带回热循环的闭路式热泵干燥装置

介绍一种具有回热循环的闭路式热泵干燥装置,其除湿率高,能量利用率高,且封闭循环,是较理想的节能型环保型干燥装置。     

太阳能食物干燥床

每逢夏季农村社员很需要干燥多余的蔬菜和瓜果等。一九八○年苏联研制成功一种太阳能食物干燥床。该装置结构简单,经久耐用,造价不高(比现有太阳能干燥装置便     

节能环保型热泵干燥装置

介绍一种具有回热循环的闭路式热泵干燥装置,其除效率高,能量利用率高,且封闭循环,是较理想的节能,环保型干燥装置。     

羽绒流化床干燥装置及其控制系统的研制与应用

针对我国的羽绒干燥设备结构复杂、能耗高、效率低和产品含水率高等问题,研制开发了羽绒流化床干燥装置及其控制系统,在国内首次采用流化床作为羽绒干燥装置,并配套开发了计算机监控系统,采用高可靠性工业控制计算机和先进的模糊控制策略进行工作过程的实时监控,实际应用表明,本装置具有显著的经济效益和推广应用价值。     

热泵干燥装置的技术经济及环境分析

热泵干燥具有节能、低温干燥及环境友好等优点,但与普通干燥装置相比,有初投资大等不足。本文以中小型热泵干燥装置为背景,对热泵干燥装置与普通干燥装置在采用电能、煤、天然气为能源时的技术、经济、环境特性进行了对比分析,为热泵干燥装置的应用提供了直接的参考。     

水循环式热泵干燥装置的分析

热泵干燥装置具有节约能源、环境友好、可低温干燥等特点。水循环式热泵干燥装置是指热泵和干燥部分通过水循环耦合而成的热泵干燥装置,与热泵和干燥部分直接耦合相比,具有不向环境排放热量、机组调控性好、对干燥过程的匹配性好、成本低等优势,是一种较适宜于中小型热泵干燥装置的结构型式。     

羽绒流化床干燥装置及其控制系统的研制与应用

针对我国的羽绒干燥设备结构复杂、能耗高、效率低和产品含水率高等问题,在国内首次采用流化床作为羽绒干燥装置,并配套开发了计算机监控系统。实际应用表明,本装置能实现安全可靠连续干燥过程,可使能耗降低10%～20%,生产效率提高8%～15%,干燥后的羽绒含湿量由原来的10%下降到3%～5%,具有显著的经济效益和推广应用价值。     

余热回收式热泵干燥装置的设计与分析

为提高热泵干燥装置的节能效率,设计并研制了能够对干燥室排出的高温气体进行余热回收的热泵干燥装置,并对其进行了性能测试。采用可编程控制器对热风的温度、湿度和风速进行调节,并可对干燥室排出的废热进行回收利用。利用该热泵干燥装置对香菇进行的干燥实验表明:该热泵出风口温度可达65℃,干燥室内温度分布均匀;与电加热干燥装置相比,该装置的干燥时间可缩短5~7 h,每度电的处理量提高了2.3倍,并且提高了干燥品质。     

压缩空气站的节能设计

本文对压缩空气站设计中喷油螺杆式空气压缩机吸气位置不当导致的吸气温度高、空压机排气量下降从而造成能源浪费进行了定量分析并提出了节能的措施 ;论述了压缩空气站设计中很少注意到的露点对能耗的影响和正确确定压缩空气露点的方法 ;对常用的无热再生压缩空气干燥装置、冷冻干燥装置的技术性能和使用效果进行了分析 ;在此基础上 ,着重对无热再生压缩空气干燥装置和无热再生复合干燥装置的能量消耗进行了定量分析对比。在综合分析和论证的基础上 ,提出了在设计压缩空气站时应当着力关注的节能设计意见。     

热泵干燥装置的节能研究

对热泵干燥装置混合工质进行优选,建立典型热泵干燥装置结构数学模型,研究提出目标函数并开发出适合热泵干燥结构的程序算法。     

Optimization of ethanol production from high dry matter liquefied dry sweet sorghum stalks

The ability of sweet sorghum to be utilized as feedstock for ethanol production at high initial dry material concentration was investigated. Sweet sorghum, after being dried, was liquefacted employing commercial cellulase solution Celluclast^® 1.5L, in order submerged fermentation to be permitted under high-solids concentrations. The presence of a separate enzymatic liquefaction step at 350 kg m⁻³ initial DM enhanced both ethanol production and productivity by 29.76% and 250%, respectively. Response surface methodology, based on the central composite design was applied to explore the combined effect of liquefaction duration and enzyme loading in order liquefaction conditions to be optimized. When the optimum conditions were tested using an enzyme load of 8.32 FPU g⁻¹ of dry material for 8.6 h at 50 °C, high productivity (3.0 kg m⁻³ h⁻¹) and final ethanol production (62.5 kg m⁻³) were achieved.     

