modelPressurizer
Extends from TRANSFORM.Fluid.Volumes.BaseClasses.BaseDrum.PartialDrum2Phase (partial two phase drum model).
Information
Spray stream is assumed to be saturated liquid. This means there is no equation for condensing due to spray.... this was causing solver problems... Should be addressed.
This model describes the cylindrical drum of a drum boiler, without assuming thermodynamic equilibrium between the liquid and vapour holdups. Connectors are provided for surgePort inlet, steamPort outlet, downcomer outlet, riser inlet, and blowdown outlet.
The model is based on dynamic mass and energy balance equations of the liquid volume and vapour volume inside the drum. Mass and energy tranfer between the two phases is provided by bulk condensation and surface condensation of the vapour phase, and by bulk boiling of the liquid phase. Additional energy transfer can take place at the surface if the steamPort is superheated.
The riser flowrate is separated before entering the drum, at the vapour pressure. The (saturated) liquid fraction goes into the liquid volume; the (wet) vapour fraction goes into the vapour volume, vith a steamPort quality depending on the liquid/vapour density ratio and on the avr parameter.
The enthalpy of the liquid going to the downcomer is computed by assuming that a fraction of the total mass flowrate (afd) comes directly from the surgePort inlet. The pressure at the downcomer connector is equal to the vapour pressure plus the liquid head.
The metal wall dynamics is taken into account, assuming uniform temperature. Heat transfer takes place between the metal wall and the liquid phase, vapour phase, and external atmosphere, the corresponding heat transfer coefficients being gl, gv, and gext.
The drum level is referenced to the centreline.
The start values of drum pressure, liquid specific enthalpy, vapour specific enthalpy, and metal wall temperature can be specified by setting the parameters p_start, h_liquid_start, h_vapor_start, Tmstart
Modelling options
The following options are available to specify the orientation of the cylindrical drum:
DrumOrientation = 0: horizontal axis.DrumOrientation = 1: vertical axis.
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| Geometry | |||
| SI.Volume | V_total (from PartialDrum2Phase) | Total volume (liquid + vapor) | |
| Assumptions | |||
| Boolean | allowFlowReversal (from PartialDrum2Phase) | system.allowFlowReversal | = true to allow flow reversal, false restrics to design direction |
| Assumptions › Dynamics | |||
| Types.Dynamics | energyDynamics (from PartialDrum2Phase) | system.energyDynamics | Formulation of energy balance |
| Types.Dynamics | massDynamics (from PartialDrum2Phase) | system.massDynamics | Formulation of mass balance |
| Initialization | |||
| TRANSFORM.Units.NonDim | Vfrac_liquid_start (from PartialDrum2Phase) | 0.5 | Initial fraction of volume in the liquid phase |
| SI.Pressure | p_start (from PartialDrum2Phase) | system.p_start | Pressure start value |
| SI.SpecificEnthalpy | h_liquid_start (from PartialDrum2Phase) | Medium.bubbleEnthalpy(Medium.setSat_p(p_start)) | Liquid specific enthalpy start value |
| SI.SpecificEnthalpy | h_vapor_start (from PartialDrum2Phase) | Medium.dewEnthalpy(Medium.setSat_p(p_start)) | Vapour specific enthalpy start value |
Connectors
| Type | Name | Default | Description |
|---|---|---|---|
| Interfaces.FluidPort_State | surgePort | ||
| Interfaces.FluidPort_State | sprayPort | ||
