JPS61281933A - Balance testing instrument for high-speed centrifugal compressor - Google Patents

Abstract

PURPOSE:To perform a balancing test at a normal speed at an installed place of a centrifugal compressor by storing a rotor in a casing for the balancing test and making the inside of the casing vacuum and turning the rotor with a driver for the practical use. CONSTITUTION:The rotor 20 is stored in the casing 9 for the balancing test having a window 12 for attaching and detaching the balance weight and a sealing device 10 is provided to a part where a main shaft 2 of the rotor 20 is pierced. A universal joint 5 is provided to an edge of the main shaft 2 to transmit the driving force from the driver for the practical use. Then, the inside of the casing 9 is made vacuum by a depressuring means and the rotor is turned regularly by the driver to perform the balancing test. Hereby, the balancing test is made possible at the installed place and moreover, since the disassembly and assembly of the casing 9 for attaching and detaching the balance weight is unnecessary, the balancing test is performed with high precision rapidly.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention provides a balance test device for a high-speed centrifugal compressor that allows a balance test to be performed at a normal rotation speed at the installation site of a plant during periodic inspections, etc. [Conventional technology] The rotor of a high-performance, high-pressure, high-speed centrifugal compressor absorbs, for example, about 15,000 kW of shaft power, and has a normal rotational speed of about 15.00 Orpm. , this rotational speed lies between the secondary and tertiary shaft critical speeds.

In such a high-speed centrifugal compressor, unbalance may occur due to slight deformation of the impeller or bending K of the shaft due to aging, and the unbalance may need to be corrected during periodic inspection. At this time, when the normal rotational speed of the rotor is between the second and third order of the shaft critical speed, the unbalance cannot be corrected by low-speed rotation, and must be corrected in the normal rotational state.

On the other hand, when the compressor is high pressure, due to its pressure resistance, the casing is vertically split, so-called barrel type, in which the casing is assembled in the axial direction.
ab.Due to structural constraints, the attachment and detachment of the counterweight is generally done as follows:
This cannot be done externally when the compressor is properly assembled.

For this reason, conventional technology employs the field balance method, in which the vehicle is tested on-site under conditions of normal use, and the method of taking it back to the factory and testing it at the normal rotation speed.

[Problem that the invention seeks to solve]

However, in the former case, it is difficult to discover the amount of unbalance and its position, and the try-on is repeated, and the casing must be disassembled and reassembled each time, which is extremely difficult in terms of economy and construction time. On the other hand, the latter has problems with the driving engine. In other words, when driving with an electric motor, the motor is 30
Due to the constant rotation of 0.00 or 3600 rpm, it is necessary to have a very large variety of speed increasing gears. In addition, when driving with a steam turbine, the operating range is similarly limited due to critical speed, blade resonance avoidance, and strength considerations, and test equipment has been set up to be able to handle any type of compressor that has been sold in the past. In practice, it is not easy to keep it in order. In addition, in overseas plants, there are many problems in transporting rotors to and from the factory, such as the period, cost, possibility of accidents during transportation, and import/export customs clearance procedures.

As mentioned above, with the conventional balance test method, even an experienced person must carry out multiple try-ons using the field balance method, which poses problems in terms of cost and construction time, while the factory take-home method requires expensive equipment. Become. It also requires a large amount of cost.

Therefore, in the present invention, a balancing test can be performed at the location where the centrifugal compressor is installed at the normal speed,
Moreover, it is a technical problem to be solved that it is possible to eliminate the need for disassembling and assembling the casing when attaching and detaching the counterweight for unbalance correction.

[Means for solving problems]

In the present invention, a rotating portion of a high-speed centrifugal compressor is housed in a balance test casing in which a window for attaching and detaching a counterweight is formed. The casing is evacuated by a pressure reducing means such as a vacuum pump. Then, a sealing device is installed at the corresponding part of the casing through which the main shaft of the rotating part passes through, so as to maintain a vacuum state. Further, the rotating portion of the compressor is coupled to the drive machine by a universal joint. A practical machine is used for this drive machine.

[Effect]

In the above technical means, the driving force of the drive machine to which the practical machine is applied is transmitted to the rotating part of the high-speed centrifugal compressor via a universal joint, and the rotating part is normally rotated to conduct a balance test. . In this balance test, the inside of the casing is evacuated by the pressure reducing means to prevent heat generation due to windage damage when the rotating part of the compressor is rotated at high speed. The counterweight is attached and detached using a window provided in the casing.

〔Example〕

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a balance test device for a high-speed centrifugal compressor according to the present invention will be described in detail below with reference to FIG.

In FIG. 1, a rotor 20 of a high-speed centrifugal compressor, in which a plurality of impellers 1 are attached to a main shaft 2 by shrink fit or keys, is supported at the rear by bearings 3 and bearing stands 4 of a practical machine. , while the front part has a universal joint 5 and a rear bearing 6 on the drive side.
It is supported by a support stand 7. The rotor 20 is housed in a cylindrical balancing test casing 9 reinforced with a plurality of lips 8 at the compressor installation site. Furthermore, sealing devices 10 with high airtightness are provided on both sides of each location where the main shaft 2 passes through the casing 9. Although it is desirable to use the sealing device 10 of a practical device, a sealing device specifically designed for a test device may be used.

The casing 9 is provided with a tube 7 flange 1 connected to a pressure reducing means, such as a vacuum pump (not shown), and a plurality of windows 12 for attaching and detaching the counterweight.

Note that the casing 9 is divided into two on the horizontal or vertical plane.
Combined by Ranno. Further, the drive unit connected by the universal joint 5 may be a practical machine, such as a steam turbine, an electric motor, a gas turbine, or a recovery turbine. Similarly, the bearing 6 and the universal joint 5 are those of a practical machine.

Now, in the above configuration, the inside of the casing 9 is evacuated by a vacuum pump (not shown) connected to the pipe 7 runno 11. The degree of vacuum within the casing 9 may be any value necessary to prevent heat generation due to wind damage when the rotor 20 is rotated at high speed, and this state is maintained by the sealing device 10. In this state, the rotor 20 is normally rotated (by driving a practical driving machine and transmitting its driving force to the rotor 20), and a balance test is performed. In this balancing test, the counterweight can be attached and detached through the window 12.

〔Effect of the invention〕

According to the present invention, a balance test of a high-speed centrifugal compressor can be performed quickly and accurately at the installation site, and without disassembling and reassembling the casing for attaching and detaching the balance weight. In addition, the power required during regular rotation is extremely small due to only idling loss in a vacuum, and the test casing can be manufactured at a very low cost since it is a vacuum container that does not require pressure resistance.

Therefore, according to the present invention, it is possible to reduce costs, shorten the plant downtime period, and improve reliability.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a balance test device for a high-speed centrifugal compressor according to an embodiment of the present invention. 2... Main shaft, 5... Universal joint, 9... Casing, 10... Seal device, 12... Window, 20... Rotor.

Claims (1)

[Claims] A balance test casing that accommodates the rotating part of a high-speed centrifugal compressor, a window for attaching and removing the counterweight provided in this casing, and a sealing device provided in the corresponding part of the casing through which the main shaft of the rotating part passes through. and a pressure reducing means for evacuating the inside of the casing, and a universal joint for transmitting the driving force of the drive machine to the rotating part of the compressor, using a practical machine as the drive machine, and installing the compressor at the location where the compressor is installed. A balance test device for a high-speed centrifugal compressor, characterized in that the balance test is performed under normal rotation.