WO2018088057A1

WO2018088057A1 - Compressor and gas pumping system having compressor

Info

Publication number: WO2018088057A1
Application number: PCT/JP2017/035459
Authority: WO
Inventors: 克年小林
Original assignee: 株式会社日立製作所
Priority date: 2016-11-14
Filing date: 2017-09-29
Publication date: 2018-05-17
Also published as: JP2020029770A

Abstract

The compressor (1) has: a sidewall (17) having a suction flow passage (14) therein; a swirling flow pipe (16) connected to the sidewall (17); a stator (13) disposed on one side with respect to the swirling flow pipe (16); a bottom part (15) disposed on the other side with respect to the swirling flow pipe (16); a holding part capable of holding liquid droplets; and a discharge part capable of discharging the liquid droplets. The pressure loss that occurs when gas moves between the suction flow passage (14) and the outside of the compressor by passing through the bottom part (15) is greater than the pressure loss that occurs when the gas moves between the suction flow passage (14) and the outside of the compressor by passing through the swirling flow pipe (16).

Description

Compressor and gas pumping system having compressor

The present invention relates to a compressor and a gas pumping system having the compressor.

In a production plant that produces natural gas (process gas), a natural gas is mined by digging a well that is several thousand meters long toward the underground natural gas field.

At the beginning of the operation of the production plant, natural gas gushes out from the underground through the well due to the self-injection pressure of the natural gas field. However, for example, since the self-injection pressure attenuates after a while from operation, the natural gas ejection speed decreases and productivity decreases.

For this reason, a method of installing a compressor in a well and pumping natural gas to the ground is known. Although it is preferable from the viewpoint of improving production efficiency to install a compressor at a location closer to the natural gas field, the well base at several thousand meters underground is hot, and it is required to cool the compressor motor and the like.

Under such circumstances, a method for cooling the stator of a motor using natural gas from a natural gas field has been studied. However, since natural gas contains water and oil droplets as foreign substances, and these foreign substances may cause damage to the motor, remove these foreign substances before flowing them to the stator. Is desired.

As a method for removing foreign matter, Patent Document 1 discloses a cyclone separator that generates a swirling flow when a process gas is introduced from a gas inlet 3 into a cyclone chamber 2 and separates oil from the process gas by a centrifugal force effect. Is disclosed. The process gas from which the oil has been separated is recovered from the gas outlet 4 provided above.

JP 2013-163143 A

When removing foreign matters by the centrifugal force effect, in order to effectively separate foreign matters, it is preferable to increase the swirl flow velocity. At the same time, it is preferable that the separated foreign matter be discharged to the outside. However, when the process gas of the natural gas field is introduced from other than the gas inlet arranged so as to form the swirl flow, the swirl flow speed is reduced and the foreign matter separation efficiency is lowered. For this reason, the structure which can discharge | emit a foreign material is calculated | required, suppressing the bad influence to a swirl | vortex flow speed.
In this regard, Patent Document 1 does not mention anything.

This invention made | formed in view of the said situation, the compressor which has the side wall which has a suction flow path inside, the swirl flow piping connected to this side wall, and the stator located in one side with respect to this swirl flow piping The suction flow path and the compression have a bottom portion located on the other side with respect to the swirl flow pipe, a holding portion capable of holding droplets, and a discharge portion capable of discharging droplets. The pressure loss when moving between the outside of the machine through the bottom portion is larger than the pressure loss when moving between the suction flow path and the outside of the compressor through the swirling flow pipe. It is characterized by.

1 is an overall configuration diagram of a compressor according to Embodiment 1. FIG. FIG. 2 is a sectional view taken along line AA in FIG. 1. It is a whole block diagram of the compressor of Example 2. FIG. 6 is an overall configuration diagram of a compressor according to a third embodiment. FIG. 6 is an overall configuration diagram of a compressor according to a fourth embodiment. It is the figure observed from the B arrow direction of FIG. FIG. 6 is an overall configuration diagram of a compressor according to a fifth embodiment. It is a whole block diagram of the gas pressure feeding system which installed the compressor of each Example.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. Similar components are denoted by the same reference numerals, and the same description will not be repeated.

