Ejector

Abstract

To provide an ejector which can easily change a suction flow rate.SOLUTION: An ejector comprises: a casing having a base part in which a suction fluid is supplied to an inside introduction space, a tapered part connected to the introduction space, and forming a tapered space which is gradually contracted in a diameter toward one side in an axial line direction, and a mixing pipe which forms a mixing space extending from the tapered space to one side in the axial line direction; a drive flow nozzle extending with an axial line as a center, inserted into the introduction space from the other side in the axial line direction, and located in the tapered space at its tip opening which injects a drive fluid; and a moving mechanism for making a position of the tip opening in the axial line direction variable within a range of a position of the tapered space in the axial line direction.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present disclosure relates to an ejector. [Background technology]

[0002] For example, Patent Document 1 discloses an ejector applied to a refrigeration cycle using a mixed refrigerant. This ejector has a nozzle that converts the pressure energy of high-pressure refrigerant flowing out from a condenser into velocity energy to reduce the pressure and expand the refrigerant, and a pressure-boosting section that uses a high-speed refrigerant flow ejected from the nozzle to draw in the gas-phase refrigerant evaporated in the evaporator. The pressure-boosting section converts velocity energy into pressure energy while mixing the refrigerant ejected from the nozzle with the refrigerant drawn from the evaporator, thereby increasing the pressure of the refrigerant. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 3433737 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the ejector described in Patent Document 1, the flow of refrigerant is determined by three pressures: the supplied high-pressure refrigerant, the suctioned refrigerant, and the pressure booster section where these refrigerants are mixed. Therefore, it is difficult to vary the suction flow rate within a fixed cycle.

[0005] The present disclosure has been made to solve the above-mentioned problems, and has an object to provide an ejector that can easily change the suction flow rate. [Means for solving the problem]

[0006] In order to solve the above-described problems, an ejector according to the present disclosure includes a casing having a base portion through which a suction fluid is supplied to an internal introduction space, a tapered portion connected to the introduction space and forming a tapered space whose diameter gradually decreases toward one side in an axial direction, and a mixing tube forming a mixing space extending from the tapered space toward the one side in the axial direction; a driving flow nozzle extending about the axis and inserted into the introduction space from the other side in the axial direction, the driving flow nozzle having a tip opening from which a driving fluid is ejected located within the tapered space; and a movement mechanism for varying the axial position of the tip opening within a range of axial positions of the tapered space, The driving flow nozzle has a large diameter pipe provided on the other axial side and a small diameter pipe provided on one axial side and having a diameter smaller than that of the large diameter pipe, the tip opening is formed at the end of the small diameter pipe on the one axial side, the outer peripheral surface of the small diameter pipe is arranged along the axial direction in a cross section along the axial direction, and only the small diameter pipe is movable in the tapered space. In order to solve the above-mentioned problems, an ejector according to the present disclosure includes a casing having a base portion through which a suction fluid is supplied to an internal introduction space, a tapered portion connected to the introduction space and forming a tapered space whose diameter gradually decreases toward one axial side, and a mixing tube forming a mixing space extending from the tapered space toward the one axial side; a drive flow nozzle extending about the axis and inserted into the introduction space from the other axial side, the tip opening from which a driving fluid is ejected being located within the tapered space; and a movement mechanism for varying the axial position of the tip opening within a range of axial positions of the tapered space, the movement mechanism extending only the one axial side of the drive flow nozzle including the tip opening in the axial direction to vary the axial position of the tip opening. . In order to solve the above-described problems, the ejector according to the present disclosure includes a casing having a base portion through which a suction fluid is supplied to an inner introduction space, a tapered portion connected to the introduction space and forming a tapered space whose diameter gradually decreases toward one axial side, and a mixing tube forming a mixing space extending from the tapered space to the one axial side; a driving flow nozzle extending about the axis and inserted into the introduction space from the other axial side, the tip opening from which the driving fluid is ejected being located in the tapered space; and a movement mechanism for adjusting the axial position of the tip opening within a range of axial positions of the tapered space. The casing further includes an outer casing that covers the base from the outside and forms a pre-introduction space between itself and the base, and through which the suction fluid is supplied to the pre-introduction space. A communication portion is formed around the entire periphery of a side wall of the base, connecting the introduction space and the pre-introduction space. [Effects of the Invention]

