Water hammer wave blocker and blocking method for long-distance pressure water delivery pipeline

Abstract

The invention designs a water hammer wave blocker for a long-distance pressure pipeline water delivery system. The water hammer wave blocker comprises a water hammer wave blocking telescopic joint system, a vent hole telescopic joint system, a water hammer wave blocking telescopic joint storage system, a water hammer wave blocking telescopic joint system release and recovery system and a valve closing signal transmission system. The water hammer wave blocking expansion joint system is arranged in front of a valve at the tail end of a long-distance water conveying pipeline by a certain distance and can block water hammer waves from continuously spreading towards the upstream, so that pipelines above the water hammer wave blocking device and various matched pipeline facilities are prevented from being troubled by water hammer pressure; the measures for improving the pressure resistance level of the pipeline and improving the safety level of the pipeline facilities, which are additionally adopted for resisting the water hammer pressure, of the pipeline and the pipeline facilities can be omitted, the engineering cost is greatly reduced, and the engineering safety assurance rate is greatly increased.

Description

Technical Field

[0001] The invention relates to the field of water hammer protection for water supply pipeline systems, and in particular to a water hammer wave blocker and a blocking method for a long-distance pressurized water transmission pipeline. Background Art

[0002] Pipeline water hammer refers to the phenomenon of pressure waves caused by the inertia of liquid flow in the pipeline system, which usually occurs when the water flow suddenly stops or changes its flow direction. This pressure wave can cause vibration and damage to the pipeline system. In order to reduce or avoid pipeline water hammer, people usually adopt various methods, such as adding buffers, installing pressure reducing valves, changing the start and stop mode of water pumps, etc.

[0003] Water hammer pressure in long-distance water pipelines involves the pressure waves generated by the flow of liquid in the pipeline system and its control. In long-distance water pipelines, when the flow rate of the liquid changes suddenly (such as the sudden closing of a valve), pressure waves will be generated, which will cause water hammer, that is, the instantaneous high and low pressure fluctuations of the liquid in the pipeline. Pipeline water hammer may damage the pipeline system, so measures need to be taken to prevent water hammer pressure from causing damage to the pipeline system.

[0004] At present, the following technical routes are mainly used to prevent water hammer in long-distance water pipelines: 1. Buffer (water hammer absorbing device): Buffers are installed in the piping system to absorb the energy generated by water hammer and slow down the propagation and impact of pressure waves. The design and selection of buffers need to consider parameters such as pipeline diameter, working pressure, and flow rate.

[0005] 2. Install a pressure reducing valve: By installing a pressure reducing valve, the water pressure peak can be reduced and the increase in internal pressure in the pipeline can be limited, thereby reducing the impact of water hammer.

[0006] 3. Change the start and stop method of the water pump: Use soft start or soft stop to reduce the impact and pressure waves caused by the start and stop of the water pump, and reduce the risk of water hammer.

[0007] 4. Add valve buffer devices: Installing appropriate valve buffer devices on the pipeline can slow down water hammer and reduce pressure fluctuations in the pipeline system.

[0008] 5. Increase the design pressure of the pipeline: In the design process of long-distance water pipelines, increase the pressure level of the pipeline to ensure the safe operation of the pipeline under the action of water hammer pressure.

[0009] The above five technologies for reducing pipeline water hammer pressure cannot completely eliminate water hammer pressure, and most of them belong to passive protection, with low reliability and poor adaptability. Their effects cannot be reliably and effectively guaranteed. Therefore, in order to meet the safe operation guarantee rate in engineering design, it is usually necessary to calculate the water hammer pressure while adopting the above measures, and determine the pressure level of the pipeline and pipeline facilities according to the calculation results of the water hammer pressure.

[0010] Therefore, the current design of long-distance water pipelines usually takes water hammer pressure into account, which additionally increases the pressure level of the pipeline and the pressure level of the pipeline's supporting facilities. In order to deal with the water hammer pressure, the project cost increases significantly. Summary of the invention

[0011] Purpose of the invention: In order to solve the problem of safe water delivery in long-distance water delivery pipelines, the present invention provides a blocker that can effectively block the propagation of water hammer waves and water hammer pressure.

[0012] Technical solution: To solve the above technical problems, the present invention provides a long-distance pressurized water pipeline water hammer wave blocker, including a water hammer wave blocking expansion joint system, a vent expansion joint system, a water hammer wave blocking expansion joint storage system, a water hammer wave blocking expansion joint system release and recovery system and a valve closing signal transmission system; The water hammer wave blocking expansion joint system can be raised and lowered in the water hammer wave blocking expansion joint storage system and is connected to the vent expansion joint system. The valve closing signal transmission system is used to transmit control instructions. The water hammer wave blocking expansion joint system release and recovery system is used to execute control instructions and drive the water hammer wave blocking expansion joint system to perform lifting preparation or falling work.

