A device and method for reducing the dissolved oxygen content of cooling water in a generator

Abstract

A device and method for reducing the dissolved oxygen content of cooling water in a generator, belonging to the field of power generation, includes an internal cooling water tank, characterized in that: it also includes a catalytic tank; a catalyst frame is arranged in the catalytic tank; a hanger is arranged between the catalyst frame and the inner wall of the catalytic tank; a connecting pipe is arranged between the catalytic tank and the internal cooling water tank. The catalytic tank is arranged above the internal cooling water tank, and the hydrogen leaked from the stator chamber of the generator in the internal cooling water tank and the dissolved oxygen in the internal cooling water diffused from the internal cooling water are diffused into the catalytic tank through the connecting pipe, and the hydrogen and oxygen react under the action of the catalyst to produce water, so that the oxygen content in the internal cooling water tank and the catalytic tank is reduced, causing the dissolved oxygen in the internal cooling water tank to continuously diffuse out, and continue to react with hydrogen under the action of the palladium catalyst, so that the dissolved oxygen content in the internal cooling water is gradually reduced, and finally the purpose of reducing the dissolved oxygen content in the internal cooling water is achieved.

Description

Technical Field

[0001] The invention belongs to the field of power generation, and in particular relates to a device and a method for reducing the amount of dissolved oxygen in cooling water in a generator by utilizing hydrogen leakage. Background Art

[0002] In the field of power generation, the "water-hydrogen-hydrogen" cooling method is widely used in large steam turbine generators. Under this cooling method, the generator rotor and stator core are cooled by hydrogen, and the hollow stator winding is cooled by internal cooling water. There is hydrogen leakage during the normal operation of the "water-hydrogen-hydrogen" cooled steam turbine generator. The hydrogen pressure in the stator chamber is greater than the internal cooling water pressure of the stator wire rod. Hydrogen penetrates into the internal cooling water through the generator end wire rod to the water conduit ring and the polytetrafluoroethylene insulated water pipe at the generator outlet. During the circulation process driven by the water pump, the hydrogen is transported and accumulated at the top of the internal cooling water tank. At the same time, there is a certain loss of internal cooling water. Most generators use desalted water to regularly replenish the internal cooling water, and the desalted water contains oxygen. During the circulation process driven by the water pump, some oxygen evaporates from the internal cooling water and accumulates at the top of the internal cooling water tank.

[0003] The quality of internal cooling water has an important impact on the normal operation of the generator. The pH value, conductivity and dissolved oxygen content of the internal cooling water are important quality parameters of the internal cooling water. The national standard DL 801-2010 "Technical requirements for internal cooling water quality and systems for large generators" stipulates that when the pH value of the internal cooling water is between 8.0-9.0 (25°C), there is no additional requirement for dissolved oxygen. However, when the pH value of the internal cooling water is between 7.0-9.0 (25°C), the dissolved oxygen content should be less than 30μg / L. If the dissolved oxygen content is between 200μg / L-300μg / L at this time, the corrosion rate of copper is the highest, which will cause corrosion of the stator winding copper rods and have an adverse effect on the safe operation of the generator. Measures need to be taken to control the dissolved oxygen content of the internal cooling water. Summary of the invention

[0004] The present invention aims to solve the above problems and provides a device and method for reducing the dissolved oxygen content of cooling water in a generator, so as to reduce the dissolved oxygen content of cooling water in the generator at a low cost.

[0005] The device for reducing the dissolved oxygen content of cooling water in a generator according to the present invention comprises a catalytic tank and an internal cooling water tank; a catalyst frame is arranged in the catalytic tank; a hanger is arranged between the catalyst frame and the inner wall of the catalytic tank; the catalyst frame is fixed by the hanger, and a connecting pipe is arranged between the catalytic tank and the internal cooling water tank; the height of the catalytic tank in the vertical direction is greater than the height of the internal cooling water tank in the vertical direction; a catalyst is arranged in the catalyst frame.

[0006] The device for reducing the dissolved oxygen content of cooling water in the generator according to the present invention comprises a connecting pipe including a first connecting pipe and a second connecting pipe; a connecting valve and a connecting pipe flange are sequentially arranged on the first connecting pipe; a second connecting interface and a first connecting interface are sequentially arranged on the side wall of the catalytic tank from top to bottom; the lower end of the first connecting pipe is connected to the internal cooling water tank, and the upper end of the first connecting pipe is connected to the first connecting interface; the lower end of the second connecting pipe is connected to the aforementioned connecting valve, and the upper end of the second connecting pipe is connected to the second connecting interface. The first connecting pipe is used to connect the catalytic tank with the internal cooling water tank, and is connected to the internal cooling water tank body or the internal cooling water tank pipeline through the connecting pipe flange. After the second connecting pipe is downwardly connected to the first connecting pipe outside the catalytic tank, the first connecting pipe continues to be led out to the side and downward and is installed with a connecting valve, and a connecting pipe flange is installed on the outside of the connecting valve.

