TW201533411A - Refrigerant pump and binary power generation system using same - Google Patents

Abstract

The invention provides a small refrigerant pump which can improve motor efficiency and can feed a liquefied refrigerant stably, and a binary power generation system using the refrigerant pump. A refrigerant pump 6 includes a pump part 40 for pressurizing the liquefied refrigerant for feeding, a motor part 31 for driving the pump part, a driving shaft 30 for transmitting the rotation driving force produced by the motor part to the pump part, and a casing 20 which has a pump room 60 and a motor room 70 in which the pump part and the motor part are hermetically housed, respectively. The pump part is an internal gear pump formed at the end of the driving shaft, the driving shaft has communicating holes 50, 51 for communicating the pump room and the motor room, and the casing has a discharge passage 54 which connects the motor room to a low-pressure line 5d of binary power generation system 1.

Description

Refrigerant pumping and dual-cycle power generation system using the refrigerant pump

The present invention relates to a refrigerant pump that pressurizes a refrigerant (working medium) liquefied by a condenser and sends it to an evaporator, and a dual-cycle power generation system that uses the refrigerant pump.

In recent years, from the viewpoint of energy conservation, it recycles low-temperature waste heat and other low-level heat energy discharged from various equipments, devices, and machines such as factories, ships, vehicles, and work machines, and uses recycled waste heat energy. The demand for power generation systems is getting higher and higher.

A waste heat power generation system, for example, an evaporator for evaporating a refrigerant (working medium), an expander for expanding a refrigerant vapor, a condenser for condensing refrigerant vapor, and a refrigerant for circulating a refrigerant. In a closed circuit, a two-cycle power generation system in which a refrigerant cycle is performed to constitute a thermal cycle and a generator is driven by an expander is well known.

In such a dual-cycle power generation system, in order to circulate the refrigerant in a closed circuit, it is necessary to provide a refrigerant pump in a closed circuit, and the refrigerant pump can use various types of materials, for example, a pump using a canned motor.

Pumping of the above-described canned motor, for example, as disclosed in Patent Document 1 The things are well known to everyone. The canned motor is pumped, the impeller is housed in the pump casing, and the rotor of the motor that drives the pump is housed in a pressure liquid chamber formed on the inner circumference side of the can of the stator, and the pressure liquid chamber is filled with the pump Pu treatment liquid (working medium). From the discharge side of the pump, a part of the pump treatment liquid is guided into the pressure liquid chamber, and the pump treatment liquid is used to perform lubrication and cooling of the rotor and the sliding bearing in the pressure liquid chamber. A through hole is formed in the shaft of the motor that drives the impeller, and the pumping treatment liquid passes through the through hole, returns from the pressure liquid chamber to the suction side of the pump, and is sent to the pump discharge side together with the new pump treatment liquid. .

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2007-127135

In the canned motor pump disclosed in Patent Document 1, there is a partition wall called a can between the rotor and the stator, and the distance between the rotor and the stator becomes long because of the can between the rotor and the stator. Motor efficiency is degraded. In order to increase the efficiency of the motor and to make the thickness of the can thin, there are the following problems. In other words, the pressure liquid chamber on the rotor side of the can of the stator becomes a high pressure due to the pumping of the pumping treatment liquid, and on the opposite side of the tank in which the stator is interposed in the pressure liquid chamber. Atmospheric pressure. Therefore, since a large pressure difference is generated between the cans of the stator, it is difficult to make the thickness of the cans of the stator thin, and it is difficult to shorten the distance between the rotor and the stator to improve the efficiency of the motor. question. Further, in the configuration shown in Patent Document 1, since the rotor and the stator are covered by the can, the cooling effect on the rotor and the stator by the pumping treatment liquid is weak, and there is a problem that the motor efficiency is poor.

Further, since the canned motor pump of Patent Document 1 is a centrifugal pump using an impeller, there is also a problem that the pump portion is large and the pump is difficult to be miniaturized. Further, it is difficult to make the can thin, and it is necessary to use a space for providing the can, and thus there is also a problem that the motor portion becomes large.

Further, the configuration in which the pumping treatment liquid is directly returned from the pressure liquid chamber to the suction side in the pump through the through hole has the following problems. That is, when the pumping treatment liquid is a low-boiling refrigerant, the motor is cooled by the pumping treatment liquid, and as a result, the pumping treatment liquid is heated, and the pumping treatment liquid heated is likely to generate air pockets. Therefore, there is a problem in that it is difficult to pump the pumping liquid or the like due to the generation of air bubbles in the pump.

Therefore, the technical problem to be solved by the present invention is to provide a small-sized refrigerant pump that can improve the efficiency of the motor and reliably deliver the liquefied refrigerant, and a dual-cycle power generation system that uses the refrigerant pump.

In order to solve the above technical problems, according to the present invention, the following refrigerant pumping is provided.

