Device and method for monitoring oil-water mixing in water guide external circulation system of giant hydro-generator set

Abstract

The present invention discloses a device and method for monitoring oil-water mixing in a water-conducting external circulation system of a giant hydro-turbine generator set. Through the relevant design of the oil discharge pipeline and the use of a cumulative monitoring method, the device can quickly monitor the oil volume change in the water-conducting external circulation system, thereby sensitively discovering whether the system is mixed with oil and water. Through the Venturi effect, the Bernoulli principle is used to control the on and off of the oil discharge pipeline when the dual pumps are running, which can effectively avoid the problem of poor oil discharge when the dual pumps are running; at the same time, it can also avoid false alarms when the dual pumps are running.

Description

Technical Field

[0001] The invention relates to the technical field of giant water turbine generator set operation monitoring, in particular to a device and method for monitoring oil-water mixing in a water guide outer circulation system of a giant water turbine generator set. Background Art

[0002] In order to maintain the stable operation of the hydro-turbine generator set, the radial swing of the turbine needs to be limited within a certain range during its operation. Therefore, multiple water-guide bearings are evenly arranged around the main shaft of the turbine. The water-guide bearings are key components for the safe operation of the turbine set. A special system is used to cool the water-guide bearings to maintain their temperature within a safe range. This system is a water-guide external circulation system.

[0003] The shaftless collar type water-guided bearing and its cooling system is that the guide bush is in direct contact with the main shaft, and the oil tank where the guide bush is located is continuously injected with cooled turbine oil; while the turbine oil takes away the heat, it also lubricates the guide bush and the main shaft.

[0004] Compared with the structure with shaft collar, the shaftless water-guided bearing simplifies the bearing structure, but its lubrication and cooling system is more complicated, the operating conditions are more stringent, and the stable operation requirements of the entire water-guided bearing are more stringent. Typical serious faults of the water-guided external circulation system include: oil mixed with water.

[0005] Under normal circumstances: one water-guided external circulation oil pump is working and the other is standby. Both pumps are running when the system starts, and the standby pump stops after the upper oil tank oil level high node is activated. During operation, when the upper oil tank oil level is low or the oil pump oil flow is low, it starts, and the standby pump stops when the oil level or oil flow reaches the set value.

[0006] In the existing water-guide oil flow direction: the oil pump sucks oil from the external oil tank and enters the water-guide cooler through the oil pipeline. This is the main water source in the oil-water mixing phenomenon. Then it passes through the filter and enters the water-guide upper oil tank to cool the water-guide bearing. When the oil level in the water-guide upper oil tank exceeds the height of the overflow plate, the hot oil after cooling the water-guide bearing is discharged to the external oil tank through the oil drain pipe at the bottom of the upper oil tank; the other part of the oil enters the lower oil tank through the gap between the water-guide bearing and the main shaft, and then is discharged to the external oil tank through the oil drain pipe at the bottom of the lower oil tank.

[0007] Currently, the total amount of oil is calculated and analyzed mainly by observing the oil level in the water guide upper oil tank and combining the oil level changes in the water guide outer oil tank to determine whether the system has water ingress; another method is to monitor whether the water guide outer circulation system has water ingress through an oil-water mixing monitoring device. The current monitoring method has poor sensitivity and often requires very serious water leakage to be discovered, and there are many false alarms.

[0008] Therefore, a system and method for monitoring oil-water mixing is needed for the water-guided external circulation system to monitor and prevent accidents. Summary of the invention

[0009] The present invention provides a device and method for monitoring oil-water mixing in a water-guiding external circulation system of a giant hydro-turbine generator set, aiming to solve the problems of lack of a monitoring device and method for oil-water mixing in the above-mentioned existing water-guiding external circulation system, as well as poor sensitivity and many false alarms.

[0010] In order to solve the above technical problems, the technical solution adopted by the present invention is: a water-conducting external circulation system oil-water mixing monitoring device of a giant hydro-turbine generator set, comprising a water-conducting external circulation system formed by an upper oil tank, a lower oil tank and an outer oil tank, the bottoms of the upper oil tank and the lower oil tank are both provided with oil outlets, and the oil outlets of the upper oil tank and the lower oil tank are respectively connected to a collection tank through a fourth row of oil pipes and a third row of oil pipes, one of the oil outlets of the collection tank is connected to an oil-water mixing monitoring mechanism through a first row of oil pipes, and the oil outlet of the oil-water mixing monitoring mechanism is connected to the outer oil tank;

[0011] The other oil outlet end of the collecting tank is connected to the external oil tank through a second oil discharge pipe, and a control cavity is provided on the second oil discharge pipe. A sealing ball is provided in the control cavity, and the sealing ball and the second oil discharge pipe form a releasable sealing fit;

[0012] The outer oil tank is respectively connected to the first oil pump and the second oil pump to form a lifting fit. The oil outlet ends of the first oil pump and the second oil pump are both connected to the oil inlet end of the same Venturi tube. The oil outlet end of the Venturi tube is connected to the upper oil tank through an oil delivery pipe to form a circulating oil supply fit. The narrowest part of the Venturi tube is connected to the control chamber through a negative pressure pipe, and the sealing ball forms a linkage fit with the Venturi tube.