[0007] In the device for reducing the amount of dissolved oxygen in cooling water of a generator of the present invention, an exhaust pipe is arranged at the top of the catalyst tank; an exhaust valve and an exhaust pipe flange are arranged on the exhaust pipe in sequence. The exhaust pipe is used to discharge the gas in the catalyst tank to prevent gas accumulation at the top of the catalyst tank, and the exhaust valve controls the on-off of the exhaust pipe.

[0008] In the device for reducing the dissolved oxygen content of cooling water in the generator of the present invention, a drain pipe is arranged at the bottom of the catalyst tank; a drain valve and a drain pipe flange are arranged on the drain pipe in sequence. The drain pipe is used to drain the water in the catalyst tank, and the drain valve controls the on-off of the drain pipe.

[0009] The device for reducing the dissolved oxygen content of cooling water in the generator of the present invention comprises four hangers symmetrically arranged; a water baffle is arranged on the hanger; the water baffle is located directly above the catalyst frame, and is used to prevent water from flowing to the catalyst.

[0010] The device for reducing the dissolved oxygen content of cooling water in the generator of the present invention comprises: a hand hole cover flange is provided on one side of the catalytic tank; a hand hole cover is provided on the hand hole cover flange; the hand hole cover is fixed to the catalytic tank through the hand hole cover flange, and the hand hole cover is opened for repair and maintenance of the catalytic tank; an observation window is provided on the hand hole cover; a sealing ring is provided on the edge of the hand hole cover. The hand hole cover maintains a sealing effect through the sealing ring, and the internal situation of the catalytic tank can be observed through the observation window on the hand hole cover.

[0011] In the device for reducing the dissolved oxygen content of cooling water in the generator of the present invention, the catalytic tank is cylindrical; the aforementioned second connecting interface is located at half of the vertical height of the catalytic tank; the first connecting interface is located between the second connecting interface and the bottom end of the catalytic tank. The connecting interfaces are set at different heights. When water accumulates under the catalytic tank, the excess accumulated water flows into the first connecting pipe located below the side of the catalytic tank after filtering out impurities through the connecting pipe filter, and finally flows into the internal cooling water tank. When the connecting pipe filter is soaked by the accumulated water and the air permeability decreases, the catalytic tank maintains good communication with the internal cooling water tank through the second connecting pipe. The aforementioned connecting valve controls the connection and disconnection of the first connecting pipe, the second connecting pipe and the internal cooling water tank.

[0012] In the device for reducing the dissolved oxygen content of cooling water in the generator of the present invention, an exhaust pipe filter is provided at one end of the exhaust pipe connected to the catalytic tank; a connecting pipe filter is provided at the first connecting interface. The exhaust pipe filter is used to prevent dirt from entering the catalytic tank from the exhaust pipe.

[0013] In the device for reducing the dissolved oxygen content in cooling water of a generator according to the present invention, the first connecting interface is located at one quarter of the disposal height of the catalytic tank.

[0014] The device for reducing the dissolved oxygen content of cooling water in a generator of the present invention is a method for reducing the dissolved oxygen content of cooling water in a generator. A catalytic tank is arranged above the inner cooling water tank, and the leaked hydrogen from the stator chamber of the generator in the inner cooling water tank and the dissolved oxygen in the inner cooling water diffused from the inner cooling water are diffused into the catalytic tank through a connecting pipe. The hydrogen and oxygen react chemically under the action of the catalyst and produce water, so that the oxygen content in the inner cooling water tank and the catalytic tank is reduced, thereby reducing the dissolved oxygen content in the inner cooling water.

