燃料棒下端塞压塞机设计研究

压塞机是燃料棒进行电子束或非熔化极惰性气体钨极保护焊(TIG焊)接前将端塞压入包壳管中的一种重要设备。以往所使用的压塞机难以满足当前的使用需求。因此重新设计一种新型压塞机。通过对端塞结构及技术要求的分析,确定了压塞机设计思路。介绍了压塞机的端塞上料(储料)机构、送端塞机构、压塞机构、上下料机构及其附属机构设计理由和方法。在实际使用中,新设计的压塞机要求压塞过程安全、平稳、便捷、自动化,压塞后无划伤。

具有在线测量功能的三工位紧塞具压入机设计研究

分析目前使用的药筒紧塞具压入设备的缺点和不足,研究在线测量药筒实际装药高度的方法,提出在线测量药筒实际装药高度,同时根据装药高度控制紧塞具实际压入深度的设计思想,设计了一种具有在线测量功能的采用并行工作方式的三工位药筒紧塞具压入设备。该设备具有自动化程度高和能够精确控制紧塞具压入深度等特点。

PLC在全自动葡萄酒灌装压塞一体机上的应用

论述了可编程逻辑控制器(PLC)的概念、工作原理及在全自动葡萄酒灌装压塞一体机上的应用,指出PLC结构简单,功能强大,对设备主电机的运行速度和灌酒液位的控制更加精确,工作效率高,故障率低,且软件参数调整方便,可满足不同瓶型和不同工艺的生产需求。

全自动葡萄酒灌装压塞一体机上中PLC的应用分析

由于葡萄酒灌溉生产设备中对其控制装置要求较高，除了具备明显的灵活性外，还应具备简易的操作性能。因此本文就PLC应用于全自动葡萄酒灌装压塞一体机上进行分析，以此更好满足葡萄酒生产企业的需求。

让您轻松酿造优质葡萄酒及白酒

山东省诸城健源生物科技研究所是一家主要从事研制生产酒类酿造设备的科研单位,有各种规格的发酵罐、压榨机、过滤机、灌装机、压塞机、白兰地蒸馏器等各种设备,完全满足于小微酒庄自酿葡萄酒、白酒的需求。各种酿酒设备可一站式购齐,并根据用户酿酒规模量身定做;投资小利润高,免费传授各种酿酒技术并负责全程酿酒指导。目前除喝红酒保健外,国内酒类销售量最大的是白酒,投资白酒设备当年就有高利润回报。白酒越陈利润越高,特别是用各种水果(葡萄)蒸馏的白酒(白兰地)

Asymmetric vibration characteristics of two-cylinder four-stroke single-piston hydraulic free piston engine

The structure and working principle of a two-cylinder four-stroke single-piston hydraulic free piston engine(HFPE) were introduced. The basic vibration equation of free piston assembly(FPA) was established based upon the energy conversion between the injected fuel and the friction together with the load. Both the theoretical and numerical results show that the vibration system of FPA is a nonlinear conservative autonomous system in one cycle. The FPA vibration is symmetric with constant amplitude when FPA is only driven by the compression pressure in the compression accumulator and that in the combustion chamber. When considering the friction and load, FPA could still achieve a stable vibration after a few cycles' adjustment whether the input energy is equal to the consumed energy or not. The vibration characteristics are different when FPA vibrates in the compression stroke and the expansion stroke, which is the unique feature of the single-piston HFPE.

H2 Production from Wind Power in a Wind Farm in Spain

A hydrogen production and conversion plant from wind power was installed in the Sotavento wind farm by Gas Natural and the Galician Government. This facility is the highest electrolysis power installed at the European level. It consists of an electrolyser of 300 kW, a piston compressor, a 1,725 Nm3 H2 storage system and an engine of 55 kW. This pilot plant is being operated by Natural Gas in order to extrapolate its behavior to that of an industrial facility capable of managing all the production of Sotavento wind farm following different strategies： balancing, peak-shaving and repowering. In this paper, preliminary results at the facility are presented. The aim of these first tests has been to describe the operation of equipment under operating conditions required in the management of wind power production, in order to understand the behavior of the different equipment and try to make them suitable for this type of applications. This paper shows the difficulty of operating these systems under the wind power requirements.

