The continuous development and increasing availability of Internet of Things (IoT) solutions have led to an era of connectivity in which everyday objects—from household appliances to industrial machines—are connected via the Internet [...]
Nowadays, portable air conditioners (PACs) have gained a broad international market with their advantages of easy installation and flexibility. The water wheel is generally used to solve the drainage problem of the PACs in the high-humidity environment. The reasonable configuration of the water wheel can help extend the continuous operation time and improve the performance of the PACs. This study was built upon existing PACs, exploring the impact of water wheel configurations on the performance of PACs in high-humidity environments. The research revealed that among various water wheel configurations, a dual water wheel configuration functioned better than a single one to help solve drainage problem. And the water wheel configuration that sprays water to the highest temperature area of the condenser proved the most effective for condensate removal. The optimal drainage characteristics of this particular water wheel configuration corresponded to the highest Energy Efficiency Ratio (EER) observed in the PACs, with the maximum increase of 21.11% compared to other water wheel configurations. Additionally, Due to the effect of condensate, with an increase in relative humidity, there was a simultaneous rise in the EER for all water wheel configurations in high-humidity environments.
This paper reviews the stability, heat transfer efficiency and photothermal conversion efficiency optimization studies of solid-liquid phase change materials (PCM) applied to water heaters. Suggestions and prospects were proposed. The study shows that the solid-liquid PCM are mostly filled in the water tank, thermal storage devices or solar thermal collector heater system with paraffin wax, and the addition of solid-liquid PCM can significantly improve the water heater performance. Further in-depth research is needed on PCM dosage and system economics of their application in heat pump water heaters, and the application of photothermal conversion PCM in solar water heater systems.
The advances in the Internet of Things (IoT) and cloud computing opened new opportunities for developing various smart grid applications and services. The rapidly increasing adoption of IoT devices has enabled the development of applications and solutions to manage energy consumption efficiently. This work presents the design and implementation of a home energy management system (HEMS), which allows collecting and storing energy consumption data from appliances and the main load of the home. Two scenarios are designed and implemented: a local HEMS isolated from the Internet and relies on its processing and storage duties using an edge device and a Cloud HEMS using AWS IoT Core to manage incoming data messages and provide data-driven services and applications. A testbed was carried out in a real house in the city of Valparaiso, Chile, over a one-year period, where four appliances were used to collect energy consumption using smart plugs, as well as collecting the main energy load of the house through a data logger acting as a smart meter. To the best of our knowledge, this is the first electrical energy dataset with a 10-second sampling rate from a real household in Valparaiso, Chile. Results show that both implementations perform the baseline tasks (collecting, storing, and controlling) for a HEMS. This work contributes by providing a detailed technical implementation of HEMS that enables researchers and engineers to develop and implement HEMS solutions to support different smart home applications.
Energy behaviours will play a key role in decarbonising the building sector but require the provision of tailored insights to assist occupants to reduce their energy use. Energy disaggregation has been proposed to provide such information on the appliance level without needing a smart meter plugged in to each load. However, the use of public datasets with pre-collected data employed for energy disaggregation is associated with limitations regarding its compatibility with random households, while gathering data on the ground still requires extensive, and hitherto under-deployed, equipment and time commitments. Going beyond these two approaches, here, we propose a novel data acquisition protocol based on multiplexing appliances’ signals to create an artificial database for energy disaggregation implementations tailored to each household and dedicated to performing under conditions of time and equipment constraints, requiring that only one smart meter be used and for less than a day. In a case study of a Greek household, we train and compare four common algorithms based on the data gathered through this protocol and perform two tests: an out-of-sample test in the artificially multiplexed signal, and an external test to predict the household’s appliances’ operation based on the time series of a real total consumption signal. We find accurate monitoring of the operation and the power consumption level of high-power appliances, while in low-power appliances the operation is still found to be followed accurately but is also associated with some incorrect triggers. These insights attest to the efficacy of the protocol and its ability to produce meaningful tips for changing energy behaviours even under constraints, while in said conditions, we also find that long short-term memory neural networks consistently outperform all other algorithms, with decision trees closely following.
功率因数校正(Power Factor Correction,PFC)电路对空调器电流谐波抑制和提高整机功率因数具有重要作用.在空调驱动器高频化、小型化发展趋势下,PFC电路的载频不断提升,目前已达到60 kHz频率,但因PFC电路高频开关导致的传导干扰问题也愈加突出.针对此问题,提出一种干扰抑制方法,通过近场耦合抑制和高频噪声吸收的方式分别对传导干扰中的差模干扰和共模干扰进行处理,降低干扰幅值.并在3匹空调整机进行验证,EMI改善前PFC传导干扰测试曲线最高点平均值相对国家标准余量为0dB,改善后测试余量为11 dB.测试结果符合电磁兼容国标要求,验证了方法的有效性,且方法具有较好的成本优势,适合在空调产品批量应用.
以某一型号滚筒洗衣机悬挂系统为例,首先分别采用多体动力学和线性静态分析方法计算了固定约束工况的滚筒洗衣机外筒强度,并将其计算结果进行了对比和分析.其次,基于多体动力学分析了重力对外筒强度计算结果的影响.最后,利用滚筒洗衣机全模型,校核了外筒、轴、轴承座和三脚架的强度.结果表明:线性静态分析与多体动力学分析得到的外筒最大位移差和最大应力差均随旋转部件转速的增大而增大.重力的考虑使外筒最大位移增大2.70％、最大应力增大1.59％.强度校核滚筒洗衣机全模型得到外筒、轴、轴承座和三脚架的安全系数均在2.5以上.计算得到滚筒洗衣机前/后轴承额定寿命分别为633 h和768 h.
对某款高速风机叶轮在客户端开裂失效的案例进行研究,确认为叶轮动平衡去重策略不当导致失效.目前大部分研究只对如何实现自动动平衡进行论述,而不同动平衡去重策略对叶轮结构影响的研究较少,因此对于研究叶轮动平衡去重策略尤为重要.采用有限元仿真的分析手段,从四种因素分类讨论了叶轮动平衡不同去重策略的优劣性,提出了对于高速风机叶轮理想的动平衡去重策略及优化手段,并通过仿真及实验测试数据的对比验证了理论模型的相对准确性.最后根据理论依据制作对应设备进行叶轮动平衡去重,进一步验证其可行性及有效性,基于该叶轮的风叶外型、基体及材料等因素,得出叶轮切削深度参考范围值为0～1 mm,切削角度参考范围值为30°～45°,宽度参考值为4 mm,偏转角度参考范围值为10°～25°的结论,为高速风机转子系统的叶轮动平衡工艺的改善与管控提供理论依据和应用参考.
英国政府预计延长对英国市场中流通商品CE标志的认可,至2024年12月.相关的更新内容适用于商业和贸易部(DBT)的18项法规. 涉及的产品包括: ——玩具; ——烟火; ——休闲船舶和私人船舶; ——电磁兼容性; ——非自动称重仪表; ——测量仪器; ——计量容器瓶; ——电梯; ——潜在爆炸性环境使用的设备(UKEX); ——无线电设备; ——压力设备; ——简易压力容器; ——个人防护装备(PPE); ——燃气设备; ——机械; ——户外使用设备; ——气溶胶; ——低压电气设备.
根据无线电设备指令(RED)通过授权法案,欧盟委员会(EC)已采取措施,加强欧盟可用无线设备和产品的网络安全.原计划于2024年8月开始实施,现在由于各相关部门围绕标准协调多项工作的推进,该法规的实施已推迟至2025年.因此,从2025年8月1日起,所有在欧盟(EU)销售的无线设备和产品都必须符合RED授权法案的要求.
在某款家用空调室外机项目开发阶段的模拟运输扫频振动实验中,电子膨胀阀出液管根部出现断管现象,通过有限元仿真分析,原方案在77 Hz频率处电子膨胀阀组件存在整体上下模态,是导致断管的主要原因.针对此断管问题,提出了加强管焊接位置的优化方案,仿真得出优化后在实验频率范围内未出现整体上下模态,且在原断管位置处的应力相比原管路方案降低了73.1％.经实验验证,该加强管优化方案有效,可避免该款机型的电子膨胀阀出液管断管问题.
轻工业被定义为产业链中绝对能源使用量低于重工业(如钢铁和水泥)的行业.轻工业的碳排放占所有工业的8％.轻工业的主要组成部分包括:食品生产(占轻工业碳排放的30％)、机械(16％)、纺织品(7％)、车辆(6％)、木材(3％),以及建筑(21％)和采矿(18％).
空气炸锅近年来因其操作简单、安全经济及卫生健康等优点而广受喜爱.其原理是利用高温空气在密闭的炸锅内高速回旋对食物进行加热,但用户为了免清洗而使用一次性油纸,影响了流场均匀性,导致用户在烹饪过程中需要中途翻面.通过在空气炸锅的腔体底部增加发热源来改善用户烹饪中途翻面问题,并应用Fluent软件对空气炸锅的腔体底部温度进行三维数值模拟,获得了腔体底部温度分布情况,分析了发热管均匀盘绕而腔体底部温度分布不均匀的原因,进而对发热管的结构形态改进设计起到一定的指导意义.通过CFD仿真改进及烹饪效果验证得知,增加下发热管,有利于提升底部供热能力,从而达到烹饪中途免翻面效果.
为探究天然缓释剂在冰箱冷藏条件下对典型熟食的保鲜效果,通过对冰箱冷藏室存储的酱牛肉及午餐肉中N-亚硝胺、亚硝酸盐、生物胺、菌落总数等指标进行测定.结果显示,当酱牛肉和午餐肉在4℃贮藏12天后,有缓释剂样品中菌落总数分别比对照组低20.0％和15.79％.由于微生物可以参与亚硝化的化学反应中,菌落总数的减少在一定程度上可以降低4℃贮藏条件下生物胺的积累,抑制酱牛肉和午餐肉在贮藏期间N-亚硝胺的生成.从亚硝酸盐含量推测是缓释剂抑制了亚硝酸盐转化为N-亚硝胺的反应途径.
冰箱门体双轴自锁件由于无固定的旋转轴,可以使得开关门过程中门体不与冰箱侧边物体发生干涉.与单轴自锁件类似,不合理的设计会导致开关门力感体验差或门体闭合不严等问题.针对某款高端类冰箱门体双轴自锁件在关门过程中推门力过大及力感顺畅性差的问题,借助仿真手段得到原始双轴自锁件关门过程中的自锁力,对铰链和助吸器进行结构优化,并仿真分析其可行性,最后制作样件验证其实际效果.结果表明:优化的双轴自锁件在保证门体自闭功能的前提下将关门过程中的最大推门力降低至适中水平,同时提升了力感的顺畅性,为双轴自锁件的设计提供了控制和优化方向.
现有热泵干衣机存在运行噪声高的问题,主要原因在于其离心风机气动噪声过高,作为一款家电产品,运行噪声将直接影响用户体验.通过CFD仿真技术,分析原始风机风道方案的流态,定位运行噪声偏高的原因.基于CFD分析的情况,设计了风机风道优化方案,包括针对性地优化了蜗壳的结构和全新设计离心风机.手板样件实验数据显示,在相同风量下,新方案的风机运行转速降低38.3％、噪声值降低2.91 dB(A).优化分析结果对热泵干衣风机的设计具有指导作用,对相关家电产品的风机设计与优化也具有一定借鉴意义.
目前,市场上推出的高端薄壁冰箱大多使用真空绝热板来降低箱体和门体的发泡层厚度,以达到降低产品耗电量和提升产品容积率的目的.但真空绝热板价格昂贵且易破损,在冰箱制造期间需要采用大量的防护措施.为了提高生产效率、优化成本、提升产品竞争力,提出了取消箱体真空绝热板并在不改变箱体发泡层厚度的前提下仍能达到原状态性能的思路.箱体在取消真空绝热板后势必会增加漏冷量,出现不能达成1级能效、高环温储藏温度不达标、凝露不合格等问题.研究采用理论分析和试验测试的方法,通过提高制冷效率、降低待机功耗、减少箱体门封处漏冷量等方案实施解决.测试结果显示:当取消真空绝热板后整机耗电量增加约8％,通过优化设计后,整机耗电量降低约8％,达成1级能效目标;储藏温度和凝露测试均由不合格改善为合格,最终达成各项性能和可靠性指标.该研究方案给箱体取消真空绝热板提供优化思路,在产品进行性能提升时也可作为参考.
2023年7月13日,巴西国家电信局(ANATEL)公布了第9281号法案,批准了智能电视盒的适用技术和合格评定要求. 这些要求适用于智能电视盒,智能电视盒是一种终端设备,用于通过互联网播放视听内容,并将其显示在另一个带有显示屏幕的设备上.涉及的设备包括:个人电脑、电视、手机、平板电脑和付费电视设备等.
家电强国是我国家电人长久以来追逐的目标.经过40多年的发展,家电产业已经成为国民经济的支柱性产业,年产值超过1.7万亿元,出口超过6000亿元.我国主要家电产品的产销量位居世界第一,其在电器安全、健康化、智能化等方面的质量和技术已达到世界先进水平,但在高端家电性能和可靠性等方面,与国际先进水平仍有一定差距.
相比空气净化器,家用新风机能进一步地排出室内累积的二氧化碳CO2和甲醛、TVOC等化学污染物,带有热交换器的新风机还可以减少热/冷损失,是新兴的室内空净产品.通过试验舱模拟家用新风机的实际工作状态,针对室外污染物颗粒物建立净化性能评价方法;并选用大约30台不同类型新风机机型进行多次测试,同时对约10个型号的同一新风机重复测试,重复试验的偏差在3％以内,通过验证净化效果的一致性证明了方法的可行性.以上结果说明,采用的试验模拟舱及净化性能测算方法可以用于相关产品的性能评价.