[0013] Specifically, the water hammer wave blocking expansion joint system comprises an upstream wall of the expansion joint, an inner sleeve of the expansion joint, a pressure-bearing spring, a positioning pull rope, an outer sleeve of the expansion joint, a downstream wall of the expansion joint and a vent hole; The right side of the upstream wall of the telescopic joint is connected to the inner sleeve of the telescopic joint, and the inner sleeve of the telescopic joint is sleeved in the outer sleeve of the telescopic joint, and a pressure spring and a positioning rope are installed between the two. The downstream wall of the telescopic joint serves as a lifting gate to separate the upstream and downstream water bodies when falling; When the expansion joint is in the falling working state, the pressure-bearing spring bears the water hammer pressure transmitted from the upstream wall of the expansion joint, and in the preparation for lifting, the water hammer pressure is blocked to restore the expansion joint system to the designed length and is limited by the positioning rope; The vent hole is located at the top of the expansion joint outer sleeve near the downstream wall of the expansion joint, and the expansion joint communicates the compressible volume between the inner and outer sleeves of the expansion joint with the external atmosphere through the vent hole. It also includes a positioning rolling ball, a waterproof rubber ring and a counterweight; The positioning rolling ball is arranged at the position where the inner side of the outer sleeve of the telescopic joint overlaps with the inner sleeve of the telescopic joint. When the telescopic joint is extended or retracted, the positioning rolling ball plays a role in stabilizing the positions of the inner and outer sleeves and reducing friction. The waterproof rubber ring is attached to the inner sleeve and the outer sleeve of the telescopic joint to prevent water from entering the telescopic joint. The left end of the waterproof rubber ring is adhered to the outer wall of the left end of the inner sleeve of the telescopic joint, and the right end is adhered to the outer wall of the left end of the outer sleeve of the telescopic joint at a certain distance. The middle section of the waterproof rubber ring is freely attached to the outer walls of the inner sleeve and the outer sleeve of the telescopic joint. The counterweight is arranged on the inner wall of the water hammer wave blocking expansion joint, so that the weight of the water hammer wave blocking expansion joint is greater than the buoyancy it receives.

[0014] Specifically, the vent expansion joint system includes a vent expansion joint inner sleeve and a vent expansion joint outer sleeve, the vent expansion joint inner sleeve is a tube body connected to the vent at the bottom, and its top passes through the water hammer wave blocking expansion joint storage system and is connected to the external space, and is connected to the water hammer wave blocking expansion joint release spring and the release spring tightening wire rope; the vent expansion joint outer sleeve is a steel pipe fixedly connected to the inner side of the top plate of the water hammer wave blocking expansion joint storage system.

[0015] Specifically, it also includes a waterproof rubber ring, the lower end of the waterproof rubber ring is adhered to the outer wall of the lower end of the inner sleeve of the vent expansion joint, and the upper end is adhered to the outer wall of the lower end of the outer sleeve of the expansion joint at a certain distance.

[0016] Specifically, the water hammer wave blocking expansion joint storage system has a closed space. When the water hammer wave blocking expansion joint is in a non-working state, it is lifted and prepared to the upper space of the storage system; when the water hammer wave blocking expansion joint falls to work, it moves down from the upper space of the storage system to the lower working position.

[0017] Specifically, the water hammer wave blocking expansion joint release and recovery system is used to release and recover the water hammer wave blocking expansion joint system, including a frame column, a frame beam, a vent pipe positioning ring, a spring, a wire rope, a wire rope drum, a wire rope drum electromagnetic switch positioner, a wire rope drum gear plate and an electric motor.

[0018] Specifically, the valve closing signal transmission system includes a wired system and a wireless system. When the valve at the end of the pipeline is closed, the signal is transmitted to the wire rope drum electromagnetic switch positioner signal receiver through the wired system and the wireless system at the same time. When the signal receiver receives the signal, the electromagnetic switch is instantly turned on, and the positioner is separated from the wire rope drum bearing, so that the wire rope drum releases a water hammer wave to block the expansion joint system from falling.

[0019] The present invention also provides a method for blocking water hammer waves in a long-distance pressurized water transmission pipeline. A water hammer wave blocking expansion joint system is arranged in a liftable manner in a water hammer wave blocking expansion joint storage system and is connected to a vent expansion joint system. When a valve at the end of the pipeline is closed, the valve closing signal transmission system transmits a control instruction to control a water hammer wave blocking expansion joint release and recovery system to release the water hammer wave blocking expansion joint system to fall. The water hammer wave blocking expansion joint system separates upstream and downstream water bodies and absorbs water hammer waves at the same time.

[0020] Principle of the invention: A water hammer (wave) pressure blocker is set at a certain distance before the end valve of a long-distance water transmission pipeline to block the water hammer (wave) pressure, so that the water hammer pressure stops at the water hammer (wave) pressure blocker and no longer propagates to the upstream pipeline.

[0021] The water hammer arrester adopts a liftable structure, which can absorb water hammer waves and isolate the upstream and downstream water bodies at the same time.

[0022] Beneficial effects: The present invention blocks the water hammer wave from continuing to propagate upstream by setting a water hammer blocker on the pipeline, so that the pipeline above the water hammer blocker and various supporting pipeline facilities are free from the trouble of water hammer pressure, and can reduce the additional measures taken by the pipeline and pipeline facilities to improve the pipeline pressure resistance level and improve the safety level of the pipeline facilities to resist water hammer pressure, greatly reduce the project cost, and greatly improve the project safety guarantee rate. This completely solves the problem of water hammer pressure that has long plagued long-distance pressurized water pipelines. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a schematic diagram of the positions of valves and water hammer wave arresters on a long-distance water pipeline according to Example 1 of the present invention.

