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Thermal Management
Custom MIT shell and tube heat exchanger for ORC system heat recovery
3D model of the shell and tube heat exchanger .
Following a customer ’ s request , the Ekin Endustriyel Team was tasked with providing a specific heat exchanger design that would be suitable for flue gas within an electrical machinery facility . This case study highlights how the team successfully met the heat requirements of a 132 kW capacity
ORC system by implementing an innovative energy recovery solution using a shell and tube heat exchanger .
About the author
Enes Kuzey Er is the Heat Transfer Product Sales - R & D Specialist for Ekin Endustriyel , responsible for sales of heat transfer products such as plate type heat exchangers ( gasketed or brazed ) and shell and tube heat exchangers . He is also researching solutions for industry needs through customer feedback , and provides support for related research and development processes .
By Enes Kuzey Er - R & D Specialist , Ekin Endustriyel
Initial task The customer generates power through the Organic Rankine Cycle ( ORC ) and converts it into electricity with turbines . Thermal oil , at a temperature of 160 ° C , serves as the secondary fluid in the ORC process . Due to heat transfer in the process , the thermal oil loses enthalpy , resulting in a temperature decrease to 125 ° C . At this stage , an external heat source is required , leading to the implementation of a shell and tube heat exchanger , chosen for its compatibility with high temperatures and process fluids .
The solution Within another section of the facility , there is a steam production line utilizing natural gas . After processing , the natural gas becomes waste flue gas at 260 ° C . This waste flue gas serves as the external heat source , enabling thermal energy recovery for heating the thermal oil in the ORC process . The flue gas enters the heat exchanger at 260 ° C and exits at 155 ° C after cooling . Meanwhile , the thermal oil enters at 125 ° C and exits at 160 ° C after heating . The shell and tube heat exchanger facilitates a total work of 950 kW .
Custom heat exchanger The heat exchanger is designed according to TEMA standards as the NEN type . It features a shell diameter of 1300 mm and a total length of approximately 5500 mm . Flue gas flows through the inner tubes while thermal oil circulates within the shell . To withstand the potentially corrosive nature of the waste natural gas , all components in contact with the inner fluid are manufactured from stainless steel , while other parts of the heat exchanger are made from carbon steel . The material standards adhere to EN-10025 for the shell and EN-10216 for the inner tubes , ensuring both economic efficiency and reliability .
Results Following heat recovery with the shell and tube heat exchanger , the heated thermal oil is sent to the ORC section , maintaining a closed continuous cycle within a combined structure . Through the utilization of this 950 kW heat recovery system , the thermal requirement of 132 kW for the ORC system is fully met .
NEN type heat exchanger .
52 Heat Exchanger World June 2024 www . heat-exchanger-world . com