曝气设备的技术指标与节能

深入分析了曝气设备各指标间的矢系,区分了设备的效能指标与规格指标,探讨了曝气设备选择上的困惑,估算了曝气设备选择不当可能造成的经济损失,提出了如下观点：动力效率是曝气设备惟一的效能指标,应大力推广动力效率高的设备,坚决淘汰动力效率低的设备;充氧能力和氧转移效率是规格指标;在评价曝气设备性能、选择曝气设备类型时,氧转移效率不应考虑。     

浅谈矿山压风设备的经济运行

压风设备是煤矿耗电量较大的设备之一,提高压风设备运行效率,对节约电能和降低生产成本有着非常重要的意义,论述了提高压风机运行效率的措施及方法,提出了合理化建议。     

对动力设备效率的几点看法

一个合理的效率定义模式，应该从绝对量（损）和相对量（效率）两个角度准确地体现设备的热力学完善度—设备实际状况接近理想可逆状况的程度。从这一点出发，通过对蒸汽透平、燃气轮机等动力设备现行目的效率表达式的探讨，对该类设备的效率定义模式提出了不同的看法，给出了一种能够准确反映其热力学完善度的效率表达式     

提高煤矿巷道掘进效率的措施研究

煤矿井下开采过程中巷道掘进效率对开采效率起着显著的制约作用。为此,需要采取措施提高巷道掘进效率。分析了巷道掘进效率的影响因素,主要包括地质条件、掘进设备、支护技术和施工管理水平,探讨了提高巷道掘进效率的措施,主要包括加强地质勘探、采用先进的掘进设备、提升管理水平和提升智能化水平,可以为煤矿巷道的高效掘进提供一定的参考。     

光伏行业扩散炉的技术现状及发展趋势

从降低生产成本和提高电池转换效率方面出发,介绍了太阳电池扩散设备的最新进展,并对各种新型设备作出了评价和展望。     

对动力设备Yong效率的几点看法

一个合理的Ｙｏｎｇ效率定义模式，应该从绝对量和相对量两个角度准确地体现设备的热力学完善度－设备实际状况接近理想可逆状况的程度。从这一点出发，通过对蒸汽透平，燃气轮机等动力设备现行目的的Ｙｏｎｇ效率表达式的探讨，对该类设备的Ｙｏｎｇ效率定义模式提出了不同的看法，给出了一种能够准确反映其热力学完善度的Ｙｏｎｇ效率表达式。     

电厂理论效率及其设备效率

普通电厂和联合电厂采用理论效率（输出功被最大可能可逆输出功所除）已被公认。但适用于电厂设备的第二定律效率却有若干种提法，而且它们没有普遍一致的用法。鉴此推存了适合设备效率的几个特殊定义。这些定义与公认的电厂理论效率取得一致，并将此方法用于电厂理论效率的计算     

轧制油回收设备中布风系统优化模拟研究

采用Fluent软件模拟了轧制油回收设备的气流分布。研究了两种不同布风系统对气流分布的影响。结果表明降低进气孔孔径,增加进气孔数目能够有效提高整个回收设备的回收效率。布风系统得到优化后,回收设备中气流分布更为均匀平稳。硅藻土与热空气的接触机率增大,提高了含油硅藻土中轧制油的回收效率。含油硅藻土能获得最佳的热量,避免了高能条件下油品质量恶化。     

多管除尘脱硫一体化设备的节能改造及分析

沈阳市某供热公司于2017夏季"三修"期间对三号锅炉的炉排进行了改造,将原有链条炉排改为链条-往复炉排型复合炉排,现有炉排烧的煤种由原来的标煤改为了劣质煤,劣质煤的灰分及硫份高,这导致了烟尘颗粒物及二氧化硫再度超标。对3~#锅炉的多管除尘脱硫一体化设备的烟管套设疏波器以进一步提升设备的除尘脱硫效率,选用Gambit软件建立模型,并应用Fluent软件进行气液两相流的仿真模拟,模拟结果显示:设备烟管增设疏波器后,设备的除尘脱硫效率提升效果明显。因此,以模拟结果为依据,在工程实际中对设备的烟管套设疏波器,并投入运行,对比实测结果显示:设备除尘效率提升了6.5%,脱硫效率提升了8.6%,烟尘及SO_2的排放标准大大满足了国家排放标准。     

对蒸汽透平等动力设备Yong功率的探讨

Ｙｏｎｇ效率应准确体现设备或装置热力学完善度－设备或装置实际状况接近理想可送状况的程度。从这一点出发，本文通过对蒸气透平、燃气轮机等动力设备Ｙｏｎｇ效率表达式的探讨，提出了不同的见解和看法，给出一种新的目的Ｙｏｎｇ效率表达式，以能够准确体现设备对Ｙｏｎｇ的有效利用程度。     

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.     

