JPH06108991A - Surging preventing device for compressor - Google Patents

Abstract

PURPOSE:To provide a surging preventing device capable of preventing the generation of surging in the impeller of a compressor. CONSTITUTION:Air taken in through an intake hole 103 of a compressor 10 is compressed by an impeller 102 and a diffuser 106. The compressed air is partially led to a chamber 109 through a compressed air lead-in hole 107 and a connecting pipe 108 and jetted almost opposedly to the rotating direction of the impeller 102 from a compressed air jet hole 111 through a disc shape passage 112. The generation of vortex in an inducer 104 at the starting and speed increasing time is suppressed by this jetted compressed air so as to prevent the generation of surging.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a compressor,
In particular, the present invention relates to a surging prevention device for a compressor that can prevent surging that occurs in a gas turbine engine and an engine with a turbocharger.

[0002]

2. Description of the Related Art When the intake air flow rate taken into the compressor and the compression ratio of the compressor exceed a specified value at the same time,
It is known that surging occurs in which the impeller sounds or vibrates. Surging occurs when the flow of intake air stalls and separates in the compressor, but in a centrifugal compressor, the stall in the inducer and diffuser has the greatest effect.

When surging occurs, not only a sufficient intake air amount cannot be secured, but also mechanical damage may occur. However, since the compression efficiency of the compressor can be obtained at a flow rate near the surging limit, it is common to operate with the surplus limit being as close as possible, with some margin.

For this reason, there has been proposed a surging avoidance device in which a surge sensor is installed in the compressor, and when the occurrence of surging is detected, the amount of air extracted from the compressor is adjusted to avoid surging. 60-45732).

[0005]

However, as shown in FIG.
(A) (FIG. 5 is a development view in which the impeller is developed in the direction of the rotation axis, arrow Y indicates the rotation direction, and arrow Y indicates the inflow direction of intake air). Even if bleeding is performed as described above, the intake air stalls at the inducer at the tip of the impeller, and a vortex represented by arrow Z is generated, which may cause surging.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a surging prevention device for a compressor capable of preventing the occurrence of surging in an inducer.

[0007]

SUMMARY OF THE INVENTION A compressor surging prevention device according to the present invention comprises a compressed air source and a compressed air jet for injecting compressed air supplied from the compressed air source in a direction substantially opposite to a rotation direction of an impeller. And a hole.

[0008]

According to the surging prevention device for a compressor according to the present invention, the compressed air supplied from the compressed air source is jetted from the compressed air ejection holes so as to be substantially opposed to the impeller rotation direction, and the air in the inducer portion is ejected. Suppress the generation of eddies.

[0009]

FIG. 1 is a constitutional view of an embodiment of a surging prevention device for a compressor according to the present invention, in which (a) is a partial front view and (b) is a WW sectional view. Impeller 1 stored in the shroud 101 of the compressor 10.
When 02 rotates, air is taken in through the intake port 103,
The diffuser 106 fixed to the shroud 101 by being accelerated from the inducer 104 through the inter-blade passage 105.
Then, the velocity energy of the air is converted into pressure energy and becomes compressed air.

A compressed air introduction hole 107 is opened at an outlet position of the diffuser 106 of the shroud 101, and the compressed air is guided to a chamber 109 via a pressure guiding pipe 108. A solenoid valve 110 is installed in the middle of the pressure guiding tube 108. The compressed air introduction hole 107 is at the outlet of the impeller 102,
That is, it may be installed at the diffuser 106 inlet. The chamber 109 has a donut shape surrounding the outer periphery of the suction hole 103, and when the electromagnetic valve 110 is “open”, compressed air is introduced into the chamber 109.

A compressed air ejection hole 111 provided in the chamber 109 and the shroud 101 above the inducer 104.
A disk-shaped flow path 112 communicates with the above. A swirl vane 113 is installed in the disc-shaped flow path 112 to adjust the jetting direction of the compressed air, and the compressed air is jetted so as to substantially face the rotational direction of the impeller 102.

Therefore, as shown in FIG. 5B, when compressed air is injected in the direction of arrow F, the air flow in the vicinity of the inducer 104 becomes arrow Z ', and the intake air is suppressed and the surging is prevented. To be done. FIG. 2 is a block diagram of a gas turbine engine to which a surging prevention device for a compressor according to the present invention is applied.
P and the output turbine GT are directly connected by a shaft S. The shaft S is further extended to the compressor CP side and is connected to a load L which is, for example, driving wheels of an automobile.