That is, the refrigerant pump of the present invention is a refrigerant pump used in a two-cycle power generation system, characterized in that the refrigerant pump has a pumping portion for boosting and delivering the liquefied refrigerant. a motor portion for driving the pump portion; a drive shaft for driving a rotational driving force generated by the motor portion And a housing having a pump chamber and a motor chamber that respectively accommodate the pump portion and the motor portion in a sealed state; and the pump portion is disposed at an end of the drive shaft An internal gear pump, the drive shaft has a communication hole for connecting the pump chamber and the motor chamber, and the housing has a low-pressure line for connecting the motor chamber to the dual-cycle power generation system. The discharge flow path.

In the refrigerant pump of the present invention, the pumping portion is miniaturized by using a pumping portion as an internal gear pump provided at the end of the drive shaft. Since the pump chamber and the motor chamber of the casing are respectively in a sealed state, leakage of the refrigerant is prevented, and it is not necessary to use a partition wall such as a tank that separates the rotor of the motor from the stator. Thereby, the distance between the rotor and the stator can be shortened, and the rotor and the stator can be directly cooled, so that the motor efficiency can be improved and the motor portion can be miniaturized. By providing the communication hole in the drive shaft, the pump chamber and the motor chamber can be connected without using an external pipe. By the housing having a discharge flow path for connecting the motor chamber to the low-pressure line of the dual-cycle power generation system, the refrigerant can be supplied to the motor chamber from the pump chamber through the communication hole provided in the drive shaft without using other pumps. Therefore, the present invention can achieve the following effects, and can provide not only a small-sized refrigerant pump in which motor efficiency is improved, but also a two-cycle power generation system that improves the overall efficiency by pumping the refrigerant.

1‧‧‧Double-cycle power generation system

2‧‧‧Power generator

3‧‧‧Expander

4‧‧‧Generator

5‧‧‧Refrigerant circulation pipeline

5a‧‧‧Pump inlet side line

5b‧‧‧Pump exit side pipeline

5c‧‧‧Expander inlet side line

5d‧‧‧Expander outlet side line (low pressure line)

5e‧‧‧Return pipeline

6‧‧‧Refrigerated pump

7‧‧‧Evaporator

8‧‧‧Condenser

17‧‧‧ Warm fluid flow path

18‧‧‧Cooling water flow path

20‧‧‧shell

21‧‧‧Motor housing

22‧‧‧ pump housing

23‧‧‧End cover

25‧‧‧ bearing

26‧‧‧ Bearing

27A‧‧‧ bearing support

27B‧‧‧ bearing support

27C‧‧‧ bearing support

28‧‧‧ partition wall

29‧‧‧ partition wall

30‧‧‧Drive shaft

31‧‧‧Motor Department

32‧‧‧Rotor

33‧‧‧ Stator

35‧‧‧ gap

40‧‧‧Internal gear pump (pump section)

41‧‧‧ inner rotor

42‧‧‧Outer rotor

43‧‧‧Inhalation test

44‧‧‧ spit out

50‧‧‧Axis direction communication hole (connection hole)

51‧‧‧Pathway communication hole (communication hole)

52‧‧‧ oil supply flow path

53‧‧‧ Oil supply flow path

54‧‧‧Draining flow path

60‧‧‧ pumping room

61‧‧‧ bearing room

62‧‧‧1st motor room (pump side space of motor room)

63‧‧‧2nd motor room

64‧‧‧3rd motor room (the opposite side of the pumping of the motor room)

65‧‧‧ bearing room

68‧‧‧1st space

69‧‧‧Second space

70‧‧‧Motor room

Rotating center of the inner rotor of O1‧‧

O2‧‧‧The center of rotation of the outer rotor

Fig. 1 is a schematic view showing a two-cycle power generation system according to an embodiment of the present invention.

Fig. 2 is a longitudinal sectional view showing a refrigerant pump of an embodiment used in the two-cycle power generation system shown in Fig. 1.

Fig. 3 is a vertical sectional view of the internal gear pump of the refrigerant pump shown in Fig. 2;

Fig. 4 is a longitudinal sectional view showing a refrigerant pump of a modification.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. Further, in the present specification, the axial direction of the drive shaft 30 relatively refers to the side of the internal gear pump 40 as the pump side, and the motor side 31 side or the opposite side of the internal gear pump 40 is referred to as the motor side. Or pump the opposite side.

Fig. 1 is a schematic view showing the configuration of a two-cycle power generation system 1 according to an embodiment. The two-cycle power generation system 1 is a refrigerant that recovers energy from a low-temperature waste heat by using a refrigerant having a boiling point lower than that of water, and a refrigerant having a lower boiling point than water, for example, a chlorofluorocarbon substitute such as R245fa. The dual cycle power generation system 1 is provided with a refrigerant 7, a power generation device 2, a condenser 8, and a refrigerant pump 6, in a refrigerant circulation line 5 in which a refrigerant circulates.

The refrigerant liquefied by the condenser 8 is sent to the refrigerant pump 6 through the pump inlet side line 5a. Refrigerant pump 6, used to be condensed The refrigerant liquefied by the device 8 is boosted to a specific pressure and sent to the evaporator 7. The details of the refrigerant pump 6 will be described later.

