RU173350U1 - DRY COOLING HOUSE FOR HOT CLIMATE - Google Patents

Abstract

The utility model relates to dry coolers. The objective of the utility model is to create a cooling tower for cooling heat generating units designed to operate in hot climates without water consumption at ambient air temperatures at ground level of up to 80 ° C, including for cooling the condenser of a steam turbine of a nuclear power plant and the steam part of a turbine as part of a gas turbine plant ATOM-GTU. The technical result is achieved by the special design of the cooling tower, in which its dimensions and parameters are determined by a joint optimization of thermal-hydraulic and environmental calculations. In contrast to the known designs of dry cooling towers, the outer shell is used in the form of a column in which there are segments of transversely streamlined oblique bundles of plate heat exchangers in which the coolant circulating in the closed cooling circuit of the heat generating unit is best cooled by ambient air due to convective heat transfer. Ambient air is taken from the height of the tower, and exhaust hot air is emitted by a turbofan into the stratosphere (for ecology, this is better than warming the ocean), which will allow building nuclear power plants even in the center of the Sahara.

Description

The utility model relates to a power system. More specifically, it relates to dry cooling towers for cooling fuel plants designed to operate in hot climates without water consumption at ambient temperatures at ground level of up to 80 ° C, including for cooling a condenser of a steam turbine of a nuclear power plant and a steam section of gas turbine plants NPP (GTU-NPP).

State of the art

Constructive solutions of dry cooling towers were developed more than 70 years ago and practically did not change much. For NPPs with a steam turbine installation, the Czech dry cooler was first used at the Bilibino NPP (see Dry Biliben NPP Cooling Tower) in Russia in Yakutia, since conventional open water cooling towers do not work at air temperatures up to minus 70 ° С. Non-freezing liquid is used as a coolant in a closed cooling circuit of a condenser of a steam turbine.

In countries with a hot climate, the opposite is true. The surface temperature of the equipment under the scorching sun can reach 100 ° C, and air at ground level up to 80 ° C. The high temperature of the coolant for cooling the condenser of the steam turbine significantly reduces its efficiency and power. For example, at Kudankulam NPP in India, efficiency fluctuates around 33% depending on the temperature of the water from the ocean, cooling the condenser of the steam turbine. To cool the condenser of the steam turbines of nuclear power plants, they are forced to locate them on the ocean, while, for example, in Africa, mutually beneficial economically and politically in cooperation, having mineral deposits and requiring electricity, the states are located just in the depths of the continent, where there are no big water. In these areas, the most profitable source of electricity is a gas turbine unit (GTU-NPP), consisting on one shaft of the gas part of the turbine and the steam part of the turbine, having a common efficiency more than 60%, which allows you to have a reasonable margin of competitiveness.

In hot and dry climatic conditions, the use of known open cooling towers, in which water, for example, for a condenser of a steam turbine of a nuclear power plant, is cooled in the form of falling droplets by an upward flow of ambient air, is unacceptable due to significant evaporation and entrainment of moisture into the surrounding atmosphere, which creates environmental damage . An open cooling tower also requires a significant flow of water to feed the condenser cooling circuit and the use of an appropriate expensive water treatment system.

Essentially a dry cooling tower consists of a large number of air radiators, see the photo in FIG. 1, connected in the direction of flow of the cooled coolant into groups in series, and then parallel to the common stream at the cooling condenser inlet of the steam turbine.

The dry cooler design was taken as an analogue, see FIG. 2 (see Dry Cooling Tower of Biliben NPP), in which heat exchangers from finned tubes 6 are connected at points 2 in parallel-series to groups, in each of which a horizontal air stream 4 with ambient temperature is created at the inlet by fan 7. At the outlet 3 from the heat exchangers of the cooling tower, the coolant for the condenser cooling circuit can be cooled to a temperature of 20-30 ° C higher than the ambient temperature.

Significant disadvantages of dry cooling towers is that even when filtering air from dust in front of the fan (or after), clogging of the radiating surface of the radiators occurs, leading to a significant decrease in the cooling efficiency of the coolant. In the conditions of dust storms, which is typical for hot countries far from the ocean coast, the existing dry cooler structures will generally cease to work properly, which will lead to the inevitable shutdown of a nuclear power plant reactor.

Utility Model Disclosure

The objective of the utility model is to create a cooling tower for cooling heat generating units designed to operate in hot climates without water consumption at ambient temperatures at ground level of up to 80 ° C, including for cooling the condenser of a steam turbine of a nuclear power plant and the steam part of a turbine as part of a gas turbine plant ATOM-GTU.

The technical result consists in improving the characteristics of the coolant in a closed cooling circuit of the condenser of a steam turbine, which allowed us to solve the problem of the utility model.

