Self-stabilizing roof drainage system and control method thereof

Abstract

The present application provides a self-stabilizing roof drainage system, including a drainage pipeline, a main drainage outlet is provided at one end of the drainage pipeline, a first branch and a second branch are provided in parallel at the other end of the drainage pipeline, the first branch and the second branch are respectively provided with a first branch water inlet and a second branch water inlet, the height of the main drainage outlet is lower than the heights of the first branch water inlet and the second branch water inlet, the first branch is provided with a drainage pump, the second branch is provided with a flow regulating device, the drainage pipeline is also provided with a ventilation branch connected in parallel with the first branch and the second branch, and the ventilation branch is provided with a vacuum solenoid valve, thereby solving the problem of frequent starting of the existing roof drainage pump.

Description

Technical Field

[0001] The present invention relates to the field of water turbine generator set top cover drainage, in particular to a self-stabilizing top cover drainage system and a control method thereof. Background Art

[0002] In mixed-flow or axial-flow units equipped with cylindrical valves, water leakage from the main shaft seal inside the top cover cannot be drained by gravity due to obstruction from the outside of the top cover. Existing units use multiple top cover drainage pumps for drainage. Since the top cover of a vertical hydro-turbine generator set houses a water-guided bearing, if the bearing is submerged by accumulated water within the top cover, it will submerge the bearing, causing the unit to malfunction and resulting in significant economic losses. Therefore, the top cover drainage pump must meet the goal of high reliability. Furthermore, to provide emergency drainage, multiple drainage pumps are required for emergency drainage. Furthermore, while meeting the requirements for high reliability and emergency drainage, energy conservation and environmental protection, as well as minimal energy consumption, should be maximized.

[0003] The limited space inside the top cover results in a small water reservoir capacity. At the same time, to ensure emergency drainage in an emergency, a high-power top cover drainage pump is required. This causes the top cover pump to start intermittently, with each run time being short. The motor heats up after operation, which causes thermal expansion, but the expansion rate varies between different parts. Similarly, there is a contraction process during cooling. Because the top cover pump runs for a short time each time, it frequently enters transient processes such as heating up, cooling down, starting the pump, and stopping the pump. During these transient processes, the top cover pump operates in a non-optimal operating area and is extremely susceptible to damage due to thermal expansion and contraction.

[0004] The existing roof drainage system has paid a huge price to meet the requirements of high reliability and emergency drainage functions, which makes the cost of the entire system high. The intermittent operation of the roof pump has caused many defects and high maintenance costs. The entire system is mainly driven by electricity, which makes the equipment energy consumption high. Therefore, the development of a high-reliability, high-efficiency, energy-saving and environmentally friendly roof drainage system is a problem that the industry urgently needs to solve. Summary of the Invention

[0005] The present invention provides a self-stabilizing top cover drainage system and a control method thereof, which solves the problem of frequent startup of the existing top cover drainage pump.

[0006] In order to solve the above technical problems, the technical solution adopted by the present invention is: a self-stabilizing top cover drainage system, including a drainage pipeline, a main drainage outlet is provided at one end of the drainage pipeline, and a first branch and a second branch are provided in parallel at the other end of the drainage pipeline, the first branch and the second branch are respectively provided with a first branch water inlet and a second branch water inlet, the height of the main drainage outlet is lower than the height of the first branch water inlet and the second branch water inlet, the first branch is provided with a drainage pump, the second branch is provided with a flow regulating device, the drainage pipeline is also provided with a ventilation branch connected in parallel with the first branch and the second branch, and the ventilation branch is provided with a vacuum solenoid valve.

[0007] The first branch and the second branch are connected in parallel. The drain pump works first to exhaust the air in the first branch and start draining. As the flow rate increases and the pressure decreases, the air in the second branch is also pumped out, and water begins to enter from the second branch and flow to the main drain outlet. At this time, the drain pump is turned off and drainage is only done by siphon.

[0008] Since the flow regulating device has a flow regulating function, siphon drainage can be maintained for a long time. Since the drainage pump has not been used for a long time, in order to check whether the drainage pump is functioning normally, the drainage pump needs to be started regularly. However, during siphon drainage, the water level in the top cover may not meet the starting water level of the pump. At this time, it is necessary to open the vacuum solenoid valve first and let air into the drainage pipe to destroy the siphon effect. After a period of leakage, the water level rises to a safe water level and then start the drainage pump.

