14. starptautiskÄ konference 2012 - Latvijas JÅ«ras akadÄmija

More documents

Recommendations

Info

Proceedings of 14th International conference „Maritime Transport and Infrastructure - 2012”same time the importance of analysis of cargo volumes (annual throughput) transshipped by the portand changes in commodity mix are stressed. The analysis revealed that over the last 10 years thediametrically opposed processes took place in the ports of Riga and Ventspils. If at the former theconcentration of cargo assortment occurred, at the latter the structure of cargo became morediversified. The structure of cargo turnover at small ports became more balanced in 2010 compared to2000. However, timber still accounted for two thirds of total turnover. The results of the analysis ofstructure dissimilarity for cargo turnover at Latvia’s ports demonstrated that it was much moresignificant during the period from 2000 to 2005 than from 2005 to 2010. According to Szalay indexthe structure of cargo transported though Latvia’s ports underwent the most important changes atVentspils port. Nevertheless, Gatev coefficients pointed at the most considerable transformation atRiga port. According to the coefficient of determination R 2 the equations for loaded cargoes at Latvia’sports (with exception of Ventspils port) demonstrated better goodness of fit compared to the ones forunloaded cargo.References1. A. V. Vasiliauskas, I. Kabashkin. Comparative analysis of the actions towards sustainable transport systemdevelopment in Latvia and Lithuania. Proceedings of the 6th international scientific conference “Transbaltica”,2009. – pp. 237-241.2. A. Maciulis, A. V. Vasiliauskas, G. Jakubauskas. The impact of transport on the competitiveness ofnational economy. 2009. Available (accessed on 15.03.2012):http://www.thefreelibrary.com/The+impact+of+transport+on+the+competitiveness+of+national...-a02274615823. I. Kabashkin. Logistics centres development in Latvia. Transport. – Vol. 22, No. 4, 2007. – pp. 241-246.4. E. Meirane. Research on the structure of cargo flow in Latvia. Transport. – Vol. 22, No. 3, 2007. – pp. 195-199.5. A. Michaelowa, K. Krause. International Maritime Transport and Climate Policy. Intereconomics. - Vol. 35,No. 3, 2000. – pp. 127-136.6. D. W. Song. Regional container port competition and co-operation: the case of Hong Kong and South China.Journal of Transport Geography. – Vol. 10, 2002. – pp. 99-110.7. M. Benacchio, C. Ferrari, H. Haralambides, E. Musso. On the economic impact of ports: local vs. nationalcosts and benefits. Special Interest Group on Maritime Transport and Ports. International Workshop. - Genoa,June 8-10, 2000. Available (accessed on 15.03.2012):http://www.informare.it/news/forum/2000/sig2/genovaes.asp8. G. R. Yochum, V. B. Agarwal. Economic impact of a port on a regional economy. Growth and Change. –Vol. 18, No. 3, 1987. - pp. 74-87.9. G. R. Yochum, V. B. Agarwal. Static and changing port economic impact. Maritime Policy andManagement. - Vol. 15, No. 2, 1988. – pp. 157-171.10. J. DeSalvo. Measuring the direct impacts of a port. Transportation Journal. - Vol. 33, No. 4, 1994. – pp. 33-42.11. J. DeSalvo, D. Fuller. The role of price elasticities of demand in the economic impact of a port. Review ofRegional Studies. – Vol. 25, No. 1, 1995. – pp. 13-35.12. R. O. Goss. Economic policies and seaports. The economic functions of ports. Maritime Policy andManagement. - Vol. 17, No. 3, 1990. – pp. 207-219.13. P. Gripaios. Ports and their influence on local economies - a UK perspective. The Dock & HarbourAuthority. - Vol. 79 (894), 1999. – pp. 235-241.14. P. Gripaios, R. Gripaios. The impact of a port on its local economy: the case of Plymouth. Maritime Policyand Management. - Vol. 22, No. 1, 1995. – pp. 13-23.15. R. Gailītis, M. Jansen. Development of the Latvian maritime policy – a maritime cluster approach.Proceedings of 12 international conference “Maritime Transport and Infrastructure – 2010”. – Rīga: LatvijasJūras akadēmija, 2010. – pp. 15-21.16. E. Kasalis, I. Kasalis, J. Kasalis. Clusters approach as one of determinants for increasing competitivenessof freeport Riga. Proceedings of 13 international conference “Maritime Transport and Infrastructure – 2011”. –Rīga: Latvijas Jūras akadēmija, 2011. - pp. 46-51.17. Практикум по социальной статистике (под ред. И. И. Елисеевой). – Москва: Финансы и статистика,2002. - 368 стр.18. Encyclopaedia of Measurement and Statistics (ed. by L. J. Salkind). Vol. 1. – London: Sage Publications,2007. – 424 p.19. J. Stewart. Assessing alternative dissimilarity indexes for comparing activity profiles. Electronicinternational Journal of Time Use Research. - Vol. 3., No. 1, 2006. – pp. 49–59.24
