Seal flushing test system and method for simulating cross coupling working condition

Abstract

The invention provides a sealing flushing test system and method for simulating a cross coupling working condition. The system comprises a sealing flushing system, a simulation pump system, a cooling water system and a temperature measurement system, the sealed flushing system provides a flushing medium for the simulated sealed flushing cavity; the simulation pump system is used for simulating the normal operation state of a pump, a variable frequency motor is connected with a step-up gear box through a coupler, the step-up gear box increases the rotating speed to the working rotating speed through gear meshing and drives a simulation pump head to operate, and the operation of the simulation pump head drives a flushing medium in a medium heat exchanger to flow. Flushing the mechanical seal of the simulated sealed flushing cavity; the cooling water system cools a medium in the medium heat exchanger; the temperature measuring system measures the temperature of the sealing surface and the inlet and outlet temperature of the sealing flushing pipeline and transmits the temperature to the control system in real time. The influence of the working environment on the sealing service life is obtained by measuring the temperature of a sealing surface by adjusting parameters such as the rotating speed of a shaft system, the pressure of a sealing cavity, a sealing flushing medium and flushing types.

Description

Technical Field

[0001] The present invention belongs to the technical field of mechanical seal flushing, and relates to a mechanical seal flushing test system in a centrifugal pump, and in particular to a seal flushing test system and method for simulating cross-coupling working conditions, which is particularly suitable for test verification of seal flushing of special centrifugal pumps in the petrochemical industry. Background Art

[0002] Mechanical seals are an indispensable and important part of power machinery and equipment. The reliability of mechanical seals can not only provide guarantee for the long-term stable operation of industrial production, but also play a powerful role in environmental protection. If they are damaged at the site of use, it is very easy to cause users and equipment manufacturers to pay high maintenance costs, and the leakage of substances will cause great environmental pollution.

[0003] As the domestic petrochemical industry gradually becomes standardized, higher requirements are placed on pump products. As one of the main technical indicators, the service life of mechanical seals often becomes an important threshold for entering the market. In particular, to meet market demand, extreme parameter conditions such as power units (power greater than 700kW), speed (greater than 15000rpm), inlet pressure (greater than 3MPa), and medium temperature (greater than 150℃) place higher requirements on mechanical seals, and their service life becomes a key factor restricting the reliability of the entire unit. However, the existing factory acceptance test for seals is limited to static pressure and constant dynamic pressure tests, and does not reflect the influence of speed, pressure, flushing medium, flushing type and other parameters on the sealing performance, especially the influence on the sealing performance under the cross-coupling of more than two working conditions. Summary of the invention

[0004] In order to overcome the deficiencies in the prior art, the inventors have conducted intensive research and provided a seal flushing test system and method for simulating cross-coupling working conditions. By adjusting parameters such as shaft system speed, seal chamber pressure, seal flushing medium, flushing type, etc., and measuring the seal surface temperature, the influence of the working environment on the seal life can be obtained, and the seal design life can be improved based on this.

[0005] The technical solution provided by the present invention is as follows:

[0006] In a first aspect, a seal flushing test system for simulating a cross-coupling condition includes a seal flushing system, a simulated pump system, a cooling water system, and a temperature measurement system;

[0007] The seal flushing system includes a medium heat exchanger and a nitrogen boosting system; the medium heat exchanger is connected to the inlet and outlet of the simulated seal flushing chamber in the simulated pump system through a seal flushing pipeline to provide the simulated seal flushing chamber with a flushing medium of the test temperature and pressure; the nitrogen boosting system boosts the flushing medium in the medium heat exchanger;

[0008] The simulated pump system is used to simulate the normal operation of the pump, including a simulated pump head, a simulated seal flushing chamber, a speed-increasing gearbox, a variable frequency motor and a coupling; the variable frequency motor is connected to the speed-increasing gearbox through a coupling, and the speed-increasing gearbox increases the speed to the working speed through gear meshing, driving the simulated pump head to operate. The operation of the simulated pump head drives the flow of flushing medium in the medium heat exchanger to flush the mechanical seal of the simulated seal flushing chamber;

