Control device for stabilizing pressure

Abstract

The utility model discloses a stable pressure control device which comprises a process condensing box, an iron removal filter, a front cation bed and a pneumatic butterfly valve which are connected through a conveying pipeline, three sets of process condensing pumps are arranged between the process condensing box and the iron removal filter in parallel, and stop valves are arranged on outlet pipelines of the process condensing pumps. Condensate in the process condensation boxes is conveyed to the front cation bed through the process condensation pumps, the pneumatic butterfly valves are arranged on inlet pipelines of the front cation bed, pressure stabilizing devices are arranged on the process condensation pumps, outlet pressure of all the process condensation pumps is controlled through the pressure stabilizing devices, and water pressure in the inlet pipelines and the outlet pipelines of the front cation bed is kept stable through the pressure stabilizing devices. Therefore, when the pneumatic butterfly valve is closed, valve / pipeline vibration caused by the water hammer effect is reduced. The problem that a pneumatic butterfly valve has a water hammer effect due to unstable internal water pressure of a desalted water project can be solved, the structure is simple, control is convenient, and the internal water pressure of a pipeline is adjusted stably.

Description

Technical Field

[0001] This utility model relates to the technical field of energy-saving equipment, specifically to a pressure stabilization control device. Background Technology

[0002] Currently, in the demineralized water project, the condensate in the process condenser is transported to an iron removal filter by multiple parallel process condensate pumps before entering the pre-cation bed for use. The process condensate pumps are fixed-frequency pumps, and the condensate delivery rate is switched by activating different numbers of process condensate pumps and valves. When controlling the condensate flow rate, manual intervention is required to activate a backup pump to compensate for decreases or increases in pipeline pressure. For example, if the power delivered by one process condensate pump is insufficient to meet the pipeline pressure requirements, another process condensate pump is manually started, and the flow rate is adjusted by changing the valve opening until all three pumps are running at full capacity and the valves are fully open, reaching the maximum flow rate. While the brine project can control the liquid pressure within the pipeline, unstable pressure within the cation bed delivery pipeline can easily occur during switching.

[0003] In the demineralized water project, the shut-off valve at the feed end of the cation exchange bed is a pneumatic butterfly valve. During use, the valve at the process condensate pump closes too quickly, which can easily create a water hammer effect. The water flow impacts the valve plate, causing the section of the valve stem between the valve plate and the valve seat to be subjected to shear stress when the valve is closed. This causes elastic deformation or even plastic deformation of the valve stem, resulting in damage to the valve lining and bending of the valve stem. Summary of the Invention

[0004] In order to solve one or more technical problems existing in the prior art, the purpose of this application is to provide a pressure stabilization control device that can solve the problem of water hammer effect in pneumatic butterfly valves caused by unstable internal water pressure in desalination projects. The device has a simple structure, is easy to control, and provides stable internal water pressure regulation in the pipeline.

[0005] To solve the aforementioned technical problems, this application adopts the following technical solution:

[0006] A pressure stabilization control device includes a process condenser, an iron removal filter, a pre-cation bed, and a pneumatic butterfly valve connected by a delivery pipeline. Three sets of process condensation pumps are connected in parallel between the process condenser and the iron removal filter. A shut-off valve is installed on the outlet pipeline of each process condensation pump. The condensate in the process condenser is delivered to the pre-cation bed through the process condensation pumps. The pneumatic butterfly valve is installed on the inlet pipeline of the pre-cation bed. A pressure stabilizing device is installed on each process condensation pump. The outlet pressure of each process condensation pump is controlled by the pressure stabilizing device. The water pressure in the inlet and outlet pipelines of the pre-cation bed is kept stable by the pressure stabilizing device, thereby reducing valve / pipeline vibration caused by water hammer effect when the pneumatic butterfly valve closes.

[0007] Preferably, the pressure stabilizing device includes a pressure gauge installed on the inlet pipe of the pre-cation bed, and a DCS controller connected to the three sets of process condensate pumps via electrical signal lines. The DCS controller is linked to the pressure gauge for control. The process condensate pumps are variable frequency delivery pumps. The output power of each process condensate pump is controlled by the DCS controller to stabilize the pressure detected in the pressure gauge. The pneumatic butterfly valve reduces the water hammer effect after stabilizing the pressure through the liquid inlet of the pre-cation bed.

[0008] Preferably, the pneumatic butterfly valve includes a valve body enclosed in a pipeline and a pneumatic actuator for controlling the opening and closing of the valve body. A pressure reducing component is provided on the air supply line of the pneumatic actuator, and the valve closing speed of the pneumatic actuator on the valve body is reduced by the pressure reducing component.

