基于单片机与PLC的温度控制装置的应用

印染厂印染、煮练工艺的升温控制是影响产品质量的关键所在。从工艺机理出发 ,通过对其升温工艺的研究 ,运用单片机、可编程序控制器的有效组合 ,引入模糊控制方式实现了此过程温度自动控制。文章简单介绍了其温度自动控制装置的构成和研究。

硫基离子液体电解质拓宽量子点敏化太阳能电池的应用温度范围(英文)

制备了1-甲基-3-丙基咪唑硫离子液体电解质,并应用在量子点敏化太阳能电池中。通过优化S和Na2S的浓度,电解质的电导率在25°C下达到了12.96 m S?cm^(-1)。差示扫描量热法分析表明离子液体电解质的玻璃化转变温度为-85°C。采用该电解质的量子点敏化太阳能电池在25°C下达到了3.03%的光电转化效率(η),与采用水基电解质的电池的效率3.34%接近。由于本文中的离子液体电解质具有低玻璃化转变温度和不易挥发的优点,采用离子液体电解质的量子点敏化太阳能电池在-20°C(η=2.32%)及80°C(η=1.90%)的温度下表现出了比水基电解质优异的光电转化性能。

单片机在高精度温度测量系统的应用

由于一般测温系统中测温元件自身的精度问题,以及普通系统中信号在线路上的衰减和漂移,使得一般的温度测量系统很难满足高精度的要求,在某些需要对较小温度变化(如0.1℃)作出反应的场合,难以用于指导工业生产。针对这一情况,本文提出了一种以16位单片机80C196KC为基础的新型高精度温差测量系统,并对系统实现方法和原理进行了详细的阐述。

铂电阻温度计在成品油公路付油系统中的应用

针对成品油油库公路付油过程中因油品温度变化引起的油品体积变化,从而影响实际付油精度的问题,提出在付油管路中流量计前加装高精度铂电阻温度计与温度传感器连接,即时采集付出油品的实时温度,通过逻辑分析判断,引用车用汽、柴油各自油品膨胀系数或内嵌《石油计量表》(GB1885),实时计算并修正自动付油程序中的付油量,可提高付油精度。四座油库运行的数据表明,付油准确度保持在0.1%以内,大大低于容积式流量计本身0.2%的准确度等级。

温度传感器在医学领域的应用研究

阐述了各种温度传感器的工作原理,归纳和总结了各种传感器的特点及其在医学领域的应用,对其在医学领域应用前景进行了展望。

可控硅在位式调节仪表调温中的应用

应用位式调节仪表(如动圈式仪表、自动平衡记录仪等)进行温度调节H寸,一般都通过交流接触器进行,但该接触器通断时振动大,调节不够理想。因此近年来位式调节仪也有通过可控硅进行调节的。该方法具有振动小、无噪声、不产生电弧和反映灵敏等优点。应用于位式调节的可控硅线路因调节品质要求都不很高,在导通相位上不要求准确触发,这就可以大大简化触发线路。从电源获取触发信号是较理想的简易方法,具有无复杂脉冲线路,触发可靠和元件少等特点。下面介绍几种典型的线路。一、半波可控硅调压线路图1为该线路示意图。

Application of Microcalorimetric Technique for the Screening and Examination of Medicines

According to the heating effect caused by interaction between matters,a series of experiments on the interaction between drugs and cells from human bodies,DNA and physiological saline have been carried out with a MS-80 standard Calvet microcalorimeter.The experiments include: (1) Thermokinetic studies of the effect of anticancer drugs [sodium norcantharidate (ASN),the bioac- tire materials (Sp.P and Sp.S) from algae etc.]on the cancer cells [Hela,human breast carcinoma (Bcap-37),human adenocarcinoma gastric cells (SGc-7901 and MCF-7) etc.] and the normal cells from human bodies [diploid fibroblasts from human fetal lung (2BS) etc.] at 310.15 K:(2) Studies of the in- tercalation binding of some alkaloidal drugs with the bioactivity to inhibit monoamine oxidase (harmalinc and harmine etc.) to call thymus DNA in neutral aqueous solution at 298.15 K:(3) Studies of the interaction between long acting drugs (long acting oral contraceptive-norgestrel etc.) and slow- releasing drug (Contac) and aqueous solution of 0.9% NaCI at 310.15 K.All the experimental results have given their characteristic thermograms and the interaction enthalpy changes.On the analysis of all the results,the authors put forward a method on application of microcalorimetric technique for screen- ing and examination of medicines.The principle of application and the experimental operation of this method have been expounded,and some results of the above experiments have been discussed.As one of the methods for screening and examining medicines,the microcalorimctric method has some distin- guished features and advantages over other methods.

