WO2015129169A1

WO2015129169A1 - Compressor

Info

Publication number: WO2015129169A1
Application number: PCT/JP2015/000552
Authority: WO
Inventors: 雅至井ノ上; 小村　正人; 江原　俊行; 井上　孝
Original assignee: 株式会社デンソー; 株式会社日本自動車部品総合研究所
Priority date: 2014-02-28
Filing date: 2015-02-06
Publication date: 2015-09-03
Also published as: JP2015161268A; JP6399637B2; DE112015001018T5

Abstract

　A compressor is provided with compression-chamber-forming members (11, 12) for forming a compression chamber (Vc) that reduces capacity while being displaced around a rotating shaft (25), and an intermediate pressure intake port (30b) for causing the flow of intermediate-pressure fluid drawn in from the exterior to merge with fluid in the compression process in the compression chamber (Vc). The compressor is further provided with a backflow-preventing section (50) for preventing fluid from flowing back from the compression chamber (Vc) toward the intermediate pressure intake port (30b). A downstream-side fluid passage (51) leading from the backflow-preventing section (50) to the compression chamber (Vc) is formed having at least a directional component extending in the direction opposite the rotational direction of the rotating shaft (25). The region (wall surface) forming the compression chamber (Vc) on the intake side of the compression-chamber-forming member (12) is cooled by the intermediate-pressure refrigerant flowing through the downstream-side refrigerant passage (51), and the heat of a high-pressure refrigerant inside the compression chamber (Vc) on the discharge side is suppressed from being transferred to a refrigerant flowing into the compression chamber (Vc) on the intake side via the compression-chamber-forming member (12).

Description

Compressor

Cross-reference of related applications

This application is based on Japanese Patent Application No. 2014-038337 filed on February 28, 2014, the disclosure of which is incorporated into this application by reference.

The present disclosure relates to a compressor that compresses a fluid in a compression chamber that reduces the volume while being displaced around a rotation axis.

Conventionally, a compressor that compresses a fluid in a compression chamber that reduces the volume while being displaced around a rotation axis (hereinafter referred to as a rotary type volume compressor) is known. For example, as an example of this type of rotary volumetric compressor, there is a scroll compressor including a fixed scroll and a movable scroll each having a spiral tooth portion.

More specifically, in the scroll compressor, the movable scroll is swung (revolved) with respect to the fixed scroll in a state where the spiral tooth portions formed on the movable scroll and the fixed scroll are engaged with each other. Thereby, the volume of the compression chamber is reduced while displacing the compression chamber formed between the respective tooth portions around the rotation axis.

Patent Document 1 discloses a compressor applied to a so-called gas injection cycle (economizer-type refrigeration cycle), in which an intermediate pressure fluid that is sucked from outside is joined to a fluid in a compression process in a compression chamber. A scroll compressor provided with a suction port is disclosed. In a compressor provided with such an intermediate pressure suction port, the compression efficiency of the compressor can be improved by joining an intermediate pressure fluid having a relatively low temperature into the compression chamber.

Note that the compression efficiency of the compressor is a value defined by the ratio of the work output from the compressor to the work required to drive the compressor.

JP 2013-209954 A

Incidentally, a general rotary volumetric compressor includes a compression chamber forming member that partitions and forms a compression chamber. Then, a part of the compression chamber forming member is rotationally displaced along with the rotation of the rotation shaft, and a portion (wall surface) of the compression chamber forming member that actually forms the compression chamber is continuously changed around the rotation axis. Thereby, the compression chamber is displaced around the rotation axis.

That is, in the rotary type volume compressor, the suction side compression chamber communicating with the suction port side for sucking low pressure fluid and the discharge side compression chamber communicating with the discharge port side for discharging high pressure fluid are the same compression chamber. A compartment is formed by the forming member.

This will be described by taking a scroll compressor as an example. The scroll compressor includes a fixed scroll and a movable scroll as compression chamber forming members. Then, the movable scroll is turned (revolved) with respect to the fixed scroll, and the position where the movable side tooth portion of the movable scroll contacts the fixed side tooth portion of the fixed scroll is gradually changed around the rotation axis. Thereby, the wall surface forming the compression chamber is continuously changed to displace the compression chamber around the rotation axis.

Therefore, the compression chamber on the suction side formed on the outer peripheral side and the compression chamber on the discharge side formed on the center side are partitioned by the same fixed scroll and movable scroll.

According to studies by the inventors of the present disclosure, the temperature of the fluid in the compression chamber increases as it is compressed, so the fluid temperature in the compression chamber on the discharge side is higher than the fluid temperature sucked into the compression chamber on the suction side. Also gets higher. For this reason, in a configuration in which the discharge-side compression chamber and the suction-side compression chamber are partitioned by the same compression chamber forming member, such as a rotary type volume compressor, the heat of the high-pressure fluid in the discharge-side compression chamber However, heat is easily transferred to the fluid flowing into the compression chamber on the suction side via the compression chamber forming member.

