热价值理论及其在加热炉节能中的应用

给出了预热助燃空(煤)气和热装时的热价值计算公式,比较加热炉的热工指标,指出热价值可以合理评价热能在加热炉中的有效利用状况.建立了炉内逆流换热模型,主要利用热价值理论研究了预热空(煤)气和热装对热价值的影响.结果表明:提高预热温度,热价值升高,且随着预热温度的进一步提高,热价值的增长率变小;热装可以使热价值升高,且热装温度越高,其热价值的增长率越大;设计时,当装料温度较高时应选择小的炉长,预热温度较高时应选择大的炉长.

铁水温度价值的分析和评价

提出了铁水温度价值和热价值的观点,对其进行了分析,提出了科学正确评估铁水质量和温度价值的方法。指出要进一步降低铁水单耗,要有技术上的投入和管理、政策上的支持。

价值方程推导及其在节能评价中的应用

热价值理论主要用于评价能量的有效利用程度.在该理论的基础上,结合热力学第二定律,推导出了依附于冷体、热体的价值方程.以加热炉钢坯热装和空(煤)气预热的算例为例,计算了两种情况下依附于钢坯和炉气的热价值和价值.结果表明,价值和热价值均随钢坯热装温度、空(煤)气预热温度的提高而提高;依附于炉气的价值在炉内传热良好且烟气入炉温度达到1 700 K甚至更高时高于其热价值,说明此条件下量得到了比热量更好的利用程度.

内蒙古中西部农牧民居住建筑冬季室内热舒适度

通过对内蒙古中西部农牧民居住建筑和生活情况实地调研,并对冬季室内温度和热舒适进行现场实测,统计分析得出:农牧民居住建筑冬季室内温度主要分布在10~16℃,温度普遍偏低,大多数农牧民感觉偏冷,这对保障农牧民的健康舒适,提升他们的生活品质还有一定差距。通过深入研究热感觉与室内温度、服装热阻、新陈代谢率及年龄之间的相互关系,得出内蒙古中西部农牧民居住建筑冬季室内可接受温度范围为13.63~21.66℃,期望温度为19.38℃,热中性温度为16.09℃。这一结论对深入研究农牧民居住建筑冬季室内热舒适度,为农牧民住宅冬季供暖温度提供依据及对提升农牧民生活品质具有重要意义。

A new method on hydrothermal scheduling optimization in electric power market

The hydrothermal scheduling in the electric power market becomes difficult because of introducing competition and considering sorts of constraints. An augmented Lagrangian approach is adopted to solve the problem,which adds to the standard Lagrangian function a quadratic penalty term without changing its dual property,and reduces the oscillation in iterations. According to the theory of large system coordination and decomposition,the problem is divided into hydro sub-problem and thermal sub-problem,which are coordinated by updating the Lagrangian multipliers,then the optimal solution is obtained. Our results for a test system show that the augmented Lagrangian approach can make the problem converge into the optimal solution quickly.

A novel model for cost performance evaluation of pulverized coal injected into blast furnace based on effective calorific value

The combustion process of pulverized coal injected into blast furnace involves a lot of physical and chemical reactions. Based on the combustion behaviors of pulverized coal, the conception of coal effective calorific value representing the actual thermal energy provided for blast furnace was proposed. A cost performance evaluation model of coal injection was built up for the optimal selection of various kinds of coal based on effective calorific value. The model contains two indicators: coal effective calorific value which has eight sub-indicators and coal injection cost which includes four sub-indicators. In addition, the calculation principle and application of cost performance evaluation model in a Chinese large-scale iron and steel company were comprehensively introduced. The evaluation results finally confirm that this novel model is of great significance to the optimal selection of blast furnace pulverized coal.

Potential of Benja Geothermal Springs for Direct Utilization

In the Benja of Permeti village, eight springs are located in the Lengarica creek, and their curative values are known and used since the time of the Roman Empire. The eight springs erupt mineral water with temperatures in the range of 23-30℃ and yields in the range of 8 up to more than 40 L/s. The geothermal fluid, even though with relatively low temperatures, represent a competitive energy resource. The geothermal water flows directly to the river of Langarica, similarly with the other geothermal resources of Albania can be ＂translated＂ as ＂throwing in the creek＂ of considerable monetary values, delay in the economic development, infrastructure and also negative social impacts in the region. This paper aims to show that these waters are a competitive energy resource by the implementation of a combined and cascade system, and also they can by efficiently used for greenhouses, aquaculture and salts extraction.

Numerical and experimental evaluation on methods for parameter identification of thermal response tests

Several parameter identification methods of thermal response test were evaluated through numerical and experimental study.A three-dimensional finite-volume numerical model was established under the assumption that the soil thermal conductivity had been known in the simulation of thermal response test.The thermal response curve was firstly obtained through numerical calculation.Then,the accuracy of the numerical model was verified with measured data obtained through a thermal response test.Based on the numerical and experimental thermal response curves,the thermal conductivity of the soil was calculated by different parameter identification methods.The calculated results were compared with the assumed value and then the accuracy of these methods was evaluated.Furthermore,the effects of test time,variable data quality,borehole radius,initial ground temperature,and heat injection rate were analyzed.The results show that the method based on cylinder-source model has a low precision and the identified thermal conductivity decreases with an increase in borehole radius.For parameter estimation,the measuring accuracy of the initial temperature of the deep ground soil has greater effect on identified thermal conductivity.

Caloric Restriction and Litter Size Do Not Compromise Renal Function of Male Wistar Rats

This work had the purpose of comparing some renal parameters of Wistar rats raised in small litters either freely-fed （G3L） or subjected to 30% caloric restriction （G3R） with those of rats from normal litters （Gg） at the age of 90 days. The results showed that the relative weight of the kidneys and urinary flow were not significantly different. All the groups had GFR （glomerular filtration rate） and proteinuria within normal values, despite group G3R having values statistically lower. However, group G3R had diminished glomerular area and increased numbers of renal corpuscles. Group G3L did not exhibit differences compared with controls （G9）. The effects of caloric restriction did not compromise kidney structure and function in 90-day-old rats.

Effect of heat flux and inlet temperature on the fouling characteristics of nanoparticles

In order to study the effect of heat flux and inlet temperature on the fouling characteristics of nanoparticles, and to further reveal the fouling mechanism for insights into proper operating conditions, γ-Al_2O_3/water suspensions were chosen as the subject of this research. The particulate fouling characteristics of γ-Al_2O_3/water suspensions on the surface of stainless steel have been experimentally studied by varying the heat flux and the inlet temperature under single-phase flow and subcooled-flow boiling conditions. The results show that in the condition of single-phase flow, the asymptotic value of fouling resistance decreases with increasing of heat flux and inlet temperature. The asymptotic value of fouling resistance under single-phase flow is much higher than for the subcooled-flow boiling condition. The effect of heat flux on the fouling resistance under the two flow states has an inverse relationship, and there exists a minimum value of fouling resistance between these two states. For subcooled-flow boiling, the asymptotic value of fouling resistance increases with increasing heat flux, whereas the effect on fouling resistance by the inlet temperature is negligible.

Conceptual Framework for an Integrated Method to Optimize Sustainability of Engineering Systems

It is necessary to change the current dynamic of growth, to assure that future generations can satisfy their needs. Sustainable development and global sustainability are two concepts that have achieved great importance in almost every sector of activity. There is a wide range of methods and models for sustainability assessment. Nevertheless, it is necessary to go beyond evaluation, looking for sustainability optimization. In spite of this, little work has been done on the latter field. The authors present here a conceptual proposal for an integrated method to optimize sustainability of engineering systems, based on the MIVES （integrated value method for evaluating sustainability） method. For a better understanding of the method, its essential steps for optimizing an energy sub-system are summarized （shell-and-tube heat exchanger）.

Effect of Chia Seed on Physicochemical and Sensory Characteristics of Common Carp Restructured as Functional Food

Physicochemical and sensory characteristics of restructured meat of common carp （Cyprinus carpio） fortified with 0-8 g/100 g of chia seed flour （CSF） was evaluated. It had a higher nutritional value （higher fibre content and protein retention] （p 〈 0.05） and better cooking characteristics （higher cooking yield and moisture retention） （p 〈 0.05） than the control. The colour （a＊, b＊） increased; lightness and whiteness index decrease （p 〈 0.05）. Hardness increase （p 〈 0.05） occurred because of CSF addition. Differential scanning calorimetry showed that fibre fortification did not interfere with the thermal transitions of the restructured meat. No significant differences were detected with the preference test scores of 4% or 8% CSF compared with the control. Restructured （4%-8% CSF） had a higher content of fibre and fat, which could be linoleic and linolenic acid, and an increase in the content of protein compared with those of commercial products, among had 1.62 and 2.25 mg AGE/g. Therefore, the restructured properties of common carp were governed by CSF addition.

2CaO-SiO_2固相反应温升的研究

利用气–固反应中的Luss界面反应扩散控制模型模拟研究了2CaO–SiO2固相反应自放热引起的温升,探讨了提高放热效应热价值的最佳工艺条件。研究表明:在同等条件下换热热阻对固相反应热引起的温升影响最大,窑中不同换热条件下固相反应温升相差10倍以上,生料粒度对固相反应温升影响较小,粒径为80μm和10μm的颗粒温升差别仅为4倍。