An anti-surge device

Abstract

The present invention discloses an anti-surge device, which includes an instrument air source. The instrument air source is respectively connected to the intake ends of a filter pressure reducing valve a and a filter pressure reducing valve b through a ball valve. The filter pressure reducing valve a is respectively connected to a sleeve type pneumatic diaphragm regulating valve and a power-off quick-opening mechanism through a pneumatic relay. A Siemens valve positioner is installed on the sleeve type pneumatic diaphragm regulating valve, and a pressure detection mechanism is arranged on the Siemens valve positioner. The air supply end of the Siemens valve positioner is connected to the outlet end of the filter pressure reducing valve b. The Siemens valve positioner is connected to the intake end of a one-way throttle valve a, and the outlet end of the one-way throttle valve a is connected to the intake end of the power-off quick-opening mechanism. The present invention can solve the problems of uneven pressure on the internal diaphragm during the adjustment of the pneumatic diaphragm regulating valve, non-adjustable stroke time, and inability to self-hold when the solenoid valve fails and loses power.

Description

Technical Field

[0001] The present invention relates to the technical field of automated instrument measurement, and particularly relates to an anti-surge device. Background Art

[0002] To ensure the safe and stable operation of large rotating machinery systems, the instrument monitoring system is of great significance. The main detection instruments include shaft vibration, shaft displacement, bearing temperature, oil temperature, exhaust pressure, anti-surge control valves, etc. When their measured values reach the interlock value or the opening of the control valve is abnormal, the unit will shut down. When compressors such as large air compressors and oxygen-nitrogen compressors experience surging or the regulated parameters approach the surge line, the anti-surge valve needs to open quickly to reduce the output pressure and minimize the damage caused by surging to the unit. It is required that the quick-opening time of the anti-surge valve should be less than 2 seconds, and the full-closure time is usually adjusted to 8 - 10 seconds. Due to the large flow rate of the output medium of large rotating machinery, large pipe radius, and large pressure difference before and after the valve, the diaphragm head of the anti-surge control valve is usually designed larger than that of ordinary control valves to enhance the ability to overcome external resistance. However, this also increases the amount of gas entering the diaphragm head. The anti-surge control valve also exposes the following problems during actual regulation:

[0003] 1. When the unit is loaded, during the adjustment process of the pneumatic diaphragm control valve, the intake air volume is uneven, resulting in uneven pressure on the internal diaphragm. Especially during large-stroke adjustments, the control valve exhibits unstable regulation, leading to fluctuations in the outlet pressure of the unit.

[0004] 2. When the stroke time of the control valve does not meet the process requirements, there is no effective damping time setting and adjustment device to quickly adjust its stroke time, and the quick-opening and adjustment characteristics of the anti-surge valve cannot be satisfied.

[0005] 3. The anti-surge control valve has poor ability to overcome external resistance, and the automatic regulation system is prone to overshoot, causing fluctuations in the output pressure of the unit and resulting in changes in the operating conditions.

[0006] 4. When there is a power supply failure of the solenoid valve, there is no redundancy measure. When the solenoid valve loses power, the control valve will open fully, affecting the normal production of the main process.

[0007] 5. There is no effective way to judge the pressure of the diaphragm head of the pneumatic diaphragm control valve.

[0008] 6. When maintaining and repairing the anti-surge control valve, the exhaust noise of the control valve is relatively large, which has a certain adverse impact on the health of maintenance personnel.

[0009] 7. The air source of the positioner and the air source of the pneumatic relay are controlled by a single filter pressure reducing valve, and the auxiliary adjustment of the full-closure time of the control valve cannot be achieved.

[0010] 8. In the air circuit control loop without a quick exhaust valve, when the full - open time of the regulating valve meets the requirements, the impact force on the diaphragm head is too large, shortening the service life of the diaphragm. Summary of the Invention

[0011] In view of the above - mentioned technical problems, the present invention provides an anti - surge device, which solves the problems of uneven pressure on the internal diaphragm, non - adjustable stroke time, and inability to self - hold when the solenoid valve fails and loses power during the adjustment process of the pneumatic diaphragm regulating valve.

