隧道窑采取的环保措施

板坯连铸速度的提高导致钢水表面波动和结晶器凝固壳厚度减薄.因此,改进了浸人式水口和结晶器保护渣,以满足连铸条件.新开发的结晶器保护渣"REVIX"系列不仅具有弯月面迅速结晶化缓冷的效果,还确保结晶器下部凝固壳厚度充分传热,实现了高速连铸和抑制铸坯表面裂纹的形成.至于浸入式水口,环状阶梯型浸入式水口和凸型浸入式水口可提供均匀的钢水流和抑制夹杂物侵入结晶器深处.     

零触发调功控制在VK管加热控制中的应用

本文针对国内目前VK管采用的二位或调节温控方式进行了分析,指出其温控方面的不足之处,为了进一步提高产品质量把二位式调节温控方式改进为零触发调功控制。通过一年多的实践证明,改进后的VK管各段温度传热均匀,温控精度高,对提高VK管生产的产品质量起到了很大的作用。     

家电彩板表面亮点缺陷分析

采用轮廓仪以及扫描电镜分析了导致家电彩板表面亮点缺陷的因素。结果表明,锌锅中锌渣粘在带钢表面,经过光整轧制后在带钢表面形成细小的凹坑,导致彩涂板生产过程中,辊涂时涂料涂覆不均匀,造成亮点缺陷(即色差)。     

物性参数对连铸结晶器传热模型计算结果的影响

针对某方坯连铸实际情况,建立了二维非稳态传热模型,研究了导热系数、比热和密度对结晶器传热模型计算结果的影响规律.研究结果表明,其他条件一定,导热系数越大,铸坯表面温度下降越缓慢,铸坯中心温度则下降越快;增大密度或比热,出结晶器的铸坯表面中心及铸坯中心温度均增大.相比较而言,导热系数对结晶器内铸坯凝固传热过程的影响最为显著,比热的影响次之,密度的影响最小.     

以天然碱生产重质纯碱结晶设计

介绍了以天然碱为原料制取重质纯碱的结晶设计 ,重点分析了蒸发结晶器的形式、溶液的过饱和度、传热温差、循环型式和流速等因素对产品质量和系统的影响。该蒸发结晶器及蒸发结晶工艺对其它需要提高密度、粒度的产品的生产具有较为普遍的借鉴意义。     

套管结晶器定期除垢强化介质传热效率

105HI型套管结晶器是针对络合反应条件吸收反应热量等特点为尿素脱蜡装置设计的专用反应器。在大温差的换热过程中极易结垢,长时间使用后严重影响换热效果,降低换热效率,同时因热量不均匀而影响产品质量。在相同的生产负荷下,采用定期除垢方法可大幅提高换热效率,增加低温水在结晶器中的停留时间,有利于提高产品质量和收率,大幅降低能耗。     

缩短低温法HPVC树脂反应时间的研究

对低温法生产HPVC树脂的生产工艺进行了改进,解决了釜内外温差小,传热困难,反应温度难以控制,反应时间长,生产成本高等问题。改进后反应时间缩短为7～8h,产品质量稳定。     

以天然碱生产重质纯碱结晶设计

介绍了以天然碱为原料制取重质纯碱的结晶设计，重点分析了蒸发结晶器的形式、溶液和过饱和度、传热温差、循环型式和流速等因素对产品质量和系统的影响。该蒸发结晶器及蒸发结晶工艺对其它需要提高密度、粒度的产品的生产具有较为普遍的借鉴意义。     

高纯石墨镀炭铸锭结晶器制备工艺改进研究

高纯石墨镀炭铸锭结晶器是在原先石墨铸锭结晶器的基础上改进的一种结晶器，它弥补了原结晶器的缺陷，保留了其优点，本文主要介绍了此结晶器的制备工艺流程和其影响因素，说明了其实用特性和范围。     

提高把手喷涂产品成品率的研究

针对客户把手喷涂产品存在表面麻点缺陷,成品率仅为29.41%的问题,本文在生产实践的基础上,分析了产品出现缺陷的具体原因,并对产品质量的改进措施进行了研究。结果表明,产品的缺陷主要是由基材表面的颗粒、夹渣及纹路造成,通过采用喷砂、碱蚀、返喷和化学修复剂修复等措施,可将把手喷涂产品合格率稳定在90%以上。     

聚光式太阳能热发电中传热工质的研究现状

聚光式太阳能热发电系统的传热工质主要包括水／水蒸气、空气、导热油、液态金属和熔盐。针对传热工质的物性·提出了各传热工质的优缺点,介绍了传热工质在太阳能热发电中的应用现状及研究情况,指出熔盐将是未来太阳能热发电传热蓄热工质发展的重点。     

大型注射成型塑料件的温度控制方案

提出把模具看作是热交换器的思想，认为要控制模温稳定，就是要使输入模具的热量与冷却而输出的热量相等。通过控制冷却水的流量和冷却水进出口温差的乘积，并根据环境温度，对上述乘积作适当调整，补偿一部分由空气所带走的热量，向模具输入的热量与模具输出的热量达到动态平衡，从而使生产过程能稳定进行。     

Development of rapid heating and cooling systems for injection molding applications

The injection molding process has several inherent problems associated with the constant temperature mold. A basic solution is the rapid thermal response molding process that facilitates rapid temperature change at the mold surface thereby improving quality of molded parts without increasing cycle time. Rapid heating and cooling systems consisting of one metallic heating layer and one oxide insulation layer were investigated in this paper. Design issues towards developing a mold capable of raising temperature from 25°C to 250°C in 2 seconds and cooling to 50°C within 10 seconds were discussed. To reduce thermal stresses in the layers during heating and cooling, materials with closely matched low thermal expansion coefficient were used for both layers. Effects of various design parameters, such as layer thickness, power density and material properties, on the performance of the insert were studied in detail with the aid of heat transfer simulation and thermal stress simulation. Several rapid thermal response mold inserts were constructed on the basis of the simulation results. The experimental heating and cooling response agrees with the simulation and also satisfies the target heating and cooling requirement.     

