Energy storage and oil supply system for large centrifugal compressor

Abstract

The utility model relates to the technical field of compressors, and discloses an energy storage oil supply system for a large centrifugal compressor, which comprises an oil tank, a main oil pump, an auxiliary oil pump, a main oil pipe, a filter, an oil cooler, a rotor system and an oil return pipe, the oil return pipe is connected with the rotor system and the oil tank; an energy storage oil supply device is arranged on the main oil pipe; the energy storage oil supply device comprises an oil storage tank and a piston arranged in the oil storage tank, the piston divides the oil storage tank into an oil storage cavity and an energy storage cavity, an elastic supporting piece is arranged in the energy storage cavity, the oil storage cavity is connected with the main oil pipe through a bypass oil inlet pipe and a bypass oil outlet pipe, and a first one-way valve is arranged on the bypass oil inlet pipe. And an electromagnetic valve is arranged on the bypass oil outlet pipe, so that a compressor rotor system can be well protected, and the stability and the safety of the system under extreme working conditions such as sudden power failure in the operation process of the compressor are improved.

Description

Technical Field

[0001] The utility model relates to the technical field of compressors, in particular to an energy storage and oil supply system for a large centrifugal compressor. Background Art

[0002] Existing large centrifugal compressors are mostly driven by a rotor system (gearbox) and an electric motor. The oil supply system consists of two systems: an auxiliary oil pump directly driven by the motor and a main oil pump driven by the main drive shaft through gear meshing. When the equipment is shut down, the main oil circuit's oil supply volume and pressure gradually decrease as the speed decreases. During this period, the auxiliary oil pump continues to operate, providing sufficient lubricating oil and pressure to lubricate the rotor system and establish an oil film. However, in the event of a sudden power outage, the auxiliary oil pump stops operating, and the main oil pump slows down along with the high-speed rotor. The oil supply volume and pressure may not meet the requirements for establishing an oil film during the entire rotor deceleration process. This is particularly true for large compressors, where the rotor has a large moment of inertia. Initially, due to high wind resistance from the impeller, the speed decelerates rapidly. Once the speed drops to a certain level, wind resistance decreases, and the rotor continues to rotate at a low speed due to the moment of inertia. This poses a significant risk of damage to the bearings and the high-speed rotor. To cope with sudden power outages, some solutions use an auxiliary oil pump with a backup power supply, introducing a complete backup battery system for the compressor. This makes the entire electrical system more complex and brings a lot of inconvenience, cost consumption and uncertainty to sites with explosion-proof equipment requirements. Utility Model Content

[0003] The purpose of the utility model is to provide an energy storage oil supply system for a large centrifugal compressor, which can well protect the compressor rotor system and improve the stability and safety of the system when the compressor encounters extreme working conditions such as sudden power failure during operation.

[0004] The above technical objectives of the present invention are achieved through the following technical solutions:

[0005] An energy storage oil supply system for a large centrifugal compressor includes an oil tank, a main oil pump, an auxiliary oil pump, a main oil pipe, a filter, an oil cooler, a rotor system, and an oil return pipe. The main oil pump and the auxiliary oil pump are located at the upstream end of the main oil pipe, the rotor system is connected to the downstream end of the main oil pipe, the oil return pipe connects the rotor system and the oil tank, and the motor drives the impeller to rotate through the rotor system; the main oil pipe is provided with an energy storage oil supply device;

[0006] The energy storage oil supply device includes an oil storage tank and a piston arranged in the oil storage tank. The piston divides the oil storage tank into an oil storage chamber and an energy storage chamber. An elastic support member is provided in the energy storage chamber. The oil storage chamber is connected to the main oil pipe through a bypass oil inlet pipe and a bypass oil outlet pipe. A first one-way valve is provided on the bypass oil inlet pipe, and a solenoid valve is provided on the bypass oil outlet pipe.

[0007] Before starting the machine, first start the auxiliary oil pump to pump the lubricating oil in the oil tank into the main oil pipe. At this time, the moving equipment is at rest. When the oil pressure in the main oil pipe rises rapidly to a certain level, the high-pressure oil in the main oil pipe enters the oil storage chamber through the first one-way valve and the bypass oil inlet pipe. The high-pressure oil in the oil storage chamber pushes the piston in the oil storage tank toward the elastic support member, which is compressed and accumulates elastic potential energy, completing the oil storage.