[0012] In order to achieve the above object, the technical solution of the present invention is as follows:

[0013] An anti - surge device includes an instrument air source. The instrument air source is respectively connected to the intake ends of a filter pressure reducing valve a and a filter pressure reducing valve b through a ball valve. The filter pressure reducing valve a is respectively connected to a sleeve - type pneumatic diaphragm regulating valve and a power - off quick - opening mechanism through a pneumatic relay. A Siemens valve positioner is installed on the sleeve - type pneumatic diaphragm regulating valve. A pressure detection mechanism is provided on the Siemens valve positioner. The air supply end of the Siemens valve positioner is connected to the outlet end of the filter pressure reducing valve b. The Siemens valve positioner is connected to the intake end of a one - way throttle valve a. The outlet end of the one - way throttle valve a is connected to the intake end of the power - off quick - opening mechanism. The outlet end of the power - off quick - opening mechanism is respectively connected to a one - way throttle valve b and a damping time setting mechanism. The one - way throttle valve b is connected to a quick exhaust valve. The damping time setting mechanism is respectively connected to the sleeve - type pneumatic diaphragm regulating valve and the quick exhaust valve. The power - using end of the power - off quick - opening mechanism is connected to a redundant UPS. The redundant UPS is connected to a DCS control system. The DCS control system is connected to the Siemens valve positioner.

[0014] A safety valve is installed on the sleeve - type pneumatic diaphragm regulating valve.

[0015] The pressure detection mechanism is a 6DR40041Q Siemens positioner pressure module.

[0016] The power - off quick - opening mechanism includes a solenoid valve.

[0017] The damping time setting mechanism is two throttle valves connected in series with each other.

[0018] A silencer a is installed in cooperation with the venting end of the pneumatic relay, and a silencer b is provided on the quick exhaust valve.

[0019] The beneficial effects of the present invention are as follows: The present invention completely solves the problems such as uneven pressure on the internal diaphragm during the adjustment process of the pneumatic diaphragm regulating valve, non-adjustable stroke time, and inability to self-hold in case of solenoid valve failure and power loss, improves the stability, accuracy and reliability of the adjustment system, and ensures the stable operation of the main equipment. The present invention can achieve fast and stable adjustment of the anti-surge valve, ensuring the stability of the adjustment system; it can ensure that the diaphragm of the pneumatic diaphragm regulating valve is not damaged, improving the service life of the regulating valve; it can cooperate with anti-surge methods such as the fixed limit or variable limit flow method of the unit to effectively prevent the occurrence of unit surge phenomenon. Brief Description of the Drawings

[0020] Figure 1 is a schematic structural diagram of the present invention.

[0021] Among them, 1 - ball valve; 2 - filter pressure reducing valve a; 3 - pneumatic relay; 4 - silencer a; 5 - Siemens valve positioner; 6 - one-way throttle valve a; 7 - sleeve type pneumatic diaphragm regulating valve; 8 - stainless steel reducer joint; 9 - throttle valve; 10 - solenoid valve; 11 - quick exhaust valve; 12 - one-way throttle valve b; 13 - silencer b; 14 - pressure detection mechanism; 15 - damping time setting mechanism; 16 - power-off quick-opening mechanism; 17 - filter pressure reducing valve b; 18 - instrument air source; 19 - safety valve; 20 - DCS control system; 21 - redundant UPS. Detailed Embodiments

[0022] To make the purpose, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below in conjunction with the specific embodiments and with reference to the accompanying drawings. It should be understood that these descriptions are exemplary and are not intended to limit the scope of the present invention. In addition, in the following description, the descriptions of well-known structures and technologies are omitted to avoid unnecessarily confusing the concepts of the present invention.