[0007] According to the ejector of the present disclosure, the suction flow rate can be easily changed. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic diagram of a refrigeration cycle of a turbo chiller according to a first embodiment of the present disclosure. [Figure 2] FIG. 1 is a perspective view of an ejector according to a first embodiment of the present disclosure. [Figure 3] FIG. 2 is a cross-sectional view of the ejector according to the first embodiment of the present disclosure. [Figure 4] FIG. 2 is a perspective view showing a tip opening of the motive flow nozzle according to the first embodiment of the present disclosure. [Figure 5] FIG. 10 is a cross-sectional view of an ejector according to a second embodiment of the present disclosure. [Figure 6] FIG. 10 is a perspective view of an ejector according to a third embodiment of the present disclosure. [Figure 7] FIG. 10 is a cross-sectional view of an ejector according to a third embodiment of the present disclosure. [Figure 8] FIG. 11 is a perspective view of an ejector according to a modified example of the third embodiment of the present disclosure. [Figure 9] FIG. 10 is a cross-sectional view of an ejector according to a modified example of the third embodiment of the present disclosure. [Figure 10] FIG. 10 is a cross-sectional view of an ejector according to a fourth embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0009] First Embodiment (turbo refrigerator) A turbo chiller 1 equipped with an ejector 10 according to an embodiment of the present disclosure will be described below with reference to FIGS. 1 to 4. FIG. A turbo chiller 1 is a cooling device that uses a turbo compressor such as a centrifugal compressor. The turbo chiller 1 is used, for example, in air conditioning systems in large-scale facilities such as office buildings. Figure 1 shows an example of the refrigeration cycle of the turbo chiller 1.

[0010] As shown in FIG. 1, the turbo chiller 1 includes a compressor 2, a condenser 3, an expansion valve 4, an evaporator 5, and an ejector 10.

[0011] The compressor 2 compresses the gaseous refrigerant W to increase the pressure of the refrigerant W. The condenser 3 cools the refrigerant W compressed by the compressor 2 and condenses it into a liquid. The expansion valve 4 depressurizes the refrigerant W from the condenser 3. The evaporator 5 evaporates the liquid refrigerant W depressurized by the expansion valve 4 and exchanges heat with outside air. The outside air is cooled by exchanging heat with the evaporator 5 and becomes cold air. The cold air produced by the evaporator 5 is sent into the room to be cooled. The refrigerant W evaporated in the evaporator 5 and turned into a gas is sent back to the compressor 2. In this way, the refrigerant W circulates within the refrigeration cycle of the turbo chiller 1. The refrigerant W may be, for example, a chlorofluorocarbon gas or a chlorofluorocarbon substitute.

[0012] In the following, the flow direction of the refrigerant W in the refrigeration cycle may be referred to simply as the "flow direction," the upstream side of the flow direction may be referred to simply as the "upstream," and the downstream side of the "flow direction" may be referred to simply as the "downstream."

[0013] The evaporator 5 of this embodiment is a liquid film evaporator. Therefore, unevaporated liquid refrigerant W is stored in the bottom of the evaporator 5. In order to recirculate the refrigerant W stored in the bottom of the evaporator 5, an ejector 10 is provided.

[0014] (ejector) The ejector 10 is connected to the downstream side of the condenser 3 by a driving flow pipe 6. A portion of the refrigerant W liquefied in the condenser 3 is supplied to the ejector 10 via the driving flow pipe 6. The ejector 10 is also connected to the bottom of the evaporator 5 by a suction flow pipe 7. The liquid refrigerant W stored in the bottom of the evaporator 5 is supplied to the ejector 10 via the suction flow pipe 7. Inside the ejector 10, the refrigerant W supplied via the driving flow pipe 6 and the refrigerant W supplied via the suction flow pipe 7 are mixed. The ejector 10 is also connected to the upstream side of the evaporator 5 by a return pipe 8. The ejector 10 returns the refrigerant W supplied via the driving flow pipe 6 and the suction flow pipe 7 to the evaporator 5 via the return pipe 8.

[0015] Next, the structure of the ejector 10 will be described in detail. In the following description, the refrigerant W supplied to the ejector 10 via the driving flow piping 6 may be referred to as the "driving fluid W1," the refrigerant W supplied to the ejector 10 via the suction flow piping 7 may be referred to as the "suction fluid W2," and the fluid generated by mixing the driving fluid W1 and the suction fluid W2 in the ejector 10 may be referred to as the "mixed fluid W3." In this embodiment, the driving fluid W1, the suction fluid W2, and the mixed fluid W3 are all liquids. The ejector 10 is a device that uses the pressure difference between the upstream side and the downstream side to suck in the suction fluid W2 and send it to the downstream side.

[0016] As shown in FIGS. 2 and 3, the ejector 10 includes a casing 20, a driving flow nozzle 30, a sealing mechanism 40, and a moving mechanism 50.

[0017] (Casing) The casing 20 is formed in a cylindrical shape that extends in one direction. In the following description, the axis O of the casing 20 may be simply referred to as the "axis O." Furthermore, the extending direction of the axis O may be simply referred to as the "axis O direction," the radial direction of the axis O may be simply referred to as the "radial direction," and the circumferential direction of the axis O may be simply referred to as the "circumferential direction." Furthermore, in the direction of the axis O, the downstream side may be referred to as the "one side in the direction of the axis O," and the upstream side may be referred to as the "other side in the direction of the axis O." The casing 20 has a base section 21 , a tapered section 22 , a mixing tube 23 , and a diffuser section 24 .

[0018] (base) The base 21 is formed in a cylindrical shape extending in the direction of the axis O. An introduction space V1 is formed inside the base 21. A suction fluid W2 is supplied to the introduction space V1 inside the base 21. The base 21 has a side wall 25 formed around the axis O and a bottom 26 provided on the other side of the side wall 25 in the direction of the axis O.

[0019] A suction hole 27 is formed in the side wall 25. In this embodiment, one suction hole 27 is formed in the side wall 25. The suction hole 27 penetrates the side wall 25 in the radial direction. The suction hole 27 is formed to have a circular cross section. A downstream end of the suction flow piping 7 (the end opposite the evaporator 5) is connected to the suction hole 27. The suction fluid W2 is supplied from the suction flow piping 7 through the suction hole 27 to the introduction space V1.

[0020] The bottom portion 26 closes the other side of the side wall 25 in the direction of the axis O. The bottom portion 26 is formed in a circular plate shape that is perpendicular to the axis O. An insertion hole 28 is formed in the center of the bottom portion 26. The insertion hole 28 is provided in the center of the bottom portion 26. The insertion hole 28 penetrates the bottom portion 26 in the direction of the axis O.

[0021] (Tapered part) The tapered portion 22 is provided at one end of the base portion 21 in the direction of the axis O. The tapered portion 22 is formed in a cylindrical shape extending in the direction of the axis O. The tapered portion 22 is arranged coaxially with the base portion 21. The tapered portion 22 is formed in a tapered shape that gradually reduces in diameter toward one side in the direction of the axis O. A tapered space V2 is formed inside the tapered portion 22. The tapered space V2 is connected to the introduction space V1 and gradually reduces in diameter toward one side in the direction of the axis O.

[0022] (mixing tube) The mixing tube 23 is provided at one end of the tapered section 22 in the direction of the axis O. The mixing tube 23 is formed in a cylindrical shape extending in the direction of the axis O. The mixing tube 23 is arranged coaxially with the tapered section 22. A mixing space V3 is formed inside the mixing tube 23. The mixing space V3 extends from the tapered space V2 to one side in the direction of the axis O.

[0023] (Diffuser section) The diffuser section 24 is provided at one end of the mixing tube 23 in the direction of the axis O. The diffuser section 24 is formed in a cylindrical shape extending in the direction of the axis O. The diffuser section 24 is arranged coaxially with the mixing tube 23. A diffuser space V4 is formed inside the diffuser section 24. The diffuser space V4 is connected to the mixing space V3 and gradually increases in diameter toward one side in the direction of the axis O.

[0024] (Driven flow nozzle) The drive flow nozzle 30 is formed in a cylindrical shape extending about the axis O. That is, the drive flow nozzle 30 is arranged coaxially with the casing 20. The drive flow nozzle 30 is inserted into the introduction space V1 from the other side in the direction of the axis O. The drive flow nozzle 30 has a large-diameter pipe 31, a connecting pipe 32, and a small-diameter pipe 33.

[0025] (large diameter pipe) The large diameter pipe 31 is provided on the other side of the driving flow nozzle 30 in the direction of the axis O. The large diameter pipe 31 is inserted into an insertion hole 28 provided in the bottom 26 of the casing 20. The large diameter pipe 31 is a cylindrical member extending in the direction of the axis O. The other end of the large diameter pipe 31 in the direction of the axis O is located outside the introduction space V1. The other end of the large diameter pipe 31 in the direction of the axis O is connected to the downstream end of the driving flow piping 6 (the end opposite the condenser 3). Driving fluid W1 is supplied into the large diameter pipe 31 from the driving flow piping 6.

[0026] (Connecting pipe) The connecting pipe 32 is provided at one end of the large diameter pipe 31 in the direction of the axis O. The connecting pipe 32 is formed in a cylindrical shape extending from the large diameter pipe 31 to one side in the direction of the axis O. The connecting pipe 32 is arranged coaxially with the large diameter pipe 31. The connecting pipe 32 is formed in a tapered shape that gradually reduces in diameter toward one side in the direction of the axis O.

[0027] (Small diameter pipe) The small diameter pipe 33 is provided on one side of the motive flow nozzle 30 in the direction of the axis O. More specifically, the small diameter pipe 33 is provided at the end of the connecting pipe 32 on one side in the direction of the axis O. The small diameter pipe 33 is formed in a cylindrical shape extending from the connecting pipe 32 on one side in the direction of the axis O. The small diameter pipe 33 is arranged coaxially with the connecting pipe 32. The small diameter pipe 33 is formed with a smaller diameter than the large diameter pipe 31. The small diameter pipe 33 has a tip opening 34 at the end on one side in the direction of the axis O.

