农业机械发动机冷却系统柔性导风罩的试验研究

对传统发动机冷却系统导风罩进行了改进,对其在发动机室内的布局进行了设计。对柔性导风罩的冷却性能进行了理论分析,并在498柴油机上进行了试验研究。分析了传统导风罩与柔性导风罩的径向间隙对发动机冷却风扇容积效率的影响,散热器进出口处的冷却水温度变化情况等。试验表明：这种柔性导风罩可提高风扇的容积效率,减少风扇的驱动功率,降低燃油消耗。     

柴油机EGR电控冷却系统试验研究

研究了 CA498 柴油机在不同工况下EGR冷却温度对NOx等排放的影响规律,确定了各个工况下EGR的最佳冷却温度,据此设计出一套EGR冷却温度控制装置,可以通过单片机控制伺服电动水泵的转速来调节冷却水的循环量,确保不同工况下的最佳EGR冷却温度.将该电控冷却系统在CA498柴油机上进行了试验.结果表明,与未冷却的EGR系统相比,该EGR电控冷却系统在c0和Hc的排放略有增加的情况下,可以有效地降低NOx的排放、烟度和油耗率.     

基于PWM控制的发动机冷却系统风扇控制方法研究

针对ON/OFF开关控制方法存在的OFF状态冷却效能不足,ON状态冷却效能过剩、能耗高、噪声大的问题,提出了一种基于脉冲宽度调制(PWM)的风扇控制方法,通过对风扇转速的精准控制,有效降低了发动机功耗及噪声,提高了燃油经济性.     

发动机冷却系统匹配仿真研究

应用流体计算软件Flowmaster,建立发动机的热量流动模型。对不同的冷却系统与发动机的匹配方案进行仿真模拟,并对仿真结果进行分析比较,为发动机冷却系统方案的选择与改进提供方向。     

单缸柴油机散热器冷却系统的设计研究

小功率单缸柴油机的水冷却系统有蒸发式和散热器自然循环式,散热器自然循环冷却与蒸发冷却相比,具有结构紧凑,冷却效果好、耗水量少等特点.随着柴油机向轻量化、高强化方向发展,也要求冷却系统在较小的散热面积下获得良好的冷却效果.本文通过对新开发的单缸柴油机冷却系统的设计,研究散热器与风扇之间参数的匹配和相互影响,探讨适合于该形式冷却系统的设计方法.     

发动机电控冷却系统设计及试验

提出取消节温器,水泵、风扇分别电控化的发动机新型电控冷却系统型式,运用集总参数法建立系统的数学模型,并搭建电控冷却系统试验装置;运用反馈线性化方法设计非线性控制器,进行仿真和试验研究;分别设计基本模糊控制器和变论域模糊控制器,进行发动机冷却液温度控制试验。最后综合比较非线性控制、基本模糊控制和变论域模糊控制3种控制策略的控制效果,结果表明:发动机电控冷却系统采用变论域模糊控制效果较优。     

车用发动机冷却系统控制仿真研究综述

介绍车用发动机冷却系统控制仿真的现状及发展,在建立冷却系统各部件数学模型的基础上,讨论分析了智能化冷却系统的控制优化,提出了未来高功率密度发动机冷却系统控制的若干问题.     

发动机冷却系统驱动方式的现状及发展方向

就车用冷却系统对车用发动机的重要性进行了分析 ,并说明了冷却不合理可能对发动机造成的不良后果。对冷却系统驱动方式进行了分类 ,介绍了各自的主要发展过程 ,并分别分析了优点及不足 ,最后展望了冷却系统的未来发展方向及车用发动机冷却系统设计中需要解决的问题     

发动机冷却系统驱动方式的现状及发展方向

就车用冷却系统对车用发动机的重要性进行了分析,并说明了冷却不合理可能对发动机造成的不良后果.对冷却系统驱动方式进行了分类,介绍了各自的主要发展过程,并分别分析了优点及不足,最后展望了冷却系统的未来发展方向及车用发动机冷却系统设计中需要解决的问题.     

风扇在汽车发动机冷却系统中的匹配与优选方法

通过将现有的风扇性能数据编程建库，应用相似理论和计算机程序，控制了风扇在汽车发动机冷却系中的匹配与优选方法，并给出了应用实例。     

空冷汽轮机组控制及保护系统设计特点

阐述了空冷汽轮发电机组的控制及保护系统的设计特点,该系统根据空冷机组的特点,在成熟的纯冷凝汽轮发电机组DEH系统的基础上进行了优化并加入空冷机组背压保护的功能,目前系统已在实际中得到了成功的应用,验证了系统的先进性、可靠性、灵活性的特点。     

高强化柴油机冷却系统电控化设计仿真及试验研究

针对传统冷却系统与柴油机冷却需求不匹配的问题,进行了冷却系统电控化设计仿真研究。基于Simulink软件设计了电控冷却系统仿真模型,提出了电控冷却控制策略,并开展了变柴油机工况条件下电控冷却控制策略验证仿真。对传统冷却部件进行电控化改造（电控海水泵、电控淡水泵和电子节温器）,搭建电控冷却系统试验台架,通过试验分析了电控冷却对柴油机耗油率和热平衡的影响,结果表明：相对于传统冷却系统,电控冷却系统在900 r/min、负荷率30%,1 200 r/min、负荷率60%,1 500 r/min、负荷率90%这3个工况点的耗油率分别降低9.4 g/（kW·h）、6.8 g/（kW·h）和3.9 g/（kW·h）,燃油经济性和热量分配得到改善。     

