RU2140675C1 - Dual-function space nuclear power plant - Google Patents

Abstract

FIELD: nuclear power systems for space engineering. SUBSTANCE: power plant has thermionic conversion power reactor with core functioning as heat source and direct heat-to- electricity converter, as well as reactor cooling system in the form of circulating loop with radiating cooler, pumping unit, and coolant pipelines. Newly introduced additional heat-to- electricity converter is mounted beyond thermionic reactor core and has delivery pipeline connected to pipeline section running between thermionic reactor and radiating cooler, discharge pipeline connected to pipeline section between radiating cooler and pumping unit, additional system for releasing heat not converted in thermodynamic cycle of additional converter, and device that functions to convey coolant flow from thermionic reactor to additional converter. Thermoelectric or thermionic converter, motor-generator set built around Rankine-, Brayton-, or Stirling-cycle steam or gas machines, and regenerative electrochemical generator may be used as additional converter. Power plant can be used to convey space vehicles including information ones to stationary and, primarily, geostationary orbit to feed space vehicles for long period of 10 to 15 year. EFFECT: improved service life at low power requirement. 5 cl, 2 dwg

Description

 The invention relates to nuclear energy and space technology and can be used to create space power and propulsion systems.

 Currently, the most likely area of application for space nuclear power plants (NPPs) is to use them to solve two interrelated tasks: to deliver spacecraft (SC), and above all information, to the orbit of operation, mainly geostationary (GSO), and subsequent long within 10 - 15 years of power supply of spacecraft equipment. Thus, the nuclear power plant will provide a solution to space problems, sufficiently prepared for technical implementation. A resource of 10 to 15 years is essential to ensure competitiveness with respect to solar photovoltaic converters.

 Known space nuclear power plant with thermionic reactor-converter (TRP) "Topaz" - Kuznetsov VA, Gryaznov GM, Artyukhov G.Ya. et al. Development and creation of a thermal emission nuclear power plant "Topaz", Atomic Energy, 1974, v. 36, no. 6, p. 450 - 454. It contains TRP based on thermal neutrons, radiation protection, a cooling system with a coolant in the form of a NaK eutectic alloy, a control system, and a supporting structure. TRP contains an active zone (AZ), consisting of a moderator and thermionic power generating assemblies, usually called thermionic power generating channels (EGC), a reflector in which the controls are in the form of rotary drums.

 Such a nuclear power plant with TRP successfully worked out in space, generating an electric power of about 5 kW for about a year to power the spacecraft equipment. However, this nuclear power plant cannot be used as a dual-purpose (dual-mode) installation for powering not only the spacecraft equipment, but also the electric propulsion system (ERP), both because of the low level of electric power and because of the relatively low resource.

 A space nuclear power plant with TRP as a source of electric power for electric propulsion is known for transport operations to deliver the Martian expeditionary complex to Mars and return the expedition to Earth. Ageev V.P. et al. Energy block based on a thermionic nuclear electric propulsion system for the Martian expeditionary complex, scientific and technical collection. Vol. 1 (134) RD and EI. Ed. NIITP, 1992, p. 25 - 33. It contains TRP on fast neutrons with a slowing reflector, the active zone of which is composed of highly efficient EGCs; radiation protection; combined reactor control system; cooling system TRP of the circulation circuit with a lithium coolant and a refrigerator-emitter based on heat pipes, made in the form of hydraulically independent modules. The electric power of such a nuclear power plant is from 2.5 to 15 MW (depending on the expedition scheme) and the resource is 12000 hours.

 Such a nuclear power plant is capable of providing power to the electric propulsion system for delivery to Mars of an expeditionary complex weighing about 150 tons and returning to the Earth a return ship to Earth weighing 10 tons with a total expedition time of no more than 1.5 years. However, such a nuclear power plant, designed for high specific characteristics and relatively low resource, cannot be used for long-term power supply of spacecraft equipment.