[0009] The cooling water system is connected to the medium heat exchanger through a cooling water pipeline, and is used to provide cooling water to the medium heat exchanger to cool the medium in the medium heat exchanger;

[0010] The temperature measurement system includes temperature transmitter I, temperature transmitter II, temperature transmitter III and control system; temperature transmitter I and temperature transmitter II are respectively installed on the seal flushing pipeline entering and flowing out of the simulated seal flushing chamber, and are used to measure and record the temperature rise of the flushing medium; the temperature measuring probe of temperature transmitter III is installed on the inner side of the simulated seal flushing chamber, and is used to measure the temperature of the mechanical seal in the simulated seal flushing chamber. The measurement data of the three temperature transmitters are transmitted to the control system through the transmission cable, and the control system monitors and records the above three temperature measurement values ​​in real time.

[0011] In a second aspect, a seal flushing test method for simulating a cross-coupling working condition adopts the seal flushing test system for simulating a cross-coupling working condition described in the first aspect, comprising:

[0012] Before the test, add lubricating oil to the speed increasing gearbox and seal flushing medium to the medium heat exchanger; introduce nitrogen into the medium heat exchanger through the nitrogen booster system until the pressure reaches the test pressure; the water supply system provides cooling water to the medium heat exchanger and lubricating oil cooler; check whether the control system signal transmission is correct;

[0013] After completing the preparation work, start the variable frequency motor, which is connected to the speed-increasing gearbox through a coupling. The speed-increasing gearbox increases the speed to the working speed through gear meshing, thereby driving the simulated pump head to run. The operation of the simulated pump head drives the flow of flushing medium in the medium heat exchanger to flush the mechanical seal of the simulated seal flushing chamber; temperature transmitter I and temperature transmitter II measure and record the temperature rise of the flushing medium; temperature transmitter III measures the temperature of the mechanical seal in the simulated seal flushing chamber, and the measurement data of the three temperature transmitters are transmitted to the control system through the transmission cable, and the control system monitors and records the above three temperature measurement values ​​in real time.

[0014] A seal flushing test system and method for simulating cross-coupling working conditions provided by the present invention has the following beneficial effects:

[0015] (1) The present invention provides a seal flushing test system and method for simulating cross-coupling working conditions, the test system includes a seal flushing system, a simulation pump system, a cooling water system and a temperature measurement system; the seal flushing system provides flushing medium to the simulated seal flushing chamber; the simulation pump system is used to simulate the normal operation of the pump, wherein the variable frequency motor is connected to the speed-increasing gearbox through a coupling, and the speed-increasing gearbox increases the speed to the working speed through gear meshing, driving the simulated pump head to run, and the operation of the simulated pump head drives the flow of flushing medium in the medium heat exchanger to flush the mechanical seal of the simulated seal flushing chamber; the cooling water system cools the medium in the medium heat exchanger; the temperature measurement system measures the sealing surface temperature and the inlet and outlet temperatures of the seal flushing pipeline, and transmits them to the DCS system in real time for recording. By adjusting the shaft system speed, seal chamber pressure, seal flushing medium, flushing type and other parameters, the seal surface temperature is measured to obtain the influence of the working environment on the seal life; the above test can be used to obtain the influence of multi-condition cross-coupling parameters on the sealing surface temperature and seal flushing volume;

[0016] (2) The present invention provides a seal flushing test system and method for simulating cross-coupling conditions. The simulated seal flushing chamber can adopt a direct flushing chamber and a tangential flushing chamber respectively, which realizes the convenient replacement of different seal flushing chambers on a simulated pump head, thereby improving the feasibility of multi-condition cross-coupling operation of the test system and method. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a structural schematic diagram of a seal flushing test system for simulating cross-coupling conditions;

[0018] Figure 2 Schematic diagram of the structure simulating the sealed flushing chamber. DETAILED DESCRIPTION

[0019] The following detailed description of the present invention will make the features and advantages of the present invention more clear and explicit.

[0020] The word “exemplary” is used exclusively herein to mean “serving as an example, example, or illustration.” Any embodiment described herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other embodiments.