When the heat of the high-pressure fluid in the discharge-side compression chamber is transferred to the fluid flowing into the suction-side compression chamber, the density of the fluid flowing into the suction-side compression chamber is reduced, and the volumetric efficiency of the compressor Will get worse.

The volumetric efficiency of the compressor is a value defined by the ratio of the amount of fluid actually sucked into the compression chamber to the volume that the compression chamber theoretically shrinks. Therefore, the discharge flow rate of the compressor at the same rotation speed can be improved by improving the volumetric efficiency.

Thereby, for example, in a compressor applied to a refrigeration cycle, the number of revolutions required to exhibit the same cooling capacity or heating capacity can be reduced by improving the volumetric efficiency. As a result, the reliability of the compressor can be improved and the coefficient of performance (COP) of the refrigeration cycle can be improved.

In view of the above points, an object of the present disclosure is to provide a compressor capable of suppressing deterioration in volume efficiency of a compressor that compresses fluid in a compression chamber that reduces the volume while being displaced around a rotation axis.

The compressor of the present disclosure includes a compression chamber forming member that forms a compression chamber that reduces the volume while being displaced around a rotation axis, and an intermediate that joins an intermediate pressure fluid sucked from the outside to a fluid in a compression process in the compression chamber. And a pressure suction port.

The compressor further includes a backflow prevention unit that prevents the fluid from flowing back from the compression chamber toward the intermediate pressure suction port. A downstream fluid passage extending from the backflow prevention unit to the compression chamber is formed with a directional component extending at least in the direction opposite to the rotation direction of the rotation shaft.

According to this, the downstream fluid passage is formed with a directional component extending in the direction opposite to the rotation direction of the rotation shaft. Accordingly, the intermediate pressure fluid flowing through the downstream fluid passage can cool the wall surface of the compression chamber forming member that forms the low pressure side compression chamber whose fluid pressure is relatively low.

Accordingly, the heat of the high-pressure fluid in the discharge-side compression chamber that communicates with the discharge port that discharges the high-pressure fluid flows into the suction-side compression chamber that communicates with the suction port that sucks in the low-pressure fluid via the compression chamber forming member. It is possible to suppress the heat transfer to the fluid to be performed and suppress the deterioration of the volume efficiency of the compressor.

Further, the compressor of the present disclosure may be specifically configured as a scroll type compressor. In this case, the compression chamber forming member revolves by the rotational driving force transmitted from the rotation shaft, and the movable scroll having a spiral movable side tooth portion, and the spiral fixed side tooth portion meshing with the movable side tooth portion. A fixed scroll having The compression chamber is formed between the movable side tooth portion and the fixed side tooth portion.

It is a whole block diagram of the heat pump cycle of 1st Embodiment. It is an axial sectional view of the compressor of a 1st embodiment. FIG. 3 is a cross-sectional view taken along the line III-III in FIG. FIG. 4 is an enlarged cross-sectional view of the IV-IV cross section of FIG. 3, and is a cross-sectional view for explaining the shape of the downstream refrigerant passage of the first embodiment. It is sectional drawing for demonstrating the shape of the downstream refrigerant path of 2nd Embodiment. It is sectional drawing for demonstrating the shape of the downstream refrigerant path of 3rd Embodiment.

(First embodiment)
A first embodiment of the present disclosure will be described with reference to FIGS. In the present embodiment, the compressor 1 according to the present disclosure is applied to a heat pump cycle (vapor compression refrigeration cycle) 100 that heats hot water using a heat pump hot water heater. Therefore, the fluid compressed by the compressor 1 of this embodiment is a refrigerant.

The heat pump cycle 100 is configured as a gas injection cycle in which the intermediate pressure gas-phase refrigerant of the cycle is merged with the refrigerant in the pressurizing process in the compression chamber Vc of the compressor 1. More specifically, the heat pump cycle 100 of the present embodiment includes a compressor 1, a water-refrigerant heat exchanger 2, a first expansion valve 3, a gas-liquid separator 4, a second expansion valve, as shown in FIG. 5. It has the outdoor heat exchanger 6 grade | etc.,.

The water-refrigerant heat exchanger 2 is a heating heat exchanger that heats hot water by exchanging heat between the refrigerant discharged from the discharge port 40a of the compressor 1 and the hot water. The first expansion valve 3 is a high-stage decompression unit that decompresses the high-pressure refrigerant flowing out of the water-refrigerant heat exchanger 2 until it becomes an intermediate-pressure refrigerant. Further, the first expansion valve 3 is an electric expansion valve whose operation is controlled by a control signal output from a control device (not shown).

The gas-liquid separator 4 is a gas-liquid separator that separates the gas-liquid of the intermediate pressure refrigerant decompressed by the first expansion valve 3. The second expansion valve 5 is a low-stage decompression unit that decompresses the intermediate-pressure liquid-phase refrigerant flowing out from the liquid-phase refrigerant outlet of the gas-liquid separator 4 until it becomes a low-pressure refrigerant. The basic configuration of the second expansion valve 5 is the same as the basic configuration of the first expansion valve 3. The outdoor heat exchanger 6 is a heat absorption heat exchanger that evaporates the low-pressure refrigerant decompressed by the second expansion valve 5 by exchanging heat with the outside air.