单元式露点蒸发冷却装置的实验研究

本研究设计了一台由干、湿通道相结合的单元式露点蒸发冷却装置,通过实验研究了蒸发冷却装置在空气经过一级冷却的模式1和经过二级冷却的模式2两种运行模式下,不同空气入口参数时的换热效果。实验结果表明,空气的入口温度越高,换热效果越好;低湿度时空气的进出口温差比高湿度时大,但其湿球效率和露点效率反而较低,这说明2种效率并不适用于不同湿度间的冷却效果对比;模式2运行时的换热效果比模式1好。与已有研究成果对比表明,该单元式露点蒸发冷却装置的湿球效率和露点效率分别可以达到120%和88%,为露点蒸发冷却装置的优化设计提供理论依据和优化方向。     

50装载机用柴油机电子调速系统的应用研究

主要就50装载机用柴油机的使用进行深入研究,针对一拖(洛阳)工程机械有限公司50D-Ⅱ装载机具体的工况使用要求,在现有柴油机上进行改进应用,对直列喷油泵电子调速系统在柴油机上的应用进行深入研究。此应用研究和方案的成功实施,可供类似用途柴油机的应用研究、方案设计提供参考。     

冷辐射地板系统的实验研究

为了研究冷辐射地板系统的热工性能，测试了地板辐射供冷系统的运行工况，得到了地板表面的最低温度、室内的实感温度、热流密度等参数，并初步探讨地板辐射供冷系统结露现象及防治措施，通过实验分析指出这是一种舒适、节能的供冷方式。     

Experimental Study on Thermosyphon for Shipboard High-Power Electronics Cooling System

The closed-loop thermosyphon (CLT) has advantages of simple structure and reliability for transporting heat in long distances with small decrease in temperature. It is considered a promising cooling device for power electronics onboard ships. In this research, CLT for cooling of power electronics onboard ship was developed, and the performance was experimentally examined using a CLT apparatus. The performance was investigated for steady-state heat transfer under a wide range of pressures and heat loads from 18.3 kPa to 35.3 kPa and from 88.9 W to 616.2 W, respectively. The fill charge rates were 27% and 45%. The circulation coolant temperature at the condenser was set to 15°C. The measured data for each rated heat input were registered by a data logger in every 5-s increment of sampling data for a 30-min period. During the steady-state operation, CLT could maintain the system pressure and produced the vapor bulk temperature at around saturation boiling regime. The temperature distributions of the system were measured from each probed thermocouple along the loop. It is understood that higher heat inputs around above 349 W could keep the bulk vapor in an almost constant temperature from evaporation process up to the inlet position of the condenser. The condenser of the direct hull cooling method could also maintain the condensation process with a temperature decrease of around 30°C from the inlet vapor temperature of the condenser. It was clarified that the CLT has good thermal performance in the higher heat loads with low thermal resistance and provides a steady circulation loop from each two-phase process of heating in the evaporator and cooling during condensation.     

Experimental Study on Effectiveness of Celdek Packed Liquid Desiccant Cooling System

Dehumidifier and regenerator are the most important components in a liquid desiccant cooling system. Present paper is focused on study the effect of inlet process parameters on the effectiveness of dehumidifier and regenerator of liquid desiccant cooling system. Experimental study is performed with varying inlet process parameters; mass flow rate of air, desiccant solution flow rate, inlet air temperature, inlet solution temperature, inlet specific humidity and concentration of desiccant solution. Celdek structured pads as packing material and calcium chloride as liquid desiccant is investigated first time using counter flow of the desiccant solution and air. It is concluded from the results that the effectiveness of dehumidifier increases with solution flow rate, inlet specific humidity while decreases with increasing mass flow rate of air, inlet temperature of air and desiccant, temperature and concentration of desiccant solution. The effectiveness of regenerator increases with increasing solution flow rate and inlet desiccant concentration and it decreases with increasing inlet air temperature, air flow rate and inlet solution temperature. Present paper adds to effect of inlet specific humidity, inlet temperature of the air and solution on the effectiveness of desiccant cooling system on the past research.     

基于STM32的变压器闭环控制冷却系统设计

基于对如今市场上变压器冷却系统的调研,设计了一种基于STM32的闭环控制的变压器冷却系统.此系统通过自动采集变压器工作温度信息来自动调节冷却系统的运行参数,保证变压器工作温度恒定;同时将工作参数实时传送回主控室,且在工作现场添加了显示和手动控制功能.实践证明该系统较之前的系统更节能,推广意义重大.     

Cooling System Design

Cooling water systems and refrigeration systems are required to provide cold utility to chemical processes. Little attention has been placed on the structure and system interactions between cooling systems and processes. In this article, an integrated design and retrofit method for cooling systems is reviewed. For cooling water system design, a new design methodology has been developed for debottlenecking of cooling water systems. Reuse of cooling water between different cooling duties enables cooling water networks to be designed with series arrangements. This allows better cooling tower performance and increased cooling tower capacity. The interactions between the performance of the cooling tower and the design of cooling water networks are explored systematically. For refrigeration system design, a systematic design and retrofit method has been proposed for refrigeration systems using pure or mixed refrigerants. A graphical exergy analysis method, the z -H diagram, is introduced to help engineers obtain understanding and insights into complex refrigeration systems. The systematic synthesis method proposed in this article can greatly improve operating efficiency for refrigerant systems.