JP2009191635A - Gas machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a compressor capable of improving compression efficiency, by enhancing heat exchange efficiency of a spray drop. <P>SOLUTION: This gas machine has an impeller 3, a casing body 10 storing the impeller 3 and forming a flow passage R<SB>1</SB>for sending gas toward the impeller 3, and an ultrasonic vibration type spray device 30 arranged on the upstream side of the impeller 3 of the flow passage R<SB>1</SB>and spraying the spray drop F in air A<SB>O</SB>sent at a predetermined flow speed. The spray drop F is set to 1 m/s or more in a flow speed flowing in the impeller 3. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

The present invention relates to a gas machine. The gas machine is a concept including a compressor and a blower. The compressor includes a machine having a process of pressurizing a gas, such as a gas turbine, a diesel engine, a gas engine, and a gasoline engine.

In the conventional compressor, in order to improve the compression efficiency, a method is adopted in which droplets are sprayed on the intake air to reduce the intake air temperature in the casing including the impeller, the screw, and the like (for example, Patent Documents 1 and 2). ). Such a compressor has a two-fluid nozzle (spray) structure in which a system for supplying gas (air) and a system for supplying water are separated.
JP 2003-184768 A JP 56-98591 A

The spray droplets mixed with the intake air evaporate during the compression process, thereby depriving the compression heat of the compressed air, and the necessary power can be reduced by such a heat exchange action.
However, depending on the particle size of the spray droplets, a part thereof may not be vaporized and sent to the diffuser. Such droplets cannot contribute to reducing the temperature of the compressed air, but have a problem that power is increased (compression efficiency is lowered).

  The present invention has been made in view of the above-mentioned problems of the prior art, and aims to provide a compressor capable of improving the heat exchange efficiency of spray droplets and improving the compression efficiency. Yes.

  In order to solve the above problems, the compressor of the present invention contains a gas compression means, a casing in which the gas compression means is accommodated and a flow path for supplying gas toward the gas compression means is formed, An ultrasonic vibration type spraying device that is disposed upstream of the gas compression means in the flow path and sprays liquid droplets into the gas fed at a predetermined flow rate. The flow velocity flowing into the gas compression means is 1 m / s or more.

  In the present invention, it is preferable that the peak of the particle size distribution of the fine droplets is 2 μm or less.

  Moreover, in this invention, it is preferable that an ultrasonic vibration type spraying apparatus has a storage part which stores a liquid, and several ultrasonic transducer | vibrators which give a vibration to a liquid.

According to the present invention, the following effects can be obtained.
The droplets sprayed by the ultrasonic vibration type spraying device (hereinafter referred to as spray droplets) are directly exposed to the gas sent at a predetermined flow rate, so that the spray droplets are sheared, split and miniaturized. . In the present invention, conventional spray droplets can be generated by ultrasonic vibration, and the spray droplets are split by the influence of the shearing of the air and become fine particles having a smaller particle size. The particle size of the fine particles can promote atomization of spray droplets by adjusting the gas flow rate. For example, if the gas flow rate is 1 m / s or more, the average particle size peak is 2 μm or less. Fine particles can be generated. Therefore, part or most of the fine particles evaporate before flowing into the gas compression means, and the already cooled gas can flow into the gas compression means. Thereby, the temperature rise of compressed air can be suppressed more effectively, it becomes possible to improve the heat exchange efficiency of an apparatus and to reduce compression power.
Therefore, the gas compression means is not damaged, and so-called drain erosion is prevented.

  According to the compressor of the present invention, it is possible to improve the heat exchange efficiency of the gas and prevent the temperature rise of the compressed gas due to the compression of the gas in the energy application region, and to improve the compression efficiency of the compressed gas and mechanical damage. Prevents high reliability.

  Embodiments of the present invention will be described below with reference to the drawings. In each drawing used for the following description, the scale of each member is appropriately changed to make each member a recognizable size.

[First Embodiment]
1 is a schematic diagram showing a schematic configuration of a centrifugal compressor according to an embodiment of the present invention, FIG. 2 is a perspective view showing a schematic configuration of an impeller, FIG. 3 is an enlarged view of a main part of FIG. 1, and FIG. It is a principal part enlarged view of a vibration type spray apparatus.

  As shown in FIGS. 1 to 3, the centrifugal compressor 1 (gas machine) includes an impeller 3 (gas compression means) that compresses air A (gas) by centrifugal force, and a rotary shaft 9 that transmits rotational force to the impeller 3. The casing body 10 that houses the impeller 3, the ultrasonic vibration type spraying device 30 that sprays droplets in the air A, and the like.

