JP2005233026A - Ejector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ejector for controlling the flow amount of refrigerant passing therethrough with the displacement of a needle valve while preventing the displacement of the needle valve to the side of reducing the flow amount of the refrigerant when refrigerant pressure on the flow-in side of high pressure refrigerant suddenly rises. <P>SOLUTION: A high pressure space 18 into which the high pressure refrigerant flows from an inlet 17a is partitioned into a space 18a on the side of a jet and a space 18b on the opposite side to the jet with a piston portion 19b formed integrally with the needle valve 19 as a flow amount control means. The inlet 17a is arranged in the space 18a on the side of the jet. Besides, a communication passage 17d is arranged for communicating a throttle portion 17c for converting the pressure energy of the refrigerant into velocity energy with the space 18b on the opposite side of the jet. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention is an ejector (see JIS Z 8126 No. 2.1.2.3, etc.) that is a decompression means for decompressing a fluid and that transports fluid by the entrainment action of a working fluid ejected at high speed. Therefore, the present invention is effective when applied to a refrigerator, a vehicle air conditioner, or the like that employs an ejector as a decompression means for decompressing the refrigerant and a pump means for circulating the refrigerant.

  Conventionally, an ejector used as a refrigerant decompression unit and a refrigerant circulation unit in a refrigeration cycle is known in Patent Document 1 for adjusting the flow rate of the refrigerant passing through the ejector.

  In the ejector 50 of the conventional example described in Patent Document 1 in FIG. 4, the refrigerant having a high pressure in the compressor flows into the high-pressure space 18 through the inlet 51. Thereafter, the passage area of the high-pressure refrigerant is reduced by the restriction portion 17c of the nozzle 17, whereby the pressure energy is converted into velocity energy, accelerates, and is ejected from the ejection port 17b. Due to the entraining action of the jetted high-speed refrigerant flow, the vapor-phase refrigerant evaporated by the evaporator is sucked from the vapor-phase refrigerant inlet 23.

  Further, the refrigerant passes through the mixing unit 21 and flows to the diffuser unit 22. The ejector reduces the consumption power of the compressor on the downstream side of the refrigerant flow by converting the expansion energy of the refrigerant into pressure energy and increasing the refrigerant pressure on the suction side of the compressor by the diffuser portion 22. After passing through the diffuser unit 22, the refrigerant is separated into a liquid-phase refrigerant and a gas-phase refrigerant by a gas-liquid separator, the gas-phase refrigerant is sucked into a compressor, and the liquid-phase refrigerant is evaporated by an evaporator to become a gas-phase refrigerant. It reaches the phase refrigerant inlet 23.

  In the conventional example, the needle valve 19 is displaced in the nozzle axial direction (left-right direction in FIG. 4) R, thereby changing the opening of the throttle portion 17c, that is, the nozzle 17 (flow passage area through which the refrigerant can pass). Thus, the flow rate of the refrigerant passing through the nozzle 17 can be increased or decreased. In the conventional example, when the needle valve 19 is displaced in the jet direction (right direction in FIG. 4) R1, the opening degree of the nozzle 17 is reduced, and when the needle valve 19 is displaced in the opposite direction (left direction in FIG. 4) R2, the nozzle 17 The opening of becomes larger.

According to this, when the compressor rotates at a high speed, that is, when there is a large amount of refrigerant flowing into the ejector 50, the opening degree of the nozzle 17 can be increased to increase the amount of refrigerant passing through the nozzle 17 (ejector 50). Therefore, since the amount of refrigerant flowing through the evaporator on the downstream side of the refrigerant flow of the ejector 50 increases, the refrigeration (cooling) capacity when the amount of refrigerant flowing through the cycle is larger than when the flow rate of refrigerant passing through the ejector 50 cannot be increased or decreased. Can be improved.
JP 2003-185275 A

  However, in the conventional example, if the pressure of the refrigerant flowing into the high-pressure space 18 and going toward the outlet 17b suddenly increases when the rotation speed of the compressor suddenly increases, the needle valve 19 moves from the refrigerant to the outlet ( (Right direction in FIG. 4) The force to R1 is received. That is, the needle valve 19 is displaced in a direction to reduce the opening degree of the nozzle 17.