The evaporator 7 generates a refrigerant vapor by a liquid refrigerant. The evaporator 7 uses waste heat to evaporate the refrigerant which is pumped by the refrigerant pump 6 through the pump outlet side line 5b of the refrigerant circulation line 5. The evaporator 7 has a warm fluid flow path 17 through which warm liquid fluid heated by waste heat is circulated. The warm fluid may be a fluid having a temperature higher than a boiling point of the refrigerant, or may be heated by the fluid, as long as it is a warm water discharged from a factory or the like, heated air, steam discharged, or warm water flowing from the ground. Intermediate thermal media. The evaporator 7 exchanges heat between the warm fluid and the refrigerant to evaporate the liquid refrigerant. The refrigerant vapor generated by the evaporator 7 is sent to the expander 3 of the power generating device 2 through the expander inlet side line 5c.

The power generation device 2 is steamed by the refrigerant supplied from the evaporator 7. Gas to generate electricity. The power generating device 2 includes a spiral expander 3 and a generator 4, and the screw expander 3 is rotationally driven by the expansion force of the refrigerant vapor, that is, by the pressure difference before and after the expansion, and the generator 4 follows It is rotated to perform power generation. The refrigerant vapor used for power generation in the power generation device 2 is sent to the condenser 8 through the expander outlet side line 5d.

The condenser 8 feeds the refrigerant vapor supplied by the power generating device 2 Cooling is carried out to liquefy (condense) the refrigerant vapor. The condenser 8 performs heat exchange between the low-temperature cooling water flowing through the cooling water flow path 18 and the refrigerant to cool and liquefy (condense) the refrigerant vapor. The liquid refrigerant discharged by the condenser 8 is pumped by a refrigerant disposed between the condenser 8 and the evaporator 7. 6. Pressing from the condenser 8 toward the evaporator 7. The liquid refrigerant that is sent to the evaporator 7 is again evaporated in the evaporator 7.

The dual-cycle power generation system 1 of the above embodiment, the refrigerant system is The super refrigerant circulation line 5 is supplied from the evaporator 7 to the power generating unit 2, and is supplied from the power generating unit 2 to the condenser 8, and thereafter, passes through the refrigerant pump 6, and returns from the condenser 8 to the evaporator 7, and It constitutes the circulation path of the refrigerant. In the case of the double-cycle power generation system 1, the refrigerant having a lower boiling point than the water is circulated in the circulation circuit, and the low-temperature waste heat discharged from various equipments such as factories is used to generate electric energy, and two kinds of evaporation cycles and condensation cycles of the refrigerant are used. Thermal cycling to generate electricity.

Next, referring to Figures 2 and 3, for an implementation The refrigerant pump 6 of the type is described in detail. Fig. 2 is a longitudinal sectional view of the refrigerant pump 6, and Fig. 3 is a vertical sectional view of the internal gear pump 40 of the refrigerant pump 6. In the present embodiment, a trochoid pump (TROCHOID (registered trademark)) is used as the internal gear pump 40.

Refrigerant pump 6 is equipped with: after inhaling liquid refrigerant, spit An internal gear pump (pumping portion) 40 through which the pressurized refrigerant is pressurized; a motor portion 31 for driving the internal gear pump 40; and a housing for housing the internal gear pump 40 and the motor portion 31 in a sealed state 20. The internal gear pump 40 is disposed at the end of the pump shaft side of the drive shaft 30.

The casing 20 of the refrigerant pump 6 is: substantially cylindrical The motor housing 21; is substantially a bottomed cylindrical pump housing 22; and an end cap 23; Next, the pump casing 22 is attached to the side of the pump casing side of the motor casing 21 in a sealed state, and the end cover 23 is attached in a sealed state. The side of the motor housing 21 that is pumped on the opposite side. The motor unit 31 is housed in a sealed state by a motor chamber 70 in an internal space formed by the motor housing 21 and the end cover 23. In the motor chamber 70, a first motor chamber (pump side space) 62 closer to the pump side than the motor portion 31, a second motor chamber 63 corresponding to the motor portion 31, and a closer to the motor portion 31 are formed. The third motor chamber (the opposite side of the pump) 64 on the opposite side of the pump. The pumping chamber 60 in the internal space surrounded by the pump casing 22 and the partition wall 28 houses the internal gear pump 40 in a sealed state. The pumping chamber 60 of the pump housing 22 is composed of: a first space 68 for accommodating the large diameter of the internal gear pump 40; and a small diameter for accommodating the shaft end of the pump side of the drive shaft 30 The second space 69 is formed by the two-stage recess formed. The motor housing 21 and the pump housing 22 are partitioned by a partition wall 28 that is embedded in the pump-side end portion of the motor housing 21. In the partition wall 28, a shaft insertion hole is formed, and the shaft insertion hole is sized to form an opening in such a manner that the pump side portion of the drive shaft 30 is inserted, and is a ratio of the internal gear pump 40. The outer diameter of the outer gear of the inner rotor 41 is small.