The technical result is achieved by the special design of the dry cooling tower for a hot climate, in which its dimensions and parameters are determined jointly

optimization heat-hydraulic and environmental calculation and which contains air radiators connected in the course of the cooled coolant in series and parallel to a common external closed cooling circuit, the air flow for cooling in each group of radiators in which the coolant circulating in a closed cooling circuit is cooled. According to a utility model, air radiators consist of segments in the form of oblique bundles of plate heat exchangers, which are located inside an airtight column-shaped cooling tower casing, arranged uniformly in height and circumference relative to the vertical axis of the casing from its wall with a gap in which there are two dividing partitions, the first from the axis of the partition with holes distributed on its surface opposite the entrance of each segment of inclined beams, and the second from the axis of the partition, on one side they create a first channel in the gap between the first partition for supplying segments of inclined beams of fresh air taken by the first air intake in the upper part of the tower at the inlet of the first channel, and on the other hand, creating a second channel in parallel with the wall of the tower body to supply fresh flow to the turbofan inlet air, the intake of which is made by the second air intake at the inlet of the second channel in the upper part of the tower tower; along the axis of the casing there is a central channel, formed around a circumference by a closed vertical partition, which contains, for the exhaust air to exit from the segments of the inclined beams, openings with injectors, which, due to the high-speed air flow, create a vacuum and exhaust air from each segment of the inclined beams into the central channel; along the axis of the tower tower at the bottom of the central channel, to create a high-speed air flow and discharge it into the stratosphere through the nozzle device of the upper part of the central channel, there is a turbofan, which provides the pressure of the fresh air flow taken from the outside of the tower through the second air intake.

In FIG. 3 shows in vertical section the design of a dry cooling tower for a hot climate (hereinafter referred to as the cooling tower), as an option, with a casing 3 in the form of a hexagonal rectangular prism (column) mounted on a foundation 4. In FIG. 3 arrows show the direction of air flow in the cooling tower.

In contrast to the known designs of dry coolers with air radiators, the appearance of which is shown in FIG. 1, in a cooling tower dry for a hot climate, the air radiator consists of segments 1, see FIG. 3, in the form of oblique bundles 2 of plate heat exchangers, which are located inside an airtight casing 3 of a tower-shaped tower, arranged uniformly in height and circumference relative to the vertical axis of the casing 3 from its wall with a gap in which there are two dividing walls 7 and 8. The first from the axis of the partition 8 with the holes 16 distributed on its surface opposite the entrance of each segment 2 of inclined beams, and the second from the axis of the partition 7, on the one hand creating in the gap between the first partition 8 the second channel 9 for supplying segments of inclined beams of fresh air taken by the first air intake 14 in the upper part of the tower at the inlet of the first channel 9, and on the other hand, creating a second channel 6 in parallel with the wall of the tower body for supplying fresh air to the turbofan input 5, the fence is made by the second air intake 15 at the inlet of the second channel 6 in the upper part of the tower tower.

Along the axis of the housing 3 there is a central channel 10, formed around a circumference of a closed vertical partition 11, which contains, for the exhaust air to exit from the segments of the inclined beams, holes 12 with injectors 13, which create due to the high-speed air flow in the central channel 10 a discharge and a suction (suction ) of exhaust air from each segment of the inclined beams 2 to the central channel 10. Along the axis of the tower tower at the bottom of the central channel 10 there is a turbofan 5, to create a high-speed air flow and discharge it into tratosferu through the nozzle device 17 on the top of the central channel 10, Turbo fan 5 provides a flow of fresh air pressure on the inlet channel 10, taking it outside the cooling tower through the second air inlet 15 in its upper part and passing through the second channel 6.

Segments 1 of transversely streamlined oblique beams 2 of plate heat exchangers have air-tight partitions between each other and form a fresh air stream for each segment at its inlet, the flow rate of which through each segment is determined by the degree of rarefaction by injector 13 connected to the outlet 12 of the segment exit, from where exhaust hot air is drawn into the central channel, where it mixes with the high-speed stream of fresh air.

The cooling tower in the upper part at the outlet of the central channel 10 has a nozzle device 17, which, for ejection into the stratosphere of the flow of exhaust air mixed with fresh air, ensures its acceleration to supersonic speed.

The cooling tower has a nozzle device 17, in which dischargers 18 are installed along the perimeter of the outlet of the exhaust air stream mixed with fresh air, changing the viscosity of the boundary layer in the stream to reduce sound noise into the environment.

The cooling tower has a housing 3, the outer surface of which contains a heat-insulating and reflective coating.

Lamellar heat exchangers and all pipelines of the cooling tower have collapsible and soldered flanges of quick assembly, which exclude leakage of the coolant.

The height of the column of the hull 3 of the tower is determined based on weather conditions, i.e. the height of the column is greater than the height of the dust storm above ground level at the point of its installation.

The cooling tower has dust filters on the inlets 14 and 15, and in the lower part of the housing 3 in front of the turbofan at the bend of the fresh air stream has an inertial dust separator 19 with a storage sump.

The cooling tower contains oblique bundles 2 of plate heat exchangers, which are connected, along the cooled coolant, in series and parallel to a common external cooling circuit using collapsible-soldered flanges (the so-called "automatic quick assembly"), eliminating the leakage of the coolant.

