Tank (IL)
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A tanker in an isothermal liquid network.
Description
Block Tank (IL) simulates a vessel with six input ports, A to F, in an isothermal liquid network. The block outputs liquid volume to port V and liquid level to port L as scalar signals. The block models the hydrostatic pressure drop between the liquid surface and the height of the inlet port location. The tank may be at a specified constant pressure, pressure set via an external user signal, or atmospheric pressure.
Fluid volume
The volume of liquid in the tank is determined from the total mass flow in the tank:
where
-
- is the total mass of liquid in the tank entering through all ports;
-
- is the density of the liquid.
Due to the constant pressure in the tank, the volume of liquid inside the tank varies with mass flow rate. Note that the reverse is true for pipes, where pressure is a function of a fixed volume of liquid.
It is possible to set a notification if the volume of liquid in the tank exceeds its capacity. Set the parameters. Liquid volume above max capacity to Warning
if you want to receive a warning when this happens during the simulation, or to Error
if you want the simulation to stop when this happens.
Fluid level
If the parameters Tank volume parameterization is set to Constant cross-sectional area
, the liquid level in the tank is determined by the volume of liquid , which is due to the constant cross-sectional area of the tank opening. Otherwise, the liquid level can be set as tabulated data in the Tabulated data - volume vs. level
option.
If the liquid level in the tank falls below the tank inlet height, the assumption that the liquid completely fills the volume of the connected blocks may not be correct. Connections to the block Pipe (IL), which are based on this assumption, may give unphysical results in this case.
As with the parameters. Liquid volume above max capacity*you can be notified if the liquid level in the tank falls below the height of the inlet(s) during the simulation by setting the parameters to the appropriate value. *Liquid level below inlet height.
Mass flow rate
If you set the Number of inlets parameters to a number greater than 1
, the equations below apply to each port. The dynamic pressure for the inlet port is equal to
where
-
- fluid density;
-
- flow velocity;
-
- mass flow rate of liquid flowing into the tank through the port.
Total pressure
where
-
- is the pressure in the tank:
-
if the parameters Pressurization specification is set to `Atmospheric pressure', then is equal to atmospheric pressure;
-
if the parameters Pressurization specification is set to
Constant specified pressure
, then is equal to the value of the parameters Tank pressurization; -
if the parameters Pressurization specification is set to
Variable pressure
, then is equal to the input signal of the P port.
-
-
- hydrostatic pressure drop at the specified port Inlet height:
,
where is either the height difference between the liquid level and the tank inlet height or zero, whichever is greater.
Assumptions and limitations
If the parameters Pressurization specification is set to Variable pressure
, the block assumes that the pressure change is slow and there is no pressure derivative in the conservation of mass and energy equations.
Ports
Conserving
#
A
—
isothermal liquid port
isothermal liquid
Details
Entering the tank.
Program usage name |
|
#
B
—
isothermal liquid port
isothermal liquid
Details
Additional tank inlet.
Dependencies
To use this parameter, set parameter Number of inlets one of the values: 2
, 3
, 4
, 5
or 6
.
Program usage name |
|
#
C
—
isothermal liquid port
isothermal liquid
Details
Additional tank inlet.
Dependencies
To use this parameter, set parameter Number of inlets one of the values: 3
, 4
, 5
or 6
.
Program usage name |
|
#
D
—
isothermal liquid port
isothermal liquid
Details
Additional tank inlet.
Dependencies
To use this parameter, set parameter Number of inlets one of the values: 4
, 5
or 6
.
Program usage name |
|
#
E
—
isothermal liquid port
isothermal liquid
Details
Additional tank inlet.
Dependencies
To use this parameter, set the parameters Number of inlets to 5
or 6
.
Program usage name |
|
#
F
—
isothermal liquid port
isothermal liquid
Details
Additional tank inlet.
Dependencies
To use this parameter, set the parameters to Number of inlets value 6
.
Program usage name |
|
Output
#
V
—
liquid volume
scalar
Details
The volume of liquid in a tank in m3, given as a scalar.
Data types |
|
Complex numbers support |
No |
#
L
—
liquid level
scalar
Details
Liquid level in a tank in m, given as a scalar.
Data types |
|
Complex numbers support |
No |
Input
#
P
—
tank pressure
scalar
Details
Tank pressure in Pa, given as a scalar.
Dependencies
To use this parameter, set the parameters to Variable pressure
. Pressurization specification to Variable pressure
.
Data types |
|
Complex numbers support |
No |
Parameters
Parameters
#
Number of inlets —
number of input ports
1
| 2
| 3
| 4
| 5
| 6
Details
The number of input ports. Setting this parameter to 2
or more opens additional input ports.
Values |
|
Default value |
|
Program usage name |
|
Evaluatable |
No |
#
Pressurization specification —
tank pressure setting method
Atmospheric pressure
| Constant specified pressure
| Variable pressure
Details
Method of setting tank pressure.
To set a constant pressure other than atmospheric pressure, set this parameter to Constant specified pressure
and specify the pressure value using the parameters Tank pressurization.
To specify a variable tank pressure, set this parameter to Variable pressure
and supply the tank pressure value as a scalar to the P port.
Values |
|
Default value |
|
Program usage name |
|
Evaluatable |
No |
#
Tank pressurization —
user-defined tank pressure
Pa
| GPa
| MPa
| atm
| bar
| kPa
| ksi
| psi
| uPa
| kbar
Details
User-definable tank pressure.
Dependencies
To use this parameter, set the parameters to Specified pressure
. Pressurization specification to Specified pressure
.
Values |
|
Default value |
|
Program usage name |
|
Evaluatable |
Yes |
#
Tank volume parameterization —
tank area characteristics
Constant cross-section area
| Tabulated data - volume vs. level
Details
Specifies the characteristics of the tank area.
This parameters is used to determine the liquid level in the tank. If you want to model a tank with a variable cross-sectional area over the height of the tank, you can provide data for the tank volume as a function of the liquid level using the Tabulated data - volume vs. level
option.
Values |
|
Default value |
|
Program usage name |
|
Evaluatable |
No |
#
Tank cross-sectional area —
tank cross-sectional area
m^2
| cm^2
| ft^2
| in^2
| km^2
| mi^2
| mm^2
| um^2
| yd^2
Details
The cross-sectional area of the tank in the horizontal plane.
Dependencies
To use this parameter, set the parameters Constant cross-section area
to Tank volume parameterization to `Constant cross-section area'.
Values |
|
Default value |
|
Program usage name |
|
Evaluatable |
Yes |
#
Liquid level vector —
vector of liquid level values in the tank
m
| cm
| ft
| in
| km
| mi
| mm
| um
| yd
Details
Vector of liquid level values in the tank for the tabular parameterization of the variable tank area. The values in this vector correspond to the values in the parameters Liquid volume vector. The elements must be positive and listed in ascending order. The first element must be equal to 0
.
Dependencies
To use this parameter, set the parameters Tabulated data - volume vs. level
to Tank volume parameterization to Tabulated data - volume vs. level
.
Values |
|
Default value |
|
Program usage name |
|
Evaluatable |
Yes |
#
Liquid volume vector —
vector of liquid volume values in the tank
l
| gal
| igal
| m^3
| cm^3
| ft^3
| in^3
| km^3
| mi^3
| mm^3
| um^3
| yd^3
| N*m/Pa
| N*m/bar
| lbf*ft/psi
| ft*lbf/psi
Details
Vector of tank liquid volume values for the tabular parameterization of the tank area variable. The values in this vector correspond to the values in the parameters Liquid level vector. The elements must be positive and listed in ascending order. The first element must be equal to 0
.
Dependencies
To use this parameter, set the parameters Tabulated data - volume vs. level
to Tank volume parameterization to Tabulated data - volume vs. level
.
Values |
|
Default value |
|
Program usage name |
|
Evaluatable |
Yes |
#
Inlet height —
tank inlet height
m
| cm
| ft
| in
| km
| mi
| mm
| um
| yd
Details
The height of the tanker inlet. The value must be greater than or equal to 0
.
Dependencies
To use this parameter, set the parameter Number of inlets value 1
.
