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1.
1.  For the first time in Russia a submersible axial-flow dredge pump was developed and tested for installation as a first-stage pump on dredges to reduce the negative pressure before the hold dredge pump and to increase its positive suction head.
2.  The use of the axial-flow dredge pump permits increasing the output of the dredge and depth of excavating the underwater borrow pit. With respect to power consumption the axial-flow pipe is 2–3 times more economical than ejection.
3.  The small mass of the pump permits mounting it on existing dredges without their alteration.
4.  Development and perfection of this direction is quite prospective for hydraulicking.
Translated from Gidrotekhnicheskoe Stroitel'stvo, No. 10, pp. 14–17, October, 1995.  相似文献   

2.
Conclusions  
1.  The circumferential distribution of static pressures in pump and turbine modes of operations was obtained experimentally for slot and labyrinth types of radial seals of a mixed-flow pump-turbine runner.
2.  In the optimal turbine mode the main frequency of pressure fluctuations in the seal is the blade frequency and in the optimal pump mode the blade and revolution frequencies.
Translated from Gidrotekhnicheskoe Stroitel'stvo, No. 2, pp. 23–24, February, 1997  相似文献   

3.
1.  Oscillations due to low-frequency sources of excitation beneath the impeller in the draft tube develop in long pipelines of water-storage power plants.
2.  For the Zagorsk water-storage power plant with a long (790 m) and flexible pipeline, the natural frequency of the first type of the system's oscillation is many times lower than the predominant frequency of the lowest-frequency component of the spectrum of pressure fluctuations beneath the impeller (0.24–0.25)fre. For a shorter and stiffer pipeline, the system would approach resonance.
3.  The dynamic properties of the system depend on the opening of the guide apparatus: for small openings, the natural frequency approaches f1=(C/4)L; with large openings, it approaches f2=(C/2)L.
4.  When the unit is operating in the stationary mode, the hydrodynamic loads on the pipe lining do not exceed 0.05 MPa; this corresponds to an additional stress of 0.07 MPa in the lining and vibrational displacements of 0.183 mm (when C=780 m/sec), i.e., not more than 0.06 of the radius of the pipeline; when C=965 m/sec, the vibrational displacements do not exceed 0.08 mm.
5.  The loads on the pipeline supports do not exceed 0.36 tons on any one pile.
Translated from Gidrotekhnicheskoe Stroitel'stvo, No. 8, pp. 27–30, August, 1992.  相似文献   

4.
Conclusions  
1.  Theoretical investigations and bench tests on a pump model made it possible to obtain the setting geometry that ensures extremely good power characteristics for pumps having large setting flow areas.
2.  It is recommended to use wear-resistant white chromium-manganese cast iron for components in the setting of the GrT-4000/71 soil pump, which is intended for the transfer of sandy-gravelly soils with a lump size no greater than 60 mm.
3.  Use of a dual-cup rubber shaft seal is recommended to improve the operational reliability of the pump.
4.  To extend the longevity and improve the reliability of the drive of the soil pump, it is proposed to use a bearing with a set of spring that lower the axial forces on the bearing.
Translated from Gidrotekhnicheskoe Stroitel'stvo, No. 2, pp. 31–37, February, 1999.  相似文献   

5.
1.  More than a decade of operation of water-cleaning machines with a conical net has demonstrated their good technical and economic characteristics as regards failure-free operation and water-cleaning performance.
2.  After a simple modification, the existing water-cleaning machines with a vertical axis of cone rotation can perform a fish-protecting function.
3.  For larger water consumers (such as water supply systems of thermal and nuclear power plants) machines with a horizontal cone rotation axis are recommended (so-called directflow water-cleaning machines). With some modernization of the flowthrough component, water offtake facilities can ensure bypass and survival of over 90% of young fish without building any expensive fish guard structures.
4.  Instead of fish guard facilities planned to be built at operating thermal and nuclear power plants, one should consider the possibility of removing the existing water-cleaning machines with flat nets and installing machines with conical nets.
Translated from Gidrotekhnicheskoe Stroitel'stvo, No. 12, pp. 37–40, December, 1990.  相似文献   

6.
1.  Modified wood is an effective substitute of the laminated wood lining of bearing bushings for vertical pump units.
2.  An investigation of modified wood showed that this material in some indices (friction coefficient and wear resistance) is better than laminated wood.
3.  Since there is no mass manufacture and centralized supply of modified wood, it is possible to create a technological department for its production.
4.  Organization of the department does not require capital expenditures and special accommodations.
5.  Machining of the wood is performed on ordinary metal-cutting machines with the use of the tools used when machining laminated woods.
Translated from Gidrotekhnicheskoe Stroitel'stvo, No. 7, pp. 33–35, July, 1991.  相似文献   

7.
1.  The energy-storage hydroelectric station (ESHES) can provide a 1.5–2-fold increase in peak capacity with a simultaneous threefold decrease in daily fluctuations of the water level in the lower pool.
2.  A decrease in the length of the concrete structures located in the river channel (especially the length) of the powerhouse) reduces the consumption of concrete for the ESHES in comparison with the HES, which compensates for the cost of constructing the additional structures of the ESHES.
3.  Unlike the HES, the ESHES operates in a sharp-peak regime and also during passage of flood waters.
4.  Contrarotating pump-turbines are best suited for an ESHES because of various combinations of heads on its turbine and pump parts.
5.  With increase in the speed of multistage hydraulic machines their placement depth decreases and the cost of the powerhouse is reduced.
  相似文献   

8.
Conclusions  
1.  The design organization could not have contemplated the scale of the loosening of the rock mass, as a result of which the lower surface of the dam and the contact zone of the foundation bed were not instrumented to the degree necessary for direct measurments of openings and loosening in the contact zone.
2.  The readings of available slit gages are insufficient for estimation of total openings.
3.  Lower and upper estimates of the openings in the contact zone near the thrust face are obtained from readings of transverse hydrolevels. It is understood from geometric representations that even for several horizons, the total opening cannot exceed the vertical component of the displacements obtained as a result of inclination of the lower surface.
4.  In addition to estimates of maximum expected openings, the fact of the “in-leakage” of these values from year to year is of interest. Estimating this process for the period from 1991 through 1997 from hydrolevel readings, we obtain an additional opening of from 2.3 to 4.4 mm in section 33 (according to minimum and maximum estimates). This process proceeds more vigorously under the spillway portion of the dam than beneath the powerhouse portion, and it is especially noticeable beneath section 45.
Translated from Gidrotekhnicheskoe Stroitel'stvo, No. 9, pp. 72–78, September, 1998.  相似文献   

9.
1.  As a result of investigations, formulas were derived which can be used when designing bridge crossings on meandering rivers with wide, developed floodplains passing the bulk of the design discharge during the flood (dependences for determining the value of the maxmum backwater, capacity of the opernings of the bridge crossing, and degree of contraction of the flow in them).
2.  The relative decrease of the capacity of the floodplain opening with increase of its cross-sectional area is due to a decrease of the maximum backwater and increase of the effect of the difference in the resistances of the main channel and floodplain.
3.  From the viewpoint of the capacity of the openings of the bridge crossing, reduction of the water level and subirrigation of the territory, decrease of the degree of contraction of the flow and, consequently, of the development of channel and floodplain deformations, the optimal cross-sectional area of the floodplain opening located in the zone of maximum backwater should amount to 25–50% of the total area of the openings.
4.  Hydraulic calculations performed separately for the main channel and floodplain with the use of the dependences taking into account the interaction of the channel and floodplain flows [7, 8] agree well with the results of the experimental investigations.
5.  The results of the investigations have great significance for developing optimal variants of bridge crossings being designed on meandering rivers.
Translated from Gidrotekhnicheskoe Stroitel'stvo, No. 11, pp. 17–19, November, 1990.  相似文献   

10.
An analysis of the experience in the Soviet Union and in foreign countries with conveyor transportation in the mining industry, as well as with use of conveyors in hydraulic construction shows that the introduction of conveyor transportation in the field of construction of embankment dams in this country, for delivery of earth-rock material from quarries, as well as for carrying raw materials to concentrating plants processing nonmetallic minerals, will make it possible.
1)  To reduce substantially the personnel nees.
2)  To lower significantly the transportation costs for delivery of earth-rock materials to construction sites and to concentrating plants processing nonmetallic mateirals (rubble, gravel, and sand);
3)  To reduce the need for trucks, by replacing them with conveyors;
4)  To increase the rate of delivery of earth-rock materials from quarries for dam, construction and, consequently, to reduce the times of completion.
5)  To reduce the volume of housing, cultural-welfare, and auxiliary-subsidiary construction in owing to the lower needs for personnel in conveyor transportation;
6)  To eliminate the need for constructing a large number of roads with rigid pavements for large-capacity dump trucks;
7)  To raise the technical level of the earth-rock work.
  相似文献   

