1. Brief overview including program strength and history

Transcription

1 1. Brief overview including program strength and history WinGEMS is a product of Pacific Simulation and is based on the GEMS software initially developed at the University of Idaho Chemical Engineering Department. The initial GEMS software was started in the 60 s and resulted in a mainframe version sold by In 1984 GEMS was released on the PC as PCGEMS. In 1991 Pacific Simulation leased the GEMS modules from the Idaho Research Foundation and developed the initial release of WinGEMS 1.0 on contract to the James River Corporation. This initial prototype served as the basis for the first commercially available release, WinGEMS 2.0, which was released in The current version of WinGEMS, WinGEMS 4.5, was released in November of The strength of WinGEMS 4.5 is its ease-of-use interface coupled with a large standard library of over 60 process modules containing 140 thoroughly tested process block options. WinGEMS was developed by process engineers in the pulp and paper industry to solve industry specific problems. This makes WinGEMS 4.5 ideally suited for full mill analysis of water, fiber, energy, and major and minor process elements, including non-process elements. Following is a listing of the major process blocks along with a short description of each block. All these process blocks are included in the standard version WinGEMS 4.5. Most of these blocks include multiple options. For example, the DRYER block has six options representing different configurations of drum dryers, flash pulp dryers, infrared dryers and airfoil dryers. CHARGE - chemical charge Charge a chemical stream based on the flow of pulp or liquor. Charge bleach chemicals in the bleach plant. Charge white liquor to digester(s). Charge oxidized white liquor to oxygen delignification process. CLF - clarifier Simple clarifier model (e.g. green and white liquor clarifiers). CND - steam condenser Calculate how much cold water is required to condense steam given a temperature difference between the condensate and the outlet water. COMB - combuster Model the combustion of a fuel by an oxidant to produce heat. Required amounts of fuel, oxidant or energy are calculated depending on the option used. COMMIN - comminution calculations for refiners

2 Calculate the outlet shive content, fiber size distribution and freeness of a chip or fiber stream as a function of applied specific energy, the inlet fiber size distribution and the inlet freeness. CTRL - control liquor flows and compositions Control certain stream characteristics by manipulating another stream or block parameter in the system. For example, this block can be used to control effective alkali of white liquor by adjusting chemical make-up, or control the pulp to liquor ratio. DESUP - desuperheater Desuperheat steam by adding water. DILUTE - dilution of one stream with another Reduce the consistency of a stream containing suspended solids. DRYER - dry paper or wood solids with steam and/or hot gases. Calculate the mass and energy balance around dryer units including steam heated drums, yankee dryers, direct contact drying, infrared dryers and airfoils. EECTRL - evaporator evaluation controller Works with LTV block to control input steam. EVAPS - simplified model for evaporation Remove water from liquor or pulp. Does not perform energy balances. FLASH - flash water to steam Flash steam from a liquid stream with the added ability to send volatile components with the flashed stream. GMIX - gas and steam mixer Mix air, steam and other gases together. GREC - gas recovery unit Precipitator or scrubber. Solids components are removed from a gas stream. Can be used as recovery boiler precipitator or scrubber, lime kiln scrubber or TRS scrubber. HEADER - steam header Distribute steam to parallel evaporator effects. HEATD - heat exchanger design Countercurrent heat exchanger model calculates the required area with a specified heat transfer coefficient and temperature criteria. Used for design purposes.

3 HEATX - countercurrent heat exchanger A liquid-liquid or steam-liquid countercurrent heat exchanger HREC - heat recovery Produce steam from heat energy. Represents steam side of boiler, economizer, superheater. Can be used in conjunction with the COMB block. KFURN - kraft recovery furnace Compute the material and energy balance for a kraft recovery furnace. LKILN - lime kiln Rotary lime kiln used for calcining lime mud to produce lime. LTV - liquid to vapor evaporator body Evaporator body (LTV, falling film, etc.) MGSFURN - magnesium furnace Furnace in magnesium sulfite mill. Converts dissolved magnesium to solid MgSO 4 in the stack gas. Dissolved Na, SO 4, S and Cl are also converted to solids in the stack gas. MIX - mix two or more streams Mix 2 to 48 streams. MIX has the ability to set sorption "on" or "off" for the pulp streams entering and leaving. PBOIL - power boiler Calculate energy recovered from burning hog fuel, coal, oil or gas, or calculate amounts of fuel required to produce a specified amount of energy. PDROP - pressure drop Reduce the pressure of steam streams (such as pressure losses due to flow through pipes and fittings) PEROX - peroxide bleaching Estimate bleach response in alkaline hydrogen peroxide bleaching of mechanical pulps. Consumption of peroxide by dissolved solids and extractives as well as decomposition caused by alkali are taken into account. PPPAC - pulp physical property package Calculate the hand sheet physical properties for mechanical pulps and mechanical pulp/kraft pulp mixtures. PRESS - screw press

