A temperature control system for the thrust bearing of a steam-driven feedwater pump

Abstract

This invention belongs to the field of steam-driven feedwater pump technology, specifically a temperature control system for the thrust bearing of a steam-driven feedwater pump. The system includes a pump body with an inlet pipe, an outlet pipe, and a balance water pipe. The balance water pipe is connected at both ends to the internal cavity of the pump body and is connected in parallel to the outside of the pump body, ensuring that the feedwater in the pump body cavity flows smoothly back into the inlet pipe. A flow regulating device is installed on the surface of the balance water pipe. This device can directly and effectively adjust the pressure difference between the front and rear sides of the balance disc in a short time, making the balancing force generated by the balance disc tend to balance the axial thrust, reducing the stress on the thrust bearing, and thus reducing the rapid temperature rise of the thrust bearing due to friction.

Description

Technical Field

[0001] This invention belongs to the field of steam-driven feedwater pump technology, specifically a temperature control system for the thrust bearing of a steam-driven feedwater pump. Background Technology

[0002] In the production process of thermal power plants, steam-driven feedwater pumps play a crucial role in boiler water supply. Under the action of high-speed impeller rotation, deoxygenated feedwater with a certain temperature is continuously drawn into the pump body. Under the thrust generated by the impeller, the drawn feedwater is pushed to the rear of the impeller, and the pressurized feedwater is delivered to the boiler. During the pressurization process, the impeller generates an axial thrust in the direction of the impeller's suction side due to the pressure difference between the suction and discharge sides. Therefore, the balance of axial thrust plays an important role in the safe and reliable operation of the feedwater pump.

[0003] In existing technologies, the methods for balancing the axial thrust of an impeller are mostly to use a balancing device consisting of a balancing disc and a balancing plate, which works in conjunction with a thrust bearing. When the impeller rotates at high speed, the pressurized feed water forms unequal pressures on the front and rear sides of the balancing disc. As a result, the balancing disc generates a balancing force opposite to the axial thrust under the action of the pressure difference. At the same time, the balancing disc and the thrust bearing work together to bear this axial thrust in order to balance the axial thrust of the impeller.

[0004] However, when the balancing force generated by the balancing device is insufficient to counteract the axial thrust of the water pump, the balancing disc moves to the position where it contacts the balancing plate and causes friction. This leads to wear on the relative surfaces of the balancing plate and the balancing disc, increasing the axial gap between them. Consequently, the original balance point of the pump body shifts, increasing the stress on the non-working surface of the thrust bearing and increasing the friction of the thrust bearing. This results in the thrust bearing of the water pump being too hot or even burning out.

[0005] To address this, a temperature control system for the thrust bearing of a steam-driven feedwater pump is proposed. Summary of the Invention

[0006] The purpose of this invention is to provide a temperature control system for the thrust bearing of a steam-driven feedwater pump, which adjusts the flow rate of the feedwater return in the balance water pipe by adjusting the flow rate of the balance water pipe to regulate the pressure difference before and after the balance disc, thereby balancing the balance force and the axial thrust, reducing the stress on the non-working surface of the thrust bearing, and achieving the purpose of reducing the temperature of the thrust bearing.

[0007] To achieve the above objectives, the present invention provides the following technical solution:

[0008] A temperature control system for the thrust bearing of a steam-driven feedwater pump includes a pump body. The pump body is provided with an inlet pipe, an outlet pipe, and a balance water pipe. Both ends of the balance water pipe are connected to a cavity inside the pump body and are connected in parallel to the outside of the pump body to ensure that the feedwater in the pump body cavity flows smoothly back into the inlet pipe. A flow regulating device is installed on the surface of the balance water pipe to control the flow rate and pressure of the return feedwater in the balance water pipe. The flow regulating device includes:

[0009] The valve body has an internal chamber;

[0010] The flow channel runs through both sides of the valve body and communicates with the chamber of the valve body.

[0011] An adjusting rod is connected to the inside of the valve body and rotatably connected to the part that fits against the valve body. The surface of the adjusting rod inside the valve body cavity is threaded.

