There is a pre-load function included in the model properties. This runs when the model is opened. The simplest solution is to close the model and reopen it. Otherwise, navigate to Model Properties and copy the pre-load function code to a script and run it there.
load r134aPropertyTables
% Refrigerant:
initial_pressure = 0.6; % MPa
initial_quality = 0.05;
% Environment:
environment_temperature = 293; % K
natural_convection_coefficient = 20; % W/m^2/K
% Controller:
target_temperature = 277; % K
temperature_delta = 2; % K
% Compressor:
commanded_mass_flow = 0.004; % kg/s
controller_time_constant = 20; % s
% Expansion valve:
min_throat_area = 0.1; % mm^2
max_throat_area = 1.5; % mm^2
min_throat_temperature = 270; % K
max_throat_temperature = 250; % K
% Heat exchangers:
condenser_length = 30; % m
evaporator_length = 30; % m
fin_area = 1; % m^2
fin_convection_coefficient = 150; % W/m^2/K
% Pipes:
pipe_diameter = 0.01; % m
pipe_thickness = 0.0005; % m
% Refrigerator compartment:
interior_surface_area = 4.5; % m^2
exterior_surface_area = 6; % m^2
foam_thickness = 0.03; % m
% Material properties:
copper_density = 8940; % kg/m^3
copper_specific_heat = 390; % J/kg/K
copper_conductivity = 400; % W/m/K
foam_conductivity = 0.03; % W/m/K
You can learn more about model callbacks here: https://www.mathworks.com/help/simulink/ug/model-callbacks.html
