JP6464502B2 - Refrigeration cycle equipment - Google Patents

Description

  The present invention relates to a refrigeration cycle apparatus.

  Conventionally, as a refrigeration cycle apparatus, a refrigeration cycle apparatus using a chlorofluorocarbon refrigerant or an alternative chlorofluorocarbon refrigerant has been widely used. However, these refrigerants have problems such as destruction of the ozone layer or global warming. Therefore, a refrigeration cycle apparatus using an evaporating liquid such as water as a refrigerant having a small load on the global environment has been proposed.

  Patent Document 1 describes an evaporative cooling apparatus that includes an evaporator, a cooling location, a centrifugal compressor, a roots compressor, and a condenser as a refrigeration cycle apparatus. The evaporator evaporates an evaporating liquid such as water at a pressure below atmospheric pressure. In the evaporator, the water whose temperature has decreased due to boiling evaporation is pumped out by a circulation pump, sent to a cooling location via a conduit, and then returns to the inside of the evaporator again via the conduit.

  When a refrigerant such as water is used, it is necessary to compress a large amount of refrigerant vapor generated in an evaporation mechanism that evaporates the refrigerant under a reduced pressure lower than the atmospheric pressure at a high compression ratio. Therefore, the evaporative cooling device of Patent Document 1 connects a centrifugal compressor and a roots compressor as a compressor in series, and further compresses the refrigerant vapor compressed by the centrifugal compressor with a roots compressor. Yes.

JP 2008-122012 A

  According to the refrigeration cycle apparatus described in Patent Document 1, no consideration is given to the state of the refrigerant returning to the evaporator. Therefore, the present invention provides a refrigeration cycle apparatus capable of extending the life of the compressor in consideration of the state of the refrigerant returning to the evaporation mechanism.

This disclosure
A main circuit for circulating a refrigerant whose saturation vapor pressure is negative at normal temperature, a compressor that compresses the refrigerant vapor, a condensation mechanism that condenses the refrigerant vapor, and an evaporation mechanism that stores the refrigerant liquid and evaporates the refrigerant liquid A main circuit in which the compressor, the condensing mechanism, and the evaporation mechanism are connected in this order;
It has an endothermic heat exchanger and a decompression mechanism, and the refrigerant liquid stored in the evaporation mechanism is supplied to the endothermic heat exchanger, and the internal pressure of the evaporation mechanism is absorbed by the endothermic heat exchanger. An evaporation side circulation circuit configured such that high-pressure refrigerant is decompressed by the decompression mechanism and returns to the evaporation mechanism;
There is provided a refrigeration cycle apparatus comprising: an obstruction structure that prevents liquid droplets in the refrigerant returned to the evaporation mechanism from the evaporation side circulation circuit from being guided to the compressor.

  According to the above-described refrigeration cycle apparatus, the droplets in the refrigerant that have been decompressed by the decompression mechanism and returned to the evaporation mechanism are prevented from being guided to the compressor by the obstruction structure. Thereby, the lifetime of a compressor can be extended.

Configuration diagram of a refrigeration cycle apparatus according to the present embodiment Sectional drawing which shows the evaporation mechanism and disturbance structure which concern on this embodiment Sectional drawing which shows the evaporation mechanism and disturbance structure which concern on this embodiment The perspective view which shows the disturbance structure which concerns on a 1st modification Sectional drawing which shows the disturbance structure which concerns on a 1st modification Sectional drawing which shows the 2nd modification which has an ejection prevention wall Sectional drawing which shows another form of a 2nd modification Sectional drawing which shows another form of a 2nd modification Sectional drawing which shows the 3rd modification which has a separation wall Sectional drawing which shows the 4th modification which has an ejection prevention structure Sectional drawing which shows another form of a 4th modification Sectional drawing which shows another form of a 4th modification Sectional drawing which shows another form of a 4th modification The block diagram which shows an example of the refrigerating-cycle apparatus which has a connection part shown in FIG. Sectional drawing which shows another form of a 4th modification Sectional drawing which shows another form of a 4th modification Sectional drawing which shows another form of a 4th modification Sectional drawing which shows the evaporation mechanism which concerns on a 5th modification Sectional drawing which shows another form of a 5th modification Sectional drawing which shows another form of a 5th modification Sectional drawing which shows the disturbance structure which concerns on a 6th modification Sectional drawing which shows another form of a 6th modification Sectional drawing which shows the 7th modification which has a baffle plate Sectional drawing which shows another form of a 7th modification Sectional drawing which shows another form of a 7th modification Sectional drawing which shows another form of a 7th modification Sectional view showing the ejector as the condensing mechanism

  In the refrigeration cycle apparatus described in Patent Document 1, the cooling portion is configured by, for example, a heat exchanger. In this case, when the refrigerant liquid inside the evaporator is pumped out by the supply pump and supplied to the heat exchanger that is the cooling place via the pipe line, the refrigerant liquid is inside the heat exchanger that is the cooling place. There is a possibility of evaporation. When the refrigerant liquid evaporates inside the heat exchanger that is the cooling location, it becomes difficult to supply the refrigerant liquid inside the evaporator to the heat exchanger by the supply pump. Therefore, it is conceivable to provide a decompression mechanism in the middle of the conduit for returning the refrigerant after passing through the cooling portion to the inside of the evaporator. Thereby, it can prevent that a refrigerant | coolant liquid evaporates in the heat exchanger which is a cooling location.

  The refrigerant decompressed by the decompression mechanism returns to the inside of the evaporator. At this time, droplets of refrigerant liquid may be generated. The droplets can be sucked into the compressor from inside the evaporator and the droplets can damage the compressor components. This shortens the life of the compressor. In particular, this problem becomes more serious when the evaporator is downsized due to a demand for downsizing or when the pipe line connecting the evaporator and the compressor is shortened.

The first aspect of the present disclosure is:
A main circuit for circulating a refrigerant whose saturation vapor pressure is negative at normal temperature, a compressor that compresses the refrigerant vapor, a condensation mechanism that condenses the refrigerant vapor, and an evaporation mechanism that stores the refrigerant liquid and evaporates the refrigerant liquid A main circuit in which the compressor, the condensing mechanism, and the evaporation mechanism are connected in this order;
It has an endothermic heat exchanger and a decompression mechanism, and the refrigerant liquid stored in the evaporation mechanism is supplied to the endothermic heat exchanger, and the internal pressure of the evaporation mechanism is absorbed by the endothermic heat exchanger. An evaporation side circulation circuit configured such that high-pressure refrigerant is decompressed by the decompression mechanism and returns to the evaporation mechanism;
There is provided a refrigeration cycle apparatus comprising: an obstruction structure that prevents liquid droplets in the refrigerant returned to the evaporation mechanism from the evaporation side circulation circuit from being guided to the compressor.

  According to a second aspect of the present disclosure, in addition to the first aspect, a refrigeration cycle apparatus in which the pressure reducing mechanism is a valve, a nozzle, or a capillary tube is provided.

  In the third aspect of the present disclosure, in addition to the first aspect or the second aspect, the obstruction structure returns the refrigerant that has absorbed heat in the heat absorption heat exchanger into the refrigerant liquid stored in the evaporation mechanism. A connecting portion of the evaporation side circulation circuit connected to the evaporation mechanism, and the connecting portion is arranged such that a tip of the connecting portion is located below a liquid surface of the refrigerant liquid stored in the evaporation mechanism. Provided is a refrigeration cycle apparatus that extends through a wall of an evaporation mechanism to an internal space of the evaporation mechanism. According to the third aspect, even if droplets are generated in the refrigerant returning to the evaporation mechanism, the droplets are taken into the refrigerant liquid stored in the evaporation mechanism, so that the droplets of the refrigerant liquid are guided to the compressor. It is prevented from being scraped.