4 Standard screw press or a washing screw press. Use either the dilution - mixing model or the displacement washing model for washing. PUMP - pump Specify a pressure change for either a liquid or gas stream, the energy required is calculated. Gas streams may be expanded as well as compressed. REACT - chemical reaction Generalized reactor block. Simulate different types of reactions with this block. One is the conversion of wood to dissolved wood solids generating heat in the process such as a digester or bleach plant yield loss. A second is the conversion of one chemical species to another such as sulfide to sulfate in black liquor oxidation. REACTION chemical reaction Used to convert mass of specific stream components into other components. Common reactions include the dissolution of pulp, conversion of one component to another, or the stoichiometric conversion of several reactant components into product components. An updated and expanded version of the REACT block. REFIN - refiner for chips or fiber Perform the mass and energy balances for a chip or fiber refiner. REFIN will also calculate output fiber size distribution, shive contents and fiber surface area for primary, secondary, tertiary and reject refiners. SCAH - steam coil air heater Steam/air heat exchanger calculates the steam required to heat air. SCREEN - screening and cleaning of mechanical pulps Simulate the fractionation performance of centrifugal screens, vibrating screens, pressure screens and hydrocyclones. SCTRL - scrubber controller Use in conjunction with the scrubber (GREC block) to charge the proper amount of liquor containing caustic. This is established by knowing how much sulfur is entering the scrubber and its efficiency. SDT - smelt dissolving tank Smelt dissolving tank SLAC - slaking and causticizing Slaking and causticizing steps in the kraft liquor preparation cycle. SPLIT - split one stream into two or more streams

5 Split a single stream into two or more streams. Use to model a pipe "T", press, header, decker, paper machine wire, screen, cleaner, etc. SRF - special reactor functions A selection of reactions associated with the combining of sulfur compounds with other liquors. STMIX - steam mixer Direct and indirect heating of a process stream with steam and mixing of two or more steam streams. STOIC - stoichiometric reactor Reactor block for general chemical reaction among dissolved components where the stoichiometry of the reaction is known. SULF - sulfonation of chips or fibers Simulate the effects of sodium sulfite addition to chips, wood fibers and reject fibers. TRC - thermal recompressor for steam streams Calculate the mass and energy balance when high pressure motive steam is injected into low pressure steam to obtain steam of intermediate pressure. TURB - mechanical turbine Turbine for production of power or mechanical energy. Simulates each section between extraction points of an actual turbine. VRC - vapor recompressor for steam streams Mechanical steam compressor WASH - washer Calculate chemical carryover in all types of washers. May be used to simulate the operation of deckers, displacement washers and disk filters as well as lime mud washers. WLCTRL - control white liquor flows and chemical makeups Calculates flows of makeup chemicals to maintain sulfidity and EA or AA on wood for up to four fiber lines. WZONE - wash zone Hi-heat wash zone in a Kamyr digester In addition to the process blocks there are additional blocks included with the standard block set as follows:

6 GRAPH graph A linear graph containing up to four components with iterations (x-axis) vs. component (y-axis). INDICATOR - an indicator to monitor a component An active indicator/meter to monitor a component at the current iteration. SLIDER - manual slider controller A manual operator controller to adjust amount of a specific input stream component during the active WinGEMS simulation. STORE - parameter storage block A specialized non-process block. The parameters of this block provide storage registers which can be referenced from within the simulation. WAIT - delay in simulation A delay in the simulation with the length specified in seconds. Finally there are a set of blocks representing dynamics that are added to the standard block set. These include the following: PID - PID controller Proportional-Integral-Derivative (PID) feedback controller PLUGF - plug flow dynamic delay Model the delay caused by plug flow. Useful for bleach towers, blow tanks, and pipes with long residence times. TANK - well mixed stirred dynamic tank vessel Model the dynamic response caused by a well mixed stirred tank. WinGEMS 4.5 combines ease-of-use with many advanced features and capabilities that allow the user to build steady-state and dynamic simulations with a wide variety of uses and applications. Some of the features in WinGEMS 4.5 include the following: Icons - Process blocks can be represented with process icons. The user can now choose from a set of predefined scaleable icons, or

