A top shaft oil system for a steam turbine generator set

Abstract

This utility model relates to the field of coal-fired power generation technology and discloses a jacking oil system for a steam turbine generator set. The jacking oil system includes an oil suction pipe, a lubricating oil header, an oil tank, a first oil pump, a jacking oil header, a first jacking oil pipe, a second jacking oil pipe, an inlet pipe, and an outlet pipe. The oil suction pipe is connected to the lubricating oil header, which is connected to the oil tank. The inlet of the first oil pump is connected to the oil suction pipe via the inlet pipe, and the outlet of the first oil pump is connected to the jacking oil header via the outlet pipe. The jacking oil header is connected to the low-pressure bearing of the steam turbine generator set via the first jacking oil pipe, and the jacking oil header is connected to other bearings of the steam turbine generator set via the second jacking oil pipe. A solenoid valve is provided on the second jacking oil pipe for controlling its on / off state. This utility model has a simple structure, is easy to operate, and can switch between different oil supply strategies according to different operating conditions.

Description

Technical Field

[0001] This utility model relates to the field of coal-fired power generation technology, specifically to a jacking oil system for a steam turbine generator set. Background Technology

[0002] To improve the overall efficiency of power plants, more and more coal-fired power generating units are adopting integrated designs of extraction condensing and extraction back-pressure. These units can automatically switch operating modes according to demand. During the heating season, they can disengage the low-pressure rotor and operate in back-pressure mode to achieve efficient heating; during the non-heating season, they can engage the low-pressure rotor and operate in condensing mode to achieve efficient power generation.

[0003] When the unit switches from condensing operation to back pressure operation, the low-pressure rotor disengages while the other rotors continue to operate at high speed. Under this condition, in order to meet the support requirements of different rotors, two independent high-pressure oil jacking devices are usually required, resulting in a complex overall structure and poor operation convenience. Utility Model Content

[0004] The technical objective of this utility model is to address the shortcomings of the prior art by providing a simple, easy-to-operate, and switchable oil supply strategy for steam turbine generator sets that can adapt to different operating conditions.

[0005] The technical solution adopted in this utility model is as follows: A jacking oil system for a steam turbine generator set, the jacking oil system comprising an oil suction pipe, a lubricating oil header, an oil tank, a first oil pump, a jacking oil header, a first jacking oil pipe, a second jacking oil pipe, an oil inlet pipe, and an oil outlet pipe; The oil suction pipe is connected to the lubricating oil header, the lubricating oil header is connected to the oil tank, the inlet of the first oil pump is connected to the oil suction pipe through the oil inlet pipe, the outlet of the first oil pump is connected to the jacking oil header through the oil outlet pipe, the jacking oil header is connected to the low-pressure bearing of the turbine generator set through the first jacking oil header, and the jacking oil header is connected to the other bearings of the turbine generator set through the second jacking oil header. The second jacking oil pipe is equipped with a solenoid valve for controlling the opening and closing of the second jacking oil pipe.

[0006] The above-mentioned technical measures utilize a first oil pump to draw oil from the lubricating oil header through an oil suction pipe, pressurize and deliver it to the jacking oil header, and then supply oil to the low-pressure bearing and other bearings through the first and second jacking oil pipes respectively, thereby jacking up the corresponding rotors; by installing a solenoid valve on the second jacking oil pipe, different oil supply strategies can be switched according to different working conditions by controlling the solenoid valve.

[0007] When the unit is in condensing operation, the rotors corresponding to the low-pressure bearing and other bearings are at their rated high speeds, and the solenoid valves and the first oil pump are both closed. When the unit is in back-pressure operation, the rotor corresponding to the low-pressure bearing is at a low speed while the rotors corresponding to other bearings are at their rated high speeds, the solenoid valves are closed, and the first oil pump is open. When the unit is in start-up or shutdown mode, the rotors corresponding to the low-pressure bearing and other bearings are at a low speed, and the solenoid valves and the first oil pump are both open.

[0008] Furthermore, the oil suction pipe is sequentially equipped with a first check valve and a first ball valve.

