机舱热发散控制用通风参数影响的模拟分析

针对船舶机舱发电机组、锅炉等高负荷热源,研究采用空气射流通风技术进行热发散控制。结合机舱的现场条件,建立机舱热发散控制的物理模型,选用计算流体力学的标准k-ε模型作为数值模拟计算模型。采用正交试验法对稳态条件下的送风速度、喷嘴高度、送风温度、送风湿度、排风速度等因素进行了模拟试验分析。试验得出不同通风因素对热发散控制效果影响的显著性大小排序:送风温度、送风速度、喷嘴高度、排风速度。结合试验分析结果提出了热发散通风控制的优方案和考虑节能后再优化调整方案。

一种乘用车引擎冷却风扇电机热保护设计与试验

乘用车引擎冷却风扇电机热保护设计是一个复杂的机、电、热耦合系统,分析、研究这样一个复杂系统,建立系统的数学模型是关键。文章首先介绍直流电机的热累积和热发散系统数学模型,并给出电机过载保护、电机启动过程、堵转保护、短路保护等热保护设计方案,同时设计了热保护环节WphR(S)和设定方法。在文章结尾处,对于电机热保护方案进行试验验证,证明该热保护系统设计合理,运行可靠。

电动机综合保护中过负载保护模型的研究

介绍了微机型电动机综合保护中具有反时限特性的过负载保护模型的原理及算法，分析了负序电流的热效应对电动机发热的影响，并在此基础上给出了电动机热积累及热发散的模型及算法。

舰船舱室防火与烟雾扩散研究

舰船舱室内火灾的危险性不言而喻，有必要对其过程进行详细研究，以便采取相应措施，降低风险。介绍了一种针对舱室火灾及烟雾扩散的计算方法，即首先对火灾的过程进行数学建模，然后针对不同的燃烧条件进行模拟计算，并辅以实验验证，对火灾作出安全评估。

喷镀铜合金的船底防污技术

喷镀金属本不是一项稀罕的技术，以往的喷镀，其熔敷温度一般在100℃以上，这很难对易熔、易燃的材料进行喷镀。而新技术关键在于金属本身的直径极细微，仅为50微米，因此，热发散甚快，不使喷射出来的空气温度上升。用铜、锌合金的黄铜和铜、镍合金的铜镍防腐合金，把船底分成两半，一半喷镀黄铜，另一半喷镀铜镍防腐合金。由于船底的铁板事先涂敷一层使加工面成为砂纸状的特殊涂料，

国医大师吕仁和分期治疗隐匿性肾小球肾炎经验

吕仁和教授认为隐匿性肾小球肾炎初起多无明显症状,临床若仅依靠症状诊治易忽略病情进展,因此,应根据患者整体和局部临床表现,分三期论治本病。早期以祛邪为主,重在发散风热、祛风湿清热;中期扶正与祛邪兼顾,扶正以补益肺、肝、脾、肾为主,兼通活冲、任、督、带四脉,祛邪针对由气滞、血瘀、痰阻、食积、湿热壅滞等病机导致的病理产物,随证用药;晚期非大补不能救其虚,非通利不能解其闭,非软坚不能化其癥,故治以补益亏虚、通利二便、消癥化结、通利血脉。

变频风机在封闭母线强迫风冷系统中的应用

强迫风冷系统的风机及电机的选择与封闭母线的额定电流、导体的截面尺寸、母线运行过程中的发热量以及母线的布置走向等有着密切的关系。在正常条件下,强迫风冷装置是必须长期投入运行的,而强迫风冷系统配置的风机电机功率较大,运行过程中将产生大量电能损耗,本文将重点描述强迫风冷系统加装变频风机后在满足各工况条件需求、节能降耗及保护母线稳定等方面的优势。

Preliminary Assessment of Total Mercury in Bulk Precipitation around Olkaria Area, Kenya

