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随着电网安全可靠性要求的不断提高,油浸式配电变压器过载性能亟待提升。在对混合绝缘系统和常规绝缘系统油浸式配电变压器的耐热等级和温升限值进行分析的基础上,采用热点温度模型评估不同绝缘系统油浸式配变的过载能力,给出了混合绝缘系统油浸式配变的结构调整建议,并进行了成本对比。结果表明,采用耐高温的DPE绝缘纸取代普通纤维素纸,可将油浸式配电变压器过载能力由1.34倍提升至1.53倍,相应成本只增加1.1倍,具有很强的实用性和经济性。 相似文献
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天然酯绝缘油的属性与矿物油相比,在安全性、环保性和对变压器运行方面的优势和缺点广受议论.回顾标准、测试的现状和天然酯绝缘油在电力行业高压变压器的应用,重申ASTM标准规范,新的IEEE指导值和推荐均被检测,并与矿物油标准比较,同时也介绍了IEC规范发展的现状和天然酯绝缘油市场经济发展的需要. 相似文献
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传统配电变压器重过载预警方法主要基于确定性的预测,容易忽视由于负荷不确定性带来的风险影响。针对该问题,提出计及负荷不确定性的配电变压器重过载风险预警方法。首先,采用门控循环单元分位数回归算法预测配电变压器在不同分位点上的负荷水平,并结合核密度估计方法进一步得到未来负荷的概率密度函数,以提供反映负荷不确定性的预测信息;其次,通过效用函数描述配电变压器承受重过载事故的严重程度,结合电力系统风险理论,评估配电变压器可能面临的重过载风险水平;最后,根据预先定义好的标准划分重过载风险等级,进而生成涵盖风险详情的告警信息。结合广东省某地区配电网展开具体的算例分析,验证了所提方法的可行性和有效性。 相似文献
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我厂受沈阳变压器研究所的委托,试制成功了SFSZ_8—31500/110油浸式电力变压器。该产品是沈阳变压器研究所根据原机电部指示,于 1992年7月至 11月由21个厂 29名次设计人员设计的110kV级双绕组无励磁调压变压器和三绕组有载调压变压器两个系列22个品种66个规格中容量最大的一台变压器。 这次设计的两大系列变压器,简称为110kV级 8型油浸式电力变压器。 110kV级8型两大系列产品技术性能优于国内目前运行的同类产品,与现行GB6451.4—86《三相油浸式电力变压器技术参数和要求110kV级》标准比较,空载损耗平均下降22.5%,空载电流下降33.7%,总重量比目前生产的 7型产品下降 28.6%(17.393t)。 我厂试制的SFSZ_8- 31500/110油浸式电力变压器与7型同类产品比,空载损耗下降24.5%,空载电流下降46.4%、该台产品投入电网后,全年可节电约 10.77万 kWh,节能效果显著。 相似文献
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电力变压器应用热管强化散热 总被引:3,自引:0,他引:3
电力变压器应用热管强化散热承德石油高等专科学校段马力,徐钟灵,刘铁铮一、前言对于在用的役龄较长的老式油浸式电力变压器,在不改变其主要结构和保证其安全经济运行的前提下,采取技术措施强化冷却散热,使其在额定容量不变的情况下降低运行工作温升,可以延缓内部线... 相似文献
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1前言 6kV、10kV级配电变压器是企业极为重要的电气设备,它不仅输送电能,自身也消耗电能。由于变压器运行仅为工业生产配套服务,不能产生直接的经济效益,因而,其电能损耗产生的经济损失常常不被人们所重视。S7型配电变压器是80年代初设计投产的一种变压器,至今已有近20年的推广历史,使用者很少对其能耗问题进行分析。特别是有的用户仍在选用或使用S7型配电变压器,而国家有关部门早已作出了关于淘汰S7型配电变压器的规定。S0型配电变压器是一种新型的节能变压器,是目前国内经济技术指标较先进的油浸式变压器。… 相似文献
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为获得某新型推力轴承在某船用轴流压气机中的工作特性并进行试验验证,基于ARMD Bearings软件及自编程序对推力轴承特性进行了模拟计算,在全尺寸高速大推力滑动轴承试验台上进行了轴承特性试验研究,并在实机台架试验中对轴瓦温度进行了监测。计算分析了15种工作条件下油膜的压力、厚度、温度、刚度、阻尼及能量损失与推力和转速关系。轴承特性试验主要包括9种稳定工况下的性能试验,以及轴承超载、超速试验中每块轴瓦表面温度及油膜压力的测量。结果表明:模拟计算结果及试验测试得到的油膜温度、压力随推力及转速变化规律基本一致;轴瓦表面最大油膜压力位于支承块背部附近,与推力基本呈线性关系;转子转速越低、推力越大,则油膜厚度越小、油膜刚度及阻尼越大;转子转速越高、推力越大,则油膜温度越高、能量损失越大;在设计点轴承运行参数均有一定安全裕度,该推力轴承可以满足机组使用要求。 相似文献
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The present study tries to explore the potential of three different types of biodiesel viz. Rice bran oil methyl ester (RBME), Pongamia oil methyl ester (PME) and Palm oil methyl ester (POME) as pilot fuels for a biogas run dual fuel diesel engine designed for power generation. The results indicated that under dual fuel mode, RBME-biogas produced a maximum brake thermal efficiency of 19.97% in comparison to 18.4% and 17.4% respectively for PME-biogas and POME-biogas at 100% load. The emission study divulged that under dual fuel mode, on an average, there was an increase of CO emission by 25.74% and 32.58% for PME-biogas and POME-biogas, respectively in comparison to RBME-biogas. Furthermore, on an average, the HC emissions for PME-biogas and POME-biogas increased by 11.73% and 16.27%, respectively in comparison to RBME-biogas. On the other hand, on an average, there was a decrease in NOX emission by 5.8% and 14%, respectively for PME-biogas and POME-biogas respectively in comparison to RBME-biogas. 相似文献