[0012] A flow control plate is slidably connected to the inner walls on both sides of the valve body chamber. The flow control plate forms a shield relative to the flow channel. The flow control plate is threadedly connected to the adjusting rod through a threaded groove to adjust the flow rate of water supplied in the flow channel.

[0013] Flow control plates are arranged alternately on the inner wall of the flow channel to prolong the flow path of the water in the flow channel, thereby reducing the flow velocity and pressure of the water.

[0014] The lower end of the flow control plate is bent towards the water inlet pipe, and the surface of the flow control plate is curved. The curved surface of the flow control plate is opposite to the curved surface of the flow control plate adjacent to the inlet side of the flow channel. The flow control plate can gently guide the water flow into the flow path formed by the flow control plate, and at the same time, the flow control plate further extends the flow path formed by the flow control plate.

[0015] There are many possible path structures for the flow channel, such as a straight, S-shaped, or L-shaped cross-section. In this invention, the flow channel forms a path for water to flow in a meandering manner through staggered flow control plates. When the returning feed water flows into the flow channel, it will flow along the serpentine path formed by the flow control plates under their action, thereby extending the flow path of the feed water, reducing the pressure of the feed water when it finally flows back into the inlet pipe, and reducing the damage of the feed water to the inner wall of the inlet pipe.

[0016] The flow regulating device is arranged in a cross shape inside the balance water pipe. The flow regulating device is located at one end of the balance water pipe near the outlet pipe, and the water supply flow in the balance water pipe can be adjusted in a short time.

[0017] There are many options for installing the flow regulating device on the balancing water pipe. It can be installed at any position on the balancing water pipe, namely the front, middle, and rear ends. In this invention, the flow regulating device is installed on a section of the balancing water pipe near the outlet pipe, similar to the rear end. This position is relatively close to the balancing chamber on the inner wall of the pump body. When the water pump vibrates, i.e., the position of the balancing point shifts and the thrust bearing heats up due to friction, the flow regulating device, being close to the balancing chamber, controls the flow regulating device to rotate the regulating rod. Through the screw drive, the flow control plate moves upward inside the valve body, reducing the obstruction of the flow channel by the flow control plate and increasing the gap between the flow control plate and the flow channel that allows water to flow. In a short time, more water can flow from the balancing chamber into the balancing water pipe, thereby quickly and effectively adjusting the flow rate of the liquid in the balancing water pipe in the shortest possible time, thus regulating the pressure difference before and after the balancing disc.

[0018] Preferably, the flow control plate has a C-shaped cross-section, and both ends of the flow control plate block the water supply in the flow channel. After the flow control plate descends, the water supply will generate a water hammer effect due to inertia, which will cause resistance to the surface of the flow control plate.

[0019] The flow control plate in this invention uses a C-shaped cross-section. Compared with the current single-rod structure, this structure can distribute the water hammer effect caused by the inertia of the water flow by the lower end walls on both sides of the flow control plate when the valve body rapidly reduces the water flow or shuts off the pump. Compared with the single-rod structure to bear the impact force of the water hammer effect, the C-shaped flow control plate can distribute the impact force of the water hammer effect evenly.

[0020] Preferably, the lower end of the flow control plate is rotatably connected to the balance water pipe via a torsion spring, and a limit groove is provided on the inner wall of the balance water pipe. The flow control plate, in conjunction with the torsion spring, can adjust the tilt angle according to the water flow rate to avoid excessive resistance of the flow control plate to the water supply.

[0021] Preferably, the elastic coefficient of the torsion spring decreases gradually along the water return direction, and at the same time, the rotatable angle area of ​​the limiting groove also decreases gradually along the water return direction.

[0022] The beneficial effects of this invention are as follows:

[0023] 1. The present invention provides a temperature control system for the thrust bearing of a steam-driven feedwater pump. By using a flow regulating device installed on the side of the balance water pipe connected in parallel with the pump body near the outlet pipe, the pressure difference between the front and rear sides of the balance disc can be directly and effectively adjusted in a short time. This makes the balance force generated by the balance disc and the axial thrust tend to be balanced, reducing the stress on the non-working surface of the thrust bearing and reducing the temperature of the thrust bearing, thereby ensuring that the feedwater pump can operate stably for a long time.

[0024] 2. The present invention provides a temperature control system for the thrust bearing of a steam-driven feedwater pump. By installing flow control plates and flow control plates with a certain curvature in the flow channel, it avoids damage to the flow regulation device when the high-pressure feedwater flows back, and also avoids the high-pressure accumulated water from violently impacting the pipe wall of the inlet pipe during the process of flowing back to the inlet pipe. This reduces the wear caused by the backflow feedwater on the inner wall of the inlet pipe, and also slows down the speed of liquid flowing back into the inlet pipe, thereby reducing the vibration of the pump body caused by the impact water flow.

[0025] 3. The present invention provides a temperature control system for the thrust bearing of a steam-driven feedwater pump. The lower end of the system is connected to the balance water pipe via a torsion spring. During the process of supplying a large flow of feedwater, the flow control plate will rotate automatically according to the size of the water flow to change the resistance of the flow control plate to the flowing feedwater. At the same time, the rotation angle of the flow control plate will gradually decrease along the direction of feedwater flow. Therefore, while slowing down the flow speed of the feedwater, it can also automatically adjust the interception resistance according to the flow rate and speed of the water flow, thereby reducing the impact force of the feedwater on the valve body. Attached Figure Description

[0026] The invention will now be further described with reference to the accompanying drawings.

[0027] Figure 1 This is a main body diagram of the present invention;

[0028] Figure 2 This is a top view of the present invention;

[0029] Figure 3 This is the present invention. Figure 2 A partial sectional view;

[0030] Figure 4 This is a schematic diagram of the flow control plate of the present invention;

[0031] In the diagram: 1. Pump body; 2. Inlet pipe; 3. Outlet pipe; 4. Balance water pipe; 41. Limiting groove; 5. Valve body; 6. Flow channel; 7. Adjusting rod; 8. Flow control plate; 9. Flow control disc; 91. Torsion spring. Detailed Implementation

[0032] To make the technical means, creative features, objectives and effects of this invention easier to understand, the invention will be further described below in conjunction with specific embodiments.

[0033] This invention provides a temperature control system for the thrust bearing of a steam-driven feedwater pump, comprising a pump body 1. The pump body 1 is provided with an inlet pipe 2, an outlet pipe 3, and a balance water pipe 4. The two ends of the balance water pipe 4 are connected to the internal cavity of the pump body 1 and are connected in parallel to the outside of the pump body 1 to ensure that the feedwater in the cavity of the pump body 1 flows smoothly back into the inlet pipe 2. The system is characterized in that: a flow regulating device is installed on the surface of the balance water pipe 4 to control the flow rate and pressure of the feedwater flowing back into the balance water pipe 4. The flow regulating device includes:

[0034] Valve body 5 has an internal chamber;

[0035] The flow channel 6 runs through both sides of the valve body 5 and communicates with the chamber of the valve body 5;

[0036] Adjusting rod 7 is connected to the interior of valve body 5 and rotatably connected to the part that fits against valve body 5. The surface of the part of adjusting rod 7 that is inside the cavity of valve body 5 is threaded.

[0037] The flow control plate 8 is slidably connected to the inner walls on both sides of the chamber of the valve body 5. The flow control plate 8 forms a shield relative to the flow channel 6. The flow control plate 8 is threadedly connected to the adjusting rod 7 through a threaded groove to adjust the flow rate of water supplied in the flow channel 6.

[0038] The flow control plates 9 are arranged alternately on the inner wall of the flow channel 6 to extend the flow path of the water in the flow channel 6 and reduce the flow velocity and pressure of the water.

[0039] The lower end of the flow control plate 8 is bent towards the water inlet pipe 2. The surface of the flow control plate 9 is arc-shaped. The curved surface of the flow control plate 8 is opposite to the arc-shaped surface of the flow control plate 9 adjacent to the inlet side of the flow channel 6. The flow control plate 8 can gently guide the water flow into the flow path formed by the flow control plate 9. At the same time, the flow control plate 8 further extends the flow path formed by the flow control plate 9.

[0040] In the prior art, the pump body 1 works by using a high-speed rotating impeller to pressurize the feed water entering from the inlet pipe 2. As a result, the feed water flowing out from the impeller at the end has a certain pressure P. This part of the feed water flows into the balance chamber through the gap between the balance plate and the balance disc, making the balance chamber a high-pressure state. Since the balance chamber is connected to the inlet pipe 2 through the balance water pipe 4, the pressure in the balance chamber is approximately the same as the pressure of the feed water in the inlet pipe 2, i.e., P1. The liquid pressure entering the gap will drop from P to P2. Due to the difference between P1 and P2, a pressure difference is formed between the front and rear sides of the balance disc. The value of P2 is greater than P1, which causes the balance disc to move backward under the push of the liquid pressure, increasing the gap between the balance disc and the balance plate. In this way, the force pushing the balance disc is used as a balancing force to form a force in the opposite direction to the axial thrust of the impeller, so as to keep the impeller in a balanced state.

[0041] Therefore, under the combined action of radial and axial clearances between the balance disc and the balance plate, the balance disc changes the balancing force by generating a pressure difference through leakage. Without leakage, the axial force cannot be completely balanced. However, as the balance disc and the balance plate are used for a long time, friction inevitably occurs, causing wear on their relative surfaces. This increases the axial and radial clearances between them, resulting in a decrease in the dynamic balancing function of the balance disc and seriously affecting the service life of the thrust bearing. Therefore, this invention adjusts the liquid flow rate in the balance water pipe 4 by installing a flow regulating device on the balance water pipe 4 that connects the balance chamber of the water pump and the inlet pipe 2.

[0042] When the steam-driven feedwater pump is running at high speed, the operator rotates the adjusting rod 7 to rotate it inside the valve body 5. Through the helical transmission between the thread and the thread groove, the flow control plate 8 is moved upward, adjusting the gap between the flow channel 6 and the flow control plate 8. This increases the feedwater flow rate that can flow into the flow channel 6 at the same time, allowing more feedwater to flow from the balance chamber into the balance water pipe 4 in a short time. This quickly and effectively adjusts the flow rate of the liquid in the balance water pipe 4, thereby regulating the pressure difference before and after the balance disc. This makes the balance force generated by the balance disc and the axial thrust tend to be balanced, preventing the thrust bearing from overheating due to friction.

[0043] When the flowing water contacts the flow control plate 8 before the flow channel, the arc-shaped surface at the lower end of the flow control plate 8, which is in the same direction as the water flow, can reduce the resistance generated when the returning water contacts the flow control plate 8, so that the water can flow into the flow channel 6 more smoothly. At the same time, the staggered flow control plates 9 form a meandering path for the water supply in the flow channel 6. When the water flows into the flow channel 6, it will flow along the serpentine path formed by the staggered flow control plates 9 under the guidance of the flow control plates 9, extending the flow path of the water supply in the valve body 5. Meanwhile, the flow control plates 9 with arc surfaces can make the liquid that just comes into contact smoothly enter the flow channel 6 along the arc surface, reducing the liquid pressure that just enters the balance water pipe 4. This avoids damage to the flow regulation device caused by strong water pressure, and also avoids the high-pressure liquid from violently hitting the pipe wall of the inlet pipe 2 during the return flow to the inlet pipe 2.

[0044] During the entire reflux process, the foremost flow control plate 8 is located at the lower end of the balance water pipe 4, arranged in an alternating vertical manner with the front flow control plate 8, and their curvatures face each other. Therefore, the flow control plate 8 can cooperate with the flow control plate 9, allowing the liquid entering the flow channel 6 to slow down its instantaneous pressure and velocity along the lower curved surface of the flow control plate 8, reducing the impact of the liquid on the overall flow regulation device and minimizing damage to the equipment. Simultaneously, guided by the flow control plate 8, the liquid flows downwards along the curved surface before contacting the first flow control plate 9. Then, the liquid flows upward along the curved surface. The flow control plate 9, together with the flow control plate 8, extends the meandering path. At the same time, the two work together to allow the liquid to enter the serpentine meandering path earlier, reducing the pressure and speed of the liquid flow. This prevents the high-pressure liquid from rapidly entering the flow channel 6 and impacting the valve body 5, causing damage. It also further reduces the pressure of the liquid flowing back into the inlet pipe 2, preventing the liquid from damaging the pipe wall of the inlet pipe 2. Thus, while ensuring the stable operation of the pump body 1, that is, the thrust bearing will not overheat and the pump body 1 will not vibrate, it can also reduce the damage caused by the high-pressure water flow during the return process.

