高效有机助磨剂

将掺合或不掺合有机助磨剂的锆英砂装入普通湿法球磨机中进行研磨,并将磨细的粉料混入卫生陶瓷轴料中烧成,对比测试结果显示,有机助磨剂的加入不仅大幅提高研磨效率,降低锆英砂粉料的最终细度,还能提高轴面白度。     

A theoretical study on a novel combined power and ejector refrigeration cycle

A new combined power and refrigeration cycle is proposed for the cogeneration, which combines the Rankine cycle and the ejector refrigeration cycle by adding an extraction turbine between heat recovery vapor generator (HRVG) and ejector. This combined cycle could produce both power output and refrigeration output simultaneously, and could be driven by the flue gas from gas turbine or engine, solar energy, geothermal energy and industrial waste heats. Parametric analysis and exergy analysis are conducted to examine the effects of thermodynamic parameters on the performance and exergy destruction in each component for the combined cycle. The results show that the condenser temperature, the evaporator temperature, the turbine inlet pressure, the turbine extraction pressure and extraction ratio have significant effects on the turbine power output, refrigeration output, exergy efficiency and exergy destruction in each component in the combined cycle. It is also shown that the biggest exergy destruction occurs in the heat recovery vapor generator, followed by the ejector and turbine.     

Numerical assessment of steam ejector efficiencies using CFD

Ejector efficiencies for the primary nozzle, suction, mixing and diffuser were determined for the first time, according to their definitions, using an axi-symmetric CFD model. Water was considered as working fluid and the operating conditions were selected in a range that would be suitable for an air-conditioner powered by solar thermal energy. Ejector performance was estimated for different nozzle throat to constant section area ratios. The results indicated the existence of an optimal ratio, depending on operating conditions. Ejector efficiencies were calculated for different operating conditions. It was found that while nozzle efficiency can be considered as constant, the efficiencies related to the suction, mixing and diffuser sections of the ejector depend on operating conditions.     

Performance analysis of a supersonic ejector cycle working with R245fa

A supersonic ejector chiller for industrial use is currently being developed and tested as part of a project cooperation between Frigel s.p.a and DIEF (Department of Industrial Engineering, University of Florence). The refrigerator was built following a “ready to market” setup criterion and is intended for applications on the industrial refrigeration market or in air conditioning. The plant has a nominal cooling power of 40 kW and is powered by low temperature heat (from 90 up to 100 °C). The ejector is equipped with a movable primary nozzle and 9 static pressure probes along the mixing chamber/diffuser duct. The working fluid is R245fa. An extensive numerical campaign was performed to analyze the internal dynamics of the ejector. All the simulations were carried out by accounting for the real gas properties of the refrigerant. Comparison with experimental data resulted in close agreement both in terms of global and local parameters. Analyses showed that in order to achieve an accurate matching with the experimental data, it is necessary to correctly account for the surface roughness of the ejector. This is especially true for off-design operating conditions.     

Ejector in R410A vapor compression systems with experimental quantification of two major mechanisms of performance improvement: Work recovery and liquid feeding

This paper presents experimental data and analysis comparing the performance of an R410A ejector vapor compression system to those of a liquid-fed evaporator system and a conventional expansion valve system. The objective was to quantify separately two major improvements of the ejector system: work recovery and liquid-fed evaporator. The ejector system was first compared to a system with liquid-fed evaporator at matching cooling capacities and revealed improvements from 1.9% to 8.4% solely due to the work recovery of the ejector. When compared to a conventional expansion valve system at the same cooling capacity, the ejector setup improved COP from 8.2% to 14.8% due to simultaneous benefits of liquid-fed evaporator and work recovery. Overall ejector efficiencies from 12.2% to 19.2% were achieved.     

气体引射器型红外抑制器的结构及性能研究

通过介绍红外抑制器的工作原理，用实验和数值方法分析了由不同的抑制器结构引起的不同红外抑制效果。通过对多组参数的数值计算和实验测量，得出了有关结构参数对红外抑制装置工作性能的影响规律，为以后抑制器的设计提出了最佳的组合方案和取值范围。实验结果表明，装置有较好的红外抑制效果。     

改善DF喷吸钻排屑性能的措施

分析了喷吸钻喷吸原理，提出了改善排屑性能的措施。     

Application of an ejector in autocascade refrigeration cycle for the performance improvement

This paper presented a novel autocascade refrigeration cycle (NARC) with an ejector. In the NARC, the ejector is used to recover some available work to increase the compressor suction pressure. The NARC enables the compressor to operate at lower pressure ratio, which in turn improves the cycle performance. Theoretical computation model based on the constant pressure-mixing model for the ejector is used to perform a thermodynamic cycle analysis for the NARC with the refrigerant mixture of R23/R134a. The effects of some main parameters on cycle performance were investigated. The results show the NARC has an outstanding merit in decreasing the pressure ratio of compressor as well as increasing the COP. For NARC operated at the condenser outlet temperature of 40 °C, the evaporator inlet temperature of −40.3 °C, and the mass fraction of R23 is 0.15, the pressure ratio of the ejector reaches to 1.35, the pressure ratio of compressor is reduced by 25.8% and the COP is improved by 19.1% over the conventional autocascade refrigeration cycle.     

Fuel ejector design and simulation model for anodic recirculation SOFC system

In this paper, a new modeling technique for fuel ejectors with high entrainment ratio, low pressure increment and over heated working gases in an anodic recirculation solid oxide fuel cell (SOFC) system is presented. By utilizing the thermodynamic, fluid dynamic principles and chemical constraints inside ejectors and employing a two-dimensional function to compute fluid velocity, the developed model involves no more than nine algebraic equations and this is very simple compared to all existing models. The detailed procedures for fuel ejector design and simulation are provided and its effectiveness is verified through simulation and compared with testing results. It shows that the proposed model is more accurate than presently available models, and therefore can be better used for ejector design and performance simulations. The ejector performances for both situations of stand-alone and integrated into the SOFC system are also studied.     

推卸铲运机在采矿新方法中的应用

推卸铲运机是一种新式铲运机。在丰山铜矿分段碎石胶结充填采矿法中,我国首次成功应用了自行研制的推卸铲运机,取得了很好的生产效果。本文就推卸铲运机解决的主要技术难题以及结构特点、工作原理等作了论述。