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基于红外成像技术的电气设备外部热故障在线检测与诊断 被引量:4
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作者 曹海洋 王宏震 李清川 《煤矿机械》 北大核心 2014年第3期224-226,共3页
介绍了基于红外成像技术电气设备外部热故障在线检测和故障诊断技术。设备故障时主要产生3种发热源:电阻损耗发热、介质损耗发热、铁损发热。采用热检测可以有效判断设备故障。与传统热故障方法相比,红外成像技术能够实现非接触式、远... 介绍了基于红外成像技术电气设备外部热故障在线检测和故障诊断技术。设备故障时主要产生3种发热源:电阻损耗发热、介质损耗发热、铁损发热。采用热检测可以有效判断设备故障。与传统热故障方法相比,红外成像技术能够实现非接触式、远距离、不停电、大面积快速在线检测电气设备的温度变化。结合具体的实测电气设备外部热故障热成像图形,通过合理选择绝对温差法,相对温差法,档案分析法,及时准确地对电气设备进行故障诊断,实现了电气设备安全可靠地运行。 展开更多
关键词 红外成像技术 电气设备 外部热故障 在线检测与诊断
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一种外部热耦合反应蒸馏系统的模拟研究 被引量:5
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作者 高翔 刘伟 +2 位作者 陈海胜 黄克谨 王聖潔 《化工学报》 EI CAS CSCD 北大核心 2012年第2期538-544,共7页
引言 过程强化将不同过程集中到一起,能够降低过程的能耗和设备投资费用。热耦合(heat integra-tion)与反应蒸馏是具有明显经济效益的两种过程强化技术[1-2]。黄克谨等[3]提出了外部热耦合双精馏塔,王芸等[4]进一步将精馏段/提馏段... 引言 过程强化将不同过程集中到一起,能够降低过程的能耗和设备投资费用。热耦合(heat integra-tion)与反应蒸馏是具有明显经济效益的两种过程强化技术[1-2]。黄克谨等[3]提出了外部热耦合双精馏塔,王芸等[4]进一步将精馏段/提馏段外部热耦合结构简化为三换热器结构并应用于乙烯/乙烷和苯/甲苯二元物系的分离, 展开更多
关键词 反应蒸馏 外部热耦合 力学效率 过程设计
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简化外部热耦合双精馏塔的控制与优化 被引量:5
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作者 马江鹏 陈海胜 黄克谨 《化工学报》 EI CAS CSCD 北大核心 2011年第8期2195-2199,共5页
针对具有3个换热器结构的外部热耦合双精馏塔(S-EHIDDiC),提出了一种新型的控制与优化策略。顶部与底部换热器的热负荷能够改变高压精馏塔的回流量和低压精馏塔的上升汽量,因而可以用来控制高压精馏塔塔顶和低压精馏塔塔底的产品质量。... 针对具有3个换热器结构的外部热耦合双精馏塔(S-EHIDDiC),提出了一种新型的控制与优化策略。顶部与底部换热器的热负荷能够改变高压精馏塔的回流量和低压精馏塔的上升汽量,因而可以用来控制高压精馏塔塔顶和低压精馏塔塔底的产品质量。这种控制方法与常规精馏塔的LV控制结构相似。S-EHIDDiC还有多余的决策变量(如进料分流比,高压精馏塔塔压和中间换热器的热负荷),可以对稳态操作进行优化。闭环仿真证明了这种控制结构的可行性,稳态优化也提高了系统的热力学效率。 展开更多
关键词 外部热耦合双精馏塔 控制 优化
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基于状态反馈线性化的IGBT外部热管理 被引量:4
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作者 孙林 孙鹏菊 +2 位作者 罗全明 王绪龙 周雒维 《电工技术学报》 EI CSCD 北大核心 2021年第8期1636-1645,共10页
绝缘栅双极型晶体管(IGBT)的热管理技术能降低其运行时的结温波动,提高器件的可靠性。针对IGBT外部热管理系统中的非线性成分,建立系统的仿射非线性模型。通过引入状态反馈线性化方法对其进行线性化,弥补目前IGBT热管理控制系统设计中... 绝缘栅双极型晶体管(IGBT)的热管理技术能降低其运行时的结温波动,提高器件的可靠性。针对IGBT外部热管理系统中的非线性成分,建立系统的仿射非线性模型。通过引入状态反馈线性化方法对其进行线性化,弥补目前IGBT热管理控制系统设计中缺乏精确数学模型的缺陷。基于线性二次型调节器(LQR)设计一种闭环控制方法,通过调节外部散热条件以平滑IGBT运行时由于负载波动导致的低频结温波动。基于Buck电路进行实验,实验证明,所提算法对负载电流在额定值的60%~100%范围内波动时,能够降低约60%的结温波动,提高IGBT约69倍的寿命。最后,基于小电流注入法在线测量结温,验证了基于模型计算结温的准确性。 展开更多
关键词 IGBT外部热管理 非线性系统 状态反馈线性化 IGBT可靠性
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外部热耦合技术在BTX分离中的应用 被引量:1
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作者 黄英博 黄克谨 +1 位作者 王韶锋 刘伟 《广州化工》 CAS 2011年第9期19-22,共4页
外部热耦合式复合精馏塔将热量从高压塔的精馏段传向低压塔的提馏段,降低了分离操作的不可逆性,从而提高系统的热力学效率,降低系统所需的能耗。目前国内苯/甲苯/二甲苯(BTX)的分离技术仍然与国外先进水平相差很远,主要表现在系统的能... 外部热耦合式复合精馏塔将热量从高压塔的精馏段传向低压塔的提馏段,降低了分离操作的不可逆性,从而提高系统的热力学效率,降低系统所需的能耗。目前国内苯/甲苯/二甲苯(BTX)的分离技术仍然与国外先进水平相差很远,主要表现在系统的能耗高、工艺落后等方面。本文将外部热耦合技术应用到苯/甲苯/二甲苯的分离过程中,并用M athem atica软件对系统的设备投资和操作费用进行了仿真计算。结果表明,使用外部热耦合结构,系统节能幅度可达到37.94%,年度总费用降低达18.84%。 展开更多
关键词 BTX 精馏 外部热耦合 节能