[0013] Preferably, the oil-water mixing monitoring mechanism includes a fifth oil row pipe, and both ends of the fifth oil row pipe are respectively connected to the first oil row pipe and the external oil tank, a first flow control valve is provided on the side of the fifth oil row pipe close to the external oil tank, the fifth oil row pipe body is horizontally arranged, and a lifting pipe is provided on the fifth oil row pipe body between the first oil row pipe and the first flow control valve, the lifting pipe is arranged vertically upward along the radial direction of the fifth oil row pipe, and the bottom of the lifting pipe is connected with the fifth oil row pipe, an overflow pipe is provided on the top of one side of the lifting pipe, and the lifting pipe and the overflow pipe form an overflow cooperation, a flow switch is provided on the overflow pipe, and the other end of the overflow pipe is connected with the external oil tank through the sixth oil row pipe.

[0014] As a more preferred embodiment, a buffer tube is provided on the lifting pipe between the fifth oil drain pipe and the overflow pipe, the other end of the buffer tube is connected to the external oil tank through the sixth oil drain pipe, and a second flow control valve is provided on the buffer tube.

[0015] Furthermore, the overflow pipe is horizontally arranged along the radial direction of the riser.

[0016] Furthermore, the buffer tube is horizontally arranged along the radial direction of the riser, and the buffer tube is parallel to the overflow tube.

[0017] Preferably, when both the first oil pump and the second oil pump are turned on, the negative pressure formed by the venturi tube in the negative pressure pipe is greater than the gravity of the sealing ball, the sealing ball rises, and the second oil pipe is connected to the external oil tank;

[0018] When at most one of the first oil pump and the second oil pump is turned on, the negative pressure formed by the venturi tube in the negative pressure pipe is less than the gravity of the sealing ball, and the sealing ball blocks the second oil pipe.

[0019] The method for monitoring oil-water mixing in the water guide external circulation system of a giant hydro-turbine generator unit comprises the following steps:

[0020] S1: Install the device to connect the water guide external circulation system and the oil-water mixing monitoring mechanism;

[0021] S2: First-level debugging, keep the fifth oil pipe horizontal, determine the parameters of the first oil pump and the second oil pump, and preliminarily adjust the first flow control valve so that the oil can fill the fifth oil pipe of the oil-water mixing monitoring mechanism in S1 when the single pump is started;

[0022] S3: Secondary debugging, simulating possible error conditions, adjusting and determining the flow value of the first flow control valve, so that the maximum height of the oil in the lifting pipe under the effect of the error is lower than the overflow height of the overflow pipe;

[0023] S4: When monitoring a single pump, return to the parameters determined in S2, maintain the flow value of the first flow control valve in S3, and start the cycle. When water leakage occurs, that is, oil mixed with water, when the parameters in S2 and the flow value in S3 remain unchanged, the oil mixed with water causes the oil volume to increase, and the oil quickly accumulates in the lifting pipe and rises to the overflow height. Through the overflow effect, the oil above the overflow height flows into the overflow pipe, triggering the flow switch to generate a switch signal;

[0024] S5: Emergency response. After receiving the switch signal generated by the flow switch in S4, the staff will respond with emergency processing.

[0025] Preferably, the S2 further includes the following steps:

[0026] S201: Modify the control logic of the oil pump. When the machine is turned on, the first and second oil pumps will run for 60 minutes until the oil temperature stabilizes before stopping the standby pump to maximize the measurement accuracy.

[0027] S202: preliminarily adjusting the flow value of the first flow control valve so that during the operation time of the first oil pump and the second oil pump in S201, the maximum height of the oil lifted in the lifting pipe is lower than the overflow height of the overflow pipe;

[0028] S203: After going through S201 and S202, proceed to the first level debugging in S2.

[0029] More preferably, the steps S201 and S202 further include the following steps:

[0030] When the first oil pump and the second oil pump are running at the same time, the oil flow rate increases when passing through the narrower end of the Venturi tube, and the negative pressure generated in the negative pressure tube exceeds the gravity of the sealing ball, lifting the sealing ball, opening the control chamber, and connecting the second oil pipe to the external oil tank.