[0028] (Tip opening) The tip opening 34 ejects the driving fluid W1 supplied into the driving flow nozzle 30. The tip opening 34 is located within the tapered space V2. The cross section of the tip opening 34 perpendicular to the axis O is circular.

[0029] (Sealing mechanism) The sealing mechanism 40 is disposed in the insertion hole 28 provided in the bottom 26 of the casing 20. The sealing mechanism 40 is provided between the insertion hole 28 and the driving flow nozzle 30. The sealing mechanism 40 supports the driving flow nozzle 30 so that it can move in the direction of the axis O. Furthermore, the sealing mechanism 40 seals between the casing 20 and the driving flow nozzle 30, preventing the refrigerant W from leaking from the introduction space V1. In this embodiment, the sealing mechanism 40 is provided around the entire circumference of the large diameter pipe 31 of the driving flow nozzle 30.

[0030] (moving mechanism) The movement mechanism 50 changes the position of the tip opening 34 of the driving flow nozzle 30 along the axis O within the range of the tapered space V2 along the axis O. In other words, the range of movement of the tip opening 34 is within the tapered space V2. In this embodiment, the movement mechanism 50 moves the entire driving flow nozzle 30 along the axis O to change the position of the tip opening 34 along the axis O. An example of the movement mechanism 50 is an electric mechanism using a ball screw or the like.

[0031] (Ejector suction mechanism) Next, the suction mechanism of the ejector 10 will be described. The pressure upstream of the drive flow nozzle 30 (toward the condenser 3) is higher than that downstream of the drive flow nozzle 30. This pressure difference causes the driving fluid W1 to flow into the drive flow nozzle 30 from the upstream side. The driving fluid W1 contracts in the tapered connecting pipe 32 of the drive flow nozzle 30. This reduces the pressure of the driving fluid W1 and directs it into the mixing space V3. This converts the pressure energy (expansion energy) of the driving fluid W1 into velocity energy, causing the driving fluid W1 to jet out of the tip opening 34 at high speed.

[0032] The driving fluid W1 ejected from the tip opening 34 draws in the refrigerant W stored at the bottom of the evaporator 5. The refrigerant W drawn from the evaporator 5 becomes the suction fluid W2. The suction fluid W2 flows through the suction flow piping 7 into the introduction space V1 in the casing 20. The suction fluid W2 is further drawn to one side (downstream) in the direction of the axis O by the driving fluid W1. As a result, the suction fluid W2 is guided from the introduction space V1 through the tapered space V2 to the mixing space V3.

[0033] In the mixing space V3, the driving fluid W1 and the suction fluid W2 are mixed and flow downstream. The mixing of the driving fluid W1 and the suction fluid W2 generates a mixed fluid W3. The mixed fluid W3 is guided from the mixing space V3 to the diffuser space V4.

[0034] In the diffuser space V4, the mixed fluid W3 flows downstream while being diffused. This increases the pressure of the mixed fluid W3. The mixed fluid W3 pressurized in the diffuser space V4 is sent from the ejector 10 to the downstream side (the evaporator 5 side).

[0035] (Action and effect) The effects of the ejector 10 of this embodiment will be described below. In this embodiment, the tip opening 34 of the driving flow nozzle 30 that ejects the driving fluid W1 is located within the tapered space V2. The movement mechanism 50 changes the position of the tip opening 34 along the axis O within the range of the position of the tapered space V2 along the axis O.

[0036] The suction fluid W2 is drawn into the introduction space V1 by the flow of the driving fluid W1. Therefore, as shown in FIG. 4, the suction flow rate is determined by the area ratio (Ams / Amd) of the flow path cross section Ams of the suction fluid W2 to the flow path cross section Amd of the driving fluid W1 at the axial O position of the tip opening 34. At the axial O position of the tip opening 34, the flow path cross section Amd of the driving fluid W1 is a cross section of the inner space of the tip opening 34, and the flow path cross section Ams of the suction fluid W2 is a portion of the cross section of the tapered space V2 excluding the cross section of the inner space of the tip opening 34. According to this embodiment, the ejector 10 can change the axial O position of the tip opening 34 within the tapered space V2. This allows the area ratio (Ams / Amd) of the flow path cross section Ams of the suction fluid W2 to the flow path cross section Amd of the driving fluid W1 to be changed by changing only the flow path cross section Ams of the suction fluid W2 at the axial O position of the tip opening 34. In this way, the area ratio (Ams / Amd) and the suction flow rate can be changed simply by changing the position of the tip opening 34. Therefore, by using the ejector 10, the suction flow rate can be easily changed.

