Optimization the panel-type heat exchangers-radiators of space power plants

Аuthors

Il’mov N. D.^*, Mavrov V. A.^**

Keldysh Research Centre, 8, Onezhskaya str., Moscow, 125438, Russia

*e-mail: ilmovdn@mail.ru
**e-mail: vasiliy.mavrov@yandex.ru

Abstract

One of the key elements of high-power nuclear power system is heat exchanger – “radiator”, designed to dump into outer space that part of the heat that cannot be turned into useful work. The panel-type radiator is relatively technological and easy to manufacture. It is a complex of finned tubes through which cooled coolant circulates. The convenient model for analyzing panel-type radiator is its presentation as simple set of parallel tubes (flows) connected by plate – two half-fins. The mathematical model is proposed on the basis of this approach, algorithms for finding optimal parameters are developed. It was found that the liquid metal coolant Na-K, despite its high thermal conductivity, does not give advantages in terms of the efficiency of the panel-type radiator compared to the diphenyl mixture. When developing the design of panel-type radiator with minimum mass, one should strive for the minimum possible thickness of the fin. In addition to mass optimization, an alternative algorithm for finding the best parameters to increase the meteoric invulnerability of panel-type radiator was proposed, when thermal power, limiting pressure loss and maximum permissible mass are specified, and solution is searched according to the highest probability that the radiator tubes do not damage because of meteoroids and particles of space debris. It is more beneficial to increase the thickness and width of the fins instead of simply increasing the thickness of the channel walls when optimized for the probability of no damage with limited mass. To improve the reliability of the panel-type radiator, it is proposed to equip each flow with shut-off valves, which will cut it off if damaged. Mathematical approaches to determine the number of damaged flows and the reliability of panel-type radiator with shut-off valves have been developed. According to the results of this work, design concept for panel-type radiator is proposed, which is distinguished by high technology and reliability.

Keywords:

radiant heat exchanger, panel-type radiator, heat-conducting radiating fin, liquid metal coolant, high-temperature organic coolants, diphenyl mixture, the probability of non-damage by meteoroids and particles of space debris

References

1. Gryaznov G.M., Pupko V.Ya. “Topaz-1” – sovetskaya kosmicheskaya yaderno-ehnergeticheskaya ustanovka [“Topaz-1” Soviet space nuclear power generation uni]. Priroda – Nature, 1991, no. 10, pp. 30–36. In Russ.

2. Sinyavskii V.V. Nauchno-tekhnicheskij zadel po yadernomu ehlektroraketnomu mezhorbital’nomu buksiru “Gerkules” [Advanced technology for nuclear electric propulsion orbital transfer vehicle “Hercules”]. Kosmicheskaya tekhnika i tekhnologii –. Space Engineering and Technology, 2013, no. 3,. pp. 25–45. In Russ.

3. Mason L.S. A Power Conversion Concept for the Jupiter Icy Moons Orbiter. AIAA-2003-6007, 2003. pp. 1–10.

4. Volkov N.N., Volkova L.I., Grigor’ev A.L., Il’mov D.N., Karevskii A.V., Mamontov Yu. N., Mironov V.V., Sobolev V.V., Filatov N.I. Raschetnoe sopostavlenie ehffektivnosti primeneniya razlichnykh teplonositelej dlya panel’nykh kholodil’nikov-izluchatelej kosmicheskikh apparatov [Comparative estimation of the effect from using different coolants in panel-type radiators of spacecrafts]. Teploenergetika – Thermal Engineering, 2018, vol. 65, no. 11, pp. 825–832. In Russ.

5. Chechetkin A.V. Vysokotemperaturnye teplonositeli [High-temperature heat exchangers]. Moscow: Energiya, 1971. 496 p. In Russ.

6. Cherkasov S.G. Asymptotic solutions in the problem of a heat-conducting radiating rib. High Temperature, 2011, vol. 49, no. 6, pp. 924–926.

7. Cherkasov S.G., Laptev I.V. Approximate analytical solution of a 2D problem for a heat conducting emitting plate. High Temperature, 2017, vol. 55, no. 1, pp. 75–78.

8. Cherkasov S.G., Laptev I.V. Priblizhennyj metod rascheta teplovogo rezhima panel’nogo kholodil’nika-izluchatelya [Simplified method for thermal mode computing of a panel-type refrigerator-radiator]. Teplovye protsessy v tekhnike – Thermal Processes in Engineering, 2018, vol. 10, no. 3-4, pp. 116–124. In Russ.

9. Borishanskii V.M., Kutateladze S.S., Novikov I.I., Fedynskii O.S. Zhidkometallicheskie teplonositeli [Liquid-metal heat exchangers]. Moscow: Atomizdat, 1976. 328 p. In Russ.

10. Wong H.Y. Handbook of Essential Formulae and Data on Heat Transfer for Engineers, Longman, London, 1977. 236 p. (Russ. Ed. Wong H.Y. Osnovnye formuly i dannye po teploobmenu dlya inzhenerov. Spravochnik. Moscow, Atomizdat, 1979. 216 p.)

11. Vargaftik N.B. Spravochnik po teplofizicheskim svojstvam gazov i zhidkostej [Handbook of thermophysical properties of gases and liquids]. Moscow: Nauka, 1972. 720 p. In Russ.

12. Mironov V.V., Tolkach M.A. Ballisticheskie predel’nye uravneniya dlya optimizatsii sistemy zashhity kosmicheskikh apparatov ot mikrometeoroidov i kosmicheskogo musora [The ballistic limiting equations for optimization of system of protection of space vehicles from micrometeorites and space garbage]. Kosmicheskaya tekhnika i tekhnologii – Space Engineering and Technology, 2016, no. 3(14). pp. 26–42. In Russ.

13. Mironov V.V., Tolkach M.A. Modeli meteoroidnoj sredy v okolozemnom kosmicheskom prostranstve i opredelenie plotnosti potoka meteoroidov [Models of the meteoritic environment in a near-earth space and definition of fluence of meteorites]. Kosmicheskaya tekhnika i tekhnologii – Space Engineering and Technology, 2017, no. 2(17). pp. 5–16. In Russ.

14. GOST 25645.128-85. Veshhestvo meteornoe. Model’ prostranstvennogo raspredeleniya [Substance meteoric. Model of space distribution]. Moscow, Standardinform Publ., 1985. 24 p. In Russ.

15. Volkov N.N., Volkova L.I., Gribkov P.V., Kushinsky A.M., Mironov V.V., Khamdamov S.S. Element ustrojstva sbrosa nizkopotentsial’noj ehnergii kosmicheskogo apparata [Element of spacecraft low-potential energy release device]. Patent RF no. 2603698, 2015.