温室太阳能加热系统的设计与试验研究

针对温室冬季加热费用高的问题，作者研制了温室太阳能加热系统，介绍了系统的总体设计，详细论述了系统的控制策略和软件设计，实现了系统的自动控制，并对系统进行了应用效果试验。系统经济性分析评价的结果表明，与锅炉和电加热系统相比，使用本系统是经济合理的。     

抽水蓄能电站系统效率的探讨

本文从抽水蓄能电站改善火电主系统能耗特性出发，提出了系统效率的概念，并给出了系统效率的计算模型。计算表明，同机组效率永远小于１的情形相反，系统效率在本文计算范围内均大于１，越是尖峰区，系统效率越高，建议将抽水蓄能电站系统效率同其机组效率并列，同作为这类电站的重特征参数。     

MIXPC涡轮增压系统的研究

从理论、试验及系列化方面对MIXPC系统进行了全面的阐述，MIXPC系统能够避免扫气干扰，降低泵气损失及油耗。MIXPC系统具有尺寸小，质量轻及单涡轮入口结构简单的优点。在巳建立的FVM-TVD模型及程序的基础上进行了试验。试验结果表明：排气阀出口压力波的测试值同模似值十分吻合，流量计算误差也比“有限容积法”的精度高，这说明了FVM-TVD法的有效性，对16V280ZJG柴油机的MIXPC系统进行理论计算及试验研究。其结果表明，相对于MPC系统，脉冲系统，脉冲转换器系统和定压系统，MIXPC系统的性能是令人鼓舞的。在系列化方面，MIXPC系统可用于L4-L10及V8-V20缸的柴油机。     

压缩空气系统优化技术及其应用

本文从系统角度入手，在对某化纤厂压缩空气系统进行全面评估的基础上，结合原有系统的实际情况，综合运用稳定系统压力、增加系统储气能力、增强原有集中控制能力等技术，提高整个压缩空气系统的效率，该案例具有典型的示范作用。     

住区太阳热水供应系统设计流程

从建筑给排水系统设计的角度看，太阳热水供应系统是指以太阳能为热源，可以与其它能源组合，制备生活热水，并通过管路将热水输送到用水点的系统。太阳热水供应系统包括热源系统及热水供应系统两大部分。热源系统即是太阳能行业所规定的将太阳能转换为热能，并在必要时与辅助热源配合使用以加热水的子系统与部件的组合。热水供应系统即热水输送系统，是把热水送到各用水点的管道系统。     

生物质气化发电技术讲座(7)大中型生物质气化发电系统应用实例分析

1 中型生物质气化发电系统。中型生物质气化发电系统一般采用流化床气化工艺，发电规模为400～3000kW。中型生物质气化发电系统在发达国家应用较早，所以技术较成熟，但由于设备造价很高，发电成本居高不下，所以，在发达国家应用极少。近年来，我国开发出了循环流化床气化发电系统，由于该系统有较好的经济性，所以在我国推广很快，已经成为国际上应用最多的中型生物质气化发电系统。     

变风量(VAV)空调系统及其经济分析

本文介绍了变风量系统和定风量系统的特性，并以实际工程为例对两种系统的经济性进行了比较，结果表明虽然变风量空调系统的初投资较大，但它运行时能量消耗少。因此变风量空调系统具有节能、低噪声，室内温度易调节等优点，是值得推广应用的空调系统。     

舒适,节能的冷却吊顶空调系统

冷却吊顶作为一项节能新技术，深沉与置换通风系统相结合使用，使空调系统更加合理完善，在这种空高系统中，冷却吊顶承担了大部分冷却负荷，而通系统只需处理少量新风以满足卫生所需，国外的大量实践表明，同传统空调系统相比，冷却吊顶系统大大改进了室内空气品质，节约了能耗，提高了系统的经济性，本文介绍了冷却吊顶的运行机理，并分析了其优越性。     

