《节能技术》2002年目录索引

研究与探讨对流干燥过程节能措施的理论分析 (1-3 )……………………燃煤锅炉水蒸气促燃原理及其配送方法 (1-5 )………………合成氨一段炉低温烟道气的有效能计算 (1-8)………………太阳能在建筑节能中应用的探讨 (1-10 )………………………关于静压复得法的理论探讨 (1-14 )     

电站锅炉过热器、再热器分配集箱静压分布计算方法的改进

分配集箱中的静压分布取决于集箱中的流动阻力使静压下降和支管分流使静压上升的综合作用结果。现有的计算方法一般是用一条抛物线简单地描述集箱静压分布，或将支管形式的分配集箱简化成在集箱上开一条均匀宽度的长槽。作者通过理论分析和实验结果，指出这些简化存在的问题，提出了与实际流动情况相一致的离散型数学模型。     

电站锅炉过热器,再热器分配集箱静压分布计算方法的改进

分配集箱中的静压分布取决于集箱中的流动阻力使静压下降和支管分流使静压上升的综合作用结果。现有的计算方法一般是用一条抛物线简单地描述集箱静压分布，将支管形式的分配集箱筒化成在集箱上开一条均匀宽度的长槽。作者通过理论分析和实验结果，指出这些简化存在的问题。提出实际流动情况相一致的离散型数学模型。     

分配集箱静压分布参数Cf值的理论分析

在分配集箱中取微元控制体，通过建立质量守恒方程和动量守恒方程，明确了参数Ｃｆ的物理意义。依据Ｃｆ取值范围，描述了分配集箱静压分布和动量交换控制为主、动量交换与摩擦阻力竞相影响、摩擦阻力控制为主３种情形与Ｃｆ的关系，理论分析与前人试验结果相吻合。同时，对采用我国水动力计算标准方程给出的Ｃｆ＝１．２４计算分配集箱静压分布时，给出了分配集箱长径比的限制。不同的长径比，集箱内静压分布呈现动量交换控制或动量     

锅炉管组集箱静压分布的离散模型

集箱中的静压分布是计算诸如过热器和再热器锅炉管组流量分配的关键。由于集箱中的流动情况十分复杂，在目前的计算方法中，采用连续模型来简化静压分布。一种方法是用一条简单的抛物线静压分布曲线；另一种方法是假定一条连续的长槽来代替集箱上离散的支管。该文通过理论分析和实验结果的比较，指出这些连续模型存在的问题，并通过沿集箱长度有支管和无支管的实际情况列出的动量方程得出离散模型下的静压分布。离散模型的计算结果和     

中凸变椭圆仿形车床的静压尾座设计

本文提出了用静压尾座改造中凸变椭圆仿形车床的观点，阐述了这种静压尾座设计的基本思想，给出了一种静压尾座设计的主要参考数据。     

转子数控车床静压支承系统研究与控制

汽轮机转子数控车床静压支承系统一直存在校调困难的问题,尤其是供油压力及油膜厚度的控制仅凭经验操作,缺乏理论依据。通过对转子数控车床静压轴瓦油膜特性的分析,推导了静压轴瓦油膜厚度及油泵供油压力的理论计算公式,运用有限元仿真软件计算了转子精车加工时所需的静压支承力。计算结果在1 000MW超超临界低压转子加工现场进行了验证,验证结果表明该理论计算方法是准确、有效的。该研究成果将用于指导新产品的现场装夹作业,消除因装夹不当而产生的挠度变形,提高车削加工精度。     

等静压氧化铝瓷及金属化的技术进展和质量评估

对目前国内外氧化铝陶瓷进行了综合介绍，指出在目前高新技术发展的形势下，氧化铝民仍然有着非常广泛的应用，特别是等静压成形的氧化铝陶瓷的需求日益迫发。概述了国内等静压９５％氧化铝陶瓷的性能和标准。着重阐明了等静压机氧化铝瓷金属化技术的困难和解决办法，最后对等静压陶瓷及其封接强度提出了几点质量评估意见。     

静压轴承供油系统的能耗分析

本文从节能观点出发分析了静压轴承的供油系统，指出传统的恒流系统和恒压系统不适于静压轴承间歇承载或外载荷变化范围较大的场合。笔者在实践中采用了压力跟踪供油系统，分析与实践表明：该系统是一种节能型的供油系统，尤其适用于以液压作驱动力的机械设备中的静压轴承。在变载作用下，静压轴承仍具有良好的性能，该系统是一种具有广阔应用前景的新技术。     

基于变风量控制系统运行模式的定静压控制优化

定静压控制是风机变频控制的经典和常用方法。由于静压设定点及静压设定值确定存在一定的难度，给工程应用带来一定难度，导致风机变频调控效果不佳，致使系统运行效率低、能耗高、噪声大。通过介绍基于变风量控制系统运行模式的双运行工况静压值重置法的变频调速技术，助力系统运行效率提升和实验室节能减排。     

300MW汽轮机低压末级叶片的型面压力场

为了改善300MW汽轮机低压末级的流动，哈尔滨汽轮机厂有限责任公司对低压末级静叶进行了改型设计。为验证改型设计成功与否，在环形叶栅低速风洞上对原型和改型两套叶栅沿叶片型面的静压分布进行了实验研究，结果表明改型设计是成功的。     

重型车用柴油机活塞冷却油腔研究

介绍了活塞结构选型及冷却油腔的形状、位置对活塞的冷却效果、机械强度和温度场的影响;及国外一些特殊结构的冷却油腔及重型载重车用柴油机活塞冷却油腔设计所遵循的原则。通过设计实例,对不同形状冷却油腔的影响进行了比较,结论可用以指导设计。     