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Nanorefrigerants are a special type of nanofluids which are mixtures of nanoparticles and refrigerants and have a broad range of applications in diverse fields for instance refrigeration, air conditioning systems, and heat pumps. In this paper thermal–physical properties of nanoparticles suspended in refrigerant and lubricating oils of refrigerating systems were reviewed. The effects of nanolubricants on boiling and two phase flow phenomena are presented as well. Based on results available in the literatures, it has been found that nanorefrigerants have a much higher and strongly temperature-dependent thermal conductivity at very low particle concentrations than conventional refrigerant. This can be considered as one of the key parameters for enhanced performance for refrigeration and air conditioning systems. Because of its superior thermal performances, latest up to date literatures on this property have been summarized and presented in this paper as well. The results indicate that HFC134a and mineral oil with TiO2 nanoparticles work normally and safely in the refrigerator with better performance. The energy consumption of the HFC134a refrigerant using mineral oil and nanoparticles mixture as lubricant saved 26.1% energy with 0.1% mass fraction TiO2 nanoparticles compared to the HFC134a and POE oil system. 相似文献
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为研究不同绝缘纸样在植物油中的老化行为,对FR3植物油与菱格点胶纸、DPE纸和Nomex纸构成的油纸绝缘组合,在130℃环境中开展人工加速热老化试验,测量绝缘纸在10-1~107 Hz范围内的频域介电谱(FDS),分析FR3植物油中绝缘纸样老化前后的tanδ、复介电常数实部ε′和虚部ε″,利用扫描电子显微镜观察绝缘纸的表面微观结构,并测试各纸样的拉伸强度。结果表明,三种纸样在低频下的介电谱随老化程度延长呈现降低趋势,下降幅度为点胶纸>DPE纸>Nomex纸;热老化破坏绝缘纸紧密的纤维排列结构,使其孔洞、裂纹增多;相同老化时间下DPE纸纤维结构比点胶纸纤维结构的劣化程度低;Nomex比点胶纸和DPE纸抗热老化能力更强,机械强度更稳定。 相似文献
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Floating residue (FR), a surplus by-product from the alginate extraction process, contains large amount of cellulosic materials. The technical feasibility of FR utilization as a resource of renewable energy was investigated in this paper. The production of yeast-fermentable sugars (glucose) from FR was studied by dilute sulfuric acid pretreatment and further enzymatic hydrolysis. Dilute sulfuric acid pretreatment was conducted by using sulfuric acid at concentration of 0, 0.1, 0.2, 0.5 and 1.0%(w/v) for 0.5, 1.0 and 1.5 h respectively at 121 °C. The system of enzymatic hydrolysis consisted of cellulase and cellobiase. Results showed that FR might be a perfect bioenergy resource, containing high content of cellulose (30.0 ± 0.07%) and little hemicellulose (2.2 ± 0.86%). The acid pretreatment improved the hydrolysis efficiency of cellulase and cellobiase by increasing the reaction surface area of FR and enhanced the final yield of glucose for fermentation. The maximum yield of glucose reached 277.5 mg/g FR under the optimal condition of dilute sulfuric acid pretreatment (0.1% w/v, 121 °C, 1.0 h) followed by enzymatic hydrolysis (50 °C, pH 4.8, 48 h). After fermentation by Saccharomyces cerevisiae at 30 °C for 36 h, the ethanol conversion rate of the concentrated hydrolysates reached 41.2%, which corresponds to 80.8% of the theoretical yield. It indicates that cellulose in seaweed processing wastes including FR is easily hydrolyzed to produce glucose in comparison with that in terrestrial plants. FR shows excellent prospects as a potential feedstock for the production of bioethanol. 相似文献
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地电流对电力变压器影响研究 总被引:1,自引:1,他引:0
介绍了对南方电网和华东电网在直流输电系统以单极大地回路方式运行时直流接地极地电流对电力变压器的影响以及缓解措施的调查情况,并对接地极地电流对电力变压器的影响进行了分析研究,提出应根据实际运行情况采取合适的保护措施。 相似文献