北方地区建筑渗风能耗与传热能耗的比例分析

高层建筑渗风能耗已成为暖通专业中不容忽视的问题，本文不北方地区高层住宅建筑的渗风能耗以算例的形式进行了具体的量化分析，提出了减少渗风能耗的几种方法。     

小雨条件下入渗土壤中水—气运移规律试验

探明非饱和土壤水分入渗中水—气运移的规律及相互关系,有利于促进水分入渗规律和溶质运移规律的深化研究。基于室内土柱试验,研究了在小雨量(15mm/d)连续降雨入渗条件和土中气相影响条件下水分入渗的变化规律。结果表明,土中水分入渗能力随时间和深度递减;气压势与含水率呈负相关,与基质吸力呈正相关;多项式和对数函数对土—水特征曲线的拟合较为理想;入渗系数随剖面深度加大而减少。试验结果较好地解释了试验过程中出现的积水现象,对深入研究非饱和土壤水分入渗规律意义重大。     

Modelling of a new hydro-compressed air-storage system

The interest in energy storage systems is increasing, since it provides an excellent solution to store the low-cost excess energy from the energy sources, which are available at peak demand hours. This paper presents a new compressed-air storage system that combines ambient air and hydraulic oil, in order to store energy in compressed-air form and benefit from the advantages of both pneumatic and hydraulic systems. The process consists of charging and discharging cycles, however, this paper investigates the discharging cycle, where a new technique of Small-Scale Compressed Air Energy Storage (SS-CAES) system is realised. The new idea in RC-CAHES is to obtain higher efficiency in energy conversion machines during charging and discharging processes with numerous advantages over conventional types of energy storage systems. This study demonstrates the effectiveness of this technique by proving that it has higher efficiency than a similar Compressed Air Energy Storage (CAES) systems.     

锅炉烟气酸露点温度计算及对预热器腐蚀的影响

锅炉烟气流经空气预热器时,当空气预热器金属壁温低于烟气酸露点温度时,即生成硫酸,从而导致空气预热器冷端腐蚀及堵灰。本文介绍了锅炉烟气酸露点温度的计算及对预热器冷端腐蚀的影响。     

基于模型的发动机空燃比控制策略研究与仿真

空燃比的精确控制是现代车用汽油机控制最为关键的技术。发动机平均值模型由于其模型简单、计算时间短、使用方便,且能满足控制设计的要求而被广泛应用。基于模型的空燃比控制技术是当前国内外研究的热点。在建立某型汽油发动机空燃比平均值数学模型的基础上设计了稳态工况下模糊自适应PID控制器,并与传统的PID控制器空燃比控制效果进行了对比。设计了瞬态工况下燃油前馈补偿控制器并进行仿真。仿真结果表明在稳态工况下模糊自适应PID控制策略不仅能够满足实际控制需要,而且比传统的PID控制策略控制效果更好。前馈补偿控制策略能满足瞬态工况下空燃比的控制要求。     

空气隙膜蒸馏系统对流换热实验研究

空气隙膜蒸馏是一种新型的膜分离技术,可用于海水、苦咸水的淡化处理,尤其是在超纯水制备方面具有极强的竞争力.文中的空气隙膜蒸馏实验装置采用旋转切向入流的方式来强化膜蒸馏的传热传质过程,针对这种新型的入流方式,结合实验数据,给出了料液进口温度对于膜通量的影响,给出了计算空气隙膜蒸馏系统中热容腔内对流换热传热系数的经验公式.     

流动风阻网格模型与热仿真设计方法优化动力电池模组结构的研究

风冷系统因结构简单、成本低等特点,在热管理系统中占据重要地位。目前常规的风冷热管理设计方法存在重复性工作多、设计时间长的缺点。本文提出空气流动风阻网格模型结合热力学模型仿真的设计方法,先采用空气流动风阻网格模型获得优化的电池结构,再采用热力学模型进行仿真求解,获得优化的电池模组的流场和温度场分布特性。仿真结果验证了优化结构的准确性。优化结果表明,“C”字形结构更有利于提升模组内单体电池冷却效果的一致性,并且优化后的“C”字形结构进一步提升了电池模组内单体电池温度场的一致性。此外,计算结果发现模组内空气流动方向为上进下出时可进一步降低模组内单体电池的最高温度,提升单体电池温度场的一致性。     