[0031] Preferably, S2, S3 and S4 further include the following steps:

[0032] When only a single oil pump is running and the standby oil pump is turned off, the oil flow rate increases when passing through the narrower end of the Venturi tube, and the negative pressure generated in the negative pressure tube is lower than the gravity of the sealing ball. The sealing ball descends and remains at the bottom of the control chamber. The control chamber is blocked, and the second row of oil pipes is disconnected from the external oil tank.

[0033] Beneficial effects of the present invention:

[0034] 1. During the circulation process, overflow is carried out through the lifting pipe of the oil-water mixing monitoring mechanism. The overflowing water enters the overflow pipe to trigger the flow switch, and generates a switch signal for alarm. The sensitivity is high, and because of the size of the giant turbine motor engine unit, the accuracy can be controlled by controlling the size of the lifting pipe and the overflow pipe;

[0035] 2. The flow rate is controlled by the first flow valve to ensure the monitoring accuracy, reduce the impact of the error caused by the system on the monitoring, and prevent misjudgment;

[0036] 3. The buffer tube and the second flow control valve are used to further reduce the error and divert the extra oil when the dual pumps are started to prevent the oil from entering the overflow pipe and causing misjudgment in the monitoring of oil-water mixing;

[0037] 4. The flow of the first oil pipe is assisted by the automatic opening and closing of the second oil pipe. The opening and closing of the second oil pipe are linked to the start-up of the pump. When a single pump is running, the second oil pipe is disconnected, and only the first oil pipe is used to drain oil and monitor oil-water mixing at the same time. When two pumps are running, the second oil pipe is connected. At this time, auxiliary oil discharge ensures the flow in the first oil pipe to prevent a sudden increase in oil from affecting the oil-water mixing monitoring and causing misjudgment. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 It is a schematic diagram of system connection of the present invention;

[0039] Figure 2 A connection diagram of an embodiment of the oil-water mixing monitoring mechanism of the present invention;

[0040] Figure 3 It is a connection diagram of another embodiment of the oil-water mixing monitoring mechanism of the present invention;

[0041] In the figure: 1, upper oil tank; 2, lower oil tank; 3, first row of oil pipes; 4, second row of oil pipes; 5, collecting tank; 6, third row of oil pipes; 7, fourth row of oil pipes;

[0042] 8. Oil-water mixing monitoring mechanism; 801. Fifth oil pipe; 802. First flow control valve; 803. Lifting pipe; 805. Overflow pipe; 806. Flow switch; 807. Sixth oil pipe; 808. Buffer pipe; 809. Second flow control valve;

[0043] 9. External oil tank; 10. First oil pump; 11. Second oil pump; 12. Venturi tube; 13. Control chamber; 14. Sealing ball; 15. Negative pressure pipe; 16. Oil delivery pipe. DETAILED DESCRIPTION

[0044] As follows, embodiments are further described with reference to the accompanying drawings.

[0045] like Figure 1 As shown, as a preferred embodiment 1, a water-conducting external circulation system oil-water mixing monitoring device for a giant hydro-turbine generator set comprises a water-conducting external circulation system formed by an upper oil tank 1, a lower oil tank 2 and an outer oil tank 9, the upper oil tank 1 and the lower oil tank 2 are both provided with oil outlets at the bottom, and the oil outlets of the upper oil tank 1 and the lower oil tank 2 are respectively connected to a collecting tank 5 through a fourth oil row pipe 7 and a third oil row pipe 6, one of the oil outlets of the collecting tank 5 is connected to an oil-water mixing monitoring mechanism 8 through a first oil row pipe 3, and the oil outlet of the oil-water mixing monitoring mechanism 8 is connected to the outer oil tank 9;

[0046] The other oil outlet end of the collecting tank 5 is connected to the outer oil tank 9 through the second oil discharge pipe 4. The second oil discharge pipe 4 is provided with a control chamber 13. A sealing ball 14 is provided in the control chamber 13. The sealing ball 14 and the second oil discharge pipe 4 form a releasable sealing fit.

[0047] The outer oil tank 9 is respectively connected to the first oil pump 10 and the second oil pump 11 to form a lifting fit. The oil outlet ends of the first oil pump 10 and the second oil pump 11 are both connected to the oil inlet end of the same venturi tube 12. The oil outlet end of the venturi tube 12 is connected to the upper oil tank 1 through an oil delivery pipe 16 to form a circulating oil supply fit. The narrowest part of the venturi tube 12 is connected to the control chamber 13 through a negative pressure pipe 15, and the sealing ball 14 forms a linkage fit with the venturi tube 12.