The principle of operation of the cooling tower.

Initial state - the circulation circuit for external cooling is correctly prepared and connected. After turning on the turbofan 5, see FIG. 3, there is a discharge in a closed volume under it, into which

fresh air is sucked in through the channel 6 through the air intakes 15 located along the perimeter in the upper part of the housing, and an air flow rate is created in the central channel 10. In the direction of the flow, inertial separators 19 remove dust into the sump.

Upon reaching the nominal air flow rate in the central channel 10, a vacuum occurs in the injectors 13. This vacuum is transmitted through the openings 12 to the segments 1, as a result of which fresh air is sucked into the inclined bundles 2 through the openings 16 in the partition 8. Next, the vacuum is transmitted to the channel 9, where fresh air is sucked in through the air intakes 14 located along the perimeter in the upper part of the cooling tower housing at the inlet of channel 9. In the central channel 10, fresh air and the heated exhaust air are mixed, roshedshego through plate heat exchangers each segment. Next, the mixed stream enters the nozzle device 17, in which it is accelerated to supersonic speed. After passing through the sound barrier, the arresters 18 are turned on, and the sound noise from the supersonic jet exiting the nozzle is reduced.

The angle of inclination of the corridor bundles, consisting of plate heat exchangers, and all other sizes are determined by the joint optimization of heat-hydraulic calculation. The maximum allowable flow rate of hot air discharged into the stratosphere is determined by environmental calculation.

For the practical implementation of a dry cooling tower for a hot climate, a full-scale CFD model can be performed, which allows one to calculate with high accuracy all the necessary optimal structural dimensions.

Industrial applicability.

A dry tower for a hot climate will allow you to build nuclear power plants and thermal power plants with a steam turbine anywhere in the world, especially in regions with a hot climate with air temperatures at ground level up to 80 ° C without the need for binding to large water, the ocean, large bodies of water or small rivers.

Claims (8)

1. A dry cooling tower for a hot climate, containing air radiators connected in series along the cooled coolant in series and parallel to a common external closed cooling circuit, air flow for cooling in each group of radiators in which the coolant circulating in a closed cooling circuit is cooled, characterized the fact that: air radiators consist of segments in the form of oblique bundles of plate heat exchangers, which are located inside an airtight casing of a cooling tower having the column shape, placed uniformly in height and circumference relative to the vertical axis of the housing from its wall with a gap in which there are two dividing partitions, the first from the axis of the partition with openings distributed on its surface opposite the entrance of each segment of inclined beams, and the second from the axis of the partition, on the one hand, creating a first channel in the gap between the first partition for supplying segments of inclined bundles of fresh air taken by the first air intake in the upper part of the cooling tower at the inlet of the first channel la and on the other hand, creates parallel with the wall of the tower housing a second channel for supplying the input flow turbofan fresh air, intake of which is produced a second air intake at the inlet of the second channel at the top of the tower body; along the axis of the casing there is a central channel, formed around a circumference by a closed vertical partition, which contains, for the exhaust air to exit from the segments of the inclined beams, openings with injectors, which, due to the high-speed air flow, create discharge and intake of exhaust air from each segment of the inclined beams into the central channel; along the axis of the tower tower at the bottom of the central channel, to create a high-speed air flow and discharge it into the stratosphere through the nozzle device of the upper part of the central channel, there is a turbofan, which provides the pressure of the fresh air flow taken from the outside of the tower through the second air intake. 2. The tower is dry for a hot climate according to claim 1, characterized in that the segments of transversely streamlined oblique beams, consisting of plate heat exchangers, have air-tight partitions between them, which form a fresh air stream for each segment at its inlet, and there are injectors connected to the outputs of the respective segments of the transversely streamlined oblique beams. 3. The cooling tower is dry for a hot climate according to claim 1, characterized in that in it in the upper part at the outlet of the central channel there is a nozzle device which, for ejecting into the stratosphere, the flow of exhaust air mixed with fresh air, ensures its acceleration to supersonic speed. 4. The cooling tower is dry for a hot climate according to claim 1, characterized in that it has a nozzle device in which arresters are installed along the perimeter of the exhaust air stream mixed with fresh air, changing the viscosity of the boundary layer in the stream to reduce sound noise into the environment . 5. The cooling tower is dry for a hot climate according to claim 1, characterized in that it has a casing, the outer surface of which contains a heat-insulating and reflective coating. 6. The cooling tower is dry for a hot climate according to claim 1, characterized in that the plate heat exchangers and all the pipelines of the cooling tower have collapsible-soldered flanges of quick assembly, eliminating leakage of the coolant. 7. The tower is dry for a hot climate according to claim 1, characterized in that the column height of the tower is determined based on the meteorological conditions of the area, i.e. the height of the column is greater than the height of the dust storm above ground level. 8. The cooling tower is dry for a hot climate according to claim 1, characterized in that it has dust filters on the air intakes in the upper part of the body, and in the lower part of the body in front of the turbofan, has an inertial dust separator with a storage sump at the bend of the fresh air flow.

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