Reference

Improvement of heat pump performance using multicomponent refrigerants

Improvement of heat pump performance using multicomponent refrigerants. Final report. Mathiprakasam, B. (Midwest Res. Inst., Kansas City, MO, USA). Report, DOE/R7/01241-T1; Order No. DE84010454, 22 pp. Avail. NTIS From: Energy Res. Abstr. 1984, 9(13), Abstr. No. 24851 (English) 1982. DOCUMENT TYPE: Report CA Section: 52 (Electrochemical, Radiational, and Thermal Energy Technology) Section cross-reference(s): 48 The possibility of improving the performance of heat pumps by using binary mixts. of refrigerants was evaluated. The program consisted of 2 major activities: (1) identification of a no. of refrigerants that are suitable for heat-pump operation, collecting the thermodn. properties of these refrigerants, and coverting these data to suitable forms for prepg. computer codes, and calcg. the thermodn. properties of suitable binary mixts. formed by the refrigerants chosen; and (2) the formulation of an ideal heat-pump cycle similar to the well known vapor-compression refrigeration cycle, using binary mixts. as working fluids, the detn. of the coeff. of performance (COP) of the new cycle, and comparison of the results with those of conventional cycles using single-component refrigerants. For the heat-pump operation, R12 [75-71-8] was chosen as the main component in the binary mixt. Two compatible refrigerants, R11 [75-69-4] and R114 [76-14-2], were chosen as secondary components to be mixed with the main component. Vapor-compression cycles using the binary mixts. of refrigerants were formulated and analyzed. A computer program was prepd. to det. the COP of this cycle and several runs were made. An improvement in COP of 15-20% is achievable if multicomponent refrigerants are used in heat pumps.

Foam extrusion characteristics of low-density polyethylene

Foam extrusion characteristics of low-density polyethylene. Han, C. D.; Ma, C. Y. (Dep. Chem. Eng., Polytech. Inst. New York, Brooklyn, NY 11201, USA). Proc. - Pac. Chem. Eng. Congr., 3rd, Volume 2, 110-16. Edited by: Kim, Chul; Ihm, Son Ki. Korean Inst. Chem. Eng.: Seoul, S. Korea. (English) 1983. CODEN: 52CTAA. DOCUMENT TYPE: Conference CA Section: 38 (Plastics Fabrication and Uses) The effects of processing and material variables on extrudate swell and foam d. in the extrusion of low-d. polyethylene [9002-88-4] foam in the presence of CClF2CClF2 [76-14-2] and CCl2F2 [75-71-8] blowing agents and talc nucleating agent are discussed. Extrudate swelling on exiting the die results from the recovery of unconstrained strains, after which the growth of nucleated gas bubbles induces swelling. The extrudate swell of the homogeneous melt increases with increasing extrusion rate, while extrudate swell by bubble growth shows the opposite effect, so swelling should remain relatively const. at reasonably high extrusion rates. In extruding low-d. polyethylene contg. fluorocarbons, the usual die temp. (100-110°) is lower than the resin m.p. (~115), owing to plasticization by the fluorocarbons.