[0048] Embodiment 1 provides an oil-water mixing monitoring device for a water-guiding external circulation system of a giant hydro-turbine generator set. An oil-water mixing monitoring mechanism 8 is added to the existing water-guiding external circulation system formed by an upper oil tank 1, a lower oil tank 2 and an outer oil tank 9, so as to realize the monitoring of oil-water mixing. The oil in the upper oil tank 1 and the lower oil tank 2 is respectively collected into a collection tank 5 through a fourth oil pipe 7 and a third oil pipe 6. One of the oil outlet ends of the collection tank 5 is used as a conventional oil outlet end, which is always kept connected and enters the oil-water mixing monitoring mechanism 8 through the first oil pipe 3. The oil is monitored for water-oil mixing, and after the monitoring, the oil enters the outer oil tank 9 and waits to be lifted up to the upper oil tank 1 by the oil pump for circulation. Conventional use and oil-water mixing monitoring are usually completed under the action of a single pump. One of the first oil pump 10 and the second oil pump 11 is used as a main pump and the other is used as a standby pump. The main pump pumps the oil in the outer oil tank 9 into the venturi tube 12 and re-enters the upper oil tank 1 through the oil delivery pipe 16 to form a circulation, circulate cooling and lubricate the water guide shoe, and monitor whether there is oil-water mixing in the process;

[0049] Under certain circumstances, dual pump operation may be required, that is, one of the first oil pump 10 and the second oil pump 11 is used as the main pump and the other is used as the backup pump, and both pumps are activated. At this time, the first oil pump 10 and the second oil pump 11 both pump the oil in the outer oil tank 9 into the venturi tube 12, and the inlet speed and flow rate are increased. When passing through the narrowest section of the venturi tube 12, a larger negative pressure will be generated in the negative pressure tube 15 than when a single pump is in operation. The negative pressure at this time exceeds the gravity of the sealing ball 14, and the sealing ball 14 is lifted to the top of the control chamber 13. At this time, the control chamber 13 is opened, so that the second oil discharge pipe 4 is connected to the outer oil tank 9, and oil is discharged simultaneously through the first oil discharge pipe 3 and the second oil discharge pipe 4. On the one hand, it prevents the total pump stroke from increasing and not being able to discharge the oil in time, thereby increasing the oil discharge pressure of the upper oil tank 1, the lower oil tank 2 and the collecting tank 5. On the other hand, it prevents excessive oil from entering the first oil discharge pipe 3, affecting the monitoring result of the oil-water mixing monitoring mechanism 8, and causing misjudgment.

[0050] Preferably, the fourth oil pipe 7 and the third oil pipe 6 should have a certain diameter to ensure that no oil is accumulated in the upper oil tank 1 and the lower oil tank 2 to avoid affecting the measurement accuracy.

[0051] like Figure 2As shown, as a preferred embodiment 2, the oil-water mixing monitoring mechanism 8 includes a fifth oil discharge pipe 801, and the two ends of the fifth oil discharge pipe 801 are respectively connected to the first oil discharge pipe 3 and the external oil tank 9, a first flow control valve 802 is provided on the side of the fifth oil discharge pipe 801 close to the external oil tank 9, the fifth oil discharge pipe 801 is arranged horizontally, and a lifting pipe 803 is provided on the fifth oil discharge pipe 801 between the first oil discharge pipe 3 and the first flow control valve 802, the lifting pipe 803 is arranged vertically upward along the radial direction of the fifth oil discharge pipe 801, and the bottom of the lifting pipe 803 is connected with the fifth oil discharge pipe 801, an overflow pipe 805 is provided on the top of one side of the lifting pipe 803, and the lifting pipe 803 and the overflow pipe 805 form an overflow match, a flow switch 806 is provided on the overflow pipe 805, and the other end of the overflow pipe 805 is connected with the external oil tank 9 through the sixth oil discharge pipe 807.

[0052] Embodiment 2 provides a specific structure of the oil-water mixing monitoring mechanism 8. The device determines whether there is oil-water mixing by raising the liquid level. In the case of the main shaft of the turbine, the leakage of the water guide outer circulation is fast and large, so it will cause the amount of oil in the circulation to increase rapidly. This point is used to design the structure of embodiment 2. Under normal circumstances, the cooled oil is discharged along the first row of oil pipes 3 and enters the fifth row of oil pipes 801. The oil smoothly enters the external oil tank 9 through the fifth row of oil pipes 801.

[0053] When there is a water leak, that is, oil mixed with water, water will enter quickly and in large quantities, causing an increase in oil, while the pump stroke in the cycle has not changed, and the first flow control valve 802 has not changed, resulting in a large amount of oil entering the fifth oil discharge pipe 801 and quickly accumulating in the lifting pipe 803. When the accumulated amount exceeds the overflow height of the overflow pipe 805, the oil enters the overflow pipe 805 and triggers the flow switch 806 to generate a switching signal, and enters the external oil tank 9 through the sixth oil discharge pipe 807. After receiving the switching signal, the staff or the background can know that oil is mixed with water and take emergency and maintenance measures.

[0054] Preferably, the total oil discharge volume of the first oil discharge pipe 3 and the second oil discharge pipe 4 is greater than the oil pump flow rate when the dual pumps are in operation. Therefore, when the dual pumps are in operation, the liquid level in the lifting pipe 803 will not rise to the overflow pipe 805, causing a false alarm of the oil-water mixing device.

[0055] As a preferred embodiment 3, if the structure of embodiment 2 is adopted, buffering is set by controlling the flow of the first flow control valve 802, the height and diameter of the lifting pipe 803, and the overflow height of the overflow pipe 805. During the operation of the system, the oil discharge volume increases to a certain extent due to reasons such as increased oil pump efficiency or changes in oil temperature. At this time, certain buffering measures are required to ensure that the height of the oil lifted in the lifting pipe 803 is lower than the overflow height while meeting the maximum tolerable error, so as to ensure the accuracy of monitoring and prevent misjudgment.

[0056] like Figure 3 As shown, as a preferred embodiment 4, a buffer pipe 808 is provided on the lifting pipe 803 located between the fifth oil discharge pipe 801 and the overflow pipe 805, and the other end of the buffer pipe 808 is connected to the external oil tank 9 through the sixth oil discharge pipe 807, and a second flow control valve 809 is provided on the buffer pipe 808.

[0057] Embodiment 4 provides another structure of the oil-water mixing monitoring mechanism 8 on the basis of Embodiment 2. On the basis of Embodiment 2, a buffer tube 808 and a second flow control valve 809 are added. Compared with the buffer method proposed in Embodiment 3 for Embodiment 2, Embodiment 4 can be more simplified. The buffer arrangement can be completed by controlling the diameter of the buffer tube 808 and the flow of the second flow control valve 809. During the operation of the system, the oil discharge volume increases to a certain extent due to reasons such as increased oil pump efficiency or changes in oil temperature. After the erroneously increased oil enters the lifting pipe 803, it will be directly discharged into the sixth oil discharge pipe 807 through the buffer tube 808 and the second flow control valve 809, and finally enter the external oil tank 9. Even in the case of the largest acceptable error, it is sufficient to ensure that the height of the remaining oil after the buffer tube 808 is diverted is lower than the overflow height to ensure the accuracy of monitoring and prevent misjudgment.

[0058] As a preferred embodiment 5, the overflow pipe 805 is arranged horizontally along the radial direction of the lifting pipe 803 to ensure the smooth passage of the oil and facilitate the overflow to flow into the pipe to trigger the flow switch 806.

[0059] As a preferred embodiment 6, the buffer pipe 808 is horizontally arranged along the radial direction of the riser 803, and the buffer pipe 808 is parallel to the overflow pipe 805. This is convenient for smooth flow guidance and easy arrangement.

[0060] As a preferred embodiment 7, when the first oil pump 10 and the second oil pump 11 are both turned on, the negative pressure formed by the venturi tube 12 in the negative pressure pipe 15 is greater than the gravity of the sealing ball 14, the sealing ball 14 rises, and the second oil drain pipe 4 is connected to the external oil tank 9;

[0061] When at most one of the first oil pump 10 and the second oil pump 11 is turned on, the negative pressure formed by the venturi tube 12 in the negative pressure pipe 15 is smaller than the gravity of the sealing ball 14 , and the sealing ball 14 blocks the second oil drain pipe 4 .

[0062] Example 7 provides the specific conditions of the opening and closing of the second oil discharge pipe 4 in the case of dual pumps and single pumps. According to the Venturi effect: when the restricted flow passes through the reduced flow cross section, the fluid velocity increases, and the flow velocity is inversely proportional to the flow cross section. According to Bernoulli's law, the increase in flow velocity is accompanied by a decrease in fluid pressure, which is the common Venturi phenomenon. In layman's terms, this effect refers to the low pressure generated near the high-speed flowing fluid, thereby generating an adsorption effect.

[0063] Therefore, when the first oil pump 10 and the second oil pump 11 are both turned on, the negative pressure formed by the venturi tube 12 in the negative pressure pipe 15 is greater than the gravity of the sealing ball 14, the sealing ball 14 rises, and the second oil drain pipe 4 is connected to the external oil tank 9;

[0064] When at most one of the first oil pump 10 and the second oil pump 11 is turned on, the negative pressure formed by the venturi tube 12 in the negative pressure pipe 15 is less than the gravity of the sealing ball 14, and the sealing ball 14 blocks the second oil discharge pipe 4. This facilitates linkage with the pump, automatically opens and closes according to the pump opening situation, improves the stability of the system, and prevents the monitoring mechanism from making misjudgments.

[0065] As a preferred embodiment 8, the Venturi tube 12 is not necessarily a standard Venturi tube 12. The scheme uses a Venturi-like tube that is thick at both ends and thin in the middle. As long as it can be achieved that when the restricted flow passes through a reduced flow section, the flow velocity of the fluid increases, thereby generating negative pressure in the negative pressure tube 15 for moving the sealing ball 14.

