WO2023210124A1

WO2023210124A1 - Ejector

Info

Publication number: WO2023210124A1
Application number: PCT/JP2023/005781
Authority: WO
Inventors: 吉輝小室; 喜之近藤; 紘章中西; 浩一谷本
Original assignee: 三菱重工業株式会社
Priority date: 2022-04-28
Filing date: 2023-02-17
Publication date: 2023-11-02
Also published as: JP2023163948A

Abstract

This ejector comprises: a casing having a base portion that has an inner introduction space supplied with suction fluid, a tapered portion that forms a tapered space connected to the introduction space and gradually decreasing in diameter toward one side in the axial direction, and a mixing tube that forms a mixing space extending from the tapered space to the one side in the axial direction; a drive flow nozzle that extends about the axis and is inserted into the introduction space from the other side in the axial direction, and that has a tip opening for jetting out drive fluid, the tip opening being located in the tapered space; and a movement mechanism that allows the axial position of the tip opening to be variable within the range of the axial position of the tapered space.

Description

ejector

The present disclosure relates to an ejector.
This application claims priority based on Japanese Patent Application No. 2022-075200 filed in Japan on April 28, 2022, the contents of which are incorporated herein.

For example, Patent Document 1 discloses an ejector that is applied to a refrigeration cycle using a mixed refrigerant. This ejector has a nozzle that converts the pressure energy of the high-pressure refrigerant flowing out of the condenser into velocity energy to decompress and expand the refrigerant, and a high-velocity refrigerant flow ejected from the nozzle that sucks in the gaseous refrigerant that has evaporated in the evaporator. It has a booster section. The pressure booster mixes the refrigerant ejected from the nozzle with the refrigerant sucked from the evaporator, converts velocity energy into pressure energy, and boosts the pressure of the refrigerant.

Japanese Patent No. 3433737

However, in the ejector described in Patent Document 1, the flow of the refrigerant is determined by three pressures: the high-pressure refrigerant supplied, the refrigerant sucked, and the pressure booster where these refrigerants are mixed. For this reason, it has been difficult to vary the suction flow rate within a fixed cycle.

The present disclosure has been made to solve the above problems, and an object of the present disclosure is to provide an ejector that can easily change the suction flow rate.

In order to solve the above problems, an ejector according to the present disclosure includes a base portion through which suction fluid is supplied to an inner introduction space, and a tapered space that is connected to the introduction space and whose diameter gradually decreases toward one side in the axial direction. a casing having a mixing tube forming a mixing space extending from the tapered space to one side in the axial direction; and a casing extending around the axis and inserted into the introduction space from the other side in the axial direction. a driving flow nozzle whose tip opening for ejecting driving fluid is located in the tapered space; and a moving mechanism that makes the axial position of the tip opening variable within the range of the axial position of the tapered space. , is provided.

According to the ejector of the present disclosure, the suction flow rate can be easily changed.

FIG. 1 is a schematic diagram of a refrigeration cycle of a centrifugal refrigerator according to a first embodiment of the present disclosure. FIG. 1 is a perspective view of an ejector according to a first embodiment of the present disclosure. FIG. 1 is a cross-sectional view of an ejector according to a first embodiment of the present disclosure. FIG. 2 is a perspective view showing a tip opening of a driving flow nozzle according to a first embodiment of the present disclosure. FIG. 3 is a cross-sectional view of an ejector according to a second embodiment of the present disclosure. FIG. 7 is a perspective view of an ejector according to a third embodiment of the present disclosure. FIG. 3 is a cross-sectional view of an ejector according to a third embodiment of the present disclosure. FIG. 7 is a perspective view of an ejector according to a modification of the third embodiment of the present disclosure. FIG. 7 is a cross-sectional view of an ejector according to a modification of the third embodiment of the present disclosure. FIG. 7 is a cross-sectional view of an ejector according to a fourth embodiment of the present disclosure.