  As shown in FIG. 2, the impeller 3 is formed of an impeller body portion 4 connected to one end of the rotating shaft 9 and a plurality of blades 5 arranged radially on the impeller body portion 4. Arranged around the rotation center axis O at equal intervals.

  As shown in FIG. 1, the rotation shaft 9 is supported by the casing body 10 and can rotate around the rotation center axis O. And the impeller 3 rotates when the impeller of the turbine (not shown) connected with the other end of the rotating shaft 9 or the gear apparatus of a motor drive rotates.

The casing body 10 includes a suction section casing 12 that forms a flow path from the inlet B to the impeller 3, and a storage section casing that houses the impeller 3 and forms a flow path from the suction section casing 12 to the diffuser 20 together with the impeller 3. 14, a diffuser 20 that forms a flow path from the accommodating part casing 14 to a scroll part 22 described later, and a scroll part 22 that forms a flow path from the diffuser 20 to the outlet C. It is a thing. Each passage communicates with a series of flow paths communicating to the outlet port C located at the most downstream portion of the scroll portion 22 as a flow path R ₁ from the inlet B via the impeller 3.

The suction portion casing 12 has a hollow circular shape when viewed from the axial direction of the rotation center axis O and is connected to the housing portion casing 14 until the air A ₀ flowing from the inlet B flows into the impeller 3. Form.

The housing casing 14 is housed so as to wrap the impeller 3 and is configured to rotatably support the rotating shaft 9. The inner wall of the housing casing 14 functions as a shroud, and forms a flow path with the impeller 3 until the air A ₁ that has flowed into the impeller 3 flows into the diffuser 20.

  The diffuser 20 includes diffuser forming surfaces 21a and 21b that face each other in the axial direction of the rotation center axis O. The diffuser forming surfaces 21 a and 21 b are connected to the housing casing 14 at the inner peripheral edge portions and connected to the scroll portion 22 at the outer peripheral edge portions.

And the flow-path cross-sectional area of the diffuser 20 which flows from the impeller 3 to the scroll part 22 is comprised so that it may become large gradually in a radial direction. In this figure, so-called vanes (guide vanes) are not attached. The diffuser 20 forms a flow path until the inflowing air A ₂ flows into the scroll portion 22.

The scroll portion 22 is connected to the outer peripheral edge portions of the diffuser forming surfaces 21a and 21b, and is configured to wrap around a part of the suction portion casing 12 and the accommodating portion casing 14 around the rotation center axis O. . Further, the cross-sectional shape along the rotation center axis O is a hollow circle, and is configured such that the cross-sectional area of the flow path increases as it proceeds to the downstream side of the flow path.
The scroll portion 22 forms a flow path of the air A ₃ flowing from the diffuser 20 from the outlet C of the downstream side of the scroll unit 22 to be discharged to the outside.

As shown in FIG. 3, the ultrasonic vibration type spray device 30 is disposed in the space K of the suction portion casing 12, and each spray mechanism 31 is fixed to the inner wall of the suction portion casing 12 by a support portion (not shown). Has been. Each spray mechanism 31 includes a liquid storage portion 32 that stores the liquid E, and a plurality of ultrasonic transducers 33 that are disposed at a predetermined interval on the bottom portion 32 a of the liquid storage portion 32.
As shown in FIG. 4, each ultrasonic transducer 33 is fixed to the bottom 32 a so that the covering material 34 disposed on the terminal surface 33 a is exposed from the opening 32 </ b> A of the liquid reservoir 32.

Such an ultrasonic vibration type spraying device 30 atomizes the liquid E in the liquid storage part 32 by the plurality of ultrasonic vibrators 33 arranged on the bottom part 32a, and generates the generated spray droplets F as shown in FIG. It is adapted to spray into the air a in ₀ which has flowed from the inlet port B shown. In this embodiment, water is used as the liquid E, but a liquid other than water may be used.

  The ultrasonic vibration type spraying device 30 generates mist-like spray droplets F by applying vibration energy to the liquid E and reducing the surface tension of the liquid surface by the action of the ultrasonic vibrator 33. Here, the Sauter average particle size of the generated spray droplets F is 10 μm or less, and in this embodiment, the Sauter average particle size is about 3 to 6 μm or less by adjusting the frequency of the ultrasonic transducer 33. Spray droplets F can be generated.

