椭圆翅片管热浸锌质量要求与控制

椭圆翅片管是直接空冷器管束上的冷却元件,因为直接空冷器使用环境的特殊性,所以对空冷器表面要进行良好的防腐处理。我厂对椭圆翅片管表面防腐采用热浸锌,以提高空冷器的使用寿命。椭圆翅片管热浸锌的质量要求,不仅包含热浸锌部件浸锌质量的一般要求,同时还包含椭圆翅片管作为冷却元件浸锌质量的特殊要求。将针对椭圆翅片管的热浸锌质量要求进行分析,并阐述如何进行椭圆翅片管的热浸锌质量控制。     

用空冷器代替冷却塔的技术经济性分析

本文就电厂中用空冷器代替冷却塔的可行性进行了分析。以给定工况下的电厂为例 ,分别计算了采用冷却塔和空冷器两种系统下的设备费用和运行费用 ,分析了变工况下空冷器的经济性能。通过分析看出 ,若当地气温在 5℃左右 ,风速维持在 2 4m/s时 ,空冷器可以省去风机 ,而且能耗和费用将降低 ,经济性能将优于冷却塔方式。对于一个 1 5 0 0kW的发电机组 ,每年可节约循环水 7 395万t。空冷器同样适用于石化等行业的冷却水循环系统。因此 ,在气候条件适合的北方地区 ,采用空冷器是节水的有效途径。     

高温季节电炉循环水冷却方式的改进

大功率电炉变压器在夏季高温期间，因循环水冷却速度慢，水温降不下来，油水冷却器降温效果不好，而经常超温报警，造成电炉不能正常冶炼，直接影响生产的正常进行。对循环水冷却方式进行改进后，解决了上述问题，保证了电炉的正常运行。     

大功率风力发电机冷却系统的试验研究及数值模拟

冷却系统是风力发电系统的重要组成部分,其性能的优劣是衡量发电机能否安全可靠运行的重要因素。文章针对某型3 MW风力发电机的冷却问题,搭建了风力发电机试验台,研究了100%负载条件下冷却系统的性能表现,并采用数值模拟方法对其进行分析,提出了4种优化方案:1增大乙二醇流量;2降低乙二醇进口温度;3增大空气流量;4采用空心导线冷却方式。试验和模拟结果表明:电机在100%负载条件下温度高于电机所要求的工作范围,需要对冷却系统进行优化;空心导线冷却方式能对电机高温区域进行集中冷却,使温升符合电机工作要求,是冷却系统的最佳优化方案。文章的研究方法和研究结果可为我国风力发电机冷却系统的相关研究提供试验和理论参考。     

分压式供水在冷却循环水系统节能改造中的应用

介绍冷却循环水系统采用分压式供水的原理和应用案例,这是循环水系统节能改造的一种新方法。案例表明,通过对循环水系统不同高度的换热装置进行分压供水,可以达到可观的节能效果。     

发电机空冷器传热与阻力特性研究

随着空冷汽轮发电机容量的增大,发电机内各部件的发热量也随之增加,空冷技术的重要性日益突出。但我国的空冷技术与国外相比还有一定差距,因此,利用循环风洞对几个特定结构参数的翅片式空冷器进行了模化试验研究,获得了空气侧传热与阻力特性的准则关系式,就试件结构参数对传热及阻力特性的影响机理做了详细的分析。试验结果不但为国产空冷器的性能与结构优化提供了计算方法,而且为空冷器制造企业实现自主研发提供了可靠的依据。     

循环冷却水水池补水方案

在企业用水设备中 ,一般冷却用水量较多的设备 ,比如 :热处理设备、空压机等常采用循环水间接冷却的方式。工作中发现 ,在使用循环水冷却的过程中 ,有一部分冷却水在循环的过程中流失 ,流失途径大致有 :水池渗漏循环水池年久失修 ,开裂造成漏水。水池溢水水池溢水的原因有多种 ,例如 :1 补充水失控冷却水在循环的过程中有一部分自然损耗 (如冷却塔风机风力带走一部分水量 ) ,需适时补充自来水。补水方式有手动补水和自动补水两种方式。　　手动补水是采用人工打开进水阀门 ,水池水面升高到原工作时正常水位 ,再关闭进水阀门。但有时不能及时…     

水轮机在循环冷却水系统的节能改造应用

在循环冷却水装置运行过程中,传统模式一般采用减速器加传动轴的电机驱动风机对循环水回水进行冷却,随着新技术的不断开发,水轮机技术应用到循环水系统中,可充分利用循环水系统富余回水位差势能,采用混流式可调速水轮机代替传统的电动机带动风机转动,取代了电机等设备,不需电量消耗,适用水头范围广、结构简单、运行可靠,在保证冷却效果、确保平稳生产的同时,达到了良好的节能效果。     