A suction port 30 a of the compressor 1 is connected to the refrigerant outlet side of the outdoor heat exchanger 6, and an intermediate pressure suction port 30 b of the compressor 1 is connected to the gas-phase refrigerant outlet of the gas-liquid separator 4. Yes. Therefore, in this embodiment, the intermediate-pressure gas-phase refrigerant separated by the gas-liquid separator 4 is injected into the refrigerant in the pressurizing process in the compression chamber Vc of the compressor 1.

Further, in the heat pump cycle 100 of the present embodiment, carbon dioxide is employed as the refrigerant. The heat pump cycle 100 constitutes a supercritical refrigeration cycle in which the pressure of the high-pressure side refrigerant in the cycle from the discharge port of the compressor 1 to the inlet of the first expansion valve 3 is equal to or higher than the critical pressure. Furthermore, the refrigerant is mixed with oil (refrigeration oil) that lubricates each sliding portion inside the compressor 1, and a part of this oil circulates in the cycle together with the refrigerant.

In addition, the heat pump type hot water heater has a hot water storage tank, a hot water circulation circuit, a water pump (all not shown) and the like in addition to the heat pump cycle 100. The hot water storage tank stores hot water heated by the water-refrigerant heat exchanger 2. The hot water circulation circuit circulates hot water between the hot water storage tank and the water-refrigerant heat exchanger 2. The water pump is disposed in the hot water circulation circuit and pumps hot water.

Next, the detailed configuration of the compressor 1 will be described with reference to FIGS. In addition, the up and down arrows in FIG. 2 indicate the up and down directions in a state where the compressor 1 is mounted on the heat pump type hot water heater. The compressor 1 includes a compression mechanism unit 10, an electric motor unit (electric motor unit) 20, a housing 30, an oil separator 40, and the like.

The compression mechanism unit 10 sucks, compresses and discharges a refrigerant that is a compression target fluid. The electric motor unit 20 outputs a rotational driving force that drives the compression mechanism unit 10. The housing 30 forms an outer shell of the compressor 1 and houses the compression mechanism unit 10 and the electric motor unit 20 therein. The oil separator 40 is disposed outside the housing 30 and separates oil from the high-pressure refrigerant compressed by the compression mechanism unit 10.

Further, in the compressor 1 of the present embodiment, as shown in FIG. 2, a shaft (rotating shaft) 25 that transmits a rotational driving force from the electric motor unit 20 to the compression mechanism unit 10 extends in the vertical direction (vertical direction). The compression mechanism unit 10 and the electric motor unit 20 are arranged in the vertical direction. That is, the compressor 1 of the present embodiment is a so-called vertical type. More specifically, in the compressor 1 of the present embodiment, the compression mechanism unit 10 is disposed on the lower side of the electric motor unit 20.

The housing 30 includes a cylindrical member 31 whose central axis extends in the vertical direction, a bowl-shaped upper lid member 32 that blocks the upper end of the cylindrical member 31, and a bowl-shaped lower lid member 33 that blocks the lower end of the cylindrical member 31. . The housing 30 has a sealed container structure in which a cylindrical member 31, an upper lid member 32, and a lower lid member 33 are integrally joined. The cylindrical member 31, the upper lid member 32, and the lower lid member 33 are all made of iron or an iron-based metal, and these are joined by welding.

The housing 30 is formed with a suction port 30a, an intermediate pressure suction port 30b (not shown in FIG. 2), and a high-pressure refrigerant outlet (not shown in FIG. 2).

The suction port 30a is a refrigerant suction port through which the low-pressure refrigerant flowing out of the outdoor heat exchanger 6 is sucked into the compression mechanism unit 10. The intermediate pressure suction port 30 b is an intermediate pressure refrigerant suction port that joins the intermediate pressure gas phase refrigerant flowing out from the gas phase refrigerant outlet of the gas-liquid separator 4 with the refrigerant in the compression process in the compression chamber Vc of the compression mechanism unit 10. . The high-pressure refrigerant outlet is a refrigerant outlet that allows the high-pressure refrigerant discharged from the compression mechanism unit 10 to flow out toward the oil separator 40 disposed outside the housing 30.

The electric motor unit 20 includes a coil stator 21 that forms a stator and a rotor 22 that forms a rotor. A shaft 25 is fixed to the shaft center hole of the rotor 22 by press-fitting. Therefore, when electric power is supplied from the control device to the coils of the coil stator 21 and a rotating magnetic field is generated, the rotor 22 and the shaft 25 rotate together.

The shaft 25 is formed in a substantially cylindrical shape, and both end portions thereof are rotatably supported by a first bearing portion 26 and a second bearing portion 27 that are configured by sliding bearings, respectively. Further, an oil supply passage 25 a for supplying oil to the sliding portion between the outer surface of the shaft 25 and the first and

second bearing portions

26 and 27 is formed inside the shaft 25.