7 create their own. Stream Browser - When the cursor is placed on a stream, a tool-tips style window displays stream values and units according to a user-defined specification. Stream Tags - Streams can be assigned pre-formatted tags that display the current values of that stream next to it, making it useful for printing final results. Compound Block Import - Compound block types from other projects can be incorporated into an existing project. This allows the development of Libraries of compound blocks that can be shared between users. Also, creation of new projects based on previous projects is easier. Dynamic Text - Dynamic text is text placed on the screen using the Text tool that is specially formatted to reference current process values. Drag and Drop Calculation Order - The calculation order may be easily modified in a drag and drop fashion removing the need to modify the calculation order script manually. Displaying References - The references display is a valuable tool for visually representing information dependencies between objects in a WinGEMS diagram. The references display shows dependencies between four types of objects : Computed and controlled parameters, cut streams, mass copy and info copy streams, and profiled parameters. Hideable, floatable and dockable Execution and Palette toolbars. The new tools have the same look and hold similar positions as the standard Microsoft Office product toolbars, so the user can readily identify the functions. In addition, the toolbar buttons have tool tips (text identifiers) that pop up when the cursor is placed over the button. Brand-new Visual Utilities:

8 Graphs show the change of data with iteration and can track up to 4 variables per graph Sliders allow the user to vary inputs on the fly Indicators show current levels and the user can define the colors. There are vertical, horizontal or meter representations. This feature is particularly good for representing tank levels. Execution Utilities: Wait Block allows the user to slow or speed up the simulation and is especially nice for tracking real-time simulations in dynamics PID Controller is a new block that emulates PID controllers. The current controller in WinGEMS 4.0 is proportional only. The new PID Controller block is a very important tool for dynamic simulations. Metafiles allow the user to copy to the clipboard and to copy and paste a project image into other applications, such as MS Word and MS Excel. Colored Streams and the Stream Appearance Dialog allow the user to change the appearance of individual streams by changing the color and line style PID drawing style Title Boxes and Borders have been included, which allow the user to add title text in the manner customarily seen in engineering piping and instrument drawing style drawings. Excel style computed parameters allow the user to add complicated formulas in Block and Stream Values. WinGEMS toolbar is available in MS Excel 95 and Excel 97 as an add-in, allowing the user to run their WinGEMS simulation from Excel. New Derived Components are available to the user NaK sorption is now calculated taking into account the interaction between the two ions when both are present. Optional comma separator (1,529,000) is available to the user for values displayed in dynamic text. New flow unit class, Solids Mass has been added to the previously existing flow unit classes, which included total mass, total volume, liquor mass and liquor volume. In past releases, pulp mass was a derived value, and therefore was fixed and unavailable for user-definition. In WinGEMS 4.5, the user can choose to specify either liquor or pulp and then derive the other value.

9 Long file names are supported in WinGEMS 4.5, allowing the user to more easily identify files. Calculation Order Optimization Calculation order can now be automatically optimized to minimize convergence time and problems. WinGEMS Toolkit a set of general functions to query and manipulate WinGEMS externally, that may be called from other applications. WinGEMS 4.5 is a 32-bit application that runs in Windows 95, 98 and NT. At the time of this writing Windows 2000 is being beta tested. WinGEMS 4.5 executes in the current beta version of Windows In addition, WinGEMS 4.5 is Y2K compliant. WinGEMS 4.5 comes with the full compliment of process blocks which allows any part of the steady state pulp and paper process to be modeled. This includes the digesters, fiber lines, bleach plants, evaporators and concentrators, recausticizing and recovery, the power island, paper machines (both wet and dry end), TMP processes, water treatment, effluent treatment, coaters and more. Dynamics can be added for a modest upgrade fee. WinGEