Impact of summer office set air-conditioning temperature on energy consumption and thermal comfort

To explore the relationship between summer office set air-conditioning temperature and energy consumption related to air conditioning use to provide human thermal comfort,a comparison experiment was conducted in three similar offices at temperatures of 24,26 and 28 ℃ respectively. A thermal comfort questionnaire survey was conducted. It is demonstrated that air-conditioner energy consumption at the set temperature of 28 ℃ is 113% and 271% lower than at 26 ℃ and 24 ℃,respectively. A linear relationship exists between air-conditioner energy consumption and the indoor and outdoor temperature difference. When comfortably dressed,over 80% of research participants accept the set temperature of 28 ℃. The regression analysis leads to a neutral temperature of 26.2 ℃ and an acceptable temperature of 28.2 ℃ for over 80% of the research participants subjects,indicating that the current 26 ℃ set temperature for offices in summer,required by Chinese General Office of the State Council,can be increased to 28 ℃. Moreover,analysis of predicted mean vote(PMV) index shows that a set temperature of 27 ℃,not 26 ℃,is sufficiently comfortable for office staff wearing long-sleeve shirts,long pants and leather shoes.

Energy consumption in rock fragmentation at intermediate strain rate

In order to determine the relationship among energy consumption of rock and its fragmentation, dynamic strength and strain rate, granite, sandstone and limestone specimens were chosen and tested on large-diameter split Hopkinson pressure bar (SHPB) equipment with half-sine waveform loading at the strain rates ranging from 40 to 150 s- 1. With recorded signals, the energy consumption, strain rate and dynamic strength were analyzed. And the fragmentation behaviors of specimens were investigated. The experimental results show that the energy consumption density of rock increases linearly with the total incident energy. The energy consumption density is of an exponent relationship with the average size of rock fragments. The higher the energy consumption density, the more serious the fragmentation, and the better the gradation of fragments. The energy consumption density takes a good logarithm relationship with the dynamic strength of rock. The dynamic strength of rock increases with the increase of strain rate, indicating higher strain rate sensitivity.

Analysis of Energy Consumption and Energy Conservation Measures for RFCCU at Shengli Petrochemical Company

This article introduces a string of energy conservation measures adopted over the past sev- eral years by the RFCC unit at Shengli Petrochemical Complex, including the optimization of feedstock properties, the adoption of high-efficiency atomizing nozzles, the revamp of CO boiler, the atomization by means of dry gas, the post-burning of flue gas as well as the application of frequency converting machines and pumps, resulting in ideal effects. The energy consumption of the RFCC unit was gradually decreased to 2984.25 MJ/t from the original level of 3716.99 MJ/t. After comparing basic energy con- sumption values with actual consumption values, the authors have set forward measures for further energy conservation, such as the recovery of low-temperature excess heat contained in oil/gas streams exiting from the fractionation tower top, addition of the fourth cyclone, delivery of hot oil slurry, and heat tracing with hot water.

Impact of Demographic Transition on Household Energy Consumption: A Case from China

Understanding how aging population and low fertility affect household energy consumption is important for optimizing household energy consumption and reaching effective policies.This paper studies the impacts of demographic transition on household energy consumption based on panel data of 30 provinces in China from 2005 to 2016.Child-age dependency rate(CDR)and old-age dependency rate(ODR)are selected to track the shifts in age structure.They are introduced into a STIRPAT model to measure their impacts on household energy consumption.Besides,8 representative regions are additionally chosen and investigated to find some regional characteristics.The results show that current demographic transition to aging population expands household energy consumption.The aging population and low fertility cause additional challenges for energy saving and emission reduction.Household energy consumption in less developed areas is more likely to be affected by CDR and ODR.Regions with large population are also more easily influenced by demographic transitions especially CDR.This study emphases the effects of demographic elements on household energy consumption.It indicates that continuous optimization of household energy consumption structures should be based on population dynamics.

