SU551989A1 - Insulating wall of conduction sectionized mhd generators - Google Patents

Description

The invention relates to the MarHHTorHjvroshamamichesky (MHD) method of obtaining a scientific research institute of electric power and can be used in MHD generators, in particular, of diagonal type.

MHD generators of conduction type with diagonal conductive insulating walls and partitioned electrode walls are known, the electrode of which is either structurally combined with insulating wall modules and the frame construction of the generator, or is isolated from the latter, and the electrical circuit of the load can be different l. The diagonal wall is made of elongated (much longer than width) electrically conductive and insulated modules located at an angle, in a case, mixed to the axis of the insulating wall in the direction from one electrode wall to the Other, with which this isolator national wall.

In the end sections, the transition from the diagonal is carried out constructively

modules of the insulating wall to the non-partitioned elements of the MHD installation — the nozzle and the diffuser. The end sections are one of the most important elements of the MHD generator channel with diagonally wired necks of the insulating wall, since in large-scale MHD generators they have a length comparable with the length of the working section of the channel.

In the known MHD generators, diagonally the conductor wire of the shielding wall is made of extended modules, which are laid in the working area almost according to a single scheme, while the design of its end sections is different.

In the MHD generator, the end section of the insulating wall is made sectioned, fine-grained. This solution has the advantage that, with a sufficiently small size of the modules and their reliable isolation between themselves and from other structural elements, such a wall introduces minimal potential disturbance in the plasma and parasitic HomEHOHOHHbie currents to the wall leakage in the endpole areas are practically absent. The small-module construction is equivalent to the construction made of an insulating material, which is used in small experimental MHD generators.

However, for large-scale MHD generators, the small-section design is not technological due to the need to have an extremely large number of electrically isolated modules, requiring individual cooling, which, when using existing cooling methods using heat, also reduces the reliability of this design due to the possible leakage of the cooling system , and the necessary insulation materials for the manufacture of large structural elements capable of long m operate under conditions of high-temperature corrosive environment in the MHD-generator at high thermomechanical stresses x, Modern technology does not possess.

Also known is the insulating wall of a conductive sectioned MHD generator, which contains extended modules of electrically conductive material, insulated from one another and at an angle to the longitudinal axis of the insulating ion wall from one electrode wall to another, with which this insulating wall joins these modules in the end sections are adjacent equipotential transition elements located on the side of the input and output sections of the hardness of the MHD generator 2,

The diagonal insulating wall in the end sections on the inlet and outlet side of the channel of the MHD generator contains prtkkkikie to the extreme modules of the working section transitional non-sectional equivalent elements made of water-cooled metal on which from the firing side of the channel 6-1t a protective layer of thermal and electrostatic material is applied .

However, the existence of significant compensating currents from the plasma to the non-sectional transition element due to the impossibility of equalizing their potentials causes a decrease in the efficiency of the MHD generator and the possibility of electro-erosion destruction of the structure. In addition, at small angles of inclination of the diagonal modules to the channel axis, the length of the end sections becomes comparable with the channel length of the MHD generator, as a result of which friction and heat transfer losses increase significantly.

The purpose of the invention is to improve the efficiency of the MHD generator.

This is achieved by the fact that the insulating wall of the conduction partitioned MHD generator in the end sections is provided with at least one additional module having. V-shaped bend in the direction of the same electron wall, from which it originates.

FIG. 1 shows the insulation wall, the plan; in fig. 2 is a schematic of the frame structure of the end portion of the channel; FIG. 3 shows the layout of the modules in the well-known insulation module with the gene; 4 same in accordance with the proposed solution.

The proposed insulating wall has extended modules 1 in the working area, which are filled with electrically conductive material and isolated from each other. The modules 1 are located at an angle to the longitudinal axis of the wall in the direction from one electrode wall to another (not shown in Fig. 1) with which this insulating wall is joined. An end section adjoins the working section, equipped with at least one additional module 2, having a V-shaped bend (smoothly or at an angle) in the direction of the -th electrode wall from which it originates.

On the side of the input and output part of the channel of the MHD generator, the insulating wall has a current – to – earth transition equipotential element 3. The configuration of this element corresponds to yrv. llamas and bending directions of end modules. Each module 1 and 2 correspond to electrodes 4 to which a load 5 is connected. A longitudinal load 6 is connected to the current-to-earth equipotential transition element 3. The electrodes adjacent to the same element of the insulating wall are short-circuited with each other by an external distribution cable 7.

To implement the channel frame structure, the modules 2 of the insulating wall in the end sections are mechanically short-circuited with the corresponding electrodes 4 (see Fig. 2}. Moreover, this solution is applicable not only for frame channels with a rectangular cross section, but also for a cross section of any, for example, oval shape. A variant of the end yqaciv of the insulating wall, in which the additional modules 2 at the end part: Ke have a V-shaped bend in the direction of the electrode wall from which they take The beginning, and the row of extended modules adjacent to the additional modules m 2, are bent at the end portion towards the electrode wall opposite to the one from which they originate at the working portion, which significantly reduces the size of the transition equipotential element 3 The channel (see Figs. 3 and 4) consists of a working homogeneous section 8 and up to 1.x sections 9. The length of the ends, 1x sections in the MHD channel, can be reduced in the pre-solution for typical - - rT and LtT - conditions several hundred MW. The invention provides an increase in the efficiency of the MHD generator by relatively reducing losses in the end zones of the channel. This is achieved due to a relative decrease in the length of the end zones for a given length of the working section of the channel. In addition, there is also provided a reduction in losses associated with parasitic leakage currents from the plasma on the side insulating wall in the region of the end portions. In this case, the design of the working section of the channel MHD generator can be performed, for example, in accordance with the prototype. The invention of the insulating wall of a conduction sectioned MHD generator, comprising lengthy modules of electrically conductive material, insulated from one another and at an angle to the longitudinal axis of the insulating wall in the direction from one electrode wall to another. this insulative interface joins, and equipotential transition elements adjacent to these modules in the end sections, located on the side of the input and output sections of the channel of the MHD generator, differing from . for the purpose of pok, 1shep of the efficiency of the MHD generator, a wall in the end portions of the nerator, a wall in the end portions of G. ± G: .1 - - "- a positive module having a V-shaped bend to the side of that electrode wall he ; originates. Sources of information taken into account in the examination: LL-E-Bingoitoiee, De5-ig-h Mapcli, 1975. 2. US Patent No. 3387150, cl. 3101, 1968.

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