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influence of the shuga on waterways is almost gone now (become with a not high ofprobability).But the problems which is connected with the ice influence on the damgates were retained. If construction of water power plants is calculated with an iceloadings, so in this case the gates must be protected from the ice pressure. During thistime were elaborated and installed the methods for the holding of polynya infront of thegates. The basic methods now which are using for the holding of polynya by thebarbotage structures infront of the gates with using of air which is going from the sill ofthe gate along the pressure face, or holding of polynya by the stream-forming structureswhich give the jet of water along the pressure frontage. Determined all conditions forusing of this methods. Also was determined that this methods are effective with thepresence of the temperature stratification infront of the gates.Another very seriously problem of exploitation of the hydraulic engineering structuresand their equipment during winter period was the serving of possibility of the waterdropping in winter period. Usually it connected with regulation possibilities ofreservoirs with providing of work of the water power plant cascade in case if on one ofthe water power plants the working equipment was out of work , as in case of repairwork of the broken equipment or if equipment was stopped with necessity for thepassing of water according to sanitary or other reasons. In the most cases the passing ofthe flood realize with the high enough temperature of air outside of winter period.For providing of winter exploitation of water power plants we need the heating of theslot constructions and protection of pressure face of the gates from underwater icecovering. For the solving of this problems we have enough of home and foreignexperience in this field. Methodic for the heating of the slot constructions just the samelike for the gratings: direct electric power, inductive electric heating, oil heating orother. Now we have the problem with reconstruction of the heating systems which wereout of work. In this field we have brand new elaborates which were created in theB.E.Vedeneev All-Russia Research Institute of Hydraulic Engineering. This newelaborates were created on the base of using the silicon organic elements. Their usingfor reconstruction of the heating systems which was out of work made this problemmuch easy because now we do not need the expensive repair works which in the mostcases connected with replacement of the different parts of construction. This newelaborates made the completely new situation for using of the modern methods inoptimization of electricity discharges for the heating process by installation automaticcontrol systems with a program supply which is operate depends from our decision.Today we can say that exploitation of the hydraulic engineering structures in winterperiod connected with technical solutions which we can choice depends from conditionsand different tasks of exploitation. Very important to develop methods for prognosis ofexploitation conditions: hydrometeorological and technological.Prognosis of hydrometeorological factors is a very difficult problem. For the solving ifthis problem not enough to have a list of the statistic observations. Manifestation of thehydrometeorological factors depends not just from the complete set of construction andtechnical solutions but from the exploitation regimes in the most cases.During winter exploitation of the hydraulic engineering structures we must to use theactive ways in struggle with different negative influences. Very important to usedifferent ways in control of the negative influences on the first step of projecting of thehydraulic engineering structures with using of all exploitation experience in this fieldand most which was used in winter period.334
17th International Symposium on IceSaint Petersburg, Russia, 21-25 June 2004International Association of Hydraulic Engineering and ResearchENSURING OF OPERATION OF WITHDRAWALSIN FRAZIL-ICE CONDITIONSI.N.Shatalina, 1 G.A.Tregub 1 , N.S.Bakanovichus 1ABSTRACTOn the rivers with a long period of ice flow, difficulties in water collecting can occur.The purpose of this paper is working out hydraulic ways of withdrawal strainer protectionagainst frazil and avoiding supercooling effect inside the system. This paper concernsdifficulties arising in the operation of river withdrawals situated in the frazil producingriver stretches. Methods of calculations of frazil flow parameters are given. Theconstruction of water strainers of umbrella-like type and system of collector well heatingon the basis of compositional resistive materials (CRM) ensuring safe operation ofwithdrawals in frazil-ice conditions are proposed. The results of experimental analysisof the new strainer construction and the parameters of the new heating system of thewater collector well are represented.METHOD OF ESTIMATION OF WATER SUPERCOOLING AND FRAZILDISCHARGE COMING INTO WITHDRAWALSOn the large rivers like the Neva and the Amur the period of autumn frazil flow cancontinue rather long, sometimes up to more than a month. In the period of frazil flowand the beginning of freezing-up there are plenty of polynyas – ‘factories of frazil’. Atthis time withdrawals can have ice difficulties connected with blocking of the strainerwindows with passing frazil and their freezing in supercooled water. The method of estimationof water supercooling and frazil discharge coming into water collectors isbased on the Pekhovich model (Pekhovich, 1983). According to this model a fewstretches along the river can be described, every of which has a definite number of icethermal parameters: 1) the stretch of water supercooling to the section of inside waterice formation; 2) the stretch going from this section to the section of frazil flowing up;3) the stretch of growing supercooling to the section of maximum supercooling ; 4) thestretch of supercooling decrease to the section of maximum intensification of inside waterice formation; 5) the stretch to the ice edge. The mentioned stretches are separatedfrom each other with distinct sections and have the definite water temperature t , its gra-1The B.E. Vedeneev All-Russian Institute of Hydraulic Engineering (VNIIG), Gzhatskaya str., 21,St.Petersburg, Russia.335
Page 1 and 2: 17th International Symposium on Ice
Page 3 and 4: 57.00056.000Elevation (m)55.00054.0
Page 5 and 6: (m 3 /s)50004000300020001000Hour 24
Page 7 and 8: Tailwater Elevation vs. DischargeOb
Page 9 and 10: REFERENCESBerger, R.C. and Stocksti
Page 11: consequences of the blocked up turb
Page 15 and 16: The position of the section of maxi
Page 17 and 18: The purpose of the tests was to def
Page 19 and 20: size of the flowing up particle is
Page 21 and 22: The combined usage of the umbrella-
Page 23 and 24: hτιj⎡∂(hu∂ ⎤i ) (hu j )=
Page 25 and 26: length was ≈800 m, its average wi
Page 27 and 28: Fig. 5. The ice thickness distribut
Page 31 and 32: the most appropriate automatic spil
Page 33 and 34: HPP turbines were not operating dur
Page 35 and 36: shown (Figure 4). Along the front c
Page 39 and 40: constant inclination. The channel s
Page 41 and 42: All temperatures are compared with
Page 43 and 44: Differance [ o C]5.004.003.002.001.
Page 47 and 48: Fig. 2. Grounded hummock by drying
Page 49 and 50: from each board, going from stem to
Page 51 and 52: consist in indemnification of the i
Page 53: REFERENCE1. Goldshtejn R.V., Osipen

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