Heat and electricity consumption of large industrial energy users in The Netherlands

On the basis of information that can be extracted from existing databases, combined with information from literature and interviews, a database called BIN has been constructed containing data about the consumption of fuel, steam and electricity by approximately the 300 largest energy-consuming industrial plants in The Netherlands. Comparison with national statistics shows that the industrial plants incorporated in the database are responsible for 80% of the total industrial demand on primary energy carriers (excluding their use as feedstock). Thirteen industrial plants already cover 50% of this demand. The paper and board industry, the refineries, the chemical industry, and the basic metal industry are almost consumption over size classes has been derived. This article also gives the temperature distribution of the industrial steam consumption in The Netherlands. Of the 64 million tonnes of steam produced in boilers in the industrial plants included in the database the weighted average enthalpy is 3.17 MJ/kg and the average exergy is 1.29 MJ/kg, both with liquid water of 10°C as the reference. The plant-specific data included in the database can be used for research into industrial energy conservation measures, e.g. the combined generation of heat and power (CHP).     

Gas turbine exhaust gas heat recovery at South Baghdad (Iraq) power plant

Gas turbine exhaust is usually relatively clean, especially the exhaust from natural gas turbines. The use of such gases to improve the overall thermal efficiency of a steam power plant has the advantage of reducing the cost of cleaning the equipment and reducing the maintenance costs of the heat recovery equipment used in the application.In this paper, two proposals for recovering the waste energy of the exhaust gases from a gas turbine unit, fuelled by natural gas at south Baghdad Power Plant (Iraq) are discussed. The proposals cover improvements to the thermal efficiency of a steam power plant installed near the gas turbine unit. The first proposal is to use the exhaust gases to preheat the feed water at four feed water heaters, in order to increase the power output. This arises because of the savings in the amount of steam extracted at a different level used for preheating the feed water line. The second proposal is to use the thermal energy in the exhaust gases to reheat the extracted stream, at five points at a high thermal potential, to increase the thermal gain at the preheating feed water line. This avoids the complexity associated with rejection of the extracted steam. The first roposal shows that a 1.22–14.9% saving in fuel consumption is achievable and the overall thermal efficiency of the steam power plant becomes 29–34% (at different gas turbine plant loads). The second proposal shows that a 2.3–7.35% saving in fuel consumption can be attained and the corresponding thermal efficiency will be 30.3–32%.     

国产优化300／600MW汽轮机通流部分气动设计──第一部分：设计体系与通流设计特点

本文介绍了用于大功率汽轮机通流部分气动设计的准三维／全三维设计体系。使用该设计体系把复合倾斜叶片、可控涡流型等先进的汽轮机气动设计思想，成功地应用到了３００／６００ＭＷ汽轮机的改型设计中，以期较大程度地改进机组的热力性能。     

650℃超超临界1000 MW机组回热系统的参数优化

发展更高参数超超临界汽轮机组是提高发电热效率和降低燃煤消耗量的主要方向。随着高温合金材料技术的发展,目前已具备发展主蒸汽650℃超超临界机组的条件,主蒸汽和再热蒸汽温度的提高,对回热系统的设计也提出了新的要求。本文设计了超超临界1000 MW汽轮机组的回热系统,分析了主蒸汽和再热蒸汽压力对机组热力性能的影响规律,采用遗传算法优化了各级抽汽参数,汽轮机发电热耗率低于6940 kJ·(kW·h)^-1。     

The exergy carry-over index for a utility system

An exergy analysis has been conducted for the utility system of an integrated sugar cane processing plant. A 22 MW boiler supplies steam to five turbines. The availability or exergy analysis establishes the amount of chemical and thermal energy that can possibly be transformed into work. Of the 100 units of available energy from the fuel, only 62.2 units are exergy. The steam cycle absorbs 60.3 energy units, of which 21.0 are exergy. The exergy carry-over index for the boiler is 0.56. The steam transfers to the turbines 2.2 energy units, all of which are exergy. The index is 2.86 for the steam cycle and 1.61 for the combined installation.     

Criteria for integration of combined cycle cogeneration systems in the process industries

Cogeneration systems often provide a very effective means of integrating power generation with the provision of thermal energy to an industrial process. Various types of power generating machines can be used, but combined cycle cogeneration systems can offer significant advantages over other technologies in many medium and large scale applications. The systems that are used consist of fired prime movers (usually gas turbines), discharging their exhaust heat into heat recovery steam generators. The steam raised in this way is passed through back-pressure steam turbines to extract additional power before finally delivering its residual heat content to process heating duties.This paper presents an overview of the economic trade-offs in the design of single cycle and combined cycle systems. Generalizations are derived from this investigation, leading to the identification of three distinct classes of problem for which different types of cogeneration systems (combined cycle or single cycle) are appropriate. Case study results are presented to illustrate the principles employed.     