Values |
|
Default value |
|
Program usage name |
|
Evaluatable |
Yes |
#
Inlet cross-sectional area —
cross-sectional area of the tank inlet
m^2
| cm^2
| ft^2
| in^2
| km^2
| mi^2
| mm^2
| um^2
| yd^2
Details
The cross-sectional area of the tank inlet port. This value must be greater than 0
.
Dependencies
To use this parameter, set the parameters to 1
. Number of inlets value 1
.
Values |
|
Default value |
|
Program usage name |
|
Evaluatable |
Yes |
#
Height vector for inlets A and B —
vector of height of ports A and B
m
| cm
| ft
| in
| km
| mi
| mm
| um
| yd
Details
Port height vector for enabled input ports A and B. Parameters Height vector for inlets A and B is a vector of values corresponding to the height of each input port starting from port A. Each element of this vector must be greater than or equal to 0
.
Dependencies
To use this parameter, set the parameters to Number of inlets one of the values: 2
.
Values |
|
Default value |
|
Program usage name |
|
Evaluatable |
Yes |
#
Cross-sectional area vector for inlets A and B —
vector of cross-sectional areas of input ports A and B
m^2
| cm^2
| ft^2
| in^2
| km^2
| mi^2
| mm^2
| um^2
| yd^2
Details
Vector of cross-sectional areas of tank inlets for included inlet ports A and B. Parameters Cross-sectional area vector for inlets A and B is a vector of values corresponding to the cross-sectional area of each inlet port, starting from port A. Each element of this vector must be greater than 0
.
Dependencies
To use this parameter, set the parameters to Number of inlets one of the values: 2
.
Values |
|
Default value |
|
Program usage name |
|
Evaluatable |
Yes |
#
Height vector for inlets A, B, and C —
vector of height of ports A, B and C
m
| cm
| ft
| in
| km
| mi
| mm
| um
| yd
Details
Port height vector for enabled input ports A, B and C. Parameters Height vector for inlets A, B, and C is a vector of values corresponding to the height of each input port, starting from port A. Each element of this vector must be greater than or equal to 0
.
Dependencies
To use this parameter, set the parameters to Number of inlets one of the values: 3
.
Values |
|
Default value |
|
Program usage name |
|
Evaluatable |
Yes |
#
Cross-sectional area vector for inlets A, B, and C —
vector of cross-sectional areas of input ports A, B and C
m^2
| cm^2
| ft^2
| in^2
| km^2
| mi^2
| mm^2
| um^2
| yd^2
Details
Vector of cross-sectional areas of tank inlets for included inlet ports A, B and C. Parameters Cross-sectional area vector for inlets A, B, and C is a vector of values corresponding to the cross-sectional area of each inlet port, starting from port A. Each element of this vector must be greater than 0
.
Dependencies
To use this parameter, set the parameters to Number of inlets one of the values: 3
.
Values |
|
Default value |
|
Program usage name |
|
Evaluatable |
Yes |
#
Height vector for inlets A, B, C and D —
vector of height of ports A, B, C and D
m
| cm
| ft
| in
| km
| mi
| mm
| um
| yd
Details
Port height vector for enabled input ports A, B, C and D. Parameters Height vector for inlets A, B, C and D is a vector of values corresponding to the height of each input port, starting from port A. Each element of this vector must be greater than or equal to 0
.
Dependencies
To use this parameter, set the parameters to Number of inlets one of the values: 4
.
Values |
|
Default value |
|
Program usage name |
|
Evaluatable |
Yes |
#
Cross-sectional area vector for inlets A, B, C and D —
vector of cross-sectional areas of the input ports A, B, C and D
m^2
| cm^2
| ft^2
| in^2
| km^2
| mi^2
| mm^2
| um^2
| yd^2
Details
Vector of cross-sectional areas of tank inlets for included inlet ports A, B, C and D. Parameters Cross-sectional area vector for inlets A, B, C and D is a vector of values corresponding to the cross-sectional area of each inlet port, starting from port A. Each element of this vector must be greater than 0
.
Dependencies
To use this parameter, set the parameters to Number of inlets one of the values: 4
.