  According to a fourth aspect of the present disclosure, in addition to the third aspect, the evaporation mechanism forms a columnar internal space, and the connection portion has a flow of the refrigerant returned from the evaporation side circulation circuit to the evaporation mechanism. Provided is a refrigeration cycle apparatus connected to the evaporation mechanism so as to have a velocity component in the circumferential direction of the internal space. According to the 4th aspect, the flow of the refrigerant | coolant which returned to the inside of the evaporator in the refrigerant | coolant liquid stored by the evaporation mechanism flows along the circumferential direction of the internal space of an evaporation mechanism. Accordingly, the refrigerant flows so as to rotate in the refrigerant liquid stored in the evaporation mechanism. Therefore, even if droplets are generated in the refrigerant returning to the evaporation mechanism due to the centrifugal force, the droplets of the refrigerant liquid and the refrigerant vapor in the refrigerant are separated. As a result, the refrigerant liquid droplets are prevented from being guided to the compressor.

  In the fifth aspect of the present disclosure, in addition to the third aspect or the fourth aspect, the refrigerant flow that is provided above the connection portion and returned from the evaporation side circulation circuit to the evaporation mechanism is supplied to the evaporation mechanism. Provided is a refrigeration cycle apparatus further comprising an ejection preventing wall that prevents ejection of the stored refrigerant liquid from the liquid level. According to the fifth aspect, since the flow of the refrigerant returned to the evaporation mechanism is prevented from being ejected from the liquid level of the refrigerant liquid stored in the evaporation mechanism, the liquid level of the refrigerant liquid stored in the evaporation mechanism is reduced. It is disturbed and the refrigerant liquid droplet is prevented from being guided to the compressor.

  According to a sixth aspect of the present disclosure, in addition to any one of the third aspect to the fifth aspect, an outlet for supplying the refrigerant liquid stored in the evaporation mechanism to the evaporation side circulation circuit; Provided is a refrigeration cycle apparatus further comprising a separation wall provided inside the evaporation mechanism between a return port formed by a connecting portion and for returning the refrigerant to the evaporation mechanism. According to the sixth aspect, the refrigerant vapor returned to the evaporation mechanism through the return port is prevented from flowing out to the evaporation side circulation circuit through the outflow port.

The seventh aspect of the present disclosure includes, in addition to the third aspect,
The connection portion extends through the wall of the evaporation mechanism so as not to exceed the liquid level of the refrigerant liquid stored in the evaporation mechanism in the internal space of the evaporation mechanism,
The connection portion includes an ejection preventing structure for preventing the flow of the refrigerant returned from the evaporation side circulation circuit to the evaporation mechanism from being ejected from the liquid level of the refrigerant liquid stored in the evaporation mechanism. A refrigeration cycle apparatus is provided.

  According to the seventh aspect, the jet preventing structure prevents the refrigerant flow that has passed through the connecting portion and returned to the evaporation mechanism from being ejected from the liquid level of the refrigerant liquid stored in the evaporation mechanism. As a result, the liquid level of the refrigerant liquid stored in the evaporation mechanism is disturbed, and the refrigerant liquid droplets are prevented from being guided to the compressor.

  According to an eighth aspect of the present disclosure, in addition to the seventh aspect, the ejection preventing structure is positioned above a bottom portion of the evaporation mechanism, and a flow in which a cross-sectional area expands along a flow direction of the refrigerant flowing through the connection portion. Provided is a refrigeration cycle apparatus including an enlarged portion that forms a path. According to the eighth aspect, since the refrigerant flowing through the connection portion in the flow path formed by the enlarged portion is decelerated, the refrigerant flow returned from the connection portion to the evaporation mechanism is ejected from the liquid surface of the refrigerant liquid stored in the evaporation mechanism. Is prevented.

  In a ninth aspect of the present disclosure, in addition to the eighth aspect, the connection portion extends upward from the enlarged portion, and forms a flow path having a constant cross-sectional area along the flow direction of the refrigerant flowing through the connection portion. Provided is a refrigeration cycle apparatus further including an extending portion. According to the ninth aspect, the size of the bubbles formed by the refrigerant vapor contained in the refrigerant flowing through the connecting portion can be adjusted in the flow path formed by the extension. This prevents the bubbles from being supplied to the evaporation side circulation circuit after returning to the evaporation mechanism.

The tenth aspect of the present disclosure includes, in addition to the eighth aspect and the ninth aspect,
The ejection preventing structure is further provided with a flow dividing plate that is provided so as to overlap the central axis of the connecting portion and has a plurality of through holes,
The plurality of through holes provide a refrigeration cycle apparatus having an opening area larger than a cross-sectional area of a flow path formed by the connecting portion upstream of the enlarged portion in a flow direction of the refrigerant flowing through the connecting portion. To do.

  According to the 10th aspect, it can suppress by the shunt plate that the flow rate of the refrigerant | coolant which returns to an evaporation mechanism from a connection part varies spatially. In addition, since the opening areas of the plurality of through holes are larger than the cross-sectional area of the flow path formed by the connection portion upstream of the enlarged portion, the flow of the refrigerant passing through the plurality of through holes is too fast. Can be prevented.

  In an eleventh aspect of the present disclosure, in addition to any one of the eighth to tenth aspects, the ejection preventing structure further includes a porous member provided to overlap the central axis of the connection portion. A refrigeration cycle apparatus is provided. According to the eleventh aspect, the enlarged portion and the porous member can suppress the flow rate of the refrigerant from returning spatially while decelerating the flow of the refrigerant returning from the connection portion to the evaporation mechanism.

  In a twelfth aspect of the present disclosure, in addition to any one of the eighth to tenth aspects, the ejection prevention structure protrudes so as to squeeze in a direction opposite to a flow direction of the refrigerant flowing through the connection portion, Provided is a refrigeration cycle apparatus further comprising a constricted portion having a tip overlapping the central axis of the connecting portion. According to the twelfth aspect, the refrigerant flow can be evenly divided by the constricted portion. Further, since the separation (reduction of vortex) of the refrigerant is suppressed in the refrigerant flow, the pressure loss of the refrigerant flow is small.

  A thirteenth aspect of the present disclosure provides the refrigeration cycle apparatus, in addition to any one of the seventh aspect to the twelfth aspect, wherein the connection portion extends vertically upward. According to the thirteenth aspect, the flow of the refrigerant is decelerated by the gravity acting on the refrigerant flowing through the connecting portion.

The fourteenth aspect of the present disclosure includes, in addition to the ninth aspect,
The pressure reducing mechanism is a valve;
An endothermic temperature sensor for detecting the temperature of the refrigerant returning to the evaporation mechanism that has absorbed heat by the endothermic heat exchanger;
A refrigerant vapor temperature sensor for detecting the temperature of the refrigerant vapor in the evaporation mechanism;
A liquid level sensor for detecting the liquid level of the refrigerant liquid stored in the evaporation mechanism;
Based on the detected value of the endothermic temperature sensor, the detected value of the refrigerant vapor temperature sensor, and the detected value of the liquid level sensor, the opening of the valve is adjusted to adjust the refrigerant liquid stored in the evaporation mechanism. There is provided a refrigeration cycle apparatus further comprising a control unit for controlling a liquid level.

  According to the fourteenth aspect, on the basis of the temperature of the refrigerant returning to the evaporation mechanism that has absorbed heat by the heat exchanger for heat absorption, the temperature of the refrigerant vapor in the evaporation mechanism, and the liquid level of the refrigerant liquid stored in the evaporation mechanism, The liquid level of the stored refrigerant liquid can be controlled to an appropriate liquid level. For example, the liquid level of the refrigerant liquid stored in the evaporation mechanism can be controlled so that bubbles due to the refrigerant vapor are generated above the upper end of the enlarged portion. That is, the liquid level of the refrigerant liquid stored in the evaporation mechanism can be controlled so that the refrigerant flows in a single-phase flow (liquid phase flow) state up to the upper end of the enlarged portion.

  In a fifteenth aspect of the present disclosure, in addition to the third aspect, the evaporation mechanism has an internal space that is narrowed toward a bottom portion of the evaporation mechanism, and the connection portion is connected to a bottom portion of the evaporation mechanism. A refrigeration cycle apparatus is provided. According to the fifteenth aspect, the refrigerant flow returned to the evaporation mechanism from the connection portion is decelerated in the internal space of the evaporation mechanism, so the refrigerant flow returned from the connection portion to the evaporation mechanism is stored in the evaporation mechanism. It is prevented that the liquid is ejected from the liquid surface.