Influences on indoor radon concentrations in Riyadh,Saudi Arabia

The influences on indoor radon concentrations in Riyadh, Saudi Arabia survey was carried out for 786 dwellings. The measurements were obtained by using a passive integrating ionization system with an E-Perm^® Electret ion chamber. Radon levels ranged from 1 to 195 Bq m⁻³, with a mean value of 24.68 Bq m⁻³, the geometric mean and the geometric standard deviation are 21 and 2 respectively. 98.5% of the results were below the action level recommended by WHO of 100 Bq.m⁻³. The results were found to vary substantially due to types of houses and rooms, ventilation, seasons and building materials. Radon concentrations were higher in houses with no ventilation systems, and central air conditioners, and were relatively lower in well ventilated houses with red bricks and water air conditioners.     

The advanced steam and gas technology

One of the directions of creating advanced gas and steam power units is usage of new working substances (freons) in the steam turbine stage. This paper presents the authors’ method for estimation (which is the scientific novelty) and results of calculating the efficiency and design-layout parameters of assemblies of a steamand gas power unit (SGU)with the freon technology. It is shown that the use of freons with supercritical parameters in SGU makes it possible to obtain efficiency on a level of 58% and apply more compact (compared to conventional) turbines and once-through recovery boilers, and a regenerator and condenser whose design-layout parameters are comparable with similar conventional designs.     

冷凝器台数的优化配置与节能

选取厦门商业冷冻公司2004年压缩机的运行记录,分析统计出运行工况下每个时间段冷凝器实际排热量与系统冷凝器额定总排热量的比值,将其定义为部分负荷率,得出各部分负荷的运行时间及运行规律。并据此规律进行冷凝器优化配置分析,计算优化配置方案的能耗和回收期。结果表明:冷凝器按部分负荷的变化规律配置,有较大的节能潜力。根据制冷装置在厦门的特定条件计算分析,当冻结能力为20吨/天时,冷凝器优化配置的节能可达49.1%,回收期在两年之内;当冻结能力为10吨/天时,优化配置后节能可达55%,不增加初投资。     

Treatment of petroleum refinery wastewater by ultrasound-dispersed nanoscale zero-valent iron particles

Petroleum refineries release wastewater, which is rich in organic pollutants and cannot be treated easily. This study presents the treatment of petroleum refinery wastewater using nanoscale zero valent iron (NZVI) in the presence of ultrasonication. NZVI characteristics were analyzed using SEM and XRD. The influence of NZVI dosage and initial pH on % chemical oxygen demand (COD) reduction was studied. From the results, it can be inferred that a dosage of 0.15 g/l and an initial pH are optimum for the effective degradation of effluents. The degradation data were found to follow first order kinetics. The results indicate that using NZVI in combination with ultrasonication is an efficient method for the treatment of petroleum refinery wastewater.     

国产优化300／600MW汽轮机通流部分气动设计 第二部分：叶栅优化与完善化设计

本文介绍叶栅优化与完善化设计方法。针对３００／６００ＭＷ汽轮机高、中、低缸叶栅不同的气动和几何特点，运用Ｓ１流面正、反问题和杂交问题程序，对叶栅进行优化或完善化设计。试验研究和工程实践表明这套设计方法是成功的。     

Low-frequency noise from large wind turbines

As wind turbines get larger, worries have emerged that the turbine noise would move down in frequency and that the low-frequency noise would cause annoyance for the neighbors. The noise emission from 48 wind turbines with nominal electric power up to 3.6 MW is analyzed and discussed. The relative amount of low-frequency noise is higher for large turbines (2.3-3.6 MW) than for small turbines (≤ 2 MW), and the difference is statistically significant. The difference can also be expressed as a downward shift of the spectrum of approximately one-third of an octave. A further shift of similar size is suggested for future turbines in the 10-MW range. Due to the air absorption, the higher low-frequency content becomes even more pronounced, when sound pressure levels in relevant neighbor distances are considered. Even when A-weighted levels are considered, a substantial part of the noise is at low frequencies, and for several of the investigated large turbines, the one-third-octave band with the highest level is at or below 250 Hz. It is thus beyond any doubt that the low-frequency part of the spectrum plays an important role in the noise at the neighbors.     

快速应对电网闪对EAST低温系统影响研究

EAST氦低温系统是EAST(Experimental Advanced Super-conducting Tokamak)先进超导托卡马克实验装置重要子系统之一;EAST氦低温系统是高能耗能系统,拥有7台氦压缩机(4台低压缩机,3台高压缩机),总功率达到1.4 MW左右,由于EAST实验是连续运行(每次在120天以上),中间不能有停机、停电等事故,否则实验无法正常运行。其供电稳定性是个大问题,对供电系统、变电站的要求都很高;然而在实验期间由于一些非人为因素,还是出现几次"电网闪"跳电事故,低温系统压缩机部分或全部停机、氦透平膨胀机全停、冷却水泵系统全停、真空泵系统全停等事故。若事故处理不当会导致丢气、管道压力过高、液氦容器爆炸、损坏磁体等严重后果。文中给出了EAST实验期间出现电网闪的事故时进行相应处理步骤与一些快速应对的操作经验。     

燃气轮机合成气燃烧室燃料气加湿实验研究

本文针对一种燃用合成气的40MW级燃气轮机燃烧室,进行了该型燃烧室的全压燃料气蒸汽加湿试验研究,得到了燃烧室在基本负荷下随加湿量变化污染物排放、燃烧室内动态压力、火焰筒壁面温度等重要参数的变化规律,分析了燃料气加湿对燃气轮机总体性能、污染物排放、火焰筒壁温及燃烧稳定性方面的影响,探讨了燃料气加湿对合成气燃烧中Nox生成的机理性作用. 研究表明燃料气加湿是降低燃用合成气的燃气轮机氮氧化物排放的有效方式.     