11.
1.  Provision for stability of slopes is one of the main problems in designing plains PSHS.
2.  The reasons for occurrence and a chain reaction of development of landslide phenomena on the south slope of the area of basic structures of the Zagorsk PSHS were peculiarities of its engineering-geological structure that were not properly taken into account in designing and carrying out construction work.
3.  For the purpose of stabilizing the landslide slope, a system of engineering measures was developed and implemented, including a change in the configuration and structure of the right-bank abutment of the upper-basin levee to the water intake, construction of a banquette, filling of a counterbanquette, draining of moraine loams, grading of the slope, surface water diversion, and monitoring of the state of the slope and elements of the antilandslide protection.
4.  Data from full-scale observatins indicate the effectiveness of the antilandslide measures that were performed and a state of the slope corresponding to criteria for the hydro development's safe operation.
5.  Innovative elements of the system of measures to stabilize the south landslide slope of the Zagorsk PSHS are:
–  the complex nature of measures, providing for the optimum set of criteria with respect to reliability, technological efficiency, construction time, and cost of adjusted expenditures;
–  minimization of one-time and total excavation for the banquette, providing for the least disruption of the slope in the process of construction;
–  draining of moraine loams, which has no known analog;
–  the use of an ejector unwatering system, which provides for minimum adjusted expenditures on construction and operation of the drainage system.
Deceased.  相似文献   

12.
1.  In certain cases of constructing dams salt-containing soils serve as their foundation.
2.  Under these conditions reliable operation of the structures can be provided only by developing special engineering measures to control dissolution.
3.  All existing methods of protecting saliferous foundation soils of hydraulic structures from dissolution can be divided into passive, active, and combined.
4.  The combined methods should be considered the most effective for preventing removal of salts from foundation soils by the seepage flow.
5.  Large-scale field investigations of the work of the combined method of protecting saliferous foundation soils of the planned Lower Kafirnigan hydro development showed its high effectiveness even in the case of complex engineering-geological conditions at the construction site.
6.  Individual elements of the set of dissolution protective measures investigated under field conditions can be used in hydrotechnical and hydropower construction practice.
Translated from Gidrotekhnicheskoe Stroitel'stvo, No. 10, pp. 10–14, October, 1994.  相似文献   

13.
Conclusions  
1.  Gidrospetsproekt should design the groundwater system.
2.  One contractor should drill the wells and operate the groundwater-lowering system.
3.  In connection with the geological conditions, the wells should be of very high quality, for which own enrichment of the filter material (sand of the blanket) and strict control during drilling the wells are necessary.
4.  It is efficient to drill the wells by a 1BA-15V rig with a tool with backwashing.
5.  With respect to piles of the penstock foundation: Drilling the holes for the piles should be done only with casings. To organize 24-h work for increasing productivity. Works on forming the pile heads should be done immediately after concreting the pile. The piles should be tested after each change in the geological conditions.
6.  With respect vertical drainage: the wells should be of high quality, with an enormous safety margin.
Translated from Gidrotekhnicheskoe Stroitel'stvo, No. 10, pp. 29–33, October, 1999.  相似文献   

14.
1.  The designs as well as the total safety factor of concrete-encased steel pressure conduits of operating hydraulic structures were analyzed.
2.  The principles of the existing standards related to calculations of concrete-encased steel pressure conduits were analyzed.
3.  Methods of calculating concrete-encased steel pressure conduits (including forks and distributors), including elements of the inside steel shell and reinforced-concrete part, were developed.
4.  The calculation methods developed were experimental substantiated and tested during designing and constructing domestic and foreign objects.
Translated from Gidrotekhnicheskoe Stroitel'stvo No. 1, pp. 37–44, January, 1999  相似文献   