脉波轮廓温度稀释连续心排量测量技术在心脏直视术后的临床监测及应用

目的探讨脉波轮廓温度稀释连续心排量测量技术(PICCO)在心脏直视术后患者血流动力学参数监测中的应用及效果。方法 2011年1月-2012年6月采用PICCO监测20例术后危重患者的心功能指数(CI),全心舒张末期容积指数(GEDI),血管外肺血指数(ELWI),对监测结果为CI<3 L/(min·m2)、GEDI<700 mL/m2、ELWI>10 mL/kg的患者,治疗上慎重增加容量,同时增加儿茶酚胺类药物剂量的对策;对CI<3L/(min·m2)、GEDI>700 mL/m2、ELWI>10 mL/kg的患者,治疗上予以增加儿茶酚胺类药物剂量同时严格控制容量,每日严格泵入液体量及管喂量的处置方式;对CI>3 L/(min·m2)、GEDI<700 mL/m2、ELWI>10 mL/kg、SVRI<900 kPa·s/(min·m2)的患者,则采取容量增加慎重同时增加儿茶酚胺类药物剂量,调节去甲肾上腺素用量的方式。结果经PICCO严密监测以及药物和容量调整,19例患者循环逐渐稳定,均拔除气管插管后转出重症监护室(ICU)回病房继续治疗,1例因全心功能衰竭,抢救无效死亡。结论通过应用PICCO对心脏直视术后患者血流动力学参数进行监测,能更直观有效、及时精确的找准血流动力学不稳定因素,对症下药,改善患者心功能情况,减少ICU住院天数,提高患者治愈率。

Oxidative Desulfurization of Non-hydrotreated Kerosene Using Hydrogen Peroxide and Acetic Acid

The oxidative desulfurization of a real refinery feedstock (i.e.,non-hydrotreated kerosene with total sulfur mass content of 0.16%) with a mixture of hydrogen peroxide and acetic acid was studied.The influences of various operating parameters including reaction temperature (T),acid to sulfur molar ratio (nacid/nS),and oxidant to sulfur molar ratio (nO/nS) on the sulfur removal of kerosene were investigated.The results revealed that an increase in the reaction temperature (T) and nacid/nS enhances the sulfur removal.Moreover,there is an optimum nO/nS related to the reaction temperature and the best sulfur removal could be obtained at nO/nS=8 and 23 for the reaction temperatures of 25 and 60°C,respectively.The maximum observed sulfur removal in the present oxidative desulfurization system was 83.3%.

Application of Choline Chloride·xZnCl2 Ionic Liquids for Preparation of Biodiesel

The inexpensive and moisture-stable Lewis-acidic ionic liquids were prepared and applied for transesterification of soybean oil to biodiesel.The influences of molar ratio of methanol to soybean oil,reaction temperature and amount of ionic liquids were investigated.The transesterification of soybean oil to biodiesel catalyzed by choline chloride·xZnCl2 ionic liquids showed many advantages such as mild conditions and lower cost.On the other hand,the non-ideal yield and complicated separation between biodiesel and soybean oil were also investigated and analyzed.The improvement on the systems of choline chloride·xZnCl2 was proposed for further investigation.