| Interfaces.FluidPort_State | steamPort | ||
| Modelica.Thermal.HeatTransfer.Interfaces.HeatPort_a | vaporHeater | ||
| Modelica.Thermal.HeatTransfer.Interfaces.HeatPort_a | liquidHeater | ||
| Modelica.Thermal.HeatTransfer.Interfaces.HeatPort_a | heatPort_WV | ||
| Modelica.Thermal.HeatTransfer.Interfaces.HeatPort_a | heatPort_WL |
Components
| Type | Name | Default | Description |
|---|---|---|---|
| Modelica.Fluid.System | system (from PartialDrum2Phase) | System properties | |
| SI.Pressure | p (from PartialDrum2Phase) | Surface pressure | |
| SI.Volume | V_vapor (from PartialDrum2Phase) | Volume occupied by vapour | |
| SI.Volume | V_liquid (from PartialDrum2Phase) | Volume occupied by liquid | |
| TRANSFORM.Units.NonDim | Vfrac_liquid (from PartialDrum2Phase) | Fractional of total volume occupied by liquid | |
| Medium.ThermodynamicState | state_liquid (from PartialDrum2Phase) | Medium.setState_ph(p, h_liquid) | Liquid state |
| SI.Density | rho_liquid (from PartialDrum2Phase) | Medium.density(state_liquid) | Liquid density |
| SI.SpecificEnthalpy | h_liquid (from PartialDrum2Phase) | Liquid specific enthalpy | |
| SI.Temperature | T_liquid (from PartialDrum2Phase) | Medium.temperature(state_liquid) | Liquid temperature |
| Medium.ThermodynamicState | state_vapor (from PartialDrum2Phase) | Medium.setState_ph(p, h_vapor) | Vapor state |
| SI.Density | rho_vapor (from PartialDrum2Phase) | Medium.density(state_vapor) | Vapor density |
| SI.SpecificEnthalpy | h_vapor (from PartialDrum2Phase) | Vapor specific enthalpy | |
| SI.Temperature | T_vapor (from PartialDrum2Phase) | Medium.temperature(state_vapor) | Vapor temperature |
| Medium.SaturationProperties | sat (from PartialDrum2Phase) | Medium.setSat_p(p) | State vector to compute saturation properties |
| SI.SpecificEnthalpy | h_gsat (from PartialDrum2Phase) | Medium.dewEnthalpy(sat) | Saturated vapor specific enthalpy |
| SI.SpecificEnthalpy | h_fsat (from PartialDrum2Phase) | Medium.bubbleEnthalpy(sat) | Saturated liquid specific enthalpy |
| SI.Temperature | Tsat (from PartialDrum2Phase) | sat.Tsat | Saturation temperature |
| SI.Energy | U_liquid (from PartialDrum2Phase) | Internal energy of liquid | |
| SI.Mass | m_liquid (from PartialDrum2Phase) | Mass of liquid | |
| SI.MassFlowRate | mb_flow_liquid (from PartialDrum2Phase) | Mass flows across liquid boundaries | |
| SI.EnthalpyFlowRate | Hb_flow_liquid (from PartialDrum2Phase) | Enthalpy flow across liquid boundaries or energy source/sink | |
| SI.HeatFlowRate | Qb_flow_liquid (from PartialDrum2Phase) | Heat flow across liquid boundaries or energy source/sink | |
| SI.Power | Wb_flow_liquid (from PartialDrum2Phase) | Work flow across liquid boundaries or source term | |
| SI.Energy | U_vapor (from PartialDrum2Phase) | Internal energy of vapor | |
| SI.Mass | m_vapor (from PartialDrum2Phase) | Mass of vapor | |
| SI.MassFlowRate | mb_flow_vapor (from PartialDrum2Phase) | Mass flows across vapor boundaries | |
| SI.EnthalpyFlowRate | Hb_flow_vapor (from PartialDrum2Phase) | Enthalpy flow across vapor boundaries or energy source/sink | |
| SI.HeatFlowRate | Qb_flow_vapor (from PartialDrum2Phase) | Heat flow across vapor boundaries or energy source/sink | |
| SI.Power | Wb_flow_vapor (from PartialDrum2Phase) | Work flow across vapor boundaries or source term | |
| DrumType | drumType | ||
| BulkEvaporation | bulkEvaporation | ||
| BulkCondensation | bulkCondensation | ||
| MassTransfer_VL | massTransfer_VL | ||