Further, the liquid E is always supplied into the liquid storage section 32 by a liquid supply mechanism (not shown), and an optimal water level h (see FIG. 4) is secured.
In addition, in the liquid storage part 32, you may make it provide the liquid detection sensor etc. which detect the storage amount of the liquid E, for example. By this liquid detection sensor, the water level h suitable for atomization by the ultrasonic vibrator 33 can be maintained, the optimum particle diameter can be maintained, and damage to the ultrasonic vibrator 33 due to air blowing can be prevented.

  Further, as shown in FIG. 3, a filter member 38 is disposed in the vicinity of the inlet B and upstream of the ultrasonic vibration type spraying device 30. The filter member 38 suppresses intrusion of foreign matter or floating substances in the gas into the casing body 10.

Next, the effect | action of a centrifugal compressor provided with the structure mentioned above is demonstrated using FIGS.
First, the operation of the centrifugal compressor ₁ will be described along the flow path R1.
As the impeller of a turbine (not shown) connected by the rotary shaft 9 rotates, the impeller 3 rotates. Then, by the rotation of the impeller 3, the pressure of the air A ₀ of the suction casing 12 is lower than the pressure of the outside air A, the air A is sequentially flows from the inflow port B. At this time, the air _A0 is set to a predetermined flow rate by adjusting the rotation of the impeller 3. In the present embodiment, the flow rate of the air A ₀ is set to be 1 m / s or higher.

The air A ₀ flowing through the suction section casing 12 flows into the housing section casing 14 by the rotation of the impeller 3. When the air A ₀ flows through the suction casing 12, the spray droplet F is sprayed into the air A ₀ by the ultrasonic vibration type spray device 30. At this time, the spray droplet F is sheared into fine particles by the air A ₀ flowing in a direction substantially orthogonal to the spray direction of the spray droplet F. In other words, shearing force and ejection direction of the atomized droplets F from the liquid reservoir 32, since the direction of flow of air A ₀ flowing suction casing 12 is in a direction substantially intersecting the air flow through the suction casing 12 As a result, the spray droplets F are further split, and uniform fine particles having a small particle diameter are obtained.

The suction portion casing 12 has a reduced diameter on the housing portion casing 14 side. At the reduced diameter portion of the suction casing 12, the velocity energy increases and the impeller 3 enters a negative pressure state (a state where the pressure is reduced below the saturated vapor pressure). The atomized air A ₀ gradually evaporates as the particulates in the air A ₀ flow into the housing casing 14 due to a negative pressure state in the reduced diameter portion of the suction casing 12. Reduce moisture. In addition, since the negative pressure state is the most in the vicinity of the entrance of the housing casing 14 (impeller 3) that houses the impeller 3, many fine particles are evaporated in this portion. Incidentally, before entering into the housing casing 14 (the impeller 3) inside, it is desirable that the fine particles in the air A ₀ is completely evaporated. The temperature of the air A ₀ is lowered by the action of the heat of vaporization. The air A ₀ ′ thus cooled flows into the housing casing 14 by the rotation of the impeller 3.

In reduced diameter portion of the suction casing 12 by velocity energy of the air A ₀ is increased, it is conceivable to atomization and evaporation is more accelerated.

Pressure energy and velocity energy are given to the air A ₁ flowing through the impeller 3 by the centrifugal force of the impeller 3. That is, while passing through the impeller 3, the pressure energy and velocity energy of the air A ₁ is increased. Air A ₁ flowing through the impeller 3, since it is pre-cooled air stream, it is possible to reduce the causes than the conventional compression power in the impeller 3.

Further, when fine particles (atomized droplets F) was left in the air A ₁ is able to completely evaporate the residual particulates in the energy imparting region of the impeller 3 (or residual atomized droplets). Since the air A ₁ flowing into the impeller 3 is a precooled air flow, the temperature of the air A ₁ is further lowered by the heat of vaporization accompanying evaporation of the residual fine particles, so that the necessary drive power is effectively reduced. Can be lowered.

Then, the air A _{1 that} has passed through the impeller 3 becomes air A ₂ and flows into the diffuser 20. The cross-sectional area of the flow path of the diffuser 20 increases as it proceeds in the radial direction of the diffuser 20. Therefore, to decrease the velocity energy of the air A ₂ through the diffuser 20, the pressure energy increases correspondingly.