[0066] As a preferred embodiment 9, the calibers of the overflow pipe 805 and the buffer pipe 808 are both smaller than the caliber of the lifting pipe 803, so as to ensure the response speed and quickly start the flow switch 806 after overflow, while ensuring that the buffering amount of the buffer pipe 808 is not too large, which affects the monitoring accuracy and causes monitoring lag. The caliber of the lifting pipe 803 is close to that of the fifth oil discharge pipe 801.

[0067] As a preferred embodiment 10, the fifth oil pipe 801 is located at the front side of the lifting pipe 803 and a third oil pump and a flow meter can be set to control the flow rate and flow velocity in the monitoring mechanism to further improve the monitoring accuracy.

[0068] As a preferred embodiment 11, a method for monitoring oil-water mixing using the oil-water mixing monitoring device of the water conduction external circulation system of a giant hydro-turbine generator set as described above comprises the following steps:

[0069] S1: Install the device, connect the water-guiding external circulation system and the oil-water mixing monitoring mechanism 8, ensure the circulation of the system, and monitor during the circulation process;

[0070] S2: First-level debugging, keep the fifth oil pipe 801 horizontal, determine the parameters of the first oil pump 10 and the second oil pump 11, and preliminarily adjust the first flow control valve 802, so that the oil fills the fifth oil pipe 801 of the oil-water mixed monitoring mechanism 8 in S1 when a single pump is started. The first-level debugging is used to determine the output of each pump and the flow of the first flow control valve 802 when the main pump is turned on, to ensure that when the main pump is turned on, the oil fills the fifth oil pipe 801 of the oil-water mixed monitoring mechanism 8 in S1, and basically does not overflow into the lifting pipe 803, so as to ensure that when water leaks, the oil-water mixed oil can be quickly lifted in the lifting pipe 803, and when there is no leakage, the oil circulates smoothly for cooling and lubrication;

[0071] S3: Secondary debugging, simulating possible error conditions, adjusting and determining the flow value of the first flow control valve 802, so that the maximum height of the oil in the lifting pipe 803 under the effect of the error is lower than the overflow height of the overflow pipe 805. Secondary debugging is used for fine-tuning, so that the system error condition without water leakage occurs in time when the system is running with a single pump, and the oil height in the lifting pipe 803 is always lower than the overflow height, so as to prevent the error in the system circulation from causing the oil to rise and affecting the monitoring of oil-water mixing and causing misjudgment;

[0072] S4: When monitoring a single pump, return to S2 to determine the parameters to be used, maintain the flow value of the first flow control valve 802 in S3, and start the cycle. When water leakage occurs, that is, oil mixed with water, when the parameters in S2 and the flow value in S3 remain unchanged, the oil mixed with water causes the oil volume to increase, and the oil quickly accumulates in the lifting pipe 803 and rises to the overflow height. Through the overflow effect, the oil above the overflow height flows into the overflow pipe 805, triggering the flow switch 806 to generate a switch signal. S4 is already working normally. Generally speaking, under normal circumstances, only the main pump will be turned on, and the monitoring process is mainly carried out when the main pump is running. In order to prevent the dual pumps from affecting the monitoring accuracy, the monitoring under the dual pump condition should also be removed in S2. When only the main pump is running, the oil is circulated in the system while the oil-water mixing monitoring is also carried out. Under normal circumstances, the oil directly enters the outer oil tank 9 through the fifth row of oil pipes 801 and the first flow control valve 802, and re-enters the upper oil tank 1 under the lifting of the main pump, and the cycle repeats. During the process, due to factors such as the efficiency of the main pump and the oil temperature, the oil may be lifted in the lifting pipe 803, but after the debugging of S2 and S3, it will not enter the overflow pipe 805. When there is water leakage, the oil will rise rapidly, quickly rise to the overflow height in the lifting pipe 803 and enter the overflow pipe 805. When the oil flows through the overflow pipe 805, the flow switch 806 is triggered to change its state, and a switch signal is generated and transmitted to the staff or the background;

[0073] S5: Emergency response. After receiving the switch signal generated by the flow switch 806 in S4, the staff will make a response emergency treatment. The received switch signal is used to determine whether there is a water leakage.

[0074] As a preferred embodiment 12, the S2 further includes the following steps:

[0075] S201: modify the control logic of the oil pump. When the machine is turned on, the first oil pump 10 and the second oil pump 11 are operated for 60 minutes until the oil temperature is stable before stopping the standby pump, so as to maximize the measurement accuracy.

