柴油机功率修正误差分析

本文在分析柴油机功率修正公式的基础上给出了判断修正误差的方法,并对处理修正误差问题提出了建议。     

柴油机功率修正误差分析

本文在分析柴油机功率修正公式的基础上给出了判断修正误差的方法,并对处理修正误差问题提出了建议。     

大陈岛风力发电机与柴油发电机联运系统的静态模拟计算

对浙江省大陈岛上的用电情况进行了统计分析,并对现存的及将要安装的风/柴系统进行了静态模拟计算,提出了确定装机容量的两个判别准则。在现有的大陈岛的柴油发电系统中,采用风/柴系统联合供电是经济合理的,最佳的风力机装机容量为100—120kW。     

一起柴油发电机出口开关异常跳闸的原因分析

柴油发电机作为发电厂厂用电的应急保安电源,是保证厂用电安全运行的最后一道防线.介绍了柴油发电机的工作原理,结合某电厂柴油发电机出口开关异常跳闸的案例,分析了柴油发电机带载试验时出口开关异常跳闸的原因,并提出了优化建议.     

事故柴油发电机的容量选择

本文介绍了通过确定一级负荷设备各台电机的起动和运行负荷参数,并计算出总的一级负荷设备的起动和运行负荷,以便能经济合理地选择事故柴油发电机的容量。     

柴油发电机与天然气内燃机在数据中心的应用

结合数据中心负荷需求和燃料特性,比较了柴油发电机与天然气内燃机的异同及优劣,并探讨了柴油发电机燃用天然气改造的可行性。     

12000-DE柴油发电机积极隔振的试验研究

通过不同减振器的减振试验,测量发电机的振动特性,对试验数据进行分析比较,从中优选出减振器,并运用于实际的隔振工程。在理论上讨论了试验结果的合理性。分析该装置的特点,总结了隔振试验中应该注意的事项,并提出改进措施,对今后柴油发电机的隔振试验和实际工程具有指导意义。     

12000-DE柴油发电机积极隔振的实验研究

为对12000-DE柴油发电机进行振动控制,该文通过JZ-30减振器的隔振实验,测量了发电机的振动特性,对隔振效果进行了比较,并运用于实际的隔振工程,起到很好的效果。在文中分析了该装置的特点,总结了隔振实验中应该注意的事项,并提出了改进措施,对今后柴油发电机的隔振实验和实际工程具有一定的借鉴意义。     

往复式压缩机空冷器加装保温棉提高外输气温度的实践

介绍往复式压缩机的参数和工作概况,针对冬季3台往复式压缩机组频繁停机问题,分析造成压缩机出口排气温度过低的原因;提出通过加装保温棉、控制空冷器的风量来进行改进,以达到提升压缩机的排气温度,保证机组正常运行。     

红外热像仪的最大测温误差分析

根据红外辐射理论和红外热像仪的测温原理,考虑环境,大气,太阳等多方面影响,得出最大测温误差的计算公式,通过分析各种因素对热像仪测温误差的影响程度,讨论了减小误差的对策。     

SPC技术在柴油机排放测量中的应用

将SPC统计技术应用于实验室测量系统,介绍排放测量过程控制的具体步骤和方法,以期推动测量过程控制新技术的应用。     

Stability analysis of distributed parameter systems on temperature measurement of large-scale objects

In this paper,the mechanical construction,thermal regulator design and temperature measurement system of alocal area were set up for large-scale linear measurement.Numerical analysis based on temperature correlatedcharacteristic is discussed to obtain optimal observation points for the measurements.The horizontal temperaturedistribution of the measured area is compared with the measurement of the variation of temperature at 15℃ and20~C over time,and characteristic of dynamic response is also discussed.In addition,the long-time stability ofmeasured temperature is analyzed by means of using the standard deviation.It characterizes the temperature dis-tribution performance of a large area and how it may impact the measurement of a large-scale object.     