[0021] The present invention provides a seal flushing test system for simulating cross-coupling working conditions, such as Figure 1 As shown, it includes four parts: sealing flushing system, simulation pump system, cooling water system and temperature measurement system.

[0022] The seal flushing system includes a medium heat exchanger 25, a nitrogen boosting system 21, a rotor flowmeter 18, and a seal flushing pipeline 16; the medium heat exchanger 25 is connected to the inlet and outlet of the simulated seal flushing chamber 7 in the simulated pump system through the seal flushing pipeline 16 to provide the simulated seal flushing chamber 7 with a flushing medium of test temperature and pressure; the nitrogen boosting system 21 introduces nitrogen into the medium heat exchanger 25 to adjust the flushing medium pressure; the rotor flowmeter 18 is installed on the seal flushing pipeline 16 to record the flushing flow under different external environments.

[0023] Preferably, the sealing flushing system also includes a filling funnel 20 and a stop valve 119. The filling funnel 20 fills the sealing system flushing medium into the medium heat exchanger 25 for flushing the mechanical seal of the simulated sealing flushing chamber (7); the stop valve 19 controls the opening and closing of the filling pipeline.

[0024] Preferably, a shut-off valve II 22, a one-way valve 23 and a pressure gauge 24 are installed on the boosting pipeline from the nitrogen boosting system 21 to the medium heat exchanger 25; the shut-off valve II 22 is used to control the on-off of the boosting pipeline; the one-way valve 23 is used to control the boosting direction to ensure that the boosting process is safe and stable; the pressure gauge 24 is used to monitor the pressure of the boosting pipeline.

[0025] The simulated pump system is mainly used to simulate the normal operation of the pump, including a simulated pump head 6, a simulated seal flushing chamber 7, a lubricating oil cooler 9, a speed-increasing gearbox 10, a variable frequency motor 12 and a coupling 11; the variable frequency motor 12 is connected to the speed-increasing gearbox 10 through the coupling 11, and the speed-increasing gearbox 10 increases the speed (3000rpm) to the working speed (20000rpm) through gear meshing, thereby driving the simulated pump head 6 to operate, and the operation of the simulated pump head 6 drives the flow of the flushing medium in the medium heat exchanger 25 to flush the mechanical seal of the simulated seal flushing chamber 7. The lubricating oil cooler (9) is used to cool the lubricating oil inside the speed-increasing gearbox (10), control the temperature inside the gearbox, and ensure smooth operation at any speed.

[0026] The cooling water system includes a water supply system 1, a cooling water pipeline 3, a rotor flowmeter 4, a pipeline valve I 2 and a pipeline valve II 5. The water supply system 1 is connected to the heat exchanger of the cooling medium heat exchanger 25 and the lubricating oil cooler 9 through the cooling water pipeline 3, and is mainly used to provide cooling water to the medium heat exchanger 25 and the lubricating oil cooler 9, and cool the medium in the medium heat exchanger 25 and the lubricating oil cooler 9 to ensure the safe and stable operation of the entire system. The rotor flowmeter 4 is installed on the cooling water pipeline 3 to monitor the flow of cooling water and ensure that the flow meets the requirements; the pipeline valve I 2 and the pipeline valve II 5 are respectively installed on the outlet pipeline and the return pipeline of the cooling water pipeline 3 to control the on-off of the cooling water pipeline.

[0027] The temperature measurement system includes a temperature transmitter I17, a temperature transmitter II 15, a temperature transmitter III 8, a transmission cable 14 and a DCS (distributed control system) system 13; the temperature transmitter I17 and the temperature transmitter II 15 are respectively installed on the seal flushing pipeline 16 entering and flowing out of the simulated seal flushing chamber 7, and are used to measure and record the temperature rise of the flushing medium; the temperature measuring probe of the temperature transmitter III8 is installed on the inner side of the simulated seal flushing chamber 7, and is used to measure the temperature of the mechanical seal in the simulated seal flushing chamber 7. The measurement data of the above three temperature transmitters are transmitted to the DCS system 13 through the transmission cable 14, and the DCS system 13 monitors and records the above three temperature measurement values ​​in real time.