Analysis of an integrated vapour compression and a waste heat dehumidifier A/C system

A compact, self-contained energy efficient air-conditioning system is presented. It has a vapour compression (VC) unit combined with a rotary solid desiccant dehumidifier. The drying matrix is regenerated entirely using the waste heat of the VC unit by a heat pump in a heat recovery system.The governing equations are given and are numerically solved for a typical case study. Computations show that employing parallel flow rather than counterflow configurations through the matrix can reduce the regeneration heat required by about 40%. Equations are solved for a practical range of cycle duration from 180 to 900 s. Results show the variations of temperature and water content for the matrix as well as the flowing air streams.The overall cooling COP achieved by the combined system reached 1.73 for design conditions in Jeddah, Saudi Arabia, which is 25% more than that of the VC alone. Whenever the ARI conditions are applied, the combined system showed an overall COP of 1.76 with 27% energy savings compared to the VC alone.     

Seasonal and location dependence of indoor and soil radon concentrations in two villages,Najran region,Saudi Arabia

Seasonal (winter-summer) indoor and soil radon comparison is made in two villages in Najran region, south west of Saudi Arabia, using CR-39 Dosimeter. Summer indoor radon concentrations were measured in the villages of Fara Al-Jabal and Hadadah. The respective winter-summer average values of 42 ± 4 Bq m⁻³ and 74 ± 5 Bq m⁻³ are measured in Fara Al-Jable village and the average values of 47 ± 4 Bq m⁻³ and 76 ± 5 Bq m⁻³ are measured in Hadadah village. The respective winter-summer soil values are 1.40 ± 0.21 kBq m⁻³ and 0.99 ± 0.04 kBq m⁻³ in Fara Al-Jabal village while those measured in Hadadah village are 2.90 ± 0.17 kBq m⁻³ and 1.40 ± 0.66 kBq m⁻³. Indoor radon levels are found to be seasonal dependent while that of soil are found seasonal and location dependent. Meteorological and geological factors are expected to have caused the measured significant differences in radon levels in dwellings and soil in the two villages.     

燃气轮机机理建模与性能监测

燃气轮机电厂是电网调峰和分布式能源系统中的重要组成部分,其安全稳定运行和快速响应对燃气轮机性能要求较高,因此对燃气轮机进行性能监测有着重要意义。本文采用了模块化机理建模的方法,基于MATLAB平台,建立了简单循环单轴燃气轮机数学模型,并以某典型9E燃气轮机的实际运行数据进行了模型验证,结果表明本文所建模型可以较准确地反映燃气轮机性能。此外,本文所建数学模型具有一定的普适性,通过输入不同的设计参数,可以用于不同等级、不同型号燃气轮机的性能研究。     

燃气轮机合成气燃烧室中燃烧噪声的现场测试与分析

燃气轮机的燃烧噪声是反映燃烧室燃烧稳定性的主要参数.本文对国内某座煤基IGCC示范电站的40 MW级燃气轮机在诸多运行条件下的燃烧噪声进行了现场测试,分析了气液双燃料喷嘴在燃烧轻柴油、燃烧合成气以及油气切换过程中燃烧室的燃烧噪声,另外分析了合成气掺烧驰放气与合成气加湿对燃烧稳定性的影响.结果表明:合成气燃烧室在油气切换过程中燃烧噪声会增加,但距离振荡燃烧的阈值仍有很大的裕度;烧合成气时随着燃气轮机功率增加燃烧噪声降低;合成气加湿时随着蒸汽流量增加污染物NOx排放显著降低,并且燃烧噪声也有降低的趋势.     

Developments in geothermal energy in Mexico—part thirty-four. Numerical steady-state simulation of the steam supply system of the cerro prieto geothermal plant

The philosophy used in the mathematical modelling of the steam supply network of Cerro Prieto geothermal power stations is described. In order to form the simulation model of this system, mathematical models were developed for: the surface equipment such as separators, pressure control stations, steam turbines, low and high pressure interconnections, purges and wells. With the above mentioned models a computer programme was produced which operating conditions in the steam supply system.     

Correlation between radon exhalation and radium content in granite samples used as construction material in Saudi Arabia

Measurements of radon exhalation for a total of 205 selected samples of construction materials used in Saudi Arabia were carried out using an active radon gas analyzer with an emanation container. It was found that granite samples were the main source of radon exhalation. The radon exhalation rates per unit area from these granite samples varied from below the minimum detection limit up to with an average of 1.5 . The radium contents of 27 granite samples were measured using an HPGe-based γ spectroscopy setup. The ²²⁶Ra content of the granites varied from below the minimum detection limit up to , with an average of . The linear correlation coefficient between exhaled radon and radium content was found to be 0.90.