Autostructurizing solid phase of a refrigerant as a multi-functional low-temperature unit of a cooler Alexander Dvornitsyn a , Vjacheslav Naer b , Andrey Rozhentsev b, * a Technology Research Institute ‘NIITKriogenmash’, Promyshlennaya Str. 1, 65031 Odessa, Ukraine b Odessa State Academy of Refrigeration, Dvorjanskaya Str. 1/3, 65026 Odessa, Ukraine Received 15 October 2003; received in revised form 16 March 2004; accepted 19 March 2004 Abstract It has been shown that under certain conditions the solid phase of a refrigerant with a peculiar internal capillary-porous structure can be formed in the working circuit of a refrigerating machine. That solid porous phase does not cease circulation of the refrigerant and possess a unique ability to bring its dimensions and internal structure in correspondence with internal and external heat flows that turns it at once into an auto-adjusted combined ‘throttling-heat exchanging’ unit of the refrigerating machine. The discovered effect opens a prospect of new advanced technologies developing in the field of refrigeration engineering and cryogenics. q 2004 Elsevier Ltd and IIR. All rights reserved. Keywords: Refrigerant; CO 2 ; Solidification; Sublimation; Refrigerating system; Expansion; Heat transfer L’autostructuration de la phase solide d’un frigorige`ne utilise´ comme e´le´ment basse tempe´rature d’un refroidisseur Mots-cle´s: Frigorige`ne; CO 2 ; Solidification; Sublimation; Syste`me frigorifique; De´tente; Transfert de chaleur 1. Introduction There are technical devices where in the operating lines a flow of the working substance undergoes substantial thermal and pressure changes followed by the gradual phase transitions ‘liquid–solid–vapor’ [1]. The elementary drawing of such flow is shown in Fig. 1. The peculiar feature of that flow is that, the solid phase of the working substance, forming on a porous gas- permeable surface, does not lead to circulation cessation of the working substance in the line. The given dynamic system is stable both in time and in space. By this it is meant that the phase transitions chain in the working substance flow exists for some considerable period of time and maintains fully sequential space division (sharply defined phase boundaries), as one can see in Fig. 1. Some descriptions of the formation and long-term operation of similar systems are presented in Refs. [1–3]. A practical example of a device of this kind could be the so-called cryogenic carbon dioxide bottle-sublimation cooler (Fig. 2). A detailed technical description of that cooler is presented in Refs. [2–4]. We shall not mention the principles of the cooler operation especially since they will be clarified in the course of experimental data analysis presented below. Here we should only note that an original technological approach has enabled to organize in the low- temperature chamber of that cooler the processes of crystallization, throttling, sublimation and regenerative heat exchange running simultaneously and as long as it is International Journal of Refrigeration 27 (2004) 484–491 www.elsevier.com/locate/ijrefrig 0140-7007/$35.00 q 2004 Elsevier Ltd and IIR. All rights reserved. doi:10.1016/j.ijrefrig.2004.03.014 * Corresponding author. E-mail address: dolphin@te.net.ua (A. Rozhentsev).