[0009] Preferably, the pneumatic actuator includes a filter pressure reducing valve connected to the instrument air pipeline, a solenoid valve connected to the filter pressure reducing valve through a pipeline, and a control cylinder connected to the solenoid valve. An air inlet pipe and an air outlet pipe are provided between the solenoid valve and the control cylinder, and the pressure reducing component is provided on the air outlet pipe.

[0010] Preferably, the pressure reducing component is a throttle valve.

[0011] Preferably, the inlet pipe end of the process condensate pump is equipped with a manual valve, and the two ends of the process condensate pump are detachably connected through the manual valve and the shut-off valve.

[0012] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0013] A pressure stabilizing device is added to the condensate supply pipeline of the cation bed in the demineralized water process. The pressure stabilizing device regulates the water pressure in the inlet and outlet pipelines of the pre-cation bed, thereby maintaining a stable increase or decrease in internal water pressure and avoiding acute pressure changes. This reduces valve / pipeline vibration caused by water hammer when the pneumatic butterfly valve closes.

[0014] By adding a pressure-reducing component to the pneumatic actuator of the pneumatic butterfly valve, combined with the addition of a pressure-stabilizing device, the water hammer effect at the pneumatic butterfly valve can be effectively eliminated, preventing pipeline vibration and valve damage caused by water hammer. This effectively solves the problem of water hammer effect in pneumatic butterfly valves caused by unstable internal water pressure in demineralized water projects. The structure is simple, control is convenient, and the internal water pressure regulation in the pipeline is stable. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of the overall structure of this utility model;

[0016] Figure 2 This is a schematic diagram of the control principle of the pneumatic butterfly valve in this utility model;

[0017] In the diagram: 1. Shut-off valve; 2. Process condensate pump; 3. Manual valve; 4. Pressure stabilizing device; 5. DCS controller; 6. Process condenser; 7. Iron removal filter; 8. Pressure gauge; 9. Pneumatic butterfly valve; 10. Pre-caking bed; 11. Inlet pipe; 12. Filter pressure reducing valve; 13. Solenoid valve; 14. Pressure reducing assembly; 15. Exhaust pipe; 16. Control cylinder; 17. Pneumatic actuator; 18. Valve body. Detailed Implementation

[0018] The present application will now be further described in conjunction with the accompanying drawings and specific embodiments. It should be noted that, without conflict, the various embodiments or technical features described below can be arbitrarily combined to form new embodiments.

[0019] In the description of this application, it should be understood that the terms "upper", "lower", "left", "right", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0020] The terms "first," "second," etc., used in this application are used to distinguish similar objects and not to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that embodiments of this application can be implemented in orders other than those illustrated or described herein, and the objects distinguished by "first," "second," etc., are generally of the same class, without limiting the number of objects; for example, a first object can be one or more. Furthermore, in the specification and claims, "and / or" indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0021] like Figure 1 and Figure 2 As shown, a pressure stabilization control device includes a process condenser 6, an iron removal filter 7, a pre-cation bed 10, and a pneumatic butterfly valve 9 connected by a conveying pipeline. Three sets of process condensation pumps 2 are connected in parallel between the process condenser 6 and the iron removal filter 7. A shut-off valve 1 is provided on the outlet pipeline of each process condensation pump 2. The condensate in the process condenser 6 is conveyed to the pre-cation bed 10 through the process condensation pumps 2. The pneumatic butterfly valve 9 is located on the inlet pipeline of the pre-cation bed 10. A pressure stabilizing device 4 is provided on each process condensation pump 2. The outlet pressure of each process condensation pump 2 is controlled by the pressure stabilizing device 4. The water pressure in the inlet and outlet pipelines of the pre-cation bed 10 is kept stable by the pressure stabilizing device 4, thereby reducing valve / pipeline vibration caused by water hammer effect when the pneumatic butterfly valve 9 is closed.

[0022] A pressure stabilizing device 4 is added to the condensate supply pipeline of the cation bed in the demineralization process. The pressure stabilizing device 4 regulates the water pressure in the inlet and outlet pipelines of the pre-cation bed 10, thereby maintaining a stable increase or decrease in internal water pressure and avoiding acute pressure changes. This reduces the vibration of the valve / pipeline caused by water hammer when the pneumatic butterfly valve 9 closes, effectively solving the problem of water hammer effect in the pneumatic butterfly valve 9 caused by unstable internal water pressure in the demineralization project. The structure is simple, the control is convenient, and the internal water pressure regulation of the pipeline is stable.

