JPH11148309A - Oil flashing device for steam turbine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To dispeuse with cleaning in a lubricating oil tank by arranging a relatively large-mesh wire gauze for trapping foreign matters and a fine-mesh wire gauze on a return oil strainer on the upstream, in an oil flashing device for keeping cleaning degree of lubricating oil at a specified value in a lubricating oil system of a steam turbine. SOLUTION: An upstream side return oil strainer 11 and a downstream side return oil strainer 12 are arranged in the flow direction of return oil flowing from a return oil tube 9 in a return oil chamber 10 of a steam turbine lubricating oil system. In this upstream side return oil strainer 11, a relatively fine-mesh wire gauze 17 with about 120 meshes is attached on the downstream- side side surface of an upstream side return oil strainer body 13, and a traditional wire gauze 15 with about 30 meshes and a punching metal 16 for breakage prevention are laminated and attached on the downstream side of the wire gauze 17. On the contrary, on the downstream side return oil strainer body 14, the wire gauze 15 and the punching metal 16 are attached. Foreign matter receivers 18, 19 are respectively arranged on the lower parts of the return oil strainer bodies 13, 14.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an oil flushing device for maintaining the cleanliness of lubricating oil in a steam turbine lubricating oil system.

[0002]

2. Description of the Related Art FIG. 3 is a diagram showing a schematic configuration of a general steam turbine lubricating oil system, and a plurality of turbines 1a,
1 b, 1 c, 1 d are connected by a turbine shaft 2, and each of the turbines 1 a to 1 d is supported by a bearing 3. Lubricating oil is supplied between the turbine shaft 2 and the bearing 3.

The above-mentioned lubricating oil is stored in a lubricating oil tank 4 and is pumped up by an oil pump 5 to pass through respective bearing lubricating pipes 7 from a lubricating mother pipe 6 having an inner pipe having an inner and outer double pipe structure. And supplied to each bearing 3 via an orifice strainer 8. Then, the lubricating oil supplied to each bearing 3 passes through the inside of the bearing 3 and is returned to the lubricating oil tank 4 via the return oil mother pipe 9 composed of the outer pipe having the inner / outer double pipe structure.

On the other hand, the lubricating oil tank 4 has a return oil chamber 10 in which the return oil mother pipe 9 is open.
In the return oil chamber 10, an upstream return oil strainer 11 and a downstream return oil strainer 12 are sequentially arranged in the lubricating oil flow direction.
Are arranged. As shown in FIG. 4, the upstream return oil strainer 11 and the downstream return oil strainer main body 13 and the downstream return oil strainer main body 14 respectively have a normal 30 mesh wire mesh 1 as shown in FIG.
5 and punch metal 16 are attached. Therefore, the lubricating oil flowing from the return oil mother pipe 9 into the return oil chamber 10 sequentially flows through the upstream return oil strainer 11 and the downstream return oil strainer 12, where large foreign matters are captured and then the lubricating oil tank 4 Collected inside.

[0005] By the way, at the time of periodic inspection of the turbine, it is necessary to remove minute foreign matter mixed into the bearing when the turbine is opened and assembled, and to remove foreign matter in the oil supply mother pipe 6 and the return oil mother pipe 9. Therefore, an oil flushing operation is performed to maintain the cleanliness of the lubricating oil at or above the specified value. This is to prevent foreign matter that passes through the coarse strainer built into the orifice strainer 8 from flowing into the turbine bearing during the operation of the turbine, thereby preventing the turbine shaft and the bearing from being damaged. .

In the conventional oil flushing, a fine flushing strainer is put into the orifice strainer 8 in the above-mentioned lubricating oil system, and the lubricating oil is passed through the orifice strainer, where foreign matter in the lubricating oil is captured. However, foreign matter in the lubricating oil flow path on the downstream side of the bearing 3 is collected in the lubricating oil tank 4 through the return oil chamber 10 in the lubricating oil tank 4 through the return oil mother pipe 9 together with the lubricating oil. That is, the return oil chamber 10 is provided with an upstream return oil strainer 11 and a downstream return oil strainer 12 to which a coarse 30-mesh wire net 15 is attached. In these return oil strainers, oil flushing is performed. The fine foreign matter inside is not captured, but flows into the lubricating oil tank 4. For this reason, a part of the foreign matter stays in the lubricating oil tank 4 and a part is pumped up again by the oil pump 5, passes through the oil supply mother pipe 6 and the bearing oil supply pipe 7, and is captured by the fine flushing strainer in the orifice strainer 8. Is done.

[0007] When the primary oil flushing operation for increasing the cleanliness of the lubricating oil to some extent by continuing such an operation is completed,
The lubricating oil tank 4 is opened, the lubricating oil is drained, and the lubricating oil tank 4 is cleaned in order to remove foreign matter therein. Then, after that, the oil pump 5 is started again to perform the secondary oil flushing operation by passing the oil through the flushing strainer.

