Complete set of test equipment for forced air supply of giant water-turbine generator set

Abstract

The forced air supply equipment comprises an air compressor, an air supply pipeline, an air storage tank, a first isolating valve, a first pressure gauge, a check valve, a second isolating valve, a second pressure gauge, a second check valve, a third isolating valve, a third pressure gauge, a fourth pressure gauge and a flow meter, and further comprises an air supply device for controlling the first isolating valve, the second pressure gauge, the third check valve, the third isolating valve, the third pressure gauge, the fourth pressure gauge and the flow meter. The control mechanism comprises a PLC (Programmable Logic Controller), an acceleration sensor and a high-frequency response sensor, the signal input end of the PLC is connected with a first pressure gauge, a second pressure gauge, a third pressure gauge, a fourth pressure gauge and a flow meter, the acceleration sensor and the high-frequency response sensor are connected with the first pressure gauge, the second pressure gauge, the third pressure gauge and the fourth pressure gauge, and the flow meter is connected with the second pressure gauge. According to the method, automatic gas supplementing of the part to be subjected to gas supplementing is achieved, the cavitation phenomenon is accurately restrained, and meanwhile through a trend prediction and weight distribution mechanism, the stability and economical efficiency of the gas supplementing system are remarkably improved.

Description

Technical Field

[0001] This invention relates to the field of hydro turbine technology, and more particularly to a complete set of test equipment for forced air injection of a giant hydro turbine generator set. Background Technology

[0002] Due to limitations in early design depth and model testing, large-scale hydro-turbine generator units often experience pressure pulsation and cavitation-induced erosion during actual operation. These phenomena can be mitigated or eliminated by supplementing air at different locations within the unit. For large-scale hydro-turbine generator units, the preliminary design stage typically considers reserving air inlets for locations such as the main shaft, top cover, seat ring, and tailrace cone. The low-pressure air system in the auxiliary equipment of the hydraulic unit also includes a certain amount of air supply margin. However, in actual operation, these are often not actually put into operation. When abnormal operating conditions occur, a temporary air supply system needs to be installed for testing. Summary of the Invention

[0003] To solve the above-mentioned technical problems, the present invention provides a complete set of test equipment for forced air replenishment of giant hydro-generator sets.

[0004] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A forced air supply device for a giant hydro-generator unit includes an air compressor and an air supply pipeline. The air supply pipeline includes a main pipe connected to the exhaust end of the air compressor and multiple branch pipes that are respectively connected to the exhaust end of the main pipe and connected to the part of the hydro-generator unit to be supplied with air. Multiple air storage tanks are provided on the main pipe. Along the airflow direction, the branch pipe is sequentially equipped with a first isolation valve, a first pressure gauge, and a check valve. The main pipe, located between two adjacent air tanks, is equipped with a second isolation valve, a second pressure gauge, and a second check valve along the airflow direction. The end of the main pipe used to connect to the air compressor is equipped with a third isolation valve and a third pressure gauge, and the end used to connect to the branch pipe is equipped with a fourth pressure gauge and a flow meter. It also includes a control mechanism for controlling the operating status of each first isolation valve, as well as the second isolation valve, the third isolation valve, and the air compressor.

[0005] Preferably, the gas storage tank is equipped with an exhaust pipe, and the exhaust pipe is equipped with a safety valve.

[0006] Preferably, the control mechanism includes a PLC controller, an acceleration sensor arranged at the air supply point for assessing the degree of cavitation, and a high-frequency response sensor for capturing transient pressure peaks. The signal input terminals of the PLC controller are connected to the first pressure gauge, the second pressure gauge, the third pressure gauge, the fourth pressure gauge, the flow meter, the acceleration sensor, and the high-frequency response sensor. The signal output terminals of the PLC controller are connected to the air compressor and each of the first and second isolation valves. By controlling the opening and closing of the valves, air supply is provided to the air supply points of the hydro-generator unit.

[0007] Preferably, the number and specifications of the branch pipes correspond to the number and specifications of the air inlets of the parts to be supplied with air in the turbine generator set, and the parts to be supplied with air include at least the main shaft, top cover, seat ring and tailrace cone pipe.

[0008] Preferably, both the main pipe and branch pipes are made of corrosion-resistant materials, and drain valves and safety valves are installed at key nodes.

[0009] Preferably, the air compressor is a variable frequency air compressor, which can automatically adjust the air supply pressure and flow according to the unit's operating status, and can also monitor the unit's operating temperature, power, cooling water temperature, lubricating oil level, etc.

[0010] Compared with the prior art, the present invention has the following beneficial effects: This invention achieves automatic air replenishment of the turbine by detecting pressure pulsations and assessing cavitation levels at the air replenishment points, and by using PLC to automatically control the start and stop of the air compressor and various isolation valves. This enables precise suppression of cavitation and significantly improves the stability and economy of the air replenishment system through trend prediction and weight allocation mechanisms. Attached Figure Description

[0011] Figure 1 This is a system schematic diagram of the present invention; Figure 2 This is a block diagram of the signal transmission of the control mechanism of the present invention.