[0028] The seal flushing system is connected to the simulated seal flushing chamber 7. The medium heat exchanger 25 in the seal flushing system can replace different types of media to verify the influence of different media on the surface temperature of the mechanical seal. The nitrogen booster system 21 in the seal flushing system can adjust the seal flushing pressure to verify the influence of different flushing pressures on the surface temperature of the mechanical seal. The variable frequency motor 12 can adjust the operating speed of the simulated pump head 6 accordingly by adjusting the frequency, so as to verify the influence of different operating speeds on the seal surface temperature and the seal flushing amount. The simulated seal flushing chamber 7 can adopt two types: direct flushing chamber and tangential flushing chamber, which are used to verify the influence of different flushing chamber forms on the surface temperature of the mechanical seal and the seal flushing amount.

[0029] Figure 2 The structural diagram of the simulated seal flushing chamber 7 includes a straight water inlet 71, a straight water inlet chamber 72, a tangential water outlet 73, a tangential water outlet chamber 74, a straight water outlet 75, a straight water outlet chamber 76 and a mounting bolt hole 77. The reference numeral 78 indicates the rotation direction of the medium in the chamber. The seal flushing medium enters the simulated seal flushing chamber 7 through the straight water inlet 71 and the straight water inlet chamber 72. There are two paths for the medium to flow out of the simulated seal flushing chamber 7, namely the tangential water outlet 73, the tangential water outlet chamber 74, and the straight water outlet 75, the straight water outlet chamber 76. The mounting bolt hole 77 cooperates with the bolt to tighten the simulated seal flushing chamber 7 and the simulated pump head 6. When used to compare the effects of different flushing types on the life of mechanical seals, ensure that the seal flushing medium, motor speed, and seal chamber pressure are consistent, and adjust the path of the simulated seal chamber outflow.

[0030] Before the test, fill the speed increasing gearbox 10 with lubricating oil to ensure the smooth operation of the gears; then open the stop valve 19, and fill the sealing system flushing medium into the medium heat exchanger 25 through the filling funnel 20 to flush the mechanical seal in the simulated sealing flushing chamber 7. After the filling is completed, close the stop valve 19; open the stop valve II 22, and introduce nitrogen into the medium heat exchanger 25 through the nitrogen boosting system 21. Read the pressure value through the pressure gauge 24. When the pressure reaches the test pressure, close the stop valve II 22. The one-way valve 23 can ensure the safety and stability of the boosting process; open the pipeline valves I 2 and II 5 on the outlet and return pipelines of the cooling water pipeline 3 to ensure that the water supply system 1 can provide cooling water to the medium heat exchanger 25 and the lubricating oil cooler 9 to ensure that the operating temperature is not too high. The rotor flowmeter 4 displays the flow of cooling water to ensure that the flow meets the requirements. Check whether the signal transmission of the DCS system 13 is correct.

[0031] After completing the preparation work, start the variable frequency motor 12, which is connected to the speed-increasing gearbox 10 through the coupling 11. The speed-increasing gearbox 10 increases the speed to the working speed through gear meshing, thereby driving the simulated pump head 6 to run. The operation of the simulated pump head 6 drives the flow of flushing medium in the medium heat exchanger 25 to flush the mechanical seal of the simulated seal flushing chamber 7. The rotor flowmeter 18 installed on the seal flushing pipeline 16 directly reads the flushing flow value; the temperature transmitter I17 and the temperature transmitter II15 measure and record the temperature rise of the flushing medium; the temperature transmitter III 8 measures the temperature of the mechanical seal in the simulated seal flushing chamber 7. The measurement data of the above three temperature transmitters are transmitted to the DCS system 13 through the transmission cable 14.

[0032] When used to compare the effects of different media on the life of the mechanical seal, the motor speed, the simulated seal flushing chamber pressure, and the flushing type are ensured to be consistent, and different types of media are added to the medium heat exchanger 25 .

[0033] When used to compare the effects of different rotational speeds on the life of a mechanical seal, the seal flushing medium, the simulated seal flushing chamber pressure, and the flushing type are ensured to be consistent, and the rotational speed of the variable frequency motor 12 is adjusted.

