IL26973A - Method of transforming nuclear energy into mechanical energy and apparatus for executing said method - Google Patents

Description

C O H E N Z E D E K & S P I S B A C H E G D. PA TE NT A TT O R N E YS 24, LEVONTIN STR., P. O. B. 1169 T E L - AV I V P A T E N T S & D E S I G N S O R D I N A N C E 15991/66 SPECIFICATION A METHOD OF TRANSFORMING NUCIEAB ENERGY INTO MECHANICAL ENERGY AND APPARATUS FOB EXECUTING SAID METHOD T nt g? y s^a TPnm rpjaa n^autt rpj*y maus na^sn'? ΠΒ^Ρ NILS ANDERS LENNART WIKDAHL, a Swedish' subject, of 42, Bravallavagen. Djursholm, Sweden, HEREBY DECLARE the nature of this invention and in what manner the same is to be performed to be particularly described and ascertained in and by the following statement: The present invention relates to a method of converting energy generated by nuclear means in a steam- or gas-cooled nuclear reactor into aiechanieal energy, and also to apparatus for carrying out this method.

In the presently known methods, thermal energy is obtained in the reactor of an atomic power station, from whence it ie transported by means of a fluid through pipe lines to apparatuses outside the reactor, where it is transformed into mechanical energy, which is thereafter usually transformed into electrical energy.

As opposed to this arrangement in. the method to the invention, the production of mechanical energy takes place directly in the reactor itself in such a way that the steam or gas, utilised as the energy transfer moans in the operation of the reactor, is brought through channels, which are formed in turbine elements including thus fissile nuclear fuel. The channels are thereb arranged with /in the reactor and energy liberated by means of nuclear fission in the channels is transferred to the steam or gas. The fluid utilised for the transition of the energy is conveyed in a regular flow in appropriately arranged channels in which the flow losses can be kept very low at the same time as both a high flow velocity and a good transmission of energy can be maintained. Furthermore, in connection with the transformation of energy according to the invention an Improved efficiency is attained.

According to one aspect of the invention there is provided a method of converting nuclear energy to mecha gas and including guiding and driving turbine elements defining channels for the flow of steam or gas, at least the driving turbine elements being rotatable and at least some of the guiding and/or driving turbine elements having fissionable material incorporated therein; releasing nuclear energy from the fissionable material; directing a flow of steam or gas through said channels thereby to transfer released nuclear energy from the fissionable material to the steam or gas to provide expansion thereof, converting thereby nuclear energy to kinetic energy of the steam or gas and effecting a rotational motion of the rotatable turbine elements* According to another aspect of the invention there is provided apparatus for carrying out the above-mentioned method which includes a steam or gas turbine provided with a nuclear reactor zone including at least some of Tirhich constitute the guiding and/or driving turbine elements # &£ag the turbine channels for the flow of steam or gas and at least some of said guiding and/or driving turbine elements of the reactor zone having fissionable material incorporated therein* Embodiments of the invention will now be described with reference to the accompanying drawings, in which: Figures 1 and 2 show schematically two different apparatuses for converting nuclear energy into mechanical energy; and Figures 3 and k show respectively, longitudinal and cross-sectionsof a reactor according to the invention.

In Figure 1 the reference numeral 1 represents a steam or gas-cooled nuclear reactor, which includes a steam- or gas-turbine, mechanically connected by means of a shaft 2 to a compressor 3» which in its turn is mechanically connected by means of a shaft to an electric generator 5· The turbine 1 and the compressor 3» which latter may be arranged for compression in one or more stages, possibly with cooling between the stages, constitute together with the pipe lines 6 and 7 a closed circuit for the circulation of the fluid, i.e. steam or gas, required for the operation of the reactor, which fluid is cooled in a heat exchanger 8 of a known type to a suitable temperature before entering the compressor 3* In the turbine 1 at least a part of the elements forming -the steam- or gas-channels, preferably the vane parts of the driving or rotor element and guiding or stator element, are totally or partly made of nuclear fuel, whereby, when the reactor is in operation, energy -i-s-liberated as a result of nuclear fission is transferred to the steam or gas so that a more or less direct transformation of nuclear energy Into mechanical energy is obtained. The transformation of this energy will be more or less complete* Therefore, it might be necessary to take away a greater or smaller quantity of thermal energy from the system via the heat exchanger 8, which preferably has a capacity which can be regulated* The thermal energy, derived from this heat exchanger, can be used for example for heating purposes, possibly in connection with distillation, or for power generation* The mechanical energy obtained in the turbine 1 is used for driving the compressor 3 and also the electable generator 5 through the intermediate shafts 2 and 4. as to bring it into a critical condition at the start, at least part of the fuel elements must be capable of being brought easily into or out of their positions.

This applies first of all to those fuel elements which are not intended to be rotated durin the operation of the apparatus, but it may also be desirable or necessary for the rot tably arranged fuel elements. Besides the fuel elements contained in the turbine the reactor may also include other fuel elements arranged in the usual manner.

