JP5248447B2 - Motor pump - Google Patents

Description

  The present invention relates to a motor pump, and more particularly, to a motor pump that has a motor chamber and a pump chamber and distributes it also to a handling liquid motor chamber discharged from the pump chamber.

  The motor pump is formed by coaxially arranging a pump that sucks and discharges liquid and the like and a motor that drives the pump. For example, Patent Document 1 describes a submerged pump for liquefied gas. The submerged pump is immersed in a container in which a handling liquid such as liquefied gas is stored, and sucks and discharges the handling liquid. Note that a motor pump for handling liquid at a cryogenic temperature of about −160 ° C. is sometimes called a cryogenic pump. For example, a cryogenic pump is used for cryogenic liquefied natural gas mainly containing butane.

  Note that Patent Document 1 discloses that when the submerged pump is stopped, the pressure in the motor chamber is suddenly reduced and the liquid handled in the motor chamber is rapidly vaporized, so that a vent valve is provided in the motor chamber. Has been.

  Patent Document 2 discloses a canned motor pump in which a pump unit and a motor unit are connected via an adapter, and a handling liquid is circulated through the rotor portion of the motor. However, an auxiliary is provided between the front rotor chamber of the motor unit and the adapter. A configuration in which a pump chamber is provided is disclosed. Here, a part of the pump handling liquid is guided from the pump part to the auxiliary pump chamber, and the rear rotor chamber of the motor part and the discharge pipe of the pump part are communicated with each other by a circulation pipe, and a part of the pump handling liquid is supplied to the pump part. The discharge pipe is refluxed. By this, it is stated that prevention of gasification of liquid and prevention of deterioration due to retention are achieved.

  In Patent Document 3, in a self-circulating canned motor pump, as a method for transferring an easily polymerizable liquid in which an internal circulating liquid is heated during the operation of the pump and a polymer is generated, the easily polymerizable property introduced into the canned motor pump is disclosed. It is disclosed that the relationship between the temperature of the liquid and the temperature of the internal circulating liquid immediately after being cooled before heat generation is defined.

  As a technique related to the present invention, Patent Document 4 describes a configuration using a balance disk as a mechanism for balancing the thrust of a single suction type multi-stage pump. Here, in the upstream high-pressure balance chamber and the downstream low-pressure balance chamber, which are defined via a restriction, which is a gap between the balance disk and the surrounding wall surface, between the balance chambers via a pressure drop due to the restriction. The balance thrust force generated in the engine is balanced with the pump thrust force. The balance disc is sometimes called a balance drum.

Japanese Patent Laid-Open No. 11-230079 JP 54-158703 A JP 2007-132195 A Japanese Unexamined Patent Publication No. 7-35090

  As in the prior art, the motor can be cooled by circulating a part of the handling liquid in the motor chamber in the motor pump. By the way, if the handling liquid is polymerized around the heat generating motor, the pump may not be operated. In other words, in the case of a handling liquid that is easily polymerized, there may be an amount that is insufficient to prevent polymerization, even if the amount is sufficient for cooling.

  Therefore, it is conceivable to use the auxiliary pump described in Patent Document 2 to increase the amount of the handling liquid that circulates in the motor chamber, but in this case, the pressure of the handling liquid in the motor chamber increases. . When the pressure of the liquid handled in the motor chamber becomes high, the balance drum technique described in Patent Document 4 cannot be used as it is. That is, when the balance disk of Patent Document 4 is provided directly between the auxiliary pump chamber and the motor chamber, the liquid discharged from the auxiliary pump is discharged from the auxiliary pump rather than the pressure in the low-pressure balance chamber downstream of the balance disk. It may occur that the pressure in the motor chamber to which the liquid thus directly supplied is increased. This reduces the performance of the balance disk, leading to an increase in the size and power of the balance disk.

  The objective of this invention is providing the motor pump which can increase the quantity of the handling liquid in a motor chamber, improving the performance of a balance disk. Another object is to provide a motor pump that can suppress polymerization of the handling liquid in the motor chamber while improving the performance of the balance disk. The following means contribute to at least one of the above objects.

