COMPUTER DECOUPLE CONTROL OF TEMPERATURE AND HUMIDITY IN PREPROCESSING CHAMBER OF AIR-CONDITIONING TEST EQUIPMENT

This paper deals with the application of decouple Control theory to temperature and humidi-ty control in air-conditioning system. The decouple control algorithm for bivariable systems isderived applicablly for air-conditioning system. The algorithm is used to design a temperatureand humidity computer control system for the preprocessing chamber of air-conditioning testequipment. The results of the real-time control experiments indicate that the decouple controlalgorithm is feasible, the control quality is improved and high control precision is achieved.

PRELIMINARY STUDY OF INDOOR FEATURES OF TEMPERATURE AND HUMIDITY FOR ROOMS FACING NORTH-SOUTH IN WINTER IN A LOW-LATITUDE PLATEAU CITY

Analyzing observations of wintertime air temperature in both indoor and outdoor surroundings in Kunming, a city lying in low latitudes, characteristics of temperature and humidity have been studied for the interior of rooms facing north-south under different weather conditions. Significant warming effect has been identified in terms of lowest and daily-mean indoor temperature in the area of Kunming. The heating amplitude ranges from 7.7C to 10.0C and from 4.6C to 5.8C for the interior part of rooms facing the south and from 4.6C to 7.0C and from 1.3C to 4.4C for the interior part of rooms facing the north, respectively for the two elements. The highest air temperature is higher indoor than outdoor for rooms facing the south, but otherwise is usually true for rooms facing the north. Additional findings point out that buildings not only help maintain relatively warm indoor temperature but delay its variation. The diurnal cycle of temperature indoor is smaller and ranges by 40% ~ 48% for south-facing rooms, and by 20% ~ 30% for north-facing rooms, than outdoor, and the highest temperature is about 2 hours late inside the room than outside. It shows how inertly indoor temperature varies. The work also finds that relative humidity is less indoor in southward rooms than in northward ones and difference is the largest on fine days but the smallest when it is overcast. For the diurnal variation, the indoor relative humidity is large at nighttime with small amplitude but small during daytime with large amplitude. The above-presented results can be served as scientific foundation for more research on climate in low-latitude cities and rational design of urban architectures.

Wireless sensing system for environmental humidity and temperature monitoring

Aiming at the actual demand for monitoring environmental information,a wireless sensing system for temperature and relative humidity(RH)monitoring based on radio frequency(RF)technology and mobile network was designed.This paper introduces the architecture of the system.The system uses AVR micro controller unit(MCU),KYL-1020U RF module and SHT71 to complete real-time temperature and humidity monitoring,and uses SIM900A module to realize remote alarming and monitoring with short message system(SMS)through global system for mobile communication(GSM).Experimental results show that the designed system has good stability of measurement and real-time performance,and it can be used in some small temperature and humidity monitoring occasions.

Impact of Thickness of Polymer Electrolyte Membrane and Gas Diffusion Layer on Temperature Distributions in Polymer Electrolyte Fuel Cell Operated at Temperature around 90℃

Polymer Electrolyte Fuel Cell(PEFC)is desired to be operated at temperature around 90℃ for stationary applications during the period from 2020 to 2025 in Japan.It can be expected thinner polymer electrolyte membrane(PEM)and gas diffusion layer(GDL)would promote the power generation performance of PEFC at this temperature.The aim of this study is to understand the impact of thickness of PEM and GDL on the temperature profile of interface between PEM and catalyst layer at the cathode(i.e.,the reaction surface)in a single PEFC with an initial operation temperature(Tini).An 1D multi-plate heat transfer model based on temperature data of separator measured using thermograph in power generation process was developed to evaluate temperature of the reaction surface(Treact).This study investigated the effect of Tini,flow rate and relative humidity of supply gas on Treact distribution.The study finds that when using thin GDL,the even distribution of Treact – Tini is obtained irrespective of thickness of PEM,Tini and relative humidity conditions.Treact – Tini using Nafion 115 is higher than the other thin PEMs irrespective of Tini and relative humidity conditions.It can be concluded that the even temperature distribution could be achieved by using thin PEM and GDL.