[0037] Changing the suction flow rate can enable partial load operation and load following operation of the turbo chiller 1. For example, during partial load operation, the pressure of the driving fluid W1 is lower than that at rated pressure, reducing the flow rate of the driving fluid W1. In this case, the flow rate of the suction fluid W2 generally also decreases. However, when used to circulate refrigerant in a liquid film evaporator, it is desirable to circulate a constant flow rate, so the ratio of the flow rate of the suction fluid W2 to the flow rate of the driving fluid W1 must be increased. In this case, with the ejector 10 of this embodiment, the position of the tip opening 34 of the drive flow nozzle 30 in the axial direction O can be adjusted to expand the flow path cross-section Ams of the suction fluid W2, thereby increasing the ratio of the flow rate of the suction fluid W2 to the flow rate of the driving fluid W1.

[0038] In this embodiment, the movement mechanism 50 moves the entire motive flow nozzle 30 in the direction of the axis O, thereby varying the position of the tip opening 34 in the direction of the axis O.

[0039] According to the present embodiment, the moving mechanism 50 can change the position of the tip opening 34 in the direction of the axis O with a simple configuration. Therefore, the production efficiency of the ejector 10 can be improved and the manufacturing cost of the ejector 10 can be reduced.

[0040] In this embodiment, the casing 20 has a diffuser portion 24 that is connected to the mixing space V3 and forms a diffuser space V4 whose diameter gradually increases toward one side in the direction of the axis O.

[0041] According to the present embodiment, the ejector 10 can diffuse and expand the fluids mixed in the mixing tube 23 in the diffuser portion 24. This allows the ejector 10 to increase the pressure of the mixed fluid W3 in the diffuser portion 24 and then send it downstream.

[0042] Furthermore, in this embodiment, the ejector 10 draws the refrigerant W from the evaporator 5 and recirculates it within the refrigeration cycle. However, if a pump is used to circulate the refrigerant, for example, the moving parts of the pump must be frequently maintained, resulting in high maintenance costs. Circulating liquid refrigerant within a cycle without using a pump has not been previously known. In contrast, the ejector 10 draws the liquid refrigerant W by utilizing the pressure difference within the cycle and circulates it within the cycle. This eliminates the need to use a pump to circulate the liquid refrigerant W. This eliminates the need for pump maintenance costs, enabling costs to be reduced. Furthermore, the frequency of maintenance of the turbo chiller 1 as a whole can be reduced.

[0043] In the first embodiment, the case where the motive flow nozzle 30 is moved has been described, but the present invention is not limited to this. It is sufficient that the motive flow nozzle 30 and the casing 20 move relatively in the direction of the axis O. For example, the movement mechanism 50 may be connected to the casing 20, and the casing 20 may be moved in the direction of the axis O.

[0044] Second Embodiment An ejector 210 according to a second embodiment of the present disclosure will be described below with reference to Fig. 5. Configurations similar to those in the first embodiment described above will be given the same names and reference numerals, and descriptions thereof will be omitted as appropriate.

[0045] As shown in FIG. 5, the small diameter tube 233 of the driving flow nozzle 230 is provided so as to be extendable and retractable in the direction of the axis O. Furthermore, the movement mechanism 250 of this embodiment extends and retracts only one side of the driving flow nozzle 230 along the axis O, including the tip opening 34, thereby varying the position of the tip opening 34 along the axis O. The movement mechanism 250 is connected to, for example, the small-diameter tube 33 of the driving flow nozzle 30, and includes an antenna 251 for receiving signals from an external source.

[0046] Furthermore, the ejector 210 has an operating device 260. The operating device 260 is installed, for example, outside the turbo chiller 1. A user operates the operating device 260 to send an operating signal to the antenna 251. When the antenna 251 receives the operating signal from the operating device 260, the movement mechanism 250 extends or retracts the small diameter pipe 233 in the direction of the axis O in accordance with the operating signal. This makes it possible to change the position of the tip opening 34 in the direction of the axis O.

[0047] In this embodiment, the movement mechanism 250 extends and retracts only one side of the motive flow nozzle 230 in the direction of the axis O, including the tip opening 34, to vary the position of the tip opening 34 in the direction of the axis O.

[0048] According to this embodiment, the movement mechanism 250 can change the position of the tip opening 34 in the direction of the axis O without moving the seal (seal mechanism 240) between the motive flow nozzle 230 and the casing 20. This makes it possible to more reliably prevent leakage of the suction fluid W2.

[0049] Third Embodiment An ejector 310 according to a third embodiment of the present disclosure will be described below with reference to Figures 6 and 7. Configurations similar to those in the first embodiment described above will be denoted by the same names and reference numerals, and descriptions thereof will be omitted as appropriate.

[0050] 6 and 7, the casing 320 further includes an outer casing 321 that covers the base 21 from the outside. The outer casing 321 is provided around the entire periphery of the casing 320. A pre-introduction space V5 is formed between the outer casing 321 and the base 21. The suction fluid W2 is supplied to the pre-introduction space V5 before being supplied to the introduction space V1.

[0051] The outer casing 321 is formed with a suction hole 322. The suction hole 322 penetrates the outer casing 321 in the radial direction.

