1m铣刨机散热系统的匹配讨论

本文通过选型计算,对1米铣刨机的散热系统进行了匹配。完成了冷却风扇、散热器等冷却系统主要部件的匹配选型,并通过样机测试来校核原始的设计数据。其中涉及到风扇直径、转速、风量,以及整机散热功率、散热器散热面积、冷却效率等参数的计算方法。通过实例匹配计算,介绍了一种即科学又简便的匹配选择方法。     

振动压路机冷却系统方案试验研究

振动压路机中发动机故障的30%由冷却系故障引起的,特别是在环境比较恶劣如新疆等高原地区,必须要有良好的冷却系统才能保证压路机的可靠作业。为提高压路机对恶劣环境的适应能力,我们对压路机的冷却系统进行热平衡试验,通过风扇和冷却系统中水散热器、中冷器、液压油散热器布置形式的改变,并选用三台压路机进行热平衡对比试验,确定了中冷器、水散热器、液压油散热器并联布置加吸风风扇的冷却方案,取得了理想的散热效果。     

降低某型内燃叉车散热系统风扇噪声的试验研究

某型内燃叉车的散热系统风扇噪声是其首要噪声源,针对该问题,通过对叉车散热系统的匹配设计进行分析,发现散热系统风阻偏大和风扇选型不合理是导致风扇噪声的主要原因,为此,从风扇选型、散热器组设计、导风罩设计及风道设计等方面提出改进措施,并进行试验验证,最终成功解决了风扇噪声问题。     

大型液压挖掘机冷却系统分析与设计计算

通过对液压挖掘机冷却系统分析,介绍了大型挖掘机的散热器、冷却风扇设计计算,给出了计算公式,可方便设计人员了解掌握大型液压挖掘机冷却系统配置。     

工程机械水冷系统的优化设计

本文以柴油机水冷系统为目标,通过冷却系统散热能力的分析和计算,对散热器的优化设计和选型进行探讨。     

矿用自卸车冷却系统的仿真与试验研究

以矿用自卸车的冷却系统为研究对象,采用试验和仿真相结合的方法分析了防热风回流装置对冷却系统散热性能的影响。通过矿用自卸车热平衡试验,实测最大扭矩与额定功率工况的冷却系统散热性能评价数据,并进行有风挡与无风挡状态的比较;基于冷却系统仿真模型,输入计算所需的水泵、散热器、风量等边界条件,对冷却系统进行一维流体仿真分析。通过试验和仿真结果的对比分析可知:仿真结果和试验数据基本一致,表明此仿真模型可靠,在设计初期可以为冷却系统的设计选型提供理论依据,提高冷却系统分析效率,节省试验费用;防热风回流装置可以有效提高冷却系统的散热性能,降低研发成本。     

一种6t级悔能型装载机的冷却系统

介绍天津工程机械研究院自主研发6t级节能装载机的独立散热冷却系统,该系统由风扇、定量泵、定量马达、电比例溢流阀、温度传感器、温控阀和控制器等部件组成,通过一个独立可控的液压系统驱动冷却风扇,采取模糊控制方式,对发动机冷却液、液压油、变矩器油3种介质同时进行散热。该冷却系统具有结构简单,控制准确,操作方便,安全可靠,冷却介质温升快,性能稳定等特点。     

YZ16H压路机水温过高的原因及解决方法

我公司自行设计的ＹＺ１６Ｈ振动压路机配置的发动机是东风康明斯６ＢＴ５．９水冷发动机,其转速为 ２ ５００ ｒ／ｍｉｎ,功率 １１３ ｋｗ;散热器散热总面积３４ ｍ２,正面散热面积为 ０．６６×０．６ ｍ２（散热器芯部宽度×高度）;吸风式风扇外径为 φ５８０ ｍｍ。样机经测试后发现,发动机水温过高,甚至开锅。 影响发动机冷却系统散热效果的主要因素有冷却系统的布置、进风系数、散热器的选择、护风罩的形式和风扇的尺寸等。１ＹＺ１６Ｈ压路机冷却系统的布置 冷却系统的布置由空气流通系统和冷却液循环系统两部分组成。图１是…     

