Single-effect absorption refrigeration cycle boosted with an ejector-adiabatic absorber using a single solution pump

• A single-effect absorption refrigeration cycle, using NH3/LiNO3, is presented.
• Cycle boosted with a recirculation single solution pump, with superior performance.
• Ejector adiabatic absorber acting as a triple purpose device with variable geometry.
• This cycle allows very low temperature heat valorization.
• Increasing the recirculation allows matching the cooling capacity demand.

This paper presents a numerical model of a single-effect absorption refrigeration cycle incorporating a triple purpose liquid–vapor ejector acting as pressure booster for refrigerant vapor, adiabatic absorber and controlled solution expansion valve. The promising ammonia-lithium nitrate solution is selected as working pair, being able to produce cold at subzero temperatures, thus valid either for air conditioning or industrial refrigeration. With the use of the liquid–gas ejector, the absorption pressure becomes higher than the evaporation pressure, besides recovering part of the solution pump energy. Results of the simulation show that this innovation behaves like a compressor boosted hybrid cycle without carrying its complexity. It allows decreasing the activation temperature (about 15 °C for a recirculation ratio of 3) and increasing the cooling capacity (reaching a gain of about 100% for a generation temperature of 80 °C).