  According to a sixteenth aspect of the present disclosure, in addition to the fifteenth aspect, the sixteenth aspect further includes a flow dividing plate provided in the internal space so as to overlap a central axis of the connection portion, and having a plurality of through holes. Provided is a refrigeration cycle apparatus having an opening area larger than a cross-sectional area of a flow path formed by the connecting portion. According to the sixteenth aspect, in the internal space of the evaporation mechanism, it is possible to suppress the flow rate of the refrigerant flow returning from the connection portion to the evaporation mechanism from being spatially varied by the flow dividing plate. Moreover, since the opening area of a some through-hole is larger than the cross-sectional area of the flow path formed of the connection part, it can prevent that the flow of the refrigerant | coolant which passes a some through-hole becomes too quick.

  According to a seventeenth aspect of the present disclosure, in addition to the fifteenth aspect or the sixteenth aspect, a narrowed portion that protrudes toward the bottom of the evaporation mechanism in the internal space and has a tip that overlaps the central axis of the connection portion. Further provided is a refrigeration cycle apparatus. According to the seventeenth aspect, in the internal space of the evaporation mechanism, the flow of the refrigerant that has returned from the connection portion to the evaporation mechanism can be evenly divided by the constricted portion. Further, in this refrigerant flow, since the separation of the refrigerant (generation of vortex) is suppressed, the pressure loss of the refrigerant flow is small.

  An eighteenth aspect of the present disclosure provides the refrigeration cycle apparatus, in addition to any one of the fifteenth aspect to the seventeenth aspect, wherein the connection portion extends vertically upward. According to the eighteenth aspect, the flow of the refrigerant is decelerated by the gravity acting on the refrigerant flowing through the connecting portion.

  A nineteenth aspect of the present disclosure is the first aspect or the second aspect according to the first aspect or the second aspect, in which the obstruction structure is provided in the evaporation mechanism so as to return the refrigerant to the evaporation mechanism above the liquid level of the refrigerant liquid stored in the evaporation mechanism. A refrigeration unit connected to the evaporation side circulation circuit, the connection unit connected to the evaporation mechanism so that the refrigerant flow immediately after returning to the evaporation mechanism includes a velocity component in a vertical direction. A cycle device is provided. According to the nineteenth aspect, the droplets of the refrigerant liquid contained in the refrigerant returned to the evaporation mechanism flow toward the liquid surface of the refrigerant liquid stored in the evaporation mechanism, and thus are included in the refrigerant returned to the evaporation mechanism. The refrigerant liquid droplets are prevented from being guided to the compressor.

  According to a twentieth aspect of the present disclosure, in the first aspect or the second aspect, the obstruction structure may be arranged in the evaporation mechanism so that the refrigerant is returned to the evaporation mechanism above the liquid level of the refrigerant liquid stored in the evaporation mechanism. There is provided a refrigeration cycle apparatus comprising: a connection portion of the evaporation side circulation circuit connected; and a baffle plate for preventing a flow of refrigerant returned to the evaporation mechanism via the connection portion. According to the twentieth aspect, the baffle plate prevents the refrigerant liquid droplets contained in the refrigerant returned to the evaporation mechanism from being guided to the compressor.

  Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. The following description relates to an example of the present invention, and the present invention is not limited to these.

<This embodiment>
As shown in FIG. 1, the refrigeration cycle apparatus 1 includes a main circuit 10, a condensation side circulation circuit 20, and an evaporation side circulation circuit 30. The main circuit 10 includes a compressor 3, a condensation mechanism 4, and an evaporation mechanism 2, and the compressor 3, the condensation mechanism 4, and the evaporation mechanism 2 are connected in this order. The evaporation mechanism 2 and the compressor 3 are connected by a flow path 5a. The compressor 3 and the condensation mechanism 4 are connected by a flow path 5b. The condensation mechanism 4 and the evaporation mechanism 2 are connected by a flow path 5c. The main circuit 10, the condensation side circulation circuit 20, and the evaporation side circulation circuit 30 are filled with a refrigerant and are in a negative pressure state lower than the atmospheric pressure. The saturated vapor pressure of the refrigerant at room temperature (Japanese Industrial Standard: 20 ° C. ± 15 ° C./JIS Z8703) is a negative pressure. A refrigerant | coolant is a refrigerant | coolant which has water or alcohol as a main component, for example. The main circuit 10 circulates a refrigerant whose saturation vapor pressure at room temperature is negative.

  The compressor 3 compresses the refrigerant vapor. The compressed refrigerant vapor is supplied to the condensing mechanism 4 through the flow path 5b. The compressor 3 is typically an axial flow or centrifugal turbo compressor. In the case where the compressor 3 is a turbo compressor, when the droplets are sucked into the compressor 3, the droplets collide with the impeller and damage the impeller.

  The condensing mechanism 4 condenses the refrigerant vapor and stores the refrigerant liquid. The refrigerant liquid condensed by the condensation mechanism 4 is supplied to the evaporation mechanism 2 via the flow path 5c. The evaporation mechanism 2 stores the refrigerant liquid and evaporates the refrigerant liquid. The refrigerant vapor evaporated by the evaporation mechanism 2 is supplied to the compressor 3 via the flow path 5a.

  The condensation side circulation circuit 20 includes a pump 6 and a heat exchanger 7 for heat dissipation. A part of the refrigerant liquid stored in the condensing mechanism 4 is supplied to the heat dissipation heat exchanger 7 by the pump 6. The condensation mechanism 4 is formed by, for example, a hollow container having heat insulating properties and pressure resistance. The heat dissipation heat exchanger 7 is, for example, a finned tube heat exchanger that exchanges heat between the refrigerant liquid and outdoor air. In the heat dissipation heat exchanger 7, for example, the refrigerant liquid radiates heat by exchanging heat with outdoor air. The refrigerant liquid radiated in the heat radiating heat exchanger 7 is returned to the inside of the condensing mechanism 4. Refrigerant vapor compressed by the compressor 3 is supplied to the condensing mechanism 4 via the flow path 5b. The refrigerant liquid returned to the condensation mechanism 4 from the condensation side circulation circuit 20 cools and condenses the refrigerant vapor supplied via the flow path 5b. The refrigerant liquid whose temperature has increased by condensing the refrigerant vapor is supplied to the heat dissipation heat exchanger 7 by the pump 6, and again dissipates heat in the heat dissipation heat exchanger 7. A part of the refrigerant liquid stored in the condensing mechanism 4 is supplied to the evaporation mechanism 2 through the flow path 5c.

  The evaporation side circulation circuit 30 includes a pump 8, an endothermic heat exchanger 9, and a pressure reducing mechanism 12. The evaporation side circulation circuit 30 is configured such that the refrigerant liquid stored in the evaporation mechanism 2 is supplied to the heat absorption heat exchanger 9. The evaporation side circulation circuit 30 is configured such that refrigerant having a pressure higher than the pressure inside the evaporation mechanism 2 that has absorbed heat by the heat absorption heat exchanger 9 is reduced in pressure by the pressure reduction mechanism 12 and returned to the evaporation mechanism 2. Specifically, the evaporation mechanism 2 and the pump 8 are connected by a flow path 30a. The pump 8 and the heat absorption heat exchanger 9 are connected by a flow path 30b. The heat absorption heat exchanger 9 and the evaporation mechanism 2 are connected by a flow path 30c. A decompression mechanism 12 is provided in the middle of the flow path 30c. The decompression mechanism 12 is, for example, a valve, a nozzle, or a capillary tube. The valve as the pressure reducing mechanism 12 is, for example, an electric valve whose opening degree can be adjusted. The nozzle as the decompression mechanism 12 is, for example, a throttle nozzle. As the decompression mechanism 12, a pipe such as a capillary tube may be used.

The refrigerant liquid stored in the evaporation mechanism 2 whose temperature has decreased as a result of evaporation of the refrigerant liquid in the evaporation mechanism 2 is supplied to the heat absorption heat exchanger 9 by the pump 8. The evaporation mechanism 2 is formed by, for example, a hollow container having heat insulating properties and pressure resistance. The heat-absorbing heat exchanger 9 is, for example, a finned tube heat exchanger that exchanges heat between the refrigerant liquid and indoor air. The refrigerant liquid supplied to the heat absorption heat exchanger 9 absorbs heat by exchanging heat with indoor air. That is, the refrigeration cycle apparatus 1 is configured as an air conditioner that performs indoor cooling. The refrigerant liquid supplied to the heat absorption heat exchanger 9 becomes a refrigerant having a higher pressure than the inside of the evaporation mechanism 2 by the pump 8. The refrigerant liquid that has passed through the heat absorption heat exchanger 9 is decompressed by the decompression mechanism 12. In some cases, the decompressed refrigerant returns to the evaporation mechanism 2 while containing droplets of the refrigerant liquid.

  As shown in FIG. 2A, the refrigeration cycle apparatus 1 includes a blocking structure 35 that prevents droplets in the refrigerant that have returned from the evaporation side circulation circuit 30 to the evaporation mechanism 2 from being guided to the compressor 3. The obstruction structure 35 is a connection part 34a of the evaporation side circulation circuit 30 connected to the evaporation mechanism 2 so as to return the refrigerant absorbed by the heat absorption heat exchanger 9 into the refrigerant liquid stored in the evaporation mechanism 2. A return port 36 for returning the refrigerant to the evaporation mechanism 2 is formed by the connecting portion 34a. Specifically, the return port 36 opens to the internal space of the evaporation mechanism 2 below the liquid level of the refrigerant liquid stored in the evaporation mechanism 2. Note that, as shown in FIG. 2B, the tip of the connection portion 34 a may extend to the internal space of the evaporation mechanism 2. In this case, the return port 36 opens to the internal space of the evaporation mechanism 2 below the liquid level of the refrigerant liquid stored in the evaporation mechanism 2. That is, the connection part 34 a extends through the wall of the evaporation mechanism 2 to the internal space of the evaporation mechanism 2 so that the tip of the connection part 34 a is located below the liquid level of the refrigerant liquid stored in the evaporation mechanism 2. ing. In this case, it is possible to suppress supply of the bubbles to the evaporation side circulation circuit 30 after the bubbles formed by the refrigerant vapor contained in the refrigerant flowing through the connection portion 34 a are returned to the inside of the evaporation mechanism 2. As a result, it is possible to prevent bubbles from being contained in the refrigerant flowing inside the heat absorption heat exchanger 9, so that the heat exchange efficiency of the heat absorption heat exchanger 9 and the efficiency (COP: coefficient of performance) of the refrigeration cycle apparatus 1 can be reduced. Can be improved. Such a knowledge is that the efficiency of the refrigeration cycle apparatus 1 configured to return the refrigerant absorbed by the heat absorption heat exchanger 9 to the refrigerant liquid stored in the evaporation mechanism 2 is the refrigerant absorbed by the heat absorption heat exchanger. This is based on the fact that the present inventors have found that the efficiency is lower than the efficiency of the refrigeration cycle apparatus configured to return the refrigerant to the level above the liquid level of the refrigerant liquid stored in the evaporation mechanism. Such knowledge is a novel knowledge that has not existed before.

  The evaporation mechanism 2 forms a columnar internal space, for example. In the present embodiment, the evaporation mechanism 2 forms a cylindrical internal space. The upper and lower sides of the internal space of the evaporation mechanism 2 may be formed by a dome-shaped wall surface. The connection part 34 a is connected to the bottom part of the pressure vessel of the evaporation mechanism 2. The connection part 34a forms a part of the flow path 30c. A pipe 32 that forms a flow path 30 a is connected to the bottom surface of the evaporation mechanism 2. By connecting the pipe 32 to the evaporation mechanism 2, an outlet 33 for supplying the refrigerant liquid stored in the evaporation mechanism 2 to the evaporation side circulation circuit 30 is formed. Further, a pipe 50 that forms a flow path 5 c is connected to a side surface portion close to the bottom surface of the evaporation mechanism 2. A pipe 70 that forms a flow path 5 a is connected to the wall surface of the evaporation mechanism 2 above the liquid level of the refrigerant liquid stored in the evaporation mechanism 2. In the present embodiment, the pipe 70 is connected to the upper surface portion of the evaporation mechanism 2. The pipe 70 may be connected to the side surface of the evaporation mechanism 2. For example, when the opening on the evaporation mechanism 2 side of the flow path 5a and the return port 36 are viewed in plan, the opening on the evaporation mechanism 2 side of the flow path 5a is opposite to the return port 36 across the central axis of the internal space of the evaporation mechanism 2. Located on the side.

  The connection part 34 a is connected to the bottom surface of the evaporation mechanism 2. As a result, the refrigerant that has absorbed heat in the heat absorption heat exchanger 9 is returned to the refrigerant liquid stored in the evaporation mechanism 2. When the refrigerant flowing through the connection portion 34a includes droplets, the refrigerant liquid returned to the evaporation mechanism 2 through the connection portion 34a comes into contact with the refrigerant liquid stored in the evaporation mechanism 2, so that the droplets of the refrigerant liquid are formed. It is taken in by the stored refrigerant liquid. For this reason, it is possible to prevent the refrigerant liquid droplets from being sucked into the compressor 3 through the flow path 5a. On the other hand, when the refrigerant flowing in the connection portion 34a contains refrigerant vapor, the refrigerant vapor passes through the refrigerant liquid stored in the evaporation mechanism 2 and is sucked into the compressor 3 via the flow path 5a. It is. The connecting portion 34 a is connected to the evaporation mechanism 2 so as to be orthogonal to the bottom surface of the inner peripheral surface of the evaporation mechanism 2. The connecting portion 34 a may be connected to the evaporation mechanism 2 in a state of being inclined with respect to the bottom surface on the inner peripheral surface of the evaporation mechanism 2. The connecting portion 34a may be connected to the side surface portion of the evaporation mechanism 2. In this case, the connection part 34a may be orthogonal to the side surface on the inner peripheral surface of the evaporation mechanism 2 or may be inclined.

  The distance between the liquid level of the refrigerant liquid stored in the evaporation mechanism 2 and the return port 36 is such that the momentum of the refrigerant returned to the evaporation mechanism 2 through the connecting portion 34a on the liquid level of the refrigerant liquid stored in the evaporation mechanism 2. It is desirable that the value is determined so that the value is sufficiently reduced.

  The distance between the outlet 33 and the return port 36 is, for example, 10 mm or more. In this case, the refrigerant vapor contained in the refrigerant that has returned to the evaporation mechanism 2 through the connection portion 34 a is unlikely to flow out through the outlet 33. As a result, the refrigerant vapor can be prevented from flowing into the pump 8, and the ability of the pump 8 to supply the refrigerant liquid is reliably exhibited.

  The refrigeration cycle apparatus 1 switches between the cooling operation and the heating operation of the refrigeration cycle apparatus 1 by connecting, for example, an outdoor heat exchanger and an indoor heat exchanger to the evaporation mechanism 2 and the condensation mechanism 4 via a four-way valve. It can also be configured as a possible air conditioner. When the refrigeration cycle apparatus 1 performs a cooling operation, the outdoor heat exchanger functions as the heat dissipation heat exchanger 7, and the indoor heat exchanger functions as the heat absorption heat exchanger 9. On the other hand, when the refrigeration cycle apparatus 1 performs the heating operation, the outdoor heat exchanger functions as the heat absorption heat exchanger 9 and the indoor heat exchanger functions as the heat dissipation heat exchanger 7. Moreover, the refrigeration cycle apparatus 1 does not need to be configured as an air conditioner, and may be a chiller, for example. In the heat dissipation heat exchanger 7 and the heat absorption heat exchanger 9, the refrigerant may exchange heat with a gas or liquid other than air. The specifications of the heat-dissipating heat exchanger 7 and the heat-absorbing heat exchanger 9 are not particularly limited as long as they are indirect.

<Modification>
The above embodiment can be modified from various viewpoints. A modification of the above embodiment will be described. The following modifications are configured in the same manner as in the present embodiment unless otherwise specified. Components that are the same as or correspond to those of the present embodiment are denoted by the same reference numerals, and descriptions thereof may be omitted. In the following modifications, the same or corresponding components are denoted by the same reference numerals, and redundant description may be omitted.

(First modification)
As shown in FIG. 3, for example, the obstruction structure 35 may be a connection portion 34 b connected to the side surface portion of the evaporation mechanism 2. The connecting portion 34b is connected to the evaporation mechanism 2 so that the refrigerant flow returned from the evaporation side circulation circuit 30 to the evaporation mechanism 2 has a velocity component in the circumferential direction of the internal space. Specifically, the connection part 34 b is connected to the evaporation mechanism 2 so that the central axis of the flow path formed by the connection part 34 b does not intersect the central axis of the internal space of the evaporation mechanism 2. Thereby, as shown in FIG. 4, the refrigerant that has returned to the evaporation mechanism 2 through the connection portion 34 b flows so as to rotate along the circumferential direction of the internal space of the evaporation mechanism 2. Therefore, when the refrigerant returned to the evaporation mechanism 2 through the connecting portion 34b contains refrigerant droplets, the refrigerant droplets easily collect on the outer peripheral side of the internal space of the evaporation mechanism 2 due to centrifugal force. It becomes easy for steam to collect on the central axis side of the internal space of the evaporation mechanism 2. As a result, the refrigerant liquid droplets are prevented from being guided to the compressor 3. 3 and 4, the z-axis negative direction is the vertical direction, and the xy plane is a plane orthogonal to the z-axis.

  As long as the refrigerant flow returned from the evaporation side circulation circuit 30 to the evaporation mechanism 2 has a velocity component in the circumferential direction of the internal space, the connection portion 34 b may be connected to the bottom surface portion of the evaporation mechanism 2. In this case, the refrigerant that has returned to the evaporation mechanism 2 through the connection portion 34b can be caused to flow so as to rotate or spirally move along the circumferential direction of the internal space. Thereby, the refrigerant returned to the evaporation mechanism 2 can be kept in the refrigerant liquid stored in the evaporation mechanism 2 for a long period of time. Thereby, when the refrigerant | coolant droplet is contained in the refrigerant | coolant which returned to the evaporation mechanism 2 through the connection part 34b, the droplet of refrigerant | coolant liquid is isolate | separated and the droplet of refrigerant | coolant liquid is guide | induced to the compressor 3. Is disturbed.

(Second modification)
As shown in FIG. 5A, the refrigeration cycle apparatus 1 may further include an ejection prevention wall 37 provided above the connection portion 34a. In this case, the connecting portion 34 a is connected to the evaporation mechanism 2 so that the refrigerant flows upward or obliquely upward inside the evaporation mechanism 2. The ejection preventing wall 37 prevents the refrigerant flow returned to the evaporation mechanism 2 from the evaporation side circulation circuit 30 from being ejected from the liquid level of the refrigerant liquid stored in the evaporation mechanism 2. Specifically, the ejection preventing wall 37 is provided inside the evaporation mechanism 2 and is located below the liquid level of the refrigerant liquid inside the evaporation mechanism 2. The refrigerant flow that has returned to the evaporation mechanism 2 through the connecting portion 34a collides with the ejection preventing wall 37 and decelerates. Thereby, it can prevent that the refrigerant | coolant which returned to the evaporation mechanism 2 through the connection part 34a ejects from the liquid level of a refrigerant liquid. Even when the distance between the liquid level of the refrigerant liquid stored in the evaporation mechanism 2 and the return port 36 is short, it is possible to prevent the refrigerant from being returned to the evaporation mechanism 2 through the connecting portion 34a, so that the evaporation mechanism 2 can be downsized. Can also be planned.

  The ejection preventing wall 37 is provided, for example, so as to form an angle of 90 ° with respect to the flow of the refrigerant that has returned to the evaporation mechanism 2 through the connection portion 34a. However, the attachment angle of the ejection preventing wall 37 is not particularly limited as long as the refrigerant flow returned to the evaporation mechanism 2 through the connection portion 34a collides with the ejection preventing wall 37. The ejection preventing wall 37 may be formed in a shape having a flat surface or a curved surface, or a shape having a plurality of through holes. A plurality of ejection preventing walls 37 may be provided. As long as the refrigerant flow returned to the evaporation mechanism 2 through the connection portion 34a collides with the ejection prevention wall 37, the number and shape thereof are not particularly limited. When the ejection preventing wall 37 and the return port 36 are viewed in plan, for example, the entire return port 36 overlaps the ejection preventing wall 37. Thereby, said effect can be acquired more reliably. For example, the ejection preventing wall 37 is provided so as to be positioned on the ejection preventing wall 37 on a line obtained by extending the axis of the connecting portion 34 a to the internal space of the evaporation mechanism 2. Thereby, said effect can be acquired more reliably. As shown in FIG. 5B, the connecting portion 34 a may extend through the wall of the evaporation mechanism 2 to a position below the ejection preventing wall 37 in the internal space of the evaporation mechanism 2.

  Moreover, as shown in FIG. 5C, the shape of the ejection preventing wall 37 may be a hemispherical shape having a plurality of through holes 37h (orifices). In this case, the ejection preventing wall 37 is provided in the internal space of the evaporation mechanism 2 so as to cover the return port 36 above the connection portion 34a. The plurality of through holes 37h are formed so as to be distributed over substantially the entire ejection preventing wall 37. The plurality of through holes 37h are formed, for example, so as to include a plurality of groups of a plurality of through holes arranged in an annular shape at the same height. Further, the sum of the opening areas of the plurality of through holes 37h is larger than the cross-sectional area of the flow path formed by the connecting portion 34a. The refrigerant flow that has returned to the evaporation mechanism 2 through the connecting portion 34a collides with the ejection preventing wall 37 and decelerates. As a result, the refrigerant flow returned to the evaporation mechanism 2 from the evaporation side circulation circuit 30 is prevented from being ejected from the liquid surface of the refrigerant liquid stored in the evaporation mechanism 2. Further, since the refrigerant flows so as to pass through the plurality of through holes 37h, the flow of the refrigerant can be diverted radially as shown in FIG. 5C.

(Third Modification)
As shown in FIG. 6, the refrigeration cycle apparatus 1 may further include a separation wall 39 provided inside the evaporation mechanism 2 between the outlet 33 and the return port 36. For example, the separation wall 39 is located on a line segment connecting the outflow port 33 and the return port 36 with the shortest distance. The separation wall 39 prevents the refrigerant vapor contained in the refrigerant that has returned to the evaporation mechanism 2 through the return port 36 from flowing out from the outflow port 33. Preventing the refrigerant vapor from flowing out from the outlet 33 by the separation wall 39 is particularly advantageous when the outlet 33 and the return port 36 are not sufficiently separated. For this reason, the evaporation mechanism 2 can be reduced in size.

  For example, the separation wall 39 is provided on the bottom surface of the evaporation mechanism 2 at an angle of 90 ° with respect to the liquid surface of the evaporation mechanism 2. However, the posture and position where the separation wall 39 is provided are not particularly limited as long as the refrigerant vapor contained in the refrigerant returned to the evaporation mechanism 2 is prevented from flowing out from the outlet 33. The separation wall 39 may be formed in a shape having a flat surface or a curved surface. A plurality of separation walls 39 may be provided. That is, the shape and number of the separation walls 39 are not particularly limited as long as the refrigerant vapor contained in the refrigerant returned to the evaporation mechanism 2 through the return port 36 is prevented from flowing out from the outlet port 33. Further, the separation wall 39 may have a network structure. In this case, the liquid droplets of the refrigerant liquid can be captured by a network structure.