[0024] Figure 2 This Figure 1 Schematic diagram of the water hammer arrester in the falling (working) state.

[0025] Figure 3 yes Figure 2 Schematic diagram in the raised (ready) state.

[0026] Figure 4 yes Figure 3 AA cross-section diagram.

[0027] Figure 5 yes Figure 2 AA cross-section diagram.

[0028] Figure 6 yes Figure 3 BB cross-section diagram.

[0029] Figure 7 yes Figure 2 BB cross-section diagram.

[0030] Figure 8 yes Figure 2 Schematic diagram of a water hammer arrester.

[0031] Fig. 9 yes Figure 3 CC cross-section diagram.

[0032] Fig.10 yes Figure 2 CC cross-section diagram.

[0033] Fig.11 Schematic diagram of a preliminary water hammer pressure verification experimental platform according to Example 2 of the present invention.

[0034] Fig.12 Q = 19.38m 3 / h when water hammer pressure changes with time.

[0035] Fig.13 Q = 25.58m 3 / h when water hammer pressure changes with time.

[0036] Fig.14 Q = 31.69m 3 / h when water hammer pressure changes with time.

[0037] Fig.15 Q = 37.70m 3 / h when water hammer pressure changes with time. DETAILED DESCRIPTION

[0038] Example 1 In this implementation, valves and water hammer wave interrupters are arranged on long-distance pressurized water pipelines. The arrangement positions are as follows: Figure 1 As shown, a water hammer wave blocker 3 is arranged at a position 1200 meters away from the water hammer wave direction of the end valve to separate the upstream pipeline, a wireless signal transmitter W1 is arranged at the valve 6 at the end of the pipeline, and a wireless signal receiver W2 is arranged at the water hammer wave blocker, and they are connected by a wired signal transmission line. The arrow in the figure represents the direction of the water hammer wave, and the end section is the upstream pipeline 10.

[0039] like Figure 2-Figure 9 As shown, it mainly includes a water hammer pressure blocking expansion joint system 3.1, a vent expansion joint system 3.2, a water hammer pressure blocking expansion joint storage system 3.3, a water hammer pressure blocking expansion joint release recovery system 3.4 and a valve closing signal transmission system, wherein: 3.1 Water hammer wave blocking expansion joint system The water hammer wave blocking expansion joint system 3.1 is composed of an expansion joint downstream wall 3.1.2, an expansion joint upstream wall 3.1.1, an expansion joint outer sleeve, an expansion joint inner sleeve, a positioning rolling ball, a waterproof rubber ring, a pressure spring, a positioning pull rope, a vent, and a counterweight.

[0040] (1) Downstream wall of expansion joint 3.1.2 The downstream wall of the expansion joint is a steel plate with a diameter slightly larger than the pipe diameter, and its left side is connected to the outer sleeve of the expansion joint. The part below the center of the downstream wall of the expansion joint is semicircular, with a diameter slightly larger than the pipe diameter, and the part above the center is rectangular, with a width slightly larger than the pipe diameter and the same as the diameter of the downstream wall of the expansion joint.

[0041] The width and diameter of the downstream wall of the expansion joint are slightly larger than the pipe diameter. When rising and falling, the part larger than the pipe diameter is stuck in the slot on the side wall of the blocker storage system, and moves up and down along the slot, playing a positioning role during lifting and lowering. The lower half of the water hammer wave blocking expansion joint storage system is semicircular, and at the contact point with the downstream wall of the expansion joint, there is a slot similar to the side wall. When the water hammer wave blocking expansion joint falls to the working position, the semicircle of the downstream wall of the water hammer wave blocking expansion joint is stuck in the semicircular slot of the lower half of the water hammer wave blocking expansion joint storage system, playing a role in positioning and supporting the pressure on the left side.

[0042] The water hammer wave blocks the upper semi-rectangular part of the downstream wall of the expansion joint, and its height is greater than the radius of the pipe.

[0043] A circle of closed rubber pad is fixed around the downstream side of the downstream wall of the expansion joint. When the water hammer wave blocking expansion joint falls to the working position, the rubber pad fits against the downstream wall of the side wall slot of the blocker storage system. When the upstream water hammer pressure is transmitted through the water hammer wave blocking expansion joint, the rubber pad is pressed against the downstream wall of the side wall slot of the blocker storage system, thereby sealing and stopping water, and separating the downstream water body from the upstream pipeline 10.

[0044] (2) Upstream wall of expansion joint 3.1.1 The upstream wall of the expansion joint is a steel plate with a diameter slightly smaller than the pipe diameter, and its right side is connected to the inner sleeve of the expansion joint. The upstream wall of the expansion joint is circular, and its diameter is slightly smaller than the pipe diameter.

[0045] (3) Outer sleeve of expansion joint The outer sleeve of the expansion joint is a steel structure with an outer diameter the same as the inner diameter of the pipe. Its right end is connected to the downstream wall of the expansion joint, and the left end is a certain distance away from the upstream wall of the expansion joint to meet the expansion distance requirements when subjected to water hammer pressure.