[0009] The above-mentioned technical measures prevent oil backflow by setting a first check valve and facilitate control of the oil supply from the lubricating oil header by setting a first ball valve. Furthermore, a second ball valve is provided on the oil inlet pipe.

[0010] The above-mentioned technical measures, by setting a second ball valve, allow for maintenance of the first oil pump when the second ball valve is closed, without affecting the oil supply from the suction pipe to other structures.

[0011] Furthermore, the oil outlet pipe is sequentially equipped with a first filter screen, a first check valve, and a first manual valve.

[0012] The above-mentioned technical measures, by setting a first filter screen, can filter the oil at the outlet of the first oil pump, reduce impurities, and help reduce the wear of the low-pressure bearing and other bearings; by setting a first check valve, the oil can be prevented from flowing back to the first oil pump; by setting a first manual valve, the oil outlet pipe can be shut off in case of failure of the first oil pump or other situations, which facilitates maintenance.

[0013] Furthermore, a first bypass pipe is connected in parallel to the oil outlet pipe, and the two ends of the first bypass pipe are respectively connected to the oil inlet end and the oil outlet end of the first filter screen. A first differential pressure transmitter is provided on the first bypass pipe.

[0014] The above-mentioned technical measures, by setting a first differential pressure transmitter, can detect the pressure at the oil inlet and outlet of the first filter screen, and determine the degree of blockage based on the pressure difference. When the pressure difference is greater than the set threshold, the first differential pressure transmitter will issue an alarm signal, which will help to promptly remind staff to replace or repair the first filter screen.

[0015] Furthermore, a second bypass pipe is connected in parallel to the oil outlet pipe, and the two ends of the second bypass pipe are respectively connected to the oil inlet end and the oil outlet end of the first filter screen. A second one-way valve is provided on the second bypass pipe.

[0016] The above-mentioned technical measures involve setting up a second bypass pipe with a second check valve. When the first filter screen is clogged, the pressure at the inlet end of the second check valve is greater than the pressure at the outlet end, which will cause the second check valve to be in the open state, allowing oil to flow from the second check valve, maintaining the oil supply, and preventing the bearing from being cut off due to the complete blockage of the first filter screen.

[0017] Furthermore, the first oil pump is connected to a first electric motor.

[0018] The above-mentioned technical measures, by setting up a first electric motor, can provide driving force for the operation of the first oil pump.

[0019] Furthermore, the other bearings include at least one of medium-pressure bearings, high-pressure bearings, and generator bearings.

[0020] Furthermore, the top shaft oil system also includes a spare oil suction pipe, the oil inlet end of which is connected to the oil tank; The oil outlet end of the spare oil suction pipe is connected to the oil suction pipe; The spare oil suction pipe is equipped with a second manual valve, a front-mounted oil pump, a third manual valve, and a second check valve in sequence. The front-mounted oil pump is connected to a second electric motor.

[0021] The above-mentioned technical measures, by setting up a backup oil suction pipe, enable oil to be sucked up by a front-mounted oil pump even when the lubrication system is not started or malfunctions.

[0022] Furthermore, the jacking oil system also includes a second oil pump, the inlet of which is connected to the suction pipe via a spare inlet pipe, and the outlet of which is connected to the jacking oil main pipe via a spare outlet pipe. The backup oil inlet pipe is equipped with a third ball valve, and the backup oil outlet pipe is equipped with a second filter, a fifth check valve and a fourth manual valve in sequence. The spare oil outlet pipe is connected in parallel with a third bypass pipe. The two ends of the third bypass pipe are respectively connected to the oil inlet and oil outlet of the second filter screen. A second differential pressure transmitter is provided on the third bypass pipe. The spare oil outlet pipe is also connected in parallel with a fourth bypass pipe. The two ends of the fourth bypass pipe are respectively connected to the oil inlet and oil outlet of the second filter screen. A sixth one-way valve is provided on the fourth bypass pipe. The second oil pump is connected to a third electric motor.

[0023] The above-mentioned technical measures, by setting up a second oil pump, enable the supply of oil to the bearing to continue by switching to the second oil pump in the event of a failure or maintenance of the first oil pump.

