is performed by searching the optimum heat conductance distribution corresponding to the optimum power output among the hot- and cold-side heat exchangers and the regenerator for the fixed total heat exchanger inventory. The influence of some design parameters, including the temperature ratio of the heat reservoirs, the total heat exchanger inventory, the efficiencies of the compressor and the turbine, and the pressure recovery coefficient, on the optimum heat conductance distribution and the maximum power output are provided. The power plant design with optimization leads to smaller size including the compressor, turbine, and the hot- and cold-side heat exchangers and the regenerator.     

Relation between mechanochemical dechlorination rate of polyvinyl chloride and mill power consumption

A sample of polyvinyl chloride (PVC) powder was milled with CaO powder in a planetary mill for various mill operational parameters. The milled product consisted of dechlorinated hydrocarbon and water-soluble CaOHCl. The dechlorination rate of PVC was determined by the concentration of Cl⁻ ions measured in solution after dispersing the milled product in water. To evaluate the power consumption during PVC dechlorination, the mill power consumption was measured during each experimental run. In addition, media motion during planetary milling was simulated using the discrete element method (DEM), enabling calculation of the mill power consumption. The power consumption calculated by the DEM simulation compared well with the power consumption measured experimentally. The dechlorination rate correlated well with the specific mill power consumption, regardless of the sample weight. The dechlorination rate of PVC when milled with oyster shells (CaCO₃) was observed to be faster than that of the PVC/CaO system, and oyster shells could be used as a reactant for the treatment of PVC wastes. This work should be useful for the design of a reactor for the dechlorination of PVC. Chemical Feedstock Recycling & Other Innovative Recycling Techniques 6     

核电站气载放射性流出物环境辐射剂量计算

计算大亚湾核电站正常工况下气载放射性流出物对80km的大气环境防护距离内的公众所致辐射剂量。根据大亚湾核电站2001年气载放射性流出物排放量,逐时观测气象数据及相关参数,选用修正的高斯烟羽模型和美国核管会导则1.109的食物链模型,运用美国橡树岭国家实验室编制的AIRDOS-EPA程序,程序经修改后适合于中国核设施的计算。计算得到2001年大亚湾核电站气态放射性流出物对周边80km范围内的公众所致的年均集体剂量为4.722E-3人·希,最大个人有效剂量为1.362E-8希。结果表明,2001年大亚湾核电站正常工况下,气载放射性流出物对周围公众造成的剂量当量远低于国家标准,对周边地区居民健康几乎没有影响。     

基于升流式厌氧污泥床反应器的微生物燃料电池的研究

构建了一种基于升流式厌氧污泥床反应器（UASB）的微生物燃料电池（MFCs）,利用UASB高效去除COD能力及连续进样方式,获得稳定电能输出。考察了水力停留时间、进液方式、电极材料、离子交换膜种类、溶液离子强度等因素对于MFCs性能的影响。实验结果表明：在水力停留时间6h、连续进液、高纯石墨板电极以及均相阳离子交换膜条件下,连续运行3个月,放电功率稳定在145mW／m^2,开路电压0．78V,放电电流最高可达321mA／m^2。     

燃煤砷污染及控制技术研究现状

本文对国内外煤燃烧过程中砷的污染及其控制的研究现状进行了综述。概括了煤燃烧过程中砷的排放对环境产生的危害,分析煤中砷的赋存状态、燃烧过程的转化形态、固砷剂对煤中砷的作用和砷在飞灰中的富集状况,讨论燃前洗煤、燃煤固砷、烟气除尘技术减少煤中砷污染排放的研究现状及可行性;根据洁净煤技术应用现状讨论了动力配煤技术在高砷煤砷污染防治中的积极意义。指出加强对煤中砷的释放、控制理论及实用技术的研究,减少砷污染物排放对环境的污染是今后研究的方向。     

黄岛电厂附近海域热环境容量计算

阐述了热环境容量的内涵,并在潮流数值模型的基础上建立了热扩散模型.利用模型试算法计算了黄岛电厂附近海域的热环境容量和剩余热环境容量,经计算,黄岛电厂附近海域的热环境容量为1 484.10 ℃·m3/s,剩余热环境容量为1 124.52 ℃·m3/s.该结果为电厂设计方案提供环境方面的决策依据.     

辽宁省电力行业CO2减排措施的研究

通过采用调查与统计年鉴数据相结合的方法,计算出辽宁省电力行业CO2排放量,结果表明,辽宁省电力行业的CO2排放量为1．52亿t,占辽宁省CO2总排放量的43．80％。其中,大连电力行业的CO2排放量居辽宁省电力行业第1位,铁岭、抚顺和葫芦岛分别排在2、3、4位。并提出削减辽宁省电力行业CO2排放量的措施     

Muting the Voice of the Local in the Age of the Global: How Communication Practices Compromised Public Participation in India's Allain Dunhangan Environmental Impact Assessment

Public participation is widely lauded as a way to make environmental decisions more democratic, to improve their quality, and to enhance their legitimacy. Scholars and citizens around the world repeatedly complain, however, that public participation frequently serves primarily as a pro forma exercise to defend predetermined decisions rather than as a meaningful opportunity for the affected public to influence decision-making. These critiques persist despite considerable research suggesting ways to improve the quality of public participation. This essay explores this problem by analyzing citizen involvement in the environmental impact assessment (EIA) processes for the Allain Duhangan hydropower project in northern India. It describes how meaningful public involvement was compromised—despite repeated objections by citizens and independent consultants—by four communication practices: (1) failing to provide adequate access to information; (2) predetermining EIA outcomes by controlling the definition of issues (“definitional hegemony”); (3) privileging scientific/technical discourse; (4) utilizing “consultative” forms of communication that promote one-way flows of information rather than more interactive forms that encourage the joint construction of information and values. This study further argues that these practices persist because they serve as acts of power that privilege dominant actors and interests in the larger socio-political context. This analysis thus suggests that altering communication practices that compromise the quality of public participation may require attending to the interaction between communication practices, relations of power, and the larger socio-political context in which public participation takes place.     

The Structuration of Public Participation: Organizing Environmental Control

A growing body of participation literature muses over why current mechanisms of public participation persist when they so often fail; calls for expanding the conceptual boundaries of participation beyond institutional mechanisms, and highlights the role communication, and allied concepts such as discourse and rhetoric, play in participatory processes. Given these diverse calls, environmental public participation can benefit from building a mid-level theoretical terrain. In this essay, I draw upon the sociological tradition of Anthony Giddens’ structuration theory and parallel systems thinking which foreground a structure-action mode of analysis. Through this lens I articulate the basic premises of a structuration model for environmental public participation, pointing especially to issues of agency, which involves ontological security and ontological competence, social systems, and various elements within duality of structure, with an eye toward communication-centered research. This theoretical space further indicates the possibilities of connecting the material realm of action/practice with the symbolic domain of environmental self.