基于模型的5 kW SOFC系统操作参数寻优

为延长固体氧化物燃料电池（SOFC）的寿命、提高系统性能，以5 kW平板式SOFC系统为研究对象，在满足功率需求和温度约束的条件下，探究其通过寻优最佳的操作参数组合以实现最高的系统效率。首先采用模块化建模方法，基于工作机理建立SOFC独立发电系统的模型。其次，基于所建立的系统模型，通过定义4个操作参数，并结合系统的热电约束，形成SOFC系统效率优化问题。针对该优化问题，提出一种结合元启发式优化算法的两级优化方案，即将操作参数按照对SOFC系统的影响分为两级，对第一级操作参数进行离散取值，对第二级操作参数采用麻雀搜索算法进行优化。结果表明，所提优化方案可获得全局最优操作点，使SOFC系统满足功率需求和温度约束条件且系统效率达到最优。     

地源热泵系统辅助散热设备及其经济性能

地源热泵系统由于增加了地热换热器而使系统的投资增加，随着系统连续运行时间的增加，系统效率也随之下降。对以冷负荷为主的地区，当冷热负荷的比率超过2时，采用辅助散热设备后，系统的效率提高，同时系统的总投资也减少。当地热换热器出口水温超过当地土壤温度20℃时，可启动辅助散热设备运行。     

电厂管系水击分析

对电厂管系水击激发的管道振动进行了研究,利用有限元方法,对研究的管系进行了有限元建模,把水击基本方程得出的水击力作为加载力,计算出了水击激发的位移、转角响应幅值和激发出的管系模态系数,从计算结果看出水击对管系的动力特性有重要影响,在管道设计时必须加以考虑,最后提出了消除水击影响的措施。     

A new solar and geothermal based integrated ammonia fuel cell system for multigeneration

In this study, a new solar and geothermal based integrated system is developed for multigeneration of electricity, fresh water, hydrogen and cooling. The system also entails a solar integrated ammonia fuel cell subsystem. Furthermore, a reverse osmosis desalination system is used for fresh water production and a proton exchange membrane based hydrogen production system is employed. Moreover, an absorption cooling system is utilized for district cooling via available system waste heat. The system designed is assessed thermodynamically through approaches of energy and exergy analyses. The overall energy efficiency is determined to be 42.3%. Also, the overall exergy efficiency is assessed, and it is found to be 21.3%. The exergy destruction rates in system components are also analysed and the absorption cooling system generator as well as geothermal flash chamber are found to have comparatively higher exergy destruction rates of 2370.2 kW and 643.3 kW, respectively. In addition, the effects of varying system parameters on the system performance are studied through a parametric analyses of the overall system and associated subsystems.     

Analysis and assessment of an advanced hydrogen liquefaction system

In the present work, an advanced hydrogen liquefaction system with catalyst infused heat exchangers is proposed, analyzed and assessed energetically and exergetically. The analysis starts with exergetic considerations on hydrogen liquefaction using different alternatives of pre-cooling including the conversion from normal to parahydrogen. It further explains the fundamentals of a proposed liquefaction process. The goal is then to assess the proposed system, make modifications and improve the system. The present system covers all of these portions of a hydrogen liquefaction system with an ultimate goal of achieving a sustainable and environmentally harmless system. The proposed hydrogen liquefaction system is simulated in the Aspen Plus and the performance of the system is measured through energy and exergy efficiencies. The resulting energy efficiency of the system is calculated to be 15.4%, and the exergy efficiency of the system is found to be 11.5%.     

利用局部关联维数分析机械系统故障信号

对机械系统运行中测量的振动信号进行处理并识别系统的状态。针对非线性系统的特点,用分形维数定量刻画机械系统运行状态。使用分形维数中能直接反映转子系统运行特点的关联维数来获得转子运行故障以及故障发展程度的定量描述。定义并使用了局部关联维数算法,克服了使用单一维数对系统描述的局限性,同时提高了描述转子系统故障的精度,并得到系统状态预测的可靠保证。     

Development of an integrated gasifier-solid oxide fuel cell test system: A detailed system study

A detailed system study on an integrated gasifier-SOFC test system which is being constructed for combined heat and power (CHP) application is presented. The performance of the system is evaluated using thermodynamic calculations. The system includes a fixed bed gasifier and a 5 kW SOFC CHP system. Two kinds of gas cleaning systems, a combined high and low temperature gas cleaning system and a high temperature gas cleaning system, are considered to connect the gasifier and the SOFC system. A complete model of the gasifier-SOFC system with these two gas cleaning systems is built and evaluated in terms of energy and exergy efficiencies. A sensitivity study is carried out to check system responses to different working parameters. The results of this work show that the electrical efficiencies of the gasifier-SOFC CHP systems with different gas cleaning systems are almost the same whereas the gasifier-SOFC CHP systems with the high temperature gas cleaning system offers higher heat efficiency for both energy and exergy.     

