ANALYSIS AND DATA PROCESSING SYSTEMS

The conventional district heating system in Russia has a number of disadvantages associated with a high temperature of the network water, large heat losses and increased wear of heating mains. The removal of these disadvantages is possible by lowering the direct network water temperature and switching to a combined heat supply system. In the article a heat and power plant with a gas network heater (GNH) and freonthermal transformer (FTT) is considered as such a system. Thermodynamic and design characteristics of a thermal transformer as an element of a combined heat supply system affect the operation of the heat and power plant and the parameters of a heat supply system for consumers. Market-leading low-boiling working fluids (LWF) R134a, R404a, R600a were considered as a working medium of FTT. The area of the heat-exchanging surface of the evaporator, of the condenser and of the elementwise capital investment in the FTT are determined for each of them, Modern market conditions are characterized by changes in the pricing policy; therefore, three options for investment in FTTs with an increase in the cost of FTT elements and LWFs are examined in the article. The influence of investment options on the technical and economic efficiency of heat and power plant operation with GNH and FTT is shown taking into account the change in the heat load of the power unit. Also, the technical and economic efficiency is compared with the efficiency of a traditional heat supply system. The conclusions reveal high surface areas of the condenser and the FTT evaporator and FTT high capital investment when it operates using the R600a working fluid. The transition from a traditional heat supply system to a heat and power plant with GNH and FTT with an increase in the cost of FTT elements is 50% less economical for heating units with a 250 MW turbine, and two times less efficient for power units with all versions of thermal turbines.

1. Slavin V.S., Danilov V.V. Povyshenieeffektivnostisistemytsentralizovannogoteplosnabzheniyanaosnoveprimeneniyatekhnologiiteplovykhnasosov[Increasing the efficiency of the district heating system based on the use of heat pump technology]. Energosberezhenieivodopodgotovka – Energy Saving and Water Treatment, 2000, no. 2, pp. 6–13.

2. Filippov S.P. Razvitietsentralizovannogoteplosnabzheniya v Rossii[Development of district heating in Russia].Teploenergetika – Thermal Engineering, 2009, no. 12, pp. 2–14.(In Russian).

3. Novozhilov Yu.N. Primenenieteplovykhnasosov v skhemakhteplosnabzheniya[Thermocompressor in heat supply circuit].Promyshlennayaenergetika – Industrial power engineering, 2006, no. 5, pp. 24–25.

4. Andryushchenko A.I. Sravnitel'nayaeffektivnost' primeneniyateplovykhnasosovdlyatsentralizovannogoteplosnabzheniya[Comparative efficacy of heat pumps for district heating].Promyshlennayaenergetika – Industrial power engineering, 1997, no. 6, pp. 2–4.

5. Petrushkin A.V. Effektivnost' kombinirovannykhsistemteplosnabzheniya.Avtoref.diss. kand. tekhn. nauk [The efficiency of combined heat supply systems. Author's abstract of PhDeng. sci. diss.]. Saratov, 1998.18 p.

6. Morosyuk T.V. Modeling selection of a heat pump integrated with a power unit. Chemical and Petroleum Engineering, 1999, vol. 35, pp. 166–169.

7. Borodikhin I.V. Issledovanieeffektivnostiioptimizatsiyaparametrov TETs v kom-binirovannoisistemeteplosnabzheniya s DVS.Avtoref.diss. kand. tekhn. nauk [Research of efficiency and optimization of CHP parameters in the combined heat supply system with ICE. Author's abstract of PhDeng. sci. diss.].Novosibirsk, 2004.20 p.

8. Grigorieva O.K., Frantseva A.A., Nozdrenko G.V. Sistematsentralizovannogoteplosnabzheniya[District heating system]. Patent RF, no. 110459, 2011.

9. Saleh B., Koglbauer G.,Wendland M., Fischer J. Working fluids for low-temperature organic Rankine cycle. The International Journal Energy, 2007, vol. 32, no. 10, pp. 1201–1221.

10. Obzorkhladagentov[Refrigerant overview]. 13^th ed. Available at: http://s-holod72.ru/wp-content/uploads/2013/12/Review_refrigerant.pdf (accessed 17.09.2018).

11. Babakin B.S., Stefanchuk V.I., Kovtunov E.E. Al'ternativnyekhladagentyiserviskholodil'nykhsistemnaikhosnove[Alternative refrigerants and servicing of refrigeration systems based on them].Moscow, Kolos Publ., 2000. 160 p.

12. Martin J.J., Hou Y.C. Development of an equation of state for gases.AIChE Journal, 1955, vol. 1, no. 2, pp. 142–151.

13. Altunin V.V. Metodsostavleniyauravneniyasostoyaniyareal'nogogazapoogranichennomukolichestvuiskhodnykhopytnykhdannykh[The method of compiling the equation of state of a real gas from a limited number of initial experimental data]. Teploenergetika – Thermal Engineering, 1962, no. 3, pp. 72–78.(In Russian).

14. Perel'shtein I.I. Issledovanietermodinamicheskikhsvoistvkholodil'nykhagentov[Investigation of the thermodynamic properties of refrigeration agents]. Moscow, Gosizdat Publ., 1962. 62 p.

15. Grigorieva O.K. Kompleksnoeissledovanie PGU pyleugol'nykh TETs s gazovymisetevymipodogrevatelyami.Diss. kand.tekhn. nauk [Complex research CCGT coal-fired thermal power station with gas network heaters. PhD eng. sci. diss.].Novosibirsk, 2005.124 p.

16. Frantseva A.A. Optimizatsionnyeissledovanie TES s gazosetevympodogrevatelemifreonovymitermotransformatorami.Diss. kand.tekhn. nauk [Optimization studies of the heat and power plant with gaz-net heater and freonthermotransformers. PhD eng. sci. diss.]Novosibirsk, 2015.111 p.

17. Golubeva L.F., Grigorieva O.K., Frantseva A.A. Primeneniefreonovykhtekhnologiinateplovykhelektricheskikhstantsiyakh[The application of Freon technologies at heat power stations]. NauchnyivestnikNovosibirskogogosudarstvennogotekhnicheskogouniversiteta – Science bulletin of the Novosibirsk state technical university, 2016, no. 4 (65), pp. 164–174.doi: 10.17212/1814-1196-2016-4-164-174.