 The closest analogue of the invention is a dual-mode space nuclear power plant, Sukhov Yu.I., Sinyavsky V.V. Overview of the work of RSC Energia named after S.P. Queen of thermionic nuclear power plants of high power for space applications. Scientific tech. Sat Rkt. Proceedings of RSC Energia named after S.P. Queen. Series 12, Vol. RSC Energia, Kaliningrad, Moscow. Region, 1995, Vol. 3 - 4: Cosmic thermionic emission nuclear power plants and electric propulsion systems of high power, part I, p. 20 - 24. It is intended for dual-use in the nuclear power unit (NED): for powering the electric propulsion system and for transport operations and for powering the onboard equipment of the payload of the information spacecraft on the GSO. A nuclear power plant contains TRP on fast neutrons with a slowing reflector, radiation protection; combined reactor control system; circulation cooling system TRP, consisting of pipelines with lithium coolant, an electromagnetic pump with a refrigerator-emitter based on heat pipes, made in the form of hydraulically independent modules. The TRP core is composed of EGCs, the hardened doped tungsten single crystal used as emitter shells of which. The electric power of the nuclear power plant in the transport mode is 100 - 150 kW with a resource of up to 1.5 years; NPP power in the power supply mode of the spacecraft equipment 10-40 kW with the claimed resource up to 10 years. Both operating modes of the nuclear power plant are provided due to the operation of the TRP in two modes: at the nominal (transport) mode with the maximum power level and in the mode of reduced thermal and, therefore, electric power.

 However, the creation of such a dual-mode nuclear power plant with a long operating mode is associated with significant difficulties and, above all, with the need to create a dual-mode EGC for a long life. Usually, an EGC is created for only one operating mode, when its parameters, including the geometric dimensions and the amount of EGE in the EGC, can be selected optimal for this mode. The operation of an EGC in any other thermal power mode will not be optimal, the temperature fields in one of the modes will be substantially uneven, which in principle casts doubt on the possibility of creating an EGC that can operate for a long time in two significantly different modes. In addition, the current – voltage characteristics of EGCs as an autonomous energy source are “soft”, i.e. operating current and voltage depend on thermal power, so each mode will have its own operating voltage, which will complicate the operation of such a nuclear power plant. A long-term TRP resource will require the creation of a new methodology for working out EGCs during loop reactor tests on a shortened time base.

 The technical result achieved by using the invention is to ensure that the nuclear power plant can operate in two modes that differ significantly in electrical power and resource with an increase in operating life at a reduced power level and an increase in the quality of nuclear power plant working under ground conditions.

 The specified technical result is achieved due to the fact that in a dual-mode space nuclear power plant containing TRP as a heat source and a thermal energy converter directly into electrical energy, the TRP cooling system in the form of a circulation circuit with a refrigerator emitter (CI), a pumping device, and pipelines with a coolant, comprising sections from TRP to CI, from CI to a pumping device and from a pumping device to a TRP, an additional thermal energy converter placed outside the TRP is introduced into an electric one, equipped with a supply pipe connected to a pipeline section from a CI to a CI, a discharge pipe connected to a pipe section from a CI to a pumping device, an additional system for removing the untransformed heat of the thermodynamic cycle of the additional converter and a device that switches the heat carrier flow from the fuel dispenser to the additional converter, moreover, the connection node of the supply pipe can be made in the form of a two-position switching device .

 Space NPS can be made modular, i.e. in the form of at least 2 subsystems, each of which contains a part of the TRP core, enclosed in a sealed circuit, a section of the refrigerator-emitter, a pumping device and pipelines with a coolant, as well as an additional converter of thermal energy into electrical energy, a supply pipe connected to the site pipeline from TRP to CI, a discharge pipe connected to a section of the pipeline from CI to a pumping device, a system for removing untransformed heat of the thermodynamic cycle of additional eobrazovatelya and apparatus by switching coolant flow to additional TRP converter to a node connecting the supply pipe.

 As an additional converter, a thermoelectric converter of thermal energy into electrical energy can be used; thermionic converter of thermal energy into electric; an electric machine generator based on steam or gas engines operating on the Rankine, Brighton or Stirling cycle; regenerative electrochemical generator. As a system for removing the untransformed heat of the thermodynamic cycle of the additional converter, both the main CI and the additional refrigerator-radiator can be used.