[0015] The device and method for reducing dissolved oxygen in cooling water of a generator disclosed in the present invention reduce the oxygen content in the cooling water tank and the catalytic tank, causing the dissolved oxygen in the cooling water tank to diffuse out continuously and continue to react with hydrogen under the action of the catalyst, so that the dissolved oxygen content in the cooling water is gradually reduced, thereby achieving the purpose of reducing the dissolved oxygen in the cooling water, greatly reducing the water replenishment frequency of the cooling water system compared with other systems, having a simple structure and being suitable for popularization and application. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the structure of the device for reducing the dissolved oxygen content of cooling water in a generator according to the present invention;

[0017] Figure 2 This is a schematic diagram of the installation method of the first embodiment of the device for reducing the dissolved oxygen content of cooling water in a generator according to the present invention;

[0018] Figure 3 This is a schematic diagram of the installation method of the second embodiment of the device for reducing the dissolved oxygen content of cooling water in a generator according to the present invention;

[0019] Among them, 1-catalytic tank, 11-exhaust valve, 111-exhaust pipe, 112-exhaust pipe flange, 12-drain valve, 121-drain pipe, 122-drain pipe flange, 13-connecting valve, 131-first connecting pipe, 132-second connecting pipe, 133-connecting pipe flange, 14-hand hole cover, 141-sealing ring, 142-observation window, 143-hand hole cover flange, 15-exhaust pipe filter, 16-connecting pipe filter, 17-hanger, 18-water baffle, 19-catalyst frame, 110-catalyst, 2-internal cooling water tank, 21-internal cooling water tank exhaust pipe, 22-internal cooling water tank exhaust valve, 3-bracket, 31-bracket seat, 4-power plant drain pipe, 5-ground. DETAILED DESCRIPTION

[0020] The device and method for reducing the dissolved oxygen content in cooling water of a generator according to the present invention are described in detail below with reference to the accompanying drawings and embodiments.

[0021] Embodiment 1

[0022] The device for reducing the dissolved oxygen content of the internal cooling water of the generator of the present invention comprises a catalyst tank 1 and an internal cooling water tank 2; Figure 1As shown, a catalyst frame 19 is provided in the catalytic tank 1; a hanger 17 is provided between the catalyst frame 19 and the inner wall of the catalytic tank 1; a connecting pipe is provided between the catalytic tank 1 and the inner cooling water tank 2; the height of the catalytic tank 1 in the vertical direction is greater than the height of the inner cooling water tank 2 in the vertical direction; a catalyst 110 is provided in the catalyst frame 19, and in this embodiment, the catalyst 110 is a palladium catalyst 110, and the palladium catalyst 110 is used to catalyze the reaction of hydrogen and oxygen to produce water. The connecting pipe includes a first connecting pipe 131 and a second connecting pipe 132; a connecting valve 13 and a connecting pipe flange 133 are provided on the first connecting pipe 131 in sequence; a second connecting interface and a first connecting interface are provided on the side wall of the catalytic tank 1 from top to bottom in sequence; the lower end of the first connecting pipe 131 is connected to the inner cooling water tank 2, and the upper end of the first connecting pipe 131 is connected to the first connecting interface; the lower end of the second connecting pipe 132 is connected to the aforementioned connecting valve 13, and the upper end of the second connecting pipe 132 is connected to the second connecting interface. An exhaust pipe 111 is provided at the top of the catalytic tank 1; an exhaust valve 11 and an exhaust pipe flange 112 are provided on the exhaust pipe 111 in sequence. A drain pipe 121 is provided at the bottom of the catalytic tank 1; a drain valve 12 and a drain pipe flange 122 are provided on the drain pipe 121 in sequence. Two hangers 17 are symmetrically provided; a water baffle 18 is provided on the hanger 17; the water baffle 18 is located directly above the catalyst frame 19. A hand hole cover flange 143 is provided on one side of the catalytic tank 1; a hand hole cover 14 is provided on the hand hole cover flange 143; the hand hole cover 14 is fixed to the catalytic tank 1 through the hand hole cover flange 143; an observation window 142 is provided on the hand hole cover 14; a sealing ring 141 is provided on the edge of the hand hole cover 14. The catalytic tank 1 is cylindrical; the aforementioned second connecting interface is located at half of the vertical height of the catalytic tank 1; the first connecting interface is located at one quarter of the disposal height of the catalytic tank 1, and an exhaust pipe filter 15 is provided at one end of the exhaust pipe 111 connected to the catalytic tank 1; a connecting pipe filter 16 is provided at the first connecting interface.

[0023] like Figure 2 As shown, in this embodiment, the device for reducing the dissolved oxygen content in the cooling water of the generator is installed as follows: the catalytic tank 1 is installed above the side of the internal cooling water tank 2 and fixed by the bracket 3, one group of brackets 3 connects the catalytic tank 1 and the internal cooling water tank 2, and the other group of brackets 3 connects the catalytic tank 1 and the bracket seat 31, and the bracket seat 31 is installed on the ground 5.