Therefore, in assembling the turbine after the turbine is opened and disassembled by periodic inspection of the turbine, etc., in addition to the assembly period of the bearing 3, the total of the primary oil flushing period, the oil tank cleaning period, and the secondary oil flushing period is required. An indicated oil flushing period was required.

[0009]

However, it is required that the process of assembling the turbine after the turbine is opened and disassembled by periodic inspection of the turbine and the like be shortened as much as possible. Therefore, it is conceivable to shorten the oil flushing period. However, since the oil flushing can be performed only after all the bearings have been assembled, the oil flushing cannot be performed in parallel with the assembly of the bearings. In other words, the supply of lubricating oil to bearings does not have a function that can be stopped for each bearing, and it is necessary to supply oil to all bearings at the same time.Therefore, start oil flushing operation only after all bearings have been assembled. Can not.

As described above, since all the bearings must be supplied with oil at the same time, the amount of oil supplied to each bearing cannot be flowed more than the specified flow rate due to the limitation of the capacity of the oil pump or the limitation of the built-in orifice of the orifice strainer.
In addition, in order to clean the lubricating mother pipe and the bearing lubricating pipe, it is possible to improve the cleanliness by cleaning at about 1.5 to 2 times the normal flow rate, but as described above, the flow rate of the lubricating oil is reduced. It is not possible to shorten the period for cleaning the lubricating oil because it cannot be done much.

In addition, foreign matter is captured by a fine flushing strainer provided in the orifice strainer by an oil flushing operation, and when the eyes become clogged, the oil pump is stopped, the orifice strainer is washed, and the oil pump is started again. It is necessary to perform an operation to start the oil flushing operation. Because the flushing strainers of each bearing are individually clogged differently, it is necessary to stop the oil pump every time each flushing strainer is clogged. Flushing of the bearing is a waiting time.

For this reason, the time required for oil flushing becomes longer, and the cleaning of the lubricating oil tank is also performed by stopping the operation of the oil pump and removing all the lubricating oil. There is a problem that it is not possible to avoid prolongation of

As described above, it takes a long time for the cleanliness of the lubricating oil to reach the target level, which is a major cause that the number of turbine inspection days cannot be reduced.

SUMMARY OF THE INVENTION In view of the foregoing, it is an object of the present invention to provide a steam turbine oil flushing device which does not require cleaning of a lubricating oil tank and can shorten an oil flushing period.

[0015]

According to a first aspect of the present invention, there is provided an oil flushing apparatus for maintaining cleanliness of a lubricating oil in a steam turbine lubricating oil system at a specified value. At least the upstream return oil strainer of the oil strainer is provided with a wire mesh for catching foreign substances having a relatively large size and a wire mesh with a finer size than the wire mesh.

According to a second aspect of the present invention, in the first aspect of the present invention, a foreign object receiver for always catching foreign objects is provided below the return oil strainer.

According to a third aspect of the present invention, in the first or second aspect of the present invention, an oil level alarm device for detecting an oil level on the upstream side of the upstream return oil strainer in the return oil chamber is provided. It is characterized by.

According to a fourth aspect of the present invention, in the first aspect of the present invention, the return oil strainer is appropriately replaceable.

Further, the invention according to claim 5 is characterized in that, in the invention according to any one of claims 1 to 4, a normal wire mesh having relatively large eyes is 30 mesh, and a wire mesh having fine eyes is 12 mesh.
0 mesh.

[0020]

Embodiments of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a view showing a return oil chamber of a steam turbine lubricating oil system according to an embodiment of the present invention. In a return oil chamber 10, a return oil flowing from a return oil pipe 9 flows in a return direction. An upstream return oil strainer 11 and a downstream return oil strainer 12 are sequentially provided.

The upstream return oil strainer main body 13 of the upstream return oil strainer 11 is provided with a relatively fine mesh 120 mesh on the downstream side thereof, and a conventional wire mesh 17 is provided downstream of the wire mesh 17. A 30 mesh wire net 15 and a punch metal 16 for damage prevention are stacked and mounted. On the other hand, a wire mesh 15 and a punch metal 16 having a large mesh size of 30 mesh are attached to the downstream return oil strainer main body 14 as in the related art.

Foreign matter receivers 18 and 19 are provided below the upstream return oil strainer main body 13 and the downstream return oil strainer main body 14, respectively. Foreign matters caught by the respective strainers fall below the respective strainer main bodies. The foreign matter is collected by the foreign material receivers 18 and 19.

An oil level alarm device 20 is provided on the upstream side of the upstream return oil strainer 11 to constantly monitor an increase in the oil level in the return oil chamber 10 due to clogging of the upstream return oil strainer 11. ing. Thus, the lubricating oil supplied to the bearing flows into the return oil chamber 10 through the return oil pipe 9 in the same manner as that shown in FIGS. 3 and 4, and flows into the upstream return oil strainer 11 and the downstream return oil strainer 12 Through the lubricating oil tank 4.