[0046] The outer sleeve of the telescopic joint overlaps with the inner sleeve of the telescopic joint, and a number of positioning rolling balls are embedded on the inner side of the outer sleeve of the telescopic joint, which play a role in reducing resistance when the telescopic joint is telescoped and extending, and play a role in fixing the outer sleeve of the telescopic joint and the inner sleeve of the telescopic joint to ensure relatively stable operation.

[0047] (4) Telescopic joint inner sleeve The inner sleeve of the expansion joint is a steel structure, the left end of which is connected to the upstream wall of the expansion joint, and the outer diameter of which is the distance between the inner surface of the outer sleeve of the expansion joint and the embedded ball surface. That is, its outer surface contacts the embedded ball on the inner surface of the outer sleeve of the expansion joint.

[0048] (5) Positioning rolling ball A number of rolling balls are arranged at the part where the inner side of the outer sleeve of the telescopic joint overlaps with the inner sleeve of the telescopic joint. Half of the balls are embedded and fixed in the wall of the outer sleeve of the telescopic joint, and the other half are exposed outside the wall. The top surface of the positioning balls exposed outside the wall contacts the outer wall of the inner sleeve of the telescopic joint. When the telescopic joint is extended or retracted, the positioning rolling balls play a role in stabilizing the position of the inner and outer sleeves and reducing friction.

[0049] (6) Waterproof rubber ring The waterproof rubber ring is attached to the inner sleeve and the outer sleeve of the expansion joint to prevent water from entering the expansion joint.

[0050] The left end of the waterproof rubber ring is adhered to the outer wall of the left end of the inner sleeve of the expansion joint, and the right end is adhered to the outer wall of the left end of the outer sleeve of the expansion joint at a certain distance.

[0051] The middle section of the waterproof rubber ring fits freely on the outer walls of the inner sleeve and the outer sleeve of the expansion joint. In the gap where the inner sleeve and the outer sleeve of the expansion joint overlap, the waterproof rubber ring is in a long "U" shape and has a certain length. It fits on the outer walls of the inner sleeve and the outer sleeve of the expansion joint, meeting the relative expansion and contraction distance requirements when the expansion joint is working.

[0052] (7) Pressure spring The pressure-bearing spring is located at the center of the axis of the telescopic joint and is connected to the downstream wall and the upstream wall of the telescopic joint through a rubber pad.

[0053] When the expansion joint is not in operation, the pressure-bearing spring bears the water pressure transmitted by the upstream and downstream walls of the expansion joint, and keeps the expansion joint at the designed length under the maximum pressure condition without bearing the water hammer pressure.

[0054] (8) Positioning rope The positioning pull rope is a steel wire rope, which is located at the center of the axis of the expansion joint and is connected to the downstream wall and the upstream wall of the expansion joint.

[0055] The positioning rope keeps the expansion joint at the longest design length when it is not subjected to water hammer pressure. If the water pressure in the pipeline decreases, the water pressure on the expansion joint also decreases, and the pressure spring will push the expansion joint out. At this time, the positioning rope is used to hold the expansion joint, so that the expansion joint is always kept at the longest design length.

[0056] (9) Ventilation port The vent is located at the top of the expansion joint outer sleeve near the downstream wall of the expansion joint, and is connected to the vent expansion joint, so that the inside of the expansion joint is connected to the external atmosphere.

[0057] (10) Counterweight A counterweight block is arranged on the inner wall of the water hammer wave blocking expansion joint, so that the weight of the water hammer wave blocking expansion joint is much greater than the buoyancy it receives, thereby making it easier for the water hammer wave blocking expansion joint to quickly reach the working position and reducing the working pressure of the water hammer wave blocking expansion joint release spring.

[0058] 3.2 Vent expansion joint system The vent expansion joint system 3.2 is composed of an expansion joint inner sleeve, an expansion joint outer sleeve, and a waterproof rubber ring.

[0059] (1) Vent expansion joint inner sleeve The inner sleeve of the vent expansion joint is a steel pipe, and the bottom is connected to the expansion joint vent of the "water hammer wave blocking expansion joint system". The top is connected to the outside of the top plate of the "water hammer wave blocking expansion joint storage system" and is connected to the external space.

[0060] The top of the inner sleeve of the vent hole expansion joint is connected with the water hammer wave blocking expansion joint release spring and the release spring tightening wire rope.

[0061] (2) Vent hole expansion joint outer sleeve The outer sleeve of the vent expansion joint is a steel pipe, and the top is connected to the inner side of the top plate of the "water hammer wave blocking expansion joint storage system". The lower part is a suspended end, and its length is greater than 1 / 2 of the pipe diameter.

[0062] When the "water hammer wave blocking expansion joint system" is in a non-working state, its lower part is at a certain distance from the expansion joint outer sleeve of the "water hammer wave blocking expansion joint system", which is convenient for the installation and operation of the waterproof rubber ring of the vent hole expansion joint.

[0063] (3) Waterproof rubber ring The waterproof rubber ring is attached to the inner sleeve and the outer sleeve of the vent expansion joint to prevent water from entering the expansion joint.