The first bearing portion 26 is formed in a middle housing 28 that partitions the space in the housing 30 into a space in which the electric motor portion 20 is disposed and a space in which the compression mechanism portion 10 is disposed. The first bearing part 26 supports the lower end side (compression mechanism part 10 side) of the shaft 25. The 2nd bearing part 27 is being fixed to the cylindrical member 31 of the housing 30 via the interposition member, and is supporting the upper end side (opposite side of the compression mechanism part 10) of the shaft 25. FIG.

The compression mechanism unit 10 is configured as a scroll type compression mechanism unit having a movable scroll 11 and a fixed scroll 12 each having a spiral tooth portion. The movable scroll 11 is disposed below the middle housing 28 described above, and the fixed scroll 12 is disposed below the movable scroll 11.

More specifically, the movable scroll 11 has a disk-shaped movable side substrate portion 111 and a spiral movable side tooth portion 112 protruding from the movable side substrate portion 111 toward the fixed scroll 12. The fixed scroll 12 has a disk-shaped fixed side substrate portion 121 and a spiral fixed side tooth portion 122 protruding from the fixed side substrate portion 121 toward the movable scroll 11.

Further, the fixed scroll 12 is fixed to the housing 30 by press-fitting the outer peripheral side surface of the fixed-side substrate 121 to the inner peripheral side surface of the cylindrical member 31 of the housing 30. The movable scroll 11 is disposed in a space formed between the middle housing 28 and the fixed scroll 12.

The movable scroll 11 and the fixed scroll 12 are arranged so that the plate surfaces of the

substrate portions

111 and 121 face each other. The tooth portion 112 of the movable scroll 11 and the tooth portion 122 of the fixed scroll 12 are engaged with each other, and the tip portion of the tooth portion of one scroll is in contact with the substrate portion of the other scroll.

A tip seal for improving the airtightness of the compression chamber Vc (working chamber V) is disposed at the tip of each scroll tooth. More specifically, a spiral groove along the shape of the tip is formed at the tip of each scroll tooth, and the tip seal is arranged in a spiral by being fitted into this groove. ing. Such a chip seal is made of, for example, PEEK (polyether ether ketone) resin.

Thereby, each tooth part 112,122 contacts in several places, and when it sees from the axial direction of the central axis of the shaft 25 between each tooth part 112,122, it forms in a crescent moon shape. A plurality of compression chambers Vc are formed. 2 and 3, for the sake of clarity of illustration, only some of the compression chambers Vc are provided with reference numerals, and other compression chambers are omitted. Yes.

A cylindrical boss portion 113 into which the lower end portion of the shaft 25 (end portion on the compression mechanism portion 10 side) is inserted is formed at the center portion on the upper surface side of the movable side substrate portion 111 of the movable scroll 11. . On the other hand, the lower end portion of the shaft 25 is an eccentric portion 25 b that is eccentric with respect to the rotation center of the shaft 25. Accordingly, the eccentric portion 25 b of the shaft 25 is inserted into the boss portion 113 of the movable side substrate portion 111 of the movable scroll 11.

Furthermore, between the movable scroll 11 and the middle housing 28, a rotation prevention mechanism (not shown) for preventing the movable scroll 11 from rotating around the eccentric portion 25b is provided. For this reason, when the shaft 25 rotates, the movable scroll 11 turns (revolves) with the rotation center of the shaft 25 as the revolution center without rotating around the eccentric portion 25b.

By this revolving motion, the compression chamber Vc described above is displaced around the shaft 25 while reducing the volume from the outer peripheral side to the center side while reducing the volume. Therefore, the compressor 1 of the present embodiment is configured as a rotary type volume compressor, and the movable scroll 11 and the fixed scroll 12 constitute a compression chamber forming member.

Further, the suction port 30a formed in the housing 30 communicates with the compression chamber Vc on the suction side which is positioned on the outermost peripheral side of the compression chamber Vc and has the largest volume. The intermediate pressure suction port 30b communicates with the compression chamber Vc at an intermediate position that is positioned at an intermediate position in the process of displacement from the outermost peripheral side to the center side of the compression chamber Vc.

Further, at least a part of the refrigerant passage for suction from the suction port 30a to the compression chamber Vc on the suction side, and at least a part of the refrigerant passage for injection from the intermediate pressure suction port 30b to the compression chamber Vc at the intermediate position are It is formed inside the fixed side substrate 121 of the fixed scroll 12.

Further, a backflow prevention valve 50 is arranged in the refrigerant passage for injection from the intermediate pressure suction port 30b to the compression chamber Vc at the intermediate position. The backflow prevention valve 50 is a backflow prevention unit for preventing the refrigerant from flowing back from the compression chamber Vc toward the intermediate pressure suction port 30b.