Comparison between Measured and Model ( LBLand BRE) Predicted Infiltration Rates for a Passive Solar Test Cell

The pressurization technique is applied to the test cell at the JRC, Ispra, and important parameters for the LBL and BRE air infiltration models are calculated. The predictions of these models are compared with the tracer gas (SF₆) measurements. The differences between measured and predicted values of the air infiltration rates axe quite large. When the model parameters calculated from the tracer gas measurements are used, both models predict infiltration rates in good agreement with the field measurements. This means the physical models are acceptable but there is a need to refine the procedure for determination of model parameters.     

征收碳税对我国二氧化碳减排的影响

我国的大气污染问题亟需大力整治,调整以煤为主的能源结构是根本途径,体现环境成本与征收碳税是重要方法之一,且在国外已有成功经验.本文利用联立方程模型,通过假设不同碳税征收的情景,分析碳税对我国原油、天然气及煤炭消费的影响,继而测算对二氧化碳减排的影响.结果表明,征收碳税可对碳减排起到显著的作用,可促使能源结构向清洁化发展,化石能源消费受到抑制,但受影响程度不同,煤炭消费受影响最大,天然气消费受影响最小.在碳税征收上应采取循序渐进的征收方式,避免对经济和行业发展产生较大冲击.     

高温空气燃烧技术的特点及其应用前景

高温空气燃烧技术（HTAC）是九十年代初在日本开发的一项新的燃烧技术,该项技术具有节约燃烧、低NOx排放、热利用率高和减设备尺寸等特点。分析了HTAC的火焰温度分布特征及其可降低NOx排放的原理。高炉煤气、焦炉煤气及94．5％高炉煤气与5．5％焦炉煤气的混合煤气应用于HTAC技术的理论计算结果表明,理论燃烧温度随着预热空气和燃气温度的升高而升高,因此HTAC技术可燃用传统燃烧方式不能使用的低热值燃气。此外,空气、燃气双预热可奖排烟温度将得更低,热利用率提高更高。最后,指出了在燃油、燃气锅炉及煤（或可燃固体废弃物）气化系统中采用HTAC技术的可能性。     

Can environmental investment and expenditure enhance financial performance of US electric utility firms under the clean air act amendment of 1990?

This study investigates the causality from environmental investment (as a long-term effort) and expenditure (as a short-term effort) to financial performance in the US electric utility industry. The industry is one of the large air polluters in the United States. This empirical study finds that the environmental expenditure under the US Clean Air Act has had a negative impact from 1989 to 2001. The negative impact has become much effective after the implementation of the Title IV Program (1995) of the US Clean Air Act. This study cannot find the influence of environmental investment on financial performance by a statistical test although it indicates a positive impact. In the United States, fossil-fueled power plants such as coal-fired ones still produce a large portion of electricity. The generation structure is inconsistent with the betterment in the US environmental protection and imposes a financial burden to electric utility firms.     

Analysis of single side ventilated and cross ventilated rooms by varying the width of the window opening using CFD

Natural ventilation contributes to the improvement of thermal comfort and quality conditions of the internal air and at the same time it is recognized very effective technique when applied properly. The present project refers to the numerical predictions of air velocities in cross and single-sided naturally ventilated rooms which are considered along with atmospheric zone. This is done for different sizes of the opening at particular height of the wall. Continuity and Momentum equations have been solved by control volume method. SIMPLE and SIMPLEC algorithm are used to solve these equations. Steady, k-ε turbulence model and incompressible flow of a constant property fluid under Boussinesq’s approximation have been considered. Air velocities were taken at various heights from middle of the opening and compared for single side ventilated and cross ventilated rooms. Air flow rate increases with increase of width of the opening.     