Geothermal power plants are receiving increasing attention as regards the mobilization of mercury （Hg） to the environment. Hg is a trace element that may be present in the geothermal fluid, but due to its volatility, it is transferred mainly into the vapor phase. Hence, it may be mostly discharged to the atmosphere with the non-condensable gases. Olkaria geothermal field hosts 3 geothermal power plants. In this area Hg deposition fluxes have not been studied. Concentrations and wet deposition fluxes of total mercury （T-Hg） were determined from April 2009 to May 2010 at 2 sites in this field. Event-based precipitation samples were collected using fabricated bulk precipitation samplers. Samples were treated according to trace metal protocol and analyzed by cold vapor atomic fluorescence spectrometry （CVAFS）. This paper thus reports the first ever determination of T-Hg concentrations and fluxes in precipitation. The T-Hg concentration in samples ranged from 0.002-0.0602 μg/L at the two sites, however, the volume-weighted mean concentration and wet deposition flux were 0.01974 and 0.02884μg.L^-1 and 0.0167-1.45 μg.m2 during the study period. The annual volume-weighted mean wet deposition fluxes of T-Hg for 2 sites were 13.74 and 19.83 μg.m-2.yr-1 with an average flux of 16.785μg.m-2.yr-1. Hg concentrations and the Hg fluxes in precipitation showed seasonal trends being lowest in the short-rains and highest in the long rains. The concentrations of T-Hg for the 2 sites is negatively correlated with the precipitation depth （r2 = 0.26 ＆ r2 = 0.0065）, suggesting that scavenging of particle-bound mercury from the atmosphere is an important mechanism contributing to mercury in rainwater. Mean Hg concentrations in precipitation at the study sites were comparable to the ranges reported for Canada and the USA by the Mercury Deposition Network （MDN）.

Preparation of diamond/Cu microchannel heat sink by chemical vapor deposition

A Ti interlayer with thickness about 300 nm was sputtered on Cu microchannels, followed by an ultrasonic seeding with nanodiamond powders. Adherent diamond film with crystalline grains close to thermal equilibrium shape was tightly deposited by hot-filament chemical vapor deposition(HF-CVD). The nucleation and growth of diamond were investigated with micro-Raman spectroscope and field emission scanning electron microscope(FE-SEM) with energy dispersive X-ray detector(EDX). Results show that the nucleation density is found to be up to 1010 cm-2. The enhancement of the nucleation kinetics can be attributed to the nanometer rough Ti interlayer surface. An improved absorption of nanodiamond particles is found, which act as starting points for the diamond nucleation during HF-CVD process. Furthermore, finite element simulation was conducted to understand the thermal management properties of prepared diamond/Cu microchannel heat sink.

Numerical simulation of liquid desiccant evaporator driven by heat pump

The standard k-ε turbulence model and discrete phase model (DPM) were used to simulate the heat and mass transfer in a liquid-desiccant evaporator driven by a heat pump using FLUENT software, and the temperature field and velocity field in the device were obtained. The performance of the liquid-desiccant evaporator was studied as the concentration of the inlet solution varied between 21% and 30% and the pipe wall temperature between 30 and 50 ℃. Results show that the humidification rate and the humidification efficiency increased with the inlet air temperature, the solution flow rate, the solution temperature, and the pipe wall temperature. The humidification rate and humidification efficiency decreased with increasing moisture content in inlet air and the concentration of inlet solution. The humidification rate increased substantially but the humidification efficiency decreased as the inlet air flow rate increased. The error between the simulations and experimental results is acceptable, meaning that our model can provide a theoretical basis for optimizing the performance of a humidifying evaporator.

从风论治IgA肾病单纯性血尿

针对IgA肾病单纯性血尿无证可辨的情况,通过分析风邪与IgA肾病二者之间的相关性,从辨病论治、体质舌脉、病机演变、微观辨证及药理研究等方面,浅析从风论治IgA肾病单纯性血尿的合理性。早期外风袭肺,当应用轻扬上升、发散利咽之品,如蝉蜕、僵蚕、金银花、牛蒡子、玄参等以宣发卫气、发散风热;在内风袭肾阶段,可应用钩藤、青风藤、鸡血藤、络石藤、雷公藤等藤蔓类药物以搜风通络、驱散风邪;后期风邪潜于肾络,日久与痰瘀之邪胶着互结,导致络道不畅、络体失养,而肾络又具有迂曲纵横、脉道狭小等特点,易瘀易滞,终至络息成积、肾络癥瘕渐成,此时风邪难除,当应用虫类药以搜风剔络、活血祛风。

关于改型斜旋转轴对称准光腔自由电子微波激射器的一个注记

对作者先前在改型斜旋转轴对称准光腔（ＭＡＱＣＯＲ）自由电子微波激射器方面的工作作一补充，说明改型斜旋转轴对称准光腔回旋微波激射器还有一个重要的优点。

Power generation and heat sink improvement characteristics of recooling cycle for thermal cracked hydrocarbon fueled scramjet

In order to further investigate how much fuel heat sink could be increased and how much power generation could be obtained by using recooling cycle for a regeneratively cooled scramjet,the energy conversion from heat to electricity and the fuel heat sink increase in recooling cycle are experimentally investigated for fuel conversion rate and components of gas cracked fuel products at different fuel temperatures.The results indicate that the total fuel heat sink(i.e.,physical+chemical+recooling) of a recooling cycle is obviously higher than the heat sink of fuel itself,and the maximum heat sink increment is as high as 0.4 MJ/kg throughout the recooling cycle.Furthermore,the cracked fuel mixture has a significant capacity of doing work.The thermodynamic power generation scheme,which adopts the cracked fuel gas mixture as the working fluid,is a potential power generation cycle,and the maximum specific power generation is about 500 kW/kg.Turbine-pump scheme using cracked fuel gas mixture is also a potential fuel feeding cycle.

