00:00As discussed earlier, before starting the simulation, make sure that DWSim software is
00:09installed on your computer. Step 1, open DWSim. From the desktop, select start and then select
00:17programs. Next, select DWSim folder and then DWSim. DWSim welcome window appears as shown here.
00:24Step 2, complete simulation configuration wizard. As discussed earlier, a new simulation is started by
00:33initializing the simulation configuration wizard by either clicking on the new chemical
00:38process model under the file menu or by clicking the new steady state simulation button on the
00:44button strip or by clicking the link create new under process modeling scene on the welcome screen.
00:50An introduction window will open as shown. Click the next button to get the compounds page.
00:56Start adding the components. Make sure that the components added are water and methanol. Click
01:04next to get the property package sheet. Select at least one property involved. Click add button.
01:10Rawls law is the recommended package for this problem. Click the next button to get to the
01:17system of units page. Select the units according to the problem statement one after another for all
01:24the properties given in the problem. For other properties, just leave it as it is. Make sure
01:31that the units for pressure as bar, temperature as degree Celsius and mass flow rate as kilogram
01:36per hour or selector. Click next to get the behavior page. Then click on activate smart object solving and then
01:45click the finish button. This completes the simulation configuration and now it is ready to construct the
01:51flow sheet. Step 3. Draw the flow sheet. On the main flow sheet window, a flow sheet can be drawn by using the
01:59process equipment models available. From the object palette that appears at the bottom of the flow sheet,
02:05choose exchanger then select the required heat exchanger. Drag and drop the heat exchanger on the flow sheet and
02:13double click on the objects to edit the names. Since smart object solving is already selected,
02:20it will automatically add all the necessary feed product and energy streams associated with it, but
02:26with the default names for the object and numbers for the streams. Here the streams are renamed as water in,
02:33methanol in, water out, methanol out and the block as heat exchanger. Step 4 is to provide stream information.
02:42Just double click on the water in stream to edit and enter all the properties from the problem statement
02:49highlighted. Note that there are two tabs, namely stream conditions and compound amounts. The basis and
02:57the units must be checked thoroughly. Similarly, provide stream information for other streams also. Just
03:05double click on the methanol in stream to edit and enter all the properties from the problem statement as
03:11appear on the screen. As only temperature and pressure are available for the feed, the flash calculation type
03:16can be chosen as temperature and pressure TP. Note that there are two tabs, namely stream conditions and
03:23compound amounts as shown here. The basis and units are checked thoroughly. The stream conditions and
03:30compositions are entered as given in the problem statement. Step 5, configure the block. Double click on the block heat exchanger and enter all the information as
03:38given here. Make sure that the inlet and outlet streams are counted properly. Select the calculation type as calculate outlet temperatures. After entering all the values, click enter key to save the values. Select the flow direction as counter current. Enter the cold fluid pressure drop as point zero zero three bar. Enter the hot fluid pressure drop as point zero three bar. Enter the global heat transfer coefficient as four
03:43440 Watt per meter square Kelvin.
03:46and enter the heat transfer coefficient as 440 Watt per meter square Kelvin.
03:50and enter the heat transfer coefficient as 440 Watt per meter square Kelvin.
03:55Enter the final step.
04:16The final step is to run the simulation and view the results. Once entering all
04:23the values the message will automatically appear as the flow sheet
04:27was calculated successfully which is displayed at the bottom of the
04:30screenshot. Since all the necessary information is completely provided in
04:35this case the flow sheet is automatically calculated. Otherwise the simulation can
04:40be run by clicking the solve button which will trigger an error message. On
04:46rectifying these errors the flow sheet will be calculated successfully. As we
04:51had already discussed on our reports are generated the results are tabulated
04:56using the insert table option from the insert menu. Upon double clicking the
05:00button generator we have to choose the properties to display in the table. For
05:06the property table the object heat exchanger is chosen and the properties
05:12to be tabulated are outlet temperatures, LMTD, thermal efficiency and design
05:17specification parameters including number of tubes, tube length, tube size, pitch etc.
05:23The properties listed here are to be determined as per problem statement. For
05:29the master property table all the inlet and outlet streams were chosen and the
05:34properties selected were temperature, pressure, mass and molar flow rates. These
05:38tables and process flow diagram can be moved by dragging or resizing by zooming
05:44in and out as per our need. Zooming can be done either through a mouse wheel or zoom
05:49buttons. Here the PFD property table and master property tables are neatly
05:55arranged as shown. The simulation work can be saved and the results can be exported
06:01if required. The flow sheet or the result table or any other graphics can be copied so
06:07that it can be pasted into any Microsoft Office application as usual. If needed any of
06:12the input data can be modified to rerun the simulation. With this we have completed
06:17the simulation. Let us summarize what we have learned. We have discussed the steps to
06:23simulate heat exchanger using DWCM software. By this we have come to the end of
06:28this topic. Let us meet in another interesting session. Thank you learners. Click on
06:34learn button to know more and click on the try button to have and so on experience.