安徽安庆电厂发电机与励磁机冷却用水节能改造方案探讨

安庆电厂一期工程2台320MW机组,设计时发电机氢冷器与励磁机空冷器用开式水冷却,经过4年多的运行发现开式水存在弊端。将发电机氢冷器与励磁机空冷器由开式水冷却改为闭式水冷却后,一方面可以提高安全性,另一方面可利用闭式水的废热在冬季提供给集控采暖用与加热补给水等,并就闭式水系统的两种方案进行了技术经济性比较。     

快速喷雾结冰技术在循环冷却水塔中的应用

针对我国北方地区发电厂中冷却水塔冬季防冻问题,提出了循环冷却水塔快速喷雾结冰技术．通过与悬挂挡风板冷却塔的对比,论证了快速啧雾结冰技术在优化调节循环水温度及循环冷却水塔防寒防冻方面的明显优势．结果表明：采用快速喷雾结冰技术能够使冷却水塔在严寒季节或天气情况突变时安全运行,可以使机组循环水温度随着环境温度高低和机组负荷大小而自动调整,以达到最佳值,从而提高了机组的经济性．     

超声波管道防垢器在空气压缩机级间冷却器中的应用

介绍了TA6000离心式空气压缩机的工况。经分析,该空气压缩机出现二、三级气体入口温度升高而导致联锁停车的原因是循环冷却水水质较硬,致使冷却管壁结垢,降低了级间冷却器的冷却效果。针对这种情况,在压缩机循环冷却水入口处安装TC-2-20型高温高声强超声波管道防垢器,进行在线防垢除垢,达到了较好的防垢除垢效果,安装前,压缩机级间冷却器1a清洗2～3次,安装后h只需清洗1次;同时还起到了一定的强化换热作用,安装后,压缩机二、三级气体入口温度平均下降了2～3℃。     

Thermodynamic performance analysis of gas-fired air-cooled adiabatic absorption refrigeration systems

In China, the application of small size gas-fired air-cooled absorption refrigeration systems as an alternative for electric compression air conditioning systems has shown broad prospects due to occurrence of electricity peak demand in Chinese big cities and lack of water resources. However, for conventional air-cooled absorption refrigeration systems, it is difficult to enhance the heat and mass transfer process in the falling film absorber, and may cause problems, for example, remarkable increase of pressure, temperature and concentration in the generators, risk of crystallization, acceleration of corrosion, degradation of performance, and so on. This paper presents a gas-fired air-cooled adiabatic absorption refrigeration system using lithium bromide–water solutions as its working fluid, which is designed with a cooling capacity of 16 kW under standard conditions. The system has two new features of waste heat recovery of condensed water from generator and an adiabatic absorber with an air cooler. Performance simulation and characteristic analysis are crucial for the optimal control and reliability of operation in extremely hot climates. A methodology is presented to simulate thermodynamic performance of the system. The influences of outdoor air temperature on operation performances of the system are investigated.     

高效喷雾通风冷却塔在循环水场中的节能分析

高效喷雾通风冷却塔通过通风蒸发、热传导形式带走热量来完成热水的降温过程,其主要特点是喷流雾化和利用循环水的余能来推动空气在冷却塔内的强制流动,从而代替轴流风机达到节电节能的目的。其核心部件是喷雾推进雾化器,其主轴采用高分子非金属耐磨材料制造,克服了用油轴承在水环境中易锈蚀、卡死等故障,减少了设备维修量。2008,中国石化洛阳分公司采用高效喷雾通风塔冷却技术对第三循环水场3号塔进行了改造,投用至今运行稳定,主要运行参数达到了预期的目的,冷却效果与使用轴流风机相当,循环泵电流与改造前相当,没有增加循环水的回水管路阻力。若洛阳石化循环水冷却塔轴流风机全部进行此技术改造,保守计算年可节电1500×10^4kW·h。     

Numerical investigation on the heat and mass transfer in a direct evaporative cooler

A simplified mathematical model is developed to describe the heat and moisture transfer between water and air in a direct evaporative cooler. The mass of evaporated water is treated as a mass source of air flow, and the related latent heat of water evaporation is taken as a heat source in the energy equation. The momentum caused by water evaporation is taken into account in the momentum equations. The effective air viscosity and diffusion coefficient are decided experimentally. The models and methods are validated by comparing the numerical results with those of experiment for the same evaporative cooler. The influences of the inlet frontal air velocity, pad thickness, inlet air dry-bulb and wet-bulb temperatures on the cooling efficiency of the evaporative cooler are calculated and analyzed.The cooling effects of the direct evaporative cooler are predicted for use in four different regions in northwest China using the present numerical method and local weather data for air conditioning design. The predicted results show the direct evaporative cooler with high performance pad material may be well applied for air conditioning with reasonable choices for the inlet frontal velocity and pad thickness.     