More specifically, the backflow prevention valve 50 of the present embodiment is configured by a reed valve 50a formed of a plate-like member and a seat member 50b formed with a passage that opens and closes the reed valve 50a. Such a reed valve type backflow prevention valve 50 can be accommodated in a relatively small accommodation space, and therefore, the internal volume (dead volume) of the refrigerant passage downstream from the backflow prevention valve 50 in the injection refrigerant passage. ) Is effective in that it does not unnecessarily expand.

Further, in the scroll type compression mechanism section 10 of the present embodiment, as shown in the cross-sectional view of FIG. 3, two independent compression chambers Vc are formed at positions symmetrical with respect to the central axis of the shaft 25. Yes. Therefore, the same number (two in the present embodiment) of backflow prevention valves 50 as the compression chambers Vc are provided so as to prevent backflow from the compression chambers Vc formed independently of each other.

Furthermore, in the present embodiment, the direction in which the refrigerant passage on the downstream side of the backflow prevention valve 50 in the injection refrigerant passage extends is inclined with respect to the central axis direction of the shaft 25 as shown in FIGS. ing. That is, the refrigerant passage is a downstream refrigerant passage (downstream fluid passage) 51 from the backflow prevention valve 50 to the compression chamber Vc at the intermediate position.

As shown in FIG. 3, when viewed from the axial direction of the central axis of the shaft 25, a line passing through the inlet portion of the downstream refrigerant passage 51 and the central axis of the shaft 25 is defined as a line L <b> 1 and the inlet of the downstream refrigerant passage 51. A line passing through the part and the outlet part is defined as a line L2, and an angle from the line L1 to the line L2 in the rotational direction of the shaft 25 and the movable scroll 11 is defined as α. The angle α is set so as to satisfy the following formula F1.

0 ° <α <180 ° (F1)
Thereby, the downstream side refrigerant passage 51 is formed having a directional component toward the wall surface forming the compression chamber Vc.

Further, as shown in FIG. 4, in a cross section that intersects the line L2 and is parallel to the axial direction of the shaft 25, the line extending in the axial direction of the shaft 25 is defined as a line L3, and between the line L3 and the line L2. Of the formed angles, the smaller angle is β. The angle β is set so as to satisfy the following formula F2.

0 ° <β <90 °… (F2)
As a result, the downstream refrigerant passage 51 is formed with a directional component parallel to the axial direction of the shaft 25.

And by satisfy | filling said numerical formula F1 and F2, the downstream refrigerant path 51 has a direction component extended in the reverse direction to the rotation direction of the shaft 25 and the movable scroll 11, and is formed. Furthermore, in the present embodiment, the downstream refrigerant passage 51 is formed to have a directional component toward the wall surface forming the suction-side compression chamber Vc of the fixed scroll 12.

Note that the downstream refrigerant passage 51 in the present embodiment is a refrigerant passage on the downstream side of the check valve 50. Accordingly, a housing space for displacing the reed valve 50 a provided as a part of the check valve 50 is not included in the downstream refrigerant passage 51.

Further, a discharge hole 123 through which the refrigerant compressed in the compression chamber Vc is discharged is formed at the center of the fixed side substrate 121 on the fixed scroll 12 side. Further, a discharge chamber 124 communicating with the discharge hole 123 is formed below the discharge hole 123. The discharge chamber 124 is provided with a discharge valve (reed valve) that forms a check valve that prevents the refrigerant from flowing backward from the discharge chamber 124 to the compression chamber Vc, and a stopper 16 that regulates the maximum opening of the discharge valve. .

Inside the housing 30, a refrigerant passage (not shown) that guides the refrigerant from the discharge chamber 124 to the refrigerant outlet formed in the housing 30 is formed. Further, a refrigerant inlet 40b of the oil separator 40 is connected to the refrigerant outlet. The oil separator 40 includes a cylindrical member 41 extending in the vertical direction, and the refrigerant pressurized by the compression mechanism unit 10 is swirled in a space formed therein, and the gas phase refrigerant and the oil are subjected to centrifugal force. And are separated.

The high-pressure gas-phase refrigerant separated by the oil separator 40 is discharged to the water-refrigerant heat exchanger 2 from a discharge port 40a formed on the upper side of the oil separator 40. On the other hand, the oil separated by the oil separator 40 is stored in a lower part of the oil separator 40, and the compression mechanism portion 10 in the housing 30 and the shaft 25 and the first, Supplied to a sliding portion with the

second bearing portions

26 and 27 and the like.

Next, the operation of the compressor 1 of the present embodiment having the above configuration will be described. When electric power is supplied to the electric motor unit 20 of the compressor 1 and the rotor 22 and the shaft 25 rotate, the movable scroll 11 turns (revolves) with respect to the shaft 25. Accordingly, the crescent-shaped compression chamber Vc formed between the movable side tooth portion 112 of the movable scroll 11 and the fixed side tooth portion 122 of the fixed scroll 12 moves while turning around the shaft 25 from the outer peripheral side to the center side. I will do it.

