Material Body
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Navigation: Models ➔ Material Handling Models ➔ Material Body
Related Links: Material
Available from Build 139.
General Description
The main purpose of this unit operation is to simulate the transfer of heat through a body of material. Examples of this are linings of kilns or smelters, and insulation of vessels and pipes.
The model calculates unsteady heat conduction in one dimension. The body can contain multiple materials with different thicknesses.
Heat transfer via convection at the two edges (inner and outer) of the material to the external environment is also calculated.
The model can be a standalone unit with no Pipe connections, or it can be connected to incoming and outgoing streams and heat can be exchanged between the material and the stream.
The model uses the Material sub-model for the bulk of the calculations.
Inputs and Outputs
| Label | Input / Output | No. of Connections | Description | |
|---|---|---|---|---|
| Min | Max | |||
| Feed | In | 0 | 10 | General purpose inlet. |
| Product | Out | 0 | 1 | General purpose outlet. |
The model can have no connections, and simply perform stand alone calculations. If at least one feed stream is connected then the product stream must be connected and vice-versa.
Model Theory
Please refer to the Material sub-model for an explanation of basic theory including:
The fundamental heat transfer equations are solved by finite difference approximation. There are several methods for the user to choose from. These are explained in more detail in the following links:
- Rectangular Crank-Nicolson Scheme
- Rectangular Crank-Nicolson Non-Linear Scheme
- Rectangular Douglas-Gunn Scheme
- Cylindrical Crank-Nicolson Scheme
- Cylindrical Crank-Nicolson Non-Linear Scheme
There are 5 options for the determination of the temperatures at the faces of the wall. This is affected by:
- If streams are connected to the Material Body model the stream data will influence the external temperature on one side.
- If the ExternalEffect setting is enabled (only available when no streams are connected), then the external temperature on one side will be calculated based on user specified fluid properties.
- The setting of the ConnectionTo field will determine which external temperature (inside or outside) is determined by calculation instead of user input.
| Configuration | Connected | ExternalEffect | ConnectionTo | Inside Face Temperature | Outside Face Temperature |
|---|---|---|---|---|---|
| 1 | No | Disabled | N/A | Single user input | Single user input |
| 2 | Yes | N/A | Inside Face | Feed stream temperature | Single user input |
| 3 | Yes | N/A | Outside Face | Single user input | Feed stream temperature |
| 4 | No | Enabled | Inside Face | Calculation based on multiple user inputs | Single user input |
| 5 | No | Enabled | Outside Face | Single user input | Calculation based on multiple user inputs |
Data Sections
The default sections and variable names are described in detail in the following tables. The number of sections may increase or decrease, based on user configuration.
- MaterialBody -- This tab page contains general configuration information.
- Layout -- This tab page is the main page used for configuration of the model.
- Layers -- This tab page contains a summary table of key information about each layer.
- LXXX -- Optional tab, only visible if LayerToView is non-zero. The user can select the individual layer to view and the name of this tab will change accordingly, i.e. if the set LayerToView = 1, then the tab will be L001.
- Content -- Optional tab, only visible if ShowTotalContent is enabled. Contains data on the total material in all layers.
- TempProfile -- This tab page contains a summary table of current and previous temperatures in each layer.
- MaterialX -- One page per Material defined on the Layout page. Allows user to define composition of material.
- Info tab - Contains general settings for the unit and allows the user to include documentation about the unit and create Hyperlinks to external documents.
- Links tab, contains a summary table for all the input and output streams.
- Audit tab - Contains summary information required for Mass and Energy balance. See Model Examples for enthalpy calculation Examples.
Unit Type: MaterialBody - The first tab page in the access window will have this name.