15.
1.  For locks with a head not exceeding 1.5 of the initial depth in the chamber it is most expedient to use the simplest supply systems of the lock-head type with filling from under the gate.
2.  For heads exceeding the initial depth in the chamber by more than 1.5 times, prevention of the entrainment of air by the flow filling the chamber should be provided. Preference should be given to the scheme with bypass submerged culverts in the upstream head, eliminating air entrainment.
3.  An analysis of the laboratory and onsite data shows that complication of the culvert supply systems from a certain level is not paid back by an acceleration of ship passage and improvement of ship mooring. Thus, for locks with a head on the chamber up to 40 m it is recommended to use a scheme with not more than four outlet sections (schemes 4 and 6 in Fig. 5). The ship mooring conditions for such schemes practically do not limit the chamber filling speed.
4.  An additional supply system can be used for accelerating the filling of high-head locks. The regime of the combined operation of main and additional supply systems is selected by model investigations.
Translated fromGidrotekhnicheskoe Stroitel'stvo, No. 2, pp. 38–41, February, 1989.  相似文献   

16.
Conclusions  
1.  The expediency of hydraulic-fill grading of marshy coastal territories and city dumps for housing construction and recreation park and beach zones was proved practically.
2.  Underwater coastal borrow pits in the shallow-water zone can be used for direct dredging of soil.
3.  In the absence of sand borrow pits, fine-grained loamy sand soils can be used for hydraulic filling the construction sites.
4.  To operate dredges on large water areas under conditions of violent wind-wave action, it is necessary to work out a special works organization plan taking into account the preservation of supply lines, machines, and crew during a storm and under ice conditions in the winter.
5.  The possibility of using the ash of heat and power plants for engineering grading of a marshy territory for housing construction on a pile foundation was proved.
Translated from Gidrotekhnicheskoe Stroitel’stvo, No. 9, pp. 29–33, September, 1997.  相似文献   

17.
Conclusions  
1.  In the upper reservoir of the Zagorsk PSS there are standing waves of a complex frequency spectrum having a virtually undamped character.
2.  The excess of the level of the crest of the upper reservoir embankment of the PSS should be selected with consideration of not only waves caused by meteorological factors but also the presence of standing waves.
3.  The standard systems of measuring the upper pool level of the PSS should provide for averaging the measurements.
4.  To eliminate nonproductive water losses through leaks of the close gate apparatus of the PSS units and increased power losses in the SC regime, it is advisable to provide for the installation of preturbine gates at newly planned PSSs.
Translated from Gidrotekhnicheskoe Stroitel'stvo, No. 10, pp. 39–42, October, 1999.  相似文献   

18.
Conclusions  
1.  Clearing small silted rivers in the Volgograd and Rostov regions by means of floating dredges confirms the expediency of these works for irrigating farmlands, pisciculture, and improving ecology.
2.  Works on clearing and dredging small rivers have their own characteristics, which should be taken into account when working out the technical documents and performing the works.
3.  Simultaneously with channel clearing, comprehensive measures should be taken to prevent erosion of the banks and pollution of the river by wastewaters.
4.  The project documents should be drawn up with consideration of a multipurpose approach to the use of the river’s water resources.
Translated from Gidrotekhnicheskoe Stroitel’stvo, No. 6, pp. 41–44, June, 1998.  相似文献   

19.
1.  A simple, reliable, and ecologically safe design of the drive of a submersible pump and associated devices was developed and thoroughly tested for wide modernization of existing and designing new dredges.
2.  The introduction of dredges with an additional submersible pump makes it possible to increase the depth of excavation, to increase the concentration of the mixture and productivity with a decrease of specific energy expenditures and equipment wear and increase of ecological protection.
Translated from Gidrotekhnicheskoe Stroitel'stvo, No. 1, pp. 43–46, January, 1994.  相似文献   

20.
1.  Small hydrostations under high-mountain conditions should operate with trash racks, devices should be provided for their cleaning from trash and shuga, as well as shuga-deflectors into the diversion canal.
2.  To reduce abrasion of the turbine equipment, it is necessary to provide operation of the suspended-particle settling basins.
3.  Specifications on the assembly of bearings and movable couplings should be developed for conducting maintenance works.
4.  During restoration works the profile of the runner blades should be made strictly according to the template in conformity with the plant drawings.
5.  Extremely necessary is the equipping of hydrostation with means for monitoring the technial parameters (bearing temperature, water pressure in the passage, wobble of the shafting, etc.), observation of the changes in which will make it possible to carry out in good time preventive maintenance and to reduce the probability of occurrence of breakdown.
Translated from Gidrotekhnicheskoe Stroitel'stvo, No. 3, pp. 43–45, March, 1990.  相似文献   

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