(Fourth modification)
As shown in FIG. 7, the connecting portion 34 a may extend through the wall of the evaporation mechanism 2 so as not to exceed the liquid level of the refrigerant liquid stored in the evaporation mechanism 2 in the internal space of the evaporation mechanism 2. . In this case, the connection part 34 a is an ejection prevention structure for preventing the refrigerant flow returned from the evaporation side circulation circuit 30 to the evaporation mechanism 2 from being ejected from the liquid level of the refrigerant liquid stored in the evaporation mechanism 2. 38. By providing the connection part 34a with the ejection prevention structure 38, the flow of the refrigerant that has passed through the connection part 34a and returned to the evaporation mechanism 2 is prevented from being ejected from the liquid level of the refrigerant liquid stored in the evaporation mechanism 2. The Thereby, the liquid level of the refrigerant liquid stored in the evaporation mechanism 2 is disturbed, and the refrigerant liquid droplets are prevented from being guided to the compressor. For example, the connecting portion 34 a extends through the wall of the generating mechanism 2 to a position below the liquid level of the refrigerant liquid stored in the evaporation mechanism 2 in the internal space of the evaporation mechanism 2. The connecting portion 34a extends vertically upward.

  The ejection preventing structure 38 includes, for example, an enlarged portion 34g. The enlarged part 34g is located above the bottom part of the evaporation mechanism 2 and forms a flow path whose cross-sectional area is enlarged along the flow direction of the refrigerant flowing through the connection part 34a. Since the refrigerant flowing through the connecting portion 34a is decelerated in the flow path formed by the enlarged portion 34g, the refrigerant flow returned from the connecting portion 34a to the evaporation mechanism 2 is ejected from the liquid surface of the refrigerant liquid stored in the evaporation mechanism 2. Is prevented. Thereby, the liquid level of the refrigerant liquid stored in the evaporation mechanism 2 is disturbed, and the refrigerant liquid droplets are prevented from being guided to the compressor.

  As shown in FIG. 8, the enlarged portion 34g may be formed such that the cross-sectional shape of the enlarged portion 34g along the central axis of the connecting portion 34a has a step. The enlarged portion 34g having such a shape can be manufactured, for example, by welding a plurality of pipes having different pipe inner diameters in accordance with Japanese Industrial Standards (JIS). The enlarged portion 34g may be formed so that the cross-sectional area at the downstream end of the flow path formed by the enlarged portion 34g is larger than the cross-sectional area at the upstream end of the flow path formed by the enlarged portion 34g. The enlarged part 34g may be formed so that, for example, a part of the wall of the enlarged part 34g is confined. Moreover, the piping 32 which forms the flow path 30a may be connected to the side wall of the evaporation mechanism 2 below the liquid level of the refrigerant liquid stored in the evaporation mechanism 2, as shown in FIG.

  As shown in FIG. 10, the connection part 34 a may further include an extension part 34 h. The extension part 34h extends upward from the enlarged part 34g and forms a flow path having a constant cross-sectional area along the flow direction of the refrigerant flowing through the connection part 34a. In this flow path, the size of bubbles formed by the refrigerant vapor contained in the refrigerant flowing through the connecting portion 34a is adjusted. This prevents the bubbles from being supplied to the evaporation side circulation circuit 30 after returning to the evaporation mechanism 2. For this reason, it can prevent that a refrigerant | coolant vapor | steam flows in into the pump 8, and the capability in which the pump 8 supplies a refrigerant | coolant liquid is exhibited reliably. In this case, the refrigeration cycle apparatus 1 may be configured as shown in FIG.

  The refrigeration cycle apparatus 1 shown in FIG. 11 further includes a heat absorption side temperature sensor 16, a refrigerant vapor temperature sensor 17, a liquid level sensor 18, and a control unit 15, and the connection part 34a is configured as shown in FIG. Other than that, the configuration is the same as that of the refrigeration cycle apparatus 1 according to the present embodiment. The decompression mechanism 12 is a valve. The decompression mechanism 12 is an electric valve whose opening degree can be adjusted, for example. The heat absorption side temperature sensor 16 is a sensor for detecting the temperature of the refrigerant returning to the evaporation mechanism 2 that has absorbed heat by the heat absorption heat exchanger 9. The heat absorption side temperature sensor 16 is attached to, for example, a pipe that forms the evaporation circuit 30 on the downstream side of the heat absorption heat exchanger 9 in the refrigerant flow direction. The refrigerant vapor temperature sensor 17 is a sensor for detecting the temperature of the refrigerant vapor in the evaporation mechanism 2. For example, the refrigerant vapor temperature sensor 17 is attached to the wall surface of the evaporation mechanism 2 above the liquid level of the refrigerant liquid stored in the evaporation mechanism 2. The liquid level sensor 18 is a sensor for detecting the liquid level of the refrigerant liquid stored in the evaporation mechanism 2. The liquid level sensor 18 is, for example, a float type liquid level sensor, an optical type liquid level sensor, an ultrasonic type liquid level sensor, or a capacitance type liquid level sensor. The control unit 15 evaporates by adjusting the opening of the valve that is the decompression mechanism 12 based on the detection value of the heat absorption side temperature sensor 16, the detection value of the refrigerant vapor temperature sensor 17, and the detection value of the liquid level sensor 18. The liquid level of the refrigerant liquid stored in the mechanism 2 is controlled. Therefore, as shown in FIG. 11, the control unit 15 receives the detection values of the heat absorption side temperature sensor 16, the refrigerant vapor temperature sensor 17, and the liquid level sensor 18, so that the heat absorption side temperature sensor 16 and the refrigerant vapor temperature are received. The sensor 17 and the liquid level sensor 18 are connected. Further, the control unit 15 is connected to the pressure reducing mechanism 12 so that a signal for adjusting the opening degree of the valve that is the pressure reducing mechanism 12 can be transmitted to the pressure reducing mechanism 12. Note that the connection between the control unit 15 and the heat absorption side temperature sensor 16, the refrigerant vapor temperature sensor 17, the liquid level sensor 18, and the decompression mechanism 12 may be either wired connection or wireless connection.

For example, the control unit 15 controls the liquid level of the refrigerant liquid stored in the evaporation mechanism 2 so that the refrigerant flowing through the connection unit 34a flows as a single-phase flow (liquid phase flow) up to the upper end of the expansion unit 34g. That is, the control unit 15 controls the liquid level of the refrigerant liquid stored in the evaporation mechanism 2 so that bubbles due to the refrigerant vapor are generated above the upper end of the enlarged part 34g. The control unit 15 acquires the detection value of the heat absorption side temperature sensor 16, the detection value of the refrigerant vapor temperature sensor 17, and the detection value of the liquid level sensor 18. The control unit 15 obtains the saturated vapor pressure Ph [Pa] of the refrigerant at the temperature detected by the heat absorption side temperature sensor 16 from the detection value of the heat absorption side temperature sensor 16. The control unit 15 obtains the saturated vapor pressure Ps [Pa] of the refrigerant at the temperature detected by the refrigerant vapor temperature sensor 17 from the detection value of the refrigerant vapor temperature sensor 17. Here, the density of the refrigerant liquid stored in the evaporation mechanism is ρ [kg / m ³ ], the acceleration of gravity is g [m / s ² ], and the liquid of the refrigerant liquid stored in the evaporation mechanism 2 from the upper end of the enlarged portion 34g. The height to the surface is defined as h [m]. In order for the refrigerant flowing through the connecting portion 34a to flow as a single-phase flow (liquid phase flow) up to the upper end of the enlarged portion 34g, the relationship of Ph-Ps ≦ ρgh needs to be satisfied. The controller 15 controls the liquid level of the refrigerant liquid stored in the evaporation mechanism 2 by adjusting the opening of the valve that is the decompression mechanism 12 so that this relationship is satisfied.