<First embodiment>
(turbo chiller)
Hereinafter, a turbo chiller 1 equipped with an ejector 10 according to an embodiment of the present disclosure will be described with reference to FIGS. 1 to 4.
The turbo refrigerator 1 is a cooling device using a turbo compressor such as a centrifugal compressor. The centrifugal chiller 1 is used, for example, as an air conditioner in large-scale facilities such as office buildings. FIG. 1 shows an example of a refrigeration cycle of a turbo chiller 1.

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

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 liquid. The expansion valve 4 reduces the pressure of the refrigerant W from the condenser 3. The evaporator 5 evaporates the liquid refrigerant W whose pressure has been reduced by the expansion valve 4, and exchanges heat with the 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 blown into the room to be cooled. The refrigerant W that has been evaporated into a gas in the evaporator 5 is sent to the compressor 2 again. In this way, the refrigerant W circulates within the refrigeration cycle of the turbo chiller 1.
As the refrigerant W, for example, a fluorocarbon gas, a fluorocarbon substitute, or the like is used.

In the following, the flow direction of the refrigerant W in the refrigeration cycle will be simply referred to as the "flow direction", the upstream of the flow direction will be simply referred to as "upstream", and the downstream of the "flow direction" will be simply referred to as "downstream". be.

The evaporator 5 of this embodiment is a liquid film type evaporator. Therefore, unevaporated liquid refrigerant W is stored at the bottom of the evaporator 5. An ejector 10 is provided to recirculate the refrigerant W stored at the bottom of the evaporator 5.

(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 . Further, the ejector 10 is connected to the bottom of the evaporator 5 by a suction flow pipe 7. Liquid refrigerant W stored at 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. Further, the ejector 10 is connected to the upstream side of the evaporator 5 via a return pipe 8. The ejector 10 returns the refrigerant W supplied via the driving flow piping 6 and the suction flow piping 7 to the evaporator 5 via the return piping 8 .

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

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.

(casing)
The casing 20 is formed into a cylindrical shape extending in one direction.
Below, the axis O of the casing 20 may be simply referred to as "axis O" and explained. In addition, when the extending direction of the axis O is simply referred to as the "axis O direction," the radial direction of the axis O is simply referred to as the "radial direction," and the circumferential direction of the axis O is simply referred to as the "circumferential direction." There is. Further, in the axis O direction, the downstream side may be referred to as "one side in the axis O direction" and the upstream side may be referred to as "the other side in the axis O direction".
The casing 20 includes a base 21 , a tapered portion 22 , a mixing tube 23 , and a diffuser portion 24 .

(base)
The base portion 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. The 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 axis O direction.

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. The suction hole 27 is connected to the downstream end of the suction flow pipe 7 (the end opposite to the evaporator 5). The suction fluid W2 is supplied from the suction flow pipe 7 to the introduction space V1 through the suction hole 27.

The bottom portion 26 closes the other side of the side wall 25 in the axis O direction. The bottom portion 26 is formed into a disk shape 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 at the center of the bottom portion 26. The insertion hole 28 passes through the bottom portion 26 in the direction of the axis O.

(Tapered part)
The tapered portion 22 is provided at one end of the base portion 21 in the axis O direction. 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 whose diameter gradually decreases toward one side in the axis O direction. 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.

(mixing tube)
The mixing tube 23 is provided at one end of the tapered portion 22 in the axis O direction. The mixing tube 23 is formed into a cylindrical shape extending in the direction of the axis O. The mixing tube 23 is arranged coaxially with the tapered portion 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.

(Diffuser section)
The diffuser section 24 is provided at one end of the mixing tube 23 in the axis O direction. The diffuser part 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 expands in diameter toward one side in the axis O direction.

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

(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 tube 31 is inserted into an insertion hole 28 provided in the bottom 26 of the casing 20. The large diameter tube 31 is a cylindrical member extending in the direction of the axis O. The other end of the large diameter tube 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 pipe 6 (the end opposite to the condenser 3). A driving fluid W1 is supplied into the large diameter pipe 31 from the driving flow piping 6.

