modelGasStorage_varXi_L2
Extends from Base.PartialGasStorage_L2 (Partial model of a simple gas storage volume for real gases).
Information
1. Purpose of model
This model represents a compressed gas storage for real gases with variable composition. It extends Base.PartialGasStorage_L2.
2. Level of detail, physical effects considered, and physical insight
The model consists of a volume, in which the gas located. Pressure losses inside the volume and during charging and discharging are neglected. There is no discretisation of the flow field or the heat transfer. The heat transfer is modelled using a replacable heat transfer model, the default model uses a constant heat transfer coefficient. The parameter variableCompositionEntries can be used in case that not all components are freely variable, e.g. when hydrogen is fed into natural gas. This reduces the number of states.
3. Limits of validity
The model is only valid for negligible pressure losses and negligible changes of the heat transfer coefficient (other heat transfer models can be used). For high pressures there are errors due to errors in the gas models. The gas in the storage is always ideally mixed, there is only one composition in the storage.
4. Interfaces
gasPortIn and gasPortOut: Real gas input and output
heat: heat port for the heat flow into/out of the storage
p_storage: signal output of the gas pressure
5. Nomenclature
(no elements)
6. Governing Equations
Simple mass and energy balances are used. For the compositions, component mass balances are added.
7. Remarks for Usage
(no remarks)
8. Validation
This model is not validated and might produce different results depending on the energy balance equation used in the base model.
9. References
(no remarks)
10. Version History
Model created by Carsten Bode (c.bode@tuhh.de) in Apr 2017
Modeli modified by Carsten Bode (c.bode@tuhh.de) in Apr 2021 (added simplifications for composition)
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| SI.SpecificEnthalpy | NCV (from PartialGasStorage) | TransiEnt.Basics.Functions.GasProperties.getRealGasNCVVector(medium, medium.nc) | NCV of gas components |
| SI.SpecificEnthalpy | GCV (from PartialGasStorage) | TransiEnt.Basics.Functions.GasProperties.getRealGasGCVVector(medium, medium.nc) | GCV of gas component |
| SI.Diameter | diameter (from PartialGasStorage_L2) | sqrt(4*V_geo/(pi*height)) | Diameter of storage |
| SI.Area | A_heat (from PartialGasStorage_L2) | pi/2*diameter^2 + pi*diameter*height | Surface area of storage |
| Integer[:] | dependentCompositionEntries | if variableCompositionEntries[1] == 0 then 1:medium.nc else TransiEnt.Basics.Functions.findSetDifference(1:medium.nc, variableCompositionEntries) | Entries of medium vector which are supposed to be dependent on the variable entries |
| Fundamental Definitions | |||
| TILMedia.VLEFluidTypes.BaseVLEFluid | medium (from PartialGasStorage) | simCenter.gasModel1 | Medium in the gas storage |
| Boolean | includeHeatTransfer (from PartialGasStorage) | true | consider heat transfer |
| Integer[:] | variableCompositionEntries | {0} | Entries of medium vector which are supposed to be completely variable |
| SI.MassFraction[medium.nc - 1] | xi_nom | medium.xi_default | Constant composition |
| Geometry | |||
| SI.Volume | V_geo (from PartialGasStorage) | 1 | geometric inner volume of the storage cylinder |
| SI.Height | height (from PartialGasStorage_L2) | 3.779*V_geo^(1/3) | Height of storage |
| Initialization | |||
| SI.Mass | m_gas_start (from PartialGasStorage) | 1e5 | Initial mass in the storage |
| Boolean | start_pressure (from PartialGasStorage_L2) | true | true if a start pressure is defined, false if a start mass is defined |
| SI.Pressure | p_gas_start (from PartialGasStorage_L2) | 1e5 | pressure in storage at t=0 |
| SI.ThermodynamicTemperature | T_gas_start (from PartialGasStorage_L2) | 283.15 | Temperature of gas in storage at t=0 |
| SI.MassFraction[medium.nc - 1] | xi_gas_start | medium.xi_default | Mass composition of gas in storage at t=0 |
| Statistics | |||
| Boolean | calculateCost (from PartialGasStorage) | simCenter.calculateCost | true if cost shall be calculated |
Connectors
Components
| Type | Name | Default | Description |
|---|---|---|---|
| TransiEnt.SimCenter | simCenter (from PartialGasStorage) | ||
| TransiEnt.ModelStatistics | modelStatistics (from PartialGasStorage) | ||
| SI.Mass | m_gas (from PartialGasStorage) | Gas mass | |
| SI.MassFraction[medium.nc - 1] | xi_gas (from PartialGasStorage) | Gas composition | |
| SI.EnergyFlowRate | H_flow_in_NCV (from PartialGasStorage) | Inflowing enthalpy flow based on NCV | |
| SI.EnergyFlowRate | H_flow_out_NCV (from PartialGasStorage) | Inflowing enthalpy flow based on NCV | |
| SI.Enthalpy | H_gas_NCV (from PartialGasStorage) | Enthalpy of the gas bulk based on NCV | |
| SI.EnergyFlowRate | H_flow_in_GCV (from PartialGasStorage) | Inflowing enthalpy flow based on GCV | |
| SI.EnergyFlowRate | H_flow_out_GCV (from PartialGasStorage) | Inflowing enthalpy flow based on GCV | |
| SI.Enthalpy | H_gas_GCV (from PartialGasStorage) | Enthalpy of the gas bulk based on GCV | |
| HeatTransfer | heatTransfer (from PartialGasStorage_L2) | ||
| Summary | summary |
Contents
| Name | Description |
|---|---|
| Outlineprotected | |