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外部热耦合复合精馏塔的经济性与可控性评价 被引量:1
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作者 张星星 黄克谨 《广州化工》 CAS 2010年第5期219-224,共6页
外部热耦合复合精馏塔系统是一种新型的精馏塔系统,通过操作在不同压力下的两个精馏塔的精馏段和提馏段之间的热传递来提高热力学效率。根据精馏段和提馏段热耦合的相对位置不同,外部热耦合复合精馏塔系统可分为对称型和非对称型两种结... 外部热耦合复合精馏塔系统是一种新型的精馏塔系统,通过操作在不同压力下的两个精馏塔的精馏段和提馏段之间的热传递来提高热力学效率。根据精馏段和提馏段热耦合的相对位置不同,外部热耦合复合精馏塔系统可分为对称型和非对称型两种结构。为便于设计和实现,可用外部换热器替代外部热耦合得到简化的结构。本文以乙烯乙烷物系分离过程为对象,通过对外部热耦合复合精馏塔系统建立了静动态模型,采用四点控制的方法,对三种结构的外部热耦合复合精馏塔的经济性和可控性两方面做了分析,证明了非对称型优于对称型外部热耦合复合精馏塔。同时,对使用外部换热器简化外部热耦合结构的方法提供了理论依据和参考。 展开更多
关键词 精馏 外部热耦合 经济性 可控性
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红外成像技术检测电力设备热故障的应用研究 被引量:2
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作者 吴启卫 《产业与科技论坛》 2015年第10期52-53,共2页
为了实现电网系统的安全性、可靠性、经济性,使用科学的方法进行电力设备检修变得很有必要,采用红外热成像仪作为设备检测方法,使电力设备的检修方式从预防性提升到预知性,能够很好地提高设备运行的可靠性和运行的经济成本。在输变电设... 为了实现电网系统的安全性、可靠性、经济性,使用科学的方法进行电力设备检修变得很有必要,采用红外热成像仪作为设备检测方法,使电力设备的检修方式从预防性提升到预知性,能够很好地提高设备运行的可靠性和运行的经济成本。在输变电设备状态检修试验规程中,红外成像检测都被列为例行试验的内容,由此可见红外热像检测工作的重要性。 展开更多
关键词 红外成像 电力故障 外部热故障 内部故障 技术检测
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两大导火索将打破僵局
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作者 深圳推手 《股市动态分析》 2008年第23期27-27,共1页
又是失望的一周,又是地量之后的地量,本周五沪市400多亿的成交量,创下了近两年的新低!阴跌之下,没有胜者,全输之下的市场,其实已经酝酿了极端之后的物极必反,只是导火索还没有出现。
关键词 导火索 成交量 市场 流通市值 中国建筑 外部热 美元 缺口 管理层 中国外汇储备
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Impact of light-weight external thermal insulation materials on building surrounding thermal environment in summer 被引量:6
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作者 李楠 罗国志 +1 位作者 李百战 黄彦祺 《Journal of Central South University》 SCIE EI CAS 2012年第6期1639-1644,共6页
The method for calculating wall surface heat storage coefficient was introduced,and the coefficients of several common walls with light-weight external thermal insulation materials and the traditional solid clay brick... The method for calculating wall surface heat storage coefficient was introduced,and the coefficients of several common walls with light-weight external thermal insulation materials and the traditional solid clay brick wall were calculated.In order to study the impact of light-weight external thermal insulation materials,a contrasting experiment was carried out between an external insulated room and an uninsulated room in August,2010,in Chongqing,China.The result shows that outside surface heat storage coefficient of the insulated wall is much less than that of the traditional wall.However,during sunny time,the surface temperature of external walls of the insulated room is obviously higher than that of the uninsulated room.In different orientations,due to different amounts of solar radiation and being irradiated in different time,the contrasting temperature difference(CTD) appears different regularity.In a word,using light-weight external thermal insulation materials has a negative impact on building surrounding thermal environment and people's health.Finally,some suggestions on how to eliminate the impact,such as improving the surface condition of the building envelop,and plating vertical greening,are put forward. 展开更多