[0045] In one specific embodiment of the present invention, the flow regulating device is arranged in a cross shape with the balance water pipe 4. The flow regulating device is located at one end of the balance water pipe 4 near the outlet pipe 3, and the water supply flow rate in the balance water pipe 4 can be adjusted in a short time.

[0046] The flow regulating device, which is arranged in a cross shape with the balance water pipe 4, can directly control the flow rate of the water supplied in the balance water pipe 4. When the water pump vibrates, that is, when the position of the balance point shifts and the thrust bearing heats up due to friction, the flow regulating device, which is close to the balance chamber, rotates the regulating rod 7. Through the screw drive, the flow control plate 8 moves upward inside the valve body 5, reducing the obstruction of the flow channel 6 by the flow control plate 8 and increasing the gap between the flow control plate 8 and the flow channel 6 that allows water to flow. In a short time, more water can flow from the balance chamber into the balance water pipe 4, thereby quickly and effectively adjusting the flow rate of the liquid in the balance water pipe 4 in the shortest time, and thus adjusting the pressure difference before and after the balance plate.

[0047] In one specific embodiment of the present invention, the flow control plate 8 has a C-shaped cross section. Both ends of the flow control plate 8 block the water supply in the flow channel 6. The water supply, due to inertia, generates a water hammer effect after the flow control plate 8 descends, which causes resistance to the surface of the flow control plate 8.

[0048] During the operation of the pump body 1, the water pressure at the end of the impeller changes due to the different speed of each impeller rotation. This causes the pressure difference between the front and rear sides of the balance plate to change, requiring the operator to quickly adjust the flow rate in the balance water pipe 4 to balance the balancing force and axial thrust. When it is necessary to reduce the water flow rate in the balance water pipe 4, the flow control plate 8 is moved downward. After the diameter of the flow channel 6 is reduced, the originally large flow of water will form a water hammer effect on the lower surface of the flow control plate 8 due to its own inertia, causing certain damage to the valve body 5 as a whole.

[0049] Furthermore, this application utilizes the lower end walls of the front and rear sides of the C-shaped flow control plate 8 to bear the water hammer effect caused by the inertia of the feed water, thus evenly dispersing the impact force generated by the water hammer effect. Simultaneously, the lower end wall of the front flow control plate 8 guides the feed water to flow along the arc-shaped surface, reducing the resistance between the flowing feed water and the flow control plate 8, allowing the feed water to still flow smoothly into the flow channel 6. Moreover, the staggered flow control plates 9 within the flow channel 6 reduce the flow velocity of the feed water, slowing down the final flow velocity of the feed water exiting the flow channel 6. Furthermore, when the rear flow control plate 8 resists… After the water flow is blocked, the blocked water will flow back into the flow channel 6. Due to the presence of the flow control plate 9, the backflowing water is further reduced by the flow control plate 9, thus reducing the impact force generated by the water hammer effect. This makes the water hammer effect weakened to the greatest extent between the flow control plate 8 and the flow control plate 9. In this invention, the arc-shaped end walls on the front and rear sides of the flow control plate 8, together with the flow control plate 9 in the flow channel 6, gradually reduce the impact force generated by the water hammer effect, greatly reducing the damage to the valve body 5 caused by the water hammer effect formed by the water supply when the flow rate is rapidly reduced and the pump body 1 is closed.

[0050] In one specific embodiment of the present invention, the lower end of the flow control plate 9 is rotatably connected to the balance water pipe 4 via a torsion spring 91, and a limiting groove 41 is provided on the inner wall of the balance water pipe 4. The flow control plate 9, in conjunction with the torsion spring 91, can adjust the tilt angle according to the size of the water supply flow rate, so as to avoid excessive resistance of the flow control plate 9 to the water supply. The elastic coefficient of the torsion spring 91 is gradually reduced along the water supply return direction. At the same time, the rotatable angle area of ​​the limiting groove 41 is also gradually reduced along the water supply return direction.