STUDY OF THE HEAT AND HUMIDITY TRANSFER PROCESSES BETWEEN AIR AND WATER IN THE AIR WASHER

The processes of heat and humidity transfer between air and water are what to be studied mainly in the paper, we put forward some main factors which influence the processes of heat and humidity transfer in the air washer. We come to the conclusion that we can change these main factors to achieve different heat and humidity transfer processes and decide processes of heat and humidity transfer of air and water with the initial temperature of spraying water in the air washer. All these results can make things convenient for the air conditioning management.

Numerical Analysis of Temperature Distributions in Single Cell of PEFC by Heat Transfer Model Considering Vapor Transfer

Polymer Electrolyte Fuel Cell(PEFC)is required to be operated at temperature at 100℃ for fuel cell vehicle applications during the period from 2020 to 2025 in Japan.It is expected that micro porous layer(MPL)and thinner polymer electrolyte membrane(PEM)would enhance the power generation performance of PEFC at this temperature.The key objective of this study is to analyse the impact of MPL and thickness of PEM on the temperature distributions of interface between the PEM and catalyst layer at the cathode(i.e.,the reaction surface)in a single PEFC.A 1D multi-plate heat transfer model,considering vapor transfer,which is based on temperature data of separator measured using thermograph in power generation process.It is developed to evaluate temperature at the reaction surface.This study is investigated the effect of flow rate and relative humidity of supply gases on temperature distribution on reaction surface.The study reveals that the impact of flow rate of supply gas on temperature distribution on reaction surface is smaller with and without MPL.It is observed that the even temperature distribution on reaction surface as well as higher power generation performance can be obtained with MPL irrespective of thickness of PEM and relative humidity conditions.

基于机器学习的不同环境条件下松散回潮水分变化的预测

目的明确温湿度对松散回潮工序水分变化量的影响。方法使用K-means聚类分析法划分张家口市环境温湿度区间,利用梯度提升决策树筛选松散回潮水分变化量相关的工艺参数作为特征变量,构建不同温湿度区间下松散回潮工序水分变化量的机器学习预测模型,同时探究车间温湿度对水分变化量的影响,并对最终模型进行优化。结果根据外界环境全年的温湿度,可划分为低温中湿、中温低湿、高温高湿、中温中湿4个区间,且中温低湿与高温高湿区松散回潮工序水分变化量的差异最为显著;分别对中温低湿和高温高湿区构建松散回潮工序水分变化量的LSR、SVR、DT、RF预测模型,综合对比可知,SVR、RF预测模型的精度最高;将车间温湿度作为特征变量后,松散回潮工序水分变化量SVR、RF模型的预测精度均有所上升,其R^(2)'(R^(2)与1的差值)分别降低了25%、46%,说明车间温湿度对松散回潮工序水分变化量的影响较大;对中温低湿和高温高湿区SVR、RF松散回潮工序水分变化量预测模型进行优化后,最终模型的R^(2)'分别达到0.08、0.04。结论松散回潮水分变化量受到外界和车间温湿度的影响,根据不同温湿度区间构建的中温低湿RF模型和高温高湿SVR模型对水分变化量的拟合效果较好,预测准确,能够可靠地应用于松散回潮工序水分变化量的预测,且可拓展用于纸质卷烟包装材料的水分预测和控制,对提升烟丝的卷接包装质量具有重要的理论意义和实际应用价值。

温湿度条件对六堡茶安全贮藏的影响及孢子计数法的应用

研究了温度35、30、25℃,湿度90%、80%、70%条件下六堡茶含水量变化及霉变情况,分析了温湿度对六堡茶含水量及霉变情况的影响,确定了六堡茶易霉变的温湿度条件;优化了孢子计数法应用于六堡茶的方法参数并评估了其在预测六堡茶霉变程度的可行性。结果表明,温度低于25℃,湿度低于70%是六堡茶防止霉变的最优贮藏条件;孢子数量增长水平与霉变程度具有同步性,此方法应用于快速评估六堡茶霉变情况是可行的,且初步确定发生霉变的孢子数临界值为30.00×10^(7)个/g。结果为确定六堡茶的安全贮藏条件提供了依据,为其霉变程度的快速评估提供了可供参考的新方法。

