Abstract
The choice of energy recovery technology in process industries is still a matter of debate despite the two state-of-art methods, namely turbine expanders and variable speed pumps, available in the market.
The paper enables a theoretical model to define different performances indices for both techniques. A heat exchanger problem operating with incompressible fluids is selected as the general process application and simplified to single and multiple processes for clearer interpretation.
The investigation finds the need for the two expanders, one across the throttle (traditional) and the other across the combined throttle-process unit (novel) for enhanced recovery potential. Variable speed pumps would be better than twin expanders in single processes, but not in multiple processes that form backbone of process industries.
The decisive outcome particularly for multiple process application revealed the need to innovate by combining both the technologies where the throttle expander for each elemental process is hybridized with the variable speed feed pump.
The study concludes that the use of two recovery technologies would be inevitable in industrial processes and proposes a series of recommendations for its realization, which include better knowledge of load duration of processes, using throttle-expander units, carrying out cost-benefit analysis and developing favorable policies.
