应用数值模拟进行均热炉换热器的节能研究

均热炉应用金属换热器代替传统的非金属陶土换热器,可以提高换热效率,降低均热炉燃气消耗。文章通过数值模拟试验,研究了换热器改造后的流场和温度场,进一步验证了节能改造的可行性。     

车用液化天然气加热器性能的试验研究

对天然气加热器进行了台架试验。因气态燃料极易与空气混合燃烧,故不易在热交换器内壁产生积炭和烟灰,其热效率比燃油加热器高10%以上。为了消除高温燃气因流动短路而造成的热损失,尝试了在热交换器肋片出口端面增加燃气均流环并进行了试验。另外,为了削弱热辐射及传导所造成的热能流短路损失,还做了在燃烧室外加装遮热筒试验,其试验效果显著。     

车用液化天然气加热器性能的试验研究

对天然气加热器进行了台架试验。因气态燃料极易与空气混合燃烧,故不易在热交换器内壁产生积炭和烟灰,其热效率比燃油加热器高10%以上。为了消除高温燃气因流动短路而造成的热损失,尝试了在热交换器肋片出口端面增加燃气均流环并进行了试验。另外,为了削弱热辐射及传导所造成的热能流短路损失,还做了在燃烧室外加装遮热筒试验,其试验效果显著。     

提高天然气均热炉热效率的节能改造

文章针对特殊钢分公司均热炉能源利用水平不高、热资源未得到充分利用的问题，通过对11#均热炉热效率测试、分析，找出能耗偏高的主要原因，并对换热器、炉盖等设备实施改造。改造后燃气单耗明显下降，热效率提高4％，取得了较好的节能效果。     

换热技术从大型化向微小化的发展

在分析传统换热器结构特点的基础上,具体分析了目前常用紧凑式换热器的结构、性能及应用情况,阐述了微型化学（化工）机械系统的发展及应用情况。以氨冷器为例,分别进行了板翅式换热器和另一种高效的小型换热装置——热管换热器的设计,表明板翅式换热器具有更加高效的换热效率和紧凑的结构,由此综合说明了换热技术从大型化向紧凑化、微小化发展的必然趋势。进一步以典型的微型化换热器装置——微通道换热器、微通道蒸发器和微通道加热器为例,具体分析了微型换热技术广阔的应用前号。     

一种小型蒸发式车用液暖燃油加热器性能试验分析

对一小型蒸发式车用液暖燃油加热器,分别做了燃烧室温度场测量,电磁泵不同供油频率(油量)性能对比;水流量对热效率的影响及循环水泵性能试验等。通过以上试验,对该型号加热器性能有了一个比较全面的认识。     

红套环加热装置设计、试验及应用

文章通过对红套环安装及拆卸需求的分析,设计出了满足红套环安装及拆卸的加热器,并通过对加热器通入燃气的燃烧性能试验、用加热器加热红套环与试验件的装配及拆卸试验,以及在汽缸水压试验中的成功应用,验证了该装置的可靠性及实用性.     

影响家用燃气灶具热效率测试因素的探讨

介绍了燃气灶具风门开度变化、燃气压力变化、试验热负荷的选择以及试验操作方法等因素对热效率测试的影响，通过相关试验进行分析与探讨，指出在测试时应避免这些因素对燃气灶具热效率测试的影响。     

中欧实验室燃气采暖热水炉能效一致性分析

为了对比中欧燃气采暖热水炉实验室检测水平的一致性,选取1台某品牌试验样机,分别在欧洲实验室、该品牌国内实验室和国家燃气用具质量监督检验中心实验室进行热效率检验,并根据燃气采暖热水炉的热平衡及效率计算公式计算试验样机的理论热效率。以实测热效率作为参加结果,以理论计算热效率作为参考值,采用Z比分数方法对测试结果进行分析。结果显示,3个实验室的|Z|均小于2,能力判定均为满意,即3个实验室的能效检测水平和检验数据一致性较好,实验室之间的差异较小。     

空调系统排风热回收换热器的试验研究

对用于回收空调系统余热的通风换热器进行了试验研究。在冬季工况下对其进行了性能测试。试验结果表明，该换热器具有换热效率高、阻力小的特点；在风速为2．6m/s的工况下，其换热效率达到64．5％。     

Experimental study on titanium heat exchanger used in a gas fired water heater for latent heat recovery

In general, latent heat recovery is usually accompanied by the corrosion of the heat exchanger, which is caused by the strongly acidic condensate when the temperature of the flue gas is lowered below the acid dew point. The present study has been conducted to investigate the heat and mass transfer characteristics in a titanium heat exchanger with excellent corrosion resistance used for waste heat recovery with the condensation arranged in a gas fired water heater. In addition, the thermal efficiency of the gas fired water heater was evaluated based on the net calorific value at the maximum rated output during latent heat recovery from the exhaust flue gas. Parametric studies were conducted for the flue gas flow rate, inlet temperature and mass flow rate of the supplied water, respectively. Different arrangements of the tubes of the heat exchanger including in-line and staggered configurations were investigated. The experimental results indicate that the thermal efficiency of the gas fired water heater with a latent heat recovery (LHR) heat exchanger was enhanced by about 10% compared with conventional instantaneous water heaters, i.e., water heaters without heat recovery. In addition, in terms of the Nusselt number and the Sherwood number, the heat and mass transfer performance of the staggered tube bank type were approximately 50% and 10% higher than that on the in-line tube bank type when the Reynolds number of the flue gas was 10³.     

Experimental investigation on thermal performance of thermosyphon flat-plate solar water heater with a mantle heat exchanger

The thermal performance of thermosyphon flat-plate solar water heater with a mantle heat exchanger was investigated to show its applicability in China. The effect on the performance of the collector of using a heat exchanger between the collector and the tank was analyzed. A “heat exchanger penalty factor” for the system was determined and energy balance equation in the system was presented. Outdoor tests of thermal performance of the thermosyphon flat-plate solar water heater with a mantle heat exchanger were taken in Kunming, China. Experimental results show that mean daily efficiency of the thermosyphon flat plate solar water heater with a mantle heat exchanger with 10 mm gap can reach up to 50%, which is lower than that of a thermosyphon flat-plate solar water heater without heat exchanger, but higher than that of a all-glass evacuated tubular solar water heater.     

Application and Research Progress of Heater in Natural Gas Industry

With high-speed development, the natural gas industry will lead and promote the development of related techniques and equipments. This article studies the application of the heater in the gas industry, and indicates that it is an indispensable piece of equipment in natural gas application systems. As a special furnace type, the natural gas heater is the main energy consumer for the process of gas production, transportation, and application. Thus, the development of highly efficient natural gas heaters has become an important research aspect. Investigations and improvements on the structure and heat-transfer process of the heater in order to improve its thermal efficiency are discussed in this article. It is concluded that as a weak point, the heat transfer effect inside the natural gas heater needs to be improved. A simple and effective improved structure of a diversion-type natural gas heater is put forward, so as to help the heat transfer medium form an organized flow and enhance the heat transfer, thus improving the thermal efficiency of the natural gas heater and saving energy considerably. This technology has been awarded a patent in China.     

A run-around heat exchanger system to improve the energy efficiency of a home appliance using hot water

A significant portion of the energy consumed by many home appliances using hot water is used to heat cold supply water. Such home appliances generally are supplied water at a temperature lower than the ambient temperature, and the supply water is normally heated to its maximum operating temperature, often using natural gas or an electrical heater. In some cases, it is possible to pre-heat the supply water and save energy that would normally be consumed by the natural gas or electrical heater. In order to save the energy consumed by an appliance using water heater, a run-around heat exchanger system is used to transfer heat from the ambient to the water before an electrical heater is energized. A simple model to predict the performance of this system is developed and validated, and the model is used to explore design and operating issues relevant to the run-around heat exchanger system. Despite the additional power consumption by the fan and pump of the run-around heat exchanger system, the experimental data and analysis show that for some systems the overall energy efficiency of the appliance can be improved, saving about 6% of the energy used by the baseline machine.     

折流杆换热器在火力发电厂低压加热器上的应用

简述了折流杆换热器在火力发电厂低压加热器上的应用,其优点表现在传热效果好,流体阻力小,换热器抗腐蚀性、抗冲击性、抗振性增强。可以在发电厂回热系统中推广应用。     

新建炼厂设计阶段提高加热炉热效率的措施

在炼油加工过程中,加热炉是能耗大户.对新建炼厂,在设计阶段提高加热炉热效率,对节能减排有重要意义.在设计过程中,采取燃料气脱硫等措施以降低排烟温度、降低空气过刹系数和漏风量等措施以降低过剩空气量、优化设计加热炉衬里以降低散热损失、优化余热回收系统方案和控制方案以提高烟气余热利用率和操作稳定性、利用装置废热预热助燃空气,...     

脱硝尿素热解系统炉内烟气换热器运行分析及设计优化

脱硝尿素热解制氨系统一般通过电加热器提供所需的高温热解空气热量,采用锅炉烟道内布置烟气换热器,可以有效提供高温热解空气加热所需热量,降低电加热器运行功率从而节省高品质电能.通过对某350 MW机组实际运行数据分析,总结锅炉内置烟气换热器尿素热解系统的运行特点,提出烟气换热器优化设计方案,保证尿素热解制氨系统的运行经济性...     

天然气热风炉在干燥行业中的节能应用

介绍了天然气直燃热风炉在干燥行业的节能应用。采用天然气直燃热风炉代替蒸汽换热装置,可大幅提高干燥系统的热效率,节能效果显著。通过对某生物制药公司干燥系统的改造实践,取得了比较满意的改造效果。改造后,干燥介质温度可达到180℃以上,出力稳定,使设备生产能力提高20%。另外,干燥介质的温度可以根据生物质饲料所含水分自动调节,确保了干燥品质。系统热效率由改造前的44%提高到96%以上。     

Study on the heat-flow controllable heat exchanger (1st report): Thermal characteristics of heat-flow controllable heat exchanger

To regulate temperature in passive solar houses and green houses, the authors have developed a heat exchanger capable of controlling the heat flow. It has a thermal switch mechanism without mechanically moving parts. It consists of an evaporator, a condenser, a vapor passage pipe, a liquid return pipe having an inverted-U-pipe, and a heater mounted on the inverted-U-pipe. The heat exchanger can transfer, or reduce to zero, heat from the evaporator to the condenser by regulating a slight heater input. The authors have fabricated a model of the heat-flow controllable heat exchanger to examine its thermal switching and heat exchange characteristics, and then compared the obtained results with calculation results. It was clarified that the experimental results agree with the calculation results.