Microwave-assisted dry reforming of methane

The microwave-assisted dry reforming of methane over an activated carbon, which acted as catalyst and microwave receptor, was investigated. As a preliminary study, the CO₂ reforming of CH₄ was carried out using conventional heating and microwave heating in order to compare both heating devices. Higher conversions of CH₄ and CO₂ were achieved by microwave heating. Under microwave heating, various operating variables were studied in order to determine the best conditions for performing dry reforming with high conversions and the most suitable H₂/CO ratio. Thus, the dry reforming reaction was studied at different temperatures. An optimum range of working temperatures (between 700 °C and 800 °C) was established. In this range of temperatures, the dry reforming reaction is believed to take place as a combination of CH₄ decomposition and CO₂ gasification. Carbonaceous deposits from CH₄ decomposition are gasified by CO₂ and, as a result, active centres for the dry reforming reaction are constantly regenerated. The effect of the proportion of CO₂ fed in on the CH₄ and CO₂ conversions was also investigated. Small increases in the percentage of CO₂ fed in gave rise to large increases in both conversions, but especially in the case of CH₄. The volumetric hourly space velocity was also studied. It was found that the lower the space velocity, the higher the conversions obtained.     

Progress in hot dry rock exploitation

The term hot dry rock (HDR) has been used to describe the exploitation of the thermal energy contained in rocks that have a sufficiently high temperature but contain insufficient fluids to enable the heat to be extracted. The attraction of such a resource is that it is probably available everywhere, but at varying depths. International activity has focused on the problem of circulating fluids through the rock and extracting the heat by conduction from the rock to the fluid. The initial concepts were based on creating individual cracks to interlink two wells approximately 500 m apart. The necessary heat exchange area was to be achieved by using multiple systems of interconnections in parallel. The results from the field work have shown that the interlinking is dominated by stimulated natural joints and the degree of normal dilation that can be achieved is limited by the orientation of the natural discontinuity with the pre-existing stresses and, hence, the shear stress on the joint. The normal dilation is important because it controls the resistance to flow between the wells. The shear mechanism controls the far-field water losses and the direction of growth of the more permeable interwell region and has obvious implications for the proposed geometry of any system. The cost of drilling has been shown to be comparable to deep drilling for other purposes and the development of deviated holes in strong crystalline rocks has been shown to be possible. The progress of the stimulation has been mapped successfully by locating the microseismic events generated by shearing but the relationship of the microseismically active areas and the heat transfer region has yet to be identified. No adverse environmental problems have been identified; the produced fluids are generally benign and the microseismicity is well below any threshold of damage. The goal of a universally available heat source free of stack emissions and waste products that does not consume finite reserves of minerals and hydrocarbon demands substantial investment in the research to determine if it is attainable. The major field programmes should have reached their preliminary conclusions by the middle of 1986.     

厌氧干发酵技术研究进展

厌氧干发酵技术正逐渐成为世界各国处理有机同体废弃物以及生产新能源的重要选择.文章综述了厌氧干发酵机制以及厌氧干发酵工艺在发酵底物的选取、预处理、接种、发酵过程管理等方面的研究进展,总结了该技术在基础研究和实际应用中存在的一些问题,展望了其发展前景.     

Solar radiation model for hot dry arid climates

The industrialised countries have well-established solar radiation networks based on detailed observations of solar irradiance data from relatively sophisticated weather stations. However, in many regions of the developing countries the only available data consist of records of sunshine hours. There have been several approaches towards establishing a relationship between sunshine hours and solar irradiance. This paper describes how one particular formula, the Barbaro et al. model, has been modified to determine solar irradiance from sunshine hours for a number of stations located in hot dry arid climates.     

Extraction of heat from multiple-fractured dry hot rock

A brief summary of theoretical solutions for the extraction of heat from multiple-fractured dry hot rock is presented. The analysis is based on an infinite series of parallel vertical fractures of uniform aperture and separated by blocks of homogeneous and isotropic impermeable rock with a uniform spacing between fractures. Cold water enters at the bottom of the fractures and the solutions are given in terms of dimensionless parameters from which the exiting water temperature at the top of the fractures can be determined. An example of the application of the theory is given to demonstrate how a multiple, fractured system provides a more efficient mechanism for heat extraction than a single fracture in dry hot rock.     

农业废弃物干法厌氧发酵技术的研究

文章介绍了以农业废弃物为原料的干法厌氧发酵工艺的试验结果.当发酵温度为(35±1)℃,TS含量为20%,原料滞留期为60d时,平均池容产气率为2 l/(L·d),甲烷含量为65%以上.     

Thermodynamic and electrical properties of dry combustion plasma

Calculations of the thermodynamic and electrical properties of dry combustion plasma (DCP) produced by seeded combustion of a typical charcoal CSC, show that its adiabatic flame temperature and electrical conductivity are remarkably higher than those of conventional plasmas from fossil fuels hitherto employed in experimental MHD generators. Both these properties are strongly dependent on the concentration of H_xO_y species in the plasma. The results have been compared with data on the conventional plasmas. © 1998 John Wiley & Sons, Ltd.     

Maximum tolerable reservoir impedances for hot dry rock

The finite hydraulic impedance of the natural and artificial fractures that constitute the water flow paths in hot dry rock reservoirs is shown to influence the cost of generating electricity from such resources in two ways. First, pumps, and hence power, will be required to circulate water through the fracture system. Second, the pressure difference across the reservoir cannot be increased indefinitely to improve the energy extraction rate as too high a pressure at the injection borehole will cause unacceptable losses of the circulating water.