building-energy-model-matlab：这是由MATLAB开发的用于对建筑物或HVAC系统的能源系统进行建模的...

# Building Energy Model (MATLAB) # It is a small software which is developed by MATLAB for modeling the energy system of a building or a HVAC system. ## Method of Solution ## In this code, the temperatures are considered variables of the problem, which are solved implicitly by solving a system of linear equations based on energy equations of each element. ## Elements Classes ## ### Boiler ### The boiler contains an inlet fluid pipe, an outlet fluid pipe, a fluid tank which is heated up, and the rest. The class of boiler receives input values including the id of the inlet, the id of outlet, the solver, the specific heat capacity of the rest, the mass of the rest, specific heat capacity of the fluid, mass of the fluid, the boiler power, the mass flow rate, and the status. The inlet and outlet should be outlet and inlet of pipes which are connected to the boiler respectively. The solver is the class of the solver that is used. Next, there are specific heat capacity and mass of the boiler except containing fluid. Then, there are those of the fluid. The next argument is the power of the boiler. The mass flow rate also should be given as an input value. The status works as a switch in the boiler which can be controlled by the smart controller in the next stages of the project. #### Equations ####   #### Variables #### | Symbol | Description | Unit | | --- | --- | --- | | *m* | Mass | *kg* | | *C* | Specific Heat Capacity | *J/(K.kg)* | | *T* | Temperature | *K* | | *E.* | Energy Rate | *W* | | Subscript | Description | | --- | --- | | *b* | Boiler | | *f* | fluid | | *b,f* | Fluid inside Boiler | | *b,i* | Boiler Inlet | | *b,o* | Boiler Outlet | #### Code #### ##### Construction ###### ```Matlab boiler = Boiler(id_inlet, id_outlet, solver, specific_heat_capacity, mass, specific_heat_capacity_fluid, mass_fluid, power, mass_flow_rate, status); ``` | Input | Description | Type | Unit | | --- | --- | --- | --- | | `id_inlet` | Boiler Inlet ID | `integer` | - | | `id_outlet` | Boiler Outlet ID | `integer` | - | | `solver` | Class of the Solver | `solver` | - | | `specific_heat_capacity` | Specific Heat Capacity of the Boiler (without fluid) | `double` | *J/(K.kg)* | | `mass` | Mass of the Boiler (without fluid) | `double` | *kg* | | `specific_heat_capacity_fluid` | Specific Heat Capacity of the Fluid | `double` | *J/(K.kg)* | | `mass_fluid` | Mass of Fluid inside the Boiler | `double` | *kg* | | `power` | Power of the Boiler | `double` | *W* | | `mass_flow_rate` | Mass Flow Rate of the Boiler | `double` | *kg/s* | | `status` | Status of the Boiler (ON/OFF) | `boolean` | - | ##### Create Matrix ##### ```Matlab create(solver) ``` | Input | Description | Type | Unit | | --- | --- | --- | --- | | `solver` | Class of the Solver | `solver` | - | --- ### Pipe ### Another element in the model is the pipe. The input values of the pipe class are the id of inlet, the id of outlet, the id of zone, the solver, specific heat capacity of the pipe wall, density of the pipe wall, specific heat capacity of the fluid, density of the fluid, mass flow rate of the fluid, inner heat transfer coefficient, outer heat transfer coefficient, thermal conductivity of the tube wall, inner radius of the pipe, outer radius of the pipe, and length of the pipe. The inlet and outlet of the pipe are the elements which are connected to the pipe. The zone which is in contact with the outer side of the pipe is also the argument of the class. #### Equations ####   #### Variables #### | Symbol | Description | Unit | | --- | --- | --- | | *h* | Heat Transfer Coefficient | *W/(m²K)* | | *r* | Radius | *m* | | *D* | Diameter | *m* | | *k* | Thermal Conductivity | *W.m^-1.K^-1* | | *L* | Length | *m* | | *U* | equivalent heat transfer coefficient | *W/(m²K)* | | *Nu* | Nusselt Number | - | | *Re* | Reynolds Number | - | | *Pr* | Prandtl Number | - | | *Ra* | Rayleigh Number | - | | *g* | Gravitational Acceleration | m/s² | | *&‌beta;* | Coefficient of Volume Expansion | 1/K | | *&‌nu;* | Kinematic Viscosity | m²/s | | *&‌mu;* | Dynamic Viscosity | kg·m⁻¹·s⁻¹ | | Subscript | Description | | --- | --- | | *t* | Pipe | | *t,f* | Fluid inside Pipe | | *t,i* | Pipe Inlet | | *t,o* | Pipe Outlet | | *t,in* | Pipe Inner Side | | *t,out* | Pipe Outer Side | #### Code #### ##### Construction ###### ```Matlab pipe = Pipe(id_inlet, id_outlet, id_zone, solver, specific_heat_capacity, density, specific_heat_capacity_fluid, density_fluid, mass_flow_rate,thermal_conductivity,thermal_conductivity_fluid,radius_inner,radius_outer,length,dynamic_viscosity_fluid,dynamic_viscosity_air,density_air,specific_heat_capacity_air,thermal_conductivity_air); ``` | Input | Description | Type | Unit | | --- | --- | --- | --- | | `id_inlet` | Pipe Inlet ID | `integer` | - | | `id_outlet` | Pipe Outlet ID | `integer` | - | | `id_zone` | Zone ID | `integer` | - | | `solver` | Class of the Solver | `solver` | - | | `specific_heat_capacity` | Specific Heat Capacity of the Pipe (without fluid) | `double` | *J/(K.kg)* | | `density` | Density of the Pipe (without fluid) | `double` | *kg/m³* | | `specific_heat_capacity_fluid` | Specific Heat Capacity of the Fluid | `double` | *J/(K.kg)* | | `density_fluid` | Density of Fluid inside the Pipe | `double` | *kg/m³* | | `mass_flow_rate` | Mass Flow Rate of the Pipe | `double` | *kg/s* | | `thermal_conductivity` | Thermal Conductivity of the Pipe | `double` | *W.m^-1.K^-1* | | `thermal_conductivity_fluid` | Thermal Conductivity of the Fluid | `double` | *W.m^-1.K^-1* | | `radius_inner` | Inner Radius of the Pipe | `double` | *m* | | `radius_outer` | Outer Radius of the Pipe | `double` | *m* | | `length` | Length of the Pipe | `double` | *m* | | `dynamic_viscosity_fluid` | Dynamic Viscosity of the Fluid | `double` | *N·s/m²* | | `dynamic_viscosity_air` | Dynamic Viscosity of the Air | `double` | *N·s/m²* | | `density_air` | Density of the Air | `double` | *kg/m³* | | `specific_heat_capacity_air` | Specific Heat Capacity of the Air | `double` | *J/(K.kg)* | | `thermal_conductivity_air` | Thermal Conductivity of the Air | `double` | *W.m^-1.K^-1* | ##### Create Matrix ##### ```Matlab create(solver) ``` | Input | Description | Type | Unit | | --- | --- | --- | --- | | `solver` | Class of the Solver | `solver` | - | --- ### Radiator ### The input values of the radiator class are the id of inlet, the id of outlet, the id of zone, the solver, specific heat capacity of the radiator except containing fluid, mass of the radiator except containing fluid, specific heat capacity of the fluid, mass of fluid, mass flow rate of the fluid, heat transfer coefficient of the radiator to the zone, the surface of the radiator which is in contact to the air of the zone. #### Equations ####   #### Variables #### | Subscript | Description | | --- | --- | | *r* | Radiator | | *r,f* | Fluid inside Radiator | | *r,i* | Radiator Inlet | | *r,o* | Radiator Outlet | | *z* | Zone | #### Code #### ##### Construction ###### ```Matlab radiator = Radiator(id_inlet, id_outlet, id_zone, solver, specific_heat_capacity, mass, specific_heat_capacity_fluid, mass_fluid, mass_flow_rate,heat_transfer_coefficient,surface); ``` | Input | Description | Type | Unit | | --- | --- | --- | --- | | `id_inlet` | Radiator Inlet ID | `integer` | - | | `id_outlet` | Radiator Outlet ID | `integer` | - | | `id_zone` | Zone ID | `integer` | - | | `solver` | Class of the Solver | `solver` | - | | `specific_heat_capacity` | Specific Heat Capacity of the Radiator (without fluid) | `double` | *J/(K.kg)* | | `mas