Structural model of ship refrigeration unit
Based on the analysis of the processes occurring in the refrigerating chamber and evaporator of the ship's refrigeration plant, as well as the equations of heat balance, a mathematical description of the dynamics of the boiling point and the cooled object is obtained. Analysis of the processes in the ship's refrigeration plant is carried out for two-position control of the compressor cooling capacity. A block diagram of a simulation model of a ship's refrigeration plant, as an automation object is proposed. The main difference of the developed model is taking into account changes in time constants and transmission coefficients in the cooling and warming modes of the ship's refrigeration plant chambers. The simulation model of the ship's refrigeration plant being implemented in the Matlab / Simulink simulation environment, allows estimating the change in the boiling point and the cooled object taking into account the change in the ambient temperature and the settings of the two-position controller. As an example, at different ambient temperatures, a study of the dynamic properties of the ship's refrigeration plant with a cooling capacity of 14О kW in a refrigerator vessel designed for transporting citrus fruits, was performed. The analysis of the resulting transient processes in the evaporator and the refrigeration chamber of the ship's refrigeration plant was carried out, and ways of improving the model of the ship's refrigeration plant were outlined.