[0076] S202: preliminarily adjusting the flow value of the first flow control valve 802 so that during the operation time of the first oil pump 10 and the second oil pump 11 in S201, the maximum height of the oil lifted in the lifting pipe 803 is lower than the overflow height of the overflow pipe 805;

[0077] S203: After S201 and S202, perform the first-level debugging in S2 to ensure the debugging accuracy as much as possible and reduce the interference of system errors on monitoring.

[0078] As a preferred embodiment 13, if the structure in embodiment 2 is adopted, S202 is directly adopted to perform adjustment;

[0079] If the mechanism in Example 4 is adopted, then in S202, not only the first flow control valve 802 but also the second flow control valve 809 needs to be adjusted.

[0080] As a preferred embodiment 14, the S201 and S202 further include the following steps:

[0081] When the first oil pump 10 and the second oil pump 11 are running simultaneously, the flow velocity of the oil increases when passing through the narrower end of the venturi tube 12, and the negative pressure generated in the negative pressure tube 15 exceeds the gravity of the sealing ball 14, lifting the sealing ball 14, opening the control chamber 13, and connecting the second oil discharge pipe 4 to the external oil tank 9.

[0082] As a preferred embodiment 15, the S2, S3 and S4 further include the following steps:

[0083] When only a single oil pump is running and the standby oil pump is turned off, the oil flow rate increases when passing through the narrower end of the venturi tube 12, and the negative pressure generated in the negative pressure tube 15 is lower than the gravity of the sealing ball 14. The sealing ball 14 drops and remains at the bottom of the control chamber 13, the control chamber 13 is blocked, and the second oil pipe 4 is disconnected from the external oil tank 9. When controlling the flow of the two pumps, it is also necessary to refer to the state of the sealing ball 14, strictly ensure that when the main pump is started, the sealing ball 14 does not move, so that the second oil pipe 4 is blocked, and when the dual pumps are started, the negative pressure generated exceeds the gravity of the sealing ball 14, thereby lifting the sealing ball 14 to open the control chamber 13, so that the second oil pipe 4 is connected to the auxiliary oil discharge.

Claims

1. The oil-water mixing monitoring device for the water conduction external circulation system of a giant hydro-turbine generator set is characterized by: The invention comprises a water-conducting external circulation system formed by an upper oil tank (1), a lower oil tank (2) and an outer oil tank (9), characterized in that the bottoms of the upper oil tank (1) and the lower oil tank (2) are both provided with oil outlets, and the oil outlets of the upper oil tank (1) and the lower oil tank (2) are respectively connected to a collecting tank (5) through a fourth oil row pipe (7) and a third oil row pipe (6), one of the oil outlets of the collecting tank (5) is connected to an oil-water mixing monitoring mechanism (8) through a first oil row pipe (3), and the oil outlet of the oil-water mixing monitoring mechanism (8) is connected to the outer oil tank (9); The other oil outlet end of the collecting tank (5) is connected to the outer oil tank (9) via a second oil discharge pipe (4); a control chamber (13) is provided on the second oil discharge pipe (4); a sealing ball (14) is provided in the control chamber (13); and the sealing ball (14) and the second oil discharge pipe (4) form a releasable sealing fit; The oil-water mixing monitoring mechanism (8) comprises a fifth oil row pipe (801), and the two ends of the fifth oil row pipe (801) are respectively connected to the first oil row pipe (3) and the external oil tank (9), a first flow control valve (802) is provided on the side of the fifth oil row pipe (801) close to the external oil tank (9), the fifth oil row pipe (801) is arranged horizontally, and a lifting pipe (802) is provided on the fifth oil row pipe (801) between the first oil row pipe (3) and the first flow control valve (802). 3) The lifting pipe (803) is arranged vertically upward along the radial direction of the fifth oil discharge pipe (801), and the bottom of the lifting pipe (803) is connected to the fifth oil discharge pipe (801). An overflow pipe (805) is provided at the top of one side of the lifting pipe (803), and the lifting pipe (803) and the overflow pipe (805) form an overflow match. A flow switch (806) is provided on the overflow pipe (805), and the other end of the overflow pipe (805) is connected to the external oil tank (9) through the sixth oil discharge pipe (807); The outer oil tank (9) is respectively connected to the first oil pump (10) and the second oil pump (11) to form a lifting fit; the oil outlet ends of the first oil pump (10) and the second oil pump (11) are both connected to the oil inlet end of the same venturi tube (12); the oil outlet end of the venturi tube (12) is connected to the upper oil tank (1) via an oil delivery pipe (16) to form a circulating oil supply fit; the narrowest part of the venturi tube (12) is connected to the control chamber (13) via a negative pressure pipe (15), and the sealing ball (14) forms a linkage fit with the venturi tube (12).

