A mixed flow turbine generator set and a water filling method for a technical water supply system

Abstract

The present invention provides a method for filling a mixed flow turbine generator set and a technical water supply system, comprising the following steps: step 1, preparation before filling the tailwater gate lift gate with water; step 2, filling the technical water supply drainage pipeline with water; step 3, filling the pressure steel pipe and the volute with water; step 4, adjusting the pressure of the pressure reducing valve and filling each load of the technical water supply system with water. It can greatly save the time for filling the unit and the technical water supply system with water after the unit is overhauled, and quickly restore the generator set to the standby state; it can effectively avoid the phenomenon that the valve cannot be opened due to the pressure buildup during the water filling process of the giant unit; the pipeline is vented more fully, greatly reducing the impact of water hammer on the coolers and related pipelines in various parts of the unit; it can reduce the impact of high pressure on the pipeline and various coolers during the pressure adjustment process of the technical water supply pressure reducing valve.

Description

Technical Field

[0001] The invention relates to the technical field of a hydraulic turbine generator set and technical water supply, and in particular to a water filling method of a mixed flow hydraulic turbine generator set and a technical water supply system. Background Art

[0002] The Three Gorges Underground Power Station is equipped with 26 units of 700MW large-scale mixed-flow turbine generators, using a dam-back type plant with a standard water level drop of 85m. Under normal power generation conditions, the upstream water flows through the water inlet fast gate arranged on the top of the dam, the water diversion pressure steel pipe, enters the turbine volute, passes through the guide vanes, and then works for the turbine, and then is discharged to the downstream through the tailwater pipe.

[0003] The technical water supply system serves as the cooling system for the entire hydro-turbine generator set. Its cooling water intake is arranged in the turbine volute. The cooling water takes away the heat generated during the operation of the unit and is discharged into the downstream tail water.

[0004] When the unit is shut down for maintenance, the unit guide vanes are fully closed, the water inlet quick gate and the tailwater gate at the tailwater pipe outlet are closed; the accumulated water in the unit is drained by a water pump before the unit is overhauled. After the maintenance is completed, the unit and the technical water supply system need to be filled with water. How to complete the water filling operation quickly and safely is an important technical issue.

[0005] The existing water filling operation adopts the method of filling water step by step according to the direction of water flow. The existing water filling method has the problems of long filling time, insufficient pipeline exhaust, and a large impact of water hammer on the pipeline during water filling. It does not consider the impact of valve leakage or pressure adjustment of the pressure reducing valve on the coolers of each unit. Summary of the invention

[0006] In order to solve the above technical problems, the present invention provides a water filling method for a mixed flow turbine generator set and a technical water supply system. This water filling method can greatly save the time for filling the unit and the technical water supply system after the unit is overhauled, and quickly restore the generator set to a standby state; it can effectively avoid the phenomenon that the valve cannot be opened due to pressure buildup during the water filling process of a giant unit; this method can fully vent the pipeline and greatly reduce the impact of water hammer on the coolers and related pipelines in various parts of the unit; this method can reduce the impact of high pressure on the pipeline and various coolers during the pressure adjustment process of the technical water supply pressure reducing valve.

[0007] In order to realize the above technical features, the object of the present invention is achieved as follows: a method for filling a mixed flow turbine generator set and a technical water supply system, comprising the following steps:

[0008] Step 1, preparation before filling the tailwater gate lift gate with water;

[0009] Step 2, filling the technical water supply and drainage pipeline with water;

[0010] Step 3, filling the pressure steel pipe and volute with water;

[0011] Step 4, adjust the pressure reducing valve pressure and fill each load of the technical water supply system with water.

[0012] The specific steps of step 1 are:

[0013] Step 1.1: The relevant work tickets for unit maintenance have been cancelled, and the tailwater pipe and technical water supply system users are ready for water filling;

[0014] Step 1.2, fully open the water outlet electric valve of the water supply filter of the unit;

[0015] Step 1.3, completely shut down the water inlet electric valve of the water supply filter of the unit;

[0016] Step 1.4, fully open the technical water supply system pressure reducing valve imported electric valve;

[0017] Step 1.5, fully close the manual valve at the outlet of the pressure reducing valve of the technical water supply system;

[0018] Step 1.6, check that the inlet and outlet valves of each technical water supply user are fully closed;

[0019] Step 1.7, lift the tailwater gate and fill it with water;

[0020] Step 1.8, after the tailwater gate is lifted, fill the technical water supply pipeline with water through the technical water supply system drain valve to discharge the pipeline gas and maintain the same pressure as the tailwater. During the filling process, supervision and on-site inspection should be strengthened.