Proceedings of 14th International conference „Maritime Transport and Infrastructure - 2012”TECHNICAL DIAGNOSTICS OF THE SHIP ELECTRIC COMPRESSORINSTALLATIONS ON THE BASIS OF MATHEMATICAL MODELAleksandrs Gasparjans*, Aleksandrs Terebkovs*, Anastasia Zhiravetska***Latvian Maritime Academy, 5B Flotes st, LV-1016, Latvia, E-mail: Aleksandrs.Gasparjans@latja.lv,aleksandrs.terebkovs@latja.lv.**Riga Technical University,14 Azenes st, LV-1048, Latvia. E-mail: zhiravecka@eef.rtu.lvAbstractThe system of technical diagnostics of double-stage electric compressor installation is described. Themodel is mathematically proved together with the block diagram of the measurement elements.KEY WORDS: compressor, induction motor, mathematical model, diagnosticsIntroductionThe obtaining of high pressures in single-stage compressors causes difficulties due to severalreasons:1. gas in a compressor is compressed according to polytrope law with the index of polytropen>1. The temperature of the compressed gas significantly exceeds the initial. Under this condition itcan achieve the temperature of cylinder oil flash, i.e. resulting in "diesel" effect;2. at high temperatures the process of cylinder oil oxidation is significantly accelerated;3. increasing of the ratio of initial pressure to its final value P 0 /P 2 results in decreasing of thecompressor effectiveness factor. For improvement of the effectiveness it is necessary to enlarge thesizes of the stage. This will result in the increasing of the mechanical and dynamic loads as well ascompressor sizes and weight;4. with the increasing of the ratio P 0 /P 2 the value of volume factor of the compressor stage isdecreasing. Thus all the compressed gas can be located in the volume of the died space and theexhaust valve will not open.1. Differential double-stage compressorFig. 1 demonstrates a differential double-stage compressor. Pistons of the first stage (lowpressure) 11 and high pressure 12 are one whole element. Air with its initial pressure Р 0 is inhaustedthrough filter 1 and through inhaust valve 2 of the first stage is proceeding to the cylinder space of thelow pressure. While piston 11 goes up the compressed air is extruded through the exhaust valve 3 tothe pathway of the average pressure Р 1 . This pathway is equipped with protective valve 5, sensor ofinstant pressure 6, refrigerator 7, moisture oil separator 8. Cooled and cleaned air of average pressureР 1 goes to the high pressure cylinder through exhaust valve 9. The compression of gas in the highpressure cylinder takes place due to the down movement of valve 11, 12. Relatively to thecompressing period in the cylinder of low pressure the compressing period in the second stage isshifted for 180 0 rotation angle of the crankshaft. It allows aligning of the torques on the shaft of thecompressor. The compressed gas of high pressure through the exhaust valve of the second stage 10and refrigerator 13 goes to moisture oil separator 16 and further to receiver 17 and then to consumers.The pathway of the high pressure has protective valve 14 and sensor of instant pressure 15. Theflywheel of the compressor has sign of top dead centre (TDC) with sensor of TDC 18. For defining theangular velocity and angular acceleration of the crankshaft the uniformly placed magnetic signs 20 andsensor of angular velocity 19 are used. The compressor is driven by means of three-phase inductionmotor 21.25
Page 1 and 2: LATVIJAS JŪRAS AKADĒMIJALJA PĒTN
Page 3: Proceedings of 14th International c
Page 7 and 8: Proceedings of 14th International c
Page 21 and 22: 20002001200220032004200520062007200
Page 51 and 52: KEMPINSKItNt>...... /1--":-...... I
Page 71 and 72: Concentration, mg/m 3Proceedings of
Page 73 and 74: 0:001:002:003:004:005:006:007:008:0
Page 75 and 76:
Proceedings of 14th International c
Page 77 and 78:
Page 79 and 80:
Page 81 and 82:
Page 83 and 84:
Page 85 and 86:
Page 87 and 88:
Page 89 and 90:
Page 91 and 92:
Page 93 and 94:
Page 95 and 96:
Page 97 and 98:
Page 99 and 100:
Page 101 and 102:
Page 103 and 104:
Page 105 and 106:
Page 107 and 108:
Page 109 and 110:
Page 111 and 112:
Page 113 and 114:
Page 115 and 116:
Page 117 and 118:
Page 119 and 120:
Page 121 and 122:
Page 123 and 124:
Air temperature, deg CWater tempera
Page 125 and 126:
Water level (+/-), centimetreProcee
Page 127 and 128:
Page 129 and 130:
Page 131 and 132:
Page 133 and 134:
Page 135 and 136:
Page 137 and 138:
Page 139 and 140:
Page 141 and 142:
Mln. LtMln. LtProceedings of 14th I
Page 143 and 144:
Page 145 and 146:
Page 147 and 148:
Page 149 and 150:
Page 151 and 152:
show all

14. starptautiskÄ konference 2012 - Latvijas JÅ«ras akadÄmija

You also want an ePaper? Increase the reach of your titles

Delete template?

Save as template?

14. starptautiskÄ konference 2012 - Latvijas JÅ«ras akadÄmija