[0009] In the preferred solution, the flow regulating device includes a cylinder, the side wall of the cylinder is provided with a drain outlet and a water inlet arranged oppositely, a slidable floating valve core is provided in the cylinder, a first gear and a second gear that are meshed with each other are also provided on the cylinder, a rotating rod and a shift lever are also provided, the two ends of the rotating rod are respectively connected to the float and the first gear, one end of the shift lever shifts the floating valve core, and the other end of the shift lever is connected to the second gear, and the height of the float changes to change the area of ​​the drain outlet blocked by the floating valve core.

[0010] The second gear and the lever are connected as one. The rotation center of the lever is the center of the second gear, and the rotation center of the rotating rod is the center of the first gear. When the float sinks, the lever pushes the floating valve core downward to move it downward. The drain outlet is located near the bottom of the cylinder. The floating valve core moves downward and gradually blocks the drain outlet, reducing the cross-sectional area of ​​the channel between the water inlet and the drain outlet, gradually reducing the flow rate, and delaying drainage.

[0011] When the float drops to the lowest point, there is still a certain height of water in the top cover. There are two options for traditional float valves. The more common one is that the valve core completely blocks the drainage channel and no longer drains water. The other is to maintain a certain drainage channel, but because the float has reached its position limit and no longer plays a role in regulating the opening, the remaining water will be quickly drained. The above two situations will interrupt the siphon effect.

[0012] In this case, the buoyancy of the floating valve core is insufficient, causing it to descend, further reducing the cross-sectional area of ​​the passage between the water inlet and the drain outlet, thus reducing the flow rate and preventing excessive flow from rapidly draining the remaining water and interrupting the siphon. When the siphon drainage volume is less than the leakage volume, the top cover is gradually replenished, causing the floating valve core to rise, increasing the cross-sectional area of ​​the passage between the water inlet and the drain outlet and the flow rate. As a result, the siphon drainage is maintained dynamically for a long time, and the drain pump does not need to be started frequently.

[0013] In a preferred solution, a threaded sleeve is provided on the floating valve core, and the rotating rod is threadably connected to the floating ball.

[0014] The initial height of the floating valve core and the height of the lowest end of the float ball can be easily adjusted.

[0015] In a preferred solution, the drainage pipeline also includes one or more backup pumps.

[0016] When a fault occurs and leakage increases suddenly, after the siphon is destroyed, the drainage pump and the backup pump work at the same time to quickly pump out the accumulated water.

[0017] In a preferred solution, a second check valve is further provided on the first branch, a first check valve is further provided on the second branch, and a third check valve is further provided on the ventilation branch.

[0018] Each check valve allows each branch to be connected to the main line in one direction, avoiding mutual influence between branches.

[0019] The second check valve has a spring and requires a certain starting force. Since the siphon negative pressure is small, the second check valve cannot be pushed open and the first branch does not pump water.

[0020] Including control methods,

[0021] The drainage pump starts and the first branch is drained;

[0022] After the air in the second branch is exhausted, the drainage pump stops and the second branch siphons the water out;

[0023] The flow regulating device adaptively adjusts the opening size of the water inlet according to the water level in the top cover;

[0024] When the siphon drainage time reaches the specified value, the vacuum solenoid valve opens, air enters the drainage pipe, and the siphon drainage is destroyed;

[0025] Wait for a certain period of time until the water level reaches a safe level, and then repeat steps S1-S4.

[0026] The beneficial effects of the present invention are as follows: without reducing the reliability of the system, the problem of excessive energy consumption of the existing top cover drainage pump can be solved; the first startup only requires a short startup time and then the pump is stopped to automatically form stable gravity drainage, so continuous and stable drainage can be achieved in the event of a power outage by setting a UPS power supply, thereby greatly improving the reliability of the equipment; three submersible pumps are controlled only by two data, water level and time, with simple control logic, few adjustment parameters and high reliability; the floating valve core can gradually close the drain outlet in two stages under the influence of the float and its own buoyancy, so that the linear correlation between the water level height and the flow rate is higher. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The present invention will be further described below with reference to the accompanying drawings and examples.

[0028] Figure 1 It is a system diagram of the present invention.

[0029] Figure 2 It is a schematic diagram of the connection of the main devices of the present invention.