As shown in Figure 3, the internal gear pump 40 has a pair The inner side of the gear outer rotor 42 is provided with a structure having an inner rotor 41 having a smaller number of teeth than the inner gear. The meshing gap is formed by the meshing of the outer gear of the inner rotor 41 with the inner gear of the outer rotor 42. The outer peripheral surface of the outer rotor 42 is rotatable under the guidance of the cylindrical inner peripheral surface of the pump chamber 60. The insertion hole of the inner rotor 41 is inserted into the shaft end portion of the pump shaft side of the drive shaft 30, and the shaft end portion is fixed to the insertion hole so as to be in a swing stop state by the key member. According to this configuration, the inner rotor can be directly 41 is mounted on the drive shaft 30 to reduce the number of parts, and can realize the miniaturization of the structure of the motor portion 31. Simplified.

The pump housing 22 is configured to face the first space 68 The end surface of the side surface of the pump chamber 60 formed on the face is formed with a suction port 43 and a discharge port 44 having a shape indicated by a hatched portion in Fig. 3 . The suction port 43 and the discharge port 44 have flow paths leading to the outside of the pump chamber, respectively. As shown in Fig. 2, the suction port 43 is connected to the pump inlet side line 5a through the flow path 43, and the refrigerant liquefied by the condenser 8 is introduced into the pump. When the spout 44 is discharged, the flow path 44 is communicated to the pump outlet side line 5b, and the pressurized liquid refrigerant is sent to the evaporator 7.

In the configuration of the internal gear pump 40, the rotation of the inner rotor 41 The center O1 and the center of rotation O2 of the outer rotor 42 are eccentric, and the number of teeth between the inner rotor 41 and the outer rotor 42 is different. With this configuration, when the inner rotor 41 is rotationally driven, the outer rotor 42 rotates, and depending on the rotational positions of the inner rotor 41 and the outer rotor 42, the volume at which the meshing gap occurs increases or decreases. The liquid refrigerant is sucked from the suction port 43 where the volume of the meshing gap changes. The liquid refrigerant sucked in is caught in the meshing gap, and is rotated by the rotation of the inner rotor 41 and the outer rotor 42 to reduce the volume of the meshing gap. Since the volume of the meshing gap becomes smaller as the inner rotor 41 and the outer rotor 42 rotate, the liquid refrigerant enclosed in the meshing gap is boosted. Next, the liquid refrigerant that has been pressurized is discharged from the discharge port 44. The liquid refrigerant pressurized by the internal gear pump 40 is sent to the evaporator 7 through the pump outlet line 5b.

Go back to Figure 2 for the rotary drive of the internal gear pump The motor unit 31 of 40 will be described.

Transmitting the rotational driving force generated by the motor unit 31 to the inscribed The drive shaft 30 of the inner rotor 41 of the gear pump 40 is supported by the bearings 25, 26 in a freely rotatable manner. The bearing 25 on the pump side is inserted into a bearing chamber 61 formed on the pump side of the motor housing 21. The outer wheel train is fixed by a bearing support body 27A (for example, a C-type fixing ring for holes defined by JIS B2804), and the inner wheel train is fixed to the bearing support body 27B (for example, a C-type fixing ring for a shaft defined by JIS B2804). Drive shaft 30. The bearing 26 on the opposite side of the pump is inserted into the bearing chamber 65 on the opposite side of the pumping of the end cap 23. The inner wheel train is fixed by a bearing support body 27C (for example, a bearing nut specified in JIS B1554) mounted on the motor end of the drive shaft 30. The drive shaft 30 supported by the bearing 25 on the pump side extends through the bearing 25 and the partition wall 28 toward the side of the pump housing 22.

In the first motor chamber 62 and the second horse by the motor housing 21 The motor unit 31 is disposed in the motor chamber 70 formed by the chamber 63 and the third motor chamber 64 of the end cover 23. The motor unit 31 includes a stator 33 that is fixed to the inner circumferential surface of the second motor chamber 63 of the motor casing 21, and a rotor 32 that is disposed at intervals in the radial direction of the stator 33. The rotor 32 is fixed to the drive shaft 30. The rotor 32 is composed of a permanent magnet, and the stator 33 is composed of a coil around which a metal wire is wound. A can exists in the canned motor between the stator 33 and the rotor 32. Therefore, the stator 33 is disposed in the radial direction at intervals from the outer peripheral surface of the rotor 32 with a slight gap 35. Therefore, since the interval between the rotor 32 and the stator 33 is shortened The distance can improve the efficiency of the motor. Further, the first motor chamber 62 and the third motor chamber 64, which are separated by the motor portion 31, communicate with each other through the gap 35 formed in the motor portion 31, and the liquid refrigerant flowing into the first motor chamber 62 can pass through the gap 35. It flows into the third motor chamber 64.

The drive shaft 30 may also be the rotor 32 of the motor portion 31. It is fixed to the intermediate portion of the integrally formed shaft, and the inner rotor 41 of the internal gear pump 40 is fixed to one end side thereof. Alternatively, the drive shaft 30 may be configured by a single shaft that is coupled to the first shaft of the inner rotor 41 to which the internal gear pump 40 is fixed, and two individual shafts to which the second shaft of the rotor 32 of the motor unit 31 is fixed. .