  A motor pump according to the present invention includes a motor chamber including a rotor having a rotating shaft and a stator disposed around the rotor, an impeller fixed to the rotating shaft, and is handled by rotating the impeller. A pump chamber that performs suction and discharge of liquid, a main discharge channel that leads most of the discharge handling liquid, which is the handling liquid discharged from the pump chamber, to the discharge port, and a discharge that is the handling liquid discharged from the pump chamber An auxiliary pump chamber that boosts at least a part of the handled liquid and discharges it as a boosted discharge liquid; and a balance drum chamber that balances at least a part of the boosted discharge liquid discharged from the auxiliary pump chamber with a thrust shaft. Circulating circulation means for returning to the suction port of the pump chamber, and at least part of the pressurized discharge liquid discharged from the auxiliary pump chamber is circulated in the motor chamber without going through the balance drum chamber, and then the main circulation Motor chamber circulation means for merging with the discharge discharge liquid of the passage, and the circulation circulation means includes a circulation path from the downstream low pressure portion of the balance drum chamber to the suction port of the pump chamber, and a motor chamber in which the pressurized discharge liquid flows. It has the partition means which isolate | separates.

  The motor pump according to the present invention may further include a main discharge throttle portion that is provided between the discharge portion of the pump chamber and the main discharge flow path and adjusts the ratio of discharge handling liquid guided to the main discharge flow path. preferable.

  In the motor pump according to the present invention, it is preferable that the motor pump includes a motor chamber restricting portion that is provided between the motor chamber and the main circulation channel and adjusts the ratio of the pressurized discharge liquid that circulates in the motor chamber.

  In the motor pump according to the present invention, it is preferable that the pump chamber performs suction and discharge using a polymerizable liquid as a handling liquid.

  In the motor pump according to the present invention, the handling liquid is preferably liquefied butane.

  With the above configuration, the motor pump includes a pump chamber, an auxiliary pump chamber, and a motor chamber. Here, most of the discharge handling liquid, which is the handling liquid discharged from the pump chamber, is guided to the discharge port, and at least a part of the boosted discharge liquid discharged from the auxiliary pump chamber is circulated by the circulation and circulation means. It returns to the suction port of the pump chamber via the balance drum chamber for balancing, and at least a part of the boosted discharge liquid discharged from the auxiliary pump chamber by the motor chamber circulation means is not passed through the balance drum chamber. And then merged with the discharge handling liquid in the main flow path. The circulation / circulation means has partition means for isolating the circulation path from the low-pressure portion on the downstream side of the balance drum chamber to the suction port of the pump chamber and the motor chamber through which the pressurized discharge liquid flows.

  A sufficient amount of handling liquid can be distributed to the motor chamber by the function of the auxiliary pump. Moreover, since the downstream low-pressure part of the balance drum chamber and the pump chamber are separated by the partitioning means, the pressure of the downstream low-pressure part can be maintained at a sufficiently low pressure, and the pressure of the upstream low-pressure part can be sufficiently high, The efficiency of the balance disk is improved. As a result, the amount of liquid handled in the motor chamber can be increased while improving the performance of the balance disk.

  Also, in the motor pump, a main discharge restrictor is provided between the discharge part of the pump chamber and the main discharge flow path to adjust the ratio of discharge handled liquid guided to the main discharge flow path. The ratio of the discharge handling liquid guided to the main discharge flow path and the handling liquid guided to the motor chamber or supplied to the balance drum can be appropriately adjusted according to the state of suction / discharge.

  Further, in the motor pump, since the motor chamber restricting portion for adjusting the ratio of the boosted discharge liquid flowing in the motor chamber is provided between the motor chamber and the main flow path, the amount of the boosted discharge liquid flowing in the motor chamber Can be adjusted to be suitable for cooling the motor chamber and suppressing polymerization of the handling liquid.

  In the motor pump, the pump chamber performs suction and discharge using a polymerizable liquid as a handling liquid. Therefore, the motor can be cooled while suppressing polymerization of the polymerizable liquid.

  In the motor pump, the handling liquid is liquefied butane. Therefore, the motor can be cooled while suppressing the polymerization of liquefied butane.