新型智能化纺纱车间环境的优化措施

针对智能化纺纱车间规模大、自动化程度高、生产集约化、发热强度高的特点,提出了优化新型智能化纺纱车间环境的系列策略和措施。分析了影响车间温湿度、气流组织、空气清洁度的因素。通过采取稳定各工序半成品回潮率,提高空调除尘设备能效,强化均匀送吸风等,采用细纱车间热分流、热转移、除尘空调系统低能耗联动等方法,实现了对纺纱车间环境的优化,并配备完善的火灾自动报警和自动灭火系统,保持了车间环境的安全。认为:纺纱车间环境优化的实施可以满足新型智能化纺纱生产线的高效、绿色生产。

杭州国家版本馆恒温恒湿空调系统设计

介绍了恒温恒湿库房空调系统的设计,提出了可在库房建成初期、运行稳定期、战时等灵活切换的3种运行模式,分析了其各自的处理过程与节能性;给出了平、战时空调系统选择方案,提出了平时回收空气源热泵机组和冷水机组的冷凝热作为再热热源,战时利用新风预冷实现温湿度独立控制的方法;利用CFD模拟对室内气流组织进行了优化设计;提出了采用含湿量控制代替定露点法进行湿度控制和风机变频等控制策略。通过调试与运行,证明了各项设计措施在项目中应用的有效性。

钢桥表面相对湿度的边界条件计算方法

表面相对湿度是决定钢桥腐蚀速度的重要因素,精确计算表面相对湿度的关键在于选取合适的温度场边界条件,因此进行了拱肋模型相对湿度测试试验,利用有限元分析软件ABAQUS的DFLUX与UVARM子程序实现了钢桥表面相对湿度计算,并对比分析了不同太阳辐射、辐射换热及对流换热的计算方法对钢桥表面相对湿度模拟结果的影响。结果表明:太阳辐射强度对表面相对湿度的影响主要集中在日出、日落时段,采用Hottle模型计算的日总太阳辐射偏大,导致表面相对湿度偏低,建议使用实测太阳辐射数据计算太阳辐射热流密度;天空及地面的辐射换热对表面相对湿度的影响不容忽视,利用简单的大气辐射换热替代天空、地面辐射换热,会导致结构吸收热量增加,表面相对湿度显著减小,建议在计算辐射换热热流密度时考虑天空温度、地面温度的影响;白天对流换热对结构有降温作用,促使表面相对湿度升高,夜晚对流换热作用对结构有升温作用,促使表面相对湿度降低,目前对流换热系数计算方法多基于混凝土结构开展,后续可进行适用于计算钢桥表面相对湿度的对流换热系数研究。

温湿度箱不同湿度条件下温度分布实验研究

通过对温湿度箱不同湿度条件下温度均匀性的实际测量,可以确认温湿度箱在相同的温度下,湿度不相同,可导致温度均匀性不相同。同时,可以证实湿度越低,温度均匀性越差,湿度越高,温度均匀性越好,并从热传导角度,分析了不同湿度条件对温度均匀性产生影响的原因。

某安保中心数据机房空调系统设计

基于北京市某安保中心数据机房空调系统设计,介绍了数据机房室内温湿度的设计要求及空调负荷计算方法。分析了水冷冷水系统及自然冷却风冷冷水系统两种空调冷源形式的特点及优缺点并对A级机房应急冷源的设计进行了介绍。分析对比了数据机房封闭冷通道及封闭热通道的优缺点及适用性,通过气流组织分析模拟验证了封闭冷通道送风可使冷、热通道内的温度达到设计要求。针对空调冷冻水系统,提出了确定空调冷冻水供回水温度的方法,介绍了能够保证空调水系统安全运行的管路设计方法。总结了数据中心空调节能设计措施,指出了设计时应注意的事项。

北京某宾馆改造采用辐射空调制冷效果分析

国内辐射空调技术应用于新建住宅、办公建筑的实例较多,应用于改造项目的实例较少。北京某宾馆改造采用了辐射+新风的空调系统形式,空调末端采用吊顶辐射板+地面辐射盘管+顶送风,冷热源采用空气源热泵,制冷工况时空气源热泵供出的低温冷水一部分进新风机组,另一部分进辐射用混水设备。2022年7月对项目的空调系统制冷工况进行了测试。给出一定运行策略下宾馆典型房间的温湿度,以及整个制冷系统能效的实测情况,并对典型房间的冷负荷进行了模拟计算。综合测试及模拟计算结果,给出系统运行建议,并对其整个空调季制冷系统能耗指标进行了预测。

