新型节能环保型空调辅助装置系统

随着人们对空调要求的提高,我们提出了一套新型智能换气节能环保空调系统,该系统弥补了传统空调不能换风的设计缺陷,更适合人们的生活需求。通过在室外设计一个换风扇,将室外的新鲜空气通过换风管道引入到室内的出风口,完成对新风的引入,同时,把冷凝水进行回收再利用,利用蒸发散热降低冷凝器温度,提高制冷效率。该设计具有极强的灵活性和经济适用性,既不影响原有空调的运行,也可对传统空调进行改装,使其也拥有新型换气系统,还可达到引入新风、改善室内空气质量的目的。

提升地铁车站作业环境空气质量创新与应用

城市轨道交通一般均地处繁华地带,在建设过程地下空间作业十分普遍,施工过程产生的粉尘造成空气污染,对生产效率造成严重影响,并对作业人员身体健康造成严重危害。青岛地铁灵山卫车站在建设期间设置的自动换风系统,并在区间隧道和车站交接的人防门处设置一套可移动的"窗帘",有效的提升地铁车站作业环境空气质量成功实例,值得推广应用。

The Least Order Observer Based Sensorless Control of PMSG in Direct-Drive Wind Turbines

Permanent magnet synchronous Generator （PMSG） based direct-drive wind energy conversion system （WECS） has been attracting wide attentions. For the special application, sensorless control for PMSG is desired. By widely studying the previous contributes, a novel estimator based on back-EMF is proposed. The estimator is composed of back-EMF observer and a phase-lock-loop （PLL） control to get the rotor-flux speed and position. The estimator not only can be used for interior and surface permanent magnet synchronous generators, but also has a compact and symmetrical structure, which makes it be beneficial for implementation. Compared with previous strategies, the EMF observer is independent of the PLL control, which would simplify the observer design. Meanwhile, the proposed estimator is less sensitive to parameter variations. Based on mathematic models of PMSG, the proposed estimator was analyzed in detail, and the realizing process was also presented. To validate the proposed estimator, the important experiment results are reported.

Power Quality Improvement Using Grid Side Converter of Wind Energy Conversion System

This paper presents the control ofa WECS （wind energy conversion system）, equipped with a DFIG （doubly fed induction generator）, for maximum power generation and power quality improvement simultaneously. The proposed control algorithm is applied to a DFIG whose stator is directly connected to the grid and the rotor is connected to the grid through a back-to-back AC-DC-AC PWM （pulse width modulation） converter. The RSC （rotor side converter） is controlled in such a way to extract a maximum power, for a wide range of wind speed. The GSC （grid side converter） is controlled in order to filter harmonic currents of a nonlinear load coupled at the PCC （point of common coupling） and ensure smooth DC bus voltage. Simulation results show that the wind turbine can operate at its optimum energy for a wide range of wind speed and power quality improvement is achieved.

Control of Doubly Fed Induction Generator under Unbalanced Voltages for Reduction of Torque Pulsation

The unbalanced voltages cause negative effects on the doubly fed induction generator （DFIG） sucn as torque pulsation,and increased stator current. Based on the symmetrical component theory, the torque pulsation is the consequence of the interaction of stator and rotor currents of different sequences. This paper presents a control technique to reduce the effect of unbalanced voltages on the DFIG in wind energy conversion systems. The negative sequence stator voltage is derived from the unbalanced three phase stator voltages. The compensated rotor voltage in terms of the derived negative sequence stator voltage and slip which minimizes the negative stator and rotor currents is proposed. The results from the simulation of control system with steady state model and dynamic model of the DFIG show that additional control loop with compensated voltage can significantly reduce torque and reactive power pulsations.

Energy Performance versus Indoor Environment QualitymNon-traditional Form of Elementary Schools Renovation in Terms of Slovak Republic

The content of contribution is to analyse suggested renovation of school building in term of energy performance and indoor environment quality. There were three selected variants of possible reno ration of school building. At first, it was installation of equipment for heat recovery into existing mechanical ventilation system. There were further evaluated possibilities how to use glass atrium or ground air-heat exchanger in mechanical ventilation system. These suggested variants were analysed in field of energy performance, namely in term of impacts on heat demand for space heating in order to keep required parameters of indoor environment quality according to standard STN EN 15251 （operative temperature, relative air humidity, air change rate）. The analysis was elaborated by using energy simulation tool Design Builder in order to evaluate yearlong operation of buildings.

Simulation of Velocity and Temperature Distributions of Displacement Ventilation System with Single or Double Heat Sources

In order to obtain a better understanding of flow characteristics of displacement ventilation, the three-dimensional numerical models are developed using the CFD technology. The numerical simulation results are verified by experiments, based on this, the velocity and temperature distribution of three-dimensional displacement ventilation system with single and double heat sources are studied. Velocity and temperature fields under two different cases of heat source are analyzed and compared. The numerical results show that there are three layers in vertical temperature fields of displacement ventilation system with single or double heat sources, and the vertical temperature distribution of single heat source is different from that of double heat sources. When indoor load is large, the comfort requirement of people indoor can＇t be satisfied with displacement ventilation system only, thus an additional refrigeration system is necessary. Furthermore, under the condition of two heat sources, the displacement ventilation parameters can＇t be computed simply according to single heat source inlet parameters, therefore the interaction between heat sources should be considered.