A generalized algorithm called ALG-I as well as a companion algorithm called ALG-II

for simulation of variable refrigerant flow (VRF) systems were proposed. Firstly

the principles and methods to find the criteria of iterative calculation and choose the variables of iterative calculation were introduced. Then

the standard algorithm was organized by some proper combination between the iterative variables and the iterative criteria

and the critical steps of the algorithm were described in detail. ALG-I and ALG-II have very similar characteristics except time-consuming. Simulation results revealed that the models established are feasible and effective to simulate the VRF systems with different number of evaporators

which indicates the proposed system algorithms are generic and evaporator-number independent. For the VRF system with only one evaporator

the much larger time consuming of the ALG-I weakened the potential for control analysis applications

while for the multi-evaporator VRF system

the ALG-I has advantages over the ALG-II. Finally

tests also showed the proposed algorithms good ability responding to varying control variables including the openness of the throttling valves and speed of the compressor. It is concluded that the system model is feasible to be applied and lays solid foundation for the studies including performance and control analysis of the VRF systems.