Elasticity Ratio of Resource Consumption and the Resource Consumption

Today the resources are becoming scarcer, which should not be regarded as unexhausted any more. Correspondingly, the production would be constrained by the scarcity of resources clearly. Then the economic researchers would pay much more attention to reducing the consumption of natural resources in the future. Therefore this paper brings foreword the conception of elasticity ratio of resource consumption based on the concept of elasticity and analyzes the relationship between the parameters. For the certain relationships between the elasticity ratio of resource consumption and resource consumption, this paper will try to reveal, to keep economy growing while resource consumption reducing, what conditions should be met as to the relationships among resource productivity, its growth rate, energy saving efficiency, economic growth rate and elasticity ratio of resource consumption. This paper proves the relationship between the China＇s energy consumption and economy growth using statistic data from 1978 to 2003.

Estimate of China's energy carbon emissions peak and analysis on electric power carbon emissions

China＇s energy carbon emissions are projected to peak in 2030 with approximately 110% of its 2020 level under the following conditions： 1） China＇s gross primary energy consumption is 5 Gtce in 2020 and 6 Gtce in 2030; 2） coal＇s share of the energy consumption is 61% in 2020 and 55% in 2030; 3） non-fossil energy＇s share increases from 15% in 2020 to 20% in 2030; 4） through 2030, China＇s GDP grows at an average annual rate of 6%; 5） the annual energy consumption elasticity coefficient is 0.30 in average; and 6） the annual growth rate of energy consumption steadily reduces to within 1%. China＇s electricity generating capacity would be 1,990 GW, with 8,600 TW h of power generation output in 2020. Of that output 66% would be from coal, 5% from gas, and 29% from non-fossil energy. By 2030, electricity generating capacity would reach 3,170 GW with 11,900 TW h of power generation output. Of that output, 56% would be from coal, 6% from gas, and 37% from non-fossil energy. From 2020 to 2030, CO2 emissions from electric power would relatively fall by 0.2 Gt due to lower coal consumption, and rela- tively fall by nearly 0.3 Gt with the installation of more coal-fired cogeneration units. During 2020--2030, the portion of carbon emissions from electric power in China＇s energy consumption is projected to increase by 3.4 percentage points. Although the carbon emissions from electric power would keep increasing to 118% of the 2020 level in 2030, the electric power industry would continue to play a decisive role in achieving the goal of increase in non-fossil energy use. This study proposes countermeasures and recommendations to control carbon emissions peak, including energy system optimization, green-coal-fired electricity generation, and demand side management.

基于DeST和EnergyPlus的某被动式办公建筑能耗浅析

本文论述使用DeST软件和EnergyPlus软件对比验证河南省某园区一栋办公建筑全年逐时负荷和能耗。通过相同的工况设置及空调能效,计算建筑综合节能率,应用能耗模拟软件来分析被动式建筑相对于一般建筑的节能优势。

Analysis on the Output Elasticity and Contribution Rate of Energy Consumption to Economic Growth in China's Yangtze River Economic Zone

Many studies have shown that energy consumption plays an important role in economic growth.The paper researches the influence of energy consumption on economic growth in China’s Yangtze River Economic Zone.The paper divides the energy of Yangtze River Economic Zone into the coal,the oil,the natural gas and the electricity and explores the influences of coal consumption,gas consumption,natural gas consumption and electricity consumption on economic growth quantitatively using an extended production function model.The paper mainly uses two methods.The first method is the output elasticity analysis.The paper calculates the four energy consumption’s output elasticity to economic growth to compares the influences of energy consumption in terms of out output elasticity.The second method is the contribution rate analysis.The paper calculates the contribution rates of four energy consumption to economic growth to compare the influences of four energy consumption on economic growth in terms of contribution rate.The paper makes an empirical analysis on the influence of energy consumption on economic growth in China’s Yangtze River Economic Zone.Analysis results show that oil consumption has the greatest influence on economic growth in China’s Yangtze River Economic Zone,in terms of both output elasticity and contribution rate,followed by natural gas consumption,electricity consumption and coal consumption.

A Joint Mobility Management Approach and Data Rate Adaptation Algorithm for IEEE 802.15.4/ZigBee Nodes

This paper presents an original approach to reduce energy consumption in an IEEE 802.15.4/ZigBee cluster tree network related to a backbone network. Our approach uses an enhanced mobility management of end devices combined with a rate adaptation algorithm. The mobility management approach anticipates link disruption and relies on a speculative algorithm that does not require scanning neighbor cells. The joint mobility management and rate adaptation methods are based on the link quality indicator (LQI). It is demonstrated that even in a noisy environment, the energy consumption as well as the latency of mobile devices can be significantly reduced.

Characteristics of Heart Rate Changes of Elite Sprinters during Speed Training

Objective:To infer the training load from the characteristics of heart rate changes of elite sprinters during maximum intensity training.Methods:Different training loads were determined according to different running distances.Multi-person running in the same group was used to collect the heart rate data of elite sprinters during speed training.Results:the heart rate level was directly related to the exercise load.During the maximum intensity exercise,the heart rate generally increased for about 12 s after the race,which was about 110%of the end-point heart rate.Compared with the low load group(60m),the heart rate of the high load group(100m)continued to rise,but the maximum heart rate level was higher than that of the low load group.The exercise intensity and heart rate change rate of the low load group are greater,the work done by the high load group is more,and the envelope area of the heart rate curve is larger.During intermittent training,under the condition of controlling the interval between groups,the heart rate curve envelope area of the low load group is small,the physical recovery is good,the parameter consistency of each group is good,the heart rate curve envelope area of the high load group is large,and the heart rate response decreases gradually.

数模联动的多特征工件加工能耗预测方法研究

在实际切削加工过程中材料去除率是不断变化的,现有将其视为恒量的能耗建模方法难以实现能耗准确预测。为了提高切削过程能耗预测精度,提出了一种基于材料去除率的数模联动加工能耗预测方法。首先,基于切削过程刀具与工件的接触关系分析了切入、完全切入和切出阶段材料去除率变化规律,并对相应的加工能耗特性进行了分析;其次,提出了数据驱动的刀具切入,切出阶段加工能耗预测方法,以及模型驱动的完全切入阶段加工能耗预测方法,实现加工过程能耗准确预测;最后,利用实验案例验证了所提模型及方法的有效性,为今后研究能耗预测精度奠定了基础。

基于能量原理不同含水率下煤岩体变形破坏能量损伤演化机制

为探究不同含水率下煤岩体在变形破坏过程中的能量演化规律与损伤演化特征,对双马一矿煤岩体开展了在不同含水率条件下单轴压缩试验,基于能量计算及最小耗能原理,分析不同含水率下煤岩体能量耗散特征及损伤演化机制,结果表明:不同含水率下煤岩体力学性质不同,峰值应变与含水率呈正相关,抗压强度、弹性模量与含水率呈负相关;煤岩体含水率越高,其在峰值处弹性应变能及破坏吸收总应变能越小,耗散能占总应变能比例越高;基于最小耗能原理建立的损伤本构模型表明:随着煤岩体含水率增加,损伤门槛值逐渐降低;干燥状态下,煤岩体在应力峰值处损伤变量分别为0.36、0.28,当含水率增至自然状态时,煤岩体在应力峰值处损伤变量值分别下降0.09、0.18,但当含水率增至饱水状态时,煤岩体在应力峰值处损伤变量值反而分别大幅度上升0.102、0.49,总体呈先减后增的发展趋势;进一步建立了不同含水率煤岩损伤应变能释放率演化模型,低含水率煤岩较干燥煤岩的最大损伤应变能释放率大幅度下降,降幅分别为45.61%、31.29%,而随着含水率增加至饱水状态,其最大损伤应变能释放率增大幅度较平缓,分别为3.08%、8.80%,表明煤岩破坏剧烈程度并未大幅度增加。研究成果对煤岩矿柱水害预测评价与岩石损伤评估具有一定参考意义。

超声波技术在铼酸铵结晶过程中的应用研究

铼是钼矿中的一种稀散伴生金属,本文介绍了一种在铼酸铵结晶过程中使用超过20 kHz超声波辅助结晶的新技术。经小试及工业验证:利用超声波技术,在超声空化作用下,含铼液结晶过程的结晶率提升约3%,产品75μm粒度通过率达到了100%,晶型有了显著改善;新技术具备能耗低、易操作的特点。该研究在提升铼酸铵生产的产品质量方面具有积极意义。

