Heat Transfer Effectiveness of Three-Fluid Separated Heat Pipe Exchanger

A heat transfer model for three-fluid separated heat pipe exchanger was analyzed,and the temperature transfer matrix for general three-fluid separated heat exchanger working in parallel-flow or counter-flow mode was obtained.It was found that the forms of temperature transfer matrix are similar for heat pipe rows with equal or different heat transfer surface area.Furthermore,by using the temperature transfer matrix of the heat pipe exchanger,the relationship between heat transfer effectiveness θ 1,θ 2 and M,NTU,U,Δt i were derived for the exchanger operating in parallel-flow or counter-flow mode,and a simple special example was adopted to demonstrate the correctness of these relationships.