Control strategy of a fuel-cell power module for electric forklift

Fuel cell-battery hybrid systems for the powertrain, which have the advantage of emission-free power generation and adapt to material transport and emission reduction, are investigated. Based on the characteristics of the fuel cell system and the characteristics of the electric forklift truck powertrain system, this work defines the design principle of the control strategy to improve overall performance and economy. A simulation platform for fuel cell and electric vehicles has been established. The optimal performance of the fuel cell stack and the battery capacity were defined for the specific application. An energy control strategy was defined for different operating cycles and operating conditions. Model validation involved comparing simulation results with experimental data obtained during VDI60 test protocol. The main parameters that influence the forklift performance were defined and evaluated, such as energy loss, fuel cell operating conditions and different battery charging cycles. The optimal size of the fuel cell stack of 11 kW and the battery of 10 Ah was determined for the specific load profile with the proposed control strategy. The results obtained in this work forms the basis for an in-depth study of the energy management of fuel cell battery drive trains for forklift trucks.     

Cow preference and usage of free stalls compared with an open pack area

Free-stall housing systems are designed to provide a comfortable and hygienic lying area, but some aspects of stall design may restrict usage by cows. The aim of this study was to compare free-stall housing with a comparable lying area (open pack) without stall partitions. We predicted that cows would spend more time lying down and standing in the bedded area when provided access to an open pack than when in free stalls. We also predicted that cows would spend less time standing outside of the lying area and less time perching with the front 2 hooves in the lying area when using the open pack. Groups (n = 8) of 12 cows each were provided access to either the open pack or stalls. After a 7-d adaptation period, each group was tested sequentially in the 2 treatments for 3 d each. This no-choice phase was followed by an 8-d choice phase during which cows had simultaneous access to both treatments. During the no-choice phase, cows spent more time lying down (13.03 ± 0.24 vs. 12.48 ± 0.24 h/d) and standing with all 4 hooves in the bedded area (0.96 ± 0.12 vs. 0.41 ± 0.12 h/d) of the open pack than in the stalls. During the choice phase, cows spent more time lying down (7.20 ± 0.29 vs. 5.86 ± 0.29 h/d) and standing with all 4 hooves in the bedded area (0.58 ± 0.07 vs. 0.12 ± 0.07 h/d) of the open pack than in the stalls. In both the no-choice (1.66 ± 0.24 vs. 0.55 ± 0.24 h/d) and choice (0.55 ± 0.07 vs. 0.29 ± 0.07 h/d) phases, cows spent more time standing with just 2 hooves in the stalls than in the open pack. In conclusion, cows spent more time lying and standing with all 4 hooves in the bedded open pack than in the stalls. Additionally, cows spent more time standing in the alley and standing with just the front 2 hooves on the bedding in the stalls than in the bedded open pack; increased standing time on wet concrete is a known risk factor for lameness.     

涩北气田纤维复合高压充填无筛管防砂技术研究与应用

涩北气田是我国第四大气田,其储层为第四系粉砂岩和泥质粉砂岩。这些岩石胶结疏松,出砂严重,气水层间互,防砂难度极大,属世界性难题。研究了纤维复合高压充填无筛管防细粉砂技术系统――储层预处理技术(使用带正电支链的软纤维吸附细粉砂颗粒成颗粒集合体来稳砂)、纤维复合体技术(纤维-树脂砂三维网状复合体挡砂)和高压充填技术(不压开地层充填纤维化合物在水泥环外形成类筛管,达到无筛管防砂目的,并解除近井带损害和增加泄气面积)。该技术可达到防砂和增产双重目的,在涩北气田涩7- 1 - 4井应用取得很好的效果,不出砂产量平均增产到原来的2 .1倍。介绍了纤维复合高压充填无筛管防细粉砂技术的理论、实验、施工设计和现场应用。     

压裂充填井产能预测的分析方法

在压裂充填井表皮因子的组成基础上,提出了压裂充填井产能预测的拟表皮系数分析方法,该方法考虑了裂缝伤害、环空砾石和射孔砾石充填对井产能的影响。运用新模型进行了实例计算和分析,结果表明该模型可满足工程需要。瓶颈裂缝可引起井产能急剧下降,压裂液滤失也对井动态有一定的负面影响。     

基于仿人撕理的自动分切理牌机

设计了一种自动分切理牌机,将原压痕与人工分理工序合为一体,提出扑克牌分理按纸张横向刻痕,纵向分条,有序叠成一条,再次序撕理成付工艺,突破了传统机型。采用电磁吸力作纸张90°转向的正压力,观察人工撕理扑克牌纸张受力状态,设计纸张受扭拉共同作用机构,纸张叠条撕理成副。提高了生产效率。图7参10     

基于滑动平均的锂电池关键参量检测方法研究

针对机载锂电池应用中的安全保障问题,提出了一种基于滑动平均的关键过程参量检测新方法。该方法通过滑动平均处理,实现对机载锂电池应用过程中的安全实时检测。实验结果表明,该方法能够实现对机载锂电池关键参量20 ms循环周期实时检测,单体电压检测精度高于1‰FS,总电压检测精度高于5‰FS,加热与放电电流检测精度高于5‰FS,实时保护时间为50 ms。提出的关键参量实时检测方法具有较高的稳定性,能够有效保证锂电池组应用中的可靠性,该方法的提出能够对锂电池组的安全使用提供技术和方法参考。     

