A system for preventing secondary filter screen blockage of condenser circulating water

Abstract

The present application relates to a kind of condenser circulating water secondary filter screen blocking prevention systems, including respectively being arranged in the water inlet end of condenser A, B side water supply branch pipe A, B side secondary filter screen, A side secondary filter screen A side blowdown pipe is connected with A side backwater branch pipe, and backwater valve water inlet end side;B side secondary filter screen B side blowdown pipe is connected with B side backwater branch pipe, and located on B side backwater branch pipe on backwater valve water inlet end side;The blowdown pipe of induced draft fan steam turbine condenser circulating water A, B side secondary filter screen is reformed, it is respectively connected to induced draft fan steam turbine condenser circulating water A, B side backwater valve before, so that the problem that induced draft fan steam turbine condenser circulating water A, B side secondary filter screen differential pressure high blowdown door is simultaneously opened can be effectively solved when mutual influence, the method has strong practicality and reliability.

Description

TECHNICAL FIELD

[0001] The present application relates to a kind of condenser circulating water secondary filter screen blocking prevention system, belong to storage technical field. BACKGROUND

[0002] With the development of power plant control technology in recent years, secondary filter screen control has been as an important control system in each power plant.The function is to purify water, keep condenser water chamber in clean state, avoid condenser titanium pipe blockage, and ensure the normal operation of condenser.

[0003] The existing induced draft fan turbine condenser circulating water A, B side secondary filter screen anti-blocking method is to control the rotation of A, B side secondary filter screen and the opening and closing of blow-off electric door by local PLC, and the blow-off pipes of A, B side secondary filter screen are connected to a blow-off pipe through blow-off electric door and then introduced into the induced draft fan turbine condenser B side circulating water return pipe and discharged into the sea.

[0004] During high tide, a large amount of sundries (seaweed, discarded fishing nets in the ocean, shellfish, etc.) will be brought into the induced draft fan circulating water secondary filter screen through the suction inlet of circulating water pump, causing high differential pressure of A, B side secondary filter screen, and the blow-off electric doors of PLC controlled secondary filter screen are opened at the same time to blow off, because the blow-off pipes of two secondary filter screens are finally connected to one blow-off pipe, causing the blow-off of A, B side secondary filter screen to affect each other, causing the sundries in the filter screen to be discharged slowly, the differential pressure of the filter screen to be gradually increased, and the filter screen to be blocked, the circulating water amount of induced draft fan turbine condenser to be reduced, and the output of generator set to be forced to be reduced, and in severe cases, the circulating water of induced draft fan turbine condenser will be interrupted, causing the unit to be shut down unexpectedly.

[0005] If the blow-off electric door of secondary filter screen is damaged and needs to be replaced during the operation of the unit, the induced draft fan turbine will be forced to shut down and the circulating water system of induced draft fan turbine condenser will be shut down due to the inability to reliably isolate the system. SUMMARY

[0006] The purpose of the present application is to provide a condenser circulating water secondary filter screen blocking prevention system to solve the problem of poor blow-off of A, B side secondary filter screen of fan turbine condenser circulating water in the background technology.

[0007] The technical scheme of the present application is as follows:

[0008] A condenser circulating water secondary filter screen blocking prevention system, comprising:

[0009] A side secondary filter screen arranged on A side water supply branch pipe at the water inlet end of condenser, and B side secondary filter screen arranged on B side water supply branch pipe at the water inlet end of condenser;

[0010] The A-side blow-off pipe of the A-side secondary filter is connected with an A-side backwater branch pipe arranged at the backwater end of the condenser, and is located at the inlet water end side of the backwater valve on the A-side backwater branch pipe.

[0011] The B-side blow-off pipe of the B-side secondary filter is connected with a B-side backwater branch pipe arranged at the backwater end of the condenser, and is located at the inlet water end side of the backwater valve on the B-side backwater branch pipe.

[0012] Preferably, the A-side water supply branch pipe and the B-side water supply branch pipe are connected in parallel with a water supply pipe, and the inlet water end of the water supply pipe is connected with the outside sea.

[0013] Preferably, the A-side backwater branch pipe and the B-side backwater branch pipe are connected in parallel with a backwater pipe, and the outlet water end of the backwater pipe is connected with the outside sea.

[0014] Preferably, an A-side blow-off valve is arranged on the A-side blow-off pipe.

[0015] Preferably, a B-side blow-off valve is arranged on the B-side blow-off pipe.

[0016] The present application has the following beneficial effects:

[0017] The blow-off pipes of the A-side and B-side secondary filters of the induced draft fan turbine condenser circulating water are reformed and connected to the A-side and B-side backwater valves of the induced draft fan turbine condenser circulating water respectively, so that the problem of mutual influence of the A-side and B-side secondary filters of the induced draft fan turbine condenser circulating water when the high blow-off valves are opened simultaneously can be effectively solved, and the method has strong practicability and reliability. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 The figure is a schematic diagram of the system before the present application is reformed;

[0019] Figure 2 The figure is a schematic diagram of the system after the present application is reformed.

[0020] 1, condenser; 2, water supply pipe; 21, A-side water supply branch pipe; 22, B-side water supply branch pipe; 3, backwater pipe; 31, A-side backwater branch pipe; 32, B-side backwater branch pipe; 4, A-side secondary filter; 41, A-side blow-off pipe; 5, B-side secondary filter; 51, B-side blow-off pipe; 6, backwater valve; 7, A-side blow-off valve; 8, B-side blow-off valve; 9, inlet water valve. DETAILED DESCRIPTION

[0021] The present application will be described in detail below in combination with the drawings and specific embodiments.

