JP2007085310A - Submersible motor pump - Google Patents

Abstract

PROBLEM TO BE SOLVED To reduce the outer diameter of a water-sealed submerged motor pump.
A heat exchanger (13) is connected to a discharge side of a pump section (11) and connected to a pumping pipe (4) at one end, and a straight tubular discharge pipe (82) including a discharge channel (83) through which the pumped liquid passes. The heat transfer tube group 84 is provided in the discharge passage 83 and through which the primary coolant passes. A straight tubular primary coolant outlet pipe 81 extending along the pump portion 11 is provided to connect the primary coolant outlet 26c from the motor frame 26 covering the entire length of the submerged motor 12 and the inlet side of the heat transfer tube group 84. It has been. Inside the peripheral wall portion 26 a of the motor frame 26, there is provided a primary coolant channel 26 b having one end connected to the primary coolant inlet 26 c into the motor frame 26. A straight tubular primary coolant inlet pipe 80 extending along the pump unit 11 is provided, which connects the outlet side of the heat transfer tube group 84 and the other end of the primary coolant channel 26.
[Selection] Figure 1

Description

  The present invention relates to a submerged motor pump, and more particularly to a water-sealed submerged motor pump in which a cooling liquid of a submerged motor is sealed against pumping liquid.

  A submerged motor pump is known which is installed in a protective tube and suspended and used for discharging liquefied natural gas stored in underground rocks or discharging bottom water. In particular, when the pumped liquid is liquefied natural gas or the like and is corrosive, a water-sealed submerged motor pump in which the cooling liquid of the submerged motor is sealed against the pumped liquid is used. This water-sealed submersible motor pump includes a water-sealed circulation type that forcibly circulates the coolant of the submersible pump to a heat exchanger installed on the ground, and a heat exchanger for cooling the coolant of the submerged pump. Is roughly divided into a water-sealed enclosure type provided in the submerged motor pump itself.

  As a water-sealed submerged motor pump, a configuration in which a heat exchanger is arranged in series with respect to the pump and the submerged motor is known. For example, in Patent Document 1, a helical heat transfer tube through which the primary coolant of a submerged motor passes is arranged on the discharge port side of the pump, and the pumped liquid is used as a secondary coolant. A motor pump is disclosed. In the submerged motor pump of Patent Document 1, piping for circulating the primary coolant between the heat transfer tube and the submerged motor is provided around the submerged motor.

JP 2002-130191 A

  However, when a pipe for circulating the primary coolant between the heat transfer tube and the submerged motor is provided around the submerged motor as in the submerged motor pump described in Patent Document 1, the submerged motor pump The outer diameter of becomes larger. Therefore, it cannot be used in a protective tube with a small inner diameter. Further, in the submerged motor pump described in Patent Document 1, the helical heat transfer tube is arranged in the flow of the pumped liquid, so that the loss head due to the flow velocity in the tube is increased, and the efficiency is reduced accordingly.

  In view of such a conventional problem, an object of the present invention is to reduce the outer diameter of a water-sealed submersible motor pump. Another object of the present invention is to reduce the head loss due to the flow velocity in the pipe in a water-sealed submersible motor pump.

  The present invention relates to a pump unit, a submerged motor for driving the pump unit arranged in series with the pump unit, a primary coolant sealed in a motor frame of the submerged motor, and the pump unit. In a submerged motor pump comprising a heat exchanger for exchanging heat with a secondary coolant that is a pumped liquid, the heat exchanger has one end connected to the discharge side of the pump unit and the other end lifted. A straight tubular discharge pipe that is connected to a liquid pipe and has a discharge flow path through which pumped liquid discharged from the pump unit passes, and a heat transfer pipe group that is piped in the discharge flow path and through which the primary cooling liquid passes, The motor frame covers the entire length of the submerged motor and connects the primary coolant outlet from the motor frame and the inlet side of the heat transfer tube group, and extends straight along the pump portion. Of the outlet pipe and the peripheral wall of the motor frame A primary coolant flow path formed at one end so as to extend in the length direction of the peripheral wall portion, one end of which is connected to a primary coolant inlet into the motor frame, an outlet side of the heat transfer tube group, and the primary cooling A submerged motor pump comprising a straight tubular primary cooling liquid inlet pipe extending along the pump portion, connected to the other end of the liquid flow path.