In order to regulate the capacity of the reactor more easily, and to render it critical, a radial flow turbine of the double-rotation type may be used. This arrangement is substantially conventional but the two rotor halves are mutually axially displaceable. In Fig. 2 which shows schematically an arrangement of this kind, the numeral 11 represents a reactor, which is built as a radial flow turbine. Each of the turbine halves is mechanically connected by means of shafts 12 to compressors 13, which are, in their turn, mechanically coupled by means of shafts lh to electric generators 15. The turbine 11 and the compressors 13 form, via pipes 16 and 17, two parallel-coupled circulation circuits for the steam or gas circulating when the reactor is in operation. These circulation circuits also include a heat exchanger 18 · In a radial flow turbine of the kind mentioned the vanes as well as the ring- and disc-elements supporting enriched uranium or other fissile nuclear fuel. In a further arrangement, an inner zone consisting of such vanes or other elements contains such fuel, whereas corresponding parts of an outer zone contains or consists of so-called fertile material* i.e. uranium-238 or thorium. In a corresponding manner the rotor and etator vane elements of an axial flow turbine in a zone situated nearer to the inlet of the turbine, may consist of or contain fissile nuclear fuel, whereas corresponding parts in a zone nearer to the outlet of the turbine may consist of or contain fertile material.

The fluid required for the operation of the reactor can, to advantage, consist of heavy water in steam form. It is, thereby, possible to profit from the comparatively low neutron capture cross-section of this fluid and from the low decrease of the neutrons per fission, resulting from the slow-down of neutrons.

Pig. 3 shows a longitudinal sectional view along the line III - ΖΠ of Pig. ¾, which in its turn is a cross-sectional view along the line IV - IV of Pig. 3· The reactor shown in these figures has a radial flow turbine of double rotation type, the rotor 19 and the stator 20 both being rotatable and being supported respectively by shafts 21, 22 passing through the reactor housing 23 and sealing means 2.4, 5 being supported by bearings 26, 27 and being each mechanically coupled with a compressor and an electric generator, not shown in igs. 3 and 4, in a manner previously described with reference to 12, 13, l4 and 15 of Pig.2. Both the rotor and the etator are provided with a number of constitutes guide vanes for the other* The steam- or gas-fluid is supplied through centrally arranged feed-channels in the shafts 21 , 22, flows radiall outwards through the channels formed by the vanes 28, and is discharged through an outlet opening 30, at the periphery of the housing 23 » which outlet opening as well as the feed-channels are connected to the closed circuits for the steam- or gas-fluid not shown in Figs. 3 and 4 into which circuits also, as shown in Pig. 2, the devices 13 and 18 are coupled. The rotor 1 on the shaft 21 is axially displaceable by means o a motor 1 and motion transmitting means 32 arranged between the motor and the shaft, in such a way that the vanes 28, 29 can be brought, either totally or partially, out of mesh with each other, whereby the amount of power that can be obtained rom the reactor may be regulated. The vanes and possibly n ■ also1 other parts of the rotor and stator and the housig 23 are made to a greater or smaller extent of nuclear fuel, which may be provided in a manner known per se, with a shell of a material to provide mechanical resistance, e.g. titanium or beryllium. It is evident that also the stator 20 with its shaft 22 may be axially displaceable in the manner above described with respect to the parts 19 , 21.

Claims (1)

1. WHAT IS CLAIMED ISi 1. A method of converting nuclear energy to mechanical energy, said method comprising the steps ofs providing a nuclear reactor turbine operated by steam or gas and including guiding and driving turbine elements definin channels for the flow of steam or gas, at least the driving turbine elements being rotatable and at least some of the guiding and/or driving turbine elements having fissionable material incorporated therein; releasing nuclear energy from the fissionable material; directing a flow of steam or gas through said channels thereby to transfer released nuclear energ from the fissionable material to the steam or gas to provide expansion thereof, converting thereby nuclear energy to kinetic energy of the steam or gas and effecting a rotational motion of the rotatable turbine elements* 2. A method as claimed in claim 1, wherein the steam or gas is in ■¾ plowed oArouit exposed to said expansion and then compressed and returned to the inlet of said nuclear reactor turbine. 3* A method as claimed in claim 2, wherein part of the turbine output is used to compress the steam or gas. k, A method as claimed in any one of claims 1 to 3i wherein the steam or gas is fed, a ter the expansion, through a heat exchanger in order to reduce its temperature* 5* A method as claimed in any one of claims 1 to , wherein heavy water in the form of steam is used for the operation of the 6, Apparatus for carrying out the method according to any one of claims 1 to 5 comprising a steam or gas turbine provided with a nuclear reactor zone Including at least some of the guiding and/or driving turbine elements defining the turbine channels for the flow of steam or gas and at least some of said guiding and/or driving turbine elements of the reactor zone having fissionable material Incorporated therein. 7· Apparatus as claimed in claim 6, in which the turbine is of the radial flow type and wherein the guiding and driving elements are mutually axially displaceable. S. Apparatus as claimed in either claim 6 or claim 7» wherein only a part of the guiding and/or driving turbine elements defining *§ie steam or gas channels, preferably the turbine elements situated nearer;: the inlet side than to the outlet side of the turbine, are composed of or contain enriched uranium or other fissile nuclear fuel* 9· Apparatus as claimed in claim 8, wherein the guiding and/or driving turbine elements defining $fee> steam or gas channels situated nearer to the outlet side of the turbine are composed of or contain fertile material 10, Apparatus for converting nuclear energy into mechanical energy substantially as described with reference to either Figure 1 or Figure 2 of the accompanying drawings. 11. Apparatus for converting nuclear energy into mechanical energy substantially as described with reference to Figure 3 a¾dt4 of the accompanying drawings. 12. A method for converting nuclear energy into mechanical energy substantially as described with reference to Figure 1, Figure 2, or Figures 3 and ¾ of the accompanying drawings. Attorneys for Applicant «