Experimental results with a variable geometry ejector using R600a as working fluid

• Type: Article in International Scientific Journal
• Date: 2014

Authors

Paulo Pereira (Author) FEUP; Szabolcs Varga (Author) FEUP; João Soares (Author) FEUP; Armando C. Oliveira (Author) FEUP; António Lopes (Author) FEUP; Fernando Gomes Almeida (Author) FEUP; João Pedro Falcão Carneiro (Author) FEUP

Journal

Title: International Journal of Refrigeration

Vol. 46

Pages: 77-85

ISSN: 0140-7007

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 51 Citations

ISI Web of Science

Scopus - 63 Citations

Scientific classification

FOS: Engineering and technology

CORDIS: Technological sciences

Other information

Authenticus ID: P-009-VQ3

DOI: 10.1016/j.ijrefrig.2014.06.016

Abstract (EN): Experimental results with the first laboratory scale variable geometry ejector (VGE) using isobutane (R600a) are presented. Two geometrical factors, the area ratio and the nozzle exit position, can be actively controlled. The control of the area ratio is achieved by a movable spindle installed in the primary nozzle. The influence of the spindle position (SP) and condenser pressure on ejector performance are studied. The results indicate very good ejector performance for a generator and evaporator temperature of 83 degrees C and 9 degrees C, respectively. COP varied between 0.4 and 0.8, depending on operating conditions. The existence of an optimal SP, depending on the back pressure, is identified. A comparison of the benefit of applying the variable geometry design over a fixed geometry configuration is assessed. For example, for a condenser pressure of 3 bar, an 80% increase in the COP was obtained when compared to the performance of a fixed geometry ejector.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 9