RU2275463C2 - Turbine water conveyance structure - Google Patents

Abstract

FIELD: hydraulic engineering, particularly water conveyance structures of hydroelectric power plants and hydroelectric pumped storage power plants.

SUBSTANCE: water conveyance structure comprises composite reinforced concrete pipeline located at prepared base and provided with enclosing structure with covering forming cavity above prepared base. Pipeline is located inside the cavity. The water conveyance structure is provided with air heating means to heat air inside the cavity in cold period up to temperature exceeding 0°C. In the case of composite reinforced concrete pipelines usage the pipelines are located one near another and the enclosing structure covering defines cavity for all pipelines receiving. The covering may be at least partly formed of translucent material.

EFFECT: increased control reliability and structure life, reduced maintenance costs.

4 cl, 2 ex, 4 dwg

Description

The invention relates to the field of hydraulic engineering and can be used in the construction of waterworks in the form of steel-reinforced concrete pressure head turbine pipelines at a hydroelectric station (HPP) and a pumped storage station (PSP), which are exposed to significant temperature drops and atmospheric precipitation due to the local climate.

Known turbine waterworks made in the form of a pipeline of plate metal (1).

The disadvantages of such a water supply structure are its high cost, insufficient reliability in the case of a large diameter pipeline and its fragility due to corrosion of the pipeline exposed to atmospheric action.

Closest to the proposed technical solution is a turbine waterworks subject to atmospheric influences due to the local climate, including a steel-reinforced concrete pipeline located on a prepared foundation (2 or 3).

A steel-reinforced concrete pipeline consists of two elements working together: an inner steel (metal) lining and an outer reinforced concrete shell - in sources they are often called shells, respectively, steel and reinforced concrete. Steel lining ensures the tightness of the pipeline, thereby preventing the direct impact of the water flow on the reinforced concrete shell, and at the same time perceives part of the water pressure. The reinforced concrete sheath perceives the rest of the water pressure, and also protects the steel lining from corrosion. In steel-reinforced concrete pipelines, even at high pressures, steel linings of relatively small thickness are used, which simplifies the manufacture of pipelines. They are more economical than metal pipelines and more reliable and safe for the power plant in the event of a rupture in the steel lining pipeline. At a number of PSPPs (Zagorskaya, Kaisiadorskaya), such pipelines operate under pressure of more than 100 meters, have an internal diameter of 7.5 meters and are cut into sections along the length of the temperature-sedimentary expansion joints. In the case of the dam scheme of hydropower installations, steel-reinforced concrete pipelines are often carried to the lower edge of the station part of the concrete dam. The diameter of such completed pipelines reached 12.4 meters - the Sansya (Three Gorges) waterworks in the PRC (4).

A water supply structure with steel-reinforced concrete pipelines is not reliable enough, not durable enough and difficult to use for the following reasons.

1. The outer surface of the pipeline is constantly washed by the air of the area, the temperature differences (fluctuations) of which in severe climatic conditions during the year reach a value of 70 ° C or more. This leads to the opening of intersectional joints to a value of 0.025 meters or more (2), which limits the length of the section and makes the expansion joints structurally complex, labor-consuming to manufacture and not reliable due to the rapid wear of the sealing element (5).

2. The influence of temperature changes substantially determines the formation of a system of cracks in a reinforced concrete shell operating in a complex stress-strain state, primarily at the joints between precast rings, which often, usually in winter, exceed acceptable values. This reduces the durability and corrosion resistance of the pipeline, and in the event of a defect in the steel lining in the pipeline, a leak forms, which also forms ice in the winter.

3. High demands on frost resistance are imposed on the concrete of the pipeline shell and on the concrete of the base. This is due to the fact that through the resulting cracks in the water falls precipitation water. Water also enters the concrete from the inside, in the event of a leak in the steel lining. This water is unfavorable, with the creation of thermo-humid gradients, distributed in concrete, which sharply reduces its frost resistance.

4. Seasonal freezing-thawing of the base causes deformations in it, which complicates the work of expansion joints in the pipeline, turning them from temperature to temperature-sedimentary.

5. High deformations of a section in the direction of its generatrix create additional loads on the base and can damage its elements, for example, a pile grillage (6).

6. The temperature of the water in the reservoir, for example, at the Zagorskaya PSPP during the winter period drops to +0.1 -0.3 ° С. If the unit is interrupted for more than two days, dangerous ice formation in the pipeline is possible (2).

