Recent advances in design and performance optimization of pillow-plate heat exchangers: a critical review

Over the last two decades, extensive research has been dedicated to the crisis stemming from fossil fuel usage and its environmental repercussions. This pressing concern has garnered substantial attention due to its potential to disrupt ecological equilibrium and sustainability. Pursuing more efficient and sustainable solutions in the heat exchangers realm has catalyzed the development and optimization of innovative designs, notably pillow-plate heat exchangers (PPHEs). These next-generation heat exchangers offer improved compactness and reduced material requirements, effectively tackling mounting concerns related to energy and resource consumption. Integrating such advancements can mitigate the adverse environmental impact, fostering a greener and more sustainable future. This paper presents an exhaustive review of recent progress in PPHE design and optimization, emphasizing their potential for widespread application across diverse industries. These innovative heat exchangers feature sleek, pillow-like channels, offering exceptional heat transfer capabilities and minimal pressure drops. These attributes position PPHEs as a compelling and eco-conscious alternative to traditional heat exchangers. Nevertheless, the intricate geometries of PPHEs pose challenges for comprehensive research, and existing studies underscore the limited number and scope of their industrial applications. This manuscript thoroughly examines the critical facets of the literature related to various aspects of PPHEs, encompassing manufacturing processes, thermohydraulic channel characteristics, design algorithms, and cost assessments. By meticulously identifying and emphasizing critical research gaps, this work not only underscores the need for further investigation but also sets the stage for future studies to enhance the reliability and performance of PPHEs as a heat transfer equipment solution.