[0034] When used to compare the effects of different simulated seal flushing chamber pressures on the life of the mechanical seal, the seal flushing medium, motor speed, and flushing type are ensured to be consistent, and the pressure value of the nitrogen boosting system 21 is adjusted.

[0035] When used to compare the effects of different flushing types on the life of mechanical seals, ensure that the seal flushing medium, motor speed, and simulated seal flushing chamber pressure are consistent, and adjust the outflow path of the simulated seal chamber (direct flushing chamber, tangential flushing chamber).

[0036] The present invention has been described in detail above in conjunction with specific implementations and exemplary examples, but these descriptions cannot be understood as limiting the present invention. Those skilled in the art understand that, without departing from the spirit and scope of the present invention, a variety of equivalent substitutions, modifications or improvements may be made to the technical solution of the present invention and its implementation methods, all of which fall within the scope of the present invention. The scope of protection of the present invention shall be subject to the attached claims.

[0037] The contents not described in detail in the specification of the present invention belong to the common knowledge of those skilled in the art.

Claims

1. A seal flushing test system for simulating cross-coupling conditions, characterized in that: Including seal flushing system, simulation pump system, cooling water system and temperature measurement system; The seal flushing system comprises a medium heat exchanger (25) and a nitrogen boosting system (21); the medium heat exchanger (25) is connected to the inlet and outlet of the simulated seal flushing chamber (7) in the simulated pump system through a seal flushing pipeline (16), and provides a flushing medium of a test temperature and pressure to the simulated seal flushing chamber (7); the nitrogen boosting system (21) boosts the pressure of the flushing medium in the medium heat exchanger (25); The simulated pump system is used to simulate the normal operation of the pump, and includes a simulated pump head (6), a simulated seal flushing chamber (7), a speed increasing gear box (10), a variable frequency motor (12) and a coupling (11); the variable frequency motor (12) is connected to the speed increasing gear box (10) through the coupling (11); the speed increasing gear box (10) increases the rotation speed to the working rotation speed through gear meshing, thereby driving the simulated pump head (6) to operate; the operation of the simulated pump head (6) drives the flow of flushing medium in the medium heat exchanger (25), thereby flushing the mechanical seal of the simulated seal flushing chamber (7); The cooling water system is connected to the medium heat exchanger (25) through a cooling water pipeline (3) and is used to provide cooling water to the medium heat exchanger (25) to cool the medium in the medium heat exchanger (25); The temperature measurement system comprises a temperature transmitter I (17), a temperature transmitter II (15), a temperature transmitter III (8) and a control system (13); the temperature transmitter I (17) and the temperature transmitter II (15) are respectively installed on the sealing flushing pipeline (16) entering and flowing out of the simulated sealing flushing chamber (7), and are used to measure and record the temperature rise of the flushing medium; the temperature measuring probe of the temperature transmitter III (8) is installed on the inner side of the simulated sealing flushing chamber (7), and is used to measure the temperature of the mechanical seal in the simulated sealing flushing chamber (7); the measurement data of the three temperature transmitters are transmitted to the control system (13) through the transmission cable (14); and the control system (13) monitors and records the above three temperature measurement values ​​in real time.

2. The seal flushing test system for simulating cross-coupling conditions according to claim 1, characterized in that: A rotor flowmeter (18) is installed on the seal flushing pipeline (16) of the seal flushing system to record the flushing flow rate under different external environments.

3. The seal flushing test system for simulating cross-coupling conditions according to claim 1, characterized in that: A stop valve II (22), a one-way valve (23) and a pressure gauge (24) are installed on the pressurization pipeline from the nitrogen pressurization system (21) of the sealing flushing system to the medium heat exchanger (25); the stop valve II (22) is used to control the on-off of the pressurization pipeline, the one-way valve (23) is used to control the pressurization direction, and the pressure gauge (24) is used to monitor the pressure of the pressurization pipeline.

4. The seal flushing test system for simulating cross-coupling conditions according to claim 1, characterized in that: The seal flushing system further comprises a filling funnel (20) and a stop valve I (19). The filling funnel (20) fills the seal system flushing medium into the medium heat exchanger (25) for flushing the mechanical seal of the simulated seal flushing chamber (7); and the stop valve I (19) controls the on-off of the filling pipeline.

