KR100247104B1 - Cooling device for steam turbine for power station - Google Patents

Abstract

The present invention relates to a forced cooling device for a steam turbine for a power plant, comprising: an air manifold (8) for sucking high temperature steam; A device that cools high-temperature air by exchanging steam sucked from a turbine with coolant through an internal subtube and can supply / discharge the outer cell (1a), steam inlet / outlet ducts (1b, 1c), and coolant. An air cooler (1) composed of a channel chamber (1e) and a tube (1d) capable of cooling the hot air by sending cooling water into the apparatus; A vacuum pump 2 driven by a motor to generate a flow of air; It consists of a water / air separator (separator) for separating the water / air passed through the vacuum pump (2).

Description

Forced chiller of steam turbine for power plant

The present invention relates to a forced cooling device of a steam turbine of a thermal power plant / industrial power plant.

If the turbine used in the power plant is damaged and the turbine needs to be disassembled and assembled, it should be cooled to a temperature low enough to open the turbine casing at a high temperature of about 540 ° C.

However, if the turbine is naturally cooled, it takes about 8 to 9 days to cool it to the desired degree, and during this period, maintenance and inspection work cannot be performed simply because of the high temperature inside the turbine. The construction period is long and wasteful economically.

By the way, since the conventional cooling method of the turbine has been operated only by the natural cooling method described above, in this case, it is impossible to immediately insert the maintenance manpower, which has the disadvantage that the system stops for a considerable time, and also delays in the maintenance manpower. The air required for the input and the repair of the steam turbine was considerably long, resulting in economic losses.

However, this loss has been considered inevitable since no specific method or apparatus has been proposed in the country to forcibly cool such steam turbines.

Therefore, when forced cooling is performed by using a forced cooling device within a range within which the metal bodies constituting the turbine rotor, blade, and casing are not overwhelmed, maintenance air of the turbine of the power plant can be shortened and economical. It is beneficial.

For example, when the forced cooling device of the present invention described below can reduce the air by about 3 to 5 days, the maintenance cost of the power generation system can be reduced by shortening the maintenance period.

In addition, the forced turbine cooling apparatus provided by the present invention by forcibly introducing air into the turbine of the high temperature state after the power generation system of the thermal power plant and industrial power plant is stopped to cool the turbine parts such as the rotor, casing of the turbine By using the forced cooling device of the present invention, the cooling rate of the turbine can be adjusted, and the user can increase the utilization of the device by cooling the turbine appropriately for the maintenance and inspection period of the turbine.

In order to achieve the above object, the present invention provides a vacuum pump and the vacuum pump driven by an air manifold that sucks high temperature steam and an air cooler and a motor that cools the high temperature steam sucked from the turbine to generate air flow. The forced cooling system was configured with a water / air separator for separating water / air passed through 2).

1 is an overall schematic diagram connecting the high pressure turbine and the low pressure turbine according to the present invention to a forced cooling device,

Figure 2a is a front view of the combined state of the components of the forced cooling device according to the present invention,

Figure 2b is a side view of the combined state of the components of the forced cooling device according to the present invention,

Figure 2c is a cross-sectional view of the combined state of the components of the forced cooling apparatus according to the present invention,

Figure 3 is a schematic diagram showing the flow of the fluid as a whole piping diagram connecting the forced cooling device of the present invention,

Figure 4a is an assembled plan view showing a base frame of the present invention,

Figure 4b is an assembled front view showing a base frame of the present invention,

Figure 4c is an assembly side view showing a base frame of the present invention,

5A is an assembled front view of the air manifold of the present invention;

5B is an assembled top view of the air manifold of the present invention;

Figure 6a is an assembled front view showing the air cooler of the present invention,

Figure 6b is an assembled side view showing the air cooler of the present invention,

6c is an assembled sectional view showing the air cooler of the present invention;

6D is a front view of the tube sheet of the air cooler of the present invention;

6E is a tube insertion view of the air cooler of the present invention;

6F is a cross-sectional view of the tube sheet of the air cooler of the present invention;

7a is an assembled front view showing a water / air separator according to the present invention;

7b is an assembled top view of the water / air separator according to the present invention.

<Explanation of Drawing Symbols>

1 ... air cooler, 2 ... vacuum pump,

4 ... water / air separator, 6 ... main control panel,

8 ... air manifold, 10 ... base frame,

18 ... Y strainer, 33 ... shield,

a ... high pressure turbine, b ... medium pressure turbine,

c ... low-pressure turbine, e ... condenser,

g ... high temperature / high pressure main engine, i ... vacuum brake,

j ... low temperature reheat pipe, k ... forced chiller.