[0023] As Figure 1As shown in the figure, an anti-surge device includes an instrument air source 18. The instrument air source 18 is respectively connected to the intake ends of a filter pressure reducing valve a2 and a filter pressure reducing valve b17 through a ball valve 1. The filter pressure reducing valve a2 is respectively connected to a sleeve pneumatic diaphragm regulating valve 7 and a power-off quick-opening mechanism 16 through a pneumatic relay 3. A Siemens valve positioner 5 is installed on the sleeve pneumatic diaphragm regulating valve 7. A pressure detection mechanism 14 is provided on the Siemens valve positioner 5. The air supply end of the Siemens valve positioner 5 is connected to the outlet end of the filter pressure reducing valve b17. The Siemens valve positioner 5 is connected to the intake end of a one-way throttle valve a6. The outlet end of the one-way throttle valve a6 is connected to the intake end of the power-off quick-opening mechanism 16. The outlet end of the power-off quick-opening mechanism 16 is respectively connected to a one-way throttle valve b12 and a damping time setting mechanism 15. The one-way throttle valve b12 is connected to a quick exhaust valve 11. The damping time setting mechanism 15 is respectively connected to the sleeve pneumatic diaphragm regulating valve 7 and the quick exhaust valve 11. The power consumption end of the power-off quick-opening mechanism 16 is connected to a redundant UPS 21. The redundant UPS 21 is connected to a DCS control system 20. The DCS control system 20 is connected to the Siemens valve positioner 5. Both the one-way throttle valve a6 and the one-way throttle valve b12 are composed of FESTO one-way throttle valves, with a thread specification of GR-1 / 2, and are formed by connecting a one-way valve and a throttle valve in parallel. It is mainly used for the function of unidirectional conduction in the positive direction and throttling in the reverse direction, and performs two-way regulation on the gas path during the opening and closing process of the regulating valve. The ball valve 1 is a DN15 stainless steel double internal thread valve, mainly used for reliably cutting off the gas path during the maintenance of the regulating valve. The filter pressure reducing valve a2 and the filter pressure reducing valve b17 are ARF2000 pressure regulating filters, mainly used for stabilizing the air source pressure, and at the same time having a filtering effect on impurities such as dust and moisture in the air source. The pressure range of the quick exhaust valve 11 is 0.3 - 1.0 MPa, the interface thread is G1 / 2, the diameter of the through hole is 8 mm, and the flow rate ≥ 2.5 m 2 / min, and the commutation time ≤ 0.04 seconds. It is mainly used for when the pressure at the air supply end drops rapidly, the connection end between the air supply end and the actuator is not conducted, and the connection end of the actuator is directly conducted to the atmosphere, so that the air pressure in the diaphragm head of the pneumatic diaphragm regulating valve drops rapidly, realizing the quick opening function of the anti-surge regulating valve. The redundant UPS 21 is an uninterruptible power supply with automatic fault switching, mainly used for power supply to the solenoid valve.

[0024] As Figure 1 shown in the figure, a safety valve 19 is installed on the sleeve pneumatic diaphragm regulating valve 7. The safety valve 19 is an A28X-16T spring type safety valve, with a specification of DN15, and the outer and inner thread diameters are 20 mm and 19.5 mm respectively. It is mainly used for when the pressure in the diaphragm head of the pneumatic diaphragm regulating valve is higher than 0.8 MPa, the safety valve acts to protect the diaphragm and spring of the regulating valve from being damaged.

[0025] As Figure 1As shown, the pressure detection mechanism 14 is a 6DR40041Q Siemens positioner pressure module, mainly used to detect the supply pressure of the Siemens valve positioner 5 and the diaphragm pressure of the sleeve pneumatic diaphragm regulating valve 7. It can detect the diaphragm pressure of the pneumatic diaphragm regulating valve in real time. The sleeve pneumatic diaphragm regulating valve 7 is composed of an 811 series German ARCA pneumatic diaphragm regulating valve actuator and a sleeve valve body component, with a stroke of 100mm and no manual / automatic switching device. It is mainly used to drive the valve body component to control the outlet pressure of the unit and can overcome the influence of high differential pressure.

[0026] As Figure 1 shown, the power-off quick-opening mechanism 16 includes a solenoid valve 10. The solenoid valve 10 is a NOROREN three-way two-way solenoid valve with a supply voltage of AC 220V. It is mainly used when the control system loses power or in an emergency stop. The solenoid valve 10 quickly loses power to rapidly reduce the pressure at the control end of the pneumatic relay 3. The pneumatic relay 3 and the quick exhaust valve 11 act successively, making the regulating valve in the fully open position, featuring fast response and sensitive action.

[0027] As Figure 1 shown, the damping time setting mechanism 15 is two throttle valves 9 connected in series with each other.