 In FIG. 1 shows a diagram of a space dual-mode nuclear power plant, and in FIG. 2 - its option.

 The dual-mode space nuclear power plant contains a TRP 1, consisting of an active zone (AZ) 2 and a reflector 3, between which a sealed housing 4 can be placed. AZ 3 is assembled from EGC 5, which are externally cooled by a heat carrier, for example, a NaK or Li eutectic alloy. The coolant inlet in the AZ 2 is carried out through the pipe 6, and the drain through the pipe 7. The coolant in the cooling system is circulated by a pumping device 8, usually made in the form of an electromagnetic pump. The heat that has not been converted into TRP is discharged by radiation into space from the surface of CI 9, made, for example, on the basis of heat pipes 10. The cooling system of the TRP 1 also includes a pipeline from TRP 1 to CI 9 in the form of two sections 11 and 12 separated by a switching device 13 , and the pipeline 14 from CI 9 to the switching device 8, and the pipeline 15 from the pumping device 8 to the TRP 1.

 Outside TRP 1 there is an additional converter 16 of thermal energy into electrical energy. As an additional Converter 16 can be applied thermoelectric Converter of thermal energy into electrical energy; thermionic converter of thermal energy into electric; an electric machine generator based on steam or gas engines operating on the Rankine, Brighton or Stirling cycle, a regenerative electrochemical generator. The additional Converter 16 has a heat supply system 17, equipped with a supply pipe 18 connected to a portion of the pipeline between the TRP 1 and CI 9 at the installation site of the device 13, switching the flow of coolant (switching device), and a discharge pipe 19 connected to the portion of the pipe 14 from CI 9 to the switching device 8. The flow of the heated coolant from the TRP 1 is switched to the heat supply system 17 of the additional converter 16 through the switching device 13, which can be l is made in the form of a two-position switching device. The additional converter 16 has an additional system for removing the untransformed heat of the thermodynamic cycle of the additional converter, made, for example, also in the form of a circulation circuit with a heat sink 20, with an additional pumping device 21, for example an electromagnetic pump, and sections 22 and 23 of the pipeline from the additional converter to CI and from CI to additional converter, respectively. As the CI of the system for removing the non-converted heat of the thermodynamic cycle of the additional converter, both the main CI with TT 10 (Fig. 1) can be used, and the additional CI 24 can be used, for example, also based on TT 10 (Fig. 2).

 In the reflector 3 controls TRP 1 are placed in the form of rotary cylinders 25 with neutron-absorbing pads 26.

 TRP 1 and additional Converter 16 are equipped with terminals 27 and 28, respectively, for the removal of generated electricity to consumers or the distribution system of electricity (Fig. 1 and 2 are not shown).

 Space dual-mode nuclear power plant operates as follows.

 In the initial state, the rotary cylinders 25 of the TRP 1 are in position with absorbing plates 26 to the AZ 2. Therefore, the TRP 1 is not critical, and in this state the space nuclear power plant is launched into space. In a radiation-safe orbit, for example, with a height of 500 - 800 km, a nuclear power plant is launched. To do this, automatically, on command from the Earth or the control system of the nuclear power plant (or spacecraft), the rotary cylinders 25 are turned so that the pads 26 extend from the AZ 2. The fission reaction of the fuel material in the cores of the EGC 5 begins. The heat released in the EGC 5 is removed from the AZ 2 the coolant of the main circuit, which through the pipe 7 and the pipe section 11, the switching device 13 and the pipe section 12 enters the heat exchanger of the evaporation zones TT 10 CI 9. In CI 9, heat is released by radiation into space . Cooled in CI 9, the coolant through section 14 of the pipeline enters the pumping device 8, which, creating a pressure, pumps the coolant through section 15 and pipe 6 into the active zone 2 TRP 1.