[0051] During the process of increasing the water flow rate in the flow channel 6, the sudden increase in water flow rate, although the flow control plate 9 has an arc-shaped surface to guide the water flow direction, will still increase the resistance between the water flow and the flow control plate 9, which may easily cause the flow regulation device to vibrate relative to the balance water pipe 4. Therefore, the flow control plate 9, which is rotatably connected to the balance water pipe 4 by the torsion spring 91, will rotate relative to the balance water pipe 4 under the action of the water flow impact force when the water flow suddenly increases, reducing the resistance between the flow control plate 9 and the water flow. Although the flow control plate 9 reduces the resistance between it and the water flow, it will still play the role of slowing down the water flow velocity. At the same time, as the water flow passes through each flow control plate 9, its own flow velocity will be slowed down. And the further along the water flow direction, the smaller the angle that the flow control plate 9 can rotate under the restriction of the limiting groove 41 becomes, thereby slowing down the water flow velocity to the greatest extent and reducing the impact force of the water flowing back into the water inlet pipe 2 on the pipe wall.

[0052] Moreover, when the pump body 1 is shut off or the water flow rate is reduced, the water will flow back after passing through the flow channel 6 due to inertia and being obstructed by the rear wall of the flow control plate 8. At this time, the flow control plate 9 will be reset under the elasticity of the torsion spring 91 and the push of the backflowing water, so that the flow velocity of the backflowing water will gradually decrease along the reset flow control plate 9, which will further reduce the impact of water hammer effect.

[0053] Working principle: In the existing technology, the pump body 1 works by using a high-speed rotating impeller to pressurize the feed water entering from the inlet pipe 2. As a result, the feed water flowing out from the impeller at the end has a certain pressure P. This part of the feed water flows into the balance chamber through the gap between the balance plate and the balance disc, making the balance chamber a high-pressure state. Since the balance chamber is connected to the inlet pipe 2 through the balance water pipe 4, the pressure in the balance chamber is approximately the same as the pressure of the feed water in the inlet pipe 2, i.e., P1. The liquid pressure entering the gap will drop from P to P2. Due to the difference between P1 and P2, a pressure difference is formed between the front and rear sides of the balance disc. The value of P2 is greater than P1, which causes the balance disc to move backward under the push of the liquid pressure, increasing the gap between the balance disc and the balance plate. In this way, the force pushing the balance disc is used as a balancing force to form a force in the opposite direction to the axial thrust of the impeller, so as to keep the impeller in a balanced state.

[0054] Therefore, under the combined action of radial and axial clearances between the balance disc and the balance plate, the balance disc changes the balancing force by generating a pressure difference through leakage. Without leakage, the axial force cannot be completely balanced. However, as the balance disc and the balance plate are used for a long time, friction inevitably occurs, causing wear on their relative surfaces. This increases the axial and radial clearances between them, resulting in a decrease in the dynamic balancing function of the balance disc and seriously affecting the service life of the thrust bearing. Therefore, this invention adjusts the liquid flow rate in the balance water pipe 4 by installing a flow regulating device on the balance water pipe 4 that connects the balance chamber of the water pump and the inlet pipe 2.

[0055] When the steam-driven feedwater pump is running at high speed, the operator rotates the adjusting rod 7 to rotate it inside the valve body 5. Through the helical transmission between the thread and the thread groove, the flow control plate 8 is moved upward, adjusting the gap between the flow channel 6 and the flow control plate 8. This increases the feedwater flow rate that can flow into the flow channel 6 at the same time, allowing more feedwater to flow from the balance chamber into the balance water pipe 4 in a short time. This quickly and effectively adjusts the flow rate of the liquid in the balance water pipe 4, thereby regulating the pressure difference before and after the balance disc. This makes the balance force generated by the balance disc and the axial thrust tend to be balanced, preventing the thrust bearing from overheating due to friction.