关键词 surface heat storage coefficient external thermal insulation BUILDING thermal environment building envelop
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Three-dimensional analysis of natural convection in nanofluid-filled parallelogrammic enclosure opened from top and heated with square heater 被引量:1
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作者 Abdullah A.A.A AL-RASHED Walid HASSEN +3 位作者 Lioua KOLSI Hakan F. OZTOP Ali J. CHAMKHA Nidal ABU-HAMDEH 《Journal of Central South University》 SCIE EI CAS CSCD 2019年第5期1077-1088,共12页
A numerical study based on the finite volume method has been performed to study the three-dimension natural convection in a parallelogrammic top side opened cavity filled nanofluid with partially heated square at the ... A numerical study based on the finite volume method has been performed to study the three-dimension natural convection in a parallelogrammic top side opened cavity filled nanofluid with partially heated square at the bottom side.Results are obtained for different governing parameters such as nanoparticle concentration (φ) from 0 to 0.05,inclination angle of the back and front walls (α) from 5° to 75°,Rayleigh number from 10^3 to 10^5,and length of heater changer from 0.1 to 1.The main finding from the obtained result showed that the inclination angle and nanoparticle volume fraction affect the flow structure and enhance the heat transfer. 展开更多
关键词 3D analysis open enclosure partial heating PARALLELOGRAM nanofluids
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External versus Internal Loads of Nutrients of an Urban Eutrophic Tropical Reservoir (Southeastern Brazil)
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作者 Antonio A. Mozeto MarceloMontini +6 位作者 Simone A. Braz Felipe G. Martins Aloisio Soares Marcos Roberto L.do Nascimento Francisco Antonio R. Barbosd Pedro S. Fadini Bias M. de Faria 《Journal of Environmental Science and Engineering(A)》 2012年第5期598-610,共13页
This study aimed to evaluate the external and internal fluxes of nutrients of an urban eutrophic reservoir (lbirit6 reservoir, SE-Brazil). External loads were estimated in the tributaries (Pintados and Ibirit6 cre... This study aimed to evaluate the external and internal fluxes of nutrients of an urban eutrophic reservoir (lbirit6 reservoir, SE-Brazil). External loads were estimated in the tributaries (Pintados and Ibirit6 creeks) through nutrient concentrations and discharge measurements. Using Fick's law, internal loads were estimated in the reservoir from fluxes across sediment-water interface from nutrient concentration gradients between the pore water and the water. The Ibirit6 creek (urban sewage