(Connection pipe)
The connecting pipe 32 is provided at one end of the large diameter pipe 31 in the axis O direction. The connecting pipe 32 is formed in a cylindrical shape extending from the large diameter pipe 31 to one side in the axis O direction. The connecting pipe 32 is arranged coaxially with the large diameter pipe 31. The connecting pipe 32 is formed in a tapered shape whose diameter gradually decreases toward one side in the direction of the axis O.

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

(Tip opening)
The tip opening 34 spouts out the driving fluid W1 supplied into the driving flow nozzle 30. The tip opening 34 is located within the tapered space V2. The cross-sectional shape of the tip opening 34 perpendicular to the axis O is circular.

(Seal mechanism)
The sealing mechanism 40 is disposed in an insertion hole 28 provided in the bottom 26 of the casing 20. A sealing mechanism 40 is provided between the insertion hole 28 and the driving flow nozzle 30. The seal mechanism 40 supports the driving flow nozzle 30 so as to be movable in the direction of the axis O. Further, the sealing mechanism 40 seals the casing 20 and the driving flow nozzle 30 to prevent the refrigerant W from leaking out 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.

(Moving mechanism)
The moving mechanism 50 makes the position of the tip opening 34 of the drive flow nozzle 30 in the axis O direction variable within the range of the position of the tapered space V2 in the axis O direction. That is, the range of motion of the tip opening 34 is within the tapered space V2. In this embodiment, the moving mechanism 50 moves the entire driving flow nozzle 30 in the direction of the axis O, thereby making the position of the tip opening 34 in the direction of the axis O variable. Examples of the moving mechanism 50 include an electric mechanism using a ball screw or the like.

(Ejector suction mechanism)
Next, the suction mechanism of the ejector 10 will be explained.
The pressure on the upstream side of the driving flow nozzle 30 (on the condenser 3 side) is higher than that on the downstream side of the driving flow nozzle 30. Due to this pressure difference, the driving fluid W1 flows into the driving flow nozzle 30 from the upstream side of the driving flow nozzle 30. The driving fluid W1 contracts in the tapered connecting pipe 32 of the driving flow nozzle 30. Thereby, the driving fluid W1 is depressurized and guided to the mixing space V3. Thereby, the pressure energy (expansion energy) of the driving fluid W1 is converted into velocity energy, and the driving fluid W1 is ejected from the tip opening 34 at high speed.

The driving fluid W1 ejected from the tip opening 34 sucks the refrigerant W stored at the bottom of the evaporator 5. The refrigerant W sucked from this evaporator 5 becomes suction fluid W2. Suction fluid W2 flows into introduction space V1 in casing 20 through suction flow piping 7. Furthermore, the suction fluid W2 is drawn toward one side (downstream side) in the axis O direction by the driving fluid W1. Thereby, the suction fluid W2 is guided from the introduction space V1 to the mixing space V3 through the tapered space V2.

In the mixing space V3, the driving fluid W1 and the suction fluid W2 flow toward the downstream side while being mixed. A mixed fluid W3 is generated by mixing the driving fluid W1 and the suction fluid W2. Mixed fluid W3 is guided from mixing space V3 to diffuser space V4.

In the diffuser space V4, the mixed fluid W3 flows toward the downstream side while being diffused. As a result, the pressure of the mixed fluid W3 is increased. The mixed fluid W3 whose pressure has been increased in the diffuser space V4 is sent from the ejector 10 to the downstream side (evaporator 5 side).

(effect)
Hereinafter, the effects of the ejector 10 of this embodiment will be explained.
In this embodiment, the tip opening 34 of the drive flow nozzle 30 that spouts the drive fluid W1 is located within the tapered space V2. The moving mechanism 50 makes the position of the tip opening 34 in the direction of the axis O variable within the range of the position of the tapered space V2 in the direction of the axis O.