The pump side portion of the drive shaft 30 is internally formed The axial direction communication hole 50 (communication hole) extending in the axial direction and the radial direction communication hole 51 (communication hole) extending in the direction in which the axes intersect perpendicularly (diameter direction). The axial direction communication hole 50 is formed by the shaft end portion of the pump side and is held by the bearing 25 and the rotor 32 and extends to a region facing the first motor chamber 62, and has a shaft end portion formed on the pump side. Opening. In the pump chamber 60, between the end faces of the pump shafts formed in the pump casing 22 and the end faces of the inner rotors 41 of the inward gear pump 40, the suction ports 43 and the discharge ports 44 are not formed. The portion (set in the range indicated by the oblique line in Fig. 3) necessarily forms a minute gap. Therefore, in the gap between the pump chambers 60, it is possible to provide a flow path through which the leakage liquid refrigerant flows in a small amount with respect to the discharge amount. As shown in FIG. 3, the opening portion on the pump side of the axial direction communication hole 50 is opened at a position between the suction port 43 and the discharge port 44. In other words, the opening portion on the pump side is in the pump chamber 60 of the internal gear pump 40, The opening is at a position that is an intermediate pressure between the suction pressure and the discharge pressure. The radial direction communication hole 51 communicates with the axial direction communication hole 50 and extends to the outer circumferential surface of the drive shaft 30, and has an opening formed in the outer circumferential surface of the drive shaft 30. Therefore, the pump chamber 60 and the first motor chamber 62 communicate with each other through the axial direction communication hole 50 and the radial direction communication hole 51 formed in the drive shaft 30. As described above, the pump chamber 60 and the third motor chamber 64 communicate with each other through the axial direction communication hole 50, the radial direction communication hole 51, the first motor chamber 62, and the gap 35. Therefore, a part of the liquid refrigerant introduced into the pump chamber 60 can flow into the first motor chamber 62 after passing through the axial direction communication hole 50 and the radial direction communication hole 51 of the drive shaft 30.

Pump chamber 60, on the pump side end face of the partition wall 28, and A slight gap is inevitably formed between the motor-side end faces of the inner rotor 41 of the internal gear pump 40. Therefore, the gap is a flow path through which a liquid refrigerant that leaks a small amount with respect to the discharge amount can be supplied. Therefore, a part of the liquid refrigerant introduced into the pump chamber 60 passes through the gap and the shaft insertion hole of the partition wall 28, and then can flow into the first motor chamber 62 through the bearing 25.

On the upper side of the pump side of the motor housing 21, a pair of bearings are provided The oil supply passage 52 for supplying the lubricating oil to the oil is provided on the side opposite to the pumping side of the end cover 23, and the oil supply passage 53 for supplying oil to the bearing 26 is provided. Further, a discharge passage 54 for discharging the liquid refrigerant after cooling the motor portion 31 is provided at a lower portion of the pump cover side of the end cover 23.

Discharge flow path 54, as shown in Figure 1, via a return line 5e, the low pressure line connected to the double cycle power generation system 1, preferably connected to the front portion of the agglomerator 8 of the expander outlet side line 5d. Therefore, the flow The refrigerant and the lubricating oil entering the motor chamber 70 can flow to the low-pressure line of the double-cycle power generation system 1 through which the refrigerant having a lower pressure than the refrigerant flowing into the motor chamber 70 flows.

When lubricating oil is supplied to the bearings 25 and 26, the lubricating oil The liquid refrigerant discharged from the cooling motor unit 31 is discharged from the discharge flow path 54 and then flows to the refrigerant circulation line 5 of the dual cycle power generation system 1. However, in the process of generating the refrigerant vapor from the liquid refrigerant by the evaporator 7, most of the lubricating oil does not become vapor. And, in order to separate more reliably. The lubricating oil contained in the refrigerant vapor is removed. For example, an oil separator (not shown) may be disposed directly in front of or behind the expander 3.

The dual-cycle power generation system 1 and the refrigerant pump configured as above The refrigerant 6 liquefied by the condenser 8 is supplied to the internal gear pump 40 housed in the pump chamber 60 through the suction port 43. The liquid refrigerant is boosted by the internal gear pump 40. Most of the liquid refrigerant is discharged through the discharge port 44 and sent to the evaporator 7. After the liquid refrigerant sent to the evaporator 7 is formed into a refrigerant vapor by the evaporator 7, the refrigerant vapor is supplied to the power generator 2, and the refrigerant vapor is used to generate electricity. The refrigerant vapor used by the power generator 2 is supplied to the condenser 8 to be liquefied. Therefore, the dual-cycle power generation system 1 performs power generation by circulating the refrigerant pump 6 in the refrigerant circulation line 5 by a large part of the refrigerant.

On the other hand, one part of the refrigerant is used for the cooling of the motor unit 31 and the lubrication of the bearings 25 and 26 in the refrigerant pump 6.

In the refrigerant pump 6, a part of the liquid refrigerant introduced into the pumping chamber 60 is formed by passing through the partition wall 28 and the internal gear pump 40. The gap and the shaft of the partition wall 28 are inserted into the through hole, and then flow into the first motor chamber 62 through the bearing 25. Next, one of the liquid refrigerant flows into the first motor chamber 62 after passing through the axial direction communication hole 50 and the radial direction communication hole 51 of the drive shaft 30. At this time, the liquid refrigerant also passes through the bearing 26 when passing through the bearing 25, and the bearings 25 and 26 are lubricated while passing through the bearings 25 and 26. In particular, when lubricating the lubricating oil to the bearings 25 and 26, the lubricating oil contained in the liquid refrigerant effectively lubricates the bearings 25 and 26.

In the motor chamber 70, the first motor chamber that communicates to the pump chamber 60 62 is at a high pressure, and is partitioned by the motor portion 31 and the gap 35, and the third motor chamber 64 that is connected to the expander outlet side line 5d of the low pressure line is at a low pressure. Therefore, a pressure difference is formed between the first motor chamber 62 and the third motor chamber 64. The liquid refrigerant that has flowed into the first motor chamber 62 by the pressure difference can flow into the third motor chamber 64 through the gap 35 and be discharged from the discharge flow path 54. The liquid refrigerant directly cools the rotor 32 and the stator 33 by contacting the surfaces of the rotor 32 and the stator 33 during passage through the motor chamber 70.

The liquid refrigerant discharged from the discharge flow path 54 is sent back The line 5e is sent to the front portion of the aggregator 8. The liquid refrigerant introduced into the motor chamber 70 of the relatively low pressure from the high pressure pump chamber 60 may generate steam due to the pressure reduction. Alternatively, the liquid refrigerant may be heated by heat exchange with the motor portion 31, that is, the liquid refrigerant may be heated by cooling of the rotor 32 and the stator 33 to generate steam. Therefore, for a portion where the liquid refrigerant does not adversely affect part of the vapor, for example, the front side of the aggregator 8 is conveyed and discharged. 54 discharged liquid refrigerant.

Next, referring to Figure 4, for the deformation of the refrigerant pump 6 In the following, the description of the configuration common to the above-described embodiment will be omitted, and the description will be focused on the differences from the above-described embodiment.

As shown in Fig. 4, the refrigerant pump 6 of the modification is compared with The above embodiment is different in the configuration of the casing 20 for accommodating the internal gear pump 40 and the bearing 25 on the pump side. The motor housing 21 has a bearing chamber 61 in which the bearing 25 is fitted from the motor chamber 70 side and a first diameter having a large diameter in which the internal gear pump 40 is housed from the pump side. Space 68. The bearing 25 inserted into the bearing chamber 61 fixes the outer ring by the bearing support body 27A inserted from the motor chamber 70 side. The first space 68 of the bearing chamber 61 and the pump chamber 60 is partitioned by the partition wall portion 29, and a shaft insertion hole is formed in the partition wall portion 29. The shaft insertion hole of the partition wall portion 29 is sized to be opened in such a manner that the pump side portion of the drive shaft 30 is inserted, and is a tooth of the gear other than the inner rotor 41 of the internal gear pump 40. The diameter of the bottom circle is a small diameter.

On the other hand, the pump housing 22 faces the first space 68 The end surface of the flat portion forms a side surface in the direction of the drive shaft of the rotor chamber 60, and the end surface facing the first space 68 is provided with a second space 69 for accommodating a small diameter of the shaft end of the pump shaft 30. . The pump housing 22 has a convex portion that protrudes toward the motor side, and the convex portion is fitted into the first space 68 of the motor housing 21. The opening diameter of the second space 69 is such that the pump side portion of the drive shaft 30 can be inserted to form an opening, and the ratio is an internal gear pump. Within 40, the size of the small diameter of the outer diameter of the gear of the outer rotor 41 is small.

The refrigerant pump 6 of the modification is formed in the motor housing The pumping chamber 60 is configured by a first space 68 having a large diameter of 21 and a second space 69 formed in a small diameter of the pump casing 22. Next, the pump casing 22 is attached to the side surface on the pump side of the motor casing 21 in a sealed state, and the end cover 23 is attached to the side surface of the motor casing 21 opposite to the pump side in a sealed state. Thereby, the internal gear pump 40 and the motor unit 31 are housed in the casing 20 in a sealed state.

The present invention is not limited to the above embodiment, and can be performed Various changes. For example, in the above-described embodiment, the communication hole formed in the drive shaft 30 is an axial direction communication hole 50 extending from the axial end portion of the pump side in the axial direction to the region facing the first motor chamber 62. And the radial direction communication hole 51 from the axial direction communication hole 50 extending to the opening of the outer peripheral surface of the drive shaft 30 in the direction perpendicular to the axial direction of the drive shaft 30 is not limited thereto. For example, the communication hole may be an axial direction communication hole extending from the opening portion of the shaft end portion on the pump side in the axial direction to a region facing the third motor chamber 64, and the communication hole from the axial direction may be perpendicular to the axis. The radial direction communication hole extends to the opening of the outer peripheral surface of the drive shaft 30 in the intersecting direction. Further, the communication hole may be formed by an axial direction communication hole extending from the opening portion of the shaft end portion on the pump side in the axial direction to the opening portion of the bearing chamber 65 communicating with the motor side, and passing through the bearing chamber. 65 and the bearing 26 are coupled to the third motor chamber 64. As described above, when the communication hole is connected to the third motor chamber 64, as long as it is connected in the double cycle The discharge flow path 54 of the low-pressure line of the power generation system 1 may be connected to the first motor chamber 62.

As indicated above, the present invention provides the following refrigerant pumping.

(1) is a refrigerant pump used in a two-cycle power generation system, the refrigerant pump having: a pumping portion for boosting and discharging the liquefied refrigerant; and a motor portion for driving the pumping portion; a rotational driving force generated by the motor unit is transmitted to a drive shaft of the pumping unit; and a housing having a pump chamber and a motor chamber in which the pump portion and the motor portion are respectively housed in a sealed state; and the pump a gear pump that is disposed at an end of the drive shaft, wherein the drive shaft has a communication hole for communicating the pump chamber and the motor chamber, and the housing has a motor chamber coupled to the motor chamber The discharge flow path of the low pressure line of the aforementioned dual cycle power generation system.

According to the above configuration, the pumping portion can be used as an internal gear pump provided at the end of the drive shaft, and the pumping portion can be miniaturized. Since the refrigerant leakage is prevented by keeping the pump chamber and the motor chamber of the casing in a sealed state, there is no need for a partition wall such as a tank for partitioning the rotor and the stator of the motor portion. Thereby, since the distance between the rotor and the stator can be shortened, the rotor and the stator can be directly cooled, and the motor efficiency can be improved. The rate further realizes miniaturization of the motor unit. By providing the communication hole in the drive shaft, the pump chamber and the motor chamber can be connected without using an external pipe. The housing has a discharge flow path for connecting the motor chamber to the low-pressure line of the dual-cycle power generation system, and the motor chamber can be supplied with refrigerant from the pump chamber through a communication hole provided in the drive shaft without using an additional pump. Therefore, there is an effect of providing a small-sized refrigerant pump with improved motor efficiency and a dual-cycle power generation system in which the overall efficiency of the refrigerant pumping is improved.

(2) The motor chamber has a pump side space on the pump chamber side partitioned by the motor portion, and a pump opposite side space on the opposite side of the pump chamber.

The discharge flow path connects the pump opposite side space to the low pressure line of the two-cycle power generation system.

According to the above configuration, the liquid portion is cooled while the liquid refrigerant is discharged from the discharge flow path by the motor portion.

(3) The motor chamber has a pump side space on the pump chamber side partitioned by the motor portion, and a pump opposite side space on the opposite side of the pump chamber.

The communication hole has an opening that communicates with one of the pump side space and the pump opposite side space.

The casing has a discharge flow path that connects the other of the pump side space and the pump opposite side space to the low pressure line of the two-cycle power generation system.

According to the above configuration, the refrigerant supplied to the pump side space is supplied to the slave pump by providing the communication hole opened in the pump side space. The opposite side space is discharged and can pass through the motor portion reliably. Further, the communication hole may be opened to the opposite side of the pump to connect the pump side space to the low pressure line of the dual cycle power generation system. Thereby, the refrigerant supplied to the space on the opposite side of the pump can surely pass through the motor portion until it is discharged from the pump side space.

(4) The communication hole has an opening on a peripheral surface of the drive shaft.

According to the above configuration, the communication port is opened on the outer peripheral surface of the drive shaft of the rotary shaft, and the refrigerant can be uniformly supplied to the entire circumference in the radial direction covering the opposite side of the pump. Therefore, there is an effect that the entire motor unit can be uniformly cooled.

(5) The low-pressure line of the aforementioned two-cycle power generation system in which the opposite side of the pump is connected is located directly in front of the condenser of the above-described dual-cycle power generation system.

The refrigerant supplied to the motor chamber may be partially vaporized depending on the conditions, and if the refrigerant vapor is introduced into the pump portion, compression failure may occur. According to the above configuration, the refrigerant discharged from the motor unit is supplied to the front side of the condenser of the two-cycle power generation system, and can be reliably returned to the liquid refrigerant before being introduced into the pumping portion. Therefore, there is an effect of providing a refrigerant pump that can reliably deliver the liquid refrigerant and a two-cycle power generation system in which the overall reliability of the refrigerant pumping is improved.

(6) An oil supply flow path for supplying oil to a bearing that supports the drive shaft.

The refrigerant used in the dual-cycle power generation system because of its viscosity It is generally lower, and only when the lubrication of the refrigerant is used, the bearing may be damaged. According to the above configuration, by supplying oil to the bearing, it is possible to supplement the situation in which the lubricating property of the refrigerant alone is insufficient, in other words, it is possible to improve the lubricity at the time of lubrication of the refrigerant.