  As shown in FIG. 12, the ejection preventing structure 38 may further include a flow dividing plate 34i in addition to the enlarged portion 34g. The flow dividing plate 34i is provided so as to overlap the central axis of the connecting portion 34a, and has a plurality of through holes 34j. It is possible to suppress the flow rate of the refrigerant returning to the evaporation mechanism 2 through the connection portion 34a from being spatially varied by the flow dividing plate 34i. The flow dividing plate 34i is formed so that the outer peripheral end of the flow dividing plate 34i is connected to the inner peripheral surface of the enlarged portion 34g. The plurality of through holes 34j have an opening area larger than the cross-sectional area of the flow path formed by the connecting portion 34a on the upstream side of the enlarged portion 34g in the flow direction of the refrigerant flowing through the connecting portion 34a. That is, the sum total of the opening areas of the plurality of flow paths 34j is larger than the cross-sectional area of the flow path formed by the connection part 34a on the upstream side of the enlarged part 34g. For this reason, it can prevent that the flow of the refrigerant | coolant which passes the some through-hole 34j becomes too quick. Note that one flow dividing plate 34i may be provided along the flow direction of the connecting portion 34a, or two or more flow dividing plates 34i may be provided.

  As shown in FIG. 13, the ejection preventing structure 38 may further include a porous member 34k in addition to the enlarged portion 34g. The porous member 34k is provided so as to overlap the central axis of the connecting portion 34a. Thereby, while the expansion part 34g and the porous member 34k can decelerate the flow of the refrigerant returning to the evaporation mechanism 2 from the connection part 34a, it is possible to suppress the spatial variation in the flow velocity, and the bubbles contained in the refrigerant are liquid. It is possible to prevent pressure fluctuation from occurring inside the evaporation mechanism 2 by rupturing on the surface. That is, in the ejection preventing structure 38 shown in FIG. 12, the bubbles included in the refrigerant are trapped in the flow dividing plate 34i, and a large-sized bubble is formed. There is a possibility that the pressure inside the evaporation mechanism 2 fluctuates due to the bubbles rising toward the liquid level and bursting at the liquid level. On the other hand, in the ejection preventing structure 38 shown in FIG. 13, the outer peripheral end of the porous member 34k is connected to the inner peripheral surface of the enlarged portion 34g. For this reason, the size of the bubbles contained in the refrigerant is reduced by passing through the porous member 34k. Thereby, it can suppress that the bubble of a large size is formed and the pressure inside the evaporation mechanism 2 fluctuates. The porous member 34k is made of, for example, a urethane foam, a metal-based porous material, or a sponge made of melamine resin. The porous member 34k may be a plate-like member having a plurality of holes such as punching metal, for example.

  As shown in FIG. 14, the ejection preventing structure 38 may further include a constricted portion 34m in addition to the enlarged portion 34g. The constricted portion 34m projects so as to constrict in the direction opposite to the flow direction of the refrigerant flowing through the connecting portion 34a. The narrowed portion 34m has a tip that overlaps the central axis of the connecting portion 34a. Thereby, the flow of the refrigerant can be evenly divided by the constricted portion 34m. Further, since the separation (reduction of vortex) of the refrigerant is suppressed in the refrigerant flow, the pressure loss of the refrigerant flow is small.

(5th modification)
As shown in FIG. 15, the evaporation mechanism 2 may have an internal space that is constricted toward the bottom of the evaporation mechanism 2. In this case, the connecting portion 34 a is connected to the bottom of the evaporation mechanism 2. The connecting portion 34a extends vertically upward. Since the refrigerant flow returned to the evaporation mechanism 2 through the connection portion 34a decelerates in the internal space of the evaporation mechanism 2, the refrigerant flow returned to the evaporation mechanism 2 through the connection portion 34a is stored in the evaporation mechanism 2. It is prevented that the refrigerant liquid is ejected from the liquid surface.

  In this case, the refrigeration cycle apparatus 1 may further include a flow dividing plate 31g as shown in FIG. The flow dividing plate 31g is provided in the internal space so as to overlap the central axis of the connecting portion 34a. Further, the flow dividing plate 31g has a plurality of through holes 31h. The plurality of through holes 31h have an opening area larger than the cross-sectional area of the flow path formed by the connection portion 34a. Thereby, in the internal space of the evaporation mechanism 2, it can suppress by the flow dividing plate 31g that the flow velocity of the flow of the refrigerant | coolant which returned to the evaporation mechanism 2 from the connection part 34a spatially varies. Moreover, since the opening area of the some through-hole 31h is larger than the cross-sectional area of the flow path formed of the connection part 34a, it can prevent that the flow of the refrigerant | coolant which passes the several through-hole 31h becomes too fast. Note that one flow dividing plate 31g may be provided along the flow direction of the connecting portion 34a, or two or more flow dividing plates 31g may be provided.

  Furthermore, the refrigeration cycle apparatus 1 may further include a constricted portion 31i as shown in FIG. The constricted portion 31i protrudes toward the bottom of the evaporation mechanism 2 in the internal space of the evaporation mechanism 2, and has a tip that overlaps the central axis of the connection portion 34a. Thereby, in the internal space of the evaporation mechanism 2, the flow of the refrigerant returned to the evaporation mechanism 2 from the connection portion 34a can be evenly divided by the constricted portion 31i. Further, in this refrigerant flow, since the separation of the refrigerant (generation of vortex) is suppressed, the pressure loss of the refrigerant flow is small.

(Sixth Modification)
As shown in FIG. 18, the obstruction structure 35 is connected to the evaporation side circulation circuit 30 connected to the evaporation mechanism 2 so as to return the refrigerant to the evaporation mechanism 2 above the liquid level of the refrigerant liquid stored in the evaporation mechanism 2. It may be part 34c. The connecting portion 34c is connected to the evaporation mechanism 2 so that the refrigerant flow immediately after being returned to the evaporation mechanism 2 includes a velocity component in the vertical direction. Specifically, the connection portion 34 c extends along the vertical direction and is connected to the upper surface portion of the evaporation mechanism 2. For this reason, the velocity component of the refrigerant flow immediately after being returned to the evaporation mechanism 2 is predominantly the velocity component in the vertical direction. Thereby, the flow of the refrigerant returned to the evaporation mechanism 2 proceeds toward the liquid level of the refrigerant liquid stored in the evaporation mechanism 2. Thereby, the droplets of the refrigerant liquid contained in the refrigerant returned to the evaporation mechanism 2 easily reach the liquid level of the refrigerant liquid stored in the evaporation mechanism 2. As a result, the refrigerant liquid droplets are prevented from being guided to the compressor 3.

  As long as the flow of the refrigerant immediately after returning to the evaporation mechanism 2 includes a velocity component in the vertical direction, the connection portion 34c may be connected to the evaporation mechanism 2 obliquely downward as shown in FIG. Also in this case, the flow of the refrigerant returned to the evaporation mechanism 2 proceeds toward the liquid level of the refrigerant liquid stored in the evaporation mechanism 2. The droplets of the refrigerant liquid easily reach the liquid level of the refrigerant liquid stored in the evaporation mechanism 2. This prevents the refrigerant liquid droplets from being guided to the compressor 3.

(Seventh Modification)
As shown in FIG. 20, the blocking structure 35 may include a connection portion 34 d of the evaporation side circulation circuit 30 and a baffle plate 40. The connection portion 34 d is connected to the evaporation mechanism 2 so as to return the refrigerant to the evaporation mechanism 2 above the liquid level of the refrigerant liquid stored in the evaporation mechanism 2. The connection portion 34d is connected to the side surface portion of the evaporation mechanism 2. The connecting portion 34d may be provided on the upper surface portion of the evaporation mechanism 2. The baffle plate 40 is a member for obstructing the flow of the refrigerant returned to the evaporation mechanism 2 via the connection portion 34d. The baffle plate 40 is provided on the upper surface portion of the evaporation mechanism 2 in the internal space of the evaporation mechanism 2, for example. When the flow of the refrigerant returned to the evaporation mechanism 2 via the connection portion 34 d comes into contact with the baffle plate 40, the refrigerant liquid droplets adhere to the baffle plate 40. Alternatively, the baffle plate 40 changes the direction of the flow of the refrigerant containing the liquid droplets of the refrigerant so that the flow of the refrigerant containing the liquid droplets of the refrigerant goes to the liquid level of the refrigerant liquid stored in the evaporation mechanism 2. This prevents the refrigerant liquid droplets from being guided to the compressor 3.