[0056] When the flowing water contacts the flow control plate 8 before the flow channel, the arc-shaped surface at the lower end of the flow control plate 8, which is in the same direction as the water flow, can reduce the resistance generated when the returning water contacts the flow control plate 8, so that the water can flow into the flow channel 6 more smoothly. At the same time, the staggered flow control plates 9 form a meandering path for the water supply in the flow channel 6. When the water flows into the flow channel 6, it will flow along the serpentine path formed by the staggered flow control plates 9 under the guidance of the flow control plates 9, extending the flow path of the water supply in the valve body 5. Meanwhile, the flow control plates 9 with arc surfaces can make the liquid that just comes into contact smoothly enter the flow channel 6 along the arc surface, reducing the liquid pressure that just enters the balance water pipe 4. This avoids damage to the flow regulation device caused by strong water pressure, and also avoids the high-pressure liquid from violently hitting the pipe wall of the inlet pipe 2 during the return flow to the inlet pipe 2.

[0057] During the entire reflux process, the foremost flow control plate 8 is located at the lower end of the balance water pipe 4, arranged in an alternating vertical manner with the front flow control plate 8, and their curvatures face each other. Therefore, the flow control plate 8 can cooperate with the flow control plate 9, allowing the liquid entering the flow channel 6 to slow down its instantaneous pressure and velocity along the lower curved surface of the flow control plate 8, reducing the impact of the liquid on the overall flow regulation device and minimizing damage to the equipment. Simultaneously, guided by the flow control plate 8, the liquid flows downwards along the curved surface before contacting the first flow control plate 9. Then, the liquid flows upward along the curved surface. The flow control plate 9, together with the flow control plate 8, extends the meandering path. At the same time, the two work together to allow the liquid to enter the serpentine meandering path earlier, reducing the pressure and speed of the liquid flow. This prevents the high-pressure liquid from rapidly entering the flow channel 6 and impacting the valve body 5, causing damage. It also further reduces the pressure of the liquid flowing back into the inlet pipe 2, preventing the liquid from damaging the pipe wall of the inlet pipe 2. Thus, while ensuring the stable operation of the pump body 1, that is, the thrust bearing will not overheat and the pump body 1 will not vibrate, it can also reduce the damage caused by the high-pressure water flow back.

[0058] During the operation of the pump body 1, the water pressure at the end of the impeller changes due to the different speed of each impeller rotation. This causes the pressure difference between the front and rear sides of the balance plate to change, requiring the operator to quickly adjust the flow rate in the balance water pipe 4 to balance the balancing force and axial thrust. When it is necessary to reduce the water flow rate in the balance water pipe 4, the flow control plate 8 is moved downward. After the diameter of the flow channel 6 is reduced, the originally large flow of water will form a water hammer effect on the lower surface of the flow control plate 8 due to its own inertia, causing certain damage to the valve body 5 as a whole.

[0059] Furthermore, this application utilizes the lower end walls of the front and rear sides of the C-shaped flow control plate 8 to bear the water hammer effect caused by the inertia of the feed water, thus evenly dispersing the impact force generated by the water hammer effect. Simultaneously, the lower end wall of the front flow control plate 8 guides the feed water to flow along the arc-shaped surface, reducing the resistance between the flowing feed water and the flow control plate 8, allowing the feed water to still flow smoothly into the flow channel 6. Moreover, the staggered flow control plates 9 within the flow channel 6 reduce the flow velocity of the feed water, slowing down the final flow velocity of the feed water exiting the flow channel 6. Furthermore, when the rear flow control plate 8 resists… After the water flow is blocked, the blocked water will flow back into the flow channel 6. Due to the presence of the flow control plate 9, the backflowing water is further reduced by the flow control plate 9, thus reducing the impact force generated by the water hammer effect. This makes the water hammer effect weakened to the greatest extent between the flow control plate 8 and the flow control plate 9. In this invention, the arc-shaped end walls on the front and rear sides of the flow control plate 8, together with the flow control plate 9 in the flow channel 6, gradually reduce the impact force generated by the water hammer effect, greatly reducing the damage to the valve body 5 caused by the water hammer effect formed by the water supply when the flow rate is rapidly reduced and the pump body 1 is closed.