[0030] Figure 3 It is an external schematic diagram of the flow regulating device of the present invention.

[0031] Figure 4 The flow regulating device of the present invention is in the state Figure 1 .

[0032] Figure 5 The flow regulating device of the present invention is in the state Figure 2 .

[0033] Figure 6 The flow regulating device of the present invention is in the state Figure 3 .

[0034] Figure 7 This is a diagram of the operating conditions of the vacuum solenoid valve of the present invention.

[0035] In the figure: flow regulating device 1; floating valve core 101; screw sleeve 102; float 103; rotating rod 104; first gear 105; second gear 106; shift lever 107; drain outlet 108; water inlet 109; drain pump 2; vacuum solenoid valve 3; first check valve 4; second check valve 5; third check valve 6; standby pump 7. DETAILED DESCRIPTION

[0036] Example 1:

[0037] like Figure 1-7A self-stabilizing roof drainage system includes a drainage pipeline, a main drainage outlet is provided at one end of the drainage pipeline, a first branch and a second branch are provided in parallel at the other end of the drainage pipeline, the first branch and the second branch are respectively provided with a first branch water inlet and a second branch water inlet, the height of the main drainage outlet is lower than the heights of the first branch water inlet and the second branch water inlet, the first branch is provided with a drainage pump 2, the second branch is provided with a flow regulating device 1, the drainage pipeline is also provided with a ventilation branch connected in parallel with the first branch and the second branch, and the ventilation branch is provided with a vacuum solenoid valve 3.

[0038] The first branch and the second branch are connected in parallel. Drain pump 2 works first to exhaust the air in the first branch and start draining. As the flow rate increases and the pressure decreases, the air in the second branch is also pumped out, and water begins to enter from the second branch and flow to the main drain outlet. At this time, drain pump 2 is turned off and drainage is only done by siphon.

[0039] Since the flow regulating device 1 has a flow regulating function, siphon drainage can be maintained for a long time. Since the drainage pump 2 has not been used for a long time, in order to check whether the drainage pump 2 is functioning normally, the drainage pump 2 needs to be started regularly. However, during siphon drainage, the water level in the top cover may not meet the starting water level of the pump. At this time, it is necessary to open the vacuum solenoid valve 3 first, and let air into the drainage pipe to destroy the siphon effect. When the water level rises to a safe water level after leakage for a period of time, the drainage pump 2 can be started again.

[0040] In the preferred embodiment, the flow regulating device 1 includes a cylinder, the side wall of which is provided with a drain outlet 108 and a water inlet 109 arranged opposite to each other, a slidable floating valve core 101 is provided in the cylinder, and a first gear 105 and a second gear 106 that are meshed with each other are also provided on the cylinder, as well as a rotating rod 104 and a shift rod 107. The two ends of the rotating rod 104 are respectively connected to the float 103 and the first gear 105. One end of the shift rod 107 shifts the floating valve core 101, and the other end of the shift rod 107 is connected to the second gear 106. The height of the float 103 changes so that the area of ​​the drain outlet 108 blocked by the floating valve core 101 changes.

[0041] The second gear 106 and the shift rod 107 are connected as one. The rotation center of the shift rod 107 is the center of the second gear 106, and the rotation center of the rotating rod 104 is the center of the first gear 105. When the float 103 sinks, the shift rod 107 pushes the floating valve core 101 downward to move it downward. The drain outlet 108 is provided near the bottom end of the cylinder. The floating valve core 101 moves downward and gradually blocks the drain outlet 108, reducing the cross-sectional area of ​​the channel between the water inlet 109 and the drain outlet 108, gradually reducing the flow rate, and delaying drainage.

[0042] When the float 103 drops to the lowest point, there is still a certain height of water in the top cover. There are two options for traditional float valves. The more common one is that the valve core completely blocks the drainage channel and no longer drains water. The other is to maintain a certain drainage channel, but because the float 103 has reached its position limit and no longer plays a role in regulating the opening, the remaining water will be quickly drained. The above two situations will interrupt the siphon effect.

