Dimensionless analysis of heat transfer and flow resistance on laminar flow recuperator

Recuperator is one of the key components in the helium-turbine cycle coupled with High Temperature Gas cooled Reactor (HTGR). Synthetically considering the heat transfer coefficients, the pressure drop and installation space of recuperator, it is obviously a trend to use compact heat exchanger as recuperator in nuclear power plant. Recuperator recovers heat from the turbine exhaust gas. It promotes the cycle efficiency over entire power range and in all typical modes including start up and shut down modes. The recuperator's heat transfer coefficients, height, pressure drop have effect on the recuperator's effectiveness. The main purpose of this paper is to present the law of heat transfer and flow resistance in laminar flow compact exchanger. Based on the similarity theory, the dimensionless parameters of the plate-fin heat exchanger is given in this paper; and then the the dimensionless analysis of the over-all heat transfer coefficient, recuperator's effectiveness and flow resistance is presented. Furthermore, relationship between the pressure drop and length is also developed.