Hereinafter, the configuration and operation of the forced cooling device of the steam turbine for a power plant according to the present invention will be described in detail with reference to the drawings.

1 is an overall schematic diagram of a high pressure turbine and a low pressure turbine according to the present invention connected to a forced cooling device.

As shown in the figure, the flow of air for cooling the turbine was divided into two lines (g, h). One of the lines (g) is a forced cooling device (k) after cooling the high-pressure turbine (a) by passing the air drawn in the low temperature reheat pipe inlet line through the reheat pipe (j) based on the forced cooling device. And the other line (h) flows air into the condenser (e) through the vacuum brake (i) of the condenser (e) and then passes through the low pressure turbine (c, d) and the low pressure turbine and the medium pressure turbine. Air flows into the medium pressure turbine (b) through the crossover pipe (f) connecting (b) and then into the forced cooling system.

In addition, in order to prevent the cooling of the turbine at high temperature, the air flow was reversed. This reverse flow causes the air in the air to enter the turbine, thereby rapidly cooling the high temperature equipment. This is to prevent damage such as crack breakage caused by thermal stress generated.

Figure 2a shows a front view of the combined state of the components of the forced cooling apparatus according to the present invention, Figure 2b is a side view, Figure 2c shows a cross-sectional view.

As shown in the figure, the forced turbine cooling apparatus of the present invention is a device for cooling by operating the vacuum pump (2) by the power of the motor to suck the high-temperature air in the turbine.

On the base frame 10, an air manifold 8 for collecting hot air flowing from a turbine, an air cooler 1 for cooling (heat exchanging) the hot air with water / cold air, and a cooled medium. A vacuum pump 2 for suction and circulation, a motor 3 for driving the vacuum pump, a water / air separator 4 for separating and discharging the water / cold air, and a forced cooling device of the present invention The main control board 6 and other devices are fastened and fixed by fixing means such as bolts or welding.

All air and water flowed into the forced cooling system flowed through pipes of various sizes, and valves to control the flow of water and air were installed in the middle of each structure and the pipe of the structure.

Here, reference numeral 18 denotes a Y-type strainer (filter), and 33 denotes a protective film.

The function and structure of other detailed components will be described below with reference to FIGS. 3 to 7.

3 is an overall piping diagram connecting the forced cooling device of the present invention, showing a schematic flow of air.

The hot air introduced from the high pressure turbine (a) and the low pressure turbine (c) merges with each other in the air manifold (8) of the forced cooling device through the inlet pipe of the forced cooling device (k) and the globe valve (ii), This enters the air cooler 1 through the pipe. The air introduced in this way is condensed into liquid (water) by heat exchange with the cooling water in the submerged tube through which the cooling water flows, and the cooling water passing through the pipe and the gate valve is sequentially supplied to the air cooler 1. Due to the temperature difference between the coolant and the steam in the high temperature state, the hot air outside the subheat tube is exchanged with the coolant, and the coolant is continuously supplied until the cooling operation is completed. After the hot steam is separated from the air cooler 1 into water and air, it is passed through a check valve which is an inlet valve of the vacuum pump 2 through a flexible hose and a pipe. Flows into). This vacuum pump 2 is operated by the motor 3, forcibly generating a flow of water / air and supplying it to the water / air separator 4. In this way, the water and air supplied to the water / air separator 4 are discharged to the atmosphere or through the lower outlet gate valve and the pipe, respectively.

4A is an assembled plan view of the base frame of the present invention, FIG. 4B is a front view, and FIG. 4C is a side view.

The base frame 10 to which the forced cooling device of the present invention is installed is composed of a frame 10a, a pad 10c, a structure lift lug 10d, a ladle 10e, and the frame 10a is a forced cooling device. The size can be adjusted in accordance with the capacity of and the joint can be fixed by means of welding or the like.

The check plate 10b is welded to the bottom surface of the frame 10a so that the inspector can safely check the operation of the components, and the pad 10c is located inside both corners for fixing and safety of the frame 10a. Fixed by welding at.

The lift lug 10d is installed to facilitate the movement when the forced cooling device is moved, and the ladle 10e is easily lifted by the inspector when checking whether each component of the forced cooling device is operating normally. To get off.

5A is an assembled front view of the air manifold of the present invention, and FIG. 5B is a plan view.