 After reaching the working level of thermal power, the working fluid (cesium vapor) is supplied to the interelectrode gaps of EGC 5 and they begin to generate electricity. Electricity is dissipated to the consumer using isolated current leads 27. The unconverted heat of the thermodynamic cycle is dissipated by the heat carrier similarly to that considered above in the start-up mode and then is discharged into space by radiation in CI 9. In this case, the switching device 13, made, for example, in the form of a two-position valve, occupies a guiding position coolant in CI 9. The surface of CI 9, as well as the flow rate and heating of the coolant can be chosen optimal to obtain the required electrical power per th mode of operation, such as transport, when the generated power is consumed to power electric propulsion system (electric propulsion). Moreover, the additional generator 16 does not work, since heat from the TRP 1 is not supplied to it.

 After the NPP has finished its work in the first mode, for example, transport (spacecraft delivery with the help of electric propulsion systems to the orbit of the spacecraft’s functioning, for example, geostationary), the nuclear power plant should be transferred to the second mode of operation, for example, to power spacecraft equipment with a lower power level, but with a significantly longer resource. For this, the level of thermal power of the TRP 1 is reduced, the switching device 13 is transferred to the position when the heat carrier flow from the active zone 2 of the TRP 1 is sent through the pipe section 18 to the additional converter 16. In the converter 16, this heat is converted to electricity, which using terminals 28 allocated to the consumer of electricity, such as spacecraft equipment. The coolant cooled in the additional generator 16 through the pipeline section 19 enters the pipeline section 14, then into the pumping device 8 and through the pipe section 15 and the pipe 6 to the TRP core 2 1. Heat not converted in the additional converter 16 using an additional cooling system, for example, in the form of an additional circulation circuit with sections of the heat sink 20, with sections 22 and 23 of pipelines and an additional pumping device 21 is transferred to CI 9 or to an additional CI 24, where asyvaetsya radiation into space.

 Since the thermal power of EGC 5 of the second mode has become less than it was in the first mode, EGC 5 cease to generate electricity and in the second mode of operation are used only as heat sources for an additional generator 16. It is possible to ensure authorized shutdown of EGCs as sources of electricity, for example, for due to the removal of the working fluid (cesium vapor) from the MEZ EGC 5.

 The working life of the EGC as a heat source is significantly higher than the source of electricity, since in this case such main reasons for limiting the life of the EGC, such as swelling of the core fuel composition with deformation of the emitter shell to short-circuit the electrodes and electrical breakdown of the collector package, will not affect the possibility of operation EGC as a conventional fuel element (fuel element) of a nuclear reactor.

 Thus, the invention provides the possibility of operating a space nuclear power plant in two modes that differ significantly in electrical power and resource with an increase in the operating resource at a reduced power level. At the same time, an improvement in the quality of working out a dual-mode nuclear power plant under ground conditions is achieved, since an additional converter with a long service life can be worked out under bench conditions with electric heating, and thermionic EGCs as sources of electricity can be worked out in loop reactor tests for a relatively short life.

Claims (5)

 1. A dual-mode space nuclear power installation containing a thermionic reactor with an active zone as a heat source and a thermal energy converter directly into electrical energy; a reactor reactor cooling system in the form of a circulation loop with a radiator, a pumping device, and pipelines with a coolant with sections from the reactor-converter to the refrigerator-emitter, from the refrigerator-emitter to a pumping device and from pumping its device to the reactor-converter, characterized in that an additional converter of thermal energy into electric energy, located outside the reactor-converter, is introduced, provided with a supply pipe connected to a pipe section from the converter reactor to a radiator-radiator, a discharge pipe connected to a pipe section from the refrigerator -radiator to the pumping device, an additional system for removing untransformed heat of the thermodynamic cycle of an additional a converter and a device switching a heat carrier flow from a converter reactor to an additional converter.  2. A dual-mode space nuclear power installation according to claim 1, characterized in that a thermoelectric converter of thermal energy into electrical energy is used as an additional converter.  3. The dual-mode space nuclear power installation according to claim 1, characterized in that a thermionic converter of thermal energy into electrical energy is used as an additional converter.  4. The dual-mode space nuclear power installation according to claim 1, characterized in that an electric converter made on the basis of steam or gas engines operating according to the Rankine, Brighton, or Stirling cycle is used as an additional converter.  5. The dual-mode space nuclear power plant according to claim 1, characterized in that a regenerative electrochemical generator is used as an additional converter.

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