Therefore, at the time of oil flushing, lubricating oil is returned to the upstream return oil strainer 11 in the return oil chamber 10.
In this case, fine foreign matter is also captured by the 120-mesh wire mesh 17 and the 30-mesh wire mesh 15, and the captured foreign matter falls below the upstream return oil strainer main body 13 and is collected by the foreign matter receiver 18. You. Then, the lubricating oil that has passed through the upstream return oil strainer 11 further passes through the downstream return oil strainer 12, where foreign matter is also collected.

However, during the oil flushing, foreign matter at the location of the lubricating oil flow downstream of the bearing 3 flows into the lubricating oil tank 4 and a part thereof is not pumped up again by the oil pump. It is no longer necessary to stop the oil pump during the oil flushing and at the end of the oil flushing to carry out cleaning of the lubricating oil tank.

FIG. 2A is a view showing a conventional oil flushing procedure, and FIG. 2B is a view showing an oil flushing procedure in the present invention. In FIG. This is the next oil flushing period. C is a lubricating oil tank cleaning period in the middle of each oil flushing, D is a lubricating oil tank cleaning period at the end of each oil flushing, and E is a cleaning period of the return oil strainer at the end of each oil flushing.

However, as shown in FIG. 2A, during the conventional primary and secondary oil flushing periods, the oil pump is stopped during the oil flushing and at the end of the oil flushing in order to catch and remove foreign matter. Although the inside of the lubricating oil tank is cleaned in the present invention, in the present invention, since relics are collected by relic floats 18 and 19 provided on the oil strainer bodies 13 and 14, as shown in FIG. In the meantime, only the upstream return oil strainer 11 and the downstream return oil strainer 12 are cleaned during the oil flushing or the like, and there is no need to clean the lubricating oil tank. Therefore, the oil flushing process is performed for a period F longer than the conventional process.
Can only be shortened.

Further, when the return oil strainer is replaceable, the upstream return oil strainer and the downstream return oil strainer used during the oil flushing are replaced by a separately prepared upstream return oil strainer after the completion of the oil flushing. Can be omitted, and the oil flushing period can be further reduced.

In the above embodiment, the upstream return oil strainer is provided with a fine mesh.
This may be provided on the downstream return oil strainer or on both the upstream and downstream sides.

[0031]

As described above, according to the present invention, at least the upstream return oil strainer of the return oil strainer provided in the return oil chamber of the lubricating oil tank is provided with a normal relatively large eye for capturing foreign matter. A finer metal mesh is provided along with the metal mesh, so even during oil flushing, fine foreign matter can be captured before the lubricating oil returns to the lubricating oil tank, and the cleanliness of the lubricating oil on the bearing oil supply side can be improved. In addition to the improvement, the cleaning of the lubricating oil tank can be omitted, and the primary and secondary oil flushing periods can be significantly reduced. Further, by providing the oil level alarm device, it is possible to prevent the overflow of the lubricating oil in the return oil chamber due to clogging of the return oil strainer, and it is possible to improve the safety of the oil flushing operation.
Furthermore, since there is no oil pump stop period, there is no need to stop or start the oil pump, and the operation becomes a continuous operation, so that the operation can be simplified.

[Brief description of the drawings]

FIG. 1 is a vertical sectional side view showing an embodiment of the present invention.

FIGS. 2 (a) and 2 (b) are explanatory diagrams of primary and secondary oil flushing procedures in the conventional and the present invention.

FIG. 3 is a diagram showing a conventional turbine lubrication oil system.

FIG. 4 is a diagram showing a schematic configuration of a return oil chamber of a conventional lubricating oil tank.

[Explanation of symbols]

 Reference Signs List 4 lubricating oil tank 9 return oil mother pipe 10 return oil chamber 11 upstream return oil strainer 12 downstream return oil strainer 13 upstream return oil strainer main body 14 downstream return oil strainer main body 15 30 mesh wire mesh 16 punch metal 17 120 mesh Wire mesh 20 Oil level alarm

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI B01D 29/04 530A 35/02 E

Claims (5)

[Claims] An oil flushing device for maintaining the cleanliness of a lubricating oil in a steam turbine lubricating oil system at a specified value or more, wherein at least an upstream return oil strainer of a return oil strainer provided in a return oil chamber of a lubricating oil tank. A steam turbine oil flushing device, comprising a wire mesh for catching foreign matter having a relatively large size and a wire mesh having a finer size. 2. The steam turbine oil flushing device according to claim 1, wherein a foreign matter receiver for constantly capturing foreign matter is provided below the return oil strainer. 3. The steam turbine oil flushing device according to claim 1, further comprising an oil level alarm device for detecting an oil level on the upstream side of the upstream return oil strainer in the return oil chamber. . 4. The steam turbine oil flushing device according to claim 1, wherein the return oil strainer can be replaced as needed. 5. The steam turbine oil flushing apparatus according to claim 1, wherein the normal wire mesh having a relatively large mesh is 30 mesh, and the wire mesh having a fine mesh is 120 mesh. .