模糊免疫自适应PID控制在封水泵流量控制中的应用

为提高封水泵流量控制的智能化、稳定性和高效性,在分析封水泵工作原理的基础上,设计一种基于西门子的可编程逻辑控制器(Programmable Logic Controller,PLC)的模糊免疫自适应比例积分微分(Proportion Integration Differentiation,PID)控制器.利用MATLAB对控制器仿真,结果表明该控制器具有较好的快速性、鲁棒性和稳定性,实际控制效果良好.     

延长高危潜油电泵井检泵周期方法的探讨

南堡油田某采油区电泵井总井数30口,其中电缆绝缘值低或者无绝缘的风险井18口,占电泵总井数的60%.为了防止这些高危电泵井躺井影响产量,针对这些高危电泵井加强了精细化管理,结合油井实际的生产状况,及时分析电流、压力、液面、泵工况、清蜡、加药等现场资料,摸索制定出高危潜油电泵井的现场管理方法,延长了油井的检泵周期.     

灰色关联度在模拟废水源热泵热水器性能中的应用

根据废水源热泵热水器与外界能量交换的特点,依照热力学原理和试验结果确定了影响其性能的潜在因素,采用灰色关联分析方法,确定了各性能参数的主要影响因素．在此基础上,确定了构建经验数学模型的策略,获得了废水源热泵热水器主要性能指标,如制热性能系数COP、制热量瓯、热水产量（流量）“。和压缩机耗功Ⅳ等的经验数学模型．结果表明,灰色关联分析可以快速准确地分析出主要影响因素,为构建经验模型提供基础．     

Arrangement strategy of ground heat exchanger with groundwater

The orientation strategy of side pipe and the heat transfer performance of six ground heat exchangers(GHEs) were optimized by numerical simulation,with soil being treated as a porous medium.An experiment on the heat transfer of four GHEs was carried out in 2010.Results indicate that the velocity field is disturbed by GHEs.The optimal orientation strategy of side pipe is that the upward pipe is located upstream and the downward pipe downstream.The space between GHEs should be appropriately adjusted,depending on the direction and flow velocity.Groups of GHEs should be installed perpendicular to the mainstream in a single row,but if the acreage does not meet the requirements,GHEs should be installed in staggered multiple rows.Fewer GHEs parallel to the mainstream strengthen the heat transfer.Moreover,numerical results agree well with the test data,with the maximum relative error being less than 7.7%.     

Theoretical Study on CO_2 Transcritical Cycle Combined Ejector Cycle Refrigeration System

Mechanicalvapourcompressioncyclesaremainlyemployedinmostrefrigerationsystems .Chlorofluoro carbons(CFCs)orhydrochlorofluorocarbons(HCFCs)aregenerallyusedasrefrigerantsinthesesystemsdrivenbyelectricityfromburningfossilfuels ,whichresultsino zonedepletionduetotheleakageandpoorrecoveryofthoseman maderefrigerants,andglobalwarmingowingtoCO2 emissionfrom powerstationsandthereasonisthatCFCsorHCFCsarepowerfulgreenhousegases.Inaddition,otherenvironmentalissuesarealsocausedbytheNOx,SO2 andpartic…     

梯度折射率双包层光纤激光器的吸收效率

1IntroductionSingle mode,rare earth(RE)doped fiber lasers oramplifiers have found wide applications that requirecompact,rugged optical source.They are recognizedas an efficient configuration to generate light of singletransverse mode,but generally regarde…     

浅谈工程建设中泵送混凝土的应用

由于泵送混凝土在现代建筑工程中广泛应用,本文从泵送混凝土原材料、配合比设计、混凝土的供应以及混凝土泵送与浇筑四个方面对泵送混凝土的要求作了阐述。     

烟气(水蒸气)混注喷射泵结构设计

本文提出了将蒸汽喷射泵应用于蒸汽—烟道气混注的新思路.蒸汽喷射泵注汽锅炉产生的高压水蒸气为动力,可以为伴随注汽锅炉产生的烟道气提供足够的能量,使其与水蒸气充分发生混合,并将混合后的气体注入油井.依据工程热力学基本理论与喷射泵工作的基本原理,对蒸汽喷射泵用于稠油井注烟道气进行了可行性研究和论证;并且设计计算得到了喷射泵的工作参数     

土壤源热泵技术分析

通过论述土壤源热泵技术的工作原理、系统组成、特点。并详细分析了其主要部件地热换热器的埋管方式、结构、管材、运行等特点，在此基础上提出了一种地热换热器的传热模型及其传热模拟试验方法，为进一步研究土壤源热泵技术打下了基础，同时指出土壤源热泵技术是一种前景非常广阔的制冷空调技术，应该大力提倡推广使用这种技术。     

A 1.2-to-1.4 GHz low-jitter frequency synthesizer for GPS application

A fully integrated frequency synthesizer with low jitter and low power consumption in 0.18 μm CMOS (complementary metal-oxide semiconductor) technology is proposed in this paper.The frequency synthesizer uses a novel single-end gain-boosting charge pump, a differential coupled voltage controlled oscillator (VCO) and a dynamic logic phase/frequency detecor (PFD) to acquire low output jitter.The output frequency range of the frequency synthesizer is up to 1 200 MHz to 1 400 MHz for GPS (global position system) application.The post simulation results show that the phase noise of VCO is only 127.1 dBc/Hz at a 1 MHz offset and the Vp-p jitter of the frequency synthesizer output clock is 13.65 ps.The power consumption of the frequency synthesizer not including the divider is 4.8 mW for 1.8 V supply and it occupies a 0.8 mm×0.7 mm chip area.