ADVANCES IN HYBRID COMPRESSION TECHNOLOGY FOR ULTRALOW TEMPERATURE REFRIGERATION ACHIEVEMENT

摘要

The Hybrid Compression (HC) technology, a synergy between an Absorption Technology Section (ATS) andrna Mechanical Vapor Compression Technology Section (MVCTS), was successfully proposed recently forrnrefrigeration and heating, Staicovici (2015a, b, c). In this work, HC advances in the ultra-low temperaturernrefrigeration (ULTR), with emphasis in freeze drying applications, are disclosed. Two types thereof are inrnresearch. Both have the same ATS, but different MVCTS’s: a) 2 to 4 stage with discharge gas superheatingrnrecovery (TWRC, (Staicovici, 2014)) (HC1), and b) improved HC1 model (HC2). HC1 and HC2 are comparedrnto a standard, 2 to 4 stage and interstage cooling, MVC unit. The MVC, HC1 and HC2 model considers NH3-rnH2O and NH3, seven evaporator temperatures, T_E = −75, −70, ..., −45 ℃, three sink source temperatures,rnTss = 27, 36, and 45 ℃, and four HC technology most relevant parameters: ⅰ) MVCTS maximum dischargerngas temperature, T_(CpO); ⅱ) refrigeration coefficient of performance (COP); ⅲ) MVC vs. HC comparativerncompressed refrigerant volume, RV, and iv) exergy efficiency,η_E . Results show outstanding comparative HCrnvs. MVC and absolute values of ⅰ)-ⅳ) parameters, for same Tss and TE: A) HC1 and HC2 are compatible withrntoday compressor operation, because T_(CpO) are smaller by 50 to 170 ℃ than those of MVC; B) HC COP’s arernmuch higher than those of MVC, especially in the T_E= −75 to −60 ℃ domain, e.g. by 43 to 65 %; C) HCrnreduces R_V by 2.5 to 8 times as compared to MVC, promoting compressor physical size reduction; D) HC η_E rnhas very high values, 0.62≤η_E≤ 0.78;E) The HC2 COP, R_V and η_E values are better than those of HC1.