It is a figure explaining the structure of the motor pump in embodiment which concerns on this invention. FIG. 2 is a partially enlarged detail view of FIG. 1. In embodiment which concerns on this invention, it is a figure explaining the mode of the main discharge flow. In embodiment which concerns on this invention, it is a figure explaining the mode of a motor periphery flow. In embodiment which concerns on this invention, it is a figure explaining the mode of a circulating flow. It is a figure explaining the mode of the flow of handling liquid in the motor pump in a prior art. In embodiment which concerns on this invention, it is a figure explaining the mode of improvement of the quantity of the motor periphery flow.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Below, the cryogenic pump which uses the liquid mixture which has butane as the main component as a handling liquid is demonstrated as a motor pump, However, The handling liquid which has components other than butane as a main component may be sufficient. In the following description, the pump chamber is a two-stage impeller and the auxiliary pump chamber is a one-stage impeller. However, the number of impeller stages can be appropriately changed according to the use of the motor pump. In addition, the flow of the following handling liquid is only an example, and it is sufficient that there are a main discharge flow, a circulation flow, and a flow around the motor, and each specific flow method depends on the detailed specifications of the motor pump. Can be changed as appropriate. The materials, shapes, dimensions, and the like described below are examples for explanation, and can be appropriately changed so as to conform to the specifications of the motor pump.

  Below, the same code | symbol is attached | subjected to the same element in all the drawings, and the overlapping description is abbreviate | omitted. In the description in the text, the symbols described before are used as necessary.

  FIG. 1 is a cross-sectional view showing the configuration of the motor pump 10. Here, in order to facilitate understanding of the internal structure, the cross-sectional appearance is partially different from that of the longitudinal axis. The motor pump 10 uses a mixed liquid containing butane as a main component as a handling liquid. For example, the motor pump 10 is immersed in a container in which the handling liquid is stored, and the handling liquid is sucked and discharged. This is a so-called cryogenic pump.

  In the motor pump 10, the motor unit 20 and the pump unit 40 are arranged coaxially along the rotation shaft 22, and the auxiliary pump unit 60 and the balance drum unit 80 are arranged on the pump unit 40 and the motor unit 20 side. . FIG. 2 is a partially enlarged detail view around the auxiliary pump unit 60 and the balance drum unit 80.

  The motor pump 10 rotates the rotating shaft by driving the motor unit 20, thereby rotating the impeller 42 of the pump unit 40, and sucking the handling liquid from the handling liquid suction port 12 on one end side of the pump unit 40 of the pump unit 40. And it has a function which discharges a handling liquid as a discharge handling liquid from the handling liquid discharge port 14 of the other end side of the motor part 20. FIG. Transferring from the handling liquid suction port 12 toward the handling liquid discharge port 14 is the most basic function of the motor pump 10.

  In addition, the motor pump 10 boosts at least a part of the discharge handling liquid that is the handling liquid discharged from the pump part 40 by the auxiliary pump part 60 and discharges it as a boosted discharge liquid. It has a function of circulating and cooling the motor unit 20. This is the motor self-cooling function of the motor pump 10. Further, the motor pump 10 has a function of returning a part of the boosted discharge liquid to the handled liquid suction port 12 of the pump unit 40 via the balance drum unit 80 and achieving a thrust balance with respect to the rotating shaft 22. This is the thrust balance function of the motor pump 10.

  The motor unit 20 includes a rotor 24 having a rotation shaft 22 and a stator 26 disposed around the rotor 24. The motor unit 20 has a structure in which liquid does not leak to the surroundings so that a cooling handling liquid flows inside the motor unit 20. In that sense, the space through which the cooling handling liquid flows can be referred to as the motor chamber 28. The rotating shaft 22, the rotor 24, and the stator 26 are disposed inside the sealed case that constitutes the motor chamber 28.

  The main discharge flow path 30 provided outside the sealed case constituting the motor chamber 28 is a flow path for flowing most of the handling liquid discharged by the pump unit 40. The main discharge flow path 30 is the handling liquid that is the most downstream side of the outer periphery of the sealed case constituting the motor chamber 28 from the inlet through which the discharged handling liquid is introduced from the discharge chamber 44 described later in the pump section 40 through the throttle section 46. It is provided over the discharge port 14.