[0060] During the process of increasing the water flow rate in the flow channel 6, the sudden increase in water flow rate, although the flow control plate 9 has an arc-shaped surface to guide the water flow direction, will still increase the resistance between the water flow and the flow control plate 9, which may easily cause the flow regulation device to vibrate relative to the balance water pipe 4. Therefore, the flow control plate 9, which is rotatably connected to the balance water pipe 4 by the torsion spring 91, will rotate relative to the balance water pipe 4 under the action of the water flow impact force when the water flow suddenly increases, reducing the resistance between the flow control plate 9 and the water flow. Although the flow control plate 9 reduces the resistance between it and the water flow, it will still play the role of slowing down the water flow velocity. At the same time, as the water flow passes through each flow control plate 9, its own flow velocity will be slowed down. And the further along the water flow direction, the smaller the angle that the flow control plate 9 can rotate under the restriction of the limiting groove 41 becomes, thereby slowing down the water flow velocity to the greatest extent and reducing the impact force of the water flowing back into the water inlet pipe 2 on the pipe wall.

[0061] Moreover, when the pump body 1 is shut off or the water flow rate is reduced, the water will flow back after passing through the flow channel 6 due to inertia and being obstructed by the rear wall of the flow control plate 8. At this time, the flow control plate 9 will be reset under the elasticity of the torsion spring 91 and the push of the backflowing water, so that the flow velocity of the backflowing water will gradually decrease along the reset flow control plate 9, which will further reduce the impact of water hammer effect.

[0062] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A temperature control system for the thrust bearing of a steam-driven feedwater pump, comprising a pump body (1), wherein the pump body (1) is provided with an inlet pipe (2), an outlet pipe (3), and a balance water pipe (4), wherein both ends of the balance water pipe (4) are connected to the cavity inside the pump body (1) and are connected in parallel to the outside of the pump body (1) to ensure that the feedwater in the cavity of the pump body (1) flows smoothly back into the inlet pipe (2), characterized in that: The balance water pipe (4) is equipped with a flow regulating device to control the flow rate and pressure of the return water in the balance water pipe (4). The flow regulating device includes: a valve body (5) with an internal chamber; a flow channel (6) that passes through both sides of the valve body (5) and communicates with the chamber of the valve body (5); an adjusting rod (7) that connects to the inside of the valve body (5) and is rotatably connected to the part of the valve body (5) that is in contact with it, and the adjusting rod (7) has a thread on its surface at the part of the valve body (5) that is inside the chamber; and a flow control plate (8) that is slidably connected to the inner walls on both sides of the chamber of the valve body (5), and the flow control plate (8) forms a shield relative to the flow channel (6), and the flow control plate (8) is connected to the adjusting rod through a threaded groove. (7) Threaded drive connection, used to adjust the flow rate of water in the flow channel (6); flow control plates (9) are staggered on the inner wall of the flow channel (6) to extend the flow path of water in the flow channel (6) and reduce the flow speed and pressure of water; the lower end of the flow control plate (8) is bent towards the water inlet pipe (2), the surface of the flow control plate (9) is arc-shaped, the curved surface of the flow control plate (8) is opposite to the arc-shaped surface of the flow control plate (9) adjacent to the inlet side of the flow channel (6), the flow control plate (8) can gently guide the water flow into the flow path formed by the flow control plate (9), and at the same time the flow control plate (8) further extends the flow path formed by the flow control plate (9); The flow regulating device is arranged in a cross shape inside the balance water pipe (4). The flow regulating device is located at one end of the balance water pipe (4) near the outlet pipe (3), and the water supply flow rate in the balance water pipe (4) can be adjusted in a short time. The flow control plate (8) has a C-shaped cross section. Both ends of the flow control plate (8) block the water supply in the flow channel (6). The water supply generates a water hammer effect due to inertia after the flow control plate (8) descends, which causes resistance to the surface of the flow control plate (8). The lower end of the flow control plate (9) is rotatably connected to the balance water pipe (4) via a torsion spring (91), and the balance water pipe (4) has a limit groove (41) on its inner wall. The flow control plate (9) and the torsion spring can adjust the tilt angle according to the size of the water flow rate to avoid excessive resistance of the flow control plate (9) to the water supply. The elastic coefficient of the torsion spring (91) decreases gradually along the water return direction, and at the same time, the rotatable angle area of ​​the limiting groove (41) also decreases gradually along the water return direction.

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