[0021] The users in step 1.1 are the various coolers of the hydro-generator set.

[0022] The specific steps of step 2 are:

[0023] Step 2.1, fully open the main drain valve of the technical water supply system of the unit;

[0024] Step 2.2, fully open the main sewage valve of the technical water supply filter of the unit;

[0025] Step 2.3, fully open the main line pressure relief / maintaining valve of the unit;

[0026] Step 2.4, fully open the technical water supply forward drainage electric valve and the technical water supply reverse drainage electric valve;

[0027] Step 2.5, fully open the technical water supply forward water supply electric valve and the technical water supply reverse water supply electric valve;

[0028] Step 2.6: During the water filling process, check all pipes for leaks;

[0029] Step 2.7, before the rapid door lift gate fills the pressure steel pipe with water, the technical water supply main water inlet electric valve and the technical water supply main water inlet manual valve should be opened appropriately to prevent the valve from being pressurized.

[0030] The specific steps of step 3 are:

[0031] Step 3.1, properly open the technical water supply main water inlet manual valve to 5%-10% opening, and fully open the technical water supply main electric valve;

[0032] Step 3.2, open the rapid door pressure relief valve, and fill the pressure steel pipe and volute with water until the pressure is equalized;

[0033] Step 3.3: During the water filling period, closely monitor the pressure, flow rate of each part and the access doors and disc valve operation corridors;

[0034] Step 3.4, check that the water supply pressure of each technical water supply pipeline does not exceed the specified value. If it exceeds the pressure, stop filling water immediately.

[0035] The specific steps of step 4 are:

[0036] Step 4.1, adjust the pressure of the pressure reducing valve and the pressure relief and pressure holding valve;

[0037] Step 4.2, fully open the technical water supply main water inlet manual valve;

[0038] Step 4.3, fully open the water inlet electric valve of the water filter of the unit;

[0039] Step 4.4, fully open the manual valve at the outlet of the pressure reducing valve of the technical water supply system;

[0040] Step 4.5, fully close the technical water supply reverse water supply electric valve;

[0041] Step 4.6, fully close the technical water supply reverse drainage electric valve;

[0042] Step 4.7, fully open the forward water supply and drainage valves of each user;

[0043] Step 4.8, fully open the forward water supply valves of each user.

[0044] In step 4, special attention should be paid to the impact of the unit's forward and reverse water supply modes on the user's cooler. The cooler's water outlet valve should be opened first, and then the cooler's water inlet valve should be opened to prevent the cooler from being damaged by pressure buildup.

[0045] The main drain valve of the unit's technical water supply system, the main sewage valve of the unit's technical water supply filter and the unit's main line pressure relief / pressure holding valve are all connected to the tailwater main drain pipe.

[0046] The present invention has beneficial effects:

[0047] 1. The method of the present invention can greatly save the time for filling the unit and the technical water supply system with water after the unit is overhauled, and the generator set can be quickly restored to the standby state; it can effectively avoid the phenomenon that the valve cannot be opened due to pressure buildup during the water filling process of the giant unit; this patent is more sufficient for pipeline exhaust, greatly reducing the impact of water hammer on the coolers and related pipelines in various parts of the unit; this patent can reduce the impact of high pressure on the pipeline and various coolers during the pressure adjustment process of the technical water supply pressure reducing valve. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0049] Figure 1 It is a schematic diagram of the mixed flow turbine generator set and technical water supply principle of the present invention.

[0050] Figure 2 It is a diagram of the mixed flow turbine generator set and the technical water supply system of the present invention.

[0051] In the figure: technical water supply main inlet manual valve 1, technical water supply main electric valve 2, unit technical water supply filter inlet electric valve 3, unit technical water supply filter outlet electric valve 4, technical water supply system pressure reducing valve inlet electric valve 5, technical water supply system pressure reducing valve outlet manual valve 6, technical water supply forward drainage electric valve 7, technical water supply reverse drainage electric valve 8, technical water supply forward water supply electric valve 9, unit technical water supply system main drainage valve 10, each user's forward water supply valve 11, each user's forward water supply drainage valve 12, unit main line pressure relief / maintaining valve 13, unit technical water supply filter sewage main valve 14, technical water supply reverse water supply electric valve 15. DETAILED DESCRIPTION

[0052] The embodiments of the present invention are further described below in conjunction with the accompanying drawings.

[0053] See also Figure 1-2 , a method for filling a mixed flow turbine generator set and a technical water supply system, comprising the following steps:

[0054] Step 1, preparation before filling the tailwater gate lift gate with water;

[0055] Step 1.1: The relevant work tickets for unit maintenance have been cancelled, and the tailwater pipe and technical water supply system users are ready for water filling;

[0056] Step 1.2, fully open the water outlet electric valve 4 of the water supply filter of the unit;

[0057] Step 1.3, fully close the water inlet electric valve 3 of the water supply filter of the unit;

[0058] Step 1.4, fully open the technical water supply system pressure reducing valve inlet electric valve 5;

[0059] Step 1.5, fully close the outlet manual valve 6 of the pressure reducing valve of the technical water supply system;

[0060] Step 1.6, check that the inlet and outlet valves of each technical water supply user are fully closed;

[0061] Step 1.7, lift the tailwater gate and fill it with water;

[0062] Step 1.8, after the tailwater gate is lifted, fill the technical water supply pipeline with water through the technical water supply system drain valve to discharge the pipeline gas and maintain the same pressure as the tailwater. During the filling process, supervision and on-site inspection should be strengthened.

[0063] Step 2, filling the technical water supply and drainage pipeline with water;

[0064] Step 2.1, fully open the main drain valve 10 of the technical water supply system of the unit;

[0065] Step 2.2, fully open the unit technical water supply filter sewage main valve 14;

[0066] Step 2.3, fully open the main line pressure relief / maintaining valve 13 of the unit;

[0067] Step 2.4, fully open the technical water supply forward drainage electric valve 7 and the technical water supply reverse drainage electric valve 8;

[0068] Step 2.5, fully open the technical water supply forward water supply electric valve 9 and the technical water supply reverse water supply electric valve 15;

[0069] Step 2.6: During the water filling process, check all pipes for leaks;

[0070] Step 2.7, before the rapid door lift gate fills the pressure steel pipe with water, the technical water supply main water inlet electric valve and the technical water supply main water inlet manual valve 1 should be opened appropriately to prevent the valve from being pressurized.

[0071] Step 3, filling the pressure steel pipe and volute with water;

[0072] Step 3.1, appropriately open the technical water supply main water inlet manual valve 1 to 5%-10% opening, and fully open the technical water supply main electric valve 2;

[0073] Step 3.2, open the rapid door pressure relief valve, and fill the pressure steel pipe and volute with water until the pressure is equalized;

[0074] Step 3.3: During the water filling period, closely monitor the pressure, flow rate of each part and the access doors and disc valve operation corridors;

[0075] Step 3.4, check that the water supply pressure of each technical water supply pipeline does not exceed the specified value. If it exceeds the pressure, stop filling water immediately.

[0076] Step 4, adjust the pressure reducing valve pressure and fill each load of the technical water supply system with water.

[0077] Step 4.1, adjust the pressure of the pressure reducing valve and the pressure relief and pressure holding valve;

[0078] Step 4.2, fully open the technical water supply main water inlet manual valve 1;

[0079] Step 4.3, fully open the water inlet electric valve 3 of the water filter of the unit technical water supply;

[0080] Step 4.4, fully open the outlet manual valve 6 of the pressure reducing valve of the technical water supply system;

[0081] Step 4.5, fully close the technical water supply reverse water supply electric valve 15;

[0082] Step 4.6, fully close the technical water supply reverse drainage electric valve 8;

[0083] Step 4.7, fully open the forward water supply and drainage valves 12 of each user;

[0084] Step 4.8, fully open the forward water supply valve 11 of each user.

[0085] Furthermore, the users in step 1.1 are the coolers of the hydro-generator set.

[0086] Furthermore, in step 4, special attention should be paid to the impact of the forward and reverse water supply modes of the unit on the user's cooler. The cooler outlet valve should be opened first, and then the cooler inlet valve should be opened to prevent the cooler from being damaged by pressure buildup.