Values |
|
Default value |
|
Program usage name |
|
Evaluatable |
Yes |
#
Height vector for inlets A, B, C, D and E —
vector of height of ports A, B, C, D and E
m
| cm
| ft
| in
| km
| mi
| mm
| um
| yd
Details
Port height vector for enabled input ports A, B, C, D and E. Parameters Height vector for inlets A, B, C, D and E is a vector of values corresponding to the height of each input port, starting from port A. Each element of this vector must be greater than or equal to 0
.
Dependencies
To use this parameter, set parameter Number of inlets value 5
.
Values |
|
Default value |
|
Program usage name |
|
Evaluatable |
Yes |
#
Cross-sectional area vector for inlets A, B, C, D and E —
vector of cross-sectional areas of input ports A, B, C, D and E
m^2
| cm^2
| ft^2
| in^2
| km^2
| mi^2
| mm^2
| um^2
| yd^2
Details
Vector of cross-sectional areas of tank inlets for included inlet ports A, B, C, D and E. Parameters Cross-sectional area vector for inlets A, B, C, D and E is a vector of values corresponding to the cross-sectional area of each inlet port, starting from port A. Each element of this vector must be greater than 0
.
Dependencies
To use this parameter, set the parameters for parameter Number of inlets value 5
.
Values |
|
Default value |
|
Program usage name |
|
Evaluatable |
Yes |
#
Height vector for inlets A, B, C, D, E and F —
vector of height of ports A, B, C, D, E and F
m
| cm
| ft
| in
| km
| mi
| mm
| um
| yd
Details
Port height vector for enabled input ports A, B, C, D, E and F. Parameters Height vector for inlets A, B, C, D, E and F is a vector of values corresponding to the height of each input port, starting with port A. Each element of this vector must be greater than or equal to 0
.
Dependencies
To use this parameter, set parameter Number of inlets value 6
.
Values |
|
Default value |
|
Program usage name |
|
Evaluatable |
Yes |
#
Cross-sectional area vector for inlets A, B, C, D, E and F —
vector of cross-sectional areas of input ports A, B, C, D, E and F
m^2
| cm^2
| ft^2
| in^2
| km^2
| mi^2
| mm^2
| um^2
| yd^2
Details
Vector of cross-sectional areas of tank inlets for included inlet ports A, B, C, D, E and F. The parameters Cross-sectional area vector for inlets A, B, C, D, E and F is a vector of values corresponding to the cross-sectional area of each inlet port, starting from port A. Each element of this vector must be greater than 0
.
Dependencies
To use this parameter, set the parameters to. Number of inlets value 6
.
Values |
|
Default value |
|
Program usage name |
|
Evaluatable |
Yes |
#
Liquid level below inlet height —
notification of low liquid level in the tank
None
| Warning
| Error
Details
Whether to receive a notification if the liquid level in the tanker drops below the port inlet height during the simulation. Set this parameters to Warning
if you want to receive a warning when this happens during simulation. Set Error
if you want the simulation to stop when this happens.
Values |
|
Default value |
|
Program usage name |
|
Evaluatable |
No |
#
Liquid volume above max capacity —
notification of excess tank volume
None
| Warning
| Error
Details
Whether to be notified if the volume of liquid in the tank exceeds the maximum tank capacity during the simulation. Set this parameters to Warning
if you want to receive a warning when this happens during simulation. Set Error
if you want the simulation to stop when this happens.
Values |
|
Default value |
|
Program usage name |
|
Evaluatable |
No |
#
Maximum tank capacity —
tank filling limit
l
| gal
| igal
| m^3
| cm^3
| ft^3
| in^3
| km^3
| mi^3
| mm^3
| um^3
| yd^3
| N*m/Pa
| N*m/bar
| lbf*ft/psi
| ft*lbf/psi
Details
Tank filling limit.
Dependencies
To use this parameter, set the parameters Warning
or Error
. Liquid volume above max capacity to Warning
or Error
.
Values |
|
Default value |
|
Program usage name |
|
Evaluatable |
Yes |
#
Gravitational acceleration —
free-fall acceleration
gee
| m/s^2
| cm/s^2
| ft/s^2
| in/s^2
| km/s^2
| mi/s^2
| mm/s^2
Details
Free-fall acceleration.
Values |
|
Default value |
|
Program usage name |
|
Evaluatable |
Yes |