  In particular, when the refrigerant circulation amount is small and the needle valve 19 reduces the opening of the nozzle 17, the needle valve 19 may block the nozzle 17 if the refrigerant pressure rapidly increases. As a result, the pressure of the high-pressure side piping becomes abnormally high, which causes a problem of damaging the piping.

  In view of the above points, the present invention provides an ejector that adjusts the flow rate of refrigerant passing through the displacement of the needle valve, and reduces the refrigerant flow rate of the needle valve when the refrigerant pressure on the side into which high-pressure refrigerant flows suddenly increases. The purpose is to prevent displacement.

In order to achieve the above object, according to the first aspect of the present invention, the high pressure space (18) into which the high pressure fluid flows from the inflow port (17a) and the high pressure from the high pressure space (18) to the fluid jet port (17b) are provided. A throttle means (17) having a throttle portion (17c) for reducing the passage area of the fluid, and displacement in the axial direction (R) of the throttle portion (17c) in the high-pressure space (18) An ejector that is a momentum transport pump that includes a needle valve (19) that changes a degree of opening) and that transports fluid by the entrainment action of a working fluid ejected from the fluid ejection port (17b) at high speed,
When the needle valve (19) is displaced in the direction (R1) of the fluid jet outlet in the axial direction (R), the opening of the throttle part (17c) is reduced, while the side opposite to the fluid jet outlet in the axial direction (R). Displacement in the direction (R2) increases the opening of the throttle part (17c),
The needle valve (19) includes a piston portion (19b) that partitions the high-pressure space (18) into a space (18a) on the fluid ejection port (17b) side and a space (18b) opposite to the fluid ejection port (17b). Is integrally formed,
When the fluid toward the fluid outlet (17b) displaces the needle valve (19) in the fluid outlet side direction (R1), the piston portion (19b) is pressurized in the direction opposite to the fluid outlet (R2). It is characterized by receiving.

  According to this, when the fluid heading toward the fluid outlet (17b) displaces the needle valve (19) in the fluid outlet side direction (R1), for example, the pressure of the fluid toward the fluid outlet (17b) suddenly increases. In such a case, the piston portion (19b) receives pressure in the direction (R2) opposite to the fluid ejection port. That is, the needle valve (19) increases the opening of the throttle part (17c).

  As a result, when the pressure of the fluid toward the fluid ejection port (17b) suddenly increases, the needle valve (19) closes the throttle portion (17c), and the pressure in the high-pressure space (18) becomes abnormally high. Can be prevented from being damaged.

In the invention according to claim 2, in the ejector according to claim 1, the inflow port (17a) is disposed in the space (18a) on the fluid jet port (17b) side,
Furthermore, the communication part (17d) which connects a throttle part (17c) and the space (18b) on the opposite side to the fluid ejection port (17b) is arranged.

  By the way, the pressure energy of the fluid is converted into velocity energy at the throttle portion (17c) of the nozzle (17). Therefore, the pressure of the fluid decreases from the pressure value of the space (18a) on the fluid ejection port (17b) side toward the fluid ejection port (17b).

  Therefore, the pressure in the space (18b) opposite to the fluid outlet (17b) communicates with the throttle portion (17c) having a lower pressure than the space on the opposite side (18b) through the communication passage (17d). The pressure is lower than the space (18a) on the fluid ejection port (17b) side.

  At this time, when the pressure of the fluid toward the fluid outlet (17b), that is, the pressure of the space (18a) on the fluid outlet (17b) side suddenly increases, the pressure of the opposite side space (18b) decreases, and the outlet side space Therefore, the piston portion (19b) partitioning both spaces (18a, 18b) receives pressure in the direction opposite to the fluid ejection port (R2).