| HeatTransfer_VL | heatTransfer_VL | ||
| HeatTransfer_WL | heatTransfer_WL | ||
| HeatTransfer_WV | heatTransfer_WV | ||
| SI.MassFlowRate | W_surge | Mass flowrate of surgePort | |
| SI.SpecificEnthalpy | h_surge | Specific enthalpy of surgePort | |
| SI.MassFlowRate | W_steam | Mass flowrate of steamPort | |
| SI.SpecificEnthalpy | h_steam | Specific enthalpy of steamPort | |
| SI.MassFlowRate | W_spray | Mass flowrate of sprayPort | |
| SI.SpecificEnthalpy | h_spray | Specific enthalpy of sprayPort | |
| SI.Height | level | drumType.level | Measured fluid level |
| SI.Area | A_surfaceWTotal | drumType.A_surfaceWTotal | Total inner wall surface area of pressurizer |
| SI.Area | A_surfaceWL | drumType.A_surfaceWL | Wall-Liquid interfacial area |
| SI.Area | A_surfaceWV | drumType.A_surfaceWV | Wall-Vapor interfacial area |
| SI.Area | A_surfaceVL | drumType.A_surfaceVL | Vapor-Liquid interfacial area |
| SI.MassFlowRate | W_cBulk | Mass flowrate of bulk condensation | |
| SI.MassFlowRate | W_eBulk | Mass flowrate of bulk evaporation | |
| SI.QualityFactor | x_th_spray | Thermodynamic quality of sprayPort | |
| SI.MassFlowRate | W_cSpray | Mass flowrate of condensate from sprayPort | |
| SI.MassFlowRate | W_vapSpray | Mass flowrate of of liquid after heat/mass balance from sprayPort | |
| SI.MassFlowRate | W_liqSpray | Mass flowrate of of liquid after heat/mass balance from sprayPort | |
| SI.EnthalpyFlowRate | H_cSpray | Mass flowrate of condensate from sprayPort | |
| SI.EnthalpyFlowRate | H_vapSpray | Mass flowrate of of liquid after heat/mass balance from sprayPort | |
| SI.EnthalpyFlowRate | H_liqSpray | Mass flowrate of of liquid after heat/mass balance from sprayPort | |
| SI.MassFlowRate | W_vl | Mass flowrate from vapor-liquid interface model | |
| SI.Power | Q_vl | Heat transfer at vapor-liquid interface | |
| SI.Power | Q_wl | Heat transfer at wall-liquid surface | |
| SI.Power | Q_wv | Heat transfer at wall-vapor surface | |
| SI.QualityFactor | x_th_liquid | Thermodynamic quality of liquid region | |
| SI.QualityFactor | x_abs_liquid | Absolute quality of liquid region | |
| SI.QualityFactor | x_th_vapor | Thermodynamic quality of vapor region | |
| SI.QualityFactor | x_abs_vapor | Absolute quality of liquid region |
Contents
| Name | Description |
|---|---|
| DrumType | 1. Select model 2. Set parameters (Total volume must match V_total) |
| BulkEvaporation | Vapor bubble transport from liquid to vapor phase |
| BulkCondensation | Liquid droplet transport from vapor to liquid phase |
| MassTransfer_VL | Vapor-liquid interface mass transport coefficient |
| HeatTransfer_VL | Vapor-liquid interface heet transfer coefficient |
| HeatTransfer_WL | Wall-vapor heat transfer coefficient |
| HeatTransfer_WV | Wall-liquid heat transfer coefficient |
Revisions
<htm_liquid>
<ul>
<li><i>30 May 2005</i>
by <a href="mailto:francesco.casella@polimi.it">Francesco Casella</a>:<br>
Initialisation support added.</li>
<li><i>16 Dec 2004</i>
by <a href="mailto:francesco.casella@polimi.it">Francesco Casella</a>:<br>
Standard medium definition added.</li>
<li><i>5 Jul 2004</i>
by <a href="mailto:francesco.casella@polimi.it">Francesco Casella</a>:<br>
Adapted to Modelica.Media.</li>
<li><i>1 Feb 2004</i>
by <a href="mailto:francesco.casella@polimi.it">Francesco Casella</a>:<br>
Improved equations for drum geometry.</li>
<li><i>1 Oct 2003</i>
by <a href="mailto:francesco.casella@polimi.it">Francesco Casella</a>:<br>
First release.</li>
</ul>