[0064] The lower end of the waterproof rubber ring is adhered to the outer wall of the lower end of the inner sleeve of the vent expansion joint, and the upper end is adhered to the outer wall of the lower end of the outer sleeve of the expansion joint at a certain distance.

[0065] The middle section of the waterproof rubber ring is freely attached to the outer wall of the inner sleeve and the outer wall of the outer sleeve of the vent expansion joint. In the gap where the inner sleeve and the outer sleeve of the expansion joint overlap, the waterproof rubber ring is in a long "U" shape, with the same length as the outer sleeve. It fits to the outer wall of the inner sleeve and the inner wall of the outer sleeve of the expansion joint, meeting the relative expansion and contraction distance requirements when the expansion joint is working.

[0066] 3.3 Water hammer wave blocking expansion joint storage system The water hammer wave blocking expansion joint storage system is a closed space and a steel structure. When the water hammer wave blocking expansion joint is not in working state, it is located in the upper space of the storage system; when the water hammer wave blocking expansion joint is working, it moves down from the upper space of the storage system to the lower working position.

[0067] (1) System shape The lower part of the system cross section is semicircular, with the inner diameter being the same as the inner diameter of the pipe, and the upper part is rectangular.

[0068] The length of the system is greater than the length of the water hammer wave blocking expansion joint, and a part of space is left on the left side of the water hammer wave blocking expansion joint. When the water hammer wave blocking expansion joint moves down from the upper space of the storage system to the lower working position, the water flow is displaced inside the water hammer wave blocking expansion joint storage system.

[0069] (2) Positioning slot A groove is provided at the end of the side wall of the water hammer wave blocking expansion joint storage system, and a groove is also provided at the corresponding lower semicircular section. The downstream wall plate of the water hammer wave blocking expansion joint is stuck in the groove, so that the water hammer wave blocking expansion joint moves up and down along the groove. When the water hammer wave blocking expansion joint is in the lower working position, the groove plays a role in supporting the water hammer wave blocking expansion joint to support the water hammer pressure transmitted from the water hammer wave blocking expansion joint.

[0070] (3) Upper hole A hole corresponding to the vent hole of the water hammer wave blocking expansion joint is arranged on the right side of the top plate of the water hammer wave blocking expansion joint storage system, and the hole is connected to the upper end of the outer sleeve of the vent hole expansion joint.

[0071] 3.4 Water hammer wave blocking expansion joint release and recovery system The water hammer wave blocking expansion joint release and recovery system is used to release and recover the water hammer wave blocking expansion joint.

[0072] The system consists of frame columns, frame beams, ventilation pipe positioning rings, springs, wire ropes, wire rope drums, wire rope drum electromagnetic switch positioners, wire rope drum gear plates, motors, etc.

[0073] (1) Frame columns and frame beams The frame columns and frame beams are the supporting platforms for the wire rope drum.

[0074] The lower part of the frame column is fixed on the top plate of the water hammer wave blocking expansion joint storage system.

[0075] The frame beam is located at the upper end of the frame column and is used to fix the wire rope drum system.

[0076] (2) Ventilation pipe positioning ring The inner sleeve of the vent expansion joint system passes through the hole of the top plate of the water hammer wave blocking expansion joint storage system.

[0077] The vent pipe positioning ring is fixed on the top plate of the water hammer wave blocking expansion joint storage system. Its inner diameter is slightly larger than the outer diameter of the inner sleeve of the vent hole expansion joint system. When the inner sleeve of the vent hole expansion joint system moves up and down, it plays a role in supporting positioning and reducing friction.

[0078] (3) Spring The upper end of the spring is fixed on the frame beam, and the lower end is fixed on the top end of the sleeve in the vent expansion joint system.

[0079] When the water hammer wave blocking expansion joint is in a non-working (to be released) state, the spring is in a compressed state.

[0080] When the water hammer wave blocking expansion joint needs to be released, the elastic force is released by the spring, and the elastic force bounces the water hammer wave blocking expansion joint downward to the working position through the inner sleeve of the vent expansion joint system.

[0081] (4) Wire rope The lower end of the steel wire rope is fixed to the top of the inner sleeve of the vent expansion joint system, and the upper end is wound on the steel wire rope drum.

[0082] When the water hammer wave blocking expansion joint needs to be retracted, the wire rope is shortened by rotating the drum, and the spring is compressed and shortened accordingly until it returns to its original position.

[0083] (5) Wire rope drum The wire rope drum is fixed on the frame beam and is used to wind the wire rope to loosen and tighten the wire rope.

[0084] (6) Wire rope drum electromagnetic switch positioner The electromagnetic switch positioner of the wire rope drum is located at one end of the wire rope drum bearing and is used to lock the bearing to prevent the wire rope drum from rotating.

[0085] When it is necessary to release the water hammer wave to block the expansion joint to the working position, the electromagnetic switch positioner of the wire rope drum opens, allowing the wire rope drum to rotate freely.

[0086] (7) Wire rope drum gear plate The wire rope drum gear disc is located at the other end of the wire rope drum bearing and meshes with the motor gear.

[0087] (8) Electric motor The electric motor is connected to the motor gear.