The various components of the present invention do not necessarily have to be composed of one member. For example, one component is composed of a plurality of members, a plurality of components are composed of one member, A part with another component is allowed to overlap each other.

FIG. 1 shows the overall configuration of the compressor 1 according to the first embodiment. The compressor 1 includes an impeller 11 as a compression unit that pressurizes and pumps process gas, a shaft 12 that is a rotating shaft of the impeller 11, and a compression mechanism unit that includes a stator 13 that applies a rotational force to the shaft 12, and a cylinder. And a liquid droplet separation part (foreign matter separation part) having a suction flow path 14, a bottom part 15, and a swirl flow pipe 16, which is a space surrounded by a side wall 17. The compressor 1 can be installed in a process gas atmosphere. A part of the suction channel 14 may surround the compression mechanism as in this embodiment.

The side wall 17 has a compression mechanism part on one side and a bottom part 15 on the other side in the cylindrical axial direction. The bottom 15 is located between the suction flow path 14 and the outside of the compressor 1. The swirl flow pipe 16 is located between the suction flow path 14 and the outside of the compressor 1, and communicates the suction flow path 14 and the outside of the compressor 1.

The side wall 17 of this embodiment is cylindrical. The suction channel 14 is arranged in a direction in which gravity acts in a direction from the impeller 11 side toward the bottom 15 side. That is, the substance in the suction flow path 14 is subjected to gravitational acceleration toward the bottom 15 side rather than the impeller 11 side.

The impeller 11, the shaft 12, and the stator 13 are arranged on one side with respect to the swirl flow pipe 16 inside the side wall 17. As will be described later, when a process gas is introduced inside the side wall 17, the stator 13 or the like that can be at a high temperature can be cooled by this process gas. Further, the bottom portion 15 is disposed on the other side with respect to the swirl flow pipe 16.

Rather than passing through the impeller 11 and moving between the suction channel 14 and the outside of the suction channel 14, the bottom 15 is passed between the suction channel 14 and the outside of the suction channel 14. The bottom portion 15 is configured so that the pressure loss during movement becomes a larger value.

The compressor 1 introduces a process gas containing droplets from the outside of the compressor 1 into the suction flow path 14 via the swirl flow pipe 16. Since the pressure loss when passing through the bottom 15 is large, the introduced process gas flows toward the impeller 11 side. The process gas reaches the impeller 11 through the space around the stator 13 and the shaft 12, is pressurized by the impeller 11, and is further pumped downstream. That is, a part of the process gas is used as a cooling gas for the motor heat generating part by flowing through a gap between the stator 13 and the shaft 12.

Moreover, the pressure loss at the time of moving through the bottom 15 through the suction channel 14 and the outside of the suction channel 14 moves through the swirling flow pipe 16 through the suction channel 14 and the outside of the suction channel 14. Greater than pressure loss. For this reason, almost all or all of the process gas around the compressor 1 enters the suction flow path 14 via the swirl flow pipe 16 and flows to the impeller 11.

FIG. 2 is a cross-sectional view taken along line AA in FIG. The swirl flow pipe 16 is connected to the side wall 17 with the substantially tangential direction of the side wall 17 as the extending direction. As a result, the process gas flows into the suction flow path 14 in a substantially tangential direction as shown by the arrow D1, and swirls along the inner periphery of the side wall 17 as shown by the arrow D2 in the suction flow path 14 to process gas. The swirling flow is generated. Since the centrifugal force acts on the droplets in the process gas by this swirling flow, the droplets move to the outer diameter side of the suction flow path 14 and adhere to the inner surface of the side wall 17. The adhering droplet forms a liquid film and descends toward the bottom 15 in the opposite direction to the impeller 11 by gravity. Accordingly, the liquid droplet proceeds toward the bottom 15.