  Since the primary coolant flow path is formed inside the peripheral wall of the motor frame, piping for circulating the primary coolant between the submerged motor and the heat exchanger must be arranged around the submerged motor. In addition, the outer diameter of the submerged motor can be reduced over its entire length. In addition, since the primary coolant outlet pipe and the primary coolant inlet pipe arranged between the submerged motor and the heat exchanger are both straight pipes extending along the pump section, the outer diameter of the pump section is also minimized. The Therefore, the submerged motor pump of the present invention can be used by being able to reduce the outer diameter over the entire length direction and through a protective tube having a smaller inner diameter. In addition, since the motor frame covers the entire length of the submerged motor, the heat conversion efficiency is high, and the cooling liquid can be guided to the lowermost part of the submerged motor through the primary coolant flow path, thereby enabling efficient cooling.

  Specifically, the primary coolant is pressurized by rotating in conjunction with the drive shaft of the submerged motor, and the primary coolant outlet, the primary coolant outlet pipe, and the heat transfer tube group are rotated from within the motor frame. A rotating body that circulates the primary coolant in a flow path that returns to the motor frame through the primary coolant inlet pipe, the primary coolant path, and the primary coolant inlet.

  The heat transfer tube group is disposed in the discharge flow channel, has a straight tube shape extending in the flow direction of the pumped liquid, and an end portion on the submerged pump side is connected to the primary coolant outlet tube. A plurality of forward-side heat transfer tubes, a straight tube disposed in the discharge flow path and extending along the flow direction of the pumped liquid, and an end portion on the submerged pump side is the primary coolant inlet pipe A plurality of return-side heat transfer tubes connected to each other, and a first coolant common tube to which ends of the outward-side heat transfer tubes and the return-side heat transfer tubes opposite to the liquid pump are connected. Since both the forward-side heat transfer tube and the return-side heat transfer tube arranged in the discharge flow channel are straight pipes extending in the flow direction of the pumped liquid, the loss head due to the flow velocity in the tube can be reduced.

  More specifically, the heat transfer tube group includes a second coolant common pipe in which an end portion on the submerged pump side of the plurality of forward path side heat transfer tubes and the primary coolant outlet pipe are connected, and A third coolant common pipe to which ends of the plurality of return-side heat transfer tubes on the submerged pump side and the primary coolant inlet pipe are connected.

  The submerged motor may include a plurality of sets of stators and rotors arranged in series in the common motor frame. By arranging a plurality of sets of stators and rotors in series in a common motor frame, it is possible to increase the output of the submerged motor without increasing the outer diameter.

  In this case, an intermediate bearing disposed in the motor frame and supporting the drive shaft between the pair of the stator and the rotor adjacent to each other, the intermediate bearing is held, and the primary coolant channel And an intermediate bearing bracket in which a flow path constituting a part is formed.

  Since the primary coolant flow path is formed inside the peripheral wall of the motor frame, piping for circulating the primary coolant between the submerged motor and the heat exchanger is provided around the submerged motor. There is no need to arrange the motor, and the outer diameter of the submerged motor can be reduced over its entire length. In addition, since the primary coolant outlet pipe and the primary coolant inlet pipe arranged between the submerged motor and the heat exchanger are both straight pipes extending along the pump section, the outer diameter of the pump section is also minimized. The Therefore, the submerged motor pump of the present invention can be used by being able to reduce the outer diameter over the entire length direction and through a protective tube having a smaller inner diameter. Furthermore, since the motor frame covers the entire length of the submerged motor, the heat conversion efficiency is high, and the cooling liquid can be guided to the lowermost part of the submerged motor through the primary cooling liquid flow path, thereby enabling efficient cooling.

  The forward-side heat transfer tube and the return-side heat transfer tube arranged in the discharge flow path constituting the heat transfer tube group in the heat exchanger are both straight pipes that extend along the flow direction of the pumped liquid. The water head can be reduced.

  By arranging a plurality of sets of stators and rotors in series in a common motor frame, it is possible to increase the output of the submerged motor without increasing the outer diameter.

  Next, embodiments of the present invention will be described with reference to the accompanying drawings.

(First embodiment)
FIG. 1 to FIG. 2B show a water-sealed high-depth submerged motor pump 1 according to a first embodiment of the present invention. As shown in FIG. 3, the submerged motor pump 1 is disposed in a straight tubular protective tube 3 having openings at both ends extending from the ground surface to an underground tank 2 provided in the ground. A liquid pumping pipe 4 is connected to the upper end of the submerged motor pump 1, and the upper end of the liquid pumping pipe 4 extending to the ground surface through the protective pipe 3 is connected to a downstream pipe 5.

  The submerged motor pump 1 includes a pump unit 11, a submerged motor 12 for driving the pump unit 11, and a heat exchanger 13. The submerged motor 12 is arranged in series below the pump unit 11. Further, the heat exchanger 13 is disposed in series on the upper side of the pump unit 11. The outer diameters of the pump unit 11, the submerged motor 12, and the heat exchanger 13 are set to be smaller than the inner diameter of the protective tube 3, and the submerged motor pump 1 as a whole has an elongated shape. The primary coolant sealed inside the submerged motor 12 circulates between the heat exchanger 13 and is cooled by heat exchange with the secondary coolant that is the pumped liquid of the pump unit 11 in the heat exchanger 13. Is done.

  Next, the pump unit 11 will be described. As most clearly shown in FIG. 2A, the pump unit 11 in this embodiment includes five-stage pumps 16 </ b> A to 16 </ b> E having a common pump shaft 15. Each pump 16 </ b> A to 16 </ b> E includes a pump casing 17, a sliding bearing 18 of the pump shaft 15, and an impeller 19 fixed to the pump shaft 15. The pump casings 17 of the five-stage pumps 16 </ b> A to 16 </ b> E are connected in series so that the suction side is the lower side and the discharge side is the upper side. A connection casing 21 is connected to the suction side of the pump casing 17 of the pump 16A in the first stage (the lowermost side in the drawing), and the connection casing 21 is provided with a suction port 21a. On the other hand, a check valve casing 23 is connected to the discharge side of the pump casing 17 of the pump 16E at the fifth stage (the uppermost side in the drawing) via an intermediate casing 22. In the check valve casing 23, a check valve 24 which is a spring type in this embodiment is accommodated. A discharge pipe 82 constituting a part of the heat exchanger 13 is connected to the check valve casing 23. The upper end side of the discharge pipe 82 is connected to the pumped liquid pipe 4. After the liquid (for example, liquefied natural gas) in the underground tank 2 sucked from the suction port 21a is sequentially pressurized by the five-stage pumps 16A to 16E, the intermediate casing 22, the check valve casing 23, and the discharge It is discharged to the pumped liquid pipe 4 through the pipe 82, and sent to the downstream pipe 5 arranged on the ground surface through the pumped liquid pipe 4.

  Next, the submerged motor 12 will be described with further reference to FIG. As most clearly shown in FIG. 2B, the submerged motor 12 includes a cylindrical motor frame 26 having both upper and lower ends opened. The motor frame 26 covers the entire length of the submerged motor 12, and a motor shaft 28 to which a rotor 27 is fixed is accommodated therein. A stator 29 is fixed to the inner surface of the motor frame 26 so as to face the rotor 27. A stator winding 31 is wound around the stator 29.

  An opening on the upper end side of the motor frame 26 is sealed with an upper end plate 39, and an upper bearing bracket 34 is disposed on the lower side thereof. A seal casing 35 is fixed on the upper end plate 39. The upper end of the motor shaft 28 that passes through the upper bearing bracket 34 and the upper end plate 39 and protrudes into the seal casing 35 is connected to the lower end of the pump shaft 15 by a sleeve coupling 36. Further, the motor shaft 28 is sealed at the seal casing 35. In the present embodiment, the shaft seal device is a tandem type considering the prevention of adhesion of deposits such as calcium carbonate that may be deposited in the liquid in the underground tank 2 and the vertical movement of the motor shaft 28 and the pump shaft 15. The mechanical seal 37 is adopted. Further, the seal casing 35 includes a pressure adjusting device 38.

  On the other hand, the opening on the lower end side of the motor frame 26 is sealed by the lower end plate 41. A lower bearing bracket 44 including a lower part 42 and an upper part 43 is disposed inside the motor frame 26 in the vicinity of the lower end plate 41. A lower part 42 is fixed above the lower end plate 41 with a space therebetween, and an upper part 43 is fixed thereon.

  Here, the bearing structure of the motor shaft 28 will be described. An upper radial bearing 46 and a lower radial bearing 47 made of slide bearings are attached to the upper bearing bracket 34 and the lower bearing bracket 44, respectively. The radial load of the motor shaft 28 is supported by the upper radial bearing 46 and the lower radial bearing 47. A thrust collar 48 is provided in the vicinity of the lower end of the motor shaft 28. The lower part 42 and the upper part 43 of the lower bearing bracket 44 correspond to upper and lower surfaces of the thrust collar 48, respectively. A lower thrust bearing 49 and an upper thrust bearing 50 are attached. The thrust load of the motor shaft 28 is supported by the lower thrust bearing 49 and the upper thrust bearing 50.

  Next, cooling of the submerged motor 12 will be described. The interior of the submerged motor 12, that is, the space sealed by the motor frame 26, the upper end plate 39, the mechanical seal 37, and the lower end plate 41 is filled with the primary coolant. As described above, the primary coolant circulates between the submerged motor 12 and the heat exchanger 13 and is cooled by heat exchange with the pumped liquid in the heat exchanger 13.

  First, the circulation system of the primary coolant will be described. As shown in FIGS. 2B, 4, and 5, a primary coolant channel 26 b is formed in the cylindrical peripheral wall portion 26 a of the motor frame 26. The primary coolant passage 26b is a cylindrical space formed inside the peripheral wall portion 26a, and extends in the length direction of the peripheral wall portion 26a. More specifically, the lower end side of the primary coolant passage 26b is a closed end, and the space (the end plate 41 and the lower bearing bracket) in the motor frame 26 through the primary coolant inlet 26c formed in the peripheral wall portion 26a. 44). On the other hand, a primary coolant inlet pipe 80, which will be described later, is connected to the upper end side of the primary coolant path 26b, and the primary coolant from the heat exchanger 13 is primary as shown by a two-dot chain line L1 in FIG. The coolant flows from the coolant inlet pipe 80 into the primary coolant channel 26b.

  In order to circulate the primary coolant, the thrust collar 48 has a function as an impeller. Referring to FIG. 5, the thrust collar 48 is formed with an axial flow path 48a extending from the lower end and a radial flow path 48b extending radially from the axial flow path 48a. The axial flow path 48 a opens in a space between the end plate 41 and the lower part 42 of the lower bearing bracket 44. On the other hand, the radial flow path 48 b opens in an annular space formed by the outer periphery of the thrust collar 48 and the lower part 42 and the upper part 43 of the lower bearing bracket 44. Further, the upper part 43 of the lower bearing bracket 44 includes an annular space formed by the outer periphery of the thrust collar 48 and the lower part 42 and the upper part 43 of the lower bearing bracket 44, the rotor 27 and the stator 29. A flow path 43a is formed to communicate with the space in which the water is accommodated. Therefore, as indicated by a two-dot chain line L2 in FIG. 5, the primary cooling liquid flowing in from the primary cooling liquid inlet 26c reaches the space in which the rotor 2 and the stator 29 are accommodated via the thrust collar 48.

  On the other hand, as shown most clearly in FIG. 4, on the upper end side of the motor frame 26, the upper end plate 39 is provided with a primary coolant outlet 39a communicating with the inside of the submerged motor 12, and this primary cooling is performed. The liquid outlet 39a is connected to a primary coolant outlet pipe 81 described later. Further, the upper bearing bracket 34 is formed with a flow path 34a for communicating the space in which the rotor 27 and the stator 29 are accommodated with the primary coolant outlet 39a side. Accordingly, as indicated by a two-dot chain line L3 in FIG. 4, the primary coolant flows from the space in which the rotor 27 and the stator 29 are accommodated toward the primary coolant outlet 39a.

  In order to circulate the primary cooling liquid between the submerged motor 12 and the heat exchanger 13, a primary cooling liquid inlet pipe 80 and a primary cooling liquid outlet pipe 81 which are both straight pipes extending along the pump unit 11 are provided. It has been. The primary coolant inlet pipe 80 has a lower end connected to a primary coolant channel 26b formed in the motor casing 26, and an upper end connected to an outlet coolant common pipe 88 of the heat exchanger 13 described later (the outlet of the heat exchanger 13). Side). The primary coolant cooled by the heat exchanger 13 flows through the primary coolant inlet pipe 80 to the primary coolant channel 26b. On the other hand, the primary coolant outlet pipe 81 has a lower end connected to a primary coolant outlet 39a formed on the upper end plate 39, and an upper end side of the inlet coolant common pipe 87 (heat exchanger) of the heat exchanger 13 to be described later. 13 inlet side). The primary coolant flows from the inside of the motor frame 26 to the heat exchanger 13 through the primary coolant outlet pipe 81.

  Next, the heat exchanger 13 will be described. Referring to FIGS. 1, 2 </ b> A, and 3, the heat exchanger 13 has one end connected to the check valve casing 23 (discharge side of the pump unit 11) and the other end connected to the pumping pipe 4. The discharge pipe 82 is provided. In the discharge pipe 82, a discharge flow path 83 in which the pumped liquid discharged from the pump unit 11 flows toward the pumped pipe 4 is formed. A heat transfer tube group 84 through which the primary coolant passes is disposed in the discharge channel 83. The heat transfer tube group 84 includes a plurality of (eight in the present embodiment) forward path heat transfer tubes 85, a plurality of (eight in the present embodiment) return path side heat transfer tubes 86, and an inlet portion coolant common pipe (second tube). A cooling liquid common pipe) 87, an outlet cooling liquid common pipe (third cooling liquid common pipe) 88, and an upper cooling liquid common pipe (first cooling liquid common pipe) 89.

  The forward-side heat transfer tube 85 and the return-side heat transfer tube 86 are straight tubes extending along the flow direction of the pumped liquid, and are disposed along the tube wall of the discharge tube 82.

  The inlet coolant common pipe 87 is disposed along the pipe wall of the discharge pipe 82 on the inlet 83a side of the discharge flow path 83, and is a semicircular closed pipe as shown in FIG. The upper end side of the primary coolant outlet pipe 81 is connected to the bottom wall (wall on the pump part 11 side) of the inlet part coolant common pipe 87. Further, as shown in FIG. 7, the lower end side of the eight forward-side heat transfer tubes 85 is connected to the upper wall (wall on the pumped-up tube 4 side) of the inlet-portion coolant common pipe 87.

  The outlet cooling liquid common pipe 88 is also disposed along the pipe wall of the discharge pipe 82 on the inlet 83a side of the discharge flow path 83, and is a semicircular closed pipe as shown in FIG. The outlet cooling liquid common pipe 88 and the inlet cooling liquid common pipe 87 are disposed at the same position (position in the flow direction of the pumped liquid) in the discharge flow path 83. The upper end side of the primary coolant outlet pipe 81 is connected to the bottom wall of the outlet part coolant common pipe 88. Further, as shown in FIG. 7, the lower end side of the eight return side heat transfer tubes 86 is connected to the upper wall of the outlet portion coolant common pipe 88.

  The upper coolant common pipe 89 is disposed along the pipe wall of the discharge pipe 82 on the outlet 83b side of the discharge flow path 83, and is an annular closed pipe as shown in FIG. To the bottom wall of the upper coolant common pipe 89, the upper ends of the eight forward-side heat transfer tubes 85 and the eight backward-side heat transfer tubes 86 are connected. An air vent pipe 90 extending in the same direction as the discharge pipe 82 is connected to the upper coolant common pipe 89, and is connected to a head tank 91 installed on the ground surface via the air vent pipe 90.

  The path through which the primary coolant flows in the heat exchanger 13 will be described. First, the primary coolant from the submerged motor 12 flows into the inlet coolant common pipe 87 via the primary coolant outlet pipe 81 and cools the inlet. The liquid common pipe 87 flows into the forward path heat transfer pipe 85. The primary coolant flows through the forward-side heat transfer tube 85 to the outlet 83 b side of the discharge channel 83 and flows into the upper coolant common tube 89. Further, the primary cooling liquid flows from the upper cooling liquid common pipe 89 into the return path heat transfer pipe 86, flows toward the inlet side 83 a of the discharge flow path 83, and flows into the outlet portion cooling liquid common pipe 88. When passing through the forward-side heat transfer tube 85 and the backward-side heat transfer tube 86, heat exchange is performed between the primary coolant and the pumped liquid (secondary coolant) flowing through the discharge passage 83, whereby the primary coolant is To be cooled. The primary coolant flows into the primary coolant inlet pipe 80 from the outlet coolant common pipe 88 and returns to the submerged pump 12 through the primary coolant inlet pipe 80.

  Referring to FIGS. 2A, 4, and 5, when the pumps 16 </ b> A to 16 </ b> E of the pump unit 11 are driven by the submerged motor 12, the primary cooling liquid is changed to the two-dot chain lines L <b> 1 to L <b> 4 by the impeller effect of the thrust collar 48. It circulates in the route shown by. Specifically, the primary coolant pressurized by the impeller effect of the thrust collar 48 passes through the lower bearing bracket 44, the lower radial bearing 47, the stator winding 31, and the upper bearing radial bearing bracket 34. It flows into the primary coolant outlet pipe 81 from the outlet 39a (see the two-dot chain line L2 in FIG. 5 and the two-dot chain line L3 in FIG. 4). Next, the primary coolant flows into the heat exchanger 13 through the primary coolant outlet pipe 81, and flows into the primary coolant inlet pipe 80 through the heat exchanger 13 (see the two-dot chain line L4 in FIG. 2A). . As described above, in the heat exchanger 13, the primary coolant is the inlet-portion coolant common tube 87, the forward-side heat transfer tube 85, the upper coolant-common tube 89, the return-side heat transfer tube 86, and the outlet-portion coolant common tube. 88, and is cooled by heat exchange with the pumped liquid in the forward-side heat transfer tube 85 and the backward-side heat transfer tube 86. Further, the primary coolant flows from the primary coolant inlet pipe 80 into the primary coolant channel 26b formed in the peripheral wall portion 26a of the motor frame 26, and flows into the motor frame 26 from the primary coolant inlet 26c. Returning to the collar 48 (see the two-dot chain line L1 in FIG. 4 and the two-dot chain line L2 in FIG. 5).

  As described above, in the submerged motor pump 1 of the present embodiment, the primary coolant flow path 26b is formed inside the peripheral wall portion 26a of the motor frame 26, so that the primary coolant is heat exchanged with the submerged motor 12. It is not necessary to arrange a pipe for circulating the primary coolant between the vessels 13 around the submerged motor 12, and the outer diameter of the submerged motor 12 can be reduced over its entire length. In addition, since the primary coolant outlet pipe 81 and the primary coolant inlet pipe 80 disposed between the submerged motor 12 and the heat exchanger 13 are both straight pipes extending along the pump section 11, the outside of the pump section. The diameter is also minimized. Therefore, the outer diameter can be reduced over the entire length of the submerged motor pump 1, and it can be used by being inserted into a protective tube having a smaller inner diameter. Further, since the motor frame 26 covers the entire length of the submerged motor, the heat conversion efficiency is high, and the primary cooling liquid channel 26b guides the primary cooling liquid to the lowermost part of the submerged motor 11, thereby enabling efficient cooling. is there. Furthermore, since both the forward-side heat transfer pipe 85 and the backward-side heat transfer pipe 86 arranged in the discharge flow path 83 provided in the heat exchanger 13 are straight pipes that extend along the flow direction of the pumped liquid, Loss head can be reduced.

  Next, a method for supplying power to the submerged motor 12 will be described. As shown in FIG. 1, in order to supply power to the submerged motor 12 from the power cable 64, a plurality of watertight connectors 61 (three in this embodiment as shown in FIG. 8) are connected to the submerged motor pump 1. Provided. This connector 61 is provided on a receptacle 62 electrically connected to the stator winding 31 of the submerged motor 12 and a power cable 64 extending through a protective tube (see FIG. 3) to the power supply on the ground side or to the power system. And a plug 63 into which the receptacle 62 is fitted. Since the power cable 64 can be separated from the submerged motor pump 1 by this connector, handling and transportability are improved.

  Referring to FIG. 9, the receptacle 62 (submerged motor 12 side) of the connector 61 includes a male contact 67 and a pin insulator 68 in the shell 66. On the other hand, the plug 63 of the connector 61 (power cable 64 side) includes a female contact 71 and a socket insulator 72 electrically connected to the power cable 64 in the end bells 69 and 70. The female connector 61 and the socket insulator 72 protrude from the end of the end bell 69. Further, the end bell 69 is provided with a coupling nut 73 at the tip. When the plug 63 is inserted into the receptacle 62, the male contact 67 is inserted into the female contact 71, the submerged motor 12 side and the power cable 64 side are electrically connected, and the pin insulator 68 is inserted into the socket insulator 72. . After the coupling of the receptacle 62 and the plug 63 is completed, the coupling nut 73 is screwed into the shell 68 of the receptacle 62, and the plug 63 is filled with resin.

  The power cable 64 is provided with a corrugated metal sheath 76 made of stainless steel or the like in consideration of permeability, water immersion, and corrosivity. By adopting this corrugated metal sheath 76, it is possible to ensure good flexibility while preventing intrusion of liquefied natural gas, seawater or the like into the power cable. Further, by providing a special polyethylene layer 77 outside the power cable 64, it can be directly installed in liquefied natural gas, seawater, or the like.

(Second Embodiment)
FIGS. 10 to 12 show a water-sealed high-depth submerged motor pump 1 according to a second embodiment of the present invention.

  In the present embodiment, the submerged motor 12 includes two sets of stators 29A and 29B and rotors 27A and 27B arranged in series in a common motor frame 26. Further, in the motor frame 26, an intermediate bearing 101 that supports the motor shaft 28 between a pair of stators 29A and 29B and rotors 27A and 27B that are adjacent to each other, and an intermediate bearing bracket 102 that holds the intermediate bearing 101. Is arranged. As shown most clearly in FIG. 12, the intermediate bearing bracket 102 is formed with a flow path 102a that constitutes a part of the primary coolant flow path 26b. By arranging two sets of stators 29A and 29B and rotors 27A and 27B in series in a common motor frame 26, the output of the submerged motor 12 can be increased without increasing the outer diameter. Three or more sets of stators and rotors may be arranged in the motor frame 26.

  Since other configurations and operations of the second embodiment are the same as those of the first embodiment, the same elements are denoted by the same reference numerals and description thereof is omitted.

The longitudinal cross-sectional view which shows the submersible motor pump which concerns on 1st Embodiment of this invention. The longitudinal cross-sectional view which shows the upper part of the submerged motor pump which concerns on 1st Embodiment of this invention. The longitudinal cross-sectional view which shows the lower part of the submersible motor pump which concerns on 1st Embodiment of this invention. The longitudinal cross-sectional view which shows the installation state of the submerged motor pump which concerns on 1st Embodiment of this invention. The elements on larger scale of the part IV of FIG. The elements on larger scale of the part V of FIG. Sectional drawing in the VI-VI line of FIG. Sectional drawing in the VII-VII line of FIG. Sectional drawing in the VIII-VIII line of FIG. The partial cross section front view which shows a connector. The longitudinal cross-sectional view which shows the submersible motor pump which concerns on 2nd Embodiment of this invention. The longitudinal cross-sectional view which shows the upper part of the submersible motor pump which concerns on 2nd Embodiment of this invention. The longitudinal cross-sectional view which shows the lower part of the submersible motor pump which concerns on 2nd Embodiment of this invention. FIG. 11B is a partially enlarged view of a portion XII in FIG. 11B.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Submerged motor pump 2 Underground tank 3 Protective pipe 4 Lifting pipe 5 Piping 11 Pump part 12 Submerged motor 13 Heat exchanger 15 Pump shaft 16A-16E Pump 17 Pump casing 18 Slide bearing 19 Impeller 21 Connection casing 21a Inlet 22 intermediate casing 23 check valve casing 24 check valve 26 motor frame 26a peripheral wall portion 26b primary coolant flow path 26c primary coolant inlet 27, 27A, 28b rotor 28 motor shaft 29, 29A, 29B stator 31 stator winding Line 34 Upper bearing bracket 34a Flow path 35 Seal casing 36 Sleeve coupling 37 Mechanical seal 38 Pressure adjustment device 39 Upper end plate 39a Primary coolant outlet 41 Lower end plate 42 Lower part 43 Upper part 43a Flow path 44 Lower part Bearing bra 46 Upper radial bearing 47 Lower radial bearing 48 Thrust collar 48a Axial flow path 48b Radial flow path 49 Lower thrust bearing 50 Upper thrust bearing 61 Connector 62 Receptacle 63 Plug 64 Power cable 66 Shell 67 Male contact 68 Pin insulator 69 , 70 End bell 71 Female contact 72 Socket insulator 73 Coupling nut 76 Corrugated metal exterior 77 Special polyethylene layer 80 Primary coolant inlet pipe 81 Primary coolant outlet pipe 82 Discharge pipe 83 Discharge flow path 83a Inlet side 83b Outlet 84 Heat transfer pipe Group 85 Outgoing side heat transfer tube 86 Return side heat transfer tube 87 Inlet cooling liquid common pipe 88 Outlet cooling liquid common pipe 89 Upper cooling liquid common pipe 90 Air vent pipe 91 Head tank 101 Intermediate bearing 102 Intermediate bearing bracket 102a channel