[0024] One or more technical solutions provided by this utility model have at least the following technical effects or advantages: This invention utilizes a first oil pump to draw oil from the lubricating oil header through an oil suction pipe, pressurizes and delivers it to the jacking oil header, and then supplies oil to the low-pressure bearing and other bearings through the first and second jacking oil pipes respectively, thereby jacking up the corresponding rotors; by installing a solenoid valve on the second jacking oil pipe, different oil supply strategies can be switched according to different working conditions by controlling the solenoid valve.

[0025] When the unit is in condensing operation, the rotors corresponding to the low-pressure bearing and other bearings are at their rated high speeds, and the solenoid valves and the first oil pump are both closed. When the unit is in back-pressure operation, the rotor corresponding to the low-pressure bearing is at a low speed while the rotors corresponding to other bearings are at their rated high speeds, the solenoid valves are closed, and the first oil pump is open. When the unit is in start-up or shutdown mode, the rotors corresponding to the low-pressure bearing and other bearings are at a low speed, and the solenoid valves and the first oil pump are both open. Attached Figure Description

[0026] The accompanying drawings, which are provided to further illustrate the embodiments of the present invention and constitute a part of the present invention, do not constitute a limitation thereof. Figure 1 This is a schematic diagram of the top shaft oil system in this utility model; Among them, 1-suction pipe; 2-first oil pump; 3-jacking shaft oil header pipe; 4-first jacking shaft oil pipe; 5-second jacking shaft oil pipe; 6-inlet pipe; 7-outlet pipe; 8-low-pressure bearing; 9-solenoid valve; 10-first check valve; 11-first ball valve; 12-second ball valve; 13-first filter screen; 14-first check valve; 15-first manual valve; 16-first bypass pipe; 17-first differential pressure transmitter; 18-second bypass pipe; 19-second check valve; 20-first motor; 21-first one-way throttle valve; 22-third check valve; 23-second one-way throttle valve ; 24-Fourth check valve; 25-Medium pressure bearing; 26-High pressure bearing; 27-Generator bearing; 28-Spare suction pipe; 29-Second manual valve; 30-Pre-mounted oil pump; 31-Third manual valve; 32-Second check valve; 33-Second electric motor; 34-Second oil pump; 35-Spare inlet pipe; 36-Spare outlet pipe; 37-Third ball valve; 38-Second filter screen; 39-Fifth check valve; 40-Fourth manual valve; 41-Third bypass pipe; 42-Second differential pressure transmitter; 43-Fourth bypass pipe; 44-Sixth check valve; 45-Third electric motor. Detailed Implementation

[0027] To better understand the above-mentioned objectives, features, and advantages of this utility model, the present utility model will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be noted that, where there is no conflict, the embodiments of this utility model and the features within them can be combined with each other.

[0028] Many specific details are set forth in the following description in order to provide a full understanding of the present invention. However, the present invention may also be implemented in other ways different from those described herein. Therefore, the scope of protection of the present invention is not limited to the specific embodiments disclosed below.

[0029] Example 1 The terms "first," "second," "third," "fourth," "fifth," and "sixth" in this embodiment are used only to distinguish the components.

[0030] Reference Figure 1 This embodiment discloses a jacking oil system for a steam turbine generator set. The jacking oil system includes an oil suction pipe 1, a lubricating oil header pipe, an oil tank, a first oil pump 2, a jacking oil header pipe 3, a first jacking oil pipe 4, a second jacking oil pipe 5, an oil inlet pipe 6, and an oil outlet pipe 7. The first oil pump 2 is connected to a first electric motor 20.

[0031] The suction pipe 1 is connected to the lubricating oil header, which is connected to the oil tank. The inlet of the first oil pump 2 is connected to the suction pipe 1 via the inlet pipe 6. The outlet of the first oil pump 2 is connected to the jacking oil header 3 via the outlet pipe 7. The jacking oil header 3 is connected to the low-pressure bearing 8 of the turbine generator set via the first jacking oil pipe 4. The jacking oil header 3 is connected to the other bearings of the turbine generator set via the second jacking oil pipe 5. The other bearings include the intermediate-pressure bearing 25, the high-pressure bearing 26, and the generator bearing 27.