The bottom 15 of the present embodiment is a lid that closes the lower side of the suction flow path 14. For this reason, since the process gas does not enter from the outside of the compressor 1 through the bottom portion 15, it can be effectively suppressed that the swirling flow of the process gas flowing in from the swirling flow pipe 16 is weakened.

In the case of the present embodiment, the separated droplets are held on the bottom portion 15, so that the bottom portion 15 functions as a droplet holding portion. On the other hand, since the swirl flow pipe 16 is positioned above the bottom portion 15, when the droplets are stored up to the same height as the swirl flow pipe 16, the droplets are discharged to the outside of the compressor 1 through the swirl flow pipe 16. Is done. That is, in this embodiment, the swirl flow pipe 16 functions as a droplet discharge unit.

The swirl flow pipe 16 may be connected substantially horizontally to the side wall 17, but may be connected so as to be inclined so that the side wall 17 side faces upward. If it carries out like this, since it can suppress that the droplet which should be discharged | emitted accumulates in the swirling flow piping 16, a droplet can be discharged | emitted effectively.

According to the present embodiment, the compressor 1 is provided that can discharge the droplets to the outside while effectively forming the swirl flow by the swirl flow pipe 16, that is, effectively separating the droplets in the process gas. it can.

The configuration of the present embodiment can be configured in the same manner as in the first embodiment except for the following points.
FIG. 3 is an overall configuration diagram of the compressor 1 of the present embodiment. In the present embodiment, the bottom portion 15 has an upper surface 151 and a side surface 152 extending downward from the upper surface 151. The side surface 152 is formed substantially parallel to the inner wall of the side wall 17, and in this embodiment, has a cylindrical shape similar to the shape of the side wall. Since the side surface 152 is formed to be slightly smaller than the inner wall of the side wall 17, a slit channel that functions as a droplet holding unit and a discharge unit is interposed between the side surface 152 and the side wall 17. 141 is formed. The slit channel 141 is set to a size that allows the droplet to be held between the side wall 17 and the side surface 152. A preferable range for such dimensions can be determined in advance in consideration of the viscosity of the droplets, the temperature around the compressor 1, and the like. The extension length of the side surface 152 can be set to 170 mm or more and 210 mm or less to 3 mm or less. As the droplet, water is assumed. For example, the environmental pressure is 10 MPa, the environmental temperature is 140 ° C., and the viscosity is 0.19805 mPa · s. Providing such a bottom portion 15 that can hold and discharge droplets can increase the pressure loss when passing through the slit channel 141, so that entry of process gas can be suppressed. Therefore, it is possible to suppress the process gas from flowing in from the outside of the droplet separation unit 1 through the bottom 15 side and weakening the swirling flow. In order to form such a slit channel 141, various known methods can be adopted. For example, a structure in which a rib is provided between the side surface 152 and the side wall 17 to fix the side surface 152 is conceivable.

Now, when the impeller 11 is driven and the process gas flows into the swirling flow pipe 16 and turns into swirling flow, the droplets adhere to the side wall 17 by the centrifugal force effect to form the liquid film L. The liquid film descends toward the bottom 15 due to gravity and is held in the slit channel 141. There is an upper limit to the amount of droplets that can be held in the slit channel 141, a part is held by the weight of the droplets, and the remaining part further descends the slit channel 141 and is discharged to the outside.

For example, at the beginning of the operation of the impeller 11 that pressurizes the process gas, since the droplets are not held in the slit channel 141, the process gas can pass through the slit channel 141, but the slit channel 141 , And the pressure loss is larger than the pressure loss when passing through the swirling flow pipe 16, so that the amount of inflow is kept small. For this reason, it is possible to effectively form a swirling flow even at the beginning of operation of the impeller 11. When the droplet is held in the slit channel 141, the droplet serves as a lid between the side wall 17 and the side surface 152, and the pressure loss value is further increased. Therefore, the suction through the slit channel 141 is performed. The process gas entry into the flow path 14 can be further suppressed.

