JP2005016412A - Ejector and freezing system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ejector and a freezing system using the same, improving the efficiency by using a fluid control device utilizing a switching phenomenon of fluid based on Coanda effect. <P>SOLUTION: In the ejector for sucking and/or increasing pressure of secondary fluid by jets of primary fluid, the fluid control device 20 is connected with piping 12 supplying the primary fluid to a nozzle 1. An unsteady flow is formed in the primary fluid by using self-excited vibration of the fluid control device 20, and the interface between the primary fluid and the secondary fluid is made to be roughly perpendicular to a flowing direction of the fluid. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an ejector that is used for vacuum generation, compression, pressure increase, and the like, and more particularly, to an ejector that makes a primary fluid flow unsteady and a refrigeration system using the ejector.
[0002]
[Prior art]
The present applicant has proposed an ejector that generates an unsteady flow of the primary fluid such that the interface between the primary fluid and the secondary fluid is substantially perpendicular to the ejector axial direction as an ejector of this type (for example, , See Patent Document 1). The unsteady flow generating means is, for example, based on periodic heating control of a group of thin tubes provided in the primary fluid supply pipe, or periodic control of the primary fluid supply device such as a pump or an electromagnetic valve.
On the other hand, a fluid switching element used for an air current conveying device is disclosed for a fluid element using a fluid switching phenomenon based on the Coanda effect (see, for example, Patent Document 2).
[0003]
[Patent Document 1]
JP 2002-333000 A (Claims 1-6, FIGS. 1-7)
[Patent Document 2]
JP 2001-50214 A (paragraphs [0015]-[0018], FIG. 2)
[0004]
[Problems to be solved by the invention]
The ejector disclosed in Patent Document 1 is configured such that when a high energy fluid (primary fluid) and a low energy fluid (secondary fluid) are in direct contact, the interface between the two fluids is perpendicular to the flow direction. By alternately flowing the fluids, energy exchange between the two fluids is performed reversibly, which is intended to reduce the energy loss during mixing. That is, in order for the primary fluid and the secondary fluid to exchange energy (pressure) through the interface most efficiently, the interface should be perpendicular to the fluid flow direction. Therefore, in the technique of the above-mentioned Patent Document 1, an unsteady flow consisting of an intermittent flow or a pulsating flow is generated in the primary fluid. However, since the generation means is based on periodic heating control of a group of thin tubes provided in the primary fluid supply piping and periodic control of the primary fluid supply device such as a pump or a solenoid valve, control is inevitably performed from the outside. An additional control device is required. Therefore, since the control device is complicated, there is a problem that the reliability of the entire facility is impaired and the device is expensive. In addition, there is a problem that the control becomes more difficult as the frequency of the primary fluid is increased.
[0005]
On the other hand, as a means for controlling the fluid, the use of a fluid element utilizing a fluid switching phenomenon based on the Coanda effect is disclosed in Patent Document 2 described above. However, this document does not describe anything about using the ejector. And so far, no fluid element is used to control the primary fluid in the ejector.
[0006]
Therefore, an object of the present invention is to provide an ejector that improves efficiency by controlling the pressure and flow rate of a fluid using a fluid element, and a refrigeration system using the ejector.
[0007]
[Means for Solving the Problems]
An ejector according to the present invention uses a fluid element in a flow path for supplying a primary fluid in an ejector that sucks and / or pressurizes a secondary fluid by a jet of the primary fluid, and utilizes self-excited vibration of the fluid element. Thus, an unsteady flow is formed in the primary fluid.
[0008]
Moreover, in the ejector of this invention, the form of unsteady flow is made into intermittent flow or pulsation flow.
Here, “intermittent flow” refers to a flow in which the fluid intermittently flows in one direction, and there is a moment when the flow rate of the fluid becomes zero. “Pulsating flow” refers to a fluid flow rate that fluctuates with time in the main flow direction and does not become zero even at the moment when the flow rate is minimized.
In the present invention, an unsteady flow, that is, an intermittent flow or a pulsating flow is formed in the primary fluid by utilizing the self-excited vibration of the fluid element. Therefore, the secondary fluid is sandwiched between the primary fluid masses. In this state, the interface between the two fluids is substantially perpendicular to the fluid flow direction. Note that the interface here does not necessarily include a clear boundary but also includes a transition layer.
[0009]
Moreover, this invention can also comprise the ejector apparatus which supplies a primary fluid alternately with respect to several ejector using the fluid element of Claim 1. FIG.
Moreover, the refrigerating system of this invention comprises a refrigerating cycle using the ejector in any one of Claims 1-3.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, a basic embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing an outline of an ejector according to the present invention.
The ejector 10 is mainly composed of a nozzle 1 and a diffuser 2 in which the nozzle 1 is arranged concentrically. A primary fluid heating device 30 is connected to the upstream side of the primary fluid supply pipe 12 for supplying the primary fluid to the nozzle 1 via a fluid element 20, and self-excitation of fluid based on the fluid switching phenomenon of the fluid element 20. An unsteady flow of the primary fluid is formed by vibration and supplied to the nozzle 1.
One end of a secondary fluid supply pipe 14 is connected to the secondary fluid introduction part 3 of the diffuser 2, and the other end of the pipe 14 is connected to a secondary fluid supply device 32 that is a secondary fluid supply source. . The discharge flow whose energy is increased by the ejector 10 is supplied or discharged through the outflow pipe 16 to another process, a condenser, the atmosphere, or the like according to the purpose of use. In FIG. 1, reference numeral 18 denotes a primary fluid supply device such as a pump.
[0011]
FIG. 2 is an explanatory diagram for explaining the configuration and operation of the fluidic device 20 shown in FIG. The fluid element 20 has one input port 21, two output ports 22a and 22b, and two control ports 24a and 24b. The flow path inside the fluidic element 20 is formed by dividing the input port 21 and the output ports 22a and 22b into Y-shaped main flow paths 23a and 23b having an acute angle. The control channels 25 and 26 communicate with the ports 24a and 24b from both sides, respectively.
The input port 21 of the fluid element 20 and the primary fluid heating device 30 are connected by the input side pipe 12a of the primary fluid supply pipe 12, and the output side of the primary fluid supply pipe 12 is connected to one output port 22a. The pipe 12b is connected. Further, the output side pipe 12 b and the control port 24 a are connected by a control flow path 25, and the other output port 22 b and the control port 24 b are connected by a control flow path 26.
[0012]
By interposing the fluid element 20 configured in this way in the primary fluid supply pipe 12 connecting the primary fluid heating device 30 and the nozzle 1 of the ejector 10, the fluid element 20 is automatically generated by the self-excited vibration of the fluid based on the switching phenomenon of the fluid element 20. Thus, an unsteady flow of the primary fluid is generated.
That is, according to the operation principle of the fluid element 20, once the fluid entering from the input port 21 flows through the main channel 23a, it continues to take the channel 23a unless a control flow flows from the control port 24a. When there is an input from the control port 24a, the flow path is switched from 23a to 23b, and the flow path of 23b is continued unless a control flow is then flowed from the control port 24b.
[0013]
As described above, the fluid element 20 is interposed in the primary fluid supply pipe 12 that connects the primary fluid heating device 30 and the nozzle 1 of the ejector 10, and one output port 22 a is connected to the downstream side of the primary fluid supply pipe 12. A part thereof is connected to the control port 24 a via the flow path 25. The other output port 22b is connected to the control port 24b via the flow path 26.
The function of the fluid element 20 will be described.
(1) When a fluid flows from the input port 21 to the output port 22a, the pressure in the flow path 25 increases, and a control flow is input from the control port 24a.
(2) The main flow is switched from the flow path 23a to 23b by the input of the control flow from 24a.
(3) Then, the pressure in the flow path 26 increases, and the control flow flows into the control port 24b.
(4) When the control flow flows from 24b, the main flow is switched from the flow path 23b to 23a.
(5) Return to (1) and repeat the same operation.
[0014]
Therefore, as shown in the input waveform diagram shown in FIG. 2, for example, when a uniform flow is input to the input of the input port 21, the fluid itself causes self-excited vibration, and the output port 22a outputs As shown in the figure, a pulse-like signal is output.
According to the present embodiment, by utilizing such self-excited vibration of the fluid element 20, an intermittent flow or a pulsating flow having an arbitrary frequency of several tens of Hz to several kHz can be generated in the primary fluid.
Note that the time interval of self-excited vibration can be adjusted by arbitrarily adjusting the resistance of the flow channels 25 and 26 and the flow channel volume. In addition, the fluid element 20 in the present embodiment has shown a circuit configuration of the most basic fluid element called an adhesion type fluid element. However, a combination of a plurality of these fluid elements, or a fluid element called a vortex type or a collision type. It is possible to generate a pulse flow in the same manner.
[0015]
FIG. 3 schematically shows the flow of the primary fluid and the secondary fluid when an unsteady flow is formed in the primary fluid by the fluid element 20.
The primary fluid in a gas phase state by the primary fluid heating device 30 becomes an intermittent flow by the fluid element 20 and is ejected at a higher speed than the nozzle 1. At this time, the primary fluid mass 11 flows in the right direction of FIG. 3 due to the intermittent primary fluid flow, and the secondary fluid is sucked between the primary fluid masses 11 to form the secondary fluid mass 13. Flows to the right. The interface between the primary fluid mass 11 and the secondary fluid mass 13 forms a substantially vertical plane with respect to the flow direction of the fluid mass, and energy is transferred between the primary fluid mass 11 and the secondary fluid mass 13. After the transfer of energy, the primary fluid mass 11 and the secondary fluid mass 13 that are in substantially the same energy state are mixed and flow out to the outflow pipe 16 while restoring the velocity energy to pressure energy by the diffuser 2. Therefore, energy exchange between the primary fluid mass 11 and the secondary fluid mass 13 is performed through the vertical interface, and since mixing is performed after the energy states of both fluids are close to each other, loss of effective energy is suppressed, and the ejector Efficiency is improved.
[0016]
FIG. 4 is a conceptual diagram showing an example of an embodiment in which a refrigeration cycle is configured using the ejector 10 described above.
The ejector 10 is mainly composed of a nozzle 1, a diffuser 2, and a fluid element 20. The nozzle 1 is connected to a primary fluid heating device 30 via a primary fluid supply pipe 12 and a fluid element 20. The primary fluid heating device 30 includes, for example, a heat exchanger 31 for heating the primary fluid. Further, the evaporator 34 is connected to the secondary fluid introduction part 3 of the ejector 10 through the secondary fluid supply pipe 14. A condenser 36 is connected to the outflow side of the ejector 10 through an outflow pipe 16. The mixture of the primary fluid and the secondary fluid flowing into the condenser 36 is cooled by a cooling water pipe 38 connected to the condenser 36 and condensed. The condensed liquid flows through the pipe 15 and is returned to the primary fluid heating apparatus 30 by the primary fluid supply apparatus 18, and at the same time returns to the evaporator 34 via the secondary fluid return pipe 17 and the pressure reducing valve 19.
A temperature drop, that is, refrigeration occurs due to vaporization heat (latent heat of evaporation) of the secondary fluid generated when the secondary fluid in the evaporator 34 is sucked by the ejector 10, and a cooling load 35 connected to the evaporator 34. Cool down.
[0017]
By using the ejector 10, the efficiency of the ejector is improved as described above, so that the flow rate ratio of the secondary fluid to the primary fluid (= [secondary fluid flow rate] / [primary fluid flow rate]) increases, and the refrigerator As a result, the efficiency (COP) is improved.
[0018]
In addition, as a heat source of the heat exchanger 31 connected to the primary fluid heating device 30, factory exhaust heat, exhaust gas heat, and the like are used in addition to those by combustion of electric power and fuel. As the primary and secondary fluid refrigerant, water, chlorofluorocarbon, alcohol, ammonia, or a mixture thereof is used.
[0019]
FIG. 5 shows an example in which two ejectors 10 </ b> A and 10 </ b> B are driven simultaneously using the fluid element 20. Since the fluid element 20 can alternately send a pulse flow to the primary fluid supply pipes 12a and 12b, it is possible to drive two ejector devices simultaneously.
[0020]
【The invention's effect】
The ejector of the present invention forms an unsteady flow of the primary fluid by self-excited vibration of the fluid using the switching phenomenon of the fluid element, and the interface between the primary fluid and the secondary fluid of the unsteady flow is set vertically in the flow direction. To do. Thereby, the effective energy loss at the time of suction / mixing of the secondary fluid is reduced, and the efficiency of the ejector is improved. In other words, the flow rate ratio of the secondary fluid to the primary fluid (= [secondary fluid flow rate] / [primary fluid flow rate]) is increased, and the amount of primary fluid necessary to suck the unit amount of secondary fluid is reduced. . Incidentally, the ejector efficiency of the present invention is almost the same as that of Patent Document 1.
In addition, the present invention can form an unsteady flow of the primary fluid without any external control by using a fluid element, so that a complicated fluid control device is not required, and the reliability and durability of the equipment are eliminated. As a result, the cost can be easily reduced and the cost can be easily reduced.
[Brief description of the drawings]
FIG. 1 is a schematic diagram showing an example of an ejector according to the present invention.
FIG. 2 is an explanatory diagram for explaining the configuration and operation of a fluid element.
FIG. 3 is an operation explanatory view showing the flow of primary fluid and secondary fluid in the ejector of the present invention.
FIG. 4 is a schematic diagram showing an example of the refrigeration system of the present invention.
FIG. 5 is a schematic view showing another example of use of the ejector of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Nozzle 2 Diffuser 3 Secondary fluid introduction | transduction part 10, 10A, 10B Ejector 11 Primary fluid lump 12 Primary fluid supply piping 13 Secondary fluid lump 14 Secondary fluid supply piping 16 Outflow piping 20 Fluid element 21 Input port 22a, 22b Output port 23a, 23b Main flow paths 24a, 24b Control ports 25, 26 Control flow path 30 Primary fluid heating device 32 Primary fluid supply device 34 Evaporator 36 Condenser

Claims (4)

In an ejector that sucks and / or pressurizes a secondary fluid by a jet of the primary fluid, a fluid element is used in a flow path that supplies the primary fluid, and the self-excited vibration of the fluid element is used to make the primary fluid unsteady. Ejector characterized by forming a flow. 2. The ejector according to claim 1, wherein the unsteady flow is an intermittent flow or a pulsating flow. A primary fluid is alternately supplied to a plurality of ejectors using the fluid element according to claim 1. A refrigeration system comprising a refrigeration cycle using the ejector according to claim 1.

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