  Thereby, the needle valve (19) integrated with the piston part (19b) is displaced in the direction (R2) opposite to the fluid outlet, that is, the needle valve (19) increases the opening of the throttle part (17c). Can do. Therefore, the displacement of the needle valve (19) can be mechanically controlled to exhibit the same effect as that of the first aspect.

In the invention according to claim 3, in the ejector according to claim 1, the inflow port (17a) is disposed in the space (18a) on the fluid ejection port (17b) side, and the piston portion (19b) is provided with a fluid A piston communication path (19c) is formed to communicate the space (18a) on the jet outlet (17b) side and the space (18b) opposite to the fluid jet outlet (17b),
The high-pressure fluid flows into the inlet (17a) → the space (18a) on the fluid outlet (17b) side → the piston communication path (19c) → the space (18b) opposite to the fluid outlet (17b) → the fluid outlet (17b) ) In that order.

  Here, the passage area of the piston communication passage (19c) is naturally smaller than the passage area of the fluid in the space (18a) on the fluid ejection port (17b) side. Therefore, also in the piston communication passage (19c), the pressure energy of the fluid is converted into velocity energy in the same manner as the throttle portion (17c) described above. That is, the space (18b) opposite to the jet outlet on the downstream side of the fluid flow in the piston communication passage (19c) rather than the fluid pressure in the fluid jet side space (18a) on the upstream side of the fluid flow in the piston communication passage (19c). The fluid pressure at) is lower.

  Also in this manner, as in the first aspect, when the pressure in the space (18a) on the fluid ejection port (17b) side suddenly increases, the pressure difference between the two spaces (18a, 18b) increases, so the piston portion (19b) And the needle valve (19) integral with the fluid nozzle are displaced in the direction (R2) opposite to the fluid ejection port, that is, the needle valve (19) can increase the opening of the throttle portion (17c). Therefore, the displacement of the needle valve (19) can be controlled mechanically.

  In addition, the code | symbol in the bracket | parenthesis of each said means shows the correspondence with the specific means as described in embodiment mentioned later.

(First embodiment)
In the present embodiment, the ejector according to the present invention is applied to a refrigeration cycle of a vehicle air conditioner, and FIG. 1 is a schematic diagram of the refrigeration cycle according to the present embodiment. In FIG. 1, 11 is a compressor 11 that sucks and compresses refrigerant. The refrigerant that has become a high pressure state by the compressor 11 flows into the radiator 12. In the radiator 12, the refrigerant radiates heat to the outdoor air, in other words, the refrigerant is cooled by the outdoor air.

  The cooled refrigerant flows into the ejector 13. The ejector 13 decompresses and expands the refrigerant flowing out of the radiator 12 and sucks the gas-phase refrigerant evaporated in the evaporator 16 described later, and converts the expansion energy into pressure energy to increase the suction pressure of the compressor 11. ing. Details of the ejector 13 will be described later.

  The refrigerant that has flowed out of the ejector 13 flows into the gas-liquid separator 14. In the gas-liquid separator 14, the refrigerant that has flowed is separated into a gas-phase refrigerant and a liquid-phase refrigerant and stored, and the separated gas-phase refrigerant is sucked into the compressor 11 and compressed again. The liquid refrigerant thus drawn is sucked to the evaporator 16 side.

  The evaporator 16 exhibits cooling capability by heat-exchanging the liquid-phase refrigerant with the air blown into the room and evaporating. The first decompressor 15 disposed between the gas-liquid separator 14 and the evaporator 16 is a throttle (decompression) means for decompressing the liquid-phase refrigerant sucked from the gas-liquid separator 14 to the evaporator 16 side. The pressure in the evaporator 16 (evaporation pressure) is reliably reduced by the first decompressor 15.

