WES is engineered to provide solutions for complex engineering problems. We try to achieve this through innovation, design, development, and manufacturing practices to achieve the quality desired by design. As a part of our endeavour to produce quality products, we are delighted to introduce, The Phoenix – an innovative expander which can generate power in pressure let-down scenarios in process industries.
Process industries use pressure-reducing valves to reduce steam pressure from its generation pressure in the boiler to usage pressure near process application. The process in PRV is thermodynamically irreversible throttling which generates entropy leading to a reduction in the exergy of steam. This lost exergy can be recovered if expansion is done instead of throttling.
Using turbines, especially impulse turbines, would be challenging considering their erosion potential. There are commercially available turbine options, but they all have compromised designs to tackle the erosion problem leading to poor peak isentropic efficiency, typically around 45%. Turbines with a low number of nozzles give poor isentropic efficiency in part loading. The variation in steam load in many process industries demands part loading of the expander. Hence turbine usage is not recommended in process industries with saturated steam and variation in steam demand.
Positive displacement expanders can handle wet steam better than turbines due to their low inlet velocity. The reciprocating expander has superior isentropic efficiency but has limitations in its reliability and issues associated with mixing oil and water. The reliability issue in reciprocating is absent in the screw expander due to the relatively low number of components. Though both these expanders can handle wet steam, their part load efficiency is poor, reducing overall power output in industries with variable steam demand. EnERG lab IITM has developed (Through a project funded by DST, Govt of India) an expander capable of overcoming these challenges.
This expander (Phoenix) has inbuilt design features, enabling it to operate at high isentropic efficiency of ~80% in full load and part loading. The unique mechanism used in this expander is patented. Compared with reciprocating expanders, Phoenix is expected to have improved reliability owing to its lower number of components. A phoenix’s size and weight are roughly half compared to reciprocating expanders with similar power output.