RU2422735C1 - Turbo-expander set - Google Patents

Abstract

FIELD: machine building. ^ SUBSTANCE: turbo-expander set consists of power external case and of internal case wherein there is installed shaft common for compressor and turbine steps. The power external case with elements of internal case whereon there are secured radial and axial supports of the shaft forms four successively arranged chambers: a chamber of gas outlet from the compressor, a chamber of gas inlet into the compressor, a chamber of gas inlet into a turbine and a chamber of gas outlet from the turbine. Axis of the shaft coincides with boring axis of the power case and is arranged vertically. The power external case is made as a single unit forming a cavity closed with a cover in its upper part. The chamber of gas outlet of the compressor step is located directly under the said cover. ^ EFFECT: raised efficiency and operability of set. ^ 2 dwg

Description

The invention relates to the field of mechanical engineering, namely to combined heating and cooling systems.

A turboexpander unit is known, including a power outer casing and an inner casing, in which a shaft common to the compressor and turbine stages is installed, and the power outer casing with elements of the inner casing forms four successive chambers: a gas inlet chamber for the compressor, a gas outlet chamber for the compressor, a chamber the gas outlet from the turbine and the gas inlet chamber of the turbine (see patent RU 2200916, class F25B 11/00, published March 20, 2003).

The disadvantages of the known device are large loads on the shaft and a relatively small critical speed.

The objective of the invention is to remedy these disadvantages. The technical result is to increase the efficiency and efficiency of the unit.

The problem is solved, and the technical result is achieved by the fact that in a turboexpander unit including a power outer casing and an inner casing, in which a shaft common to the compressor and turbine stages is installed, the power outer casing with the elements of the inner casing forms four sequentially arranged chambers: a gas outlet chamber from the compressor, the gas inlet chamber to the compressor, the gas inlet chamber to the turbine and the gas outlet chamber from the turbine, and the shaft axis, coinciding with the axis of the bore of the power casing, is located in rtikalno, wherein the outer strength housing is made in a single piece, forming a cavity closed at the top of the lid, wherein the gas discharge chamber of the compressor stage located immediately below said lid.

Figure 1 presents a cross section of the proposed unit;

figure 2 - its General view.

The turboexpander unit contains a power outer casing 1, made in the form of a single part, which forms a cavity with a cover 2 in the upper part, and an inner casing 3. In the casing 3, which is a single mounting and operating unit, a common compressor 4 and turbine 5 stages are installed a shaft 6 mounted on radial 7 and axial 8 bearings, the axis of which coincides with the axis of the bore of the power housing 1 and is located vertically. Radial 7 and axial 8 bearing bearings are fixed in the upper and lower parts of the inner housing 3. The power housing 1 with the elements of the inner housing 2 forms four chambers sequentially arranged from top to bottom in the following order: a gas outlet chamber from the compressor 9, a gas inlet chamber to the compressor 10 , a gas inlet chamber to the turbine 11 and a gas outlet chamber from the turbine 12.

The indicated arrangement of the chambers reduces heat fluxes between the steps. The fact is that the hottest gas in the turboexpander unit is the gas flow at the outlet of the compressor, and the coldest gas flow at the outlet of the turbine. If the chamber for exiting the compressor is adjacent to the chamber for entering or exiting the turbine, then the heat gain into the turbine gas through the housing and the separation walls of the chambers is maximum. This leads to a decrease in cooling capacity and, therefore, efficiency. The location of the compressor outlet chamber on the outside of the housing leads to a decrease in the supply of heat to the turbine gas and an increase in its radiation into the atmosphere, the temperature of which is lower than the temperature of the gas at the compressor outlet. The location of the gas inlet chamber of the compressor near the turbine inlet chamber interrupts the heat transfer from the compressor to the turbine.

The proposed unit operates as follows.

Gas from the pressure line enters the entrance to the turbine stage 5. As the gas expands in the turbine, its temperature and pressure decreases. Expanded and cooled gas enters the (discharge line) heat exchange or separation equipment, where the turbine generated cold is used for gas cooling technology. The power generated by the turbine goes to the drive of the kinetically associated compressor stage 4, where the gas is compressed, then it is cooled using external devices and enters the discharge line. Depending on the technological scheme used, the compressor can be located both on the inlet line and on the gas outlet line from the unit. Vertical installation of the rotor leads to a significant reduction in the load (pulsating per revolution) on the radial bearings and, therefore, allows to increase the critical speed (4-10 times compared with the horizontal installation). In addition, friction losses and energy costs are reduced, the production of radial shaft seals is reduced and its dynamics is improved (buildup). The implementation of the power casing in the form of a single part simplifies installation, as due to self-centering when inserting the inner casing, special devices are no longer needed.

Claims (1)

A turboexpander unit including a power outer casing and an inner casing, in which a shaft is installed common for the compressor and turbine stages, and the power outer casing with elements of the inner casing on which the radial and axial bearings of the shaft are mounted, forms four chambers in series: a gas exit chamber from compressor, a gas inlet chamber for the compressor, a gas inlet chamber for the turbine and a gas outlet chamber for the turbine, characterized in that the axis of the shaft coinciding with the axis of the bore of the power housing and vertically, and the power outer casing is made in the form of a single part, forming a cavity closed in the upper part by a cover, while the gas outlet chamber of the compressor stage is located directly under the specified cover.

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