recipient) contributes with 72%-47% of ammonium (NH4^+) and 100%-8% of SRP (soluble reactive phosphorus) of the total quantity entering the reservoir, whereas the Pintados creek (oil refinery effluent recipient) contributions are 20%-19% and 44%-100%, respectively. Despite the high external loads (130 and 2.2 ton-yr^-1 of NH4+ and SRP, respectively), internal loads (average flux of 120 and 2 mg·cm^-2yr^-1, respectively) correspond to 25% of the total external loads which may sustain a high productivity in the reservoir for a long time even if the external loads are controlled. The stocks of ammonium and SRP of the interstitial water (100 cm of sediment) would be released to the water in six years and five months, respectively, The release time would be extremely larger (〉 3,000 years) considering the stocks of total N and bioavailable P. 展开更多
关键词 External and internal nutrient loads biogeochemical assessments Ibirit6 reservoir (SE-Brazil) water quality.
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Improvement of the Pulsed Photothermal Technique for the Measurement of the Convective Heat Transfer Coefficient 被引量:4
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作者 M.Rebay A.Arfaoui +2 位作者 G.Mebarki R.Ben Maad J.Padet 《Journal of Thermal Science》 SCIE EI CAS CSCD 2010年第4期357-363,共7页
The present study concerns the measurement of the convective heat transfer coefficient on the solid-fluid interface by the pulsed photothermal method.This non-intrusive technique is apphed for the measurement of the l... The present study concerns the measurement of the convective heat transfer coefficient on the solid-fluid interface by the pulsed photothermal method.This non-intrusive technique is apphed for the measurement of the local heat transfer coefficients in cooling of a rectangular slab that simulates an electronic component.The heat transfer coefficient is deduced from the evolution of the transient temperature induced by a sudden deposit of a luminous energy on the front face of the slab.In order to draw up the heat transfer cartography by a non-destructive tool, the infrared thermography has been used.Two inverse techniques for the identification of the heat transfer coefficient are presented here.The first one is based on the assumption that heat transfer coefficient remains constant during the pulsed experiment,and the second one considered it variable in space and time.The temporal and spatial evolutions are expressed as a constant heat transfer coefficient(h_0)multiplied by a function of time and space f(x,t).The function f is deduced from the resolution of the conjugated convection-conduction problem,by a control volume technique for the case of thermally thick sample.The results are given for different air velocities and deflection angles of the flow. 展开更多
关键词 pulsed method infrared thermography convective heat transfer inverse method.
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Differences in thermal effects of moxibustion at Zusanli(ST 36) and Hegu(LI 4) on various facial areas in healthy people 被引量:13
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作者 Yiling Yang Laixi Ji +3 位作者 Gaobo Li Xiufang Deng Peisi Cai Ling Guan 《Journal of Traditional Chinese Medicine》 SCIE CAS CSCD 2012年第3期397-403,共7页
OBJECTIVE:To study the effects of temperature on different facial areas by suspended moxibustion at two points,Zusanli(ST 36) and Hegu(LI 4),and probe the phenomena underlying self-regulation in the human body after t... OBJECTIVE:To study the effects of temperature on different facial areas by suspended moxibustion at two points,Zusanli(ST 36) and Hegu(LI 4),and probe the phenomena underlying self-regulation in the human body after thermal stimulation.METHODS:Thirty healthy volunteers accepted moxibustion over Zusanli(ST 36) and Hegu(LI 4),and the order of moxibustion points was randomly determined.Moxibustion method:suspension of moxibustion over Zusanli(ST 36) and Hegu(LI 4) on both sides was performed using an ignited moxa stick stuck in a support for 20 min.Observation method:An infrared thermal image of the face was taken before and after suspended moxibustion using a CK350 medical infrared thermal imaging instrument.Data analysis:A thermal microscopic section view system(TMTSys) was used to analyze the change in temperature in special facial areas.Statistical analysis was carried out using SPSS 14.0 software.RESULTS:Before moxibustion was suspended,the facial thermal image showed a T-shaped thermal area related to the vascular distribution with even temperature and good symmetry on both sides.Suspended moxibustion over Zusanli(ST 36) have a very significant increase in temperature at the forehead,around the nose,at the corners of the mouth,and at the cheeks and lips(P<0.01).Suspended moxibustion over Hegu(LI 4) also have a significant(P<0.05) increase in temperature around the nose,the corners of the mouth,the cheeks,and lips,where has a new high temperature area was formed(P<0.01).Suspended moxibustion over Hegu(LI 4) raised the temperature at the middle point of the lips more obviously than did Zusanli(ST 36) in the same person,(P<0.05).After 10 min of moxibustion over Zusanli(ST 36) and Hegu(LI 4),the change in temperature in the facial area reached its peak value.CONCLUSIONS:Facial infrared thermography of healthy people revealed a T-shaped thermal area reflecting a physiological thermal area.Moxibustion over Zusanli(ST 36) or Hegu(LI 4) raised the temperature in this facial T-shaped thermal area.Hegu(LI 4) led to the formation of a new thermal area in the lips.The time required for moxibustion to regulate human body temperature was 10 min. 展开更多
关键词 MOXIBUSTION Point ST 36(Zusanli) Point LI 4(Hegu) Infrared thermal image
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Quantum discord of thermal states of a spin chain with Calogero-Moser type interaction 被引量:2
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作者 MA XiaoSan QIAO Ying +1 位作者 ZHAO GuangXing WANG AnMin 《Science China Chemistry》 SCIE EI CAS 2013年第3期600-605,共6页
In this paper,we have investigated the effect of Calogero-Moser type interaction on the quantum discord of thermal states of a spin chain.Our results imply that the quantum discord depends on the relative distance bet... In this paper,we have investigated the effect of Calogero-Moser type interaction on the quantum discord of thermal states of a spin chain.Our results imply that the quantum discord depends on the relative distance between the spins,the external magnetic field,and the temperature.By a comparison between the quantum discord and the entanglement of formation,the quantum discord is more robust than the entanglement of formation in the sense that the latter takes a zero value in a large range of the parameters,while the former takes a nonzero value. 展开更多
关键词 quantum discord entanglement of formation Calogero-Moser interactions
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Thermal entangled four-level quantum Otto heat engine 被引量:5
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作者 HE Xian HE JiZhou 《Science China(Physics,Mechanics & Astronomy)》 SCIE EI CAS 2012年第10期1751-1756,共6页
Based on a two-qubit isotropic Heisenberg XXX model with a constant external magnetic field,we construct a four-level entangled quantum heat engine(QHE).The expressions for several thermodynamic quantities such as the... Based on a two-qubit isotropic Heisenberg XXX model with a constant external magnetic field,we construct a four-level entangled quantum heat engine(QHE).The expressions for several thermodynamic quantities such as the heat transferred,the work and efficiency are derived.Moreover,the influence of the entanglement on the thermodynamic quantities is investigated analytically and numerically.Several interesting features of the variation of the heat transferred,the work and the efficiency with the concurrences of the thermal entanglement of different thermal equilibrium states are obtained. 展开更多
关键词 nonequilibrium and irreversible thermodynamics quantum entangled heat engine thermal entanglement
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