The suction fluid W2 is sucked 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 and the flow path cross section Amd of the driving fluid W1 at the position in the axis O direction of the tip opening 34. be done. At the position of the tip opening 34 in the direction of the axis O, 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 cross section of the tip opening of the cross section of the tapered space V2. 34 excluding the cross section of the inner space. According to this embodiment, the ejector 10 can make the position of the tip opening 34 in the direction of the axis O variable within the tapered space V2. As a result, only the flow path cross section Ams of the suction fluid W2 at the position in the axis O direction of the tip opening 34 is changed, and the area ratio (Ams/Amd) of the flow path cross section Ams of the suction fluid W2 and the flow path cross section Amd of the driving fluid W1 is changed. ) can be changed. In this way, by simply changing the position of the tip opening 34, the area ratio (Ams/Amd) can be changed and the suction flow rate can be changed. Therefore, by using the ejector 10, the suction flow rate can be easily changed.

By changing the suction flow rate, it is possible to support partial load operation and load following operation of the centrifugal chiller 1. For example, during partial load operation, the pressure of the driving fluid W1 is lower than that at the rated time, so the flow rate of the driving fluid W1 decreases, and in that case, the flow rate of the suction fluid W2 generally also decreases. However, when used for refrigerant circulation in a liquid film evaporator, it is desirable to circulate a constant flow rate, so it is necessary to increase the ratio of the flow rate of the suction fluid W2 to the flow rate of the driving fluid W1. In that case, according to the ejector 10 of the present embodiment, by adjusting the position of the tip opening 34 of the driving flow nozzle 30 in the axis O direction, the flow path cross section Ams of the suction fluid W2 is expanded, and the flow rate of the driving fluid W1 is increased. The ratio of the flow rate of the suction fluid W2 to that of the suction fluid W2 can be increased.

In the present embodiment, the moving mechanism 50 moves the entire driving flow nozzle 30 in the direction of the axis O, thereby making the position of the tip opening 34 in the direction of the axis O variable.

According to this embodiment, the moving mechanism 50 can make the position of the tip opening 34 in the axis O direction variable 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.

In this embodiment, the casing 20 has a diffuser section 24 that is connected to the mixing space V3 and forms a diffuser space V4 that gradually expands in diameter toward one side in the axis O direction.

According to this embodiment, the ejector 10 can diffuse and expand the fluid mixed in the mixing tube 23 in the diffuser section 24. Thereby, the ejector 10 can increase the pressure of the mixed fluid W3 in the diffuser section 24 and then send it to the downstream side.

Furthermore, in this embodiment, the refrigerant W is sucked from the evaporator 5 by the ejector 10 and recirculated within the refrigeration cycle. By the way, when circulating refrigerant using a pump, for example, it is necessary to frequently maintain the movable parts of the pump, which increases maintenance costs. To begin with, there is no knowledge in the past of circulating liquid refrigerant within a cycle without using a pump. On the other hand, the ejector 10 sucks the liquid refrigerant W using the pressure difference within the cycle and circulates it within the cycle. Therefore, there is no need to use a pump to circulate the liquid refrigerant W. Therefore, maintenance costs for the pump become unnecessary, and costs can be reduced. Moreover, the frequency of maintenance of the centrifugal chiller 1 as a whole can be reduced.

Note that in the first embodiment, the case where the driving flow nozzle 30 is moved has been described, but the present invention is not limited to this. The driving flow nozzle 30 and the casing 20 may move relative to each other in the direction of the axis O. For example, the moving mechanism 50 and the casing 20 may be connected and the casing 20 may be moved in the direction of the axis O.

<Second embodiment>
Hereinafter, an ejector 210 according to a second embodiment of the present disclosure will be described with reference to FIG. 5. Configurations similar to those of the first embodiment described above will be given the same names and numerals, and descriptions thereof will be omitted as appropriate.

As shown in FIG. 5, the small diameter pipe 233 of the driving flow nozzle 230 is provided so as to be expandable and retractable in the direction of the axis O.
Further, the moving mechanism 250 of the present embodiment expands and contracts only one side of the driving flow nozzle 230 in the axis O direction that includes the tip opening 34 in the axis O direction, thereby making the position of the tip opening 34 in the axis O direction variable. The moving mechanism 250 includes, for example, an antenna 251 that is connected to the small diameter pipe 33 of the drive flow nozzle 30 and receives signals from the outside.

Furthermore, the ejector 210 has an operating device 260. The operating device 260 is installed outside the centrifugal chiller 1, for example. The user operates the operating device 260 to transmit an operating signal to the antenna 251. Thereby, when the antenna 251 receives an operation signal from the operation device 260, the moving mechanism 250 expands and contracts the small diameter tube 233 in the direction of the axis O according to the operation signal. Thereby, the position of the tip opening 34 in the direction of the axis O becomes variable.

In this embodiment, the moving mechanism 250 expands and contracts only one side of the driving flow nozzle 230 in the axis O direction that includes the tip opening 34 in the axis O direction, thereby making the position of the tip opening 34 in the axis O direction variable.

According to this embodiment, the moving mechanism 250 can make the position of the tip opening 34 in the axis O direction variable without moving the seal (seal mechanism 240) between the driving flow nozzle 230 and the casing 20. Therefore, leakage of the suction fluid W2 can be more reliably prevented.

<Third embodiment>
Hereinafter, an ejector 310 according to a third embodiment of the present disclosure will be described with reference to FIGS. 6 and 7. Configurations similar to those of the first embodiment described above will be given the same names and numerals, and descriptions thereof will be omitted as appropriate.

As shown in FIGS. 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 over the entire circumference 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 the introduction space V1.

A suction hole 322 is formed in the external casing 321. The suction hole 322 penetrates the outer casing 321 in the radial direction.

A communication portion 323 is formed on the side wall 25 around the axis O of the base portion 21 over the entire circumference to communicate the introduction space V1 and the pre-introduction space V5. The communication portion 323 of this embodiment is a slit 324 extending 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.

In this embodiment, the casing 320 further includes an external casing 321 that covers the base 21 from the outside to form a pre-introduction space V5 between the base 21 and the suction fluid W2 into the pre-introduction space V5. . A communication portion 323 is formed in the side wall 25 of the base portion 21 over the entire circumference to communicate the introduction space V1 and the pre-introduction space V5.

According to this embodiment, the suction fluid W2 is first guided from the suction flow piping 7 to the pre-introduction space V5. The suction fluid W2 spreads within the pre-introduction space V5 over the entire circumferential direction. Thereafter, the suction fluid W2 flows into the introduction space V1 via the communication portion 323. In this way, the ejector 310 of this embodiment can supply the suction fluid W2 from the entire circumference of the side wall 25 of the base 21 into the introduction space V1 via the communication portion 323. Thereby, the ejector 310 can uniformize the flow rate distribution of the suction fluid W2 in the circumferential direction.

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

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.

Next, a modification of the third embodiment will be described with reference to FIGS. 8 and 9.
As shown in FIGS. 8 and 9, the communication portion 323 may be a plurality of holes 325 arranged in the circumferential direction of the axis O. The hole 325 passes through the side wall 25 of the base 21 in the radial direction. The plurality of holes 325 are provided at equal intervals in the circumferential direction. The hole 325 is formed to have a circular cross section. Each hole 325 is all formed in the same shape.

In this modification, the communication portion 323 is a plurality of holes 325 arranged in the circumferential direction of the axis O.

According to the present embodiment, the ejector 310 can further uniformize the flow rate distribution of the suction fluid W2 in the circumferential direction.

<Fourth embodiment>
Hereinafter, an ejector 410 according to a fourth embodiment of the present disclosure will be described with reference to FIG. 10. Configurations similar to those of the first embodiment described above will be given the same names and numerals, and descriptions thereof will be omitted as appropriate.