Application of PID Controller Based on BP Neural Network in Export Steam’s Temperature Control System

By combining the Back-Propagation （BP） neural network with conventional proportional Integral Derivative （PID） controller, a new temperature control strategy of the export steam in supercritical electric power plant is put forward. This scheme can effectively overcome the large time delay, inertia of the export steam and the influencee of object in varying operational parameters. Thus excellent control quality is obtaitud. The present paper describes the development and application of neural network based controller to control the temperature of the boiler＇s export steam. Through simulation in various situations, it validates that the control quality of this control system is apparently superior to the conventional PID control system.

Effects of thermal treatment on physical and mechanical characteristics of coal rock

To study the physical and mechanical properties of coal rock after treatment at different temperatures under impact loading, dynamic compression experiments were conducted by using a split Hopkinson pressure bar(SHPB). The stress–strain curves of specimens under impact loading were obtained, and then four indexes affected by temperature were analyzed in the experiment: the longitudinal wave velocity, elastic modulus, peak stress and peak strain. Among these indexes, the elastic modulus was utilized to express the specimens' damage characteristics. The results show that the stress–strain curves under impact loading lack the stage of micro-fissure closure and the slope of the elastic deformation stage is higher than that under static loading. Due to the dynamic loading effect, the peak stress increases while peak strain decreases. The dynamic mechanical properties of coal rock show obvious temperature effects. The longitudinal wave velocity, elastic modulus and peak stress all decrease to different extents with increasing temperature, while the peak strain increases continuously. During the whole heating process, the thermal damage value continues to increase linearly, which indicates that the internal structure of coal rock is gradually damaged by high temperature.

Control and application of cooling path after rolling for hot strip based on ultra fast cooling

Hot rolled strip requires diverse and flexible control of cooling path in order to take full advantages of strengthening mechanisms such as fine grain strengthening, precipitation strengthening, and transformation strengthening, adapting to the development of advanced steel materials and the requirement of reduction-manufacturing. Ultra fast cooling can achieve a great range of cooling rate, which provides the means that the hardened austenite obtained in high temperature region can keep at different dynamic transformation temperatures. Meanwhile, through the rational allocation of the UFC （ultra fast cooling） and LFC （laminar flow cooling）, more flexible cooling path control and cooling strategy of hot rolled strip are obtained. Temperature distribution and control strategies under different cooling paths based on UFC are investigated. The process control temperature can be limited within 18 ℃, and the mechanical properties of the steels get a great leap forward due to the cooling paths and strategies, which can decrease costs and create great economic benefits for the iron and steel enterprises.

Research on application of different particle sizes of cordierite on castable refractory

Effect of different particle sizes of cordierite on properties of castable refractory by different heat treatment temperatures were investigated respectively with mullite and bauxite as raw materials, calcium aluminate cement as binders. After 24 h curing in mould and another 24 h curing at 110 ℃ after demoulding, the specimens were heat treated at 1 000 ℃, 1 300℃ and 1 500℃ for 3 h, respectively. The bulk density （ BD）, permanent linear change （ PLC）, modulus of rupture（MOR） and clod crushing strength（CCS）, thermal expansion coefficient and thermal shock resistance were examined. The results show that there is no obvious effect on adjusting permanent linear change and bulk density of castables by adding different particle sizes of cordierite at low temperature and intermediate temperature. Modulus of rupture of castable increase with the decreasing of the particle sizes of cordierite after heat treated by 1 000 ℃ and 1 300℃. In this experiment, thermal shock resistance of the castable with cordierite whose particle size is 0 - 1 mm is the best.

Tensile properties of as-deformed 2A50 aluminum alloy in semi-solid state

Tensile properties of as-deformed 2A50 aluminum alloy were investigated in the high temperature solid and semi-solid states. The results show that temperature has almost no effect on the maximum tensile stress between 500 ℃ and 530 ℃, and the maximum tensile stress decreases rapidly when the temperature is above 532 ℃. The ductility decreases with increasing temperature and has an obvious fall when the temperature is above solidus temperature. This alloy almost has no ductility above 537 ℃, and cannot sustain tensile stress above 550℃. A brittle temperature range in which this alloy is prone to form microcracks was derived. The relation between microstructure, fraction solid and tensile properties were also investigated by examining the metallograph and fracture surface morphology of tested specimens, which could provide reference for forecasting the microcracks in this alloy occurring in semi-solid processing.