摩托车液压前叉减震器气柱力的计算研究

通过对摩托车液压前叉减震器的结构和工作原理的分析,建立了前叉管上部密闭空间气体热力学的模型,详细介绍了基于综合反力的气柱力计算方法,给出了减震器结构参数、空气柱体积、气柱力与注油量之间的关系,并与实验测得的曲线进行了对比。结果表明:摩托车液压前叉减震器气柱力与空气柱体积之间的关系基本遵循理想气体多变过程的变化规律,且多变指数n=1~1.05,在实际计算中可以将气柱力的变化过程看作等温过程(即n=1)。     

Radiative heat transfer in preforms for microstructured optical fibres

Air inclusions in any preform for microstructured optical fibres can greatly reduce conductive heat transfer. Modelling the heat transfer therefore requires that radiation be properly included. In this paper we use the Rosseland approximation to consider radiative heat transfer within the matrix material and present a method of including radiative heat transfer across the air inclusions for the first time. We apply the thermal model to the transient heating process of a silica preform with a hole structure that restricts conduction. The resultant heat transfer model yields realistic heating times.     

Simulation of the performance of single jet air curtains for vertical refrigerated display cabinets

Air curtains are widely used in refrigerated display cabinets as well as doorways of cold rooms and retail premises. The main purpose of the air curtain is to reduce the air exchange and hence heat and moisture transfer between the conditioned environment and the surrounding ambient. This paper presents a comprehensive model, based on the finite difference technique, which can be used to predict and optimise the performance of air curtains. Based on results obtained from the model, correlations for the heat transfer across refrigerated display cabinet air curtains have been developed to enable quick calculations and parametric analyses for design and refrigeration equipment sizing purposes. Both models have been validated against results from tests on a vertical refrigerated display cabinet air curtain.     

不同方法制备的TBC涂层特性的研究

众所周知,热障涂层（TBC）主要包括粘接层和面层两部分。该文采用空气助燃超音速火焰喷涂（HVAF）和氧气助燃超音速火焰喷涂（HVOF）两种方法制备粘接层,大气等离子喷涂（APS）方法制备面层,来研究不同制备方法对TBC涂层微观结构和性能的影响。试验结果表明,HVAF和APS制备的TBC涂层,粘接层中氧化现象较少,热生长氧化物（TGO）生长相对致密均匀,以α-Al2O3为主,其它复合氧化物（NiO、CrNi、CoNi等）较少,表现出较好的高温性能。YSZ陶瓷面层隔热效果良好,是一种成本低廉的新型制备TBC涂层技术。     

天然气发动机混合器结构设计研究

混合器结构对保证天然气与空气的混合以及两者的流量满足合适的比例有着重要影响.通过理论计算分析,得出满足天然气发动机正常工作的混合器喉口直径与燃气孔直径的关系.根据发动机过量空气系数与平均有效压力关系,针对某发动机进行了混合器管路的结构设计.结合整机实验进行空燃比测试,验证了混合器设计的合理性.     

FWEC管式空气预热器管子管板胀接工艺

根据FWEC管式空气预热器技术规范对管子—管板胀接的要求,对有缝电阻焊管胀接进行工艺试验。通过试验结果及分析,确定了合理的胀接工艺及参数,满足了技术规范对壁厚减薄的要求并应用于产品制造。同时介绍了产品胀接实际应用情况及经验,并对管板的胀接结构提出改进建议。     

高温空气燃烧技术中燃烧特性的研究进展

高温空气燃烧(HTAC)技术是集节能与环保的新型燃烧技术,被燃烧界誉为21世纪最有发展前景的燃烧技术之一.讨论了HTAC系统常见的基本类型和燃烧机理,介绍了HTAC的工作原理与主要特点,从火焰特性、温度特性、污染物(NOx)排放特性等3个方面,对HTAC燃烧特性的研究现状和进展进行了系统的阐述,并探讨了需要进一步研究的内容.     

FLⅡ-16型文丘里送风量测量装置的改进分析

华能平凉电厂一期4×300MW机组锅炉送风量测量装置原采用机翼式风量测量装置,该测量装置取样管经常被灰尘堵塞,使得送风量无法被准确测量,经常出现偏大、偏小或突然波动的现象,导致送风自动经常解列,严重影响锅炉MFT保护的可靠性和锅炉运行的经济性。为此,对送风量测量装置进行技术改造,采用双(多)翼型文丘里组合结构的测量装置,提高了测量精度,机组保护装置的安全可靠性和锅炉运行的经济性。