回收垃圾填埋气发电的热气机燃烧系统研究

针对热气机连续燃烧的特点,采用稀薄燃烧和燃气再循环技术,开发了一套新型旋流扩散燃烧系统和燃烧控制逻辑,建立了利用热气机回收填埋气发电的试验系统,在垃圾填埋场进行了现场系统性能试验.结果表明,改装了燃烧垃圾填埋气燃烧器的热气机系统启动容易,对甲烷浓度适应范围广,燃烧完善,燃烧室内温度分布均匀合理,污染物排放低,并且实现了热气机发电系统无人值守运行.     

连接方式对自然循环太阳能热水系统的影响

以国标GB／T18708—2002《家用太阳热水系统热性能试验方法》为依据，针对自然循环平板式太阳能热水系统在连接方式不同的情况下，其热性能的差异进行了对比试验，并从自然循环系统循环动力——热虹吸压力的角度分析了两种连接方式下热性能差异的原因。     

一种热气机用盘式旋流气体燃烧器的试验研究

为满足小型热气机常温常压条件下燃烧的需要,在数值模拟的基础上设计了一种盘式旋流气体燃烧器,并试验研究了不同开孔方式、负荷条件和过量空气系数下燃烧室内的温度分布和火焰形状,结果表明:燃气孔为内孔,空气旋转流动,同时燃烧器外径减小到原来的2/5左右的情况下,燃气-空气混合均匀,燃烧稳定,火焰透明、脱壁且不直接灼烧加热器头部,高温区分布合适,满足热气机燃烧要求。     

自由活塞式热气机发电技术在世界上的发展

自由活塞式热气机是热气机的一个重要分支,也是一个非常活跃的研究领域。当前世界上已有数家公司正在研究和生产商品化的自由活塞式热气机,而目前发展较好的公司为美国的SunPower公司和Infinia公司。自由活塞式热气机可应用在太阳能发电系统、太空核动力发电系统、战场小型动力系统、士兵可佩带动力系统和家用的MCHP等领域,体现出良好的市场发展前景。     

电加热器故障在线监测系统开发

针对传统的恒温恒湿设备电加热器出现故障时无法自动判断原因,设备结构复杂,拆装不便,严重影响汽车发动机试验开发效率等问题,自主开发设计了电加热器故障在线监测系统,该系统对工作中的电加热器电流进行监测,实时分析电加热器的工作状态。电加热器工作时,系统对电加热器的电流进行监测,当电流波动范围超出允许范围时,系统报警提示,电加热器显示故障。     

浅谈家用太阳热水器热性能测试

如何评价与检测家用太阳热水器的热性能呢？国家质量监督检验检疫总局于2002年4月28日发布了国标GB／T 18708—2002《家用太阳热水系统热性能试验方法》，通过此试验方法可得到太阳热水器能量输入一输出曲线图，它全面系统地反映了在不同的季节、不同的太阳辐照量条件下的太阳热水器能量输入一输出特性，实现了我国太阳热水器产品的热性能试验与国际接轨。     

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。     

太阳能热水系统多天热性能试验

一引言家用太阳能热水系统多天热性能的测试方法,国内主要依据标准GB/T18708—2002《家用太阳热水系统热性能试验方法》,国际上主要依据     

太阳能热水系统热性能计算可视化软件的开发

热性能是家用太阳热水系统重要的质量指标,是可以直接决定系统合格与否的主要因素.本文依据反射器的类型,对太阳热水系统进行系统分类,并采用Visual Basic编程,开发不同类型的家用太阳能热水系统热性能计算软件,该软件计算准确,使用方便,它的可视化界面,能够有效的实现人一机对话.     

基于蒸汽喷射式热泵的火电厂除氧器乏汽回收系统热经济性分析

针对火电厂汽轮机回热系统中的工质损失和热损失,以某电厂600MW机组为例,对采用蒸汽喷射式热泵将除氧器乏汽回收到低压加热器中的节能技术进行研究,利用等效焓降法对各个节能方案的热经济性指标进行了计算,并对不同节能方案的热经济性进行了比较.结果表明:除氧器乏汽通过蒸汽喷射式热泵回收到5号低压加热器(方案4)的节能效果最显著,经济效益最好.与原方案相比,采用方案4,每发1度电平均可以节约标准煤0.3g,按机组年运行5 500h计算,每年可以节约标准煤990t.     

The impact of heat exchanger fouling on the optimum operation and maintenance of the Stirling engine

This paper focuses on the effect of heat exchanger fouling on the performance of the Stirling engine in combined heat and power (CHP) application. Fouling results from using biomass fuels and affects the heat exchanger that transfers heat into the engine. This heat exchanger is referred to as the heater. The heat exchanger that recovers heat from the flue gases is also affected by fouling. To determine the performance of the Stirling engine, a commercial Stirling analysis tool is applied together with models that have been developed for the heat transfer in the heater, regenerator and cooler of the engine. The Stirling engine model uses constant temperatures for the heat addition and rejection, with the theory of displacement engine as a basis. The fouling in the heat exchanger is taken into account by using a fouling factor that corresponds with the degradation in the total heat transfer coefficient. The Stirling engine model together with the model for heat exchanger fouling makes it possible to estimate the effect of fouling on the performance of the Stirling engine. A cost model is developed for the engine to translate changes in performance into economy in CHP operation. In the studied application, the Stirling engine is operated by the heat demand. Together with the selected control method, performance and cost models compose a tool for the simulation and optimization of the system. The use of the models to determine the optimal cleaning interval of the heat exchanger surfaces is considered.     

Performance of a twin power piston low temperature differential Stirling engine powered by a solar simulator

This paper provides an experimental investigation on the performance of a low-temperature differential Stirling engine. In this study, a twin power piston, gamma-configuration, low-temperature differential Stirling engine is tested with non-pressurized air by using a solar simulator as a heat source. The engine testing is performed with four different simulated solar intensities. Variations of engine torque, shaft power and brake thermal efficiency with engine speed and engine performance at various heat inputs are presented. The Beale number, obtained from the testing of the engine, is also investigated. The results indicate that at the maximum simulated solar intensity of 7145 W/m², or heat input of 261.9 J/s, with a heater temperature of 436 K, the engine produces a maximum torque of 0.352 N m at 23.8 rpm, a maximum shaft power of 1.69 W at 52.1 rpm, and a maximum brake thermal efficiency of 0.645% at 52.1 rpm, approximately.     

Beta-type Stirling engine operating at atmospheric pressure

In this study, a beta-type Stirling engine, with a 192 cc total swept-volume, was manufactured and its performance tested at atmospheric pressure. The hot-source temperature is chosen as a fundamental parameter of the experimental study. Experiments were performed with an electrical heater at 800, 900 and 1000 °C temperatures. Torque and output-power variations were obtained for different engine speeds. The test engine reached a maximum of 5.98 W at 208 rpm, at the hot-source temperature of 1000 °C.     

发动机低温起动加温锅性能匹配研究

为进行发动机低温起动加热系统加温锅性能匹配,采用AMESIM软件建立了某发动机加热系统模型,研究了不同的加热功率对发动机起动性能的影响。结果表明：存在一个满足起动性能要求的最小的加热功率,同时也存在使起动准备时间最短的最佳加热功率。其结论对匹配加温锅功率具有一定的参考价值。     

空气源热泵热水器在寒冷地区冬季的能效分析

对一台家用空气源热泵热水器进行冬季性能测试,研究室外空气温度、水箱温度不同时机组性能变化。基于测试数据分析影响机组性能的敏感因素,依据所得天津地区实测数据分析其冬季平均能效。结果表明：COP最低为1.30,具有节能效果;保证用水舒适度及机组运行稳定的情况下,45 ℃为水箱最佳设定温度;室外空气温度偏移较水箱平均温度偏移对系统性能更敏感;测试工况下热泵机组单独工作和启动电辅加热时全冬季的平均能效相差甚微,若用户设定机组在日最高温度时段开启加热,能获得更好的节能效果。     

Development and test of combustion chamber for Stirling engine heated by natural gas

The combustion chamber is an important component for the Stifling engine heated by natural gas. In the paper, we develop a combustion chamber for the Stifling engine which aims to generate 3-5 kWe electric power. The combustion chamber includes three main components： combustion module, heat exchange cavity and thermal head. Its feature is that the structure can divide ＂combustion＂ process and ＂heat transfer＂ process into two appar- ent individual steps and make them happen one by one. Since natural gas can mix with air fully before burning, the combustion process can be easily completed without the second wind. The flame can avoid contacting the thermal head of Stifling engine, and the temperature fields can be easily controlled. The designed combustion chamber is manufactured and its performance is tested by an experiment which includes two steps. The experi- mental result of the first step proves that the mixture of air and natural gas can be easily ignited and the flame burns stably. In the second step of experiment, the combustion heat flux can reach 20 kW, and the energy utiliza- tion efficiency of thermal head has exceeded 0.5. These test results show that the thermal performance of com- bustion chamber has reached the design goal, The designed combustion chamber can be applied to a real Stifling engine heated by natural gas which is to generate 3-5 kWe electric power.     

The investigation of the effect of thermal barrier coating on the performance of Stirling engine

The shuttle heat transfer is one of the reasons reducing the performance of Stirling engines. This study is concerned with the reduction in shuttle heat transfer by coating the displacer. The displacer of a gamma type Stirling engine was coated with a layer of yttria‐stabilized zirconia (YSZ), and the effect of the coating on the engine performance was evaluated by comparing speed‐power and speed‐torque characteristics of the engine with coated and uncoated displacers. Characteristics were obtained for 700, 800 and 900°C heater temperatures. At each stage of the heater temperature, the charge pressure ranged from 1 to 3.5 bars with 0.5 bar increments. At 900°C heater temperature and 3 bars charge pressure, the shaft power before coating was 34.9 W, after coating the power increased to 43.8 W, which corresponds to a 25% increment. The temperature applied to the engine did not cause any damage on the coating layer. Copyright © 2008 John Wiley & Sons, Ltd.     

A four power-piston low-temperature differential Stirling engine using simulated solar energy as a heat source

In this paper, the performances of a four power-piston, gamma-configuration, low-temperature differential Stirling engine are presented. The engine is tested with air at atmospheric pressure by using a solar simulator with four different solar intensities as a heat source. Variations in engine torque, shaft power and brake thermal efficiency with engine speed and engine performance at various heat inputs are presented. The Beale number obtained from the testing of the engine is also investigated. The results indicate that at the maximum actual energy input of 1378 W and a heater temperature of 439 K, the engine approximately produces a maximum torque of 2.91 N m, a maximum shaft power of 6.1 W, and a maximum brake thermal efficiency of 0.44% at 20 rpm.     

Sizing analysis of a combined cooling,heating, and power system for a small office building using a wood waste biomass‐fired Stirling engine

When wood chips are available and used to fuel a combined cooling, heating, and power (CCHP) waste heat recovery system, they can represent an economically viable source of biomass energy that can meet a facility's electric and thermal demands. Using a Stirling engine as the CCHP prime mover provides several important advantages over conventional internal combustion engines including no additional processing of the waste wood chips, a potentially higher thermal efficiency, flexibility of fuel sources, and low maintenance. This study shows how the operational characteristics of a constant output, biomass‐fired, Stirling engine‐based CCHP system are affected by the performance of the individual components, including the prime mover, heat recovery system, auxiliary boiler, absorption chiller, and heating coil unit The results are assessed by examining the primary energy consumption and operational cost compared with a reference case. The analysis provides insight on the prime mover sizing and selection of each component to properly implement the system. In addition to examining the effects of each component, the effect of excess electricity production and buyback are considered. Copyright © 2010 John Wiley & Sons, Ltd.     

斯特林发动机管式加热器内振荡流动的换热特性实验研究

模拟管式加热器在斯特林发动机中的工作状态,研究加热器管内工作气体振荡流动的换热特性,得到气体压力、振荡频率等对换热的影响规律,进一步得到工作气体与管壁间的平均换热系数,并将结果转化为无量纲参数,比较稳定流动换热关联式计算结果与实验结果的偏差。实验结果可对斯特林发动机管式加热器设计、优化和换热性能预测提供参考。