  The discharge handling liquid discharged from the pump unit 40 is divided into a part that flows through the main discharge channel 30 and a part that flows into the balance drum unit 80 via the auxiliary pump unit 60 as described later. Since the flow path resistance of the path 30 is smaller than the flow path resistance of the balance drum unit 80 or the like, most of the discharge handling liquid discharged from the pump unit 40 flows through the main discharge flow path 30.

  Further, the throttle portion 32 provided on the most downstream side of the sealed case constituting the motor chamber 28, that is, in the vicinity of the handling liquid discharge port 14 on the outer periphery thereof, adjusts the ratio of the pressurized discharge liquid flowing through the motor chamber 28. This is a diaphragm device having a function. That is, the throttle portion 32 is provided between the inside of the motor chamber 28 and the main discharge flow path 30 outside the motor chamber 28, and is used when returning the pressurized discharge liquid flowing in the motor chamber 28 to the main discharge flow path 30. It has a function to adjust the return amount. As a result, the amount of the pressurized discharge liquid flowing through the motor chamber 28 can be adjusted, and the cooling capacity in the motor chamber 28 and the suppression of the polymerization of the handling liquid can be appropriately performed.

  The pump unit 40 includes a handling liquid suction port 12, a two-stage impeller 42 fixed to the rotating shaft 22, and a discharge chamber 44 provided on the downstream side of the rear-stage impeller 42. Each impeller 42 can be composed of an impeller blade and a diffuser. The pump unit 40 sucks the handling liquid from the handling liquid suction port 12 by the impeller attached to the rotating shaft 22 rotated by driving of the motor unit 20 and discharges it as a pressurized discharge handling liquid. It has a function of discharging into the chamber. The pump unit 40 is also configured to prevent liquid from leaking to the surroundings so that the handling liquid flows through the pump unit 40. In that sense, the space through which the handling liquid flows can be called a pump chamber. The rotary shaft 22 and the two-stage impeller 42 are disposed inside the sealed case constituting the pump chamber.

  The throttle 46 provided between the discharge chamber 44 and the main discharge flow path 30 is a throttling device having a function of adjusting the amount of discharge handling liquid guided from the discharge chamber 44 to the main discharge flow path 30. The situation where the motor pump 10 is installed varies considerably depending on the actual site where the handling liquid is sucked and discharged, and the suction pressure and the discharge pressure also differ. The restrictor 46 has a function of adjusting the amount of the discharge handling liquid flowing through the main discharge flow path to an appropriate one according to the situation at the site. That is, according to the installation conditions of the motor pump 10, the specification of the throttle unit 46 is selected and replaced with the throttle unit 46 having an appropriate specification, so that the amount of discharge handling liquid flowing through the main discharge channel can be changed to the situation at the site. Can be adjusted to the appropriate one.

  The auxiliary pump unit 60 provided connected to the downstream side of the discharge chamber 44 includes a one-stage impeller 62 fixed to the rotary shaft 22 and a boosted discharge chamber 64 provided downstream thereof. The impeller 62 can also be composed of an impeller blade and a diffuser. The auxiliary pump unit 60 has a function of boosting a part of the discharge handling liquid discharged from the pump unit 40 and discharging it as a boosted discharge liquid. As shown in the detailed view of FIG. 2, the boosted discharge chamber 64 is a space in which the boosted discharge liquid further boosted from the pressure of the discharge chamber 44 by the impeller 62 is discharged. The auxiliary pump unit 60 also has a structure in which liquid does not leak to the surroundings so that the discharge handling liquid flows inside. In that sense, the space through which the discharge handling liquid flows can be called an auxiliary pump chamber. The sealed case constituting the auxiliary pump chamber has an integrated structure with the sealed case constituting the pump chamber. The rotary shaft 22 and the first stage impeller 62 are disposed inside the sealed case.

  Thus, the discharge handling liquid in the discharge chamber 44 is divided into a part that flows through the main discharge flow path 30 via the throttle part 46 and a part that is supplied to the auxiliary pump part 60.

  The balance drum unit 80 connected to the downstream side of the boosting discharge chamber 64 and arranged on the upstream side of the bearing 21 that supports the rotating shaft 22 includes a balance drum 82 and a balance drum chamber that is a space for storing the balance drum 82. And having a function of balancing the thrust of the rotating shaft 22 by circulating the pressurized discharge liquid around the balance drum 82 in the balance drum chamber. That is, the pump unit 40 in FIG. 1 has a function of transferring the handling liquid in one direction from the handling liquid suction port 12 toward the handling liquid discharge port 14. A pump thrust force from the outlet 14 toward the handling liquid suction port 12 is applied. The balance drum 82 has a function of generating a balance thrust force in a direction opposite to the pump thrust force.