[0043] In this case, the buoyancy applied to float valve core 101 is insufficient, causing it to descend, further reducing the cross-sectional area of ​​the passageway between water inlet 109 and drain outlet 108. This reduces the flow rate and prevents excessive flow, which would quickly drain the remaining water and interrupt the siphoning process. When the siphoning volume is less than the leakage volume, the top cover is gradually replenished, causing float valve core 101 to rise, increasing the cross-sectional area of ​​the passageway between water inlet 109 and drain outlet 108 and the flow rate. As a result, siphoning is maintained dynamically for a long period of time, eliminating the need for frequent activation of drain pump 2.

[0044] In a preferred solution, a threaded sleeve 102 is provided on the floating valve core 101 , and the rotating rod 104 is threadedly connected to the floating ball 103 .

[0045] The initial height of the floating valve core 101 and the height of the lowest end of the float ball 103 can be easily adjusted.

[0046] In a preferred solution, the drainage pipeline further includes one or more backup pumps 7 .

[0047] When a fault occurs and leakage increases suddenly, after the siphon is broken, the drainage pump 2 and the backup pump 7 work simultaneously to quickly pump out the accumulated water.

[0048] In a preferred solution, a second check valve 5 is further provided on the first branch, a first check valve 4 is further provided on the second branch, and a third check valve 6 is further provided on the ventilation branch.

[0049] Each check valve allows each branch to be connected to the main line in one direction, avoiding mutual influence between branches.

[0050] The second check valve 5 is spring-loaded and requires a certain amount of starting force. Since the siphon negative pressure is relatively small, the second check valve 5 cannot be opened and the first branch does not pump water.

[0051] Including control methods,

[0052] Drain pump 2 starts, draining the first branch;

[0053] After the air in the second branch is exhausted, the drainage pump 2 stops and the second branch siphons the water;

[0054] The flow regulating device 1 adaptively adjusts the opening size of the water inlet according to the water level in the top cover;

[0055] When the siphon drainage time reaches the specified value, the vacuum solenoid valve 3 opens, air enters the drainage pipe, and the siphon drainage is destroyed;

[0056] Wait for a certain period of time until the water level reaches a safe level, and then repeat steps S1-S4.

[0057] Example 2:

[0058] The drainage system consists of a submersible pump, a jet pump, and a siphon drainage device. The primary drainage method is the siphon drainage device. In the event of a large amount of water accumulation, the submersible pump will be activated. In more serious situations such as power outages or damage to multiple cover pumps, the jet pump will automatically activate. The jet pump is independent of power supply and can drain water using the negative pressure generated by high-speed water flow.

[0059] The self-stabilizing flow control device can be replaced by a modified float valve. When the water inlet is higher than the outlet and there's no air in the drainage line, the siphon effect ensures continuous water flow, even if a section of the line is higher than the inlet. The siphoning stops when air enters the pipe. The device's water inlet mechanism is a mechanical, automatic lifting mechanism that automatically closes the inlet when the water level drops and air doesn't enter, preventing air from entering. When the water level rises, the inlet automatically opens, allowing water to flow and ensuring the siphoning effect continues.

[0060] The control system needs to realize the following functions:

[0061] (1) The control system can control the self-stabilizing top cover drainage system and top cover pump by rising and falling the water level, so that the water level is always maintained at a safe level and no flooding or water diversion incidents occur;

[0062] (2) The control system can realize the rotation of water pumps;

[0063] (3) The control system can put all equipment into use to achieve emergency drainage in an emergency;

[0064] (4) Since the original water pump does not reach the starting water level after the self-stabilizing top cover drainage system is started and the starting conditions are not met, the control system needs to send a command to the self-stabilizing top cover drainage system to stop at regular intervals. After it stops, the water level will rise. After the water level rises, other drainage pumps are started to test their performance after a long period of non-startup.

[0065] By changing the start and stop water levels and installing vacuum solenoid valves and other devices, the automatic control of the multifunctional self-stabilizing roof drainage system is achieved. The basic process is as follows:

[0066] (1) Use the self-stabilizing top cover drainage device as the main operating mode. Install a vacuum solenoid valve at a higher position on the drainage pipe of the self-stabilizing top cover drainage device and connect the solenoid valve to the control system. After the submersible pump in the self-stabilizing top cover drainage device is started and the water pumping reaches the pump stop level, the self-stabilizing top cover drainage device automatically starts to operate. When the contactor is disconnected, the vacuum solenoid valve is activated, the vacuum degree is destroyed, and the self-stabilizing top cover drainage device stops operating.

[0067] (2) Two top cover drainage pumps are used as backup pumps and are started regularly to check whether the top cover drainage pumps are normal. After any pump stops operating for a certain period of time (such as 30 days), the vacuum solenoid valve is activated to start the 1# top cover drainage pump, 2# top cover drainage pump, and self-stabilizing top cover drainage device once in turn. After the self-stabilizing top cover drainage device is running, the self-stabilizing top cover drainage device automatically starts to operate. After the self-stabilizing top cover drainage device is automatically put into operation, the top cover water flow will continue to be discharged, so that the top cover water level will eventually remain at the maintenance water level.

[0068] (3) The opening conditions of the solenoid valve are as follows: Figure 3 As shown in the figure, n is a parameter configurable on the touchscreen. The vacuum solenoid valve's actuation command signal is sent via a communication point to the monitoring system's event log. If any pump is out of service for a specified period (e.g., n = 30 days), a signal is sent to the solenoid valve to energize it for approximately 30 seconds. This energization injects air into the system, disrupting the vacuum in the pipeline and halting drainage from the self-stabilizing top cover drain. After drainage ceases, rising water levels automatically trigger pump start / stop signals until the pump in the self-stabilizing top cover drain is restarted and drainage resumes.

[0069] Normal drainage systems cannot be black-started by setting up a UPS power supply because the water pumps run continuously. Since this system only needs to start for a short time before the pumps stop and stable gravity drainage is automatically achieved, setting up a UPS power supply can achieve continuous and stable drainage in the event of a power outage, greatly improving equipment reliability.

[0070] The above embodiments are merely preferred technical solutions of the present invention and should not be construed as limiting the present invention. The scope of protection of the present invention shall be the technical solutions set forth in the claims, including equivalent alternatives to the technical features of the technical solutions set forth in the claims. In other words, equivalent alternatives and improvements within this scope are also within the scope of protection of the present invention.

Claims

1. A self-stabilizing roof drainage system, characterized by: The invention comprises a drainage pipeline, wherein one end of the drainage pipeline is provided with a main drainage outlet, the other end of the drainage pipeline is provided with a first branch and a second branch connected in parallel, the first branch and the second branch are respectively provided with a first branch water inlet and a second branch water inlet, the height of the main drainage outlet is lower than the heights of the first branch water inlet and the second branch water inlet, the first branch is provided with a drainage pump (2), the second branch is provided with a flow regulating device (1), the drainage pipeline is further provided with a ventilation branch connected in parallel with the first branch and the second branch, and the ventilation branch is provided with a vacuum solenoid valve (3); The flow regulating device (1) comprises a cylinder, wherein a drain port (108) and a water inlet (109) are arranged opposite to each other on a side wall of the cylinder, a slidable floating valve core (101) is provided in the cylinder, a first gear (105) and a second gear (106) that mesh with each other are provided on the cylinder, a rotating rod (104) and a shifting rod (107) are also provided, wherein the two ends of the rotating rod (104) are respectively connected to the floating ball (103) and the first gear (105), one end of the shifting rod (107) shifts the floating valve core (101), and the other end of the shifting rod (107) is connected to the second gear (106), so that the height of the floating ball (103) changes so that the area of ​​the drain port (108) blocked by the floating valve core (101) changes.

2. The self-stabilizing roof drainage system according to claim 1, characterized in that: A screw sleeve (102) is provided on the floating valve core (101), and a rotating rod (104) is threadedly connected to a floating ball (103).

3. The self-stabilizing roof drainage system according to claim 1, characterized in that: The drainage line also includes one or more backup pumps (7).

4. The self-stabilizing roof drainage system according to claim 1, characterized in that: The first branch is further provided with a second check valve (5), the second branch is further provided with a first check valve (4), and the ventilation branch is further provided with a third check valve (6).

5. The control method of the self-stabilizing roof drainage system according to claim 1 is characterized by: S1, drainage pump (2) starts, and the first branch is drained; S2, after the air in the second branch is exhausted, the drainage pump (2) stops and the second branch siphons the water out; S3, the flow regulating device (1) adaptively adjusts the opening size of the water inlet according to the water level height in the top cover; S4, when the siphon drainage time reaches the specified value, the vacuum solenoid valve (3) opens, air enters the drainage pipe, and the siphon drainage is destroyed; S5. Wait for a certain period of time until the water level reaches a safe level, and then repeat steps S1-S4.

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