装载机液压驱动风扇匹配计算

液压驱动风扇的散热系统需要匹配计算和选型才能更大程度地发挥其性能优势和节能效果,针对装载机液压驱动风扇散热系统的匹配计算及元件选型等方面进行探讨。     

液压驱动扇控制器的研制

液压驱动风扇冷却系统由多个散热器、温度传感器、控制器、液压泵、液压马达、调节装置、油箱、过滤器等组成,控制器不断检测温度传感器的温度信号和其它输入信号,经过处理和运算后输出至调节装置,使冷却系统能够根据冷却介质温度的高低,自动调节风扇转速,提高散热能力。开发一种基于XC164微控制器的液压驱动风扇控制器,由微控制器、电源电路、信号处理电路、驱动及保护电路、通信及接口电路等组成。介绍系统的基本原理、控制器硬件结构和控制算法,对控制器进行功能测试,并应用于轮式装载机上进行试验。结果表明：该控制器能根据冷却介质的温度变化使风扇转速产生连续变化,使各种冷却介质的温度维持在最佳范围内。     

冷却塔风机运行节能之模式与策略的分析

冷却塔风机是整个冷却水系统的核心设备,其运行状况直接关系到系统性能与能耗状况.本文针对国内某办公建筑的冷却塔风机运行状况进行实测,从风机与变频器电耗、冷却塔效率、冷机COP,设备寿命与运行策略的可行性4个方面分析评价了风机运行模式和策略对能耗的影响.     

Evaluation of cooling effects: outdoor water mist fan

Evaporative spray cooling systems can be used to provide thermal relief on hot days, even in a subtropical climate such as in Japan. An experiment combining a water mist spray with a fan was conducted to cool an outdoor space and ascertain the comfort of 141 participants on hot summer days. Each participant was surveyed for ‘thermal sensation', ‘general comfort' and ‘feeling of wettedness' and skin temperature was measured before and after entering a mist. To characterize more directly the cooling effect of this particular mist system, a dry silicone rubber skin analogue including embedded heat flux sensors was heated to near-body temperature to measure the near-surface heat flux due to natural convection, forced convection by the fan alone, and the fan and mist together. It was found that the cooling effect of the mist and fan combination is highly efficient and easily exceeds the thermal load of pedestrians, yielding nearly instant decreases in skin temperature. Such outdoor technology has potential to reduce heat stress and discomfort, particularly at large outdoor events and festivals. It could also reduce the required cooling loads within individual buildings by providing inhabitants with thermal relief outdoors.     

顶板辐射供冷加置换通风系统广州地区适用性分析

顶板辐射供冷加置换通风系统以其独有的舒适性好、能耗低等特点逐步被国内用户接受,并在民用建筑项目中被采用.本文以等效辐射换热系数方法对盘管式辐射顶板单位面积的供冷量进行了数值模拟分析,并以广州地区为例,对该系统的适用性及影响因素进行了讨论:顶板辐射供冷加置换通风系统更适用于围护结构冷负荷指标低的节能建筑;当围护结构冷负荷指标低于20 W/m2时,采用较高供回水温度的冷水机组可满足室内设计要求且有明显的节能效果;顶板承担的冷负荷随人员密度的增大而减小,降低送风温度、采取大温差送风,可降低顶板承担的冷负荷.     

XT680-170型伸缩臂叉装机热平衡试验分析

通过整车热平衡试验,对伸缩臂叉装机高速跑车和叉装举升两种工况进行热性能测试,考察整机的热平衡性能;通过试验数据分析对整机散热匹配性能进行评价,为叉装机散热系统的优化设计提供试验数据和改进建议.     