6‧‧‧Refrigerated pump

20‧‧‧shell

21‧‧‧Motor housing

22‧‧‧ pump housing

23‧‧‧End cover

25‧‧‧ bearing

26‧‧‧ Bearing

27A‧‧‧ bearing support

27B‧‧‧ bearing support

27C‧‧‧ bearing support

28‧‧‧ partition wall

30‧‧‧Drive shaft

31‧‧‧Motor Department

32‧‧‧Rotor

33‧‧‧ Stator

35‧‧‧ gap

40‧‧‧Internal gear pump (pump section)

43‧‧‧Inhalation test

44‧‧‧ spit out

50‧‧‧Axis direction communication hole (connection hole)

51‧‧‧Pathway communication hole (communication hole)

52‧‧‧ oil supply flow path

53‧‧‧ Oil supply flow path

54‧‧‧Draining flow path

60‧‧‧ pumping room

61‧‧‧ bearing room

62‧‧‧1st motor room (pump side space of motor room)

63‧‧‧2nd motor room

64‧‧‧3rd motor room (the opposite side of the pumping of the motor room)

65‧‧‧ bearing room

68‧‧‧1st space

69‧‧‧Second space

70‧‧‧Motor room

Claims (12)

A refrigerant pump is a refrigerant pump used in a dual-cycle power generation system, and the refrigerant pump has a pumping portion for boosting and delivering a liquefied refrigerant, and a motor portion for driving a pumping unit for transmitting a rotational driving force generated by the motor unit to the pumping unit; and a housing for accommodating the pumping unit and the motor unit in a sealed state The pumping chamber and the motor chamber; and the pumping portion is disposed at an end of the driving shaft, and the driving shaft has a communication hole for connecting the pump chamber and the motor chamber. The housing has a discharge flow path for connecting the motor chamber to a low pressure line of the two-cycle power generation system. The refrigerant pump according to the first aspect of the invention, wherein the motor chamber has a pump side space located on the pump chamber side partitioned by the motor portion, and opposite to the pump chamber The side opposite pump side space, the discharge flow path is connected to the pump opposite side space to the low pressure line of the two-cycle power generation system. Such as the refrigerant pump described in the first item of the patent scope, The motor chamber has a pump side space on the pump chamber side partitioned by the motor portion and a pump opposite side space on the opposite side of the pump chamber, and the communication hole has An opening for connecting one of the pump side space and the pump opposite side space, wherein the casing has the other of the pump side space and the pump opposite side space connected to the double cycle power generation The discharge flow path of the low pressure pipeline of the system. The refrigerant pump according to the first aspect of the invention, wherein the communication hole has an opening on a peripheral surface of the drive shaft. The refrigerant pump according to the first aspect of the invention, wherein the low-pressure line of the two-cycle power generation system in which the pump opposite side space is connected is located directly in front of a condenser of the two-cycle power generation system. The refrigerant pump according to claim 1, wherein the refrigerant pumping unit that supplies the bearing that supports the drive shaft to the shaft is provided. A dual-cycle power generation system includes: an evaporator that evaporates a liquefied refrigerant, and a generator that generates electric power by expansion of refrigerant vapor generated by the evaporator; A double-cycle power generation system in which a refrigerant vapor used in a generator is condensed into a liquid refrigerant, and a refrigerant that is pressurized by a refrigerant liquefied by the condenser and pumped and circulated is circulated, and the refrigerant pump is provided. a pumping unit for boosting and delivering the liquefied refrigerant; a motor unit for driving the pumping unit; and a drive shaft for driving the rotational driving force generated by the motor unit And a housing having a pump chamber and a motor chamber that respectively house the pump portion and the motor portion in a sealed state; and the pump portion is disposed at an end of the drive shaft In the internal gear pump, the drive shaft has a communication hole for communicating the pump chamber and the motor chamber, and the housing has a low-pressure line for connecting the motor chamber to the dual-cycle power generation system. The discharge flow path. The two-cycle power generation system according to claim 7, wherein the motor chamber has a pump side space located on the pump chamber side partitioned by the motor portion, and is located in the pump chamber On the opposite side of the pump opposite side space, the discharge flow path connects the pump opposite side space to the low pressure line of the aforementioned two-cycle power generation system. Double cycle power generation system as described in item 7 of the patent application scope The motor chamber has a pump side space on the pump chamber side partitioned by the motor portion, and a pump opposite side space on the opposite side of the pump chamber, the communication hole, And an opening for connecting one of the pump side space and the pump opposite side space, wherein the casing has a connection between the pump side space and the pump opposite side space to the double The discharge flow path of the low pressure pipeline of the circulating power generation system. The double-cycle power generation system according to claim 7, wherein the communication hole has an opening on a peripheral surface of the drive shaft. The dual-cycle power generation system according to claim 7, wherein the low-pressure line of the two-cycle power generation system in which the pump opposite side space is connected is located directly in front of the condenser of the two-cycle power generation system. The dual-cycle power generation system according to claim 7, wherein the oil supply flow path for supplying oil to a bearing that supports the drive shaft is provided.