  As shown in the detailed view of FIG. 2, in the balance drum 82, a gap between the balance drum 82 and the inner wall surface of the balance drum chamber functions as a diaphragm. Accordingly, the balance drum chamber is divided into an upstream balance chamber and a downstream balance chamber. The pressure in the upstream balance chamber becomes the high pressure side and the balance chamber on the downstream side becomes the low pressure side through the pressure drop due to the narrowing effect of the gap. Thus, the balance liquid 82 is connected to the balance drum 82 attached to the rotary shaft 22 by the difference between the high pressure of the balance chamber upstream of the balance drum 82 and the low pressure of the balance chamber downstream. A balance thrust force in a direction toward 14 is generated. The balance drum 82, the diaphragm, and the like are designed so that this balance thrust force is balanced with the previous pump thrust force.

  The low-pressure balance chamber on the downstream side of the balance drum 82 is arranged to face the bearing 21 that supports the rotary shaft 22 as described above. The place where the bearing 21 is disposed is a place where an integrated sealed case including a pump chamber, an auxiliary pump chamber, and a balance drum chamber are connected to a sealed case forming the motor chamber 28. In other words, the gap between the bearings 21 is a gap between an integrated hermetic case including a pump chamber, an auxiliary pump chamber, and a balance drum chamber, and a hermetic case forming the motor chamber 28.

  Therefore, the liquid handled in the low-pressure balance chamber of the balance drum 82 flows out through the gap between the bearings 21. The partition space 84 provided on the downstream side of the bearing 21 is a space for receiving the handling liquid flowing out from the low-pressure balance chamber of the balance drum 82 through the gap of the bearing 21.

  The partition portion 86 is a partition means that closes the gap of the bearing 21 and isolates the balance drum chamber and the motor chamber 28 in order to form the partition space 84. As a result, the pressure in the partition space 84 can be independent of the pressure in the motor chamber 28. For example, even if the pressure in the motor chamber 28 is higher than the pressure in the partition space 84, the pressure in the partition space 84 does not fluctuate.

  The circulation return channel 90 provided from the partition space 84 toward the handling liquid suction port 12 returns the handling liquid flowing out to the partition space 84 to the handling liquid suction port 12, thereby circulating the handling liquid flowing through the balance drum unit 80. This is a channel having a function. That is, the balance drum unit 80 includes a handling liquid suction port 12-a pump unit 40-an auxiliary pump unit 60-a boost discharge chamber 64-a balance drum 82-a bearing 21-a partition space 84-a circulation return channel 90-a handling liquid suction port. The handling liquid circulates in 12 routes. Each element forming this circulation path corresponds to a circulation means for circulating the handling liquid around the balance drum 82.

  In the balance drum portion 80, the passage 92 for the motor chamber that is provided not through the balance drum 82 but rather bypasses the balance drum 82 and the bearing 21 connects the boost discharge chamber 64 and the motor chamber 28, and handles the boost. The flow path has a function of supplying the liquid to the motor chamber 28 for cooling the motor. That is, the handling liquid is supplied to the motor chamber 28 via the handling liquid suction port 12 -pump unit 40 -auxiliary pump unit 60 -pressure increase discharge chamber 64 -motor chamber flow path 92. Each element forming this path corresponds to a motor chamber circulation means for supplying the handling liquid to the motor chamber 28.

  The handling liquid supplied to the motor chamber 28 in this way is a boosted handling liquid obtained by further boosting the discharged handling liquid discharged from the pump unit 40 by the auxiliary pump unit 60. In the motor chamber 28, the boosted handling liquid flows through a gap between the rotor 24 and the stator 26, flows out of the motor chamber 28 through a gap in the bearing 23, and the main discharge flow path 30. The handling liquid that has flowed joins and reaches the handling liquid discharge port 14. In addition to the clearance of the bearing 23, there is a flow that reaches the handled liquid discharge port 14 via the throttle portion 32, and the function thereof has already been described.