[0008] When the compressor starts, during the initial ramp-up phase, as the compressor transitions from a stationary state to a moving state, the rotor system bearing oil film requires more oil, and the main oil pump begins to supply oil. At this point, the oil pressure briefly drops. Due to the presence of a one-way valve, the high-pressure oil in the reservoir does not flow back into the main oil pipe.

[0009] When the entire system is powered off, the auxiliary oil pump stops supplying oil, and the solenoid valve is in the power-off open state. When the oil pressure in the main oil pipe is lower than the oil pressure in the oil tank, the lubricating oil in the oil tank enters the main oil pipe through the bypass oil outlet pipe and continues to supply oil to the rotor system, maintaining a certain oil pressure, so that the rotor maintains a certain oil film lubrication during the deceleration process and stops smoothly.

[0010] The utility model is further configured as follows: the elastic support member is a compression spring, and may also be a disc spring, a nitrogen cylinder, etc.

[0011] The utility model is further configured such that a through hole is formed on the energy storage chamber. By providing the through hole, the pressure in the energy storage chamber can be relatively balanced, and no pressure difference will be generated when the piston moves.

[0012] The utility model is further configured as follows: the through hole is connected to an oil pipe, and the other end of the oil pipe is connected to the oil tank.

[0013] When the compressor is operating normally, the oil storage tank does not supply oil to the oil circuit. Some of the lubricating oil that leaks into the energy storage chamber through the seal flows back to the oil tank through the oil pipe. At the same time, the oil pipe can also balance the air pressure.

[0014] The utility model is further configured as follows: a stop boss is provided in the energy storage chamber, and the position of the piston moving during energy storage can be limited by the stop boss to control the energy storage pressure.

[0015] The utility model is further configured as follows: the auxiliary oil pump is connected to the main oil pipe through an auxiliary oil pipe, the auxiliary oil pipe is provided with a second one-way valve, a first pressure gauge and a safety valve, and the safety valve is connected to the oil tank;

[0016] A third pressure gauge is provided on the bypass oil outlet pipe, and the third pressure gauge is located between the solenoid valve and the oil storage tank;

[0017] A second pressure gauge is provided at one end of the main oil pipe close to the rotor system.

[0018] When the oil pressure in the oil storage tank or the main oil pipe is high, the pressure can be released through the safety valve, and the lubricating oil discharged by the pressure release returns to the oil tank.

[0019] The utility model is further configured as follows: the main oil pump is connected to the main oil pipe in two ways through a first oil pipe and a second oil pipe; a third one-way valve is provided on the first oil pipe, and a stop valve is provided on the second oil pipe.

[0020] Before the compressor runs, the auxiliary oil pump is turned on and the main oil pump has not started working yet. Open the shut-off valve and the auxiliary oil pump will pump the lubricating oil into the main oil pump, which can eliminate the air in the main oil pump and ensure the normal and stable operation of the compressor in the future.

[0021] The outstanding effects of the utility model are:

[0022] Compared with the existing technology, the auxiliary oil pump is used to pump high-pressure lubricating oil into the energy storage oil supply device during startup. By adding a pressure gauge, energy storage is completed when the pressure in the energy storage device is consistent with the pressure in the oil supply pipeline, thereby completing the energy storage work conveniently and quickly.

[0023] In the event of an unexpected power outage or other emergency, the high-pressure oil in the energy storage oil supply device can continue to stably supply oil to the rotor system through the elastic potential energy of the elastic support, preventing dry wear of the bearing due to lack of oil during the shutdown of the high-moment-of-inertia rotor. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a schematic diagram of the oil circuit of the utility model;

[0025] Figure 2 It is a partial structural diagram of the energy storage and oil supply device of the present utility model.