As shown in FIG. 10, the entire large diameter pipe 31 of the driving flow nozzle 430 is located on the other side of the axis O direction than the base 21, and the small diameter pipe 433 of the driving flow nozzle 430 is inserted into the introduction space V1. There is. In this embodiment, the intermediate portion of the small diameter tube 433 in the direction of the axis O is located in the insertion hole 28 of the casing 20 . The seal mechanism 440 is provided around the entire circumference of the small diameter pipe 433.

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

According to this embodiment, the circumference of the seal (seal mechanism 440) that seals the driving flow nozzle 430 and the casing 20 is shortened. This simplifies the sealing mechanism 440. Therefore, the production efficiency of the ejector 410 can be improved, and the manufacturing cost of the ejector 10 can be reduced. Furthermore, since the area where sealing is required can be made smaller, leakage of the suction fluid W2 can be more reliably prevented. Further, there is no need to ensure a volume necessary for accommodating the large-diameter pipe 31 in the casing 20. Therefore, the casing 20 can be made thinner. This makes it possible to save space.

(Other embodiments)
Although the embodiment of the present disclosure has been described above in detail with reference to the drawings, the specific configuration is not limited to this embodiment, and includes design changes within the scope of the gist of the present disclosure. .

In addition, although the said embodiment demonstrated the case where the ejector 10 is used for the refrigeration cycle of the turbo chiller 1, it is not limited to this. The ejector 10 may be used in a refrigeration/cooling cycle other than the turbo chiller 1.

Note that in the above embodiment, the case where both the driving fluid W1 and the suction fluid W2 are liquids has been described, but the present invention is not limited to this. For example, the driving fluid W1 and the suction fluid W2 may both be gases, or either one of the driving fluid W1 and the suction fluid W2 may be a gas.

<Additional notes>
The

ejectors

10, 210, 310, and 410 described in each embodiment are understood as follows, for example.

(1) The

ejector

10, 210, 310, 410 according to the first aspect includes a base 21 that supplies suction fluid W2 to an inner introduction space V1, and a base 21 that is connected to the introduction space V1 and directed toward one side in the axis O direction. a

casing

20, 320 having a tapered portion 22 forming a tapered space V2 whose diameter gradually decreases in diameter; and a mixing pipe 23 forming a mixing space V3 extending from the tapered space V2 to one side in the direction of the axis O; A driving

flow nozzle

30, 230, 430 that extends around O and is inserted into the introduction space V1 from the other side in the direction of the axis O, and has a tip opening 34 for ejecting the driving fluid W1 located in the tapered space V2. and a moving

mechanism

50, 250 that makes the position of the tip opening 34 in the axis O direction variable within the range of the position of the tapered space V2 in the axis O direction.
Examples of the moving

mechanisms

50 and 250 include electric mechanisms using ball screws and the like.

According to this aspect, the

ejector

10, 210, 310, 410 can make the position of the tip opening 34 in the axis O direction variable within the tapered space V2. As a result, only the flow path cross section Ams of the suction fluid W2 at the position in the axis O direction of the tip opening 34 is changed, and the area ratio (Ams/Amd) of the flow path cross section Ams of the suction fluid W2 and the flow path cross section Amd of the driving fluid W1 is changed. ) can be changed.

(2) The

ejector

10, 310, 410 of the second aspect is the

ejector

10, 310, 410 of (1), in which the moving mechanism 50 moves the driving

flow nozzle

30, 430 with respect to the casing 20. The position of the tip opening 34 in the direction of the axis O may be made variable by relatively moving the entire body in the direction of the axis O.

According to this aspect, the moving mechanism 50 can make the position of the tip opening 34 in the axis O direction variable with a simple configuration.

(3) The ejector 210 of the third aspect is the ejector 210 of (1), in which the moving mechanism 250 moves only one side of the driving flow nozzle 230 in the axis O direction including the tip opening 34. The position of the tip opening 34 in the axis O direction may be made variable by expanding and contracting it in the axis O direction.

According to this aspect, the moving mechanism 250 can make the position of the tip opening 34 in the direction of the axis O variable without moving the seal between the driving flow nozzle 230 and the casing 20.

