Automatic Unit Number Binding with Refrigeration Circuit Identification for Air-Conditioner Control Network

Abstract

This paper proposes an automatic unit number binding method so that a number of logical subsystems are defined in the whole control network for distributed air-conditioners. Each air-conditioner unit starts the proposed algorithm at random timing to allocate its own unit number without any server. Then each outside unit one by one broadcasts the check signal and flows refrigerant gas to the refrigerant circuit between units to make each inside unit discover its piping connection. As a result, a number of logical subsystems are defined in the whole control network. A Petri net model was constructed for verification of our proposed system. For the case of two outside units and three inside units, the reachability to the required states and the deadlock free property were verified. The generalized module-by-module Petri net construction procedure shows applicability to general cases of arbitrary number of units.