5. The seal flushing test system for simulating cross-coupling conditions according to claim 1, characterized in that: The simulated pump system also includes a lubricating oil cooler (9), which is used to cool the lubricating oil inside the speed-increasing gearbox (10) and control the temperature inside the speed-increasing gearbox (10) so that the gearbox can run smoothly at any speed.

6. The seal flushing test system for simulating cross-coupling conditions according to claim 5, characterized in that: The cooling water system is connected to the lubricating oil cooler (9) via a cooling water pipeline (3) and is used to provide cooling water to the lubricating oil cooler (9) to cool the medium in the lubricating oil cooler (9).

7. The seal flushing test system for simulating cross-coupling conditions according to claim 6, characterized in that: The cooling water system comprises a water supply system (1), a cooling water pipeline (3), a rotor flowmeter (4), a pipeline valve I (2) and a pipeline valve II (5); the water supply system (1) is connected to the heat exchanger of the cooling medium heat exchanger (25) and the lubricating oil cooler (9) through the cooling water pipeline (3); the rotor flowmeter (4) is installed on the cooling water pipeline (3) to monitor the flow rate of cooling water; the pipeline valve I (2) and the pipeline valve II (5) are respectively installed on the outlet pipeline and the return pipeline of the cooling water pipeline (3) to control the on-off of the cooling water pipeline.

8. The seal flushing test system for simulating cross-coupling conditions according to claim 1, characterized in that: The simulated seal flushing chamber (7) comprises a straight water inlet (71), a straight water inlet chamber (72), a tangential water outlet (73), a tangential water outlet chamber (74), a straight water outlet (75) and a straight water outlet chamber (76); the seal flushing medium enters the simulated seal flushing chamber (7) through the straight water inlet (71) and the straight water inlet chamber (72), and the medium flows out of the simulated seal flushing chamber (7) through two paths, namely the tangential water outlet (73) and the tangential water outlet chamber (74), and the straight water outlet (75) and the straight water outlet chamber (76).

9. A seal flushing test method for simulating cross-coupling conditions, characterized in that: A seal flushing test system for simulating a cross-coupling working condition according to any one of claims 1 to 8, comprising: Before the test, add lubricating oil to the speed increasing gearbox and mechanical seal flushing medium to the medium heat exchanger; introduce nitrogen into the medium heat exchanger through the nitrogen booster system until the pressure reaches the test pressure; the water supply system provides cooling water to the medium heat exchanger and lubricating oil cooler; check whether the control system signal transmission is correct; After completing the preparation work, start the variable frequency motor, which is connected to the speed-increasing gearbox through a coupling. The speed-increasing gearbox increases the speed to the working speed through gear meshing, thereby driving the simulated pump head to run. The operation of the simulated pump head drives the flow of flushing medium in the medium heat exchanger to flush the mechanical seal of the simulated seal flushing chamber; temperature transmitter I and temperature transmitter II measure and record the temperature rise of the flushing medium; temperature transmitter III measures the temperature of the mechanical seal in the simulated seal flushing chamber, and the measurement data of the three temperature transmitters are transmitted to the control system through the transmission cable, and the control system monitors and records the above three temperature measurement values ​​in real time.

10. The seal flushing test method for simulating cross-coupling conditions according to claim 9, characterized in that: When used to compare the effects of different media on the life of mechanical seals, ensure that the motor speed, simulated seal flushing chamber pressure, and flushing type are consistent, and different types of media are filled in the medium heat exchanger; When used to compare the effects of different speeds on the life of mechanical seals, ensure that the seal flushing medium, simulated seal flushing chamber pressure, and flushing type are consistent, and adjust the speed of the variable frequency motor; When used to compare the effects of different simulated seal flushing chamber pressures on the life of mechanical seals, ensure that the seal flushing medium, motor speed, and flushing type are consistent, and adjust the pressure value of the nitrogen booster system; When used to compare the effects of different flushing types on the life of mechanical seals, ensure that the seal flushing medium, motor speed, and simulated seal flushing chamber pressure are consistent, and adjust the outflow path of the simulated seal chamber.

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