[0001] 1. Field of the Invention
[0002] The present invention relates to a device for detecting operational instability during an operation of turbo compressors and, more particularly, to an instability detecting device used for easily and simply detecting a rotating stall and/or a surge frequently occurring during an operation of a turbo compressor.
[0003] 2. Description of the Prior Art
[0004] As well known to those skilled in the art, when a turbo compressor is operated in a stall region or a surge region having an insufficient amount of working fluid caused by a gradual reduction in the amount of working fluid during an operation and being lower than a predetermined reference level, the compressor undesirably experiences a rotating stall or a surge. Such a rotating stall or a surge deteriorates the operational performance of the turbo compressors, and sometimes causes serious mechanical damage or breakage of the compressors. Therefore, it is necessary to quickly and precisely detect an occurrence of such a rotating stall or a surge during an operation of the turbo compressors.
[0005] In the prior art, high-frequency pressure sensors, vibration sensors, or signal analyzing systems have been used for detecting such a stall or a surge during an operation of turbo compressors. However, the above-mentioned detecting equipments, such as high-frequency pressure sensors, vibration sensors, or signal analyzing systems typically used for detecting the rotating stall or the surge in the prior art, undesirably require the use of a complex and difficult analyzing process. Furthermore, such conventional detecting equipments are very expensive, thus undesirably increasing the installation cost, maintenance cost and repairing cost of the turbo compressors. In addition, the complex detecting equipments force operators to be highly skilled in the manipulation of the equipments. It has been thus necessary to provide a simple equipment designed to easily and reliably detect such a rotating stall and/or a surge during an operation of the turbo compressors at low cost.
[0006] Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art, and an object of the present invention is to provide an instability detecting device for turbo compressors, which easily, simply and reliably detects a rotating stall and/or a surge during an operation of such compressors while reducing the installation cost, maintenance cost and repairing cost of the compressors, different from the conventional detecting equipments, such as high-frequency pressure sensors, vibration sensors, or signal analyzing systems.
[0007] In order to accomplish the above object, the present invention provides an instability detecting device for turbo compressors, comprising: a detector consisting of: a body; first and second pressure tubes axially set in the body while parallely extending on the same plane, with first and second pressure discharge ports of the first and second pressure tubes exposed to the outside of the body at an end surface of the body; and a partition wall arranged on the end surface of the body while crossing the end surface and separating the first and second pressure discharge ports of the pressure tubes from each other, whereby the detector is attached to the inlet suction port of a compressor's impeller such that the partition wall extends in parallel to a rotation axis of the impeller, and/or to an outlet discharge port of a compressor's impeller such that said partition wall extends in parallel to a discharge flow from impeller, the detector thus sensing a pressure difference between the first and second pressure discharge ports of the pressure tubes and detecting an operation of the compressor within an unstable operational region.
[0008] In the instability detecting device, the detector may be connected to a monitor allowing an operator to know operational conditions of the compressor so as to detect an operation of the compressor within the unstable operational region.
[0009] In addition, the detector may be provided with a means for alerting the operator of an operation of the compressor within the unstable operational region.
[0010] When the turbo compressor is operated within a stable operational region, the working fluid flows along the partition wall prior to being introduced into the suction port of the impeller and/or into the discharge port, and so any pressure difference between the first and second pressure discharge ports of the pressure tubes is not detected. However, when the compressor is operated within an unstable operational region to form a rotating stall and/or a surge, the working fluid flows in a direction perpendicular to the partition wall prior to being introduced into the suction port of the impeller, and so a pressure difference between the first and second pressure discharge ports of the pressure tubes is detected. It occurs also if the detector is introduced into the discharge port of the impeller.
[0011] The detected pressure difference is applied to a U-shaped pressure tube, or is converted into an electric signal prior to being displayed on the monitor, thus allowing an operator to be informed of an operation of the compressor within the unstable operational region. The detecting device of this invention also alerts the operator of the operation of the compressor within the unstable operational region through a visual signal or a voice signal.
[0012] The above and other objects, features and other advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:
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[0021] Reference now should be made to the drawings, in which the same reference numerals are used throughout the different drawings to designate the same or similar components.
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[0023] As shown in the drawings, the instability detecting device for turbo compressors of this invention includes a detector
[0024] In order to accomplish the desired operational performance, the instability detector
[0025] Each of the two pressure tubes
[0026] As shown in
[0027] During an operation of the impeller
[0028] As shown in the graph of
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[0030]
[0031] As shown in
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[0033] The instability detecting device of this invention detects the pressure difference between the two pressure discharge ports
[0034] In addition, the detector
[0035] In the preferred embodiment of this invention, the instability detector
[0036] As described above, the present invention provides an instability detecting device for turbo compressors. This detecting device has a simple construction, thus being easily and simply produced at low cost. The detecting device of this invention is not an electric or electronic equipment having a complex construction, and so it is easily and simply operated, maintained and repaired at low cost, thus being convenient to an operator. Furthermore, this detecting device has a high operational reliability.
[0037] The detecting device of this invention is easily operated even by an unskilled operator, and is usable with a conventional turbo compressor regardless of the capacity, size and rotational speed of the compressor. The detecting device does not have any ill-effect on the operational performance of the turbo compressors.
[0038] The instability detecting device of this invention allows an operator of a turbo compressor to easily monitor the operational conditions of the compressor, thus allowing the operator to effectively control the operation of the compressor.
[0039] When the instability detecting device of this invention is used with a conventional operation control system for turbo compressors, it is possible for the detecting device to quickly inform an operator of an unstable operation of the compressor, thus allowing the operator to quickly control the operation of the compressor to restore a stable operation. Therefore, the detecting device of this invention almost completely prevents a reduction in the operational performance of the turbo compressors, and protects the compressors from severe damage or breakage during an operation.
[0040] Although a preferred embodiment of the present invention has been described for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims.