The Application and Simulation of Fuzzy Adaptive PID in Household Heating Metering System

After heat is metered in each house unit,the heating system is regulated by variable flow.The temperature of the return w ater is controlled to regulate the flow to realize the temperature regulation.According to the characteristics of the temperature control w ith big inertia,pure time-delay and degeneration,a fuzzy adaptive PID controller is designed w ith the advantages of the fuzzy control and PID algorithm,and the simulation model is established according to the characteristics of heating metering system.Simulation results show that the fuzzy adaptive PID controller proposed has small overshoot,short oscillation cycle,high precision and strong anti-jamming capability in comparison w ith conventional PID controller,w hich could meet the requirement of the dynamic and steady-state performance of the heating process.

Design of transit-time difference ultrasonic heat meter based on TDC-GP21

According to the transit-time difference measurement method,we proposed a design scheme of ultrasonic heat meter based on TDC-GP21.The measurement unit TDC-GP21 mainly completes transit-time measurement and inlet,outlet temperature measurement functions.Control unit and data processing unit based on MSP430F4152 of TI corporation complete functions including peripherals control,data analysis,temperature compensation algorithm,flow pattern compensation algorithm and low power consumption control.The design meets the Town Construction Professional Standard CJ 128-2007,and furthermore,some performances can be improved.

Study on the Wireless Heat Meters

The design of a new type heat meters based on RFID technology are presented in this paper. By use of RFID technology in heat meters, the data can be exchanged between heat meters and heat supplying department by RF cards. The information can be transmitted in a non-contact way. In this way, the purpose of automatic identification can be achieved. The experimental study of the heat meters is also performed in the paper. The results show that the new type of heat meters can meet the demands of users. Compared with the ordinary heat meters, the new type of heat meters have the advantages of small in meter volume, high accuracy, no impact of water quality and good reliability.

Design and Implementation of an Ultrasonic Heat Meter Based on MSP430F437

Flowing with the reform of the hot water heating method in China, heat meter will enter into households in the near future. A portable ultrasonic heat meter is designed in this paper. The meter uses chip microprocessor MSP430F437 as the data process core, and uses ultrasonic flow sensor to measure flow rate of the hot water, and capture input and output temperatures of the hot water using the thermal resistance sensor Ptl000, and then household energy consumption is calculated via temperature difference between input temperature and output temperature of the hot water multiplied by volume of hot water that is calculated though flow rate integration of hot water. In order to test the performance of the proposed heat meter, experiments is carried out. Both the temperature and flow measurement results satisfy the requirements of accuracy and the heat meter is effective in the heat measurement.

Analysis of heat pulse signals determination for sediment-water interface fluxes

The heat pulse signal is analyzed in a new way with the goals of clarifying the relationships between the variables in the heat transfer problem and simplifying the procedure for calculating sediment-water interface fluxes J. Only three parameters x0 λand pc l are needed to calculate J by the heat pulse data for this analysis method.The results show that there is a curvilinear relationship between the peak temperature arrival time and sediment-water interface fluxes and there exists a simple linear relationship between sediment-water interface fluxes and the natural log of the ratio of the temperature increase downstream from the line heat source to the temperature increase upstream from the heat source.The simplicity of this relationship makes the heat pulse sensors an attractive option for measuring soil water fluxes.

Experimental Research of the Radiator Thermal Performance Test Equipment and Its Application in Heating System

Radiator thermal performance test equipment plays a key role in the processing of developing a new type of heat radiator and its application products.The precise of temperature controlling,temperature measuring andflow measuring are the vital factors for a radiator thermal performance test equipment.Based on the above back-ground,this paper improves the measurement and control system of radiator thermal performance test equip-ment,which improves the accuracy of the radiator thermal performance test equipment.This paper also optimizes the software and hardware system simultaneously so as to improve the precision of the auto-test system of test equipment.Theflow rate ranges from 175 kg/h to 178 kg/h under different conditions.The average is 176.5 kg/h and the deviation rates are from 1.62%to 1.97%.The heat produced under various conditions is different.The maximum is 4.3 kW and the minimum is 4.2 kW for condition 1,the maximum is 3.3 kW and the minimum is 3.2 kW for condition 2 and the maximum is 1.95 kW and the minimum is 1.89 kW for condition 3.However,the deviation rate is about 2.9%,which shows that the device has high stability and high precision.This paper studies a new electronic heat cost allocate meter test method by radiator thermal performance test equipment at the same time.This paper tests temperature changes through four measures points and gets a result appeared as a heat backup which should be avoided when using in the test of electronic heat cost allocate meter.Some experiences and references could be gained for further research in the heating system from this test and research.

Water, Air Emissions, and Cost Impacts of Air-Cooled Microturbines for Combined Cooling, Heating, and Power Systems： A Case Study in the Atlanta Region

The increasing pace of urbanization means that cities and global organizations are looking for ways to increase energy efficiency and reduce emissions. Combined cooling, heating, and power （CCHP） systems have the potential to improve the energy generation efficiency of a city or urban region by providing energy for heating, cooling, and electricity simultaneously. The purpose of this study is to estimate the water consumption for energy generation use, carbon dioxide （CO2） and NOx emissions, and economic impact of implementing CCHP systems for five generic building types within the Atlanta metropolitan region, under various operational scenarios following the building thermal （heating and cooling） demands. Operating the CCHP system to follow the hourly thermal demand reduces CO2 emissions for most building types both with and without net metering. The system can be economically beneficial for all building types depending on the price of natural gas, the implementation of net metering, and the cost structure assumed for the CCHP system. The greatest reduction in water consumption for energy production and NOx emissions occurs when there is net metering and when the system is operated to meet the maximum yearly thermal demand, although this scenario also results in an increase in greenhouse gas emissions and, in some cases, cost. CCHP systems are more economical for medium office, large office, and multifamilv residential buildings.

储热技术研究展望

近年来,储热技术被广泛认为是实现碳中和、碳达峰的一项关键技术备受关注。通过从CNKI、Web of Science等数据库中筛选储热技术相关文献,运用CiteSpace软件进行知识映射,展开系统分析、统计及可视化,绘制出储热技术研究力量合作网络图谱,展示该技术研究力量的分布与科研合作情况。同时针对关键词进行分析,总结储热技术的研究热点、研究前沿及发展趋势,指出相变储热和混合储热模式是未来研究的重点。针对储热材料稳定性差、使用寿命短,有机相变材料成本高、安全性低,系统设备初始造价高、成本回收期长等储热技术现存问题,从政策干预和市场需求角度提出了改进建议。

套管式地埋管换热器节能特性的研究与应用

大庆油田进入开发后期存在着一定数量的废弃井,采用套管式地埋管换热器可以获取到废弃井的中深层的地热能。首先对废弃井转换为地热井的可行性进行分析,通过确定中深层地埋管换热方式,建立外入内出型传热计算模型并对废弃井结构改造。再具体分析大庆油田的地层土壤温度分布和确定边界条件,得出符合现实的理论计算公式。进一步分析套管式地埋管换热器取热评价指标与传热影响因素研究,得到流体流量和进口温度对传热影响因素,及循环流体进口温度对运行特性的影响对取热效率的影响规律。最后,通过对两种工况的废弃井现场试验,得到套管式地埋管换热器平均换热量为478.5 kWh。为利用大庆油田1700口废弃井的节能改造找到了一条切实可行的出路。

基于微型空间相机的红外加热笼仿真与设计

在航天器热控技术领域,常采用红外加热笼模拟各表面的到达外热流,但随着模拟表面特征尺寸的逐渐变小,需要重新评估该模拟方法的合理性和准确性。本文基于某微型空间相机,以对外热流最为敏感的散热面为研究对象,开展红外加热笼仿真分析与优化设计的研究。采用有限元法建立红外加热笼-黑片热流计的系统仿真模型,分析了传统红外加热笼控制方法对模拟表面总到达能量和热流密度均匀性的影响。基于上述结果,通过适当扩大加热笼尺寸和调整热流计粘贴位置,提高模拟表面的热流密度均匀性,保证总到达能量满足保守设计原则。对比分析得出,优化设计前后散热面热流密度的统计方差由102.0下降至27.0、均匀性提升效果显著。本文研究内容也可为其他空间微小表面外热流的准确模拟提供参考、借鉴。

基于平面热源-热流计法确定墙体热阻的影响因素分析

通过试验验证了平面热源-热流计法测试墙体热阻的可行性,并利用ANSYS软件建立墙体二维传热模型,通过模拟计算研究了平面热源加热面积、墙体两侧温差、测点布置和双面加热对墙体热阻值的影响。研究结果表明:墙体冷热侧温差越大,达到稳定传热时间越长,导致热阻值误差更大,建议墙体两侧温差在20℃时进行热阻测试;加热面积从0.3 m×0.3 m增大到1.2 m×1.2 m,使得一维传热区大小从0.11 m增加到0.27 m,热阻值误差降低至0.5%;测试测点应布置在靠近水泥砂浆层的区域;双面加热测试热阻值误差比单面加热低2%。

装配式被动房墙体传热系数测试与能耗模拟

以河北省保定市某装配式被动房为研究对象,采用热流计法对其东、西两侧围护结构主体部位的传热系数进行现场测试。基于测试结果,利用DeST能耗模拟软件模拟该建筑理论计算和实测传热系数下的全年能耗,得出理论计算与实测条件下利用传热系数计算的能耗偏差。结果表明该装配式被动房东、西两侧围护结构主体部位的实测传热系数相比.于理论计算值分别偏高偏差为103%。以期通过传热系数现场测试过程与能耗误差值的范围为今后进一步研究装配式被动建筑提供参考。

百米U75V钢轨在线热处理工艺优化

百米U75V钢轨是我国铁路建设的主型钢轨,在线热处理是其主要强韧化手段,纵向(长度方向)性能均匀性差和生产效率低是其热处理生产存在的主要问题。百米U75V钢轨的在线热处理过程分为2个冷却阶段,共包含4个冷却工艺参数:开淬温度(T_(i))、相变阶段冷却速度(V_(s))、相变冷却结束温度(T_(f))以及相变后冷却速度(V_(a))。通过热模拟试验研究了各参数对百米U75V钢轨组织和性能的影响。随着工艺参数的变化,珠光体片层间距(S)在100.7~209.1 nm范围内变化;T_(i)和V_(s)对S具有特别显著影响,T_(f)和V_(a)对S没有显著影响;T_(i)不一致是百米U75V钢轨纵向性能不均匀的主要原因之一。采用“先慢后快”的两段式冷却方案,即在轧后钢轨表面温度冷却至相变终冷温度(约500℃)之前,以接近但不超过珠光体转变临界冷却速率的速度进行冷却,之后提高冷却速度(不超过10℃/s),有利于同时提高生产效率和百米U75V钢轨纵向性能的均匀性。

热计量仪表在采出水余热利用项目中的应用

采出水余热利用是一种重要的能源回收方式,热计量仪表在采出水余热利用项目中起关键作用。介绍了热计量仪表在采出水余热利用项目中的应用,分析了热计量仪表的分类、选型与安装使用要求,研究了测量误差源,提出了测量误差控制措施。通过介绍,对采出水余热利用项目中热计量仪表的使用、测量误差的减小、测量准确性和可靠性的提高具有参考价值。

热计量供暖用户用热行为的实测与分析

热计量供暖模式下用户的用热行为对供热能耗有着重要影响。为了解我国北方地区热计量用户冬季用热行为现状,采用调研与实地测试相结合的方式,对天津市20个热计量用户的室内热环境、调节供暖末端、开关窗行为进行了研究。结果显示,在热计量供暖模式下用户的用热行为缺乏科学合理性,主要表现为:积极调节用户比例较低;冬季室内温度设定值较高,最高达29.38℃,开窗现象较为严重;热计量供暖的宣传力度不足,15.38%的用户表示“不知道如何调节”供暖末端阀门;温控阀存在调节作用失灵问题。53.85%的用户表示温控阀调节功能差。

集中供热末端调控及分户热计量系统的实现

实现分户热计量收费是我国供热体制改革的主要目标之一,有效的末端调控和合理的计量收费策略,是关系着供热体制改革能否顺利推进的重要因素。给出了一种基于ZigBee技术实现的供热末端调控系统,可根据场所人员活动规律自动进行分区、分时段调控室内温度,节约热力资源,提高供热效率,降低取暖费用。同时,给出了一种按照供热效果进行统计分析的模型,提出了一种改善分户热计量的新方法;以每栋楼的用热总量计算该栋楼的总供热费用,按照用户的供热面积、实际供热效果和用热量相结合,计算每个用户的热效值和整栋楼总热效值,分摊计算出每个用户的取暖费用,使每个用户的取暖费用真实地反映其用热效果。

一种不须停电且无电量损失的电能表更换方法

现有电能表更换技术普遍存在若干问题,实用性较差。为此,文章提出一种实用性很强的电能表更换方法,该方法基本步骤是通过换表线先行并入新表,然后拆离旧表,最后装上新表。该方法具有不须用户停电、不存在电量损失、电量交接简单、绝缘防护完善等优点。

单侧热绝缘热流计校准装置的研制

热流计是量化热能转移的仪器。为解决非对称平面热流计、热流传感器校准的难题,基于绝对法原理,对保护板法进行改进,建立一种单侧热绝缘的热流计校准装置,由主加热器、绝热层、保护加热器、功率输出系统、温度反馈调节系统和数据采集系统组成,装置可溯源至标准功率计。在400~1 000 W/m2范围内对装置进行验证,测试结果与传统保护板法热流计校准装置标定结果基本一致。根据测试结果评估电流源偏差、背向和侧向热损失、蓄热损失、测量重复性、面积不一致、装载方式对测量结果的影响。经过实验和分析,该装置的不确定度可以达到3%以内。

高干热环境下计及竞争失效的电能表可靠性评估方法

典型环境下电能表寿命与可靠性评估是行业内亟待解决的热点和难点问题。针对高干热典型环境试验基地挂网电能表存在样本量小、突发失效和渐进失效并存的问题,在计及故障数据随机截尾的情况下构建了电能表可靠性经典和Bayes评估方法,将现场运行电能表的可靠性信息与高干热典型环境基地电能表的可靠性信息相融合以扩展信息量,提高电能表可靠性评估准确性。进而考虑到电能表计量性能存在多指标、渐进失效的情况,基于多元Wiener过程构建高干热环境下存在竞争失效模式的电能表可靠性综合评估模型,给出电能表可靠度、MTBF和可靠寿命三种可靠性指标的点估计与置信限。收集了新疆吐鲁番、乌鲁木齐和阿勒泰地区现场挂网运行数据和高干热典型环境试验基地内电能表数据,验证本文所提方法的有效性。研究成果不仅为解决了小子样多元竞争失效型产品可靠性评估提供了理论基础,在工程上也为电力计量行业借助典型环境试验基地开展量测设备可靠性评估提供了参考,其应用前景广阔。

基于参数动态解析的热量表通讯方法研究

针对不同企业热量表通讯协议不一致等问题,提出了一套基于参数动态解析的不同企业不同规则热量表通讯方法。通过对不同企业热量表通讯协议的拆解,建立通讯动态解析知识库,创建参数解析公式,可同时动态解析不同通讯规则热量表,解决了不同企业不同规则的热量表同时通讯不兼容的难题,提高了检定检测工作效率。