Ammonia-Lithium Nitrate Absorption Chiller with an Integrated Low-Pressure Compression Booster Cycle for Low Driving Temperatures Articles uri icon

publication date

  • March 2010

start page

  • 1351

end page

  • 1359

issue

  • 11-12

volume

  • 30

international standard serial number (ISSN)

  • 1359-4311

electronic international standard serial number (EISSN)

  • 1873-5606

abstract

  • Single-effect absorption refrigeration hybridized with mechanical vapor compression in a vapor circuit is known as the absorption cycle with an integrated booster compressor. In this study, the compressor is located
    between the evaporator and the absorber. This paper presents a numerical
    model of this cycle with ammonia-lithium nitrate solution as the
    working pair. It is based on U A - Delta T l m models for separate regions
    of plate-type heat exchangers. The results are offered as a function of
    external circuit flow parameters. Different pressure ratios of the
    compressor were tested for a wide range of hot water driving
    temperatures (55 - 95 °C), showing that low values are more beneficial.
    This cycle allows for working at lower driving temperatures than the
    single-effect cycle, with low electricity consumption. At the same
    driving temperature, the capacity is augmented with an increased
    compressor pressure ratio, thus allowing for demand matching of the
    cooling. This cycle, operating with hot water at 67 °C with a pressure
    ratio of 2.0, has the capacity of a single-effect absorption cycle at 94
    °C. The electrical COP was found to be higher than that in an ammonia
    vapor compression cycle for comprehensive working conditions.