At this time, the low-pressure refrigerant flowing out of the outdoor heat exchanger 6 is sucked into the suction-side compression chamber Vc positioned on the outermost peripheral side and communicated with the suction port 30a through the suction port 30a. The compression chamber Vc into which the low-pressure refrigerant has flowed moves to an intermediate position communicating with the downstream-side refrigerant passage 51 while reducing the volume of the compression chamber Vc as the shaft 25 rotates.

When the compression chamber Vc moves to the intermediate position and the pressure P2 of the intermediate-pressure gas-phase refrigerant on the intermediate pressure suction port 30b side is higher than the pressure P1 of the refrigerant on the compression chamber Vc side, the pressure P1 and the pressure P2 The check valve 50 opens due to the pressure difference. As a result, the intermediate-pressure gas-phase refrigerant separated by the gas-liquid separator 4 and sucked from the intermediate-pressure suction port 30b is injected into the compression chamber Vc.

Further, when the volume of the compression chamber Vc is reduced with the rotation of the shaft 25 and the pressure P1 of the refrigerant on the compression chamber Vc side exceeds the pressure P2 of the intermediate pressure gas phase refrigerant on the intermediate pressure suction port 30b side, the pressure P1 and the pressure The backflow prevention valve 50 closes due to the pressure difference with P2. This prevents the refrigerant from flowing backward from the compression chamber Vc toward the intermediate pressure suction port 30b.

Further, when the compression chamber Vc moves to a position communicating with the discharge hole 123 of the fixed scroll 12 on the center side as the shaft 25 rotates, and the pressure of the high-pressure refrigerant in the compression chamber Vc exceeds the valve opening pressure of the discharge valve. The discharge valve opens. As a result, the high-pressure refrigerant is discharged into the discharge chamber 124. The high-pressure refrigerant discharged to the discharge chamber 124 is separated from the oil by the oil separator 40 and discharged from the discharge port 40a to the water-refrigerant heat exchanger 2.

As described above, in the heat pump cycle 100, the compressor 1 of the present embodiment can suck the refrigerant, compress it, and discharge it.

Here, in the compressor 1 (scroll type compressor) of the present embodiment, a part of the compression chamber forming member (specifically, the movable scroll 11 and the fixed scroll 12) that partitions the compression chamber Vc is rotationally displaced. Thus, the compression chamber Vc is displaced around the shaft 25 by continuously changing the portion (wall surface) of the compression chamber forming member that actually forms the compression chamber Vc. More specifically, in the compressor 1 of the present embodiment, the movable scroll 11 is rotationally displaced, and the wall surface that actually defines the compression chamber Vc among the compression chamber forming members is continuously changed, thereby compressing. The chamber Vc is displaced around the shaft 25.

That is, in the compressor 1 of the present embodiment, both the suction side compression chamber Vc communicating with the suction port 30a and the discharge side compression chamber Vc communicating with the discharge port 40a are defined by the same compression chamber forming member. ing.

Further, since the temperature of the refrigerant in the compression chamber Vc increases as it is compressed, the temperature of the high-pressure refrigerant in the discharge-side compression chamber Vc is higher than the temperature of the low-pressure refrigerant sucked into the suction-side compression chamber Vc. Get higher. For this reason, in a rotary displacement compressor represented by a scroll compressor, the heat of the high-pressure refrigerant in the discharge-side compression chamber Vc flows into the suction-side compression chamber Vc via the compression chamber forming member. Heat is easily transferred to low-pressure refrigerant.

When the heat of the high-pressure refrigerant in the discharge-side compression chamber Vc is transferred to the low-pressure refrigerant flowing into the suction-side compression chamber Vc, the density of the fluid flowing into the suction-side compression chamber Vc decreases, The volumetric efficiency of the compressor deteriorates.

In contrast, in the compressor 1 of the present embodiment, the downstream refrigerant passage 51 has a directional component extending in the direction opposite to the rotation direction of the shaft 25. Therefore, the portion of the fixed scroll 12 that forms the suction-side compression chamber Vc can be cooled by the intermediate pressure refrigerant flowing through the downstream-side refrigerant passage 51.

Thereby, the heat of the high-pressure refrigerant in the compression chamber Vc on the discharge side is suppressed from being transferred to the refrigerant flowing into the compression chamber Vc on the suction side via the fixed scroll 12, and the volume of the compressor 1 is reduced. The deterioration of efficiency can be suppressed. Thereby, the discharge flow rate of the compressor 1 at the same rotation speed can be improved.

As a result, it is possible to reduce the number of revolutions necessary for the water-refrigerant heat exchanger 2 to exhibit the same hot water heating capability. Therefore, the reliability of the compressor 1 can be improved and the coefficient of performance (COP) of the heat pump cycle 100 can be improved.

Further, in the compressor 1 of the present embodiment, the downstream side refrigerant passage 51 is connected to the shaft 25 so that the angle α shown in FIG. 3 satisfies the formula F1 and the angle β shown in FIG. 4 satisfies the formula F2. Inclined with respect to the central axis. Therefore, it is possible to make the shape having a direction component extending in the direction opposite to the rotation direction of the shaft 25 without complicating the passage configuration of the downstream refrigerant passage 51.