Development of an axial-type fan with an optimization method

An axial-type fan that operates at a relative total pressure of 671Pa and a static pressure of 560Pa with a flowrate of 416.6m³/min is developed using an optimization technique based on the gradient method. Prior to the optimization of the fan blade, a three-dimensional axial-type fan blade is designed based on the free-vortex method along the radial direction. Twelve design variables are applied to the optimization of the rotor blade, and one design variable is selected for optimizing a stator which is located behind the rotor to support a fan-driving motor. The total and static pressure are applied to the restriction condition with the operating flowrate on the design point, and the efficiency is chosen as the response variable to be maximized. Through these procedures, an initial axial-fan blade designed by the free vortex method is modified to increase the efficiency with a satisfactory operating condition. The optimized fan is tested and compared with the performance obtained with the same class fan to figure out the optimization effect. The test results show that the optimized fan not only satisfies the restriction conditions but also operates at the same efficiency even though the tip clearance of the optimized fan is greater than 30%. The experimental and numerical tests show that this optimization method can improve the efficiency and operating pressures on axial-type fans.     

直接空冷系统管道壳单元分析研究

在直接空冷设计中,主管道的设计占着重要的地位,其首要任务是合理选择结构计算模型,即保证主管道自身的强度和稳定并满足汽轮机排汽装置推力的要求。介绍ANSYS软件在管道设计方面的应用。     

Investigation of the influence of various numbers of impeller blades on internal flow field analysis and the pressure pulsation of an axial pump based on transient flow behavior

In the current study, the flow behavior in an axial pump through changing the number of impeller blades is analyzed. Due to the number of blades being very important geometrical parameters in the pump, the study of the influence of various numbers of blades on flow and pressure pulsation in the pump is carried out using the computational fluid dynamics technique. The sliding mesh with the standard turbulence k‐ε model is used to investigate the unsteady flow with several flows and impeller blades. Pump performance prediction results with available experimental data indicate reasonable and good agreement with each other. Static pressure, shear stress, and different velocity compounds are qualitatively analyzed. Moreover, the fluctuation pressure and average pressure under different operating conditions and impeller blades are quantitatively investigated. The numerical results show that the impeller blade has a high impact on pressure, shear stress, magnitude velocity, axial velocity, radial velocity, tangential velocity, and average pressure. Furthermore, this numerical study provides good and useful information for the hydraulic design of axial pumps.     

某大酒店空调制冷供热系统运行调试中三个问题的探讨

通过对呼市某酒店空调及制冷供热水系统检测调试中发现的三个问题的分析研究,着重探讨了宾馆饭店空调制冷供热系统设计中普遍存在的系统分区、制冷设备选择和空调热水供热系统与低温热水网络连接问题,并提出了相应的改进方案和技术措施。     

太阳能热气流电站透平布置位置研究

基于相对压力概念,建立了太阳能热气流电站系统的新数学模型,并通过数值模拟得到系统内的相对压力分布。根据系统相对压力的分布特点确定了透平布置的最佳位置：在烟囱的底部区域,相对压力最小,压力梯度最大,最适于布置透平;在技术容许的情况下,为实现能量转换效率最高,不宜采用能量梯级利用方案。     

Determination of energy loss characteristics of dampers

The pressure loss coefficient of a flat‐plate damper for ducted air systems has been determined using computational fluid dynamics (CFD) and experimental measurement. The constant‐injection tracer‐gas technique and a pitot tube were used to measure mean air velocity in a square duct fitted with a damper. Pressure distribution along the duct was measured using static pressure tappings. The pressure loss coefficient was calculated from the measured pressure loss and mean velocity for the duct fitting. CFD was used to predict airflow and pressure distribution in the duct. The predicted pressure loss coefficient was generally in good agreement with experimental results. The pressure loss coefficient for the damper was found to be sensitive to the clearance between the fitting and duct as well as the degree of damper opening. Copyright © 1999 John Wiley & Sons, Ltd.     

EXPERIMENTAL STUDIES ON FLOW IN CONVERGENT AND DIVERGENT DUCTS OF RECTANGULAR CROSS SECTION

This paper describes the experimental examination of the pressure drop and heat transfer of the flow in convergent and divergent ducts of rectangular cross section. The aspect ratio based on the dimensions of the large end of the duct was 0⋅1. It has been found that at a given convergent or divergent angle pressure drop decreases while heat transfer increases with increasing Reynolds number. Along a given duct of small convergent angle, pressure drop increases while heat transfer decreases along the duct. However, heat transfer may increase near the downstream end of ducts of high convergent angle. At a given Reynolds number, both pressure drop and heat transfer increase with increasing convergent angle. As for flow in divergent ducts, the effects of Reynolds number on pressure drop and heat transfer are somewhat similar to those of flow in a convergent duct. © 1997 by John Wiley & Sons, Ltd.     

Thermo‐Economic Analysis and Multiobjective Optimization of Dual Pressure Combined Cycle Power Plant with Supplementary Firing

The heat recovery steam generator (HRSG) and duct burner are parts of a combined cycle which have considerable effect on the steam generation. The effect of the gas turbine, duct burner and HRSG on power generation is investigated to reduce exergy destruction and power loss in the gas turbine. The results show that with an increase in duct burner flow rate, pressure loss in the recovery boiler increases, steam generation increases on the HP side while it decreases on the LP side. With a reduction in the HP pinch point, thermal recovery increases while the LP pinch point does not have a significant effect. Then, power loss due to pressure drop in the gas turbine and the electricity cost are considered as two objective functions for optimization. Finally, the sensitivity analysis on ambient temperature, compressor pressure ratio, fuel lower heating value, duct burner fuel rate, condenser pressure and main pressure are performed and results are reported. It is concluded that with an increment in compressor pressure ratio, the duct burner flow rate and consequently steam generation increases while electricity cost decrease.