The intake air compressed by the compressor CP is supplied to the combustor CC. In the combustor CC, the supplied fuel FF is mixed with the compressed air and burned to become combustion gas, which is expanded and worked in the output turbine GT to perform work. Emitted to the atmosphere. The rotational force generated in the output turbine GT is transmitted to the compressor CP and the load L by the shaft S, about 2/3 of the power generated in the output turbine GT is consumed by the compressor CP, and the remaining 1/3 is the driving force of the load. Becomes

An intake passage for guiding the compressed air output from the compressor CP to the combustor CC is branched midway and connected to the inlet port 201a of the three-way solenoid valve 201.
A bleed passage Ex that opens to the atmosphere is connected to the first outlet port 201b of the three-way solenoid valve 201. Further, the pressure guiding pipe 108, the chamber 109, and the disc-shaped flow path 112 are connected to the second outlet port 201c of the three-way solenoid valve 201.

FIG. 3 is a flowchart of a control routine of the three-way solenoid valve 201 executed by the control unit CNT, which is interrupted at regular intervals. In step 31, the rotational speed R of the gas turbine and the exhaust gas temperature TEX of the output turbine GT are read. Rotational speed R of the gas turbine in step 32, for example, determines a is whether rotating speed high threshold R _H less either 50,000 rpm, the exhaust gas temperature TEX proceeds to step 33 if an affirmative determination is exhausted equal to or lower than the gas high threshold T _H.

When a negative determination is made in step 32, the routine proceeds to step 34, where the gas turbine rotation speed R is, for example, 8
It is determined whether or not it is equal to or higher than the rotation speed abnormality threshold value R _{E of} 0000 rpm. When an affirmative decision is made in step 33, the operation proceeds to step 35, in which the three-way solenoid valve 201 is operated and the inlet port 201a and the second outlet port 201c are in communication, that is, the inducer recirculation flow path IR is opened. A part of the intake air compressed by the compressor CP is ejected from the compressed air ejection hole 111 to suppress the generation of vortices in the inducer 104.

When a negative determination is made in step 34, the process proceeds to step 36, and the extraction passage Ex is closed. When a negative determination is made in step 33 and when a positive determination is made in step 34, the routine proceeds to step 37, where the extraction passage Ex is opened and the inducer recirculation passage IR is closed.

FIG. 4 is a characteristic curve diagram of the compressor CP, in which the corrected intake flow rate is plotted on the horizontal axis and the pressure ratio is plotted on the vertical axis. The parameter is the corrected rotation speed. Here, Cb is a characteristic curve of a conventional compressor, and Sb is a surging line. Therefore, since the start and speed increase of the gas turbine are performed along the curve Ob, the speed increase rate must be lowered, and it takes a long time to reach the predetermined idling speed.

Further, Ca represents a characteristic curve of a compressor equipped with the surging prevention device according to the present invention, and Sa represents a surging line, which is at a position having a higher pressure ratio than the surging line Sb of the conventional compressor. Therefore, starting and speeding up of the gas turbine can be performed along the curve Oa, the speeding up rate can be increased, and the time required to reach a predetermined idling speed can be shortened.

In the above-described embodiment, the flow path that connects the chamber 109 and the compressed air ejection hole 111 has been described as a disk shape. However, at least one area is provided around the intake port 103.
It may be a tubular channel that is permanently installed. Furthermore, in the above embodiment, the compressed air is extracted from the compressor outlet, but the compressed air may be supplied from a separate compressed air source such as a pump.

Further, in the above-described embodiment, the application example to the compressor of the gas turbine has been described, but it is obvious that the present invention is also applicable to the compressor of the turbocharger, for example.

[0022]

In the surging prevention device for a compressor according to the present invention, the compressed air supplied from the compressed air source is jetted from the compressed air jet holes to suppress the generation of vortices in the inducer portion, and to suppress the surging. It is possible to suppress the occurrence of.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an embodiment of a surging prevention device for a gas turbine.

FIG. 2 is a block diagram of a gas turbine engine.

FIG. 3 is a flowchart of a three-way solenoid valve control routine.

FIG. 4 is a characteristic curve diagram of a compressor.

FIG. 5 is a development view of an impeller.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Compressor 101 ... Shroud 102 ... Impeller 103 ... Intake port 104 ... Inducer 105 ... Blade passage 106 ... Diffuser 107 ... Compressed air introduction hole 108 ... Pressure guiding tube 109 ... Chamber 110 ... Solenoid valve 111 ... Compressed air ejection hole 112 … Disc-shaped flow path 113… Swirling blade

Claims (1)

[Claims] 1. A compressor surging prevention device comprising: a compressed air source; and a compressed air injection hole for injecting compressed air supplied from the compressed air source in a direction substantially opposite to a rotation direction of an impeller of the compressor. .