Review on Double Pipe Heat Exchanger with Inserts: Performance, Application, and Future Scope

Double pipe heat exchangers (DPHEs) are widely employed for low-to medium-capacity thermal applications due to their simple design and flexibility.Passive heat transfer enhancement using inserts such as twisted tapes, wire coils, helical, and perforated types has been extensively investigated to improve thermal performance.This review paper discusses the fundamentals of DPHEs, types of inserts, experimental and numerical studies, thermal-hydraulic performance, applications, advantages, limitations, and future research scope.The review consolidates recent findings, highlights key trends, and identifies potential areas for further investigation in the field of insert-enhanced DPHEs.