DESIGN-THEORETICAL STUDY OF CASCADE CO2 SUB-CRITICAL MECHANICAL COMPRESSION / AMMONIA EJECTOR COOLING MACHINE
DOI:
https://doi.org/10.15673/0453-8307.2/2014.32596Keywords:
Ejector – Ejector refrigerating machine – Entrainment ratio – Coefficient of performance – Design characteristics – Performance characteristics – Micro-trigeneration system.Abstract
In this paper an innovative micro-trigeneration system composed of a cogeneration system and a cascade refrigeration cycle is presented. The cogeneration system is a combined heat and power (CHP) system for electricity generation and heat production. The cascade refrigeration cycle is the combination of a CO2 sub-critical mechanical compression refrigeration machine (MCRM), powered by generated electricity, and an ejector cooling machine (ECM), driven by waste heat and using refrigerant R717. Refrigerant R717 as the working fluid for ejector cooling cycle is selected in the present study. Effect of the cycle operating conditions on ejector and ejector cycle performances is studied. Optimal geometry of the ejector and performance characteristics of ECM are determined at wide range of the operating conditions. The paper also describes the theoretical analysis of the CO2 sub-critical cycle and shows the effect of the MCRM evaporating temperature on the cascade system performance. The obtained data provide necessary information to design a pilot small-scale cascade CO2 sub-critical mechanical compression / ammonia ejector refrigerating unit with cooling capacity of 10 kW for application in
micro-trigeneration systems incorporating reciprocating internal combustion engines and gas micro-turbines.
References
REFERENCES
Zaharov YU.V. Sudovye ustanovki kondicio-nirovaniya vozduha i holodil'nye mashiny. – L.: Sudostroenie, 1979. – 583 s.
Petrenko V.A. Issledovanie ezhektornoi ho-lodil'noi mashiny na freone R142. Dis... kand. teh. nauk. – Odessa, 1978.
Petrenko V.A. Princip vybora rabochego ve-schestva dlya ezhektornoi holodil'noi mashiny. // Holodil'naya tehnika i tehnologiya. – 2001. –1 (68). – S. 28-31.
Petrenko V.A., Chumak I.G. Volovik A.S. Sravnitel'nyi analiz pokazatelei effektivnosti utilizacionnoi ezhektornoi holodil'noi mashiny, rabotayuschei na razlichnyh legkokipyaschih holodil'nyh agentah // Holodil'naya tehnika i tehnologiya. – 2005. – 5 (97). – S. 25-35.
Huang B.J., Chang J.M., Wang C.P., Petrenko V. A 1-D analysis of ejector performance // International Journal of Refrigeration. – 1999. – Vol. 22. – рр. 368-378.
Ian. W. Eames, Ali. E. Ablwaifa, Petrenko V. Results of an experimental study of an advanced jet-pump refrigerator operating with R245fa // Applied Thermal Engineering. – 2007. – Vol. 27. – рр. 2833-2840.doi: 10.1016/j.applthermaleng.2006.12.009
Robinson D.M., Groll E.A. Efficiencies of transcritical CO2 cycles with and without an expansionturbine // International Journal of Refrigeration. – 1998. – Vol. 21 (7). – рр. 577-589.doi: 10.1016/s0140-7007(98)00024-3
Chen Y., Gu J. The optimum high pressure for CO2 transcritical refrigeration systems with internal heat exchangers // International Journal of Refrigeration. – 2005. – Vol. 28. – рр. 1238–1249.doi: 10.1016/j.ijrefrig.2005.08.009
Lee T.-S., Liu C.-H., Chen T.-W. Thermodynamic analysis of optimal condensing temperature of cascade-condenser in CO2/NH3 cascade refrigeration systems // International Journal of Refrigeration. – 2006. – Vol. 29. – рр. 1100-1108.doi: 10.1016/j.ijrefrig.2006.03.003
Petrenko V.O., Huang B.J., Ierin V.O. Design-theoretical study of cascade CO2 sub-critical mechanical compression / butane ejector cooling cycle // International Journal of Refrigeration. – 2011. – Vol. 34, Issue 7. – pp. 1649 – 1656.doi: 10.1016/j.ijrefrig.2010.11.012
Petrenko V.O., Huang B.J., Shestopalov K.O., Ierin V.O., Volovyk O.S. Advanced solar-assisted cascade ejector cooling / CO2 sub-critical mechanical compression refrigeration system // The proceedings of the ISES Solar World Congress. – 28 August – 2 September, 2011. – Kassel, Germany.