[0023] A further improvement is that the pressure stabilizing device 4 includes a pressure gauge 8 installed on the inlet pipe of the pre-anode bed 10, and a DCS controller 5 connected to the three sets of process condensate pumps 2 via electrical signal lines. The DCS controller 5 is linked with the pressure gauge 8 for control. The process condensate pumps 2 are variable frequency delivery pumps. The output power of each process condensate pump 2 is controlled by the DCS controller 5 to stabilize the pressure detected in the pressure gauge 8. The pneumatic butterfly valve 9 reduces the water hammer effect after the liquid inlet pressure is stabilized by the pre-anode bed 10.

[0024] In specific control, the process condensate pump 2 is set with an outlet pressure of P1 ± ΔP and an initial frequency of ν = 40Hz. The pressure and frequency adjustment Δν are also set, where P1, ΔP, ν, and Δν are all adjustable. ② If the pressure is lower than P1 - ΔP, one pump is started, and the frequency is increased / decreased starting from 40Hz. After the first pump reaches a frequency of 50Hz, if the outlet pressure is < P1 - ΔP, or the current of the first pump is > the rated current I1 (165.2A for the process condensate pump) for 15 seconds, the second pump (40Hz) is started, and the frequency is increased / decreased. ③ After the second pump starts, if the outlet pressure is > P1 + ΔP, the frequency is decreased. The pump is stopped after the frequency drops to 5Hz. This achieves stable pressure control.

[0025] A further improvement is that the pneumatic butterfly valve 9 is enclosed in a valve body 18 within a pipeline, and a pneumatic actuator 17 is provided on the air supply line of the pneumatic actuator 17 to control the opening and closing of the valve body 18. The valve closing speed of the pneumatic actuator 17 on the valve body 18 is reduced by the pressure reducing component 14.

[0026] Because the existing pneumatic actuator 17 is too fast when closing the valve body 18, it is prone to water hammer effect. The water flow impacts the valve plate, causing the section of the valve stem between the valve plate and the valve seat to be subjected to shear stress when the valve is closed. This causes elastic deformation or even plastic deformation of the valve stem, resulting in damage to the valve lining and bending of the valve stem. Therefore, a pressure reducing component 14 is added to the air supply line of the pneumatic actuator 17. When the pneumatic actuator 17 closes the valve body 18, the airflow speed is reduced by the pressure reducing component 14, thereby reducing the closing efficiency of the valve body 18 and ultimately reducing the damage to the valve body lining caused by the water hammer effect.

[0027] By adding a pressure reducing component 14 to the pneumatic actuator 17 of the pneumatic butterfly valve 9, and combining it with the addition of a pressure stabilizing device 4, the water hammer effect at the pneumatic butterfly valve 9 can be effectively eliminated, thus avoiding pipeline vibration and valve damage caused by the water hammer effect.

[0028] A further improvement is made to the pneumatic actuator 17, which includes a filter pressure reducing valve 12 connected to the instrument air network, a solenoid valve 13 connected to the filter pressure reducing valve 12 via a pipeline, and a control cylinder 16 connected to the solenoid valve 13. An air inlet pipe 11 and an exhaust pipe 15 are provided between the solenoid valve 13 and the control cylinder 16, and the pressure reducing assembly 14 is provided on the exhaust pipe 15.

[0029] Since the existing pneumatic actuator 17 connects the instrument air network, filter pressure reducing valve 12, solenoid valve 13 and control cylinder 16 in series through the air inlet pipe 11, and the air outlet of solenoid valve 13 and control cylinder 16 are connected in series through the exhaust pipe 15, after adding pressure reducing component 14 to the exhaust pipe 15, the valve body 18 closing efficiency can be more effectively reduced. By adding pressure reducing component 14, the exhaust pressure of solenoid valve 13 is reduced, thereby reducing the damage of water hammer effect to the valve body 18 liner. The structure is simple and the control is convenient.

[0030] The pressure-reducing component 14 is a throttle valve. When the pneumatic butterfly valve 9 is closed, the air inlet pipe 11 is closed and the air outlet pipe 15 is opened. The airflow in the actuator passes through the throttle valve, and the exhaust gas speed is slowed down, thereby controlling the valve closing speed. The valve closing time can be controlled by adjusting the throttle valve handwheel. When the valve is open, the air inlet is opened and the air outlet is closed. The airflow in the open airlet passes through the throttle valve and flows through the actuator. By adding a throttle valve, the exhaust pressure of the solenoid valve 13 is reduced, thereby reducing the damage of water hammer effect to the valve body 18 liner. The improved structure is simpler and the cost is lower. The closing speed of the pneumatic butterfly valve 9 can be controlled by adjusting the throttle valve handwheel, which can more accurately meet the equipment operation requirements and ensure the stable operation of the device.