  Next, the flow of the handling liquid in the above configuration will be described with reference to FIG. 3, FIG. 4, and FIG. FIG. 3 is a view showing a main discharge flow 100 which is a flow of the handling liquid relating to the transfer of the handling liquid, which is a basic function of the motor pump 10. FIG. 4 is a diagram showing the motor peripheral flows 102 and 103 which are the flow of the handling liquid related to the motor self-cooling function of the motor pump 10. FIG. 5 is a diagram showing a circulating flow 104 that is a flow of the handling liquid related to the thrust balance function of the motor pump.

  FIG. 3 shows a main discharge flow 100 that is a flow of the handling liquid related to the transfer of the handling liquid in the motor pump 10. The main discharge flow 100 is a flow of the route of the handling liquid suction port 12 -the impeller 42 of the pump unit 40 -the discharge chamber 44 -the throttle unit 46 -the main discharge channel 30 -the handling liquid discharge port 14. As described above, the throttle unit 46 is a throttle device having a function of adjusting the amount of discharge handling liquid guided from the discharge chamber 44 to the main discharge channel 30. The restricting portion 46 can be called a main discharge restricting portion in order to distinguish from the restricting portion 32 provided between the motor chamber 28 and the main discharge flow path 30.

  FIG. 4 shows a motor peripheral flow 102 that is a flow of the handling liquid related to motor self-cooling in the motor pump 10. The motor peripheral flow 102 is a flow of the handling liquid that circulates in the motor chamber, and can be called a motor chamber circulation flow in that sense. The flow around the motor 102 includes the handling liquid suction port 12 -the pump unit 40 -the auxiliary pump unit 60 -the boost discharge chamber 64 -the flow path 92 for the motor chamber -the motor chamber 28 -around the rotor 24 and the stator 26 -bearing 23- This is a flow of the route of the handling liquid discharge port 14. As described above, the motor chamber 28 is supplied with the boosted handling liquid in which the discharge handling liquid pressurized by the two-stage impeller 42 of the pump unit 40 is further pressurized by the impeller 62 of the auxiliary pump unit 60.

  A part of the motor peripheral flow 102 becomes a motor peripheral flow 103 that passes through the throttle portion 32. As described above, the throttle unit 32 is a throttle device having a function of adjusting the ratio of the pressurized discharge liquid flowing through the motor chamber 28. The restricting portion 32 can be referred to as a motor chamber restricting portion when distinguished from the restricting portion 46 provided between the discharge chamber 44 and the main discharge flow path 30.

  FIG. 5 shows a circulating flow 104 that is a flow of the handling liquid related to the thrust balance in the motor pump 10. The circulating flow 104 is a route of the handling liquid suction port 12 -pump unit 40 -auxiliary pump unit 60 -pressurizing discharge chamber 64 -balance drum 82 -bearing 21 -partition space 84 -circulation return channel 90 -handling liquid suction port 12. It is a flow. This flow is returned to the handling liquid suction port 12 via the circulation return flow path 90 without passing through the motor chamber 28 because the partition space 84 and the motor chamber 28 are separated by the partition portion 86.

  The operational effects of the above configuration will be described in comparison with the prior art. FIG. 6 is a diagram illustrating an example of a configuration of a conventional motor pump 110 that does not include the auxiliary pump unit 60, the partition unit 86, and the throttle units 32 and 46. In the motor pump 110, the motor unit 20 and the pump unit 40 are coaxially disposed along the rotation shaft 22, and the balance drum unit 112 is disposed on the pump unit 40 and the motor unit 20 side. The motor pump 110 also has a handling liquid transfer function, a motor cooling function, and a thrust balance function.

  There are two flows of the handling liquid in the motor pump 110. That is, the main discharge flow 100 related to the handling liquid transfer function and the circulation flow 114 related to the function of both motor cooling and thrust balance. The main discharge flow 100 is the same as that described with reference to FIG. 3 except that the main discharge flow 100 is not provided with the throttle 46. That is, the flow has the same function as that described with reference to FIG. 3 except that it does not have the function of adjusting the amount of discharge handling liquid guided from the discharge chamber 44 to the main discharge flow path 30.