[0028] As Figure 1 shown, a silencer a4 is installed on the vent end of the pneumatic relay 3, and a silencer b13 is provided on the quick exhaust valve 11.

[0029] When the present invention is in use, the instrument air source 18 is connected to the ball valve 1 through a 304 stainless steel pipe with an outer thread diameter of 20mm. The outlet of the ball valve 1 changes from DN15 to DN8 through a stainless steel reducer joint 8, connects one end of a double external thread head DN8 stainless steel pipe, and the other end connects to a 304 stainless steel ferrule tee joint. The outlet of the joint is respectively connected to a DN8 single external thread stainless steel pipe. One path is connected to an equal-diameter φ14 two-way ferrule joint, and the outlet of the joint is connected to the filter pressure reducing valve a2; the other path is connected to an equal-diameter φ14 two-way ferrule joint, and the outlet of the joint is connected to the filter pressure reducing valve b17.

[0030] In terms of intelligent control, it is mainly composed of a Siemens valve positioner 5. The other end of the equal-diameter φ14 two-way union with ferrule at the outlet of the filter pressure reducing valve b17 is connected to the stainless steel pipe with double external threads DN8 and then to the equal-diameter φ14 two-way union with ferrule at the air supply end of the single-acting Siemens valve positioner 5. The other end of the equal-diameter φ14 two-way union with ferrule is connected to the air supply end of the Siemens valve positioner 5. The control end of the Siemens valve positioner 5 is connected to the equal-diameter φ14 two-way union with ferrule, and the other end is connected to one end of the stainless steel pipe with double external threads DN8 through the equal-diameter φ14 two-way union with ferrule. The pressure detection mechanism 14 is a 6DR40041Q Siemens positioner pressure module, which is assembled with the Siemens valve positioner 5 through special bolts. The Siemens valve positioner 5 is a SIPART PS2 series intelligent electric valve positioner, mainly used for the automatic control of the anti-surge regulating valve, controlling the action of the controllable constant current device through a given signal, and having the characteristics of continuous manual and automatic control.

[0031] The installation direction of the one-way throttle valve a6 is that the throttling direction is from the air inlet direction of the control signal of the Siemens valve positioner 5, and the exhaust direction is the conduction direction of the one-way valve. The other end of the equal-diameter φ14 two-way union with ferrule and the stainless steel pipe with double external threads DN8 is connected to one end of the equal-diameter φ14 two-way union with ferrule, and the other end is connected to the air inlet side of the one-way throttle valve a6. The outlet of the one-way throttle valve a6 is connected to one end of the equal-diameter φ14 two-way union with ferrule, and the other end is connected to one end of the stainless steel pipe with double external threads DN15 and DN8.

[0032] The power-off quick-opening mechanism 16 is internally provided with a two-position three-way solenoid valve 10, and its air inlet and outlet ends are respectively connected with equal-diameter φ14 two-way unions with ferrules. The other end of the two-way union with ferrule at the air inlet end is connected to the other end of the stainless steel pipe with double external threads DN8 connected to the two-way union with ferrule. The solenoid valve 10 uses a UPS redundant power supply method, which improves the operation stability of the regulating system.

[0033] The intake end of the pneumatic relay 3 is connected to one end of an equal-diameter φ14 two-way ferrule fitting, and the other end is connected to the suspended end of a DN15 double male-threaded stainless steel pipe connected to the two-way ferrule fitting. The outlet end is connected to one end of an equal-diameter φ14 two-way ferrule fitting, and the vent end is connected to one end of an equal-diameter φ14 two-way ferrule fitting, and the other end is connected to the silencer a4. The control end is connected through an equal-diameter φ14 two-way ferrule fitting and is connected to the DN15 double male-threaded stainless steel pipe and then to one end of an equal-diameter φ14 three-way ferrule fitting. The other end of the equal-diameter φ14 two-way ferrule fitting is connected to the horizontal end of the equal-diameter φ14 three-way ferrule fitting through a DN15 double male-threaded stainless steel pipe. The pneumatic relay 3 is a SMC REGULATOR VALVE pneumatic relay with a maximum working pressure of 1.0 MPa and an output pressure range of 0.05 - 0.9 MPa. It is mainly used to increase the air volume entering the diaphragm head of the pneumatic diaphragm control valve per unit time to meet the full-closure time characteristics. At the same time, when the Siemens valve positioner 5 exhausts air, according to the size of the exhaust volume, the quick-opening or regulating characteristics of the control valve are realized, and it has the characteristics of adjustable intake air volume and uniform control.

