Review of prior research and new technology for horizontal-tube falling-film evaporator used in refrigeration

A review of the prior research on horizontal-tube falling-film evaporator used in refrigeration is presented. The review mainly includes falling film flow and heat transfer mechanism, such as intertube flow modes, falling film characters, film thickness over the horizontal tubes, flowing refrigerant gas, heat transfer and so on. Except for, the technology for flow uniformity and stability and methods of avoiding dryout had been summarized. On the base of prior study, a new technology to improve flow uniformity and stability and avoid dryout had been introduced, which includes the flow-leading and second liquid-distributing. The flowing-leading technology could give a steady liquid flowing without gas interference by fixing different enlarged fins on the under-side of the horizontal tube, and the second liquid-distributing technology could ensure the liquid distributing uniformly without dryout by collecting and distributing the liquid along the gas channel. The new technology has been proved to ensure liquid flowing steadily and distributing uniformly along the horizontal tubes without dryout efficiently.