Some factors influencing cooling rates of rotationally molded parts

Recently, rotational molding engineers, concerned with warpage and uneven cooling in parts, have been “pre-cooling” the mold in forced draft air after removal from the oven and prior to water quenching to removal temperature. In this paper, we analyze some of the factors that influence the rate of heat removal from an amorphous plastic in a metal mold. We find that mold thickness and thermal diffusivity, convection heat transfer coefficient of the cooling fluid, the thermal properties of the plastic and the initial, final and “freezing” temperatures of the plastic influence this cooling rate and the corresponding rate of volumetric shrinkage. We illustrate our analysis with several examples and discuss some guidelines in detail.     

低熔点熔盐圆管内强迫对流换热

熔融盐具有使用温度高、热稳定性和传热性能好等优点,被认为是太阳能热发电系统中最有前途的传热、蓄热介质之一。通过搭建槽式太阳能熔盐集热传热实验台,进行了低熔点熔盐管内受迫对流换热实验,获得了不同熔盐流速下套管式熔盐-水传热单元的总传热系数;通过最小二乘法获得了低熔点熔盐管内充分发展紊流段对流换热Nusselt数随Reynolds数的变化曲线和实验关联式,并与经典关联式进行了对比,结果表明,实验数据和Dittus-Boelter方程、Colburn方程、Seider-Tate方程以及Gnielinski方程最大偏差分别为+23%、+13%、-10%和-20%,实验数据和经典公式符合较好。     

Improving appearance quality of injection molded microcellular parts through mold coating of PTFE and zirconia

The application of microcellular parts in the field of high appearance quality is limited due to its appearance defects. In order to improve the appearance quality of microcellular parts, low heat transfer coefficient mold coating with PTFE and zirconia was employed in this study. The appearance quality of microcellular was evaluated by the surface roughness of microcellular parts. The numerical and experimental results show that delayed heat transfer between the melt and the mold can be achieved through both mold coatings, which improve the melt fluidity and reduce the shear force of the mold on the melt effectively. It is demonstrated that the PTFE has a better effect of delay heat transfer under thinner coating. The polished zirconia coating shows more conducive to the melt wall slip due to its stable molecular structure and smooth surface, resulting in microcellular parts with better appearance quality.     

蓄热技术在聚焦式太阳能热发电系统中的应用现状

从了解聚焦式太阳能热发电（CSP）的发展背景出发,综述了CSP系统中的蓄热技术的应用现状与发展方向,对各种蓄热技术进行了比较,并简要介绍了我国目前技术发展的现状,同时指出经济型的蓄热系统设计是CSP系统成功走向市场化的关键技术,双罐熔融盐直接蓄热塔式系统将是我国发展CSP技术努力的方向。     

稠油开采污水蒸发结垢过程传热传质计算方法

蒸发器是一种根据热法脱盐原理,利用稠油热采地面系统废热驱动,实现污水脱盐软化,进而回用锅炉实现水资源循环利用的装置。但是,由于油田污水水质的特殊性,使得其极易在蒸发器表面发生结垢行为。通过对污水水质分析,得出其结垢类型主要为碳酸钙垢。建立了碳酸钙垢在强制对流传热和过冷流动沸腾情况下于换热表面结垢的传热传质模型,计算了污水在蒸发过程中析晶污垢形成的数量,得出了与实验数据符合较好的计算模型。对稠油污水在蒸发器中的结垢情况可以进行较好的预测,并对安全生产和设备高效利用有一定参考价值。     

以最佳型壁温度为目标优化注塑模冷却系统设计

以达到注塑件模具的某一模温为优化目标，考虑了模板热传导阻力和水对冷却水道壁的给热系数，用试差法求解冷却水道一边所需的传热面积，并完成冷却系统的设计计算。     

A Theoretical Model for the Nongray Radiation Drying of Polyvinylalcohol/Water Solutions

A theoretical analysis of heat transfer and moisture variation was performed while a PVA solution was exposed to high-intensity nongray irradiation and/or air flow convection. Effective absorption coefficients were incorporated in the radiative transfer analysis. The influence of various radiation and convection parameters on the transfer of heat and moisture variation in the coated layers on an optically thick substrate was investigated. The effects of radiation and convection parameters on the transfer process were presented in terms of the rate of water content removal, heat transfer, and moisture distribution. Results were compared to those of drying when using convective heat. It is evident that the use of thermal radiation combined with convective heat will help in improving the drying rate. Numerical results show that both the radiative energy absorbed by the solution and the substrate and the distribution of water mass fraction in the solution are closely related to the rate of water removal from the solution during the process.