[0052] A communication portion 323 that connects the introduction space V1 and the pre-introduction space V5 is formed around the entire circumference of the side wall 25 of the base 21 around the axis O. In this embodiment, the communication portion 323 is a slit 324 that extends in the circumferential direction. The slit 324 penetrates the side wall 25 of the base 21 in the radial direction. The slit 324 is formed in an annular shape without any gaps in the circumferential direction. The width dimension of the slit 324 in the direction of the axis O is constant regardless of the circumferential position.

[0053] In this embodiment, the casing 320 covers the base 21 from the outside to form a pre-introduction space V5 between the base 21 and the casing 320, and further includes an outer casing 321 through which the suction fluid W2 is supplied into the pre-introduction space V5. A communication portion 323 is formed around the entire periphery of the side wall 25 of the base 21, which connects the introduction space V1 and the pre-introduction space V5.

[0054] According to this embodiment, the suction fluid W2 is first introduced from the suction flow piping 7 into the pre-introduction space V5. The suction fluid W2 spreads throughout the entire circumferential direction within the pre-introduction space V5. The suction fluid W2 then flows into the introduction space V1 via the communication portion 323. In this manner, the ejector 310 of this embodiment can supply the suction fluid W2 from the entire periphery of the side wall 25 of the base 21 into the introduction space V1 via the communication portion 323. This allows the ejector 310 to uniformly distribute the suction fluid W2 in the circumferential direction.

[0055] In this embodiment, the communication portion 323 is a slit 324 extending in the circumferential direction of the axis O.

[0056] According to this embodiment, the communication portion 323 can be easily formed in the side wall 25 of the base portion 21. Therefore, the production efficiency of the ejector 310 can be improved.

[0057] Next, a modified example of the third embodiment will be described with reference to FIGS. As shown in Figures 8 and 9, the communication portion 323 may be a plurality of holes 325 arranged in a circumferential direction of the axis O. The holes 325 penetrate the side wall 25 of the base 21 in a radial direction. The plurality of holes 325 are arranged at equal intervals in the circumferential direction. The holes 325 are formed to have a circular cross section. All of the holes 325 are formed to have the same shape.

[0058] In this modification, the communication portions 323 are holes 325 arranged in the circumferential direction of the axis O.

[0059] According to this embodiment, the ejector 310 can make the flow rate distribution of the suction fluid W2 in the circumferential direction more uniform.

[0060] <Fourth embodiment> An ejector 410 according to a fourth embodiment of the present disclosure will be described below with reference to Fig. 10. Configurations similar to those in the first embodiment described above will be denoted by the same names and reference numerals, and descriptions thereof will be omitted as appropriate.

[0061] 10, the entire large diameter pipe 31 of the driving flow nozzle 430 is located on the other side of the base 21 in the direction of the axis O, and the small diameter pipe 433 of the driving flow nozzle 430 is inserted into the introduction space V1. In this embodiment, the middle portion of the small diameter pipe 433 in the direction of the axis O is located in the insertion hole 28 of the casing 20. The sealing mechanism 440 is provided around the entire circumference of the small diameter pipe 433.

[0062] In this embodiment, the entire large diameter pipe 31 is located on the other side in the direction of the axis O than the base portion 21. Furthermore, the small diameter pipe 433 is inserted into the introduction space V1.

[0063] According to this embodiment, the circumferential length of the seal (sealing mechanism 440) that seals the motive flow nozzle 430 and the casing 20 is shortened. This simplifies the sealing mechanism 440. This improves the production efficiency of the ejector 410 and reduces the manufacturing cost of the ejector 10. Furthermore, since the areas requiring sealing can be made smaller, leakage of the suction fluid W2 can be more reliably prevented. Furthermore, there is no need to ensure a volume in the casing 20 necessary to accommodate the large-diameter pipe 31. This allows the casing 20 to be made thinner. This allows for space savings.

[0064] (Other embodiments) The above describes in detail the embodiments of the present disclosure with reference to the drawings, but the specific configuration is not limited to this embodiment, and design changes and the like are also included within the scope that does not deviate from the gist of the present disclosure.

[0065] In the above embodiment, the ejector 10 is used in the refrigeration cycle of the turbo chiller 1, but the present invention is not limited to this. The ejector 10 may also be used in a refrigeration / cooling cycle other than that of the turbo chiller 1.

[0066] In the above embodiment, the driving fluid W1 and the suction fluid W2 are both liquids, but this is not limiting. For example, both the driving fluid W1 and the suction fluid W2 may be gas, or either one of the driving fluid W1 and the suction fluid W2 may be gas.

[0067] <Additional Notes> The ejectors 10, 210, 310, and 410 described in the respective embodiments can be understood as follows, for example.