Effects of rare-earth Y addition on microstructure and mechanical properties of lead-tin bronze

Piston pump rotor is one of the indispensable parts of hydraulic machinery,whose performance and quality determine the drive efficiency and service life of the piston pump.This paper mainly studies the effect of rare-earth yttrium(Y)on the microstructure and properties of the wear layer in piston pump rotor.The material of the wear layer is composed of lead-tin bronze.By adding different contents of rare earth Y,observe the change of microstructure and properties of lead-tin bronze.Through comparison,the addition of rare-earth Y can improve the tensile strength and elongation of lead-tin bronze,and the organization of lead particle morphology has become much smaller and uniformer than that without rare-earth.However,if the amount of rare-earth is too high,the tensile strength and elongation decrease,and the lead particles in the organization also have the tendency to grow up.Finally,it is concluded that when the amount of rare earth is 0.04%,the comprehensive performance is the best.

Simulation and Experimental Research on Fuel Spray Characteristics of a Self-pressurized Injector

As a miniaturized direct injection(DI)solution,a self-pressurized injector is of great significance for small aviation piston engines,such as spark-ignited two-stroke heavy-fuel engines.The spray characteristics of DI injectors are an important application prerequisite.In this paper,the computational fluid dynamics(CFD)software AVL Fire is employed to study the spray characteristics.Two types of spray models are established based on the Han Sheet model and the KH-RT model,and simulation works are carried out according to two types of spray tests in the literature.The comparison results show that in the constant volume bomb test,the spray patterns obtained by simulation under the two sets of environmental pressures are similar to those in the experiment,and the simulation spray using the KH-RT model can fit the spray contraction of the near nozzle field and the vortex of the far nozzle field better.In the tube test,the spray patterns obtained by simulation under the five sets of flow velocity are similar to those in the experiment,and the simulation spray using the KH-RT model can fit the spray expansion and the vortex of the far nozzle field better.The RP-3 kerosene spray characteristics of the self-pressurized injector are also experimentally studied,and the results demonstrate that due to the higher viscosity of kerosene,the spray shrinks more easily,resulting in a smaller spray cone angle and larger penetration.Therefore,changes in environmental pressure have greater impact on the kerosene spray pattern.

Reducing the Gas Pressure Drop in Suction Mufflers of Hermetic Reciprocating Compressors

The suction muffler of hermetic reciprocating compressors is installed in order to attenuate the noise generated by the gas pulsation of the flow through the suction valve. However, the installation of the suction muffler affects the operation of the compressor owing to gas pressure drop, which causes volumetric and energetic efficiency loss due to the gas specific volume augmentation. Therefore, there is a compromise between sound attenuation and pressure drop increase, which has to be taken into account by compressor designers. In this work, it presents a numerical solution to the flow through a suction muffler in order to analyze the pressure field and point out the main contributions to the overall pressure drop of the flow. A commercial CFD （computational fluid dynamics） code was used to perform the numerical simulations and the results were validated by using experimental data. After analyzing the pressure field, the geometry of the muffler was modified intending to decrease the flow pressure drop. The geometric modification produced a 28% reduction on the overall pressure drop, without influencing the sound attenuation.

Simulation of Reciprocating Compressor Start-up and Shut-down under Loaded and Unloaded Conditions

During the start-up and shut-down phase of reciprocating compressors, the loads on all components of driven train system are very high. In this paper a method for calculating the forces on coupling, e-motor, crank shaft as well other components of the system will be described. The modelling of the electrical induction motor, coupling, crank shaft, damper as well as the compressor resistance torque are extremely important in simulating start-up and shut-down of reciprocating compressor. Furthermore the switching torque of the electrical motor and the instantaneous moment of inertia of the reciprocating compressor crank gear are important as well. The transient start-up and shut-down process under loaded and unloaded conditions is described using a non-linear differential equation for driven train system： E-motor--coupling--flywheel--reciprocating compressor--damper. Shaft torsional moments on the drive train and especially on the coupling, whether elastic or stiff, can then only be calculated using numerical simulation. This paper will describe some of the key elements in modelling, simulating and measurements of drive train start-up and shut-down carried out on already operational piston compressor units.

