Technology Outline (Process Description)

Process industries using steam for heating, typically generates steam at a higher pressure than its usage. This pressure reduction is done through a pressure-reducing valve (PRV) by throttling, which is thermodynamically irreversible. The option of the expander to reduce this irreversibility has been explored previously but with limited success. This could be due to the unique challenges present in process industries, such as wetness in admission steam and the variable nature of steam flow demand, which reduces the efficiency of expander due to part loading. In order to overcome these, a Wankel based expander was developed at IIT Madras, with dynamic volumetric control mechanism (patent No. US 11448073 B2). This technique is used to dynamically control the volume of admission of steam to regulate the mass flow rate without varying the admission pressure. This enables the expander to operate at a constant pressure ratio in the entire turndown compared to throttle governing which is widely used to control the mass flow rate. At 50% load, the expander with dynamic control could generate four times the power than the throttle-governed expanders.