水轮机节能技术在石化行业循环水冷却塔中的应用

水轮机利用循环水泵的富余扬程带动风机运转,以取代风机电机,实现节能的目的。以高效反击混流式水轮机在青岛石化循环水冷却塔中的应用为例,通过监测单开水轮机风机或电动风机时循环水的温降程度,来对比两种风机的运行效果,并在维持系统管网压力、流量不变的条件下,监测水轮机风机正常运行、转速减半、停运至系统稳定,以及重开风机系统、恢复稳定状态下的运行数据,测试水轮机风机运行对循环水系统的影响,从而验证水轮机节能技术的应用效果及经济效益。结果证明,循环水系统存在富余能量,水轮机利用该富裕能量带动风机运转,不增加循环水系统新的能耗;且水轮机风机降温效果与电动风机相当,可替代电机风机运行,满足精细化操作需要。采用水轮机运转风机,可优化循环水系统配置,减少维护保养费用,经济效益较高,具有较好的推广价值。     

双回路中冷的柴油机冷却水系统

将用于机车柴油机的双冷却水回路增压空气中间冷却器（中冷器）和常用的单水回路中冷器冷却方式进行了对比,介绍双回路中冷的柴油机冷却水系统对机车、陆用发电机组等利用风扇来冷却柴油机和水的机组的好处,并分析其相应的系统原理。     

The potential of balloon engines to convert the low grade heat in warm, saturated air to electrical energy

This article outlines the concept, theory and performance of an engine for converting the heat in warm, saturated air to electrical energy. The engine comprises a drive balloon and a support balloon both connected to an electric generator by a rope. Warm, saturated air from a source such as a solar pond or the cooling tower of a power station is used to charge the larger drive balloon. The two balloons ascend several kilometers while performing work on the electric generator. At some maximum height the larger drive balloon discharges all its air into the cold upper atmosphere and, with the smaller balloon providing support for the larger balloon envelope, the two balloons are hauled back to ground by switching the electric generator to electric motor operation. The work done by the system on the electric generator during ascent exceeds the work done on the system by the electric motor during descent resulting in a positive work output. Condensation of water vapor in the drive balloon maintains the internal saturated air temperature above ambient temperature and provides an increasing lift force with height. Recycling the condensate adds to the work output of the engine and conserves water. The ideal thermal efficiency of the engine approaches 15%, corresponding to the large temperature difference available within the 10 km height of the troposphere. The engine power scales as the cube of the drive balloon diameter. Scaling by a factor of four up from the diameter of commercially available balloons provides power outputs in the MW range.     

Thermal behavior of lithium batteries used in electric vehicles using phase change materials

Electric vehicles equipped with lithium-ion batteries face a huge challenge, and the fact that battery life is very much affected by the temperature conditions of their operating environment, the heat reduces battery life cycle and time and increases the likelihood of thermal degradation and explosion. This problem has forced engineers to cool the battery. The methods used to cool the battery includes a cool water method (passing water or a dielectric fluid from the battery pack), cooling air (blowing air into the battery compartment by the fan), using a refrigeration system (such as cooling screens), and the use of phase-change material (PCM). In this research after reviewing and referring to valid authorities, it was found that PCMs are superior to all three other cooling systems because the air-conditioning system is not very desirable due to the high-temperature gradient between the battery cells. Also, cooling and refrigeration systems with refrigerant gases will also cost a very high cost on the electric car. The results of the studies showed that the cooling the battery using the PCM creates a similar temperature profile between the batteries in the battery pack, the temperature gradient is much smaller than the air cooler and cool water, and the final cost will be much lower. Also, it performs more efficiently in high-speed road dynamics and increases the battery life of an electric car or electric hybrid.     

某副机滑油温度高故障分析

针对某轮2号副机在高负荷运行时滑油温度较高故障,对相关原因进行筛查.在排除滑油温度控制阀和空冷器冷却水旁通阀本身问题的基础上,预判故障点在滑油冷却器上.对滑油冷却器的拆检证实其淡水进口被异物堵塞.清除淡水进口异物后,开机测试表明滑油温度正常,故障解决.     

带饮水机的多功能电冰箱设计

在传统电冰箱的基础上,另独立设置2个保温箱贮存冷热饮用水。冷水制取是在冷水箱中设置蒸发器,将冷水箱中的水制冷。热水制取是在热水箱中设置逆流套管式冷凝器,利用制冷系统的排热量将饮水机中的水加热到一定温度,如温度不够则再通过电加热器,可将饮用水加热至沸腾,冷凝管通热水箱后可采用风冷式和水冷却两种方式相结合。根据设计和理论计算,多功能电冰箱的冷凝器可将饮用水加热到65℃左右,再用电加热器,可将饮用水加热至沸腾,比市场上纯粹用电加热的饮水机可节电22.31W;利用制冷系统将冷水箱中的水制冷,每产生4℃冷饮用水2L比市场上一般的压缩式制冷饮水机可节约大约2.3×105J的能量。