Furthermore, the downstream refrigerant passage 51 is formed inside the fixed scroll 12 and has a directional component toward the wall surface forming the suction-side compression chamber Vc in the fixed scroll 12. Therefore, the temperature rise of the wall surface forming the suction side compression chamber Vc is suppressed, and the refrigerant flowing into the suction side compression chamber Vc is heated by the heat of the high-pressure refrigerant in the discharge side compression chamber Vc. This can be effectively suppressed.

Furthermore, the downstream refrigerant passage 51 is formed with a directional component parallel to the axial direction. Thereby, the wide range of the wall surface which forms the compression chamber Vc among the fixed scrolls 12 can be cooled by the intermediate pressure refrigerant flowing through the downstream refrigerant passage 51. Therefore, it is possible to effectively prevent the refrigerant flowing into the suction-side compression chamber Vc from being heated by the heat of the high-pressure refrigerant in the discharge-side compression chamber Vc.

Further, in the heat pump cycle 100 of the present embodiment, carbon dioxide is employed as the refrigerant, and a supercritical refrigeration cycle is configured in which the pressure of the high-pressure side refrigerant is equal to or higher than the critical pressure. In such a supercritical refrigeration cycle, the temperature of the discharge refrigerant discharged from the compressor 1 tends to be relatively high (for example, 90 ° C. or higher), and is sucked by the heat of the high-pressure refrigerant in the discharge-side compression chamber Vc. The refrigerant flowing into the compression chamber Vc on the side is likely to be heated. Therefore, the effect of suppressing the deterioration of volume efficiency by the compressor 1 of the present embodiment is extremely effective.
(Second Embodiment)
In the present embodiment, the shape of the downstream refrigerant passage 51 is changed as shown in FIG. 5 with respect to the first embodiment. FIG. 5 is a drawing corresponding to FIG. 4 of the first embodiment, and the same or equivalent parts as in the first embodiment are denoted by the same reference numerals. The same applies to the following drawings.

Specifically, the downstream-side refrigerant passage 51 of the present embodiment is formed inside the fixed-side tooth portion 122 of the fixed scroll 12. Further, the outlet portion of the downstream refrigerant passage 51 is open to the side surface of the fixed side tooth portion 122. Other configurations and operations are the same as those in the first embodiment.

Therefore, also in the compressor 1 of this embodiment, the effect of suppressing the deterioration of volume efficiency can be obtained as in the first embodiment. Further, in the present embodiment, the downstream refrigerant passage 51 is formed inside the fixed side tooth portion 122 of the fixed scroll 12. Thereby, the downstream refrigerant passage 51 can be brought close to the suction-side compression chamber Vc, and the portion of the fixed scroll 12 that forms the suction-side compression chamber Vc can be effectively cooled.
(Third embodiment)
In the present embodiment, the shape of the downstream refrigerant passage 51 is changed as shown in FIG. 6 with respect to the first embodiment. FIG. 6 is a drawing corresponding to FIG. 4 of the first embodiment. Specifically, the downstream refrigerant passage 51 of the present embodiment has its passage cross-sectional area gradually expanding toward the flow direction of the intermediate pressure refrigerant. Other configurations and operations of the present embodiment are the same as those of the first embodiment.

Therefore, also in the compressor 1 of the present embodiment, the effect of suppressing the deterioration of the volume efficiency can be obtained as in the first embodiment. Furthermore, in this embodiment, since the passage cross-sectional area of the downstream refrigerant passage 51 gradually increases in the flow direction of the intermediate pressure refrigerant, the intermediate pressure fluid is ejected over a wide range in the compression chamber Vc at the intermediate position. be able to.

Therefore, the intermediate pressure refrigerant injected into the compression chamber Vc at the intermediate position efficiently cools the wide range of the compression chamber Vc, and the suction side compression is performed by the heat of the high-pressure refrigerant in the discharge side compression chamber Vc. It can suppress that the refrigerant | coolant which flows in into the chamber Vc will be heated.
(Other embodiments)
The present disclosure is not limited to the above-described embodiment, and can be variously modified as follows without departing from the spirit of the present disclosure.

(1) In the above-described embodiment, the example in which the compressor 1 according to the present disclosure is applied to the heat pump cycle 100 of the heat pump hot water heater has been described. However, the application of the compressor 1 is not limited thereto. That is, the compressor 1 can be applied to a wide range of uses as a compressor that compresses various fluids.