  Next, the ejector 13 according to the present invention will be described with reference to FIG. 2. The ejector 13 mainly includes a nozzle 17 that depressurizes the refrigerant, and circulation (suction), mixing, and pressure increase of the refrigerant mainly on the downstream side of the refrigerant flow of the nozzle 17. It can be roughly divided into the parts that perform

  The nozzle 17 is provided with an inflow port 17a into which the high-pressure refrigerant that has passed through the radiator 12 flows, a high-pressure space 18 formed inside the nozzle, and an outlet 17b through which the refrigerant is ejected from the nozzle. In addition, a tapered throttle portion 17c is formed in a portion between the high-pressure space 18 and the jet port 17b so that the passage area of the high-pressure refrigerant decreases from the high-pressure space 18 toward the jet port 17b. Further, the nozzle 17 is formed with a communication passage 17d that communicates between the throttle portion 17c and the jetting outlet and the opposite space 18b (described later).

  In addition, a needle valve 19 that adjusts the flow rate of the refrigerant passing through the nozzle 17 by changing the opening degree of the throttle portion 17b by being displaced in the axial direction R of the nozzle 17 is disposed in the high-pressure space 18 in the nozzle 17. ing.

  The needle valve 19 is a substantially needle-shaped rod-like member, and a tapered portion 19a whose cross section becomes smaller toward the ejection port side direction R1 is formed at the end of the ejection port side direction R1. Further, a piston portion 19b having a shape corresponding to a cross section perpendicular to the axial direction R of the high-pressure space 18 and partitioning the high-pressure space 18 into a jet outlet side space 18a and a jet outlet opposite space 18b It is integrally formed. In this embodiment, as an example of means for displacing the needle valve 19, a solenoid that converts electromagnetic energy into mechanical linear motion is used. In the figure, reference numeral 20 denotes a solenoid coil.

  Further, a mixing portion 20 having a substantially constant cross-sectional passage cross section is formed on the refrigerant flow downstream side of the jet port 17b, and further, the refrigerant flow downstream side of the mixing portion 21 gradually decreases in the refrigerant flow downstream direction. A diffuser portion 22 having an increased cross-sectional area is formed. A gas-phase refrigerant inlet 23 through which the gas-phase refrigerant from the evaporator 16 flows into the ejector 13 is disposed below the jet port 17b in the drawing.

  Next, the operation of the refrigeration cycle and the ejector 13 will be described with reference to FIGS. When the compressor 11 is started, gas-phase refrigerant is sucked into the compressor 11 from the gas-liquid separator 14, and the compressed refrigerant is discharged to the radiator 12. And the refrigerant | coolant cooled with the heat radiator 12 flows in into the jet outlet side space 18a from the inflow port 17a of the nozzle 17 of the ejector 13. FIG. Thereafter, the refrigerant flows toward the jet port 17b (arrow A in FIG. 2).

  At this time, the refrigerant is decompressed and expanded by restricting the passage area by the restricting portion 17c. In other words, the pressure energy is converted to velocity energy. Note that the pressure in the space 18b on the opposite side of the throttle portion 17c and the ejection port is substantially the same by the communication passage 17d. Since the refrigerant is gradually depressurized by the throttle portion 17c, the refrigerant pressure in the opposite side space 18b is lower than the pressure in the jet outlet side space 18a.

  Further, the amount of refrigerant passing through the throttle portion 17 c is adjusted by the needle valve 19 being displaced in the axial direction R of the nozzle 17 by the solenoid 20. When the needle valve 19 is displaced in the jet outlet side direction R1, the tapered portion 19a gradually fits into the throttle portion 17c, reducing the passage area of the refrigerant (reducing the refrigerant flow rate), while the needle valve 19 is opposite to the jet port. When displaced in the direction R2, the taper portion 19a is separated from the throttle portion 17c to increase the refrigerant passage area (increase the refrigerant flow rate).

