Comprehensive evaluation of marine waste heat recovery technologies based on Hierarchy-Grey correlation analysis

In this study,comprehensive evaluation of the technologies on waste heat recovery technologies for maritime applications has been carried out.We have focused our research on exhaust gas turbine system(EGT),thermodynamic organic rankine cycle(RC),Kalina cycle(KC)and thermoelectric generators(TG),which are the most appropriate and most up-to-date techniques for recovering power from marine engines.Each technology has its own advantages and disadvantages,so the comprehensive evaluation of these technologies is essential to accurately determine which technology will be applied to which target.This belongs to the multi-criteria decision(MCDM)process.The combined assessment methodology,consisting of gray correlation and analysis hierarchy processes,has been applied to evaluate four waste heat recovery techniques in terms of technical,economic,social and environmental aspects.According to the comparison results,the exhaust gas turbine system has been evaluated as the most promising technology among the various WHR technologies that can be applied to marine engines.Sensitivity analysis suggests that if investment cost of TG falls to about the same level as the one of EGT,TG could be the best method among these technologies.Reduction of investment cost of TG technology could be realized by development of low cost thermoelectric material.We have analyzed the correlation between each cost through DOE analysis and investigate the effect of individual costs on the total cost.This work helps in identifying the most suitable heat recovery technologies for marine engine.

Comprehensive evaluation of multiple cropping systems on upland red soil

According to the principles and methods of ecology and system engineering,we set up an evaluation indicator system for multi-component and multiple crop-ping systems,evaluated the comprehensive benefits of multi-component and multiple cropping systems using grey relation clustering analysis and screened out the optimized model based on research done in the upland red soil in Jiangxi Agricultural University from 1984 to 2004.The results show that the grey relation degree of"cabbage/potato/maize-sesame"was the highest among 23 multi-component and multiple cropping systems and was clustered into the optimized system.This indicates that"cabbage/potato/maize-sesame"can bring the best social,economic and ecological benefits,increase product yield and farmers’income and promote sustainable development of agricultural production.Therefore,it is suitable for promotion on upland red soil.The grey relation degree of"canola/Chinese milk vetch/maize/mung bean/maize"was second,which is suitable for imple-mentation at the city outskirts.In conclusion,these two planting patterns are expected to play important roles in the reconstruction of the planting structure and optimization of the planting patterns on upland red soil.

基于灰色系统理论的天彭牡丹品种综合评价

运用灰色系统理论对15个天彭牡丹品种进行了综合评价。结果表明:‘丹景玉楼’与参考品种的关联度最大(r=0.7547),综合性状最好,其次是‘红晕白’(r=0.7274)、‘绿晕白’(r=0.7149),综合性状优良,而‘醉西施’关联度最小(r=0.5039),表现最差。评价结果与品种的实际表现比较一致,证明在对观赏性状合理确定分值前提下,利用灰色关联度分析方法对天彭牡丹进行性状综合评价是科学可行的。

灰色关联度分析法和DTOPSIS法在道路观赏植物综合评价中的应用比较

将灰色关联度法与DTOPSIS法结合,克服了DTOPSIS法确定权重时主观性和片面性的缺点,并用两种方法对5种道路观赏植物进行了综合评价,结果表明,两种方法综合评价的判断结果基本相同,其中猴樟表现最优。研究认为,DTOPSIS法能将品种的综合性状进行量化,品种间值差异十分明显,而灰色关联度法差异不大。

40个牡丹品种在宜昌地区的观赏价值评价

为促进观赏牡丹在宜昌地区的推广应用,以花王、岛锦、黑豹等40个观赏牡丹品种为试验材料,选取8个性状为评价因子,采用灰色关联度分析法,研究各性状指标对品种总体表现的影响,综合评价品种优劣。结果表明:参试的40个牡丹品种中,岛锦、香玉、彩绘等13个品种与参考品种的关联度较大(r≥0.700 0)具有较好的适应性和观赏性;紫二乔、如花似玉、日暮等13个品种与参考品种关联度一般(0.700 0>r≥0.650 0)适应性和观赏性一般;金晃、群芳殿、鲁菏红等14个品种与参考品种关联度较低(r<0.650 0),适应性和观赏性较差。评价结果与品种的实际表现基本一致,说明在观赏形状分值较合理的前提下,利用灰色关联度分析法对其进行性状综合评价是可行的。