Furthermore, the compressor 1 may be applied to a gas injection cycle including a compressor, a radiator, a branching section, a high stage side expansion valve, an internal heat exchanger, a low stage side expansion valve, and an evaporator. The compressor compresses and discharges the refrigerant. The radiator causes heat exchange between the high-pressure refrigerant discharged from the compressor and the fluid to be heated (or outside air). The branch portion branches the flow of the high-pressure refrigerant that has flowed out of the radiator. The high stage side expansion valve depressurizes one of the high-pressure refrigerants branched at the branching portion until it becomes an intermediate-pressure refrigerant. The internal heat exchanger exchanges heat between the other high-pressure refrigerant branched at the branch portion and the intermediate-pressure refrigerant decompressed by the high-stage side expansion valve. The low stage side expansion valve depressurizes the high-pressure refrigerant that has flowed out of the internal heat exchanger until it becomes a low-pressure refrigerant. The evaporator exchanges heat between the low-pressure refrigerant flowing out from the low-stage side expansion valve and the outside air (or the fluid to be cooled) to evaporate the low-pressure refrigerant. The intermediate pressure refrigerant flowing out from the internal heat exchanger is sucked into the intermediate pressure suction port 30b of the compressor 1. The low-pressure refrigerant flowing out from the evaporator is sucked into the suction port 30a of the compressor 1.

(2) In the above-described embodiment, the compressor 1 configured as a scroll compressor has been described, but the type of the compressor is not limited to this. That is, the compressor of the present disclosure includes a wide variety of compressors that compress fluid in a compression chamber that reduces the volume while being displaced around the rotation axis.

For example, the compression chamber forming member is in contact with the outer peripheral surface of the rotor from the inner peripheral surface side of the cylinder that forms a cylindrical space, the cylindrical rotor that is arranged eccentrically with respect to the central axis of the cylindrical space You may have the vane which protrudes like this. The compression chamber may be configured as a so-called rolling piston compressor formed by a space partitioned by the inner peripheral surface of the cylinder, the outer peripheral surface of the rotor, and the vanes.

Further, the compression chamber forming member protrudes so as to come into contact with the inner peripheral surface of the cylinder from the cylinder forming the columnar space having an elliptical cross section, the columnar rotor disposed inside the columnar space, and the outer peripheral surface side of the rotor. You may have a vane to do. The compression chamber may be configured as a so-called vane type compressor formed by a space partitioned by the inner peripheral surface of the cylinder, the outer peripheral surface of the rotor, and the vanes.

(3) In the above-described embodiment, the vertical type compressor 1 has been described. However, a horizontal type compressor in which the shaft (rotating shaft) 25 extends in the horizontal direction and the compression mechanism unit 10 and the electric motor unit 20 are arranged in the horizontal direction (lateral direction) may be used.

(4) In the above-described embodiment, an example in which the backflow prevention valve 50 configured to include the reed valve 50a is used as the backflow prevention unit has been described, but the backflow prevention unit is not limited thereto. For example, a backflow prevention unit that includes a free valve (spool valve) that is displaced according to the differential pressure between the refrigerant pressure P1 on the compression chamber Vc side and the refrigerant pressure P2 on the intermediate pressure suction port 30b side is employed. May be.

Claims

A compression chamber forming member (11, 12) that forms a compression chamber (Vc) that reduces the volume while being displaced around the rotation axis (25), and intermediate pressure fluid sucked from outside is compressed in the compression chamber (Vc). A compressor comprising an intermediate pressure suction port (30b) for joining the fluid in the compression process,
A backflow prevention unit (50) for preventing the fluid from flowing back from the compression chamber (Vc) toward the intermediate pressure suction port (30b);
A downstream fluid passage (51) extending from the backflow prevention part (50) to the compression chamber (Vc) is formed to have at least a directional component extending in the direction opposite to the rotation direction of the rotation shaft (25). Compressor.
The downstream fluid passage (51) is formed in the compression chamber forming member (12) and has a directional component toward the wall surface forming the compression chamber (Vc) of the compression chamber forming member (12). The compressor according to claim 1, wherein the compressor is formed.
Furthermore, the downstream fluid passage (51) is formed on a wall surface forming the compression chamber (Vc) on the suction side communicating with the suction port (30a) side for sucking low-pressure fluid in the compression chamber forming member (12). The compressor according to claim 2, wherein the compressor is formed to have a directional component.
The compressor according to any one of claims 1 to 3, wherein the downstream fluid passage (51) is formed to have a direction component parallel to an axial direction of the rotating shaft (25).
The compressor according to any one of claims 1 to 4, wherein a passage cross-sectional area of the downstream fluid passage (51) gradually increases in a flow direction of the intermediate pressure fluid.
The compression chamber forming member is
A movable scroll (11) that revolves by a rotational driving force transmitted from the rotary shaft (25) and has a spiral movable side tooth portion (112), and a spiral shape that meshes with the movable side tooth portion (112). A fixed scroll (12) having fixed side teeth (122);
The compressor according to any one of claims 1 to 5, wherein the compression chamber (Vc) is formed between the movable side tooth portion (112) and the fixed side tooth portion (122).
The compressor according to claim 6, wherein the downstream fluid passage (51) is formed inside the fixed tooth portion (122).
The compressor according to any one of claims 1 to 7, wherein the fluid is carbon dioxide.