分布式能源联供技术在油田的应用

提出了适用于油田的天然气综合利用方案,开发了热电联供技术,介绍了热电联供装置的组成、选型原则以及在油田的实际应用方案和效果,提高了能源综合利用效率,降低了生产运营成本,适应油田电力和热能的需求,实现了"低碳环保、能效倍增"的生产目标。     

Environmental Effects on the Properties of Biopolymer Service-ware Products

The current trend towards sustainability has promoted a new interest in biodegradable plastics. Although there have been many studies on the behavior of biodegradable plastics, the changes in properties that may occur during use have not been fully documented. The mechanical properties of seven commercial service-ware items produced with biodegradable plastics were analyzed in this investigation. The effects of UV exposure, humidity, and accelerated aging on the mechanical properties were studied. In general, samples from polylactic acid and wheat straw had properties comparable to traditional synthetic plastics used in this application. However, the strength of other polymers such as bagasse, fiber pulp and potato starch was less than that of comparable synthetic plastics. The mechanical properties of the biopolymers generally deteriorated significantly upon exposure to UV radiation and humidity, with polylactic acid, wheatstraw, potato starch, and the bamboo bulrush wheatstraw blend being affected the most. Accelerated aging data indicate that after 6 months under ambient conditions, the potato starch, wheatstraw, and bamboo bulrush wheatstraw blend have a significant reduction in strength and modulus. In general, the thermal analysis behavior of most of the plastics was similar indicating a major weight loss of about 69–97% over a temperature range of 250–400?C. Additional improvements may be necessary to increase the environmental resistance of these biopolymers so that they can be effective replacements for traditional plastics.     

固体氧化物燃料电池系统及其应用

对固体氧化物燃料电池系统和单体电池及其工作原理、材料组成等作了简要介绍,并介绍了固体氧化物燃料电池在电厂混合发电方面与燃气轮机组成的联合系统技术以及以天然气为燃料家庭热电联产方面的应用。并指出固体氧化物燃料电池由于其高效、环保清洁将是未来能源利用的主要方式。     

Ethanol from corn: a technical and economical assessment based on different scenarios

A dry-grind ethanol from corn process analysis is performed. After defining a complete model of the process, a pinch technology analysis is carried out to optimise energy and water demands. The so-defined base case is then discussed in terms of production costs and process profitability. A detailed sensitivity analysis on the most important process and financial variables is carried out. The possibility to adopt different alternatives for heat and power generation combined to the process is evaluated.     

Reduction of Organic Emissions by Using a Multistage Drying System for Wood-Based Biomasses

Organic emissions during the thermal drying process are strongly dependent on the drying temperature. In the traditional single stage drying system, the inlet temperature of the drying air has to be relatively high in order to keep the airflow for drying small. In the multistage drying system, the drying airflow is heated up again after the first drying stage with higher moisture content, and then again after the second, and subsequent drying stages. In this method, the drying temperatures are limited in all stages to acceptable low levels, and only the moisture content of the drying air is increasing from one stage to another. As a result the multistage drying system has a lower drying temperature. We have studied the dependence of the organic emissions on the drying temperature, and present the results from drying units operating at temperatures of 100-200°C and below 100°C. The results are compared to previous measurements found in the literature. The estimates for the emissions at higher drying temperatures are derived from the literature values.     

热管技术在烟气余热利用上的应用研究

热电联供系统可以大幅度提高能源利用效率。针对集气站生产工况,采用热管式换热器回收燃气发电机高温烟气的余热,可以满足集气站对热能的需求。同时,热电联供系统以部分放空天然气为燃料,具有环保和节能双重效益。     

麦草碱-氧蒸煮脱木素

用碱－氧蒸煮麦草脱木素,考察了工艺条件对麦草脱木素的影响．结果表明：适宜的麦草脱木素的条件为温度 １６０℃,碱浓度 ８％,氧压 ０．８ ＭＰａ,固液比 ０．８,保温时间 １ｈ．同时,通过 ＩＲ和 １Ｈ－ＮＭＲ对木素结构进行了分析．     

热电联产方案选择的法律性文件

国家计委等四部委发布的《关于发展热电联产的若干规定》,第一次从法规上规范了发展热电联产的项目行为。这个文件,在相当长的一段时期内,将成为热力工作者进行热电联产、节能增效方案选择的指导性文件。     

Physical and frictional properties of non-treated and steam exploded barley, canola, oat and wheat straw grinds

