Constructal Design of Refrigeration Devices

The objective of refrigeration is to achieve and maintain a temperature below that of the surroundings. The refrigeration industry is expanding worldwide to fulfill the increasing needs to ensure living conditioning of humans. For example, in China, 10,272 million domestic refrigerators and freezers were manufactured in 2009 [1]. The adverse aspect is that refrigeration devices consume a large amount of energy in the world, which invokes more efficient and economical design. The design of refrigeration devices involves many aspects, in which fluid flow is a key mechanism. Due to the complexity of flow process in refrigeration applications, to a large extent, trial-and-error method has been the mainstream technique for a long time. Since Bejan proposed the constructal law in 1996 [2], principle-based flow system optimization technique has been practiced by many engineers in diverse fields [3, 4]. Like in other flow engineering fields, constructal theory is playing a more and more important role in improving the design of refrigeration devices [3–12]. In this chapter, we present our recent advances in constructal optimization in refrigeration devices through two case studies, i.e., domestic freezers and heat pump water heaters.