Thereafter, the air A _{2 that} has passed through the diffuser 20 flows into the scroll portion 22. A part of the velocity energy of the air A ₃ flowing through the scroll part 22 is further converted into pressure energy by the increase in the flow path cross-sectional area of the scroll part 22. Then, the air A ₃ whose pressure has further increased is discharged from the outlet C downstream of the scroll portion 22 to the outside.

In this way, the air A ₁ flowing through the impeller 3 is accelerated and compressed by the rotation of the impeller 3 and is further boosted by being sent to the diffuser 20.

FIG. 5 shows the particle size distribution of the fine particles under each measurement condition. However, the broken line in the figure is the expected line.
Measurement Conditions (flow velocity of the air _{A 0: 0.4m / s, 0.8m} / s, 1m / s, 5m / s) the particle size distribution of the fine particles in shifts towards its peak value is smaller particle sizes I understand that In the case of a flow rate of 0.4 m / s, as shown in the figure, fine particles having a particle size of 6 to 10 μm that are difficult to evaporate are included, and these fine particles are sprayed by the ultrasonic vibration type spray device 30. It is almost the same as the particle size of the droplet F.
In addition, when the flow rate was 0.8 m / s, a distribution having a peak near the particle size of 3 μm was obtained, but the particle size was not sufficiently atomized.

In this measurement, particularly when the flow rate of air A ₀ was 1 m / s and 5 m / s, a particle size distribution having a particle size of 2 μm or less as a peak was obtained.
When the flow rate is 1 m / s, the peak particle is about 1.5 μm, and the atomized air A ₀ evaporates even before flowing into the impeller 3 side, and can be sufficiently evaporated even inside the compressor.

  When the flow rate is 5 m / s, the peak of the particle diameter is about 1 μm or less. Here, since it was not possible to measure particles having a particle size of 1 μm or less, the peak value of the particle size distribution cannot be declared, but evaporation can be completed both upstream and inside the compressor. .

  Thus, it has been found that when the air flow velocity is 1 m / s or more, uniform fine particles having a small particle size are generated. That is, the higher the flow velocity of the airflow flowing in the direction substantially intersecting the spray droplets F from the ultrasonic vibration type spray device 30, the more the spray droplets F can be divided into fine particles having a smaller particle diameter.

FIG. 6 is a PV diagram of the centrifugal compressor of the present embodiment.
The broken line in the figure shows the PV characteristic when the air flow temperature T1 is 30 degrees, and the solid line in the figure shows the PV characteristic when the air flow temperature T2 is 25 degrees.
When the temperature of the air flow, that is, the temperature T1 of the air flowing into the impeller 3 is 30 degrees, the air flow sucked into the housing casing 14 at a predetermined pressure Ps has a volume from V1s to V1m due to the action of the impeller 3. By reducing, the pressure is compressed to Pm. When the air flow temperature T2 is 25 degrees, the air flow sucked into the housing casing 14 at a predetermined pressure Ps is compressed to the pressure Pm by reducing the volume from V2s to V2m by the action of the impeller 3. Is done.
Here, the hatched portion in the figure represents the difference in compression power between the case where the temperature of the airflow is 25 degrees and the case of 30 degrees, and the cold airflow reduces the compression power only in the hatched portion. This enables energy-saving operation of the centrifugal compressor.

FIG. 7 is a PV diagram of a conventional centrifugal compressor.
The broken line in FIG. 7 shows the PV characteristics of the centrifugal compressor not provided with the ultrasonic vibration type spraying device, and the solid line in the drawing is the centrifugal compressor having the ultrasonic vibration type spraying device (miniaturization). not) the air a ₁ containing atomized droplets showing a P-V characteristics when flowed into the impeller.
When the temperature at the time of flowing into the impeller 3 is the same, the case where the air flow including the spray droplets F flows into the impeller 3 as compared with the case where the air flow not containing moisture flows into the impeller 3 However, the temperature of the air flow decreases due to the gas heating accompanying the evaporation of the spray droplets F before the discharge, and the compression power is reduced. However, as in the above-described embodiment, the case where the air flow in a cooled state is introduced into the impeller 3 is more effective because the compression power can be significantly reduced.

In the present embodiment, the air droplet A ₀ flowing in the suction casing 12 at a predetermined flow velocity (1 m / s or more) hits the spray droplet F generated from the ultrasonic vibration spray device 30 and sprayed droplets. F is sheared into fine particles. For example, by setting the flow rate of the air A ₀ to 5 m / s, it is desirable to atomize more spray droplets F and generate fine particles having a smaller particle diameter.

As described above, by forming the spray droplets F into fine particles having a smaller particle size, the fine particles in the air A ₀ are almost completely evaporated near the entrance of the housing casing 14, that is, before flowing into the impeller 3. Can do. Since easily evaporates as the particle diameter of the fine particles contained in the air A ₀ is small, thereby improving the heat exchange efficiency. The vaporization heat due to evaporation of the fine particles of the air A _0, lowered temperature of air A ₀ is may send cool air into the impeller 3. Even if fine particles remain in the air A ₁ flowing into the impeller 3, the residual fine particles are completely evaporated in the energy application region of the impeller 3. By vaporization heat due to the evaporation can reduce the temperature of air A _1. Thereby, the cooling efficiency of the impeller 3 is improved.

  As a result, the temperature increase of the impeller 3 (compressed gas) can be satisfactorily prevented, and as a result, the compression efficiency and mechanical strength of the impeller 3 are improved, thereby providing a highly reliable centrifugal compressor 1. Can do.

Incidentally, fine particles of the atomized droplets F may be adjusted by changing the flow rate of air A ₀ being air intake unit casing 12. The greater the shearing force applied to the spray droplets F, the more the spray droplets F are refined into fine particles having a smaller particle diameter. Therefore, it is desirable that the flow rate of the air A ₀ is appropriately set according to the device structure, the spray amount and the particle size of the spray droplets F, and the heat exchange efficiency is improved to reduce the compression power.

  In addition, this invention is not limited to embodiment mentioned above, In the range which does not deviate from the meaning of this invention, it can change suitably. For example, the present invention can be applied to a blower in addition to the general compressor.

For example, the present invention can be applied to a turbo compressor other than the centrifugal type (for example, a mixed flow type or an axial flow type) or a volumetric compressor. An example of the axial flow compressor is a gas turbine compressor.
Further, the centrifugal compressor 1 of the present embodiment can be applied to an engine supercharger, an industrial compressor, or a gas turbine. Similarly, the air compression process of a diesel engine or a gasoline engine can be exactly the same. Moreover, although the said embodiment demonstrated the 1-stage centrifugal compressor, this invention is applicable similarly also to multistage-type centrifugal compressors, such as a 2-stage centrifugal compressor.

  In the above-described embodiment, air is introduced, but nitrogen or oxygen may be used depending on the type of apparatus. Also, the type of liquid to be sprayed may be alcohol or other refrigerant other than water.

  The configuration of the ultrasonic vibration type spraying device 30 is not limited to the above embodiment, and any configuration capable of spraying droplets into the air flowing in the suction portion casing 12 may be used.

The schematic diagram which shows schematic structure of the centrifugal compressor in the 1st Embodiment of this invention. The perspective view which shows schematic structure of an impeller. The principal part enlarged view of FIG. The expanded sectional view which shows the ultrasonic transducer | vibrator of an ultrasonic vibration type spraying apparatus. The particle size distribution of the fine particles under each measurement condition is shown. The diagram which shows the PV characteristic of the centrifugal compressor in this embodiment. The diagram which shows the PV characteristic of the conventional centrifugal compressor.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Centrifugal compressor (gas machine), 3 ... Impeller (gas compression means), 5 ... Blade | wing, 10 ... Casing main body, 12 ... Suction part casing, 14 ... Storage part casing, 20 ... Diffuser, E ... Liquid, F ... Spray droplet, R ₁ ... flow path, A ₀ , A ₁ , A ₂ ... air, 30 ... ultrasonic vibration type spray device, 32 ... liquid reservoir, 33 ... ultrasonic transducer, 38 ... filter member

Claims (3)

Gas compression means;
A casing in which a flow path for containing the gas compressing means and supplying gas toward the gas compressing means is formed;
An ultrasonic vibration type spraying device that is disposed on the upstream side of the gas compression means in the flow path and sprays liquid droplets into the gas fed at a predetermined flow rate,
The gas machine according to claim 1, wherein the droplet has a flow velocity of 1 m / s or more flowing into the gas compression unit.   The gas machine according to claim 1, wherein a peak of a particle size distribution of the fine droplets is 2 µm or less.   3. The ultrasonic vibration type spraying device includes a storage unit that stores a liquid and a plurality of ultrasonic vibrators that vibrate the liquid. 4. Gas machine.

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