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。     

模块化分布式热电联供技术与实践

本文介绍了分布式热电联供系统,分析了分布式热电联供系统当前的发展形势。同时,也指出了国内冷热电联供推广过程中的一些制约因素。在此基础之上,提出了模块化分布式热电联供系统的概念,并且从几个方面阐述了模块化分布式热电联供系统的优势。最后,以实例说明了模块化的分布式热电联供系统的合理性。模块化冷热电联供必将成为热电联供系统设计和运行管理的有效模式。     

Thermodynamic modeling and exergy analysis of proton exchange membrane fuel cell power system

The proton exchange membrane (PEM) fuel cell (PEMFC) is equipped with a series of auxiliary components which consume considerable amount of energy. It is necessary to investigate the design and operation of the PEMFC power system for better system performance. In this study, a typical PEMFC power system is developed, and a thermodynamic model of the system is established. Simulation is carried out, and the power distribution of each auxiliary component in the system, the net power and power efficiency of the system are obtained. This power system uses cooling water for preheating inlet gases, and its energy-saving effect is also verified by the simulation. On this basis, the exergy analysis is applied on the system, and the indexes of the system exergy loss, exergy efficiency and ecological function are proposed to evaluate the system performance. The results show that fuel cell stack and heat exchanger are the two components that cause the most exergy loss. Furthermore, the system performance under various stack inlet temperatures and current densities is also analyzed. It is found that the net power, energy efficiency and exergy efficiency of the system reach the maximum when the stack inlet temperature is about 348.15 K. The ecological function is maintained at a high level when the stack inlet temperature is around 338.15 K. Lower current density increases the system ecological function and the power and exergy efficiencies, and also helps decrease the system exergy loss, but it decreases the system net power.     

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%.     

太阳能与空气源热泵复合式供暖系统在西安地区的应用特性分析及评价

以西安地区的某个房间为研究对象,采用TRNSYS软件针对该房间分别应用太阳能集热系统、空气源热泵系统及太阳能与空气源热泵复合式供暖系统进行供暖时的情况进行了分析.首先,建立了太阳能与空气源热泵复合式供暖系统的仿真模型,并对其正确性进行了实验验证;其次,对比分析了在3种运行模式下各个系统的运行特性;最后,以系统能耗及能效...     

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.     

水工质波浪能装置液压系统及其监测系统的设计

针对波浪能发电装置的液压系统存在环境污染、安全性差和工作可靠性差等问题,设计一种以水为工质的波浪能发电装置液压系统,对系统组成和液压元件设计进行分析,有效解决传统油压传动存在的问题,为海洋环境中液压系统的优化设计提供一种新思路.同时设计一种基于STM32单片机的液压参数监测系统,可实现对压力、温度、流量、转速的实时监测...     

Dynamic modeling of a proton exchange membrane fuel cell system with a shell-and-tube gas-to-gas membrane humidifier

The proton exchange membrane fuel cell (PEMFC) system with a shell-and-tube gas-to-gas membrane humidifier is considered to be a promising PEMFC system because of its energy-efficient operation. However, because the relative humidity of the dry air flowing into the stack depends on the stack exhaust air, this system can be unstable during transients. To investigate the dynamic behavior of the PEMFC system, a system model composed of a lumped dynamic model of an air blower, a two-dimensional dynamic model of a shell-and-tube gas-to-gas membrane humidifier, and a one-dimensional dynamic model of a PEMFC system is developed. Because the water management during transient of the PEMFC system is one of the key challenges, the system model is simulated at the step change of current. The variations in the PEMFC system characteristics are captured. To confirm the superiority of the system model, it is compared with the PEMFC component model during transients.     

Modeling and control of a wind fuel cell hybrid energy system

This paper describes a hybrid energy system consisting of a 5 kW wind turbine and a fuel cell system. Such a system is expected to be a more efficient, zero emission alternative to wind diesel system. Dynamic modeling of various components of this isolated system is presented. Selection of control strategies and design of controllers for the system is described. Simnon is used for the simulation of this highly nonlinear system. Transient responses of the system for a step change in the electrical load and wind speed are presented. System simulation results for a pre-recorded wind speed data indicates the transients expected in such a system. Design, modeling, control and limitations of a wind fuel cell hybrid energy system are discussed.