[0032] In this embodiment, two low-pressure bearings 8, two medium-pressure bearings 25, two high-pressure bearings 26, and two generator bearings 27 are used.

[0033] The second jacking oil pipe 5 is equipped with a solenoid valve 9 for controlling the opening and closing of the second jacking oil pipe 5.

[0034] The oil suction pipe 1 is equipped with a first check valve 10 and a first ball valve 11 in sequence.

[0035] A second ball valve 12 is installed on the oil inlet pipe 6.

[0036] The oil outlet pipe 7 is equipped with a first filter screen 13, a first one-way valve 14 and a first manual valve 15 in sequence.

[0037] A first bypass pipe 16 is connected in parallel to the oil outlet pipe 7. The two ends of the first bypass pipe 16 are respectively connected to the oil inlet end and the oil outlet end of the first filter screen 13. A first differential pressure transmitter 17 is provided on the first bypass pipe 16.

[0038] A second bypass pipe 18 is connected in parallel to the oil outlet pipe 7. The two ends of the second bypass pipe 18 are respectively connected to the oil inlet end and the oil outlet end of the first filter screen 13. A second one-way valve 19 is provided on the second bypass pipe 18.

[0039] The first bypass pipe 16 and the second bypass pipe 18 are connected in parallel.

[0040] The first jacking oil pipe 4 is sequentially equipped with a first one-way throttle valve 21 and a third one-way valve 22; The second jacking oil pipe 5 is equipped with a second one-way throttle valve 23 and a fourth one-way valve 24 in sequence.

[0041] The oil flow rate is easily adjusted by setting the first one-way throttle valve 21 and the second one-way throttle valve 23, and the oil backflow is prevented by setting the third one-way valve 22 and the fourth one-way valve 24.

[0042] The jacking oil system also includes a spare oil suction pipe 28, the oil inlet of which is connected to the oil tank; The oil outlet of the spare oil suction pipe 28 is connected to the oil suction pipe 1, and the connection is located between the first check valve 10 and the first ball valve 11. The spare oil suction pipe 28 is equipped with a second manual valve 29, a front oil pump 30, a third manual valve 31, and a second check valve 32 in sequence; The front-mounted oil pump 30 is connected to a second electric motor 33.

[0043] The jacking oil system also includes a second oil pump 34. The inlet of the second oil pump 34 is connected to the suction pipe 1 through a spare oil inlet pipe 35, and the outlet of the second oil pump 34 is connected to the jacking oil main pipe 3 through a spare oil outlet pipe 36. The backup oil inlet pipe 35 is equipped with a third ball valve 37, and the backup oil outlet pipe 36 is equipped with a second filter screen 38, a fifth check valve 39 and a fourth manual valve 40 in sequence. The spare oil outlet pipe 36 is connected in parallel with a third bypass pipe 41. The two ends of the third bypass pipe 41 are respectively connected to the oil inlet end and the oil outlet end of the second filter screen 38. A second differential pressure transmitter 42 is provided on the third bypass pipe 41. The spare oil outlet pipe 36 is also connected in parallel with a fourth bypass pipe 43. The two ends of the fourth bypass pipe 43 are respectively connected to the oil inlet end and the oil outlet end of the second filter screen 38. A sixth one-way valve 44 is provided on the fourth bypass pipe 43. Among them, the third bypass pipe 41 and the fourth bypass pipe 43 are connected in parallel.

[0044] The second oil pump 34 is connected to the third electric motor 45.

[0045] The jacking oil system also includes a controller and multiple speed sensors. The controller is connected to the speed sensors. In this embodiment, eight speed sensors are used. The eight speed sensors are respectively installed on two low-pressure bearings 8, two medium-pressure bearings 25, two high-pressure bearings 26 and two generator bearings 27 to detect the rotational speed of the corresponding rotor and send it to the controller.