[0068] (1) An ejector (10, 210, 310, 410) according to a first aspect includes a casing (20, 320) having a base (21) through which a suction fluid (W2) is supplied to an inner introduction space (V1), a tapered section (22) connected to the introduction space (V1) and forming a tapered space (V2) that gradually reduces in diameter toward one side in the direction of the axis (O), and a mixing tube (23) that forms a mixing space (V3) extending from the tapered space (V2) toward one side in the direction of the axis (O); a driving flow nozzle (30, 230, 430) extending about the axis (O) and inserted into the introduction space (V1) from the other side in the direction of the axis (O), with a tip opening (34) from which a driving fluid (W1) is ejected located within the tapered space (V2); and a movement mechanism (50, 250) that changes the position of the tip opening (34) along the axis (O) within a range of positions of the tapered space (V2) along the axis (O). The movement mechanisms 50 and 250 include, for example, electric mechanisms using ball screws or the like.

[0069] According to this aspect, the ejector 10, 210, 310, 410 can change the position of the tip opening 34 in the axial direction O within the tapered space V2. This allows changing only the flow path cross section Ams of the suction fluid W2 at the position of the tip opening 34 in the axial direction O, thereby changing the area ratio (Ams / Amd) of the flow path cross section Ams of the suction fluid W2 to the flow path cross section Amd of the driving fluid W1.

[0070] (2) The ejector 10, 310, 410 of the second aspect may be the ejector 10, 310, 410 of (1), and the movement mechanism 50 may move the entire motive flow nozzle 30, 430 relative to the casing 20 in the direction of the axis O, thereby varying the position of the tip opening 34 in the direction of the axis O.

[0071] According to this aspect, the movement mechanism 50 can vary the position of the distal end opening 34 in the direction of the axis O with a simple configuration.

[0072] (3) The ejector 210 of a third aspect is the ejector 210 of (1), wherein the movement mechanism 250 may extend or retract only one side of the driving flow nozzle 230 in the direction of the axis O, including the tip opening 34, in the direction of the axis O, thereby making it possible to change the position of the tip opening 34 in the direction of the axis O.

[0073] According to this aspect, the movement mechanism 250 can change the position of the tip opening 34 in the direction of the axis O without moving the seal between the motive flow nozzle 230 and the casing 20.

[0074] (4) The ejector 310 of the fourth aspect is any one of the ejectors 310 of (1) to (3), wherein the casing 320 covers the base 21 from the outside to form a pre-introduction space V5 between the base 21 and the casing 320, and further has an outer casing 321 through which the suction fluid W2 is supplied into the pre-introduction space V5, and a communication portion 323 that connects the introduction space V1 and the pre-introduction space V5 may be formed around the entire circumference of the side wall 25 of the base 21.

[0075] According to this aspect, the ejector 310 can supply the suction fluid W2 into the introduction space V1 from the entire periphery of the side wall 25 of the base 21 through the communication portion 323. This allows the ejector 310 to uniformize the flow rate distribution of the suction fluid W2 in the circumferential direction.

[0076] (5) The ejector 310 of a fifth aspect is the ejector 310 of (4), and the communication portion 323 may be a slit 324 extending in the circumferential direction of the axis O.

[0077] According to this aspect, the communication portion 323 can be easily formed in the side wall 25 of the base portion 21 .

[0078] (6) The ejector 310 of a sixth aspect is the ejector 310 of (4), wherein the communication portion 323 may be a plurality of holes 325 arranged in the circumferential direction of the axis O.

[0079] According to this aspect, the ejector 310 can make the flow rate distribution of the suction fluid W2 in the circumferential direction more uniform.

[0080] (7) The ejector 410 of a seventh aspect is the ejector 410 of any one of (1) to (6), wherein the driving flow nozzle 430 has a large diameter pipe 31 provided on the other side in the direction of the axis O and a small diameter pipe 433 provided on one side in the direction of the axis O and having a diameter smaller than that of the large diameter pipe 31, wherein the entire large diameter pipe 31 is located on the other side in the direction of the axis O of the base 21, and the small diameter pipe 433 may be inserted into the introduction space V1.

[0081] According to this embodiment, the circumferential length of the seal that seals the motive flow nozzle 430 and the casing 20 is shortened. Also, it is not necessary to ensure in the casing 20 the volume required to accommodate the large diameter pipe 31.

[0082] (8) The ejector 10, 210, 310, 410 of the eighth aspect is the ejector 10, 210, 310, 410 of any one of (1) to (7), wherein the casing 20, 320 may further have a diffuser portion 24 that is connected to the mixing space V3 and forms a diffuser space V4 whose diameter gradually increases toward one side in the direction of the axis O.