Material Body
| Tag (Long/Short) | Input / Calc | Calculated Variables / Options |
|---|---|---|
| Tag | Display | This name tag may be modified with the change tag option. |
| Condition | Display | OK if no errors/warnings, otherwise lists errors/warnings. |
| ConditionCount | Display | The current number of errors/warnings. If condition is OK, returns 0. |
| GeneralDescription / GenDesc | Display | This is an automatically generated description for the unit. If the user has entered text in the 'EqpDesc' field on the Info tab (see below), this will be displayed here. If this field is blank, then SysCAD will display the UnitType or SubClass. |
| Requirements | ||
| On | Tick Box | If this option is deselected, the material body will not be operational and no heat transfer will occur. |
| ExternalEffect | Tick Box | Only available if pipes have NOT been connected to the Material Body model. If this option is selected, the external temperature of one of the walls/edges of the material body will be changed by heat transfer with the material body and additional parameters will appear on the page. |
| ConnectionTo | Only visible if ExternalEffect is enabled or pipes have been connected to the Material Body model. | |
| Inside Face | The fluid that is in contact with the material body is adjacent to the inside face of the wall of the material body. | |
| Outside Face | The fluid that is in contact with the material body is adjacent to the outside face of the wall of the material body. | |
| Inside.InitExtTemperature / InitExtT | Input | Initial temperature adjacent to inside face of the wall. Only used if Reset of the Material Body model or Reset of the whole project is performed. |
| Inside.Temperature / T | Input/Calc | Current temperature adjacent to inside face of the wall. Will be a calculated field if ConnectionTo = Inside Face. |
| Outside.InitExtTemperature / InitExtT | Input | Initial temperature adjacent to outside face of the wall. Only used if Reset of the Material Body model or Reset of the whole project is performed. |
| Outside.Temperature / T | Input/Calc | Current temperature adjacent to outside face of the wall. Will be a calculated field if ConnectionTo = Outside Face. |
| Connection - The following fields are only visible if ExternalEffect is enabled or pipes are connected to the Material Body model. | ||
| V_A_Ratio | Input | The ratio of fluid volume at the interface to heat transfer area. |
| Stream.Qm | Input/Calc | The mass flow of the fluid at the interface. If pipes have been connected to the Material Body model this will be a calculated field equal to Qo.Qm (MassFlow) of the combined connected feed stream/s. |
| Stream.T | Input/Calc | The temperature of the fluid at the interface. If pipes have been connected to the Material Body model this will be a calculated field equal to Qo.T (Temperature) of the combined connected feed stream/s. |
| Stream.HzIn | Input/Calc | The specific enthalpy (including phase change) of the fluid at the interface. If pipes have been connected to the Material Body model this will be a calculated field equal to Qo.Hz@T of the combined connected feed stream/s. |
| Stream.Density / Rho | Input/Calc | The density of the fluid at the interface. If pipes have been connected to the Material Body model this will be a calculated field equal to Qo.Rho (Density) of the combined connected feed stream/s. |
| Stream.CpAvg | Input/Calc | The average specific heat capacity of the fluid at the interface from 0°C to the feed temperature. If pipes have been connected to the Material Body model, this will be a calculated field and based on the properties of the connected feed stream/s. In most cases, this will be similar or equal to Qo.Cp@T of the combined connected feed stream/s. It may not be the same as it is an average value from 0°C to the feed temperature. |
| Stream.Hz0 | Input/Calc | The specific enthalpy (including phase change) at 0°C of the fluid at the interface. If pipes have been connected to the Material Body model this will be a calculated field based on the properties of the combined connected feed stream/s. |
| Stream.totHz0 | Calc | The enthalpy (including phase change) at 0°C of the fluid at the interface. If pipes have been connected to the Material Body model this will be a calculated field based on the properties of the combined connected feed stream/s. |
| Stream.SrcPwr | Input | The power input as a result of reactions in the fluid at the interface. |
| Stream.PwrIn | Calc | The initial enthalpy (including phase change), from 0°C to stream temperature of the fluid at the interface. If pipes have been connected to the Material Body model this will be equal to Qo.totHz of the combined connected feed stream/s. |
| Stream.PwrOut | Calc | The final enthalpy (including phase change), from 0°C to stream temperature of the fluid at the interface. If pipes have been connected to the Material Body model this will be equal to Qo.totHz of the connected product stream. |
| Connected.ProdT | Calc | The product temperature of the connected stream. |
| Connected.HeatToWall | Calc | Heat transferred (by convection) from the connected stream to the relevant wall of the material body. |
Adding this Model to a Project
Add to Configuration File
Sort either by DLL or Group:
| DLL: | MatHand2.dll |
→ | Units/Links | → | Material Handling: Material Body | |
| or | Group: | Mass Transfer |
→ | Units/Links | → | Material Handling: Material Body |
See Model Selection for more information on adding models to the configuration file.
Insert into Project Flowsheet
| Insert Unit | → | Material Handling | → | Material Body |
See Insert Unit for general information on inserting units.