[0012] Attached image labels: 1. Air compressor; 2. Air supply line; 201. Main pipe; 202. Branch pipe; 3. Air tank; 301. Exhaust pipe; 4. First isolation valve; 5. First pressure gauge; 6. Check valve; 7. Second isolation valve; 8. Second pressure gauge; 9. Second check valve; 10. Third isolation valve; 11. Third pressure gauge; 12. Fourth pressure gauge; 13. Flow meter; 14. Safety valve. Detailed Implementation

[0013] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the embodiments and accompanying drawings. The illustrative embodiments and descriptions of the present invention are only used to explain the present invention and are not intended to limit the present invention.

[0014] Example 1 like Figure 1The forced air supply equipment for a giant hydro-generator set is characterized by comprising an air compressor 1 and an air supply pipeline 2. The air supply pipeline 2 includes a main pipe 201 connected to the exhaust end of the air compressor 1, and multiple branch pipes 202 respectively connected to the exhaust end of the main pipe 201 and connected to the part of the hydro-generator set to be supplied with air. The main pipe 201 is provided with multiple air storage tanks 3. Along the airflow direction, the branch pipes 202 are sequentially provided with a first isolation valve 4, a first pressure gauge 5, and a check valve 6. The part of the main pipe 201 between two adjacent air storage tanks is provided with a second isolation valve 7, a second pressure gauge 8, and a second check valve 9 along the airflow direction. The end of the main pipe 201 used to connect to the air compressor 1 is provided with a third isolation valve 10 and a third pressure gauge 11, and the end used to connect to the branch pipes 202 is provided with a fourth pressure gauge 12 and a flow meter 13. It also includes a control mechanism for controlling the operating status of each of the first isolation valves 4, the second isolation valves 7, the third isolation valves 10, and the air compressor 1. Air compressor 1 outputs compressed air to air storage tank 3 through main pipe 201. Air storage tank 3 then supplies air to the parts of the hydro-generator unit that require air replenishment via branch pipe 202 to achieve forced air replenishment to the hydro-generator unit. Specifically, the selection of the aforementioned air storage tank 3 mainly considers transportation, hoisting, equipment layout, rated pressure, and effective capacity. Giant hydro-generator units require a large amount of air replenishment, so it is advisable to have two or more air storage tanks. The pressure and capacity of the air storage tanks should be selected with reference to the hydraulic machinery design manual.

[0015] As a preferred embodiment of the above, the gas storage tank 3 is provided with an exhaust pipe 301, and the exhaust pipe 301 is provided with a safety valve 14.

[0016] As a preferred embodiment of the above, the number of branch pipes 202 corresponds to the number of parts of the turbine generator set that need to be replenished with air, including the main shaft, top cover, seat ring and tailrace cone.

[0017] As a preferred embodiment of the above, both the main pipe 201 and the branch pipe 202 are made of corrosion-resistant materials, and drain valves and safety valves are installed at key nodes.

[0018] As a preferred embodiment of the above, air compressor 1 is a variable frequency air compressor, which can automatically adjust the air supply pressure and flow rate according to the unit's operating status. The selection of the air compressor mainly considers transportation, hoisting, power load, air supply pressure, air volume balance with the air storage tank, and air supply displacement conditions. The air supply pressure needs to consider the maximum pressure at the air replenishment location and the air supply pipeline loss, and the air supply displacement needs to consider the maximum air supply volume during the air replenishment test.

