Ammonia Project 137
This section is for SysCAD build 137 or earlier. For the project description in the latest version, please see Demo Ammonia Project
This is a Steady State project and is stored at:
..\SysCADXXX\Examples\15 Ammonia\Demo Ammonia Project.spf
- Shows the use of Compressor
- Shows how to flash/condense NH3 using VLE
- Shows the use of Simple Heaters
- Shows the use of Shell and Tube Heat Exchanger in Fully Evaporating Mode.
- Shows the use of Simple Condenser
- Shows the use of Simple Heat Exchanger
Brief Project Description
This is a very simplified ammonia plant. It is used to demonstrate how to simulate complex unit operation by using multiple simple unit operations.
- The reformer is simulated using two Ties unit operations with sub models to handle reactions on both sides as well as heat transfer.
- The Evaporator - Flash Vessel - Catch_Pot operations demonstrate how to flashing/condensing NH3 using VLE. The use of VLE will ensure the partial pressures are correct within the unit operation. (This is much more preferable than using a reaction block with forced extents.)
- Many other unit operations are simulated using Tie/Tank with reaction sub model for component change
- various other heat exchangers are simulated using simple heaters for heat gain/loss.
SysCAD 9.3 Build 137 and Earlier
- Setting up VLE data for components other than water
- One focus of this example is to show user how to add in flashing/condensing data for their project, to do so, user must first set up the Vapour & Liquid Data in the Species Database:
- Edit the SysCAD.93.db3 file to contain the component requiring flashing/condensing.
- Make sure the component exist in both (l) and (g) form.
- Make sure the Vapour Properties are fully specified for the Gas component, that is, the Vapour Pressure and Critical data are defined. (As per NH3(g) entry in the example project.)
- In the project, user can switch on the VLE sub model where flashing is required, change the Component to the required component. (In this example, NH3. See Evaporator, Flash_Vessel or Catch_Pot in the project.)
- SysCAD will calculate the VLE based on the pressure in the vessel.
- Setting up Shell and Tube Heat exchanges in Fully Evaporating Mode
- Another focus of this example is to show user how to set up Heat Exchanger in Fully Evaporating mode
- Evaporation will occur in the Shell Side only, make sure the stream requiring evaporation is connected corrected. (Project examples are Boiler and Evaporator)
- Set RqdOpMode to Fully Evaporating
- Define Area, HTC and ApproachDT
- Setting up Simple Heat Exchanger
- The Simple Heat Exchanger Model works out the flow conditions (for one side) based on the user defined dT information. See Ammonia_Cooler in the project.
- SimpleHX Tab
- Define the required Ammonia outlet temperature
- Select Other.CalcFlow On
- Calc Tab
- DemandConnection set to General Demand, this will allow SysCAD to work out and set the cooling water flowrate. (The Cooling_Water Feeder must be placed into Demand mode for this to work.)
- Define the required Cooling Water temperature
- Cooling Water Supply Feeder
- The Cooling_Water Feeder in this project will provide water demanded by Ammonia Cooler.
- FeederSink (or Feed_XPG-1) Tab, Select Demand.On, check that Demand.Max will cover the flowrate range for the project. Increase this value if necessary.
- Qm_Rqd will represent the minimum value for the steam supply. If this value is higher than downstream requirements, the excess amount is distributed. Recommend using a small number of this field.
- Define the operating condition and composition.
- SysCAD will calculate the feed flowrate and display it in the Results:Flow Conditions Qm field.
Included Excel Report
- Example Plant Criteria Report, used to set data into SysCAD as well as reporting back the actual values from SysCAD.
- Example Reactions Report detailing all the reaction and reaction extents used in the project.
- Example Stream Report