Problem: (Ex. 6.3 pg 193 de Nevers) Two reservoirs are connected by 2000 ft of 3-in schedule 40 pipe (carbon steel). (See diagram below) Water is to be pumped at a rate of 200 gallons per minute from one reservoir to the other. An Aspen Plus Simulation will be created to find the required pump power and the required pump pressure rise for this scenario. Same Level 2000 ft 3-in Schedule 40 PUMP Aspen Plus Setup for Pump/Pipe Flow Simulation Click „ok‟ Another window will appear indicating that the connection is established. Click „ok‟ Click on the diamond button next to the “Create a new run” option. Then click ok. In this pump/pipe flow simulation, aspen plus will calculate the required pump pressure rise and pump power. Select general with metric units for the application type and flowsheet simulation for the run type. To do this, click on the box and a list of options will appear. Select the appropriate choice. Click ok when finished. To start the Pump/Pipe flow simulation, create a feed arrow as shown. To create the pump, click on the Pump/Comp selection in the Type menu and the Pump selection in the Model menu. Also, select the ICON1 option in the Icon menu. When the ID box appears, label the pump “PUMP-1.” To choose the pipe, select the Pipe/Valve option in the Type menu and the Pipe option in the Model menu. Choose the H-PIPE selection from the Icon menu. When the ID box appears after creating the pipe, name it “P-1.” Now create a product arrow. Connect everything together as shown on the left. Label the stream from the feed arrow to the pump as “FEED,” and the stream from the pump to the pipe as “OUT.” Then label the stream from the pipe to the product arrow as “PROD.” When completed click on the next button. Click on “ok”. This screen will appear next. Click on the title field and give this project a title. Also, in the flow/frac options, select the nomoleflow, and stdvolflow, options by right clicking on the appropriate boxes. For example, to select the nomoleflow option, right click on the text “MOLEFLOW.” Left click on the molefrac option. Also at the bottom of the window, right click on the Flow-Basis box and select the STDVOL option. Your screen should match the diagram on the left. Click on the next box to continue. Only water will be entered here. In the column labeled component name, type water in the first space. Press enter and the formula and type columns will fill in with the appropriate data. Then on the same row of the water data, click on the comp ID column. You will need to name the component with a short, concise name. This name will appear in the report generated by Aspen so use an easily recognizable name. Click the next box. In this window, only one parameter needs to be changed. Right click in the box labeled Opsetname and choose NRTL from the menu. Click the next box to continue. Click on the ok button Enter the data here for the inlet stream (FEED). This stream contains liquid water, so select 50 deg F for the temp. and 14.7 psi for the pressure. In the box labeled H2O, enter the value 200. Notice the units of the values you just entered in the box labeled composition basis. These units can be changed by first right clicking on the box and selecting the appropriate units from the options. For this example select GAL/MIN. Click next. The information about the pipe will be entered in here. First, enter in the length of pipe, 2000 ft, and enter in the type of material. Right click on the Material box and select carbon-steel. Then right click on the Schedule box and select 40. Next, right click on the Nom-Diam box and select 3-IN. Note how the In-Diam box automatically fills in. Finally, in the Type box under the Thermal Information, right click and select the ADIABATIC option. Click next. This window shows that all of the required forms are complete. Incomplete forms would appear in red. Click next. In the Pres box, enter 100. This value is only a guess. Eventually, this value will be used in an iteration to determine the pressure drop across the pump. Click cancel. More input is to be entered. Now we are going to have Aspen Plus iterate to find the pressure at the pump outlet. We are going to use the design –spec option. Please refer to the design- spec manual for further detail. Go to the Forms menu at the top of the page. Select Flowsheet Options and then the Design-Spec option. Click on the create button. This box will appear with the default ID of “DS-1.” This default value is appropriate for this example. Click „ok.‟ The data for the Design-Spec function will now be entered. Click next. This page is used to specify the outlet pressure. Because both reservoirs in the example problem are at atmospheric pressure, we can use one of these known values to find the pump outlet pressure. For this example we will use the outlet pressure. In the Varname box, enter in the name „PRES.‟ Then right click on the Vartype box and select the „STREAM-VAR.‟ Next, right click on the Stream box and select „PROD.‟ Press enter and the Substream box will automatically select „MIXED.‟ Finally, right click on the Variable box and select „PRES.” Click next to continue. Now we will setup Aspen Plus to find the pump outlet pressure. Right click on the Spec box and select „PRES.‟ Then click on Target box and enter 14.7; click on the Tolerance box and enter 0.01. Right click on the Vartype box and select „BLOCK-VAR.‟ Next, in the Block box, right click and select „PUMP-1.‟ Also, right click in the Variable box and select the „PRES‟ option; the Sentence box will automatically fill in. Finally, enter the manipulated variable limits. In the Lower box enter 14.7 and enter in the Upper box 200. Click next. This window indicates that all required input is complete, otherwise some of the items would appear in red. Click next. Click on „ok.‟ Click on the „Results.‟ This screen shows that the calculations were completed normally. If the calculations were completed with errors, click on the status to try to determine the source of error. Click on the double right arrows at the top of the page. This will bring you to a results page. These are the results from the simulation. Click on the right double arrow to view the additional results. To view the required pump power and the pump pressure rise, click on the right double arrow until the (Pump.Results) appears. This page displays the required horsepower and pressure rise for the pump. The calculated power was 8.9 hp and the pressure rise was 77.12 psi.
Pages to are hidden for
"Aspen Plus Setup for a PumpPipe Flow Process Problem _Ex 63 pg "Please download to view full document