[0019] The aforementioned control mechanisms, such as Figure 2As shown in the figure, it includes a PLC controller, an acceleration sensor arranged at the part to be supplemented with air for evaluating the degree of cavitation, and a high-frequency response sensor for capturing transient pressure peaks. The signal input end of the PLC controller is signal-connected to the first pressure gauge 5, the second pressure gauge 8, the third pressure gauge 11, the fourth pressure gauge 12, the flowmeter 13, the acceleration sensor and the high-frequency response sensor. The signal output end of the PLC controller is connected to the start and stop of the air compressor 1 and each first isolation valve 4 and second isolation valve 7 to supplement air to the part to be supplemented with air of the hydro-generator unit. The specific control steps are as follows: 1. Preset pressure thresholds (Pmin = 0.6 MPa, Pmax = 0.8 MPa), flow target value (5.0 m³ / min), and air supply point weights (30% for the main shaft, 20% for the top cover, 25% for the stay ring, 25% for the draft tube cone) in the PLC controller 2. Read the data of each sensor according to the period, including the main pipe 201 pressure (P1): the outlet pressure of the air compressor 1, the branch pipe 202 pressure (P2): the pressure in the middle section of the air supply pipeline, the air supply point pressure (P3): the pressure in the cavitation area of the unit, and the flow rate (F1): the actual air supply flow rate Data verification: Eliminate outliers (such as pressure sudden change exceeding ±20% or flow rate being negative) Trend calculation: Calculate the pressure change rate (dP / dt) based on the recent 3 pressure sampling points 3. Air compressor control logic Starting conditions (start when any one is met): P1 < P_min (insufficient main pipe pressure) dP / dt < -0.05 MPa / s (rapid pressure drop) Stopping conditions (stop when any one is met): P1 > P_max (excessive main pipe pressure) dP / dt > +0.05 MPa / s (rapid pressure rise) Status maintenance: When the pressure is in the interval (P_min, P_max) and the trend is stable, maintain the current air compressor status 4. Valve control strategy Emergency air supply mode (P3 < 0.6 MPa): Open all air supply point valves (main shaft / top cover / stay ring / draft tube cone) Flow regulation mode: Calculate the flow deviation: ΔF = |F1 - 5.0| m³ / min Allocate valve openings according to weights: If ΔF > 0.5 m³ / min: Open the valves with weights > 20% (main shaft / stay ring / draft tube cone) If ΔF ≤ 0.5m³ / min: Fully open all valves. Safety Protection: When P2 > 0.8 MPa, immediately close all valves. When an abnormal temperature is detected, an emergency shutdown is triggered. 5. Alarms and Diagnostics Pressure Anomaly Alarm: P1 < 0.48 MPa (Low pressure alarm) P1>0.96MPa (High-voltage alarm) P3 < 0.5 MPa (Insufficient gas supply alarm) Traffic anomaly alarm: F1<3.0m³ / min or F1>7.0m³ / min This control scheme achieves precise suppression of cavitation in giant hydro-generator units through multi-parameter fusion decision-making. At the same time, it significantly improves the stability and economy of the air replenishment system through trend prediction and weight allocation mechanisms.

[0020] Of course, the present invention may have many other embodiments. Without departing from the spirit and essence of the present invention, those skilled in the art can make various corresponding changes and modifications according to the present invention, but these corresponding changes and modifications should all fall within the protection scope of the appended claims.

Claims

1. A complete test equipment for forced air supply of a giant hydroelectric generating unit, characterized in that, The air compressor (1) and the air supplement pipeline (2) are included, the air supplement pipeline (2) includes the main pipe (201) connected with the exhaust end of the air compressor (1), and the multiple branch pipes (202) connected with the exhaust end of the main pipe (201) and the air supplement parts of the hydroelectric generator set, multiple air tanks (3) are arranged on the main pipe (201); In the airflow direction, the first cut-off valve (4), the first pressure gauge (5) and the check valve (6) are arranged on the branch pipe (202) in sequence, the second cut-off valve (7), the second pressure gauge (8) and the second check valve (9) are arranged on the part of the main pipe (201) between the adjacent two air tanks (3), the third cut-off valve (10) and the third pressure gauge (11) are arranged on the end of the main pipe (201) connected with the air compressor (1), the fourth pressure gauge (12) and the flowmeter (13) are arranged on the end of the main pipe (201) connected with the branch pipe (202), and the control mechanism for controlling the running state of the first cut-off valve (4), the second cut-off valve (7), the third cut-off valve (10) and the air compressor (1) is further included.

2. The complete forced air makeup test equipment for giant hydro-generator unit according to claim 1, characterized in that, The air tank (3) is provided with the exhaust pipe (301), and the safety valve (14) is arranged on the exhaust pipe (301).

3. The complete forced air supply test equipment for giant hydro-generator unit set according to any one of claims 1-2, characterized in that, The control mechanism includes the PLC controller, the acceleration sensor arranged on the air supplement part for evaluating the cavitation erosion degree and the high-frequency response sensor for capturing the transient pressure peak, the signal input end of the PLC controller is connected with the first pressure gauge (5), the second pressure gauge (8), the third pressure gauge (11), the fourth pressure gauge (12), the flowmeter (13), the acceleration sensor and the high-frequency response sensor, and the signal output end of the PLC controller is connected with the air compressor (1) and the start-stop of the first cut-off valve (4) and the second cut-off valve (7).

4. The complete test equipment for forced air supplement of a giant hydro-generator unit according to claim 3, characterized in that, The number and specification of the branch pipe (202) correspond to the number and specification of the air inlet of the air supplement part of the hydroelectric generator set, and the air supplement part at least includes the main shaft, the top cover, the seat ring and the draft tube.

5. The complete test equipment for forced air supplement of a giant hydro-generator unit according to claim 4, characterized in that, The main pipe (201) and the branch pipe (202) are made of corrosion-resistant materials, and the blowdown valve and the safety valve are arranged at the key nodes.

6. The complete test equipment for forced air supplement of a giant hydro-generator unit according to claim 1, characterized in that, The air compressor (1) is a variable frequency air compressor, which can automatically adjust the air supply pressure and flow according to the running state of the unit, and can automatically monitor the running temperature, power, cooling water temperature and lubricating oil level of the unit.

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