PIPES WITH GROOVES FOR REVERSIBLE USAGE AT HEAT EXCHANGERS Russian patent published in 2006 - IPC F28F1/40 

FIELD: heat exchangers.

SUBSTANCE: metal pipes with grooves, which pipes have thickness of T_f at bottom part of groove and external diameter of D_e, are intended for manufacture of heat exchangers. The heat exchanger operates either in evaporation or condensation modes or reversible mode. They use liquid cooling agent with phase change. Grooves are provided inside pipes and they are formed by means of N spiral-shaped ribs with α angle at vertexes of ribs. Ribs have height H, width of basis L_n and angle β of spiral. Two neighboring ribs are separated from each other by groove with flat bottom of L_R width. The ribs are disposed with pitch P, which equals to L_R+L_N. External diameter D_e of pipe equals to 4-20 mm. Number of ribs can change within 46 to 98 pieces. In particular, the number of ribs increases when external diameter D_e of pipe increases. Height of ribs varies from 0.18 to 0.40 mm and it can change depending on external diameter D_e of pipe. Angle of α at vertexes of ribs has value which meets the relation of 15°≤α≤30°. Angle β of spiral varies within 18° to 35° range. For the pipe described, Cavallini factor equals to at least 3,1. Heat exchangers are also offered, in which heat exchangers the described pipes are used. Method of application of those pipes and heat exchangers is described for reversible air conditioners and in cooler-type multiple-pipe heat exchangers.

EFFECT: improved efficiency of operation; reduced cost' better characteristics of heat exchange as in evaporation and in condensation modes.

28 dwg