CO_(2)捕捉技术在船舶减碳中的应用分析及展望

船舶碳捕集技术成为当前减少船舶碳排放的重要解决方案之一。针对短期内减少船舶尾气CO_(2)排放的问题,本文系统梳理了CO_(2)捕捉技术及其在船岸的应用和发展;通过对比分析法得出不同方式的CO_(2)捕捉技术的成熟度及优缺点,并在此基础上深入分析了目前CO_(2)捕捉技术在船舶应用中存在的捕捉效率不高、运行成本较高、政策标准不完善等方面的问题;提出了未来船舶尾气碳捕捉技术发展方向及建议,为商船碳捕集技术的更深入研究和推广应用提供更多思路和参考依据。

高比例新能源系统中各类电网侧储能设施调峰效益对比

储能电站的效益评估是储能大规模发展的关键。对高比例新能源系统电网侧储能的效益进行了全面评估,通过全时段8760 h生产仿真模拟,在保持系统供电可靠性不变的约束下,计算了抽水蓄能、压缩空气、电化学储能等储能电站的容量效益、电量效益,考虑了各类储能电站的运行策略。仿真模拟过程中,以周为节点,计算全年8760 h的系统运行状态,考虑了储能电站的运行效率、机组启停、跨日调节等因素,避免了典型日生产模拟无法模拟储能跨日调节导致的储能容量和电量效益评估失真的问题。最后,以中国西北地区实际高比例新能源系统为研究对象,分析了各种储能对减少火电装机、降低新能源弃电率的作用,研究结果可为中国高比例新能源系统电网侧储能电站的建设提供参考。

光伏固废硅泥用作硅热法炼镁还原剂的可行性研究

目前硅热法炼镁工艺所用的还原剂为硅铁,生产硅铁的能耗占硅热法炼镁工艺总能耗的近四分之一、其成本占总原料成本的60%以上,因此,亟需寻求新的低能耗、低成本还原剂助力炼镁工艺向绿色高效的方向发展。本工作提出利用光伏固废硅泥替代硅铁作还原剂的设想,通过实验验证与成本核算证明了其可行性。将干燥后的硅泥与75#硅铁分别作为硅热法炼镁工艺的还原剂进行测试,结果表明:硅泥中单质硅含量更高,且其粒径远小于75#硅铁,使得硅泥做还原剂的硅热反应还原率提升超过5%,所制备的粗镁中杂质元素含量仅为75#硅铁中的40%~80%。用硅泥替代75#硅铁生产金属镁,每吨粗镁的还原剂成本可降低1000余元,同时伴随其他原料吨镁消耗量的下降和镁品质的提升,为生产企业带来显著经济效益。

基于有机物能源化的自养/异养生物脱氮工艺性能

针对厌氧内循环反应器(IC)-缺氧好氧工艺(AO)的传统硝化反硝化脱氮在高有机碳,高氨废水处理过程中能源回收利用率低,脱氮能耗大的问题,设计了IC高效甲烷化,以部分亚硝化/厌氧氨氧化(PN/A)为主的自养脱氮工艺(CANON)处理该类废水,探讨了工程规模下IC-CANON在能源回收和脱氮过程中的运行特性,并评估了其与传统IC-AO能源回收,脱氮稳定性和能耗水平的差异.结果表明,当IC出水C/N 0.5~1时,CANON工艺氮去除速率(NRR)最高达到0.24kg/(m^(3)·d),总氮去除率(NRE)(76.2%±5%),Anammox最小脱氮贡献率在70%以上.当C/N 1.9~4时,一级AO的NRR最高达到0.14kg/(m^(3)·d),NRE为(89.6%±0.9%).当进水氮负荷(NLR)在0.22~0.32kg/(m^(3)·d)波动下,CANON的NRE和Anammox最小贡献率维持在70%和65%以上.当进水C/N增加到2.2时,CANON中Anammox活性被抑制,NRE从76%下降至45.4%,CANON抗NLR冲击能力较强,抗有机负荷冲击能力较差.一级AO在C/N和NLR分别为0.6~6.6kg/(m^(3)·d)和0.06~0.16kg/(m^(3)·d)波动下,NRE维持在90%左右,对比Canon,AO工艺同时具有较好的抗NLR和有机负荷冲击能力.当CANON工艺NRR达到0.21kg/(m^(3)·d)以上,脱氮能耗为3.5~3.6k Wh/kg N,对比相同进出水条件的AO工艺可以节省(77.8%±1.8%),同时IC能源回收率由62.1%增加至89.2%.