[0031] A further improvement is that the inlet pipe end of the process condensate pump 2 is equipped with a manual valve 3, and the two ends of the process condensate pump 2 are detachably connected through the manual valve 3 and the shut-off valve 1.

[0032] Because the existing process condensate pump 2 is directly connected to the pipeline through a flange at the feed end, and a shut-off valve 1 is installed on the outlet pipe to control the flow rate and cut off the flow, but when the process condensate pump 2 is damaged, the main valve needs to be shut off before it can be replaced. Therefore, in order to facilitate the maintenance of the improved process condensate pump 2, a manual valve 3 is installed on the existing feed pipeline. During normal use, the manual valve 3 and the shut-off valve 1 are in the normally open state. When maintenance is required for a certain process condensate pump 2, it is only necessary to close the valves on both sides of the corresponding process condensate pump 2 to cut off the flow in both pipelines. This allows the process condensate pump 2 to be disassembled and replaced without stopping the machine. Maintenance is carried out using the shut-off valve 1 on the existing pipeline, which reduces the cost during the modification.

[0033] The above embodiments are merely preferred embodiments of this application and should not be construed as limiting the scope of protection of this application. Any non-substantial changes and substitutions made by those skilled in the art based on this application shall fall within the scope of protection claimed by this application.

Claims

1. A pressure stabilization control device, characterized in that: The system includes a process condenser (6), an iron removal filter (7), a pre-anode bed (10), and a pneumatic butterfly valve (9) connected by a conveying pipeline. Three sets of process condenser pumps (2) are connected in parallel between the process condenser (6) and the iron removal filter (7). A shut-off valve (1) is provided on the outlet pipeline of the process condenser pump (2). The condensate in the process condenser (6) is conveyed to the pre-anode bed (10) through the process condenser pump (2). The pneumatic butterfly valve (9) is located on the inlet pipeline of the pre-anode bed (10). A pressure stabilizing device (4) is provided on the process condenser pump (2). The outlet pressure of each process condenser pump (2) is controlled by the pressure stabilizing device (4). The water pressure in the inlet and outlet pipelines of the pre-anode bed (10) is kept stable by the pressure stabilizing device (4), thereby reducing the valve / pipeline vibration caused by water hammer when the pneumatic butterfly valve (9) is closed.

2. The pressure stabilization control device according to claim 1, characterized in that: The pressure stabilizing device (4) includes a pressure gauge (8) installed on the inlet pipe of the pre-anode bed (10) and a DCS controller (5) connected to the three sets of process condensation pumps (2) via electrical signal lines. The DCS controller (5) is linked with the pressure gauge (8) for control. The process condensation pumps (2) are variable frequency delivery pumps. The output power of each process condensation pump (2) is controlled by the DCS controller (5) to stabilize the pressure detected in the pressure gauge (8). The pneumatic butterfly valve (9) reduces the water hammer effect after the liquid inlet pressure is stabilized by the liquid inlet pressure stabilization of the pre-anode bed (10).

3. The pressure stabilization control device according to claim 2, characterized in that: The pneumatic butterfly valve (9) includes a valve body (18) disposed in a pipeline and a pneumatic actuator (17) for controlling the opening and closing of the valve body (18). A pressure reducing component (14) is provided on the air supply line of the pneumatic actuator (17), and the valve closing speed of the pneumatic actuator (17) on the valve body (18) is reduced by the pressure reducing component (14).

4. The pressure stabilization control device according to claim 3, characterized in that: The pneumatic actuator (17) includes a filter pressure reducing valve (12) connected to the instrument air network, a solenoid valve (13) connected to the filter pressure reducing valve (12) through a pipe, and a control cylinder (16) connected to the solenoid valve (13). An air inlet pipe (11) and an exhaust pipe (15) are provided between the solenoid valve (13) and the control cylinder (16). The pressure reducing assembly (14) is located on the exhaust pipe (15).

5. A pressure stabilization control device according to claim 3 or 4, characterized in that: The pressure reducing component (14) is a throttle valve.

6. The pressure stabilization control device according to claim 1, characterized in that: The process condensate pump (2) is equipped with a manual valve (3) at the water inlet pipe end, and the two ends of the process condensate pump (2) are detachably connected through the manual valve (3) and the shut-off valve (1).

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