[0026] Reference numerals: 1, oil tank; 2, main oil pump; 3, auxiliary oil pump; 4, main oil pipe; 5, rotor system; 6, oil return pipe; 7, energy storage oil supply device; 8, auxiliary oil pipe; 9, second one-way valve; 10, first pressure gauge; 11, safety valve; 12, second pressure gauge; 13, first oil pipe; 14, second oil pipe; 15, third one-way valve; 16, filter; 17, oil cooler; 18, stop valve;

[0027] 71. Oil storage tank; 72. Piston; 73. Oil storage chamber; 74. Energy storage chamber; 75. Elastic support member; 76. Bypass oil inlet pipe; 77. Bypass oil outlet pipe; 78. First one-way valve; 79. Solenoid valve; 710. Through hole; 711. Oil pipe; 712. Stop boss; 713. Third pressure gauge. DETAILED DESCRIPTION

[0028] The following embodiments are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0029] The following references Figures 1 to 2 The following describes the embodiments of the present invention:

[0030] An energy storage oil supply system for a large centrifugal compressor includes an oil tank 1, a main oil pump 2, an auxiliary oil pump 3, a main oil pipe 4, a filter 16, an oil cooler 17, a rotor system 5, and an oil return pipe 6. The main oil pump 2 is connected to the main oil pipe 4 in two ways via a first oil pipe 13 and a second oil pipe 14. The first oil pipe 13 is equipped with a third check valve 15, and the second oil pipe 14 is equipped with a shut-off valve 18. The auxiliary oil pump 3 is connected to the main oil pipe 4 via an auxiliary oil pipe 8, which is equipped with a second check valve 9, a first pressure gauge 10, and a safety valve 11. The safety valve 11 is connected to the oil tank 1.

[0031] The main oil pipe 4 is provided with an energy storage oil supply device 7;

[0032] The energy storage oil supply device 7 includes an oil storage tank 71 and a piston 72 arranged in the oil storage tank 71. The piston 72 divides the oil storage tank 71 into an oil storage chamber 73 and an energy storage chamber 74. An elastic support member 75 is provided in the energy storage chamber 74. The elastic support member 75 is a compression spring, and can also be a disc spring, a nitrogen cylinder, etc. The oil storage chamber 73 is connected to the main oil pipe 4 through a bypass oil inlet pipe 76 and a bypass oil outlet pipe 77. A first one-way valve 78 is provided on the bypass oil inlet pipe 76, and a solenoid valve 79 is provided on the bypass oil outlet pipe 77; a third pressure gauge 713 is provided on the bypass oil outlet pipe 77, and the third pressure gauge 713 is located between the solenoid valve 79 and the oil storage tank 71; a second pressure gauge 12 is provided at one end of the main oil pipe 4 close to the rotor system 5.

[0033] Preferably, a through hole 710 is formed on the energy storage chamber 74. The through hole 710 is connected to an oil pipe 711, and the other end of the oil pipe 711 is connected to the oil tank 1.

[0034] Preferably, a stop boss 712 is provided in the energy storage chamber 74 .

[0035] Working Principle: Before starting the machine, the auxiliary oil pump is activated. When the oil pressure rapidly rises to a certain level, the high-pressure oil overcomes the pressure from the elastic support and enters the oil reservoir. This simultaneously pushes the piston in the reservoir toward the elastic support. Simultaneously, the air in the spring-side chamber is discharged through the pipeline into the oil tank chamber. At this point, the solenoid valve is energized and disconnected. When the piston reaches the stop position, it stops moving. The oil circuit pressure at this point is recorded as P0. Before starting, as the auxiliary oil pump supplies oil to the reservoir, the reading on the third pressure gauge G3 increases until it matches the reading on the first pressure gauge G1, indicating that the reservoir has completed its initial oil storage.

[0036] When the subsequent oil pressure continues to rise, the high-pressure oil does not flow to the oil storage tank. When the oil pressure is greater than a certain value, the safety valve will be pushed open and flow back to the fuel tank, so that the maximum oil pressure value is maintained within the normal range. When the compressor starts, in the early stage of speed increase, since the compressor transfers from a static state to a moving state, the oil demand of the bearing oil film rises, and the main oil pump just starts to supply oil. At this time, the oil pressure will have a short-term and small decrease. Due to the existence of the check valve, the high-pressure oil in the oil storage tank does not flow back to the oil circuit. At this time, the reading (P3) of the third pressure gauge G3 is higher than the reading (P1) of the first pressure gauge G1.

[0037] Similarly, when the compressor is running normally, the oil storage tank does not supply oil to the oil circuit. Part of the lubricating oil leaked through the seal in the spring side chamber flows back into the fuel tank through the pipeline.