Claims (6)

A pump unit, a submerged motor for driving the pump unit arranged in series with the pump unit, a primary coolant sealed in a motor frame of the submerged motor, and a pumped liquid of the pump unit In a submerged motor pump comprising a heat exchanger for performing heat exchange with a secondary coolant,
The heat exchanger has one end connected to the discharge side of the pump part and the other end connected to a pumping pipe, and a straight pipe discharge pipe including a discharge channel through which the pumped liquid discharged by the pump part passes, A heat transfer tube group piped in the discharge flow path and through which the primary coolant passes,
The motor frame covers the entire length of the submerged motor,
A straight tubular primary coolant outlet pipe extending along the pump portion, connecting a primary coolant outlet from the motor frame and an inlet side of the heat transfer tube group;
A primary coolant passage formed inside the peripheral wall portion of the motor frame so as to extend in the length direction of the peripheral wall portion, and having one end connected to a primary coolant inlet into the motor frame;
A submerged motor pump, comprising: a straight tubular primary coolant inlet pipe extending along the pump portion that connects an outlet side of the heat transfer tube group and the other end of the primary coolant flow path.   Rotating in conjunction with the drive shaft of the submerged motor to pressurize the primary coolant, and from the motor frame, the primary coolant outlet, the primary coolant outlet tube, the heat transfer tube group, the primary coolant 2. The liquid according to claim 1, further comprising: a rotating body that circulates the primary cooling water through an inlet pipe, the primary cooling liquid path, and a flow path that returns to the motor frame through the primary cooling liquid inlet. Medium motor pump. The heat transfer tube group is:
A plurality of forward-side heat transfer tubes arranged in the discharge flow channel and extending in the flow direction of the pumped liquid and having an end on the liquid pump side connected to the primary coolant outlet tube When,
A plurality of return-side heat transfer tubes arranged in the discharge flow channel and extending in the flow direction of the pumped liquid, and having an end on the submerged pump side connected to the primary coolant inlet tube When,
The liquid according to claim 2, further comprising: a first coolant common pipe to which ends of the forward path side heat transfer pipe and the backward path side heat transfer pipe opposite to the liquid pump are connected. Medium motor pump. The heat transfer tube group is:
A second coolant common pipe in which the liquid pump side end of the plurality of forward path heat transfer tubes and the primary coolant outlet pipe are connected;
4. The liquid according to claim 3, further comprising: a third coolant common pipe in which ends of the plurality of return-side heat transfer tubes on the submerged pump side and the primary coolant inlet pipe are connected. Medium motor pump. The submerged motor is
The submersible motor pump according to any one of claims 1 to 4, further comprising a plurality of sets of stators and rotors arranged in series in the common motor frame. An intermediate bearing disposed within the motor frame and supporting the drive shaft between the stator and rotor pairs adjacent to each other;
The submerged motor pump according to claim 5, further comprising: an intermediate bearing bracket that holds the intermediate bearing and has a flow path that forms a part of the primary coolant flow path.

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