基于测温环测温技术的玻璃实验室温控设备控温监测

玻璃实验室高温设备控温的关键指标是控温均匀性与控温稳定性。现有测温技术中,多数测温手段在时间和空间上均受到一定限制,难以测量不同保温时间与不同空间方位的累积热效应控温精度。据此,介绍运用测温环测温技术,监测玻璃实验室温控设备控温效果,保证其控温稳定性与均匀性。本方法也可推广到玻璃窑炉工业或者其他行业的高温控温监测。

在真空退火炉中用测温环校温

真空退火炉测温受影响因素多,使用测温环对真空退火炉在控温点进行校准,校准后仪表显示温度与炉内均温区实际温度区域相近。

使用测温环测试炉温均匀性

0引言对箱式电阻炉、固化炉等热处理设备进行温度均匀性测试,一般采用热电偶作为测温元件。但部分设备没有预留测温通道,炉体内测温热电偶的热电势信号无法采集,无法使用通用的测试方法。本文尝试采用测温环作为测温元件进行炉温测试,作为一种应急备选方案。

钟罩窑内温度分布测定及其对产品性能的影响

采用新型测温环测温法,对工业钟罩窑内的温度分布进行了系统测定,结合烧成品的物性测定,研究了温度分布对陶瓷产品质量的影响,并对实际焙烧过程提出了改进建议,获得了良好的效果。

Key Environmental Factors Monitoring System of Low-power Greenhouse Based on WSN Technology

A low-power environmental monitoring system based on WSN technology is proposed to effectively monitor the environmental status and ensure the healthy growth of greenhouse crops in the greenhouse. The system performs dynamic mon- itoring on the environmental data of temperature, humidity, illumination, soil tempera- ture and humidity of the greenhouse, and it reduces the energy consumption by us- ing solar energy and lithium battery as the power supply mode and dynamic power management algorithm combined with improved routing protocol. Stable and reliable, the system could effectively monitor the key environmental factors in the green- house, making it of certain promotion value.

Establishment of Reverse-transcription Loopmediated Isothermal Amplification Method for Detection of Wheat Streak Mosaic Virus

A reverse-transcription loop-mediated isothermal amplification （RT-LAMP） method was established for the detection of wheat streak mosaic virus （WSMV）. Ac-cording to the conservative regions of the genes that encode the coat protein of WSMV, 2 pairs of primers were designed. Final y, the 1st pair of primers was select-ed through the specificity test. The sensitivity test showed the sensitivity of RT-LAMP method was 10 times higher than that of RT-PCR. In addition, the amplifica-tion of target gene could be judged visual y from the presence of fluorescence （cal-cein） in the final reaction system. The RT-LAMP method, established in this study, was rapid, easy, specific and sensitive. Moreover, it did not require sophisticated equip-ment. The RT-LAMP was suitable for the rapid detection of WSMV.

Outlet Temperature Correlation and Prediction of Transfer Line Exchanger in an Industrial Steam Ethylene Cracking Process

Predicting the best shutdown time of a steam ethylene cracking furnace in industrial practice remains a challenge due to the complex coking process. As well known, the shutdown time of a furnace is mainly determined by coking condition of the transfer line exchangers （TLE） when naphtha or other heavy hydrocarbon feedstocks are cracked. In practice, it is difficult to measure the coke thickness in TLE through experimental method in the complex industrial situation. However, the outlet temperature of TLE （TLEOT） can indirectly characterize the coking situation in TLE since the coke accumulation in TLE has great influence on TLEOT. Thus, the TLEOT could be a critical factor in deciding when to shut down the furnace to decoke. To predict the TLEOT, a paramewic model was proposed in this work, based on theoretical analysis, mathematic reduction, and parameters estimation. The feasibility of the proposed model was further checked through industrial data and good agreements between model prediction and industrial data with maximum deviation 2% were observed.

Health monitoring and comparative analysis of time-dependent effect using different prediction models for self-anchored suspension bridge with extra-wide concrete girder

The structural health status of Hunan Road Bridge during its two-year service period from April 2015 to April 2017 was studied based on monitored data.The Hunan Road Bridge is the widest concrete self-anchored suspension bridge in China at present.Its structural changes and safety were evaluated using the health monitoring data,which included deformations,detailed stresses,and vibration characteristics.The influences of the single and dual effects comprising the ambient temperature changes and concrete shrinkage and creep(S&C)were analyzed based on the measured data.The ANSYS beam finite element model was established and validated by the measured bridge completion state.The comparative analyses of the prediction results of long-term concrete S&C effects were conducted using CEB-FIP 90 and B3 prediction models.The age-adjusted effective modulus method was adopted to simulate the aging behavior of concrete.Prestress relaxation was considered in the stepwise calculation.The results show that the transverse deviations of the towers are noteworthy.The spatial effect of the extra-wide girder is significant,as the compressive stress variations at the girder were uneven along the transverse direction.General increase and decrease in the girder compressive stresses were caused by seasonal ambient warming and cooling,respectively.The temperature gradient effects in the main girder were significant.Comparisons with the measured data showed that more accurate prediction results were obtained with the B3 prediction model,which can consider the concrete material parameters,than with the CEB-FIP 90 model.Significant deflection of the midspan girder in the middle region will be caused by the deviations of the cable anchoring positions at the girder ends and tower tops toward the midspan due to concrete S&C.The increase in the compressive stresses at the top plate and decrease in the stresses at the bottom plate at the middle midspan will be significant.The pre-deviations of the towers toward the sidespan and pre-lift of the midspan girder can reduce the adverse influences of concrete S&C on the structural health of the self-anchored suspension bridge with extra-wide concrete girder.

The Maximum Temperatures （Tmax） Distribution on the Body Surface of Sport Horses

The objective of the study was to determine the usefulness of measuring maximum temperatures in designated regions of a healthy horse＇s body surface. Thermographic investigations （Thermovision〉550, FLIR） were carried out on 35 horses from 6 to 16 years old participating in show jumping competitions. The rectal temperatures of the horses were in the range 37.5-38.2 ℃. The research was performed in a stable, the ambient temperature （Tab） of which was 14℃ with a humidity （φ） of 60%. Thermograms of the left and right side of the horses were obtained. Each thermogram consisted of 36 body surface regions （before the competition） and 25 regions （immediately after the competition）. The maximum temperature ranges at rest were 21.8 ℃-31.0℃ and symmetrical regions did not differ statistically （P 〉 0.05）. The highest temperatures were on the head, neck and trunk, the lowest-on the limbs. The hind legs were warmer than the front legs in analogous areas, with the exception of the gaskin and forearm. The warmest body areas had the largest surface area, which is indicative of their crucial role in the thermoregulation of the equine organism. The research results may therefore be useful in veterinary diagnosis. The range of maximum temperatures after the competitions was 25.2℃-34.2℃. The highest increment was observed at the breast, elbow, forearm and gaskin, the lowest-at the head, pastern and hoof （foreand hind limbs）. Research regarding body surface temperature after exercise does not have diagnostic value for veterinarians because ＂warming-up＂ certain parts of body surface masks inflammation.

Reverse Transcription-loop-mediated Isothermal Amplification for Detection of Maize Chlorotic Mottle Virus

Maize chlorotic mottle virus （MCMV） is a quarantine pest as approved by Chinese government： A rapid, sensitive and specific MCMV detection method using reverse transcription-loop-mediated isothermal amplification （RT-LAMP） was established in this study. Based on the sequence of MCMV coat protein coding gene, 3 sets of primers were designed and specificity test showed that the second set of primers was specific to MCMV, Similar sensitivities were observed on RT-LAMP and RT-PCR, except that RT-LAMP was quicker, and the reaction could be finished within 1 h. In addition, the presence or absence of the fluorescence under daylight allows naked easy detection of the amplification of MCMV genomic RNA using calcein. The RT-LAMP assay was applied successfully to detect MCMV in maize seeds, and the result by the addition of calcein was consistent with the result detected by the real time turbidimeter. The method is rapid, specific, sensitive without the need for complicated equipment, and is suitable for rapid field detection of MCMV.

Influencing factors of infrared surveying in roadway

The main factors that affect infrared surveying in roadway include that property of rock, electromechanical equipments running, environmental temperature, hydrogeology and support material etc. This paper sums up the expression features of these disturbing factor through theoretical analysis and actual measurement contrasts and considers that some tunnel section does not suit to go on infrared survey, for instance, soft rock meets water to expanse, and surround rock has obviously pouring water. The basic methods had made evading disturbing of electromechanical equipments, environmental temperature and protect material etc to become possible. It is helpful that offers infrared surveying technical service for production safety better in roadway.

Application Research on Toughness Index CTOD in Design of Railway Steel Bridge

Railway steel bridge belongs to large-scale weld structures suffered with cyclic dynamic stress generated by the train. In recent years, the section of bridge member becomes bigger, plate becomes thicker, connection form becomes more complicated and steel bridge is applied to wider districts even in the lower temperature environment. Thus, fatigue and fracture problems become more serious. On the basis of CTOD （crack tip open displacement） test data of 372 specimens tested in different temperatures, this paper discusses research work about fracture proof design that involves how to determine the criterion of CVN （Charpy V-notch） impact toughness by establishing the relationship between CTOD and CVN, how to prevent from brittle fracture by stress control in railway steel bridge design based on COD （crack open displacement） design curve through the test data and how to do the fatigue design for railway steel bridge at -50 ℃ of design temperature in an easy way. The method of fatigue design at -50 ℃ environment has been used for railway steel bridge structure of Qinghai-Tibet Railway in China.

Long-Term High-Temperature Oxidation of Alloys for Intermediate Heat Exchangers

Alloy 617 is the reference candidate material for high temperature components of gas-cooled reactors, like intermediate heat exchangers. Oxidation tests were performed with two heats of Alloy 617 up to 5000 hours at 950℃ under a simulated helium-cooled reactor environment. Post-treatment examination showed that all materials actually oxidized during the tests with the growth of a surface chromium oxide scale that includes titanium, formation of a carbide-depleted zone underneath the surface, and internal oxidation of aluminum. These oxidation-related phenomena are in good agreement with the data published in the 1980s for Alloy 617 in equivalent testing conditions and were used to assess the alloy corrosion performances. The oxidation kinetics was globally parabolic corresponding to the growth of the external oxide as well as to internal oxidation. In the given test environment, the parabolic rate constants are 0.00090 and 0.00058 mg^2·c^-4m·h^-1 for the two heats of Alloy 617.

Performance of U-tube Solar Water Heaters Facing Different Directions

System performance of solar water heaters depends upon collector and storage tank designs, solar radiation intensity and ambient temperature, amongst others. Evacuated glass tube collectors with U-tubes inside are less prone to leakages than the all-glass or the heat pipe types. U-tube solar water heaters suspended on walls and balconies could help overcome present day roof space restriction and increasing apartment-style housing. As such, their performance would depend upon its orientation when mounted in a vertical position. This paper reports the results of outdoor tests conducted on natural convection U-tube solar water heaters oriented towards different directions. Long and short term test procedures were employed to allow us to compare their performances as if they were tested simultaneously side-by-side.

Role of a Single Shield in Thermocouple Measurements in Hot Air Flow

To investigate the role of a single shield on steady temperature measurement using therrnocouples in hot air flow, a methodology for solving convection, conduction, and radiation in one single model is provided. In order to compare with the experimental results, a cylindrical computational domain is established, which is the same size with the hot calibration wind-tannel. In the computational domain, two kinds of thermocouples, the bare-bead and the single-shielded thermocouples, are simulated respectively. Surface temperature distribution and the tempera- ture measurement bias of the two typical thermocouples are compared. The simulation results indicate that： 1） The existence of the shield reduces bead surface heat flux and changes the direction of wires inner heat conduction in a colder surrounding; 2） The existence of the shield reduces the temperature measurement bias both by improving bead surface temperature and by reducing surface temperature gradient; 3） The shield effectively reduces the effect of the ambient temperature on the temperature measurement bias; 4） The shield effectively reduces the influence of airflow velocity on the temperature measurement bias.

Atmospheric Test and Numerical Models Assessment of Annular Combustor on ZK2000 Gas Turbine

ZK2000 is a newly developed 2 MW all radial gas turbine with an annular combustor. In this paper, the authors present the atmospheric test results of the combustor on test rig. Evaluation of several RANS turbulence models and reaction models were used in order to determine which model was the most appropriate combination for comparison with the test results. FGM with SST were selected because of the better agreement with test results in terms of combustor temperature rise, primary zone temperature, liner metal temperature, and NO_x emission predictions.