Energy conversion characteristics of reciprocating piston quasi- isothermal compression systems using water sprays

Air compressors are vital and have numerous industrial applications. Approximately 8% of the annual operating electricity consumption in industrial countries is constituted by due to the use of air compressors. Because the poor heat transfer to the environment in the rapid compression process, the compression is non-isothermal, the efficiency of compressors is restricted. To improve their efficiency and achieve isothermal compression, this study proposes energy conversion reciprocating piston quasiisothermal compression using a water spray. First, a mathematical model of a reciprocating piston compressor with water sprays was established. Through experimental investigation and simulations, the mathematical model was validated. The energy conversion characteristics of the reciprocating piston compressor were then studied. To reduce compression power and enhance compression efficiency, it was first discovered that the critical parameters were the input pressure of the driving chamber, water spray mass, and compression volume ratio, which were then evaluated thoroughly. The higher the inlet pressure of the driving chamber, the faster the air compression velocity. Additionally, the compression efficiency was elevated as the water spray mass was gradually increased for a given compression volume ratio. When the compression volume ratio was increased from 2 to 3,the compression power increased from 172.7 J/stroke to 294.2 J/stroke and the compression efficiency was enhanced from 37.3%(adiabatic) to 80.6%. This research and its performance analysis can be referred to during the parameter design optimisation of reciprocating piston quasi-isothermal compression systems using water sprays.

Relationship between the Flow Blockage of Tip Leakage Vortex and its Evolutionary Procedures inside the Rotor Passage of a Subsonic Axial Compressor

The near casing flow fields inside the rotor passage of a 1.5 stage axial compressor with different blade-loading levels and tip gap sizes were measured by using stereoscopic particle image velocimetry(SPIV). Based on a carefully defined blockage extracting method, the variations of blockage parameter inside the blade passage were analyzed. It was found that the variation of blockage parameter appeared as a non-monotonic behavior inside the blade passage in most cases. This non-monotonic behavior became much more remarkable as the blade loading increases or mass flow rate decreases.The variations of the blockage parameter inside the blade passage had close relation to the evolutionary procedures of the tip leakage vortex(TLV). The destabilization of the TLV caused a rapid increasing of the blockage parameter. After the TLV lost the features of a concentrated streamwise vortex,the blockage parameter usually got a peak value. And then, because of the intense turbulent mixing between the TLV low momentum flow and its surrounding flows, the flow deficit inside the TLV recovered.

Early use of non-invasive positive pressure ventilation for acute exacerbations of chronic obstructive pulmonary disease:a multicentre randomized controlled trial

Background Respiratory muscle fatigue plays an important role in acute exacerbations of chronic obstructivepulmonary disease (AECOPD)·In previous clinical studies, non-invasive positive pressure ventilation (NPPV)was proved to be successful only for AECOPD patients with severe respiratory failure·We hypothesized that, theoutcomes of AECOPD would be improved if NPPVis early (within 24 to 48 hours of admission) administered inthose patients with respiratory muscle fatigue and mild respiratory insufficiency, especially in patients withoutfulfilling the conventional criteria of mechanical ventilatory support·Methods Aprospective multicentre randomized controlled trial was conducted in19 hospitals in China over16months·Three hundred and forty-two AECOPD patients with pH≥7·25 and PaCO2>45 mmHg were recruitedon general ward and randomly assigned to standard medical treatment (control group) or early administration ofadditional NPPV (NPPV group)·Results The characteristics of two groups on admission were similar·The number of AECOPD patientsrequiring intubations in NPPV group was much fewer than that of the control group (8/171 vs 26/71,P=0·002)·Subgroup analysis showed the needs for intubation in mildly (pH≥7·35) and severe (pH<7·30)acidotic patients in NPPVgroup were both decreased (9/80 vs2/71,P=0·047 and 8/30 vs3/43,P=0·048,respectively)·The mortality in hospital was reduced slightly by NPPV but with no significant difference (7/171vs 12/171,P=0·345)·Respiratory rate (RR),scale for accessory muscle use and arterial pHimproved rapidlyat the first 2 hours only in patients of NPPV group·After 24 hours, the differences of pH, PaO2, scale foraccessory muscle use and RR in NPPV group [(7·36±0·06) mmHg, (72±22) mmHg, (2·5±0·9) /min,(22±4) /min] were statistically significant compared with control group (7·37±0·05) mmHg, (85±34)mmHg, (2·3±1·1) /min, (21±4) /min,P<0·01 for all comparisons]·Conclusions The early use of NPPV on general ward improves arterial blood gas and respiratory pattern,decreases the rate of need for intubation in AECOPD patients·NPPV is indicative for alleviating respiratorymuscle fatigue and preventing respiratory failure from exacerbation·