[0046] The controller is also connected to solenoid valve 9, first motor 20, second motor 33, third motor 45, first differential pressure transmitter 17 and second differential pressure transmitter 42.

[0047] During the non-heating season, the unit operates in condensing mode. When the unit starts up, the speed sensors detect the speeds of the low-pressure rotor, intermediate-pressure rotor, high-pressure rotor, and generator rotor in real time and send the data to the controller. When the speeds of the low-pressure rotor, intermediate-pressure rotor, high-pressure rotor, and generator rotor are all below 1200 RPM (low-speed state), the controller opens solenoid valve 9 and the first motor 20 to supply oil to the low-pressure bearing 8, intermediate-pressure bearing 25, high-pressure bearing 26, and generator bearing 27, respectively, thus lifting the low-pressure rotor, intermediate-pressure rotor, high-pressure rotor, and generator rotor. When the speeds of the low-pressure rotor, intermediate-pressure rotor, high-pressure rotor, and generator rotor are all above 1200 RPM and are running at rated speed, the controller closes solenoid valve 9 and the first motor 20, and no oil supply is performed. When the unit stops, the speeds of the low-pressure rotor, intermediate-pressure rotor, high-pressure rotor, and generator rotor are all below 1200 RPM, and the controller opens solenoid valve 9 and the first motor 20 to supply oil to the low-pressure bearing 8, intermediate-pressure bearing 25, high-pressure bearing 26, and generator bearing 27, respectively.

[0048] During the heating season, the unit disconnects from the low-pressure rotor and switches to back-pressure operation. When the unit starts, the speeds of the low-pressure rotor, medium-pressure rotor, high-pressure rotor, and generator rotor are all below 1200 RPM (low-speed state). The controller opens solenoid valve 9 and the first motor 20 to supply oil to the low-pressure bearing 8, medium-pressure bearing 25, high-pressure bearing 26, and generator bearing 27, respectively. When the speeds of the medium-pressure rotor, high-pressure rotor, and generator rotor are all above 1200 RPM and operate at rated speeds, and the speed of the low-pressure rotor is below 1200 RPM, the controller opens the first motor 20, closes solenoid valve 9, and supplies oil to the low-pressure bearing 8. When the unit stops, the speeds of the low-pressure rotor, medium-pressure rotor, high-pressure rotor, and generator rotor are all below 1200 RPM. The controller opens solenoid valve 9 and the first motor 20 to supply oil to the low-pressure bearing 8, medium-pressure bearing 25, high-pressure bearing 26, and generator bearing 27, respectively.

[0049] The lubricating oil header and oil tank both belong to the lubricating oil system, which is a conventional lubricating oil system and will not be described in detail in this embodiment. When the lubricating oil system is not started, oil can be pumped out using the spare oil suction pipe 28.

[0050] When maintenance of the first oil pump 2 is required, close the second ball valve 12 and the first manual valve 15 to shut off the oil circuit, thus allowing maintenance to be carried out without oil leakage. At the same time, the second oil pump 34 can be turned on to continue supplying oil.

[0051] When the first filter screen 13 is severely clogged, the pressure at the inlet of the second check valve 19 will be greater than the pressure at the outlet, causing oil to flow from the second check valve 19 and continue to supply oil. At the same time, the first differential pressure transmitter 17 can detect the pressure at the inlet and outlet of the first filter screen 13 in real time and send it to the controller. The controller judges the degree of clogging of the first filter screen 13 based on the pressure difference. If the pressure difference is higher than the preset threshold, an alarm is triggered.

[0052] Example 2 The rest of the content of this embodiment is the same as that of embodiment 1, except that: Other bearings include high-pressure bearings and generator bearings.

[0053] Although preferred embodiments of the present invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of the present invention.

[0054] Obviously, those skilled in the art can make various modifications and variations to this utility model without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this utility model and their equivalents, this utility model also intends to include these modifications and variations.