  In the motor pump 110, the handling liquid pressurized by the pump unit 40 is supplied into the motor chamber 28 through the balance drum unit 112. The handling liquid that passes through and reaches the handling liquid discharge port 14 outside the motor unit 20 is close to the pressure pressurized by the pump unit 40. Due to the pressure difference, the pressurized handling liquid enters the motor chamber 28 through the gap between the sealed cases forming the motor chamber 28. The throttle unit 114 is a throttle device such as an orifice provided to moderately suppress the intrusion. In FIG. 6, the flow of the handling liquid flowing into the motor chamber 28 via the throttle portion 114 and the bearing 23 is indicated by a white arrow.

  The circulating flow 114 is a route of the handling liquid suction port 12 -pump unit 40 -balance drum 82 -bearing 21 -motor chamber 28 -rotor 24 and stator 26 -circulation return flow path 120 -handling liquid discharge port 14. It is a flow. Here, the handling liquid pressurized by the impeller 42 of the pump unit 40 flows around the balance drum 82 and is reduced in pressure to achieve a thrust balance. Then, the handling liquid reduced in pressure by the balance drum 82 is supplied into the motor chamber 28 via the bearing 21, cools the motor, and then returns to the handling liquid discharge port 14 through the circulation return channel 120. In this manner, the motor cooling is performed by the circulating flow 114 together with the thrust balance.

  With reference to the prior art of FIG. 6, the motor pump 10 having the configuration of FIG. 1 has the following operational effects.

  The pressure of the handling liquid supplied into the motor chamber 28 can be increased, whereby the flow rate of the handling liquid supplied into the motor chamber 28 can be increased. This effect is due to the provision of the auxiliary pump unit 60.

  For example, in FIG. 6 of the prior art, the pressure of the handling liquid in the motor chamber 28 is the pressure reduced by the balance drum portion 112 at the highest point and the pressure at the handling liquid suction port 12 at the lowest point. . On the other hand, in the configuration of FIG. 1, a handling liquid having a pressure increased by the impeller 62 of the auxiliary pump unit 60 after being pressurized by the two-stage impeller 42 of the pump unit 40 is supplied to the motor chamber 28. The

  Thus, since the pressure of the handling liquid in the motor chamber 28 can be increased, vaporization of the handling liquid in the motor chamber 28 can be suppressed. Moreover, the damage of each component by vaporization of a handling liquid can be suppressed, and the fall of pump performance can be suppressed. Further, since the amount of the handling liquid into the motor chamber 28 can be increased, the motor cooling capacity can be improved, and the polymerization of the handling liquid can be suppressed together with the increase in the flow rate.

  FIG. 7 is a diagram illustrating an example of an increase in the handling liquid flow rate in the flow around the motor. The horizontal axis in FIG. 7 represents the magnitude of the motor power, and the vertical axis represents the flow rate around the motor. The solid line is the case of the configuration of FIG. 1, and the broken line is the case of the configuration of FIG. As shown in FIG. 7, in the configuration of FIG. 1, the flow rate of the handling liquid supplied into the motor chamber 28 can be increased by several tens of percent compared to the conventional technique.

  Next, the differential pressure that is the difference between the upstream pressure and the downstream pressure of the balance drum 82 can be increased. In this operation, a partition space 84 is provided by the provision of the auxiliary pump section 60 and the partition section 86, and the handling liquid is returned from the partition space 84 to the handling liquid suction port 12 through the circulation return channel 90. Depending on configuration.

  For example, in FIG. 6 of the prior art, the pressure of the handling liquid upstream of the balance drum 82 is a pressure pressurized by the two-stage impeller 42 of the pump unit 40, and the handling liquid downstream of the balance drum 82 The pressure is the pressure of the handling liquid in the motor chamber 28. The minimum value of the pressure of the handling liquid in the motor chamber 28 is the pressure at the handling liquid suction port 12. On the other hand, in the configuration of FIG. 1, the pressure of the handling liquid on the upstream side of the balance drum 82 is the pressure further increased by the auxiliary pump unit 60 with respect to the pressure pressurized by the two-stage impeller 42 of the pump unit 40. The pressure of the handling liquid on the downstream side of the balance drum 82 is the pressure at the handling liquid suction port 12.

  Thus, since the differential pressure, which is the difference between the upstream pressure and the downstream pressure of the balance drum 82, can be increased, the performance of the balance drum 82 is improved, and even a small balance drum 82 can exhibit sufficient thrust balance capability. . Thereby, the cost reduction of the balance drum 82 and the power consumed by the balance drum 82 can be reduced.

  Furthermore, the pressure at the bearing 23 can be increased. This is based on the fact that the auxiliary pump unit 60 is provided and the pressure in the motor chamber 28 can be increased by supplying the handling liquid to the motor chamber 28 without passing through the balance drum 82. For example, in FIG. 6 of the prior art, since the pressure of the handling liquid in the bearing 23 is due to the handling liquid entering the motor chamber 28 from the main discharge flow path 30 side, the pressure is applied by the two-stage impeller 42 of the pump unit 40. It becomes the magnitude | size which deducted the pressure drop in the throttle part 114 from the pressed pressure. On the other hand, in the configuration of FIG. 1, the pressure in the motor chamber 28 is higher than the pressure in the main discharge flow path 30, so the pressure of the liquid handled in the bearing 23 is increased by the two-stage impeller 42 of the pump unit 40. The increased pressure is further increased by the auxiliary pump unit 60.

  Thus, since the pressure of the handling liquid at the bearing 23 can be increased, and the flow rate of the motor-circulating flow 102 can be increased as described above, the cooling effect of the bearing 23 by the handling liquid can be improved. The life of the bearing 23 can be extended.

  The motor pump according to the present invention has a motor chamber and a pump chamber, and can be used for a motor pump that circulates also in a handling liquid motor chamber discharged from the pump chamber. For example, it can be used for cryogenic pumps, submerged pumps, canned pumps and the like.

  10, 110 Motor pump, 12 Handling liquid suction port, 14 Handling liquid discharge port, 20 Motor part, 21, 23 Bearing, 22 Rotating shaft, 24 Rotor, 26 Stator, 28 Motor chamber, 30 Main discharge flow path, 32 , 46, 114 Restriction section, 40 Pump section, 42, 62 Impeller, 44 Discharge chamber, 60 Auxiliary pump section, 64 Boost discharge chamber, 80, 112 Balance drum section, 82 Balance drum, 84 Partition space, 86 Partition section, 90 , 120 Circulation return flow path, 92 Motor chamber flow path, 100 Main discharge flow, 102, 103 Motor rotation flow, 104, 114 Circulation flow.

Claims (5)

A motor chamber including a rotor having a rotating shaft and a stator disposed around the rotor;
A pump chamber having an impeller fixed to a rotating shaft and performing suction and discharge of a handling liquid by rotating the impeller;
A main discharge flow path that guides most of the discharge handling liquid, which is the handling liquid discharged from the pump chamber, to the discharge port;
An auxiliary pump chamber for boosting at least a part of the discharge handling liquid, which is the handling liquid discharged from the pump chamber, and discharging it as a boosted discharge liquid;
Circulating circulation means for returning at least a part of the pressurized discharge liquid discharged from the auxiliary pump chamber to the suction port of the pump chamber via a balance drum chamber for thrust balance of the rotating shaft;
Motor chamber circulation means for circulating at least a part of the boosted discharge liquid discharged from the auxiliary pump chamber into the motor chamber without going through the balance drum chamber, and then merging with the discharge handling liquid in the main flow path;
With
Circulation and distribution means
A motor pump comprising partition means for isolating a circulation path from a low pressure portion on the downstream side of the balance drum chamber to a suction port of the pump chamber and a motor chamber through which the pressurized discharge liquid flows. The motor pump according to claim 1,
A motor pump comprising a main discharge throttle portion that is provided between a discharge portion of a pump chamber and a main discharge flow path and adjusts a ratio of discharge handling liquid guided to the main discharge flow path. The motor pump according to claim 1,
A motor pump, comprising: a motor chamber restricting portion that is provided between the motor chamber and the main flow passage and adjusts a ratio of the pressurized discharge liquid flowing through the motor chamber. The motor pump according to claim 1,
The pump chamber is a motor pump that performs suction and discharge using a polymerizable liquid as a handling liquid. The motor pump according to claim 4, wherein
A motor pump characterized in that the liquid handled is liquefied butane.

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