(4) The ejector 310 of the fourth aspect is the ejector 310 according to any one of (1) to (3), in which the casing 320 covers the base 21 from the outside and is introduced between the base 21 and the base 21. It further includes an external casing 321 that forms a front space V5 and supplies the suction fluid W2 into the pre-introduction space V5, and the side wall 25 of the base 21 has the introduction space V1 and the A communication portion 323 that communicates with the pre-introduction space V5 may be formed.

According to this aspect, the ejector 310 can supply the suction fluid W2 into the introduction space V1 from the entire circumference of the side wall 25 of the base portion 21 via the communication portion 323. Thereby, the ejector 310 can uniformize the flow rate distribution of the suction fluid W2 in the circumferential direction.

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

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

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

According to this aspect, the ejector 310 can further uniformize the flow rate distribution of the suction fluid W2 in the circumferential direction.

(7) The ejector 410 of the seventh aspect is the ejector 410 according to any one of (1) to (6), in which the driving flow nozzle 430 is connected to the large diameter pipe 31 provided on the other side in the direction of the axis O. and a small-diameter tube 433 provided on one side in the direction of the axis O and having a smaller diameter than the large-diameter tube 31, the entire large-diameter tube 31 being on the other side in the direction of the axis O than the base 21. The small diameter tube 433 may be inserted into the introduction space V1.

According to this aspect, the circumferential length of the seal that seals the driving flow nozzle 430 and the casing 20 is shortened. Further, there is no need to ensure a volume necessary for accommodating the large-diameter pipe 31 in the casing 20.

(8) The

ejector

10, 210, 310, 410 of the eighth aspect is the

ejector

10, 210, 310, 410 according to any one of (1) to (7), wherein the

casing

20, 320 is It may further include a diffuser portion 24 that is connected to the space V3 and forms a diffuser space V4 whose diameter gradually increases toward one side in the direction of the axis O.

According to this aspect, the

ejectors

10, 210, 310, and 410 can diffuse and expand the fluid mixed in the mixing tube 23 in the diffuser section 24.

According to the present disclosure, it is possible to provide an ejector that can easily change the suction flow rate.

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

Claims

a base portion through which suction fluid is supplied to the inner introduction space; a tapered portion connected to the introduction space to form a tapered space whose diameter gradually decreases toward one side in the axial direction; a casing having a mixing tube forming a mixing space extending to the side;
a driving flow nozzle extending around the axis and inserted into the introduction space from the other side in the axial direction, and having a tip opening for ejecting driving fluid located in the tapered space;
a moving mechanism that makes the axial position of the tip opening variable within the range of the axial position of the tapered space;
An ejector equipped with.
The moving mechanism moves the entire driving flow nozzle relative to the casing in the axial direction, thereby making the position of the tip opening variable in the axial direction.
The ejector according to claim 1.
The moving mechanism expands and contracts only one side of the drive flow nozzle in the axial direction that includes the tip opening, thereby making the axial position of the tip opening variable.
The ejector according to claim 1.
The casing further includes an outer casing that covers the base from the outside to form a pre-introduction space between the base and the suction fluid is supplied into the pre-introduction space,
A communication part that communicates the introduction space and the pre-introduction space is formed on the side wall of the base over the entire circumference.
An ejector according to any one of claims 1 to 3.
The communication portion is a slit extending in the circumferential direction of the axis,
The ejector according to claim 4.
The communication portion is a plurality of holes arranged in a circumferential direction of the axis,
The ejector according to claim 4.
The driven 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 smaller diameter than the large diameter pipe;
has
The entire large diameter tube is located on the other side of the base in the axial direction,
the small diameter tube is inserted into the introduction space;
An ejector according to any one of claims 1 to 3.
The ejector according to any one of claims 1 to 3, wherein the casing further includes a diffuser portion that is connected to the mixing space and forms a diffuser space that gradually expands in diameter toward one side in the axial direction.