  The refrigerant that has passed through the throttle portion 17c is ejected from the ejection port 17b at a high speed. At this time, the refrigerant that has become a gas phase in the evaporator 16 is sucked from the gas phase refrigerant inlet 23 by the high-speed jet flow. The refrigerant jetted from the jet port 17 b and the gas phase refrigerant sucked from the gas phase refrigerant inlet 23 flow to the diffuser part 22 while being mixed in the mixing part 21. Then, the dynamic pressure of the refrigerant is converted into a static pressure by the diffuser unit 22 and returns to the gas-liquid separator 14. On the other hand, since the refrigerant in the evaporator 16 is sucked by the ejector 13, the liquid-phase refrigerant flows from the gas-liquid separator 14 into the evaporator 16, and the refrigerant that flows in absorbs heat from the air blown into the room and evaporates. To do.

  Next, the operation and effect of the first embodiment will be described. When the pressure of the refrigerant flowing in from the inlet 17a suddenly increases, the needle valve 19 is displaced so as to increase the refrigerant flow rate of the throttle portion 17c. It is possible to prevent damage to members such as piping due to abnormally high pressure.

  In this embodiment, the piston part 19b is arrange | positioned at the needle valve 19, and the high voltage | pressure space 18 is divided into the space 18a by the side of a jet nozzle, and the space 18b on the opposite side to a jet nozzle. Further, a communication path 17d that communicates with the space 18b opposite to the throttle portion 17c is disposed. According to this, the space 18b opposite to the jet port communicates with the throttle portion 17c where the refrigerant pressure becomes low because the pressure energy of the refrigerant is converted into velocity energy. Therefore, in the space on both sides of the piston portion 19b of the needle valve 19, the pressure in the space 18b opposite to the jet port is small and the pressure in the jet port side space 18a is large.

  When the pressure of the refrigerant flowing into the jet outlet side space 18a from the inlet 17a toward the jet outlet 17b suddenly increases, the pressure in the space 18b opposite to the jet outlet is small, and the pressure in the jet outlet side space 18a is small. Therefore, the piston portion 19b that partitions both spaces 18a and 18b receives pressure in the direction R2 opposite to the jet port, that is, the needle valve 19 increases the opening of the throttle portion 17c. .

  Thereby, even when the pressure of the refrigerant toward the jet port 17b suddenly increases, the needle valve 19 closes the throttle portion 17c, the pressure in the high-pressure space 18 becomes abnormally high, and the piping member or the like is damaged. Can be prevented.

  In addition, since the displacement of the needle valve 19 is mechanically controlled, software control for abnormally high pressure is unnecessary.

(Second Embodiment)
In the first embodiment, the pressure difference is created on both sides of the piston portion 19b by the communication passage 17d that communicates the throttle portion 17c with the ejection port and the opposite space 18b. However, in the present embodiment shown in FIG. In addition, a piston communication passage 19c is formed to communicate the ejection side space 17a and the ejection space opposite to the ejection space 18b. Further, a passage 18c that communicates from the opposite space 18b to the ejection port 17b is disposed in the nozzle 17. The high-pressure refrigerant that has flowed into the nozzle 17 from the inlet 17a flows in the direction of arrow B in the figure. Thereafter, the refrigerant flows through the piston communication passage 19c to the space 18b opposite to the jet outlet. After that, it flows from the space 18b opposite to the jet port toward the jet port 17b as indicated by an arrow C.

  Here, the passage area of the piston communication passage 19c is naturally smaller than the passage area of the refrigerant in the outlet side space 18a. Therefore, the pressure energy of the refrigerant is also converted into velocity energy in the piston communication path 19c. That is, the refrigerant pressure in the space 18b opposite to the refrigerant outlet downstream of the refrigerant flow in the piston communication passage 19c is lower than the refrigerant pressure in the jet outlet side space 18a upstream of the refrigerant flow in the piston communication passage 19c. Become.