Development of novel diffusion coatings for 9–12 % Cr ferritic‐martensitic steels

Eventhough 9–12% Cr steels are mechanically designed for power plant applications up to 650 °C, their effective use is limited by the corrosion resistance at this temperature. Therefore, the present paper addresses the development of diffusion coatings on 9% Cr ferritic‐martensitic steels. The difficulty of coating these materials with conventional diffusion processes arises from the temperature limit above which the conversion of the martensite is accelerated and the mechanical properties would be deteriorated. Aluminide coatings consisting of Fe₂Al₅ or FeAl phases were thus developed for deposition temperatures between 650 and 715 °C by the conventional pack cementation technique. As the addition of boron was expected to improve the oxidation properties of the coating, the influence of B on the aluminide coating was investigated. The precedent diffusion of Cr as an interdiffusion barrier before switching to the Al diffusion step was also investigated. As a further technique, the fluidised bed chemical vapour deposition (FBCVD) method allowed the development of Fe₂Al₅ coatings at 550 °C. Furthermore, Si or codiffusion Al‐Si coatings were developed at temperatures as low as 550 °C.     

Compost bedded pack dairy barn management,performance, and producer satisfaction

The objective of the research was to characterize herd performance, producer satisfaction and recommendations, and management practices used by compost bedded pack (CBP) managers in Kentucky (42 farms and 47 CBP facilities). Farms were visited between October 2010 and March 2011. A random selection of cows housed solely in the CBP were scored for locomotion and hygiene. Changes in monthly Dairy Herd Improvement Association performance records, including milk production, SCC, reproductive performance, and daily bulk-tank somatic cell count after moving into the CBP were analyzed using the MIXED procedure of SAS (SAS 9.3; SAS Institute Inc., Cary, NC). The GLM procedure of SAS (SAS 9.3) was used to develop models to describe CBP moisture, CBP temperature at 20.3 cm, and mean herd hygiene. Producers provided 9.0 ± 2.2 m² of pack space per cow (n = 44). Barns constructed with an attached feed alley cost $1,051 ± 407 per cow (n = 40). Barns constructed without an attached feed alley cost $493 ± 196 per cow (n = 13). Kiln-dried shavings required 0.05 ± 0.04 m³ of bedding per cow per day (n = 15). Green shavings required 0.07 ± 0.06 m³ of bedding per cow per day (n = 12). The most-frequently cited benefits of the CBP included cow comfort (n = 28), cow cleanliness (n = 14), and the low-maintenance nature of the system (n = 10). Increased stirring frequency, stirring depth, and ambient temperature increased pack temperature, measured at 20.3 cm below the CBP surface. Increased stirring depth, pasture-adjusted space per cow, and drying rate decreased CBP moisture. Mean herd locomotion and hygiene scores were 1.5 ± 0.3 (n = 34) and 2.2 ± 0.4 (n = 34), respectively. Increased 20.3-cm depth CBP temperature and ambient temperatures improved mean herd hygiene. Bulk-tank somatic cell count decreased from the year before to the year after moving into the CBP barn (323,692 ± 7,301 vs. 252,859 ± 7,112 cells/mL, respectively) for farms using the CBP barn as the primary housing facility (n = 9). Daily milk production, collected from monthly Dairy Herd Improvement Association tests, increased from before moving into the CBP barn to the second year after (29.3 ± 0.3 vs. 30.7 ± 0.3 kg, respectively) for farms using the CBP barn as the primary housing facility (n = 8). Calving interval decreased from the year before to the second year after (14.3 ± 0.1 vs. 13.7 ± 0.1 mo) moving into the CBP barn for farms using the CBP as primary housing (n = 8).     

Improving postponement operation in warehouse: an intelligent pick-and-pack decision-support system

Today, many manufacturers prefer to shift their pick-and-pack postponement operations to third-party logistics companies to lower operational cost and improve mass customisation flexibility. The type of pick-and-pack operation is complicated, as it usually involves a large number of stock keeping units and several warehouse operations. Surprisingly, in most 3PL, the complicated postponement operations are still mainly managed by an experienced warehouse manager, which is an unreliable methodology and often creates many mistakes. A hybrid intelligent system integrating Case-Based Reasoning and Fuzzy Logic is proposed to support the manager in making pick-and-pack postponement decisions. The system comprises a solution-refining module that proposes and holds the details of past pick-and-pack operations. This approach will be of benefit to managers as effective decision support of pick and pack planning can be provided. A case study is used to illustrate the applicability and effectiveness of the approach. Implications of the proposed approach are discussed, and suggestions for further work are outlined.     

纯钛和镍包埋渗铝的热力学研究(英文)

分别在敞开和密闭系统中进行纯钛和纯镍的气相渗铝实验。渗铝实验在1100℃下进行3h,包埋粉末含10%Al、5%NH4Cl和85%Al2O3。在敞开条件下,渗铝后纯钛的表面会生成α(Al)固溶体,样品的质量损失达到32.37%。然而,在密闭条件下,纯钛样品的表面生成TiAl3层和α(Al)固溶体,没有质量损失。热力学分析表明,在敞开条件下对纯钛渗铝时,会生成钛的氯化物,导致其质量减少。而在密闭条件下,由于生成的氯化物会达到平衡状态而使生成反应停止。相反,无论是在敞开或密闭条件下,纯镍样品都可以进行表面渗铝,不会导致质量损失。在两种状态下,镍的表面都生成了AlNi和Ni3Al相。