据国家统计局数据显示，2014 年1-2 月份，家电销售收入达17209.3 亿元，同比下降8%，利润总额达到79.2 亿元，同比增长2.8%。销售利润率4.6%，同比增长0.97 个百分点。

9月，随着进入秋冬季节，空调、冰箱等市场需求量逐渐下滑，进入低位震荡阶段，洗衣机也持续疲软，彩电在家电新技术的促进下，小幅回升。进出口方面，空调出口额保持持续稳定增长。

The Global Procurement of HVAC Systems market is growing at a steady rate across the world. It had a total revenue of US$88.97 billion in 2013 and is expected to reach US$121.04 billion by 2018, growing at a CAGR of 6.35 percent. However, the market is witnessing several factors that affect the demand as well as the price of HVAC systems.

Electric hand dryers are devices used to dry hands and are usually found in public washrooms.

混合磁悬浮装置的各项参数相互影响,决定着整个装置的性能。在满足承重要求的条件下,有必要对该装置的各项参数进行优化研究。为此,提出一种多策略改进粒子群算法,并将其应用到混合磁悬浮承重装置的参数优化中。首先,对混合磁悬浮装置进行介绍,通过分析永磁和电磁悬浮力,以励磁损耗和资金投入最小,和在允许范围内减载程度最高为目标,建立该装置的优化模型。在算法上,通过分析传统粒子群算法的缺陷,首次提出多开端策略来提高种群的多样性,结合反向学习和参数修正等多种策略对粒子群算法进行改进(多策略改进粒子群算法),以广义Schwefel函数为验证函数,通过与其他粒子群算法的比较证明,改进算法具有更强的优势。最后,运用多策略改进粒子群算法对磁悬浮模型进行优化,将优化结果与原有参数进行比较,分析可知该结果更加符合实际情况,通过仿真验证该结果的合理性,为进一步建立实验模型奠定了理论基础。

为了改进自抗扰控制器(active-disturbance rejection control,ADRC)性能,同时解决永磁同步电机(permanent magnet synchronous motor,PMSM)传统直接转矩控制(direct torque control,DTC)中存在的磁链和转矩脉动大以及机械速度传感器的使用降低系统可靠性等问题,提出一种PMSM DTC无传感器运行优化方法。设计了ADRC速度调节器,阐述了将最小二乘支持向量机(LSSVM)最优回归模型有效嵌入ADRC调节器的实现方法,对ADRC进行优化,以提高ADRC观测精度及系统动态响应速度,改善系统的抗干扰能力;同时,在两相静止坐标系下提出基于扩张状态观测器同时对定子磁链和转速进行估计的方法,以降低磁链和转矩脉动,同时实现无传感器运行。仿真和实验结果验证了该方法的可行性和有效性。

The upper operating temperature of tubes in heat exchangers/steam generators is strongly influenced by the degradation that can occur because of the reaction of the exchanger/generator tubing with the deposits that accumulate on the surface of the tubes. In fact, severe corrosion has been observed in some biomass fired systems, particularly with elevated potassium and chlorine concentrations in the deposits. Wood gasifiers have recently been and are currently being constructed at several sites in North America. In these systems, the syngas is burned to produce steam and the performance of the heat exchanger tubes under ash deposits is of great concern. As temperatures of the heat exchangers are increased in an effort to increase their operating efficiency, the performance of the tubes is of greater interest. The corrosion behavior of alloy steel tubes as a function of temperature has been investigated by exposing samples of selected alloys to ash collected from the steam generator fired by syngas produced in wood gasifiers. This study compares corrosion rates from laboratory exposures of synthesis gas and ash at 500 degrees C and 600 degrees C.