[0022] Example 1: the system before the present application is reformed:

[0023] As Figure 1As shown, the A-side water supply branch pipe 21 and the B-side water supply branch pipe 22 are connected in parallel and connected to the outlet end of the water supply pipe 2. The outlet end of the A-side water supply branch pipe 21 is connected to the A-side water inlet end of the front water chamber of the condenser 1, and the outlet end of the B-side water supply branch pipe 22 is connected to the B-side water inlet end of the front water chamber of the condenser 1. Corresponding water inlet valves 9 are installed on both the A-side water supply branch pipe 21 and the B-side water supply branch pipe 22. The A-side secondary filter screen 4 is installed on the A-side water supply branch pipe 21, and the B-side secondary filter screen 5 is installed on the B-side water supply branch pipe 22.

[0024] The A-side outlet of the condenser 1 front water chamber is connected to the A-side return water branch pipe 31, and the B-side outlet of the condenser 1 front water chamber is connected to the B-side return water branch pipe 32. The A-side return water branch pipe 31 and the B-side return water branch pipe 32 are arranged in parallel and connected to the return water pipe 3, which discharges to the sea. Corresponding return water valves 6 are installed on both the A-side return water branch pipe 31 and the B-side return water branch pipe 32.

[0025] The A-side drain pipe 41 of the secondary filter 4 on side A and the B-side drain pipe 51 of the secondary filter 5 on side B are connected in parallel and then pass through another drain pipe. Figure 1 The dotted line section is connected to the A-side return water branch pipe 31 / B-side return water branch pipe 32 and is located on the side of the outlet end of the return water valve 6; the A-side drain valve 7 is installed on the A-side drain pipe 41 and the B-side drain valve 8 is installed on the B-side drain pipe 51.

[0026] The return water valve 6, the A-side drain valve 7 and the B-side drain valve 8, and the inlet valve 9 are all electric valves.

[0027] Since both the water supply pipe 2 and the return pipe 3 are connected to the sea, during high tide, the suction inlet of the circulating water pump (not shown in the attached diagram) will carry in a large amount of debris (seaweed, discarded fishing nets, shellfish, etc.) into the secondary filter screen 4 on side A and the secondary filter screen 5 on side B, causing a high differential pressure between the secondary filters on sides A and B. The PLC controls the drain valve 7 on side A and the drain valve 8 on side B to open simultaneously for drainage. Since the drain pipe 41 on side A and the drain pipe 51 on side B eventually converge into one drain pipe, the drain pipe 41 on side A and the drain pipe 51 on side B affect each other, causing poor drainage of debris in the secondary filters on side A and side B and the secondary filter screen 5. The differential pressure of the filters gradually increases and becomes blocked, reducing the amount of circulating water entering the condenser 1, forcing a reduction in the output of the generator unit. In severe cases, it can cause the circulating water of the condenser 1 to be interrupted and the unit to shut down unplanned.

[0028] Example 2: This is a modified system, an improvement upon Example 1. The differences are as follows:

[0029] The A-side drain pipe 41 of the secondary filter 4 on side A is connected to the A-side return water branch pipe 31 and is located on the side of the inlet end of the return water valve 6 on the A-side return water branch pipe 31.

[0030] The B-side blowdown pipe 51 of the B-side secondary filter screen 5 is connected with the B-side water return branch pipe 32, and is located on the inlet water end side of the water return valve 6 on the B-side water return branch pipe 32.

[0031] Thus, the problem of mutual influence of the high differential pressure blowdown valves of the A-side and B-side secondary filter screens of the condenser 1 when simultaneously opened can be effectively solved, and the reliability of the system can be improved; when any one of the A-side blowdown valve 7 and the B-side blowdown valve 8 is damaged, only the half side of the condenser 1 circulating water needs to be isolated, and the blowdown valve can be replaced on line, without stopping the operation of the induced draft fan, the steam turbine and the condenser circulating water system.

[0032] The above is only an embodiment of the present application, and does not limit the patent scope of the present application, and any equivalent structure or equivalent flow transformation using the content of the specification and the drawings, or direct or indirect application in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A system for preventing secondary filter screen blockage of condenser circulating water, comprising: A-side secondary filter screen (4) arranged on A-side water supply branch pipe (21) of condenser (1) water inlet end, and B-side secondary filter screen (5) arranged on B-side water supply branch pipe (22) of condenser (1) water inlet end; characterized in that: A-side blowdown pipe (41) of the A-side secondary filter screen (4) is connected with A-side return water branch pipe (31) arranged at the return water end of the condenser (1), and is located at the inlet end side of the return water valve (6) on the A-side return water branch pipe (31); B-side blowdown pipe (51) of the B-side secondary filter screen (5) is connected with B-side return water branch pipe (32) arranged at the return water end of the condenser (1), and is located at the inlet end side of the return water valve (6) on the B-side return water branch pipe (32); A-side water supply branch pipe (21) and B-side water supply branch pipe (22) are connected in parallel with water supply pipe (2), and the inlet end of the water supply pipe (2) is connected with the outside sea; A-side return water branch pipe (31) and B-side return water branch pipe (32) are connected in parallel with return water pipe (3), and the outlet end of the return water pipe (3) is connected with the outside sea; A-side blowdown valve (7) is installed on the A-side blowdown pipe (41); B-side blowdown valve (8) is installed on the B-side blowdown pipe (51).

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