According to the present embodiment, it is possible to provide the compressor 1 that has the same effects as the first embodiment and can effectively discharge the separated droplets to the outside. In addition, the pressure loss value of the slit channel 141 in the state where the droplet L does not exist can be set to four times or more the pressure loss value of the swirling flow pipe 16, for example.

The configuration of the present embodiment can be configured in the same manner as in the first or second embodiment except for the following points.
FIG. 4 is an overall configuration diagram of the compressor 1 of the present embodiment. The compressor 1 of the present embodiment has a convex portion 171 that protrudes inward from the inner surface of the side wall 17 between the impeller 11 and the swirl flow pipe 16. The convex portion 171 is provided over the entire inner surface of the side wall 17 and has a substantially annular shape in this embodiment.

Since the process gas that has flowed into the suction flow path 14 is directed to the impeller 11 located above the swirl flow pipe 16, the liquid can rise on the side wall 17 due to the force of the flow. By providing the convex portion 171, it is possible to suppress the rise of such a droplet.

According to the present embodiment, it is possible to provide the compressor 1 that has the same effects as those of the first embodiment and reduces the possibility that the droplets come into contact with the stator 13 and the like.

The configuration of the present embodiment can be configured in the same manner as any of Embodiments 1 to 3 except for the following points.

FIG. 5 is an overall configuration diagram of the compressor 1 of the present embodiment, and FIG. 6 is a diagram observed from the direction of arrow B in FIG. An obstacle 18 is provided above the swirl flow pipe 16 and between the impellers 11. The obstacle 18 has a convex portion 181 that protrudes inward from the inner surface of the side wall 17 and a partial wall 182 that blocks a part of the suction flow path 14.

The convex portion 181 can be configured in the same manner as the convex portion 171 exemplified in Example 3, and can suppress the rise of the droplet. The partial wall 182 is a structure provided in the vicinity of the side wall 17 or the central side of the suction channel 14 in the suction channel 14 when the suction channel 14 is observed along the channel direction (arrow B direction). is there. In this embodiment, it is formed in a cross shape when viewed from the flow path direction. The partial flow of the process gas can be reduced by the partial wall 182. The compression efficiency can be optimized by causing the impeller 11 to suck the process gas after decelerating the swirling flow of the process gas.

Since it is preferable to decelerate the swirling flow after the droplets are separated by the swirling flow, the obstacle 18 may be provided at a position away from the swirling flow piping 16 by, for example, 0.15 m or more.

The obstacle 18 is, for example, 5% or more, 10% or more, 15% or more, or 20% of the distance from the swirling flow pipe 16 to the impeller 11 along the flow path direction in order to sufficiently reduce the swirling flow. It may extend as described above. Further, the number of obstacles 18 is not limited to one, and a plurality of obstacles may be provided. In this way, the swirl flow can be decelerated more effectively.

According to the present embodiment, it is possible to provide the compressor 1 having the same effects as the first embodiment and improved boosting efficiency. Note that the convex portion 181 may be omitted and only the partial wall 182 may be provided.

The configuration of this embodiment can be the same as that of any of Embodiments 1 to 4 except for the following points.
FIG. 7 is an overall configuration diagram of the compressor 1 of the present embodiment. In the present embodiment, the bottom portion 15 is constituted by a valve having a bottom plate 153 that slides substantially in contact with the inner surface of the side wall 17 and that functions as a droplet holding portion, and an elastic body 154 connected to the bottom plate 153. ing. The compressor 1 has a hole 19 below the swirl flow pipe 16 that communicates with the outside of the compressor 1 and functions as a droplet discharge unit.

As the elastic body 154, for example, a spring can be employed. The elastic body 154 is adjusted so that the hole 19 is positioned below the bottom plate 153 when only the weight of the bottom plate 153 is applied.