2. The oil-water mixing monitoring device for the water conduction external circulation system of a giant hydro-turbine generator set according to claim 1 is characterized in that: A buffer pipe (808) is provided on the lifting pipe (803) between the fifth oil discharge pipe (801) and the overflow pipe (805); the other end of the buffer pipe (808) is connected to the external oil tank (9) via the sixth oil discharge pipe (807); and a second flow control valve (809) is provided on the buffer pipe (808).

3. The oil-water mixing monitoring device for the water conduction external circulation system of a giant hydro-turbine generator set according to claim 2 is characterized in that: The overflow pipe (805) is arranged horizontally along the radial direction of the lifting pipe (803).

4. The oil-water mixing monitoring device for the water conduction external circulation system of a giant hydro-turbine generator set according to claim 3 is characterized in that: The buffer pipe (808) is arranged horizontally along the radial direction of the riser (803), and the buffer pipe (808) is parallel to the overflow pipe (805).

5. The oil-water mixing monitoring device for the water conduction external circulation system of a giant hydro-turbine generator set according to claim 4 is characterized in that: When the first oil pump (10) and the second oil pump (11) are both turned on, the negative pressure formed by the venturi tube (12) in the negative pressure tube (15) is greater than the gravity of the sealing ball (14), the sealing ball (14) rises, and the second oil discharge pipe (4) is connected to the external oil tank (9); When at most one of the first oil pump (10) and the second oil pump (11) is turned on, the negative pressure formed by the venturi tube (12) in the negative pressure pipe (15) is smaller than the gravity of the sealing ball (14), and the sealing ball (14) blocks the second oil drain pipe (4).

6. A method for monitoring oil-water mixing using the oil-water mixing monitoring device for the water conduction external circulation system of a giant hydro-turbine generator set according to any one of claims 1 to 5, characterized in that: The following steps are involved: S1: Installing a device to connect the water-guiding external circulation system and the oil-water mixing monitoring mechanism (8); S2: First-level debugging, keeping the fifth oil pipe (801) level, determining the parameters of the first oil pump (10) and the second oil pump (11), and preliminarily adjusting the first flow control valve (802) so that the oil fills the fifth oil pipe (801) of the oil-water mixing monitoring mechanism (8) in S1 when the single pump is started; S3: Secondary debugging, simulating the error situation, adjusting and determining the flow value of the first flow control valve (802), so that the maximum height of the oil lifted in the lifting pipe (803) under the effect of the error is lower than the overflow height of the overflow pipe (805); S4: When monitoring a single pump, return to the parameters determined in S2, maintain the flow value of the first flow control valve (802) in S3, and start the circulation. When water leakage occurs, that is, oil-water mixing occurs, while the parameters in S2 and the flow value in S3 remain unchanged, the oil-water mixing causes the oil volume to increase, and the oil quickly accumulates in the lifting pipe (803) and rises to the overflow height. Through the overflow effect, the oil above the overflow height flows into the overflow pipe (805), triggering the flow switch (806) to generate a switch signal; S5: Emergency response. After receiving the switch signal generated by the flow switch (806) in S4, the staff will respond with emergency processing.

7. The method for monitoring oil-water mixing in the water conduction external circulation system of a giant hydro-turbine generator set according to claim 6 is characterized in that: The S2 also includes the following steps: S201: modify the control logic of the oil pump. When the machine is turned on, the first oil pump (10) and the second oil pump (11) are operated for 60 minutes until the oil temperature is stable before stopping the standby pump, thereby maximizing the measurement accuracy. S202: preliminarily adjusting the flow value of the first flow control valve (802) so that during the operation time of the first oil pump (10) and the second oil pump (11) in S201, the maximum height of the oil lifted in the lifting pipe (803) is lower than the overflow height of the overflow pipe (805); S203: After going through S201 and S202, proceed to the first level debugging in S2.

8. The method for monitoring oil-water mixing in the water conduction external circulation system of a giant hydro-turbine generator set according to claim 7 is characterized in that: The S201 and S202 further include the following steps: When the first oil pump (10) and the second oil pump (11) are operated simultaneously, the oil flow rate increases when passing through the narrower end of the venturi tube (12), and the negative pressure generated in the negative pressure tube (15) exceeds the gravity of the sealing ball (14), thereby lifting the sealing ball (14), opening the control chamber (13), and connecting the second oil discharge pipe (4) to the external oil tank (9).

9. The method for monitoring oil-water mixing in the water conduction external circulation system of a giant hydro-turbine generator set according to claim 8, characterized in that: The S2, S3 and S4 all further include the following steps: When only a single oil pump is running and the standby oil pump is shut down, the oil flow rate increases when passing through the narrower end of the venturi tube (12), and a negative pressure is generated in the negative pressure tube (15) that is lower than the gravity of the sealing ball (14). The sealing ball (14) descends and remains at the bottom of the control chamber (13), the control chamber (13) is blocked, and the second row oil pipe (4) is disconnected from the external oil tank (9).

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