The air manifold 8 is a kind of air collecting tube for concentrating high temperature air discharged from the turbine into one header, and the body 8a, the upper and lower caps 8b and 8c, and the leg 8d. And a guard net, inlet and outlet flanges 8h and 8f, support portions 8j, liquid outlets 8k, vapor inlets and outlets 8l and 8m, and neck portions 8g and 8i.

The air manifold 8 is a single cell in which the upper and lower caps 8b and 8c are welded to the cylindrical body 8a, and two vapors provided with air flowing from the turbine to the circumferential surface of the body 8a. The inlet pipe 8l is provided, and the steam outlet pipe 8m which can discharge high temperature air is provided in the upper part. Three legs 8d for supporting the air manifold 8 are placed and supported at the bottom, and the liquid in the air introduced from the turbine is collected at the bottom of the manifold 8, and out through the liquid outlet 8k. Discharged.

Figure 6a is an assembled front view of the air cooler of the present invention, Figure 6b is a side view, Figure 6c is a sectional view, Figure 6d is a front view of the tube sheet, Figure 6e is a tube insertion view, Figure 6f is a tube sheet sectional view.

This is a device that cools the hot air collected in the air manifold by exchanging heat with the coolant through the inner subtube.

The air cooler (1) is composed of a vapor inlet duct (1b) and a gas outlet duct (1c) installed on the left and right sides of the outer cell (1a), the channel chamber (1e) for supplying cooling water to both sides is It is installed.

The coolant flows into the coolant inlet flange 1u and then collects in the channel chamber and passes back through one cooling tube 1d to the opposite channel chamber. The cooling water collected in this way is discharged to the outlet flange 1v past the other cooling tube 1d.

The cooling tube 1d is fixed to the tube sheet 1i attached to both sides of the outlet flange, and each tube and the tube sheet are fixed by expansion and welding so that the cooling water does not leak outwardly, Vibration of the tube caused by the coolant flow is prevented by the baffle plate. In addition, the packing 1m is interposed so that cooling water does not leak between both chamber flanges and the end plate 1k, and is fixed by the stud bolt 11.

The pass part plate 1q divides the cooling tube 1d into four and allows the cooling water to flow up and down well, and the support birds 1r serve to support the air cooler 1 to the frame. The liquid outlet pipes 1w of both chamber flanges are installed to remove impurities in the cooling water or to observe the flow of the cooling water, and the lifting lugs 1t are used to facilitate the movement of the air cooler 1 during manufacture. Produced.

7a and 7b is an assembly view showing a water / air separator according to the present invention, showing the manufacturing of the tube sheet and the welding method of the tube and tube sheet.

A vacuum pump that sucks high temperature steam is operated by a motor as a device that introduces high temperature air sucked inside the turbine into the water / air separator 4 via an air cooler.

In the vacuum pump, the water supplied from the cooling water flows along the wall of the casing by the rotational displacement of the rotating plate inside the pump, thereby cooling the cooled air and water of the air cooler.

Water and air introduced by the vacuum pump flow into the flange 4c of the water / air separator 4, the air is discharged to the air outlet 4j, and the water is discharged out by the water outlet 4k. The support (4g) serves to support the water / air separator (4), the manhole is used to check the water / air separator (4).

As described above, the forced cooling device of the present invention is easily configured for transportation, which can be quickly installed during periodic inspection of the turbine and can shorten the maintenance period, thereby reducing costs and increasing power sales. It is expected to be economical and shorten the recovery period due to emergency stop, thereby reducing the accompanying costs associated with the air shortening.

In addition, the device of the present invention can be installed as a temporary facility or a permanent facility, the design can be changed to medium / small according to the capacity of the turbine, there is an advantage that can be reconfigured to the optimal system according to the suction capacity, There is an advantage that can properly adjust the cooling rate of the turbine.

Claims (2)

In the forced cooling device of the steam turbine for power plants, An air manifold (8) for sucking hot steam; An air cooler 1 for cooling the sucked steam; A vacuum pump 2 driven by a motor to generate a flow of air; And, water / air separator (4) for separating the water and air passing through the vacuum pump (2); Forced cooling of the steam turbine for power plants, characterized in that consisting of. The method of claim 1, The air cooler 1 An outer cell 1a; Vapor inlet / outlet ducts 1b and 1c; A channel chamber 1e capable of supplying / discharging cooling water; A tube 1d for flowing cooling water to exchange heat with hot air; Forced cooling of steam turbines for power plants, characterized in that consisting of.

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