[0034] Both ends of the damping time setting mechanism 15 are respectively connected with equal-diameter φ14 two-way ferrule fittings. The other ends of the equal-diameter φ14 two-way ferrule fittings are connected to one end of an equal-diameter φ14 three-way ferrule fitting through a DN15 double male-threaded stainless steel pipe for transition. One end of the equal-diameter φ14 three-way ferrule fitting is connected to one end of the equal-diameter φ14 three-way ferrule fitting. The damping time setting mechanism 15 consists of two throttle valves 9 connected in series. Through two-stage throttling control, the accurate control of the full-closure time of the control valve can be realized. The throttle valve 9 uses a NOROREN throttle valve with a maximum working pressure of 1.0 MPa and a maximum working temperature of 80 °C. It is mainly used for adjusting the full-closure time of the anti-surge control valve to make the action time of the control valve meet the process requirements. Through two-stage pressure regulation, the effect of accurate adjustment is achieved.

[0035] The Siemens valve positioner 5 is controlled by the DCS system 20. At the same time, the DCS system controls the on-off of the solenoid valve power supply by controlling the action of the intermediate relay. The redundant UPS power supply scheme eliminates the misoperation of the solenoid valve and improves the stability of the system operation.

[0036] Process of realizing the quick-opening characteristic:

[0037] 1. When the unit performs surge control according to methods such as fixed limit or variable limit flow method, if the compressor unit has surged, the operator immediately sets the given signal of the intelligent control device to 4 mA. The Siemens valve positioner 5 reduces the pressure at the control end of the pneumatic relay 3 through exhaust. When the pressure inside the diaphragm of the pneumatic diaphragm regulating valve 7 is higher than the pressure at the control end of the pneumatic relay 3, the gas inside the diaphragm quickly discharges through the exhaust port of the pneumatic relay 3. At the same time, the pressure of the quick exhaust device connected to the other end of the diaphragm drops rapidly. Because the pressure drop speed at the intake end of the exhaust valve inside the quick exhaust device is fast, the quick exhaust valve 11 connected to the diaphragm quickly communicates with the connection end of the silencer b13, and the gas inside the diaphragm quickly discharges through the quick exhaust valve 11, achieving the quick opening characteristic, with a time less than 2 seconds.

[0038] 2. When the compressor unit needs to be emergently shut down or a surge phenomenon occurs due to a regulating valve failure, by changing the control signal of the DCS control system 20, the intermediate relay is de-energized, cutting off the supply voltage of the solenoid valve 10. The solenoid valve 10 loses power, and the pressure of the control air circuit drops rapidly, that is, the pressure at the control end of the pneumatic relay 3 drops rapidly. When the pressure inside the diaphragm of the pneumatic diaphragm regulating valve 7 is higher than the pressure at the control end of the pneumatic relay 3, the gas inside the diaphragm quickly discharges through the exhaust port of the pneumatic relay 3. At the same time, the pressure of the quick exhaust device connected to the other end of the diaphragm drops rapidly. Because the pressure drop speed at the intake end of the exhaust valve inside the quick exhaust device is fast, the quick exhaust valve 11 connected to the diaphragm quickly communicates with the connection end of the silencer b13, and the gas inside the diaphragm quickly discharges through the quick exhaust valve 11, achieving the quick opening characteristic, with a time less than 2 seconds.

[0039] During the quick opening process, there are often phenomena that do not meet the requirements of the quick opening characteristic. By adjusting the damping time setting mechanism 15, first close one of the throttle valves 9 to 1 / 3 of the fully open position, and adjust the opening of the remaining throttle valve 9 to meet the quick opening time requirement. At the same time, during the adjustment process, if the fully open time still exceeds 2 seconds, it is necessary to check the exhaust volume of the one-way throttle valve b12, and the exhaust volume of this device should be less than or equal to the exhaust volume of the damping adjustment device.