Application of entransy dissipation based thermal resistance to design optimization of a novel finless evaporator

Entransy has been applied and studied in a broad range of heat transfer optimizations recently. Current study proposes the entransy of evaporators to conduct the optimization of heat exchangers in heating, ventilation, air conditioning and refrigeration systems. A novel finless bare tube heat exchanger was studied using a validated heat exchanger modeling tool. The capacity based optimization and entransy dissipation based thermal resistance were used and compared. The applicability of using entransy dissipation based thermal resistance in this type of heat exchanger optimization has been discussed. It has been demonstrated that minimizing entransy dissipation and maximizing capacity are equivalent to optimizing evaporators with fixed flow rates and different when optimizing evaporators with variable flow rates and the deviation is negligible when heat exchanger capacity is small(~1 k W) and more obvious as heat exchanger capacity increases. Thus entransy dissipation based thermal resistance could be used as an alternative optimization index to capacity for evaporators with fixed flow rate and small capacity evaporators with variable flow rates and should be used individually with capacity as an optimization index for evaporators with large capacity and variable flow rates.

Entransy dissipation/loss-based optimization of two-stage organic Rankine cycle(TSORC)with R245fa for geothermal power generation

Based on organic Rankine cycle(ORC), the two-stage evaporation strategy is adopted to replace the single-stage evaporation to improve the system performance. In order to evaluate the temperature matching of the two-stage evaporation, a theoretical optimization model was established to optimize the two stage organic Rankine cycle(TSORC) based on the entransy theory and thermodynamics, with the ratio of the entransy dissipation rate of the TSORC to that of the ORC as the objective function. This paper aims to illuminate the improving degree of the system performance of the TSORC. The results show that the TSORC enhances the average evaporating temperature, thereby reducing the entransy dissipation rate in the evaporator and the total entransy dissipation rate. The maximal net power output is proportional to the entransy loss rate and inversely proportional to the entransy dissipation rate. However, compared with the ORC, the TSORC can output more power but requires a higher total thermal conductance. Moreover, there exists an optimal intermediate geothermal water temperature(IGWT) to maximize the net power output of the TSORC. The TSORC can be considered in engineering applications.

Thermal stability of luminous YAG: Ce bulk ceramic as a remote phosphor prepared through silica-stabilizing valence of activator in air

Aprototype of YAG： Ce （Y3Al5O12） luminous bulk ceramic as a remote phosphor for white LED illumination was fabricated in air through a strategy of silica addition. With increasing the amount of silica in a specific range, the opaque sample turns to be semi-transparent. The precipitation of crystals is verified to be in pure YAG phase by X-ray diffraction （XRD）. Beyond the limit of silica amount, the dominant phase of YAG crystal is found to coexist with a small amount of newly-formed Y2Si2O7, Al2O3 and the amorphous phase. The YAG crystals are with a grain size of approximately 2 μm and distribute evenly. The YAG hosts after structural modification via addition of silica result in yellow band emission of 5d → 4f transition peaked around 535 nm as excited by a blue LED, owing to the self-reduction of Ce^4＋ to Ce^3＋ even in the absence ofreductive atmosphere.

Study on Thermo-Conductive Plastic Finned TubeRadiators

This paper discusses thermo-conductive plastic finned tube radiators used in water saving type powerstations. First, the development of thermo-conductive plastics is introduced. Second, in order todetermine the rational geometric dimensions of thermo-conductive plastic finned tubes, an objectivefunction which takes the minimum volume of the consumed material for making finned tubes as an ob-ject is introduced. On the basis of the function, the economy comparison between thermaxonductiveplastic finned tubes and metal finned tubes is conducted.

Development and Testing of Aluminum Micro Channel Heat Sink

Microchannel heat sinks constitute an innovative cooling technology for the removal of a large amount of heat from a small area and are suitable for electronics cooling.In the present work,Tool Steel D2 grade milling slitting saw type plain milling cutter is fabricated The microchannels are machined in aluminum work pieces to form the microchannel heat sink using the fabricated milling cutter in an horizontal milling machine.A new experimental set-up is fabricated to conduct the tests on the microchannel heat sink.The heat carried by the water increases with mass flow rate and heat input.The heat transfer coefficient and Nusselt number increases with mass flow rate and increased heat input.The pressure drop increases with Reynolds number and decreases with input heat.The friction factor decreases with Reynolds number and decreases with input heat.The thermal resistance decreases with pumping power and decreases with input heat.