Résultats expérimentaux de la vaporisation d'un frigorigène hydrocarbure dans un échangeur à plaques brasées sous haute pression.

Experimental results for hydrocarbon refrigerant vaporization in brazed plate heat exchangers at high pressure.

Numéro : pap. 2106

Auteurs : DESIDERI A., SCHMIDT OMMEN T., WRONSKI J., et al.

Résumé

In recent years the interest in small capacity organic Rankine cycle (ORC) power systems for harvesting low quality waste thermal energy from industrial processes has been steadily growing. Micro ORC systems are normally equipped with brazed plate heat exchangers which allows for efficient heat transfer with a compact design. An accurate prediction of the heat transfer process characterizing these devices is required from the design phase to the development of modelbased control strategies. The current literature is lacking experimental data and validated correlations for vaporization of organic fluids at typical working conditions of ORC systems for low temperature waste heat recovery (WHR) applications. Based on these premises, a novel test-rig has been recently designed and built at the Technical University of Denmark to simulate the evaporating condition occurring in a small capacity ORC power unit. In this contribution the preliminary experimental results obtained from the first experimental campaign carried out on the rig are reported. HFC-134a was selected as working fluid. The experiments were carried out at saturation temperature of 60, 70 and 80°C and inlet and outlet qualities ranging between 0.1-0.4 and 0.6-0.95 respectively. The heat flux ranged between 19.4 and 43.1 kWm-2. The results are presented in terms of refrigerant side heat transfer coefficient and pressure drop. The heat transfer coefficient showed significant sensitivity to the saturation temperature and was characterized by a decreasing trend with respect to the mean evaporator quality. The frictional pressure drop showed a linear dependence on the mean quality value and increased as the saturation temperature decreased. The experimental heat transfer coefficients were compared with a well-known correlation for nucleate boiling which significantly underestimated the founded values.

Documents disponibles

Format PDF

Pages : 9

Disponible

  • Prix public

    20 €

  • Prix membre*

    15 €

* meilleur tarif applicable selon le type d'adhésion (voir le détail des avantages des adhésions individuelles et collectives)

Détails

  • Titre original : Experimental results for hydrocarbon refrigerant vaporization in brazed plate heat exchangers at high pressure.
  • Identifiant de la fiche : 30018962
  • Langues : Anglais
  • Source : 2016 Purdue Conferences. 16th International Refrigeration and Air-Conditioning Conference at Purdue.
  • Date d'édition : 11/07/2016

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