[0040] Process of realizing the regulating characteristic:

[0041] 1. During the process of reducing the opening of the regulating valve, through the change of the given signal, the gas in the control loop realizes the effect of non-throttling during air supply through the one-way throttle valve a6; through the continuous increase of the given signal, the output pressure of the positioner continuously increases. The gas in the air source is input into the diaphragm of the pneumatic diaphragm regulating valve through the control of the pneumatic relay 3, so that the gas pressure inside the diaphragm continuously increases. When it is the same as the valve position corresponding to the given signal, the piezoelectric valve of the positioner closes, the pressure of the control air circuit remains unchanged, and the pneumatic relay 3 stops operating, realizing the regulating characteristic.

[0042] During this adjustment process, the full stroke time often fails to meet the requirement of 8 - 10 seconds, and it is necessary to adjust the pressure of the filter pressure reducing valve a2 to meet the requirement.

[0043] During the loading process, there will be a phenomenon of excessive impact on the diaphragm head. By adjusting the intake air volume of the pneumatic relay 3, smooth adjustment can be achieved.

[0044] 2. During the adjustment process of increasing the opening of the regulating valve, through the change of the given signal, the gas in the control loop realizes the throttling effect during exhaust through the one - way throttle valve a6; through the continuous decrease of the given signal, the Siemens valve positioner 5 starts to exhaust. Because the decrease amplitude of the control signal is small during the adjustment process and is approximately a continuous adjustment, the control signal of the pneumatic relay 3 is the same as the pressure of the regulating valve diaphragm head, and the pneumatic relay 3 and the quick exhaust valve 11 do not exhaust, thus realizing the adjustment characteristics.

[0045] When it is necessary to adjust the time during this adjustment process, the exhaust volume of the positioner is controlled by adjusting the adjustment knob in the one - way throttle valve a6 to meet the adjustment characteristics.

[0046] It should be understood that the above - mentioned specific embodiments of the present invention are only used for exemplary illustration or explanation of the principle of the present invention, and do not constitute a limitation to the present invention. Therefore, any modifications, equivalent replacements, improvements, etc. made without departing from the spirit and scope of the present invention shall be included within the protection scope of the present invention. In addition, the appended claims of the present invention are intended to cover all changes and modification examples falling within the scope and boundary of the appended claims, or equivalent forms of such scope and boundary.

Claims

1. A surge prevention device, characterized in that: It includes an instrument air source (18). The instrument air source (18) is respectively connected to the inlet ends of a filter pressure reducing valve a (2) and a filter pressure reducing valve b (17) through a ball valve (1). The filter pressure reducing valve a (2) is respectively connected to a sleeve pneumatic diaphragm regulating valve (7) and a power-off quick-opening mechanism (16) through a pneumatic relay (3). A Siemens valve positioner (5) is installed on the sleeve pneumatic diaphragm regulating valve (7). A pressure detection mechanism (14) is provided on the Siemens valve positioner (5). The air supply end of the Siemens valve positioner (5) is connected to the outlet end of the filter pressure reducing valve b (17). The Siemens valve positioner (5) is connected to the inlet end of a one-way throttle valve a (6). The outlet end of the one-way throttle valve a (6) is connected to the inlet end of the power-off quick-opening mechanism (16). The outlet end of the power-off quick-opening mechanism (16) is respectively connected to a one-way throttle valve b (12) and a damping time setting mechanism (15). The one-way throttle valve b (12) is connected to a quick exhaust valve (11). The damping time setting mechanism (15) is respectively connected to the sleeve pneumatic diaphragm regulating valve (7) and the quick exhaust valve (11). The power consumption end of the power-off quick-opening mechanism (16) is connected to a redundant UPS (21). The redundant UPS (21) is connected to a DCS control system (20). The DCS control system (20) is connected to the Siemens valve positioner (5); A safety valve (19) is installed on the sleeve pneumatic diaphragm regulating valve (7); The pressure detection mechanism (14) is a 6DR40041Q Siemens positioner pressure module; The power-off quick-opening mechanism (16) includes an electromagnetic valve (10); The damping time setting mechanism (15) is two throttle valves (9) connected in series with each other. A silencer a (4) is installed in cooperation with the vent end of the pneumatic relay (3). A silencer b (13) is provided on the quick exhaust valve (11).

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