  As shown in FIG. 21, the baffle plate 40 may be provided on the side surface of the evaporation mechanism 2 above the return port 36 and in the internal space of the evaporation mechanism 2. In addition, the baffle plate 40 may be provided between the return port 36 and the opening of the evaporation mechanism 2 in the flow path 5 a in the internal space of the evaporation mechanism 2. Specifically, the baffle plate 40 is preferably located on a line segment connecting the return port 36 and the opening of the flow path 5a on the evaporation mechanism 2 side at the shortest distance. The baffle plate 40 can be configured, for example, as a plate including a flat surface or a curved surface, a plate including a bent portion, or a plate having a network structure. A plurality of baffle plates 40 may be provided in the internal space of the evaporation mechanism 2. The baffle plate 40 desirably extends downward in the internal space of the evaporation mechanism 2. As shown in FIG. 22, the baffle plate 40 may be immersed in a refrigerant liquid stored in the evaporation mechanism 2.

  As shown in FIG. 23, the connecting portion 34 d may extend through the wall of the evaporation mechanism 2 to a position above the liquid level of the refrigerant liquid stored in the evaporation mechanism 2. The return port 36 is located above the liquid level of the refrigerant liquid stored in the evaporation mechanism 2. Further, the baffle plate 40 is located above the return port 36. When the baffle plate 40 and the return port 36 are viewed in plan from the baffle plate 40 side, the entire return port 36 overlaps the baffle plate 40. When the refrigerant spouted upward from the return port 36 contacts the baffle plate 40, the liquid droplets of the refrigerant liquid adhere to the baffle plate 40. Alternatively, the baffle plate 40 changes the direction of the flow of the refrigerant containing the liquid droplets of the refrigerant so that the flow of the refrigerant containing the liquid droplets of the refrigerant goes to the liquid level of the refrigerant liquid stored in the evaporation mechanism 2. This prevents the refrigerant liquid droplets from being guided to the compressor 3.

(Other variations)
In the present embodiment, the refrigeration cycle apparatus 1 may be provided with a plurality of compressors between the evaporation mechanism 2 and the condensation mechanism 4. In this case, the upstream compressor may be a turbo compressor, and the downstream compressor may be a positive displacement compressor. Further, the refrigeration cycle apparatus may include a cooler for cooling the refrigerant vapor compressed by the upstream compressor in the middle of the path connecting the upstream compressor and the downstream compressor. Good.

  The refrigeration cycle apparatus 1 may include a pressure reducing mechanism such as a pressure reducing valve in the flow path 5c.

As the condensation mechanism 4, an ejector 60 as shown in FIG. 24 may be used instead of the hollow container shown in FIG. The ejector 60 mixes the refrigerant vapor and refrigerant liquid compressed by the compressor to condense the refrigerant vapor. The ejector 60 includes a first nozzle 61, a second nozzle 62, a mixing unit 63, a diffuser unit 64, a needle valve 65, and an actuator 66. The refrigerant liquid that has flowed out of the heat dissipation heat exchanger 7 through the pipe 67 is supplied to the first nozzle 61 as a driving flow. The refrigerant vapor compressed by the compression mechanism 3 is supplied to the second nozzle 62 through the flow path 5b. By injecting the refrigerant liquid from the first nozzle 61, the pressure of the mixing unit 63 becomes lower than the pressure of the flow path 5b. As a result, the refrigerant vapor is continuously sucked into the second nozzle 62 through the flow path 5b. The refrigerant liquid injected while accelerating from the first nozzle 61 and the refrigerant vapor injected while expanding and accelerating from the second nozzle 62 are mixed in the mixing unit 63. And due to the temperature difference between the refrigerant liquid and the refrigerant vapor, the pressure increase effect based on the transport of energy between the refrigerant liquid and the refrigerant vapor and the momentum transport between the refrigerant liquid and the refrigerant vapor, Refrigerant vapor condenses. The diffuser unit 64 recovers the static pressure by decelerating the flow of the refrigerant.

  The flow rate of the refrigerant liquid as the driving flow can be adjusted by the needle valve 65 and the actuator 66. The sectional area of the orifice at the tip of the first nozzle 61 can be changed by the needle valve 65. The position of the needle valve 65 is adjusted by the actuator 66. Thereby, the flow volume of the refrigerant liquid flowing through the first nozzle 61 can be adjusted.

  The refrigeration cycle apparatus 1 is configured such that the return port 36 opens to the internal space of the evaporation mechanism 2 below the liquid level of the refrigerant liquid stored in the evaporation mechanism 2 and returns to the evaporation mechanism 2 through the return port 36. There may be further provided a structure for preventing the refrigerant vapor contained in the gas from flowing out from the outlet 33. Such a structure is, for example, a net-like structure provided around the outflow port 33. Such a structure may be, for example, a structure provided around the outflow port 33 and having a plurality of through holes.

  The refrigeration cycle apparatus according to the present invention is particularly advantageous, for example, as a home air conditioner or a commercial air conditioner. Moreover, the refrigerating cycle apparatus which concerns on this invention can be utilized as a chiller or a heat pump, for example.

DESCRIPTION OF SYMBOLS 1 Refrigeration cycle apparatus 2 Evaporation mechanism 3 Compressor 4 Condensing mechanism 9 Heat absorption heat exchanger 10 Main circuit 12 Decompression mechanism 15 Control part 16 Endothermic temperature sensor 17 Refrigerant vapor temperature sensor 18 Liquid level sensor 30 Evaporation side circulation circuit 31g Dividing plate 31h Through-hole 31i Constriction part 33 Outflow port 34a-34d Connection part 34g Expansion part 34h Extension part 34i Split plate 34j Through-hole 34k Porous member 34m Constriction part 35 Blocking structure 36 Return port 37 Ejection prevention wall 38 Ejection prevention structure 39 Separation wall 40 baffle plate

Claims (2)

A main circuit for circulating a refrigerant whose saturation vapor pressure is negative at normal temperature, a compressor that compresses the refrigerant vapor, a condensation mechanism that condenses the refrigerant vapor, and an evaporation mechanism that stores the refrigerant liquid and evaporates the refrigerant liquid A main circuit in which the compressor, the condensing mechanism, and the evaporation mechanism are connected in this order;
A pump and a nozzle are provided, and the refrigerant liquid stored in the evaporation mechanism is pressurized by the pump, and then depressurized by the nozzle to return above the liquid level of the refrigerant liquid stored in the evaporation mechanism. An evaporation side circulation circuit,
E Bei and a baffle plate that prevents the droplets in the refrigerant returned from the evaporator-side circulation circuit to the vaporization mechanism is led to the compressor,
The baffle plate is disposed so as to come into contact with the refrigerant flow returned to the evaporation mechanism,
The baffle plate extends downward in the internal space of the evaporation mechanism,
Refrigeration cycle equipment. A main circuit that circulates a refrigerant having a negative saturated vapor pressure at room temperature, a compressor that compresses the refrigerant vapor, a condensation mechanism that condenses the refrigerant vapor, and an evaporation mechanism that stores the refrigerant liquid and evaporates the refrigerant liquid A main circuit in which the compressor, the condensing mechanism, and the evaporation mechanism are connected in this order;
A pump and a nozzle are provided, and the refrigerant liquid stored in the evaporation mechanism is pressurized by the pump, and then depressurized by the nozzle to return above the liquid level of the refrigerant liquid stored in the evaporation mechanism. An evaporation side circulation circuit,
A baffle plate that prevents liquid droplets in the refrigerant returned to the evaporation mechanism from the evaporation side circulation circuit from being guided to the compressor,
The baffle plate is disposed so as to come into contact with the refrigerant flow returned to the evaporation mechanism,
When the evaporation mechanism is viewed in plan, the opening on the evaporation mechanism side of the flow path connecting the evaporation mechanism and the compressor is located on the evaporation side circulation circuit with the central axis of the internal space of the evaporation mechanism interposed therebetween. Located on the opposite side to where the refrigerant is returned,
Refrigeration cycle equipment.

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