[0087] Furthermore, the main drain valve 10 of the unit's technical water supply system, the main sewage valve 14 of the unit's technical water supply filter and the pressure relief / maintaining valve 13 of the unit's main line are all connected to the main tailwater drain pipe.

Claims

1. A method for filling a water supply system of a mixed flow turbine generator set, characterized in that: The following steps are involved: Step 1, preparation before filling the tailwater gate lift gate with water; Step 2, filling the technical water supply and drainage pipeline with water; Step 3, filling the pressure steel pipe and volute with water; Step 4, adjusting the pressure of the pressure reducing valve and filling each load of the technical water supply system with water; The specific steps of step 1 are: Step 1.1: The relevant work tickets for unit maintenance have been cancelled, and the tailwater pipe and technical water supply system users are ready for water filling; Step 1.2, fully open the water outlet electric valve (4) of the water supply filter of the unit; Step 1.3, fully close the water inlet electric valve (3) of the water supply filter of the unit; Step 1.4, fully open the inlet electric valve (5) of the pressure reducing valve of the water supply system; Step 1.5, fully close the manual valve (6) at the outlet of the pressure reducing valve of the technical water supply system; Step 1.6, check that the inlet and outlet valves of each technical water supply user are fully closed; Step 1.7, lift the tailwater gate and fill it with water; Step 1.8, after the tailwater gate is lifted, water is filled into the technical water supply pipeline through the technical water supply system drain valve to discharge the gas in the pipeline and maintain the same pressure as the tailwater. During the water filling process, monitoring and on-site inspection should be strengthened; The specific steps of step 2 are: Step 2.1, fully open the main drain valve (10) of the technical water supply system of the unit; Step 2.2, fully open the main sewage valve (14) of the technical water supply filter of the unit; Step 2.3, fully open the main line pressure relief and pressure holding valve (13) of the unit; Step 2.4, fully open the technical water supply forward drainage electric valve (7) and the technical water supply reverse drainage electric valve (8); Step 2.5, fully open the technical water supply forward water supply electric valve (9) and the technical water supply reverse water supply electric valve (15); Step 2.6: During the water filling process, check all pipes for leaks; Step 2.7, before the rapid door lift gate fills the pressure steel pipe with water, the technical water supply main water inlet electric valve and the technical water supply main water inlet manual valve (1) should be opened appropriately to prevent the valve from being blocked; The specific steps of step 3 are: Step 3.1, appropriately open the technical water supply main water inlet manual valve (1) to 5%-10% opening, and fully open the technical water supply main electric valve (2); Step 3.2, open the rapid door pressure relief valve, and fill the pressure steel pipe and volute with water until the pressure is equalized; Step 3.3: During the water filling period, closely monitor the pressure, flow rate of each part and the access doors and disc valve operation corridors; Step 3.4, check that the water supply pressure of each technical water supply pipeline does not exceed the specified value. If it exceeds the pressure, stop filling water immediately; The unit technical water supply system main drain valve (10), the unit technical water supply filter sewage main drain valve (14) and the unit main line pressure relief and pressure holding valve (13) are all connected to the tailwater main drain pipe.

2. The method for filling a water supply system of a mixed flow turbine generator set according to claim 1, characterized in that: The users in step 1.1 are the various coolers of the hydro-generator set.

3. The method for filling a water supply system of a mixed flow turbine generator set according to claim 1, characterized in that: The specific steps of step 4 are: Step 4.1, adjust the pressure of the pressure reducing valve and the pressure relief and pressure holding valve; Step 4.2, fully open the technical water supply main water inlet manual valve (1); Step 4.3, fully open the water inlet electric valve (3) of the water filter of the unit technical water supply; Step 4.4, fully open the outlet manual valve (6) of the pressure reducing valve of the technical water supply system; Step 4.5, fully close the technical water supply reverse water supply electric valve (15); Step 4.6, fully close the water supply reverse drainage electric valve (8); Step 4.7, fully open the forward water supply and drainage valves (12) of each user; Step 4.8, fully open the forward water supply valve (11) of each user.

4. The method for filling a water supply system of a mixed flow turbine generator set according to claim 1, characterized in that: In step 4, special attention should be paid to the impact of the unit's forward and reverse water supply modes on the user's cooler. The cooler's water outlet valve should be opened first, and then the cooler's water inlet valve should be opened to prevent the cooler from being damaged by pressure buildup.

Images