[0024] The inner cooling water tank 2 is provided with an inner cooling water tank exhaust pipe 21, on which an inner cooling water tank exhaust valve 22 is connected in series. The exhaust pipe 111 is connected to the inner cooling water tank exhaust pipe 21 at the upper part of the inner cooling water tank exhaust valve 22 through an exhaust pipe flange 112. The first connecting pipe 131 of the catalytic tank 1 is connected to the inner cooling water tank 2 through a connecting pipe flange 133. The drain pipe 121 of the catalytic tank 1 is suspended in the air through a drain pipe flange 122.

[0025] By means of a device for reducing the dissolved oxygen content in the generator's inner cooling water, the catalytic tank 1 is located above the stator cooling water tank, hydrogen leaked from the generator stator chamber into the inner cooling water tank 2 and dissolved oxygen in the inner cooling water diffused from the inner cooling water are diffused into the catalytic tank 1 through the first connecting pipe 131 and the second connecting pipe 132, and the leaked hydrogen and oxygen react chemically under the action of the palladium catalyst 110 to produce water, and the chemical reaction reduces the oxygen content in the inner cooling water tank 2 and the catalytic tank 1, causing the dissolved oxygen in the inner cooling water tank 2 to continuously diffuse out, and continue to react with the leaked hydrogen under the action of the palladium catalyst 110, thereby ultimately achieving the purpose of reducing the dissolved oxygen content in the inner cooling water.

[0026] Embodiment 2

[0027] Based on the first embodiment, Figure 3 As shown, in this embodiment, the device for reducing the dissolved oxygen content in the cooling water of the generator is installed as follows: the catalytic tank 1 is installed above the side of the internal cooling water tank 2 and fixed by a bracket 3, one group of brackets 3 connects the catalytic tank 1 and the internal cooling water tank 2, and another group of brackets 3 connects the catalytic tank 1 and the bracket seat 31, and the bracket seat 31 is fixed to the ground 5.

[0028] The internal cooling water tank 2 is equipped with an internal cooling water tank exhaust pipe 21, on which an internal cooling water tank exhaust valve 22 is connected in series. The exhaust pipe 111 is connected to the internal cooling water tank exhaust pipe 21 at the upper part of the internal cooling water tank exhaust valve 22 through an exhaust pipe flange 112. The first connecting pipe 131 of the catalytic tank 1 is connected to the internal cooling water tank exhaust pipe 21 at the lower part of the internal cooling water tank exhaust valve 22 through a connecting pipe flange 133. The drain pipe 121 of the catalytic tank 1 is connected to the power plant drain pipe 4 through a drain pipe flange 122, which can more conveniently remove the accumulated water in the catalytic tank 1.

[0029] By means of a device for reducing the dissolved oxygen content in the generator's inner cooling water, the catalytic tank 1 is located above the stator cooling water tank, hydrogen leaked from the generator stator chamber into the inner cooling water tank 2 and dissolved oxygen in the inner cooling water diffused from the inner cooling water are diffused into the catalytic tank 1 through the first connecting pipe 131 and the second connecting pipe 132, and hydrogen and oxygen react chemically under the action of the palladium catalyst 110 to produce water, and the chemical reaction reduces the oxygen content in the inner cooling water tank 2 and the catalytic tank 1, causing the dissolved oxygen in the inner cooling water tank 2 to continuously diffuse out, and continue to react with the leaked hydrogen under the action of the palladium catalyst 110, thereby ultimately achieving the purpose of reducing the dissolved oxygen content in the inner cooling water.

Claims

1. A method for reducing the amount of dissolved oxygen in cooling water of a generator, the device comprising an internal cooling water tank (2) and a catalyst tank (1); a catalyst frame (19) is arranged in the catalyst tank (1); a hanger (17) is arranged between the catalyst frame (19) and the inner wall of the catalyst tank (1); a connecting pipe is arranged between the catalyst tank (1) and the internal cooling water tank (2); the height of the catalyst tank (1) in the vertical direction is greater than the height of the internal cooling water tank (2) in the vertical direction; a catalyst (110) is arranged in the catalyst frame (19); the characteristics are: The catalytic tank (1) is arranged above the inner cooling water tank (2), and the hydrogen leaked from the stator chamber of the generator in the inner cooling water tank (2) and the inner cooling water dissolved oxygen diffused from the inner cooling water are diffused into the catalytic tank (1) through the connecting pipe. The hydrogen and oxygen react with each other under the action of the catalyst (110) to produce water, thereby reducing the oxygen content in the inner cooling water tank (2) and the catalytic tank (1), thereby reducing the dissolved oxygen content in the inner cooling water.

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