[0088] When the water hammer wave blocking expansion joint needs to be retracted from the working position, the motor drives the gear to rotate, and the wire rope drum rotates accordingly, tightening the wire rope, and the spring is compressed and shortened until it returns to the original position.

[0089] Valve closing signal transmission system The valve closing signal transmission system consists of a wired system and a wireless system. The two systems work simultaneously to improve the signal transmission guarantee rate.

[0090] When the valve at the end of the pipeline is closed, the signal is transmitted to the wire rope drum electromagnetic switch positioner signal receiver through the wired system and the wireless system at the same time. When the signal receiver receives the signal, the electromagnetic switch is instantly opened, and the positioner is separated from the wire rope drum bearing, so that the wire rope drum can rotate freely.

[0091] Embodiment 2: In a pressurized water pipeline, when the valve at the end of the pipeline is suddenly closed or opened, the liquid flow rate will suddenly decrease or increase, and the kinetic energy will be instantly converted into pressure energy, forming a pressure wave that oscillates and transmits periodically along the pipeline, and water hammer occurs. Pipeline water hammer may seriously damage the pipeline system, so measures need to be taken to prevent instantaneous high and low pressure fluctuations of the liquid in the pipeline from causing damage to the pipeline system. How to effectively block the water hammer pressure generated by the water hammer wave is an important aspect of maintaining safe water delivery in long-distance water pipelines. The present invention can block the water hammer (wave) pressure, so that the water hammer (wave) pressure stops at the water hammer (wave) pressure blocker and no longer propagates to the upstream pipeline. In order to verify the blocking effect, the inventor applied this technology to conduct a blocking test of pipeline water hammer (wave) pressure transmission.

[0092] Build a test platform for water hammer arrester to block the transmission of water hammer pressure wave, such as Fig.11 This embodiment is only used to verify the working state of the telescopic joint, so no lifting system is set, and the vent holes are arranged horizontally.

[0093] The horizontal pipe section of the platform is composed of two transparent PVC pipes with a length of 3m, an inner diameter of 100mm and a wall thickness of 5mm. A pressure water injection pipe of the same size is connected to the junction of the two pipes, and a submersible electric pump is connected to the upstream of the water injection pipe. The submersible electric pump model is WQ60-7-3, that is, the rated flow rate is 60m 3 / h, rated lift 7m and power 3kw.

[0094] In the figure, 1 is the pipeline inlet, 2 is the horizontal pipeline, 3 is the water hammer wave blocker, pressure sensor CH1, pressure sensor CH2, 6 is the downstream tail end ball valve, 7 is the upstream connection flange of the blocker, 8 is the end flange and blind plate of the upstream pipeline of the blocker, 9 is the vent, and 10 is the upstream pipeline. Water is pumped into pipeline 1 from the submersible pump at the head and flows into the horizontal pipeline 2. After that, the water flows continuously from the inlet and flows from right to left along the horizontal pipeline. The end 6 ball valve is used to control the pipeline flow. The upstream of the blocker is connected to a 25cm long pipeline of the same diameter through a flange. A high-precision pressure sensor is installed on this pipe section, represented by CH2. The upstream pipeline end of the blocker is sealed with a flange and a blind plate. Rubber water stops are set between the flange and the blind plate to prevent water leakage. The entire system has only one inlet 1 and one outlet 6. A high-precision pressure sensor is installed 40cm downstream of the blocker, represented by CH1. The pressure sensor model is DY2010, which is used to collect real-time pressure change data in the pipeline, with a measurement range of -0.1MPa to 1MPa, a sampling interval of 1ms, and a sampling accuracy of ±0.1% FS. In addition, the pipeline flow is measured by an electromagnetic flowmeter of model LD-TDS, with an accuracy of 1% and a range of DN15-6000mm. At the same time, a rectangular water-measuring thin-wall weir is used downstream of the system for flow calibration. The pipeline flow is adjusted by the frequency converter adapted to the submersible pump itself.

[0095] The blocking test process of pipeline water hammer (wave) pressure transmission is as follows: start the submersible pump to inject water into the test system, first adjust the ball valve opening to a small degree, slowly inject water into the pipeline, and exhaust the pipeline system. When the upstream and downstream pipes of the blocker are full of liquid and there is no gas cavity, the ball valve is fully opened and a constant flow state is maintained. The flow reading of the submersible pump inverter, the ultrasonic electromagnetic flowmeter display reading, and the downstream rectangular thin-walled water measuring weir probe reading are recorded, the flow is calibrated, and the data is recorded. When the flow is constant, the blocker remains stationary, and the values ​​of sensors CH1 and CH2 upstream and downstream of the blocker are almost equal. After that, the ball valve at the downstream end of the pipeline is instantly closed, and a valve-closing water hammer (wave) is instantly generated at the valve in the pipeline and transmitted upstream to the blocker. The expansion and contraction changes of the water hammer (wave) pressure blocker are observed, and the changes in the pressure in the pipe at the upstream and downstream pressure data collection points of the blocker are monitored and recorded.

[0096] According to the above test process, in order to verify the actual blocking effect of this patented technology on water hammer waves, four groups of water hammer blocking effect tests were carried out under different flow rates and ball valve instantaneous closing conditions. The four groups of flow rates are: 19.38m 3 / h、25.58m 3 / h、31.69m 3 / h、37.70m 3 / h. Figure 12-Figure 15 shown.

[0097] The blocking rates of the water hammer blocker at each flow rate are listed in Table 1. The calculation formula for the blocking rate of the water hammer blocker is shown in Formula (1). As can be seen from the table, by comparing the pressure data collected by the pressure sensors upstream and downstream of the blocker at each flow rate, it can be clearly concluded that the water hammer (wave) is almost completely cut off by the blocker and stops propagating further upstream in the pipeline. The test results show that the effect of the present invention in blocking the water hammer (wave) in the pipeline is very ideal, achieving the expected concept of the invention.

[0098] (1) Wherein, η1 is the blocking rate of the water hammer arrester; PCH1 is the pressure downstream of the arrester; PCH2 is the pressure upstream of the arrester.

[0099] Table 1 Comparison of measured pressures of CH1 and CH2

[0100] The test found that the water hammer blocker not only has the function of blocking the water hammer wave from transmitting upstream, but also can significantly reduce the peak water hammer pressure in the pipe where the water hammer occurs. In order to further illustrate the effect of the water hammer blocker in eliminating water hammer pressure, the flow rate is calculated according to the direct water hammer pressure calculation formula (2) and (3). 3 / h、25.58m 3 / h、31.69m 3 / h、37.70m 3 / h, the direct water hammer pressure value when the valve is closed instantaneously without a blocker in the pipeline is compared with the value of the CH1 pressure sensor upstream of the blocker when water hammer occurs at the same flow rate after the water hammer blocker is installed. The results are shown in Table 2. It can be seen from the table that at each flow rate, without a blocker, the pressure peaks when direct water hammer occurs reach 242.92kPa, 320.72kPa, 397.29kPa, and 472.72kPa, while after the blocker is installed, the pressure peaks are reduced by 72.51%, 64.80%, 56.93%, and 43.62%, respectively. It is further proved that the installation of a water hammer (wave) blocker can not only block the propagation of water hammer waves upstream, but also largely eliminate the water hammer pressure peak of the water hammer pipeline.

[0101] (2) (3) Wherein, ∆H is the pressure head, m; c is the water hammer wave velocity, which is 357.694, m / s; g is the acceleration of gravity, 9.8m / s²; ∆v is the velocity change value, m / s; ρ is the density of water, which is 1000 kg / m³; P is the water hammer pressure, Pa.

[0102] The calculation formula of the reduction rate is as follows: (4) Among them, η2 is the water hammer interrupter reduction rate; P1 is the calculated value of direct water hammer pressure; PCH1 is the pressure downstream of the interrupter.

[0103] Table 2 Comparison of calculated and measured direct water hammer pressure values Example

[0105] In actual engineering applications, the vent of the water hammer wave blocking expansion joint is connected to the external atmosphere and is in a standard air pressure state. The pipeline diameter is 1.0m, and the hydrostatic pressure at the pipeline valve and the water hammer wave blocking device is the same, which is 0.5MPa. The water flow velocity in the pipeline is 2m / s. The length of the water hammer wave blocking expansion joint is 1.3m, and the diameter of the upstream wall is 0.996m, which is slightly smaller than the inner diameter of the pipeline. The spring force in the water hammer wave blocking expansion joint is the difference between the water pressure acting on the upstream wall and the atmospheric pressure inside the water hammer wave blocking expansion joint, which is 31.14t.

[0106] The water hammer arrester is located 1200m upstream of the end valve.

[0107] The end valve is closed. At the moment of closing, the water hammer wave propagates upstream at a speed of 1000m / s. At the same time, the valve closing signal is transmitted by the signal transmission system to the signal receiver of the wire rope drum electromagnetic switch positioner, which instantly opens the electromagnetic switch, and the blocker releases the spring to spring open. Within 1s, the water hammer wave blocking expansion joint is pushed to the working position, that is, the attached Figure 2 State. When the water hammer wave blocking expansion joint reaches the working position, the water hammer wave arrives later and acts on the upstream wall of the water hammer wave blocking expansion joint. The upstream wall of the expansion joint drives the sleeve inside the expansion joint to move to the right, thereby eliminating the water hammer pressure from propagating to the upstream pipeline, and the water hammer wave is also transmitted to the external space through the vent hole, thereby blocking the water hammer pressure. As a result, there is no water hammer pressure and water hammer wave in the upstream pipeline.

Claims

1. A water hammer wave arrester for a long-distance pressurized water pipeline, characterized in that: It includes a water hammer wave blocking expansion joint system, a vent hole expansion joint system, a water hammer wave blocking expansion joint storage system, a water hammer wave blocking expansion joint system release and recovery system, and a valve closing signal transmission system; The water hammer wave blocking expansion joint system can be raised and lowered in the water hammer wave blocking expansion joint storage system and is connected to the vent expansion joint system. The valve closing signal transmission system is used to transmit control instructions. The water hammer wave blocking expansion joint system release and recovery system is used to execute control instructions and drive the water hammer wave blocking expansion joint system release and recovery system to perform lifting preparation or falling work.