[0038] When the compressor is running normally, as the speed increases, the oil supply of the main oil pump increases approximately linearly. When the speed rises to a certain value, the auxiliary oil pump stops working and only the main oil pump supplies oil. At this time, the oil circuit pressure is recorded as P1, and P1 > P0. Continuing to increase the speed, since the storage tank chamber is full, at this time, too much lubricating oil will flow back to the fuel tank through the safety valve. At this time, G1 = G3. When shutting down normally, as the speed decreases, the oil supply of the main oil pump decreases linearly. When the speed decreases to the set value, the auxiliary oil pump starts to supply oil. Due to the action of the check valve and the solenoid valve, the oil storage tank does not supply oil to the main oil circuit.

[0039] When the compressor suddenly loses power, at this time the auxiliary oil pump stops supplying oil, and only the main oil pump supplies oil by relying on the inertia rotation of the rotor. When the high-speed rotor has a high speed, the load is large and it decelerates rapidly. The oil circuit pressure P continues to decrease. When it decreases to P < P0, at this time, since the solenoid valve is in the power-off and open state, the high-pressure oil supplies oil from the oil storage tank to the main oil circuit, maintaining a certain bearing oil pressure, so that the rotor maintains a certain oil film lubrication during the deceleration process and shuts down smoothly.

[0040] In addition, the energy storage pressure P0 of the oil storage tank should not be too high, otherwise it will increase the oil supply cycle during the entire shutdown process.

[0041] The oil storage capacity determines the oil supply duration of the oil storage tank when the power is suddenly cut off. Before the rotor completely stops, the oil storage capacity of the oil storage tank can meet the continuous oil supply, which is generally controlled within 90 - 120S.

[0042] The above is only the preferred implementation mode of the present invention. It should be pointed out that for those of ordinary skill in the art, without departing from the technical principle of the present invention, several improvements and modifications can be made. These improvements and modifications made under the above assumptions should also be regarded as the protection scope of the present invention.

Claims

1. An energy storage oil supply system for a large centrifugal compressor, comprising an oil tank (1), a main oil pump (2), an auxiliary oil pump (3), a main oil pipe (4), a filter (16), an oil cooler (17), a rotor system (5), and an oil return pipe (6), characterized in that: The main oil pipe (4) is provided with an energy storage oil supply device (7); The energy storage oil supply device (7) comprises an oil storage tank (71) and a piston (72) arranged in the oil storage tank (71). The piston (72) divides the oil storage tank (71) into an oil storage chamber (73) and an energy storage chamber (74). An elastic support member (75) is provided in the energy storage chamber (74). The oil storage chamber (73) is connected to the main oil pipe (4) via a bypass oil inlet pipe (76) and a bypass oil outlet pipe (77). A first one-way valve (78) is provided on the bypass oil inlet pipe (76), and a solenoid valve (79) is provided on the bypass oil outlet pipe (77).

2. The energy storage oil supply system for a large centrifugal compressor according to claim 1, characterized in that: The elastic support member (75) is a compression spring.

3. The energy storage oil supply system for a large centrifugal compressor according to claim 1, characterized in that: A through hole (710) is formed on the energy storage chamber (74).

4. The energy storage oil supply system for a large centrifugal compressor according to claim 3, characterized in that: The through hole (710) is connected to an oil pipe (711), and the other end of the oil pipe (711) is connected to the oil tank (1).

5. The energy storage oil supply system for a large centrifugal compressor according to claim 1, characterized in that: A stopping boss (712) is provided in the energy storage chamber (74).

6. The energy storage oil supply system for a large centrifugal compressor according to claim 1, characterized in that: The auxiliary oil pump (3) is connected to the main oil pipe (4) via an auxiliary oil pipe (8); a second one-way valve (9), a first pressure gauge (10) and a safety valve (11) are provided on the auxiliary oil pipe (8); and the safety valve (11) is connected to the oil tank (1); The bypass oil outlet pipe (77) is provided with a third pressure gauge (713), and the third pressure gauge (713) is located between the solenoid valve (79) and the oil storage tank (71); A second pressure gauge (12) is provided at one end of the main oil pipe (4) close to the rotor system (5).

7. The energy storage oil supply system for a large centrifugal compressor according to claim 6, characterized in that: The main oil pump (2) is connected to the main oil pipe (4) in two ways through a first oil pipe (13) and a second oil pipe (14); a third one-way valve (15) is provided on the first oil pipe (13), and a stop valve (18) is provided on the second oil pipe (14).

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