  Also by this, when the pressure in the ejection port side space 18a suddenly increases as in the first embodiment, the needle valve 19 integral with the piston portion 19b is displaced in the direction R2 opposite to the ejection port, that is, the needle valve 19 is The opening degree of the throttle portion 17c can be increased.

(Other embodiments)
In the first and second embodiments described above, an example in which the high-pressure space 18 is formed in the nozzle 17 has been shown. However, the high-pressure space 18 is formed inside the ejector 13 body as in the conventional example of FIG. May be. At this time, the inlet is naturally formed not in the nozzle 17 but in the main body of the ejector 13.

  In the first and second embodiments described above, the example in which the needle valve 19 is displaced by the solenoid has been shown. However, any needle valve 19 may be used as long as the needle valve 19 can be displaced in the axial direction R of the throttle portion 17c. The force may be converted into a linear displacement in the axial direction R.

It is a schematic diagram which shows the refrigerating cycle of the vehicle air conditioner which concerns on 1st Embodiment to which the ejector of this invention is applied. It is sectional drawing of the ejector which concerns on 1st Embodiment of this invention. It is sectional drawing which shows the nozzle of the ejector which concerns on 2nd Embodiment of this invention. It is sectional drawing which shows the ejector of patent document 1 (conventional example).

Explanation of symbols

17 ... throttle means (nozzle), 17a ... inflow port, 17b ... fluid ejection port (ejection port),
17c ... throttle part, 17d ... communication path, 18 ... high pressure space,
18a: Fluid ejection port side space (ejection port side space),
18b ... Space opposite to the fluid jet (opposite space), 19 ... Needle valve,
19b ... Piston part, 19c ... Piston communication path, R ... Axial direction of throttle part,
R1... Direction of fluid outlet side, R2... Direction opposite to fluid outlet.

Claims (3)

A high-pressure space (18) into which a high-pressure fluid flows from an inflow port (17a); and a throttle portion (17c) that reduces the passage area of the high-pressure fluid from the high-pressure space (18) toward the fluid jet port (17b). A throttle valve (19) and a needle valve (19) that changes the opening of the throttle part (17c) by displacing in the axial direction (R) of the throttle part (17c) in the high-pressure space (18). And an ejector that is a momentum transporting pump that transports fluid by the entrainment action of the working fluid ejected at a high speed from the fluid ejection port (17b),
When the needle valve (19) is displaced in the direction (R1) of the fluid jet outlet in the axial direction (R), the opening of the throttle portion (17c) is reduced, while the fluid jet in the axial direction (R) is reduced. When it is displaced in the direction opposite to the outlet (R2), the opening of the throttle part (17c) is increased.
The needle valve (19) includes a piston that partitions the high-pressure space (18) into a space (18a) on the fluid ejection port (17b) side and a space (18b) on the opposite side to the fluid ejection port (17b). The part (19b) is integrally formed,
When the fluid toward the fluid outlet (17b) displaces the needle valve (19) in the fluid outlet side direction (R1), the piston portion (19b) is in a direction opposite to the fluid outlet. An ejector characterized by receiving pressure on (R2). The inlet (17a) is disposed in the space (18a) on the fluid outlet (17b) side,
2. The ejector according to claim 1, wherein a communication passage (17 d) that communicates the throttle portion (17 c) and the space (18 b) opposite to the fluid ejection port (17 b) is disposed. The inlet (17a) is disposed in the space (18a) on the fluid outlet (17b) side,
The piston portion (19b) has a piston communication passage (19c) that communicates the space (18a) on the fluid ejection port (17b) side and the space (18b) opposite to the fluid ejection port (17b). Formed,
The high-pressure fluid flows into the inlet (17a) → the space (18a) on the fluid outlet (17b) side → the piston communication path (19c) → the space (18b) opposite to the fluid outlet (17b) → The ejector according to claim 1, wherein the ejector flows in the order of the fluid ejection port (17 b).

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