2. The water hammer wave arrester for long-distance pressurized water pipeline according to claim 1 is characterized by: The water hammer wave blocking expansion joint system comprises an upstream wall of the expansion joint, an inner sleeve of the expansion joint, a pressure-bearing spring, a positioning pull rope, an outer sleeve of the expansion joint, a downstream wall of the expansion joint and a vent hole; The right side of the upstream wall of the telescopic joint is connected to the inner sleeve of the telescopic joint, and the inner sleeve of the telescopic joint is sleeved in the outer sleeve of the telescopic joint, and a pressure spring and a positioning rope are installed between the two. The downstream wall of the telescopic joint serves as a lifting gate to separate the upstream and downstream water bodies when falling; The pressure-bearing spring bears the water hammer pressure transmitted from the upstream wall of the expansion joint when the expansion joint is in the falling operation, and blocks the water hammer wave when the expansion joint system is ready for lifting to restore to the designed length and is limited by the positioning rope; The vent hole is located at the top of the outer sleeve of the expansion joint close to the downstream wall of the expansion joint. The expansion joint communicates the compressible volume between the inner and outer sleeves of the expansion joint with the external atmosphere through the vent hole.

3. The water hammer wave arrester for long-distance pressurized water pipeline according to claim 2 is characterized by: It also includes positioning rolling balls, waterproof rubber rings and counterweights; The positioning rolling ball is arranged at the position where the inner side of the outer sleeve of the telescopic joint overlaps with the inner sleeve of the telescopic joint. When the telescopic joint is extended or retracted, the positioning rolling ball plays a role in stabilizing the positions of the inner and outer sleeves and reducing friction. The waterproof rubber ring is attached to the inner sleeve and the outer sleeve of the telescopic joint to prevent water from entering the telescopic joint. The left end of the waterproof rubber ring is adhered to the outer wall of the left end of the inner sleeve of the telescopic joint, and the right end is adhered to the outer wall of the left end of the outer sleeve of the telescopic joint at a certain distance. The middle section of the waterproof rubber ring is freely attached to the outer walls of the inner sleeve and the outer sleeve of the telescopic joint. The counterweight is arranged on the inner wall of the water hammer wave blocking expansion joint, so that the weight of the water hammer wave blocking expansion joint is greater than the buoyancy it receives.

4. The water hammer wave arrester for long-distance pressurized water pipeline according to claim 2 is characterized by: The vent expansion joint system includes a vent expansion joint inner sleeve and a vent expansion joint outer sleeve. The vent expansion joint inner sleeve is a tube body connected to the vent at the bottom, and its top passes through the water hammer wave blocking expansion joint storage system and is connected to the external space, and is connected to the water hammer wave blocking expansion joint release spring and the release spring tightening wire rope; the vent expansion joint outer sleeve is a steel pipe fixedly connected to the inner side of the top plate of the water hammer wave blocking expansion joint storage system.

5. The water hammer wave arrester for long-distance pressurized water pipeline according to claim 4 is characterized by: It also includes a waterproof rubber ring, the lower end of which is adhered to the outer wall of the lower end of the inner sleeve of the vent expansion joint, and the upper end is adhered to the outer wall of the lower end of the outer sleeve of the expansion joint at a certain distance.

6. The water hammer wave arrester for long-distance pressurized water pipeline according to claim 2, characterized in that: The water hammer wave blocking expansion joint storage system has a closed space. When the water hammer wave blocking expansion joint is in a non-working state, it is lifted and prepared to be in the upper space of the storage system; when the water hammer wave blocking expansion joint falls to work, it moves down from the upper space of the storage system to the lower working position.

7. The water hammer wave arrester for long-distance pressurized water pipeline according to claim 2 is characterized by: The water hammer wave blocking expansion joint release and recovery system is used for releasing and recovering the water hammer wave blocking expansion joint system, and comprises a frame column, a frame beam, a vent pipe positioning ring, a spring, a steel wire rope, a steel wire rope drum, a steel wire rope drum electromagnetic switch positioner, a steel wire rope drum gear plate and a motor.

8. The water hammer wave arrester for long-distance pressurized water pipeline according to claim 2 is characterized by: The valve closing signal transmission system includes a wired system and a wireless system. When the valve at the end of the pipeline is closed, the signal is transmitted to the wire rope drum electromagnetic switch positioner signal receiver through the wired system and the wireless system at the same time. When the signal receiver receives the signal, the electromagnetic switch is instantly turned on, and the positioner is separated from the wire rope drum bearing, so that the wire rope drum releases a water hammer wave to block the expansion joint system from falling.

9. A method for blocking water hammer waves in a long-distance pressurized water pipeline, characterized in that: The water hammer wave blocking expansion joint system is arranged in a liftable manner in the water hammer wave blocking expansion joint storage system and is connected with the vent expansion joint system. When the valve at the end of the pipeline is closed, the valve closing signal transmission system transmits a control instruction to control the water hammer wave blocking expansion joint release and recovery system to release the water hammer wave blocking expansion joint system to fall. The water hammer wave blocking expansion joint system separates the upstream and downstream water bodies and absorbs the water hammer wave at the same time.

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