微波组件用万级超净车间空调工程设计

该工程项目为微波、毫米波多芯片组件研制车间工程。为满足组件的高性能、高可靠性等技术要求,组件的装配环境是必须前提,必须建造万级超净车间。项目针对现有建筑的特点进行改造,运用温湿度独立控制系统(THIC)技术、下更换式风机过滤单元(FFU)安装技术、洁净实验室全自动化控制系统等技术,设计并建成1 000 m^(2)超净智能车间。可为类似工程设计提供一定的指导作用。

不同温湿冻融循环条件下粉土剪切特性试验研究

为了探究不同温湿条件下冻融循环作用对压实粉土剪切特性的影响,以郑州黄泛区粉土为研究对象,在-5~5℃和-15~15℃温度幅值冻融循环条件下,对含水率为6.0%、10.0%、14.0%、18.0%以及饱和含水率下的压实粉土试样进行冻融循环,并进行剪切特性试验及微观结构分析。结果表明:冻融循环过程中,压实粉土颗粒间的接触方式、排列组合和孔隙特征发生改变,抗剪强度呈先降低后逐渐趋于稳定趋势;由于土中水发生相变和颗粒间作用力发生变化,土样含水率越大,冻融温度幅值对土样剪切强度及其强度参数衰减作用越明显;相同温度幅值条件下,由于颗粒面胶结以及孔隙间水膜润滑的综合作用,冻融循环过程中压实粉土含水率越高,抗剪强度及黏聚力衰减比例越小,内摩擦角衰减比例越大。

某数据中心机房空调系统测试分析及优化措施

以某数据中心机房为例,通过对数据中心机房内空调系统运行时的温度、湿度、风量进行测试,对其测试方法及测试结果进行分析,总结了该数据中心机房空调系统存在的问题,并根据测试结果提出优化改进措施。提出了恒湿机选型及空调选型时需注意的问题以及推荐的风量测量方法,为今后数据中心的设计、运维提供一定的参考。

滨海发射场火箭整流罩空调控制策略研究

直流式整流罩空调在夏季高温、高湿、高盐雾环境中,存在制冷量有台阶、热工影响因素多、受环境影响大、响应特性差等问题,对此展开分析,提出了比例积分微分(Proportion-al Integral Derivative,PID)控制、温湿度解耦、制冷量台阶处理等空调控制策略,并对其进行试验验证,结果表明该措施有效。采用该控制策略对航天器进行环境保障,满足航天器对火箭整流罩内的温湿度要求。

基于灰色预测算法的中央空调温湿度自适应控制方法

为了提升中央空调的控制性能、降低能耗,提出一种基于灰色预测算法的温湿度自适应控制方法。通过灰色预测算法预测中央空调的温湿度数据;采用双模糊PID控制器设计,将温度和湿度的预测结果与设定结果之间的误差及误差变化率作为输入参数,得到实际的中央空调温湿度控制量,实现温湿度的自适应控制。测试结果表明,该方法的温湿度数据预测平均误差小于0.25,控制性能良好,并且温湿度的控制结果与设定结果较为吻合,同时也能降低能耗。

某住宅小区温湿度独立控制空调系统设计

以南京某住宅项目为例,介绍了该项目复合式地源热泵系统、空调水系统、新风系统、空调末端、温湿度及防结露控制。该空调系统采用集中冷热源、分户换热系统,节省了管网投资,降低了输送能耗。用户侧定压补水采用竖向分区减压补水,控制用户侧毛细管系统工作压力,提高了毛细管辐射末端可靠性及使用寿命。置换新风系统采用局部微降板埋地处理,以节省户内空间。其竖向分区的新风系统减小了户内风井面积,增加了使用面积,由双冷源深度热回收新风机组集中回收排风能量,优化了冷凝器配置,热泵回收低温排风能量,提高了内置热泵效率。该项目系统设计对住宅毛细管辐射系统设计具有一定的参考价值。