Non-invasive measurement of the human core temperature

The direct measurement of the temperature of the human body core, while being of great significance for the evaluation of patient health, is inconvenient. This realization has motivated attempts to measure the core temperature indirectly, for the most part at locations which do not require invasion of the body. In the investigation described here, a new approach to noninvasive measurement of the core temperature is set forth. The site of the proposed measurement is on the forehead where the anatomy is relatively uniform amongst individuals and also well established to be modeled accurately. The approach described here consists of simple hardware and a logic-based and customized control algorithm.The connection between the core temperature, the sensor temperature, and the temperature of a sensor-system heater was determined by numerical simulations of the heat transfer in the tissue bed fronted by the forehead skin and backed by the frontal bone. For heat transfer through each tissue layer in the tissue bed, the bioheat equation was employed, while for a resistance element in the sensing system, the Fourier heat conduction equation was used. These were solved in the transient mode. The controller read the temperatures of the core, the sensor, and the ambient, and the algorithm instructed the sensor-system heater to obtain a specific temperature value. The iterative use of the control algorithm resulted in near-equality of the sensor and core temperatures.An optimization routine performed operations needed to find the best performing sensor system. After optimization, that system is capable of yielding core temperature results that are approximately in error by 0.2 °C.A model problem was formulated to assess the capabilities of the sensing system to follow a time-varying core temperature. It was found that for core temperatures that varied by 0.05 °C per minute, the sensor followed the core within 0.2 °C or better.     

Influence of Participating Media on the Radiation Thermometry for Surface Temperature Measurement

A temperature measurement model of radiation thermometry for the surface covered by participating media was developed. The model was based on the radiation heat transfer of participating media and principles of radiation pyrometers, and solved by integral formulation of discrete ordinate method on spectral waveband. The influence of water mist on the indicated temperature of Raytek MR1SB one/two color pyrometer was discussed. Mie theory was used to calculate the radiative properties of water mist. In order to verify the model, a laboratory temperature measurement experiment was executed. The result shows that temperature of radiation thermometry is sensitive to the spectral response wavelength of pyrometer, and the simulated temperature of pyrometer agrees well with the experimental measurements on a suitable wavelength. The simulated temperature was lower than the real temperature of surface for one-color pyrometer, and it could be higher or lower than the real one for two-color pyrometer with the influence of participating media.     

Effect of some BED blends on the equivalence ratio, exhaust oxygen fraction and water and oil temperature of a diesel engine

Nowadays, natural-based oxygenated fuels, especially biodiesel and ethanol, have been considered as substitutes for fossil fuels. Because of relatively lower energy content of oxygenated fuels, it is necessary to blend them with fossil ones. In this research, authors conducted an investigation on some BED blends to determine and compare their effects on equivalence ratio, exhaust oxygen fraction and water and oil temperature in a diesel engine. For this purpose, 18 different blendes of ethanol and biodiesel with net diesel fuel were tested in a MT4-244 engine¹ considering two engine speeds in full load condition. In almost all samples the equivalence ratio decreased with increasing of biodiesel and ethanol percents. Exhaust oxygen fraction in all of samples increased with increasing of biodiesel and ethanol percents, whereas the engine water and oil temperatures slightly reduced.     

150型柴油机气缸套温度场有限元分析

针对150型柴油机热负荷问题,以实测温度场数据为基础,确定了气缸套的换热边界条件,建立了完整的气缸套温度场计算模型。运用有限元法分析了150型柴油机标定工况下气缸套三维温度场及热变形。分析结果表明：最高温度为209℃,位于气缸套内壁上端;最大径向变形量为0．244mm,位于气缸套上端。     

Effect of exhaust gas recirculation (EGR) temperature for various EGR rates on heavy duty DI diesel engine performance and emissions

DI diesel engines are well established today as the main powertrain solution for trucks and other relevant heavy duty vehicles. At the same time emission legislation (mainly for NO_x and particulate matter) becomes stricter, reducing their limit to extremely low values. One efficient method to control NO_x in order to achieve future emissions limits is the use of rather high exhaust gas recirculation (EGR) rates accompanied by increased boost pressure to avoid the negative impact on soot emissions. The method is based on the reduction of gas temperature level and O₂ availability inside the combustion chamber, but unfortunately it has usually an adverse effect on soot emissions and brake specific fuel consumption (bsfc). The use of high EGR rates creates the need for EGR gas cooling in order to minimize its negative impact on soot emissions especially at high engine load were the EGR flow rate and exhaust temperature are high. For this reason in the present paper it is examined, using a multi-zone combustion model, the effect of cooled EGR gas temperature level for various EGR percentages on performance and emissions of a turbocharged DI heavy duty diesel engine operating at full load. Results reveal that the decrease of EGR gas temperature has a positive effect on bsfc, soot (lower values) while it has only a small positive effect on NO. As revealed, the effect of low EGR temperature is stronger at high EGR rates.     

空预器排烟温度高的原因及解决措施

某电厂3#机组在试运行期间存在空预器排烟温度高于设计值的问题,影响了锅炉的安全经济运行。针对这一问题,进行深入分析,找出影响因素,并提出一系列解决措施,从一定程度上解决了排烟温度偏高的问题。