Since the bottom plate 153 is provided so as to slide substantially on the side wall 17, the process gas that attempts to enter the compressor 1 through the hole 19 is suppressed from passing above the bottom plate 153. For this reason, a pressure loss is large and it can suppress that the swirling flow which approachs through the swirling flow piping 16 weakens. Further, when the liquid droplet starts to be held on the upper side of the bottom plate 153, even if a gap is generated between the side wall 17 and the bottom plate 153, the liquid droplet serves as a lid for that portion, and entry of the process gas can be suppressed.

Then, as the amount of droplets held on the upper side of the bottom plate 153 increases, the elastic body 153 is compressed according to the weight of the droplets, and the bottom plate 153 descends. When the weight of the droplet exceeds a predetermined value, the upper surface of the bottom plate 153 coincides with the height of the hole 19 and the droplet is discharged through the hole 19. By discharging a part or all of the droplets, the weight of the droplets held on the bottom plate 153 is reduced, so that the elastic body 154 lifts the bottom plate 153 again, and the upper surface of the bottom plate 153 is positioned above the hole 19. Will come to do.

The shape of the bottom plate 153 is not particularly limited, but may be, for example, a flat shape or a convex shape that is inclined downward toward the hole 19.

According to the present embodiment, it is possible to provide the compressor 1 that has the same effects as the first embodiment and can effectively discharge the separated droplets to the outside.

[Gas pressure feeding system]
FIG. 8 is an overall configuration diagram of the gas pressure feeding system 2 in which the compressor 1 according to the present invention exemplified in each embodiment is installed. The compressor 1 can be installed in a natural gas field 22 located in a well 21 dug to a depth of several thousand m or more, for example, 1000 m or more. The compressor 1 installed in such a place separates foreign substances in the natural gas at the droplet separator, cools the stator and the like using the natural gas, and pressurizes the natural gas with the impeller 11. Can be sent to the ground.

1 Compressor 11 Impeller (Pressure Booster)
12 Shaft 13 Stator 14 Suction channel 141 Narrow channel (holding part and discharge part)
15 Bottom portion 151 Top surface 152 Side surface 153 Bottom plate (holding portion)
154 Elastic body 16 Swirl pipe (discharge section)
17 Side wall 171 Convex part 18 Obstacle 181 Convex part 182 Partial wall 19 Hole (discharge part)
2 Gas pumping system 21 Well 22 Natural gas field

Claims

A side wall having a suction channel inside;
A swirl flow pipe connected to the side wall;
A compressor having a stator located on one side with respect to the swirl flow pipe,
A bottom portion located on the other side with respect to the swirling flow pipe;
A holding unit capable of holding a droplet;
A discharge part capable of discharging droplets,
The pressure loss when moving between the suction flow path and the outside of the compressor through the bottom portion moves between the suction flow path and the outside of the compressor through the swirl flow pipe. Compressor characterized by greater than case pressure loss.
The bottom is a lid;
The lid can function as the holding unit,
The compressor according to claim 1, wherein the swirl flow pipe can function as the discharge unit.
The compressor according to claim 2, wherein the swirl flow pipe is inclined so that the side wall side faces upward.
The bottom portion forms a slit channel between the side wall,
The compressor according to claim 1, wherein the slit channel can function as the holding unit and the discharge unit.
Furthermore, the side wall has a hole,
The bottom portion includes a bottom plate and an elastic body connected to the bottom plate,
When the weight of the bottom plate is added, the elastic body positions the bottom plate between the hole and the swirl flow pipe, and when the weight more than a predetermined value larger than the weight of the bottom plate is added, the bottom plate At the same height as the hole,
The bottom plate can function as the holding portion;
The compressor according to claim 1, wherein the hole can function as the discharge unit.
2. The compressor according to claim 1, further comprising a convex portion protruding inward from the inner surface of the side wall between the swirl flow pipe and the motor.
2. The compressor according to claim 1, further comprising: a partial wall between the swirl flow pipe and the stator that closes a central side of the suction flow path when viewed from the flow path direction of the suction flow path.
A gas pressure feeding system in which the compressor according to any one of claims 1 to 7 is installed in a gas field having a depth of 1000 m or more underground, and the pressure of the gas is increased and sent to the ground.