Application of Supercritical CO2 Gas Turbine for the Fossil Fired Thermal Plant

A supercritical CO2 gas turbine cycle can produce power at high efficiency and the gas turbine is compact compared with the steam turbine. Therefore, it is very advantageous power cycle for the medium temperature range less than 650 ℃. The purpose of this paper is to show how it can be effectively applied not only to the nuclear power but also to the fossil fired power plant. A design of 300 MWe plant has been carried out, where thermal energy of flue gas leaving a CO2 heater is utilized effectively by means of economizer and a high cycle thermal efficiency of 43.4 % has been achieved. Since the temperature and the pressure difference of the CO2 heater are very high, the structural design becomes very difficult. It is revealed that this problem can be effectively solved by introducing a double expansion turbine cycle. The component designs of the CO2 heater, the economizer, supercritical CO2 turbines, compressors and the recuperators are given and it is shown that these components have good performances and compact sizes.

Study on Activated Bentonite Applied to tert-Butylation of Toluene

tert-Butylation of toluene with tert-butanol used as the alkylating agent was investigated over the activated bentonite and HY zeolite used as the catalyst.The influences of various butylation reaction parameters,including the toluene/tert-butanol ratio,the reaction temperature,and the space velocity were discussed.The optimal results were obtained at a reaction temperature of 180 ℃,a space velocity of 4 h-1,and a mole ratio of toluene to tert-butanol equating to 2.The structure and acidic properties of catalyst were characterized by the BET method and the Fourier transform infrared (FTIR) spectroscopy.Compared with the HY zeolite,the activated bentonite possessed high activity for toluene conversion and high para-selectivity because it had larger pore diameter,smaller micropore surface area and higher ratio of total Lewis acids to total Br nsted acids.

Application of fiber Bragg grating sensor network in aluminum reduction tank shell temperature monitoring

A fiber Bragg grating temperature sensor network was designed to implement the real-time health monitoring of the aluminum reduction cell. The heat transfer process was simulated using software ANSYS, and an on-line shell monitoring system was established based on optical sensing technology. According to aluminum reduction cell heat transfer theory, the 2D slice finite element model was developed. The relationship between shell temperature and cell status was discussed. Fiber Bragg grating （FBG） was chosen as the temperature sensor in light of its unique advantages. The accuracy of designed FBG temperature sensors exceeds 2 ~C, and good repeatability was exhibited. An interrogation system with 104 sensors based on VPG （volume phase grating） filter was established. Through the long-term monitoring on running state, the status of the aluminum reduction cell, including security and fatigue life could be acquired and estimated exactly. The obtained results provide the foundation for the production status monitoring and fault diagnosis. Long-term test results show good stability and repeatability which are compatible with electrolysis process.

Application of Fuzzy Control to Improve Flow Balance of Multi-Cavity Hot Runner System

In this study, we propose a new temperature compensation control strategy for a multi-cavity hot runner injection molding system, At first, the melt filling time of each cavity can be measured by installing temperature sensors on the position around end filling area, and filling time difference between the various cavities can be calculated. Then the melt temperature of each hot nozzle can be adjusted automatically by a control strategy established based on the Fuzzy Theory and a program compiled with LABVIEW software. Temperature changes the melt mobility, so the adjustment of temperature can equalize the filling time of the melt in each cavity, which can reduced the mass deviation between each cavity and make product properties of each cavity consistent. The conclusion of the experiment is as follows： For this contact lens box of a four-cavity Hot Runner mold, by applying hot runner temperature compensation control system, time difference can be reduced from 0.05 s to 0.01 s at each cavity, and the mass Standard deviation of the four cavity can be improved from 0.006 to 0.002. The ratio of imbalance can be reduced from 20% to 4%. Hence, the hot runner temperature compensation control system has significant feasibility and high potential in improving melt flow balance of multi-cavity molding application.