7. The complexity and lack of reliability of control over the operation of the pipeline in the winter season.

The task to which the invention is directed is to increase the reliability of a water supply structure and simplify its operation. The technical result from the use of the invention is to reduce temperature and sedimentary deformations along the length of the pipeline by reducing the effect of temperature changes in the air of the area on the pipeline and on its base; in preventing atmospheric precipitation; in preventing them from cycles of variable freezing and thawing; to simplify and increase the reliability of control over the operation of a water supply system.

The problem is solved, and the technical result is achieved by the fact that the turbine water supply structure is exposed to atmospheric influences due to the local climate, including a steel-reinforced concrete pipeline located on the prepared base, according to the invention it is provided with a walling with a coating that forms a cavity together with the prepared base, and the pipeline located inside the cavity, and the water supply structure itself is equipped with means for heating the air in this cavity in olodnoe season. The tool provides heating of the air in the cavity to a temperature exceeding zero degrees Celsius. In the case of the inclusion of a group of steel-reinforced concrete pipelines located in close proximity to each other by the water supply structure, the cover of the enclosing structure together with the prepared base forms a cavity containing the entire group of pipelines inside. It is advisable to perform the coating at least partially from a translucent material.

The essence of the technical solution consists in creating a heated cavity by means of the enclosing structure, providing around the steel-reinforced concrete pipelines and over the prepared base a temperature and humidity regime close to optimal, namely: the temperature in the cavity is always positive and, if possible, close to the temperature of the water in the pipeline, and the cavity itself is protected from precipitation. This greatly reduces temperature deformations in pipelines and in the base, increases the frost resistance of concrete in them, while simultaneously preventing cycles of variable freezing and repulsion of concrete.

The invention is illustrated by drawings, which schematically depict:

figure 1 - General view of the Zagorsk PSP, proposed by the invention, the enclosing structure in this drawing is not conventionally shown;

figure 2 is a longitudinal section through a water supply structure;

figure 3 is a section along aa in figure 1;

figure 4 - water supply structure of a hydroelectric power station with steel-reinforced concrete pipelines located on the lower edge of the station part of the concrete dam, a longitudinal section.

Example 1. The turbine water supply structure of the PSPP includes a group of steel-reinforced concrete pipelines 1 (Fig. 1), some ends of which are connected to a water intake 2, which takes water from the upper pool 3 or discharges water into it, and the others, with the PSPP building 4, which is carried out using reversible (turbopump) units 5 release water into the lower pool 6 or take water from it. Pipelines 1 are located in close proximity to each other on the prepared in the direction of the slope base 7 (figure 2) and along the length of the temperature-sediment compensators 8 are divided into sections 9. In the cross section, each pipe 1 has a circular cross section (figure 3) and consists from the inner steel lining 10 and the reinforced concrete shell 11 working together with it. Pipeline 1, with its supporting parts 12, transfers loads to the base 7, which includes ranbalki 13, grillages 14 and concrete piles 15, made in non-rock and floor accelerated soils 16 of the base 7. In addition, the water supply structure is provided with a building envelope 17 with a heat-shielding coating 18, which forms a cavity 19 above the prepared base 7. All pipelines 1 are located inside the cavity 19, which is equipped with means for heating air in it during the cold season mainly to a temperature of exceeding zero degrees Celsius.

The heat-insulating coating 18 is made mostly of translucent material in the form of safe glazing. The cavity 19 is heated by water pipes 20 and, for example, by electric heaters (not shown). The heating pipes 20 are in communication with the cooling system of the equipment of the PSPP building 4. In addition, warm air is supplied to the cavity 19 from the ventilation system of the PSPP building 4 with an air-heating unit (not shown) in the cold season.

At the junctions of the enclosing structure 17 to the water intake 2 and the PSPP building 4, cargo openings 21 are made in it, which are serviced by cranes 22. In the heated cavity 19, passages, stairs, platforms and elevators, which are developed by conventional design and on the drawings are not shown.

The enclosing structure 17 is carried out simultaneously with the construction of pipelines 1 or during their operation with the PSP in operation. In this case, the configuration of the roofing part of the building envelope 17 is determined by the project depending on local conditions, the methods and mechanisms used to create the building envelope 17, and also on the methods and means selected for removing snow from its roofing part.

Waterworks PSP is operated and operates as follows.

In the warm season, due to the cooling effect of the water flowing through the pipelines 1, a positive temperature is established in the cavity 19, which is intermediate between the water temperature in the pipelines 1 and the outdoor temperature of the area. In this case, the temperature differences in the cavity 19, compared with the temperature differences on the ground, significantly, up to half, are reduced. At the same time, the heat-protective coating 18 prevents atmospheric precipitation from entering the cavity. In the cold season, due to heating in the cavity 19, a positive temperature is constantly maintained, usually equal to the temperature of the water in the pipelines 1, which at the PSP at this time is in the range 1-3 ° C. At the same time, both temperature differences in the cavity 19 and cycles of variable thawing and thawing of pipelines 1 and their bases are almost completely prevented.

All this brings the temperature and humidity conditions in the cavity 19 close to optimal for pipelines 1 and their base 7. In addition, the water supply structure can be equipped with a means for regulating (reducing) the humidity in the air filling the cavity. As a result of all this, the reliability and durability of the water supply structure are increased and its operation is simplified.

In the case of turning off the heating in the cold season, the temperature in the cavity 19 is set significantly higher than the temperature of the outside air and with smaller differences, which, although to a lesser extent, also ensures the achievement of the previously indicated technical result.

Example 2. The turbine water supply structure of a hydroelectric power station includes a group of steel-reinforced concrete pipelines 23 (Fig. 4) located on the lower edge 24 of the station part of the concrete dam 25, and is additionally equipped with a building envelope 26, the heat-protective coating 27 of which together with the lower edge 24 forms a cavity 28 containing includes all pipelines 23. The bottom face 24 of the concrete dam 25 has a multi-stage appearance and is a well-prepared base for pipelines. The cavity 28 is equipped with means (not shown) for heating air in it.

Such a water supply facility works similarly to that previously described in Example 1 with a similar technical result: creation of a temperature-humidity regime in the reinforced concrete shell of the pipeline that is close to optimal.

At the same time, in the cold season, the dam 25 concrete is heated pre-heated at its lower edge 24. As a result, a more favorable temperature regime is created in the dam body, namely: the concrete temperature at the lower edge of the dam is positive throughout the year. This provides a useful additional compression of concrete at the top face 29 of the dam 25 and the soil at its base 30, which improves the stress-strain state of the concrete dam.

The water supply facility presented in examples 1 and 2 is intended for areas with harsh and especially harsh climatic conditions, when high temperature differences on the ground during the year occur around zero degrees Celsius. In other climatic conditions, when the differences occur within positive temperatures, the feasibility of creating an artificial climate for steel-reinforced concrete pipelines through the enclosing structure is clearly not visible.

Information sources

1. Arkhipov A.M. Turbine conduits with a steel shell. - LO, Energy, 1973, S.5-20.

2. Berezinsky S.A., Egorov A.V., Lashmanova B.C., Polinkovsky I.A. The design of the pipelines of the PSPP // Hydrotechnical construction, 1985, No. 4.

3. A guide for the design of steel-reinforced concrete structures of hydraulic structures: P-780-83 / Hydroproject. L., 1983.

4. Rubin O.D., Lisichkin S.E., Nikolaev B.A., Kamnev N.M. Features of the calculation and design of steel-reinforced concrete pressure water conduits // Hydrotechnical construction, 1999, No. 1.

5. Sedykh Yu.R., Semenenok S.N., Magruk V.I., Yanovsky A.P. Repair work to prevent leaks in the structures of the Zagorsk PSP // Hydrotechnical construction, 1997, No. 4.

6. Berezinsky S.A., Kogan E.A., Mgalobelov Yu.B., Solovieva L.D. The study of the conditions of joint work of prefabricated steel-reinforced concrete water conduit and pile grillage // Hydrotechnical construction, 1985, No. 8.

Claims (4)

1. A turbine water supply structure exposed to the atmospheric effects of the local climate, including a steel-reinforced concrete pipeline located on a prepared base, characterized in that it is provided with a walling with a coating forming a cavity above the prepared base, while the pipeline is located inside the cavity, and the water supply structure itself is provided means for heating the air in this cavity in the cold season. 2. The structure according to claim 1, characterized in that it is equipped with a means for heating the air in the cavity to a temperature exceeding 0 ° C. 3. The construction according to claim 1, characterized in that if it includes a group of steel-reinforced concrete pipelines located in close proximity to each other, the coating of the enclosing structure forms a cavity over the prepared base that encloses the entire group of pipelines. 4. The construction according to claim 1 or 2, characterized in that the coating is made at least partially of translucent material.

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