Improving photovoltaic panel performance via an autonomous air cooling system – experimental and numerical simulations

ABSTRACT

The temperature rise of a PV panel during its functioning is known to induce losses of its performances. We propose to minimise these losses via a simple and autonomous air cooling system composed by a fan activated by the electricity produced by the panel. This fan blows ambient air on the rear face of the panel. Experimental measurements of the current intensity as well as voltage delivered by the panel and its front face temperature ensure the validation of the numerical code. Numerical and experimental results are in good agreement. As the main results of this autonomous cooling, when compared to the uncooled panel situation, the efficiency for harsh climatic condition increases of 29.52% while the panel temperature lowered of 39.29°C. Such results achieved with this quite simple autonomous cooling system on the improvement of the PV panel efficiency suggest interesting economic and commercial arguments.     

10000t／d回转窑风机冷却系统的数值模拟

本文首先介绍了新型干法水泥生产回转窑两种常用冷却方式,然后针对中国建材装备总公司承建的国外某10000t／d生产线的回转窑工作环境条件。确定了鼓风冷却方式。其次,采用生产实践和CFD（Computational Fluid Dynamics）数值模拟技术相结合的方法,实现了对该回转窑鼓风冷却效果的研究,最后得出该回转窑可以在50℃环境温度下安全工作的结论。     

Energy consumption criteria and labeling program of wet cooling towers in Iran

Increasing concerns about the lack of energy resources, global warming and environmental pollution have pushed the relevant organizations to develop energy saving strategies such as energy labeling programs. In this research, a new energy labeling program is developed and evaluated for the wet cooling towers in Iran. The cooling tower parameters, including its cooling capacity and the fan power consumption, are measured using an experimental setup. The experimental data are standardized to compensate the effect of the ambient wet bulb temperature on the cooling tower performance which cannot be controlled during the experiments. The results show that the cooling tower capacity and the fan power consumption may be correlated properly using a linear function which conducts the authors to present a linear energy index (EI). Based on the statistical analysis of a comprehensive range of products, the energy rating limits are extracted for the main types of cooling towers, including induced draft and forced draft ones. The economical and environmental impression of the program authorization is also discussed in detail. Administration of such program may lead to considerable energy saving in the cooling systems which have major economical and environmental benefits, especially in the large industries.     

Energy saving and improved comfort by increased air movement

In this study, the potential saving of cooling energy by elevated air speed which can offset the impact of increased room air temperature on occupants’ comfort, as recommended in the present standards (ASHRAE 55 2004, ISO 7730 2005 and EN 15251 2007), was quantified by means of simulations with EnergyPlus software. Fifty-four cases covering six cities (Helsinki, Berlin, Bordeaux, Rome, Jerusalem and Athens), three indoor environment categories I, II and III (according to standard EN 15251 2007) and three air velocities (<0.2, 0.5 and 0.8 m/s) were simulated. The required cooling/heating energy was calculated assuming a perfectly efficient HVAC system. A cooling energy saving between 17 and 48% and a reduction of the maximum cooling power in the range 10–28% has been obtained. The results reveal that the required power input of the fan is a critical factor for achieving energy saving at elevated room temperature. Under the assumptions of this study, the energy saving may not be achieved with the methods for air speed increase, such as ceiling, standing, tower and desk fans widely used today when the power consumption of the fan is higher than 20 W.     

一种集中空调冷量计费方法

以风机盘管空调系统为例,介绍了集中空调系统的控制特点、计费依据和计费原理,在冷量计量的基础上给出了一种可行的计费方法。     

住宅用地板辐射供冷系统的实验分析

针对夏热冬冷地区的气候特征,分别从室内温度场、湿度场、风速场以及地板换热等出发,比较了住宅用冷却地板单独供冷、风机盘管单独供冷及两者联合运行三种供冷方式。结果显示,冷却地板与风机盘管联合运行可以满足夏季供冷要求,而且克服了冷却地板易结露的缺陷,具有良好的舒适性和节能性。