Claims

1. A jacking oil system for a steam turbine generator set, characterized in that: The jacking oil system includes an oil suction pipe (1), a lubricating oil main pipe, an oil tank, a first oil pump (2), a jacking oil main pipe (3), a first jacking oil pipe (4), a second jacking oil pipe (5), an oil inlet pipe (6), and an oil outlet pipe (7). The suction pipe (1) is connected to the lubricating oil main pipe, the lubricating oil main pipe is connected to the oil tank, the inlet of the first oil pump (2) is connected to the suction pipe (1) through the inlet pipe (6), the outlet of the first oil pump (2) is connected to the jacking oil main pipe (3) through the outlet pipe (7), the jacking oil main pipe (3) is connected to the low-pressure bearing (8) of the turbine generator set through the first jacking oil pipe (4), and the jacking oil main pipe (3) is connected to the other bearings of the turbine generator set through the second jacking oil pipe (5). The second jacking pipe (5) is equipped with a solenoid valve (9) for controlling the opening and closing of the second jacking pipe (5).

2. The top shaft oil system for a steam turbine generator unit as set forth in claim 1, wherein: The oil suction pipe (1) is provided with a first check valve (10) and a first ball valve (11) in sequence.

3. The jacking oil system for a steam turbine generator set according to claim 1, characterized in that: The oil inlet pipe (6) is equipped with a second ball valve (12).

4. The jacking oil system for a steam turbine generator set according to claim 1, characterized in that: The oil outlet pipe (7) is provided with a first filter screen (13), a first one-way valve (14) and a first manual valve (15) in sequence.

5. The jacking oil system for a steam turbine generator set according to claim 4, characterized in that: The oil outlet pipe (7) is connected in parallel with a first bypass pipe (16), the two ends of the first bypass pipe (16) are respectively connected to the oil inlet end and the oil outlet end of the first filter screen (13), and a first differential pressure transmitter (17) is provided on the first bypass pipe (16).

6. The jacking oil system for a steam turbine generator set according to claim 4, characterized in that: The oil outlet pipe (7) is connected in parallel with a second bypass pipe (18). The two ends of the second bypass pipe (18) are respectively connected to the oil inlet end and the oil outlet end of the first filter screen (13). The second bypass pipe (18) is equipped with a second one-way valve (19).

7. The jacking oil system for a steam turbine generator set according to claim 1, characterized in that: The first oil pump (2) is connected to the first electric motor (20).

8. The jacking oil system for a steam turbine generator set according to claim 1, characterized in that: The other bearings include at least one of a medium-pressure bearing (25), a high-pressure bearing (26), and a generator bearing (27).

9. The jacking oil system for a steam turbine generator set according to claim 1, characterized in that: The top shaft oil system also includes a spare oil suction pipe (28), the oil inlet end of which is connected to the oil tank; The oil outlet of the spare oil suction pipe (28) is connected to the oil suction pipe (1); The spare oil suction pipe (28) is provided with a second manual valve (29), a front oil pump (30), a third manual valve (31), and a second check valve (32) in sequence. The front-mounted oil pump (30) is connected to a second electric motor (33).

10. The jacking oil system for a steam turbine generator set according to claim 1, characterized in that: The jacking oil system also includes a second oil pump (34), the inlet of which is connected to the suction pipe (1) through a spare inlet pipe (35), and the outlet of which is connected to the jacking oil main pipe (3) through a spare outlet pipe (36). The backup oil inlet pipe (35) is equipped with a third ball valve (37), and the backup oil outlet pipe (36) is equipped with a second filter screen (38), a fifth check valve (39) and a fourth manual valve (40) in sequence. The spare oil outlet pipe (36) is connected in parallel with a third bypass pipe (41). The two ends of the third bypass pipe (41) are respectively connected to the oil inlet end and the oil outlet end of the second filter screen (38). A second differential pressure transmitter (42) is provided on the third bypass pipe (41). The spare oil outlet pipe (36) is also connected in parallel with a fourth bypass pipe (43). The two ends of the fourth bypass pipe (43) are respectively connected to the oil inlet end and the oil outlet end of the second filter screen (38). A sixth one-way valve (44) is provided on the fourth bypass pipe (43). The second oil pump (34) is connected to a third electric motor (45).

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