Static/dynamic analyses for pumped two-phase fluid loop control

Abstract

Theoretical/computational analyses are made for active temperature control of mechanically-pumped two-phase fluid loops. The loops, taken as analysis objects, are of vapor/liquid mixed type (MTPFL) or of vapor/liquid separated type (STPFL). Simultaneous nonlinear equations governing heat acquisition/ transport/rejection are introduced to state a thermal balance in a MTPFL and in a STPFL. Also introduced is an additional relation defining a pressure balance in a STPFL. Multiplicative expressions are then given to calculate hydraulic pressure losses in the two. All the equations/relations/expressions are integrated to yield a comprehensive model of MTPFL and of STPFL, from which derived are simplified algorithms for solving off-design operations problems. Solution methods, applicable to three cases of operational interest, are mathematically described in the tables. Predicted off-design performances and required control parameter values are graphically shown in the figures as demonstrative examples of the solutions. Another kind of analysis is then made at subsystem level for more precise temperature control. The subsystems of concern are an evaporative cold plate of vapor/liquid mixed type (MECP), that of vapor/liquid separated type (SECP), and