水分对无烟煤破碎行为和研磨能耗的影响

煤中水分赋存形态和含量的变化会改变煤炭物理特性和孔隙结构,进而影响其破碎过程。为研究煤炭所含水分对其破碎行为的影响,以无烟煤为研究对象,利用加装功率测量装置的哈氏可磨仪模拟中速磨煤机内的破碎环境,对不同含水量煤样开展多时间批次的单独与混合破碎试验,并研究水分对煤炭破碎速率、煤粉细度及研磨能耗的影响。试验结果表明:相比于原始煤样,均化浸泡煤样单独破碎时初始粒级物料破碎速率因含水量的增加明显减小,其可磨性指数随水分增加先减小后增大,煤粉细度t10与含水量呈正相关关系。干、湿煤样混合破碎时13.34%含水量样品破碎速率和细粒级物料生成速率远大于相同水分的均化浸泡煤样,且其可磨性指数大于原煤;其他含水量的混配煤样可磨性指数略小于均化浸泡煤样,此差异随含水量增加而变大,而破碎速率和细粒级物料产率与均化浸泡煤样差别较小。经典能量—粒度关系模型可用来表征不同水分梯度样品单独和混合破碎过程,内、外水分不同程度降低了无烟煤抵抗破碎的能力,单独破碎时含水量增加可显著提高能量效率;将含水量参数引入能耗模型,实现对多梯度水分煤样破碎过程的表征。通过探究煤中含水量对煤炭破碎能耗的影响机理,揭示煤炭破碎过程中能量损失方式并为优化煤炭破碎工艺、降低能耗提供理论指导。

基于正交试验的天然气脱硫工艺多目标优化

目的针对天然气净化厂处理含硫天然气时常出现能耗较高、净化气流量较低、脱硫选择性较差等问题,基于Aspen HYSYS流程模拟软件,搭建含硫天然气净化厂脱硫单元稳态模拟模型。方法采用多目标正交试验法与综合频率分析法相结合的方法,以工艺总能耗、净化气流量和选择因子3个指标作为综合评判指标,对脱硫单元的吸收塔塔板数、吸收塔压力、胺液循环量和胺液进料温度4个关键工艺参数进行了优化,确定了脱硫单元工艺参数的最优组合方案,并对优化前后脱硫单元的综合性能进行了对比分析。结果①所搭建的稳态模拟模型能够准确地模拟脱硫单元的运行特性,满足工程应用的要求;②各因素对工艺总能耗的影响从大到小依次为:胺液循环量、吸收塔塔板数、吸收塔压力和胺液进料温度;各因素对净化气流量和选择因子的影响从大到小的顺序一致,均为吸收塔塔板数、吸收塔压力、胺液循环量和胺液进料温度;③脱硫单元关键工艺参数的最优组合为:吸收塔塔板数12块、吸收塔压力5.5 MPa、胺液循环量75 t/h、胺液进料温度28℃;④相较于优化前,优化后的工艺总能耗由11316.54 kW降至9590.61 kW,降幅为15.25%;净化气流量由4164.53 kmol/h增至4175.54 kmol/h,增幅为0.26%;选择因子由1.32增至2.20,增幅为66.67%。结论经过工艺参数优化后,脱硫单元的能耗显著降低,净化气流量得到一定的提升,脱硫选择性得到明显改善。

利用响应曲面法研究垃圾渗滤液的电絮凝处理效果

通过研究不同电流密度、极板间距的单电极电絮凝体系在120 min内对老龄垃圾渗滤液中COD、氨氮的去除效果,基于BBD响应曲面法探究了电流密度、极板间距、反应时间的单独及相互作用,从优化目标污染物去除率与电絮凝体系能耗角度分析电絮凝构建策略。结果表明,电流密度、极板间距、反应时间3个单一因素与COD、NH_(3)-N去除率存在显著相关性,电流密度与反应时间呈正相关,与极板间距呈负相关,3个因素两两交互对COD、NH_(3)-N的去除影响不显著。在极板间距5.5 cm、电流密度80 mA·cm^(-2)、反应时间120 min的运行条件下目标污染物去除率最大,COD为87%,NH_(3)-N为86.5%。从安全、经济、环境多方面综合考虑,在长时间、低电流密度和短时间、高电流密度这2个电絮凝构建体系下可实现污染物高效净化及电解池体系低能耗。