论文简介 |
The ejector refrigeration integrated in the air-conditioning system is a promising technology, because it
could be driven by the low grade energy. In the present study, a theoretical calculation based on the real
gas property is put forward to estimate the ejector refrigeration system performance under overall modes
(critical/sub-critical modes). The experimental data from literature are applied to validate the proposed
model. The findings show that the proposed model has higher accuracy compared to the model using the
ideal gas law, especially when the ejector operates at sub-critical mode. Then, the performances of the
ejector refrigeration circle using different refrigerants are analyzed. R290 and R134a are selected as typical refrigerants by considering the aspects of COP, environmental impact, safety and economy. Finally,
the ejector refrigeration performance is investigated under variable operation conditions with R290
and R134a as refrigerants. The results show that the R290 ejector circle has higher COP under critical
mode and could operate at low evaporator temperature. However, the performance would decrease
rapidly at high condenser temperature. The performance of R134a ejector circle is the opposite, with relatively lower COP, and higher COP at high condenser temperature compared to R290. |