风电-抽水蓄能联合运行系统的模拟研究

构建了一个含风电—抽水蓄能联合运行系统的小型模拟电网,并对其拟定了一个风电—抽水蓄能联合运行方案;然后在最大化利用风电的目标下,建立了该方案的经济运行计算分析模型,经对该联合运行系统与普通风电系统的比较计算分析,验证了本模拟方案和计算模型的正确性;同时证明风电—抽水蓄能联合运行系统是最大化开发利用风能资源的有效途径,具有可观的经济效益和社会效益。     

Study of system dynamics model and control of a high-power LED lighting luminaire

The purpose of the present study is to design a current control system which is robust to the system dynamics uncertainty and the disturbance of ambient temperature to assure a stable optical output property of LED. The system dynamics model of the LED lighting system was first derived. A 96 W high-power LED luminaire was designed and built in the present study. The linearly perturbed system dynamics model for the LED luminaire is derived experimentally. The dynamics model of LED lighting system is of a multiple-input–multiple-output (MIMO) system with two inputs (applied voltage and ambient temperature) and two outputs (forward current and heat conducting body temperature). A step response test method was employed to the 96 W LED luminaire to identify the system dynamics model. It is found that the current model is just a constant gain (resistance) and the disturbance model is of first order, both changing with operating conditions (voltage and ambient temperature). A feedback control system using PI algorithm was designed using the results of the system dynamics model. The control system was implemented on a PIC microprocessor. Experimental results show that the control system can stably and accurately control the LED current to a constant value at the variation of ambient temperature up to 40 °C. The control system is shown to have a robust property with respect to the plant uncertainty and the ambient temperature disturbance.     

基于DeviceNet现场总线的快速热处理设备控制系统设计

介绍了一种基于DeviceNet现场总线的快速热处理设备控制系统。首先介绍了该系统的硬件构成,本控制系统采用了基于现场总线和模块化设计思想,使得该系统的能够满足快速热处理设备的加热腔的数量可任意配置,具有很好的可扩展性;然后提出了一个分层的、模块化的、可配置的软件控制系统,并对其进行了简要概述;最后设计了一个基于系统模型的温度控制器,该控制器采用了前馈控制与反馈控制相结合的方法,其中,前馈通道用来预测控制输出,从而提高了系统响应速度;反馈通道用来修正模型误差和外界干扰,从而提高了控制系统的鲁棒性和控制精度。     

基于神经网络的集中供暖系统约束控制

为提高集中供暖系统的热效率,提出了一种基于神经网络的集中式供暖系统的水阀开合度控制策略,引入了障碍李雅普诺夫函数和一个特殊设计的辅助系统来解决控制系统中出现的输入输出约束的问题。采用了一种神经网络逼近器来在线估计系统模型,解决系统传递模型未知的问题。通过模拟仿真同时测试了所提出系统的性能,与传统PID控制系统进行对比,该系统具有良好的适应性和稳定性,有一定的实用价值。     

Thermodynamic analysis of a novel energy storage system with carbon dioxide as working fluid

Recently, energy storage system (ESS) with carbon dioxide (CO₂) as working fluid has been proposed as a new method to deal with the application restrictions of Compressed Air Energy Storage (CAES) technology, such as dependence on geological formations and low energy storage density. A novel ESS named as Compressed CO₂ Energy Storage (CCES) based on transcritical CO₂ Brayton cycle is presented in this paper. The working principle of CCES system is introduced and thermodynamic model is established to assess the system performance. Parametric analysis is carried out to study the effect of some key parameters on system performance. Results show that the increase of turbine efficiency is more favorable for system optimization and the effect of minimum pressures on system performance is more significant compared with maximum pressures. A simple comparison of CCES system, liquid CO₂ system and Advanced Adiabatic Compressed Air Energy Storage (AA-CAES) system is conducted. It is shown that the system efficiency of CCES is lower than that of AA-CAES system but 4.05% higher than that of liquid CO₂ system, while the energy density of CCES system is 2.8 times the value of AA-CAES system, which makes CCES a novel ESS with potential application.