[0083] According to this aspect, the ejectors 10, 210, 310, and 410 can diffuse the fluid mixed in the mixing tube 23 in the diffuser portion 24 and cause it to expand. [Explanation of symbols]

[0084] 1...Centrifugal chiller 2...Compressor 3...Condenser 4...Expansion valve 5...Evaporator 6...Moving flow piping 7...Suction flow piping 8...Return piping 10...Ejector 20...Casing 21...Base 22...Tapered section 23...Mixing tube 24...Diffuser section 25...Side wall 26...Bottom 27...Suction hole 28...Insertion hole 30...Moving flow nozzle 31...Large diameter tube 32...Connecting tube 33...Small diameter tube 34...Tip opening 40...Sealing mechanism 50...Moving mechanism 210...Ejector 230...Moving flow nozzle 233...Small diameter tube 240...Sealing mechanism 250...Moving mechanism 251...Antenna 260...Operating device 310...Ejector 320...Casing 321...Outer casing 322...Suction hole 323...Communicating section 324...Slit 325...Hole 410...Ejector 430...Moving flow nozzle 433...Small diameter pipe 440...Sealing mechanism Amd...Flow path cross section (of driving fluid) Ams...Flow path cross section (of suction fluid) O...Axis V1...Introduction space V2...Tapered space V3...Mixing space V4...Diffuser space V5...Pre-introduction space W...Refrigerant W1...Drive fluid W2...Suction fluid W3...Mixed fluid

Claims

1. a casing including: a base portion through which a suction fluid is supplied to an inner introduction space; a tapered portion connected to the introduction space and forming a tapered space whose diameter gradually decreases toward one side in an axial direction; and a mixing tube forming a mixing space extending from the tapered space toward the one side in the axial direction; a driving flow nozzle extending about the axis and inserted into the introduction space from the other side in the axial direction, the nozzle having a tip opening for ejecting a driving fluid located within the tapered space; a moving mechanism that changes the axial position of the tip opening within a range of the axial position of the tapered space; Equipped with The motive flow nozzle is a large diameter pipe provided on the other side in the axial direction; a small diameter pipe provided on one side in the axial direction and having a diameter smaller than that of the large diameter pipe; and the small-diameter pipe has a tip opening formed at one end in the axial direction, The outer circumferential surface of the small diameter pipe is arranged along the axial direction in a cross section along the axial direction, In the tapered space, only the small diameter tube is movable.

2. the movement mechanism moves the entire motive flow nozzle relative to the casing in the axial direction to vary the axial position of the tip opening. The ejector according to claim 1 .

3. the movement mechanism extends and contracts only one axial side of the driving flow nozzle including the tip opening in the axial direction, thereby varying the axial position of the tip opening. The ejector according to claim 1 .

4. A casing having a base portion through which suction fluid is supplied to an inner introduction space, a tapered portion connected to the introduction space and forming a tapered space whose diameter gradually decreases toward one side in the axial direction, and a mixing tube forming a mixing space extending from the tapered space toward one side in the axial direction; a driving flow nozzle extending about the axis and inserted into the introduction space from the other side in the axial direction, the nozzle having a tip opening for ejecting a driving fluid located within the tapered space; a moving mechanism that changes the axial position of the tip opening within a range of the axial position of the tapered space; Equipped with The movement mechanism is an ejector that varies the axial position of the tip opening by extending and contracting only one axial side of the driving flow nozzle including the tip opening in the axial direction.

5. the casing further includes an outer casing that covers the base from the outside and forms a pre-introduction space between the base and the outer casing, and the suction fluid is supplied into the pre-introduction space; A communication portion that communicates the introduction space with the pre-introduction space is formed on the side wall of the base portion along the entire periphery. The ejector according to any one of claims 1 to 4.

6. A casing having a base portion through which suction fluid is supplied to an inner introduction space, a tapered portion connected to the introduction space and forming a tapered space whose diameter gradually decreases toward one side in the axial direction, and a mixing tube forming a mixing space extending from the tapered space toward one side in the axial direction; a driving flow nozzle extending about the axis and inserted into the introduction space from the other side in the axial direction, the nozzle having a tip opening for ejecting a driving fluid located within the tapered space; a moving mechanism that changes the axial position of the tip opening within a range of the axial position of the tapered space; Equipped with the casing further includes an outer casing that covers the base from the outside and forms a pre-introduction space between the base and the outer casing, and the suction fluid is supplied into the pre-introduction space; The ejector has a side wall of the base portion formed with a communication portion around the entire periphery, which communicates the introduction space with the pre-introduction space.

7. The communication portion is a slit extending in a circumferential direction of the axis. The ejector according to claim 6.

8. The communication portion is a plurality of holes arranged in a circumferential direction of the axis. The ejector according to claim 6.

9. The motive flow nozzle is a large diameter pipe provided on the other side in the axial direction; a small diameter pipe provided on one side in the axial direction and having a diameter smaller than that of the large diameter pipe; and the entire large diameter pipe is located on the other side of the base portion in the axial direction, The small diameter tube is inserted into the introduction space.

9. The ejector according to claim 4, 6, 7 or 8.

10. 9. The ejector according to claim 1, wherein the casing further includes a diffuser portion that is connected to the mixing space and forms a diffuser space whose diameter gradually increases toward one side in the axial direction.

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