During storage and handling, accurate knowledge of the physical and frictional behaviors of biomass grinds is essential for the efficient design of equipment. Therefore, experiments were performed on non-treated and steam exploded barley, canola, oat and wheat straw grinds to determine their coefficient of internal friction and cohesion at three hammer mill screen sizes of 6.4, 3.2 and 1.6 mm, three normal stress values of 9.8, 19.6 and 39.2 kPa at 10% moisture content (wb). At any specific hammer mill screen size, the geometric mean particle size and bulk density of non-treated straw was significantly larger than steam exploded straw. The bulk density of ground straw significantly increased with a decrease in hammer mill screen sizes. The steam exploded straw grinds resulted in higher coefficient of internal friction compared to non-treated straw grinds primarily because of lower bulk densities. The coefficient of friction for non-treated barley, canola, oat and wheat straw were in the range of 0.505 to 0.584, 0.661 to 0.665, 0.498 to 0.590, and 0.532 to 0.591, respectively. Similarly, the coefficient of friction for steam exploded barley, canola, oat and wheat straw were in the range of 0.562 to 0.738, 0.708 to 0.841, 0.660 to 0.860, and 0.616 to 1.036, respectively, which were higher than non-treated straw of the kind. Power, logarithmic or exponential equations were developed to predict the coefficient of internal friction and cohesion with respect to average geometric mean particle sizes for non-treated and steam explode barley, canola, oat and wheat straw grinds.     

SIMULTANEOUS DEVELOPMENT OF VELOCITY AND TEMPERATURE PROFILES IN THE ENTRANCE REGION OF A PARALLEL PLATE CHANNEL: LAMINAR FLOW WITH UNIFORM WALL HEAT FLUX

Available boundary layer type solutions to the combined hydrodynamic and thermal entrance region problem are known to exhibit a discontinuity in the gradients of the velocity and temperature distributions in the entrance region. A new solution is presented which alleviates this shortcoming. The new solution is based on the hydrodynamic inlet-filled region concept originally proposed by Ishizawa (1966) and later adopted by Mohanty and Das (1982) to hydrodynamically developing flow in a channel. This concept is extended to the combined entry length problem by dividing the thermal entrance length into two lengthwise regions, a thermal inlet region and a thermally filled region. In the former, the effect of heat transfer between fluid and wall is confined within the thermal boundary layer developing along the wall. At the end of the thermal inlet region, the thermal boundary layers meet at the duct axis but the temperature profile is not yet developed. In the thermally filled region, the heat effects propagate throughout the entire cross section and the temperature profile undergoes adjustment in a fully thermal region to finally attain the fully developed form. A thermal shape factor is also introduced in the thermally filled region which ensures that all thermal quantities attain their fully developed values asymptotically. The new model is used to obtain solutions to the combined entry length problem for laminar flow through a parallel plate channel under the constant wall heat flux boundary condition. The analysis gives considerably better results for the local Nusselt number and thermal entrance length than previously available.     

30年低温吹风气余热回收经验的结晶——记首套投运的带水冷壁的矮型次高压吹风气热电联产装置

按编制低温吹风气余热回收工程方案的有关思路,介绍了带水冷壁的矮型次高压吹风气热电联产装置的设计情况。该装置的建成投产,将低温吹风气余热集中回收技术推向了一个新水平。     

A novel method of utilizing the biomass resource: Rapid liquefaction of wheat straw and preparation of biodegradable polyurethane foam (PUF)

In the paper, wheat straw was rapidly liquefied in the mild condition. The optimum liquefaction effect was obtained at steam-explosion pre-treatment of wheat straw, liquefaction temperature of 140 °C, solvent/wheat straw ratio of 6:1, glycol (EG):glycerol = 5, sulfuric acid of 5%, and wheat straw of water content of 150%. During the liquefaction, cellulose, semi-cellulose and lignin are decomposed, which results in changes of hydroxyl value, acid value, viscosity and weight-average molecular weight of the reaction system. The liquefaction product was used to prepare polyurethane foam. Compared with the normal PUF, the foam had similar mechanical properties and better water absorption and biodegradability.     

碳铵法回收草浆造纸黑液中的碱

采用碳铵法对麦草造纸黑液进行碱回收,研究了工艺条件对碱回收的影响．结果表明：适宜的工艺条件为温度20℃,pH＝7,NH4HCO3浓度0．45mol／L,时间15min,搅拌速度100r／min,碱回收率可达78％．