| A comprehensive computer-aided methodology for the design and rating of heat exchangers has been developed. Central roles are played in the design methodology by the concept of availability (exergy) and a heat exchanger total cost function. The total cost function expresses on an annualized basis the sum of the capital cost and the fuel cost attributable to heat exchanger nonideality.; The methodology explicitly uses the second law of thermodynamics concept of irreversibility, which accounts for the destruction of availability owing to fluid friction and heat transfer through the stream-to-stream temperature difference, together with cost data, and customary heat exchanger parameters (heat transfer area, effectiveness, number of transfer units, pressure drop, and geometry) to achieve thermodynamically efficient and cost-effective designs. The term thermoeconomics has been coined to describe the use of principles drawn from the thermosciences and engineering economics for the purpose of rational decision making in the development of thermal systems. This study represents the most complete application thus far of the principles of thermoeconomics to the field of heat exchanger design.; The methodology developed has been applied to the design of the following types of heat exchangers: (1) Compact (plate-fin). (2) Periodic-flow matrix. (3) Tube-within-a-tube. The heat exchanger configurations may be gas-to-gas, gas-to-liquid, or liquid-to-liquid. The fluids can be arranged in crossflow, counterflow, or parallel-flow depending upon the type of heat exchanger. Relations between the effectiveness, pressure drop, heat transfer area, and irreversibility have been developed and represented both analytically and in graphical form. Comparisons have been made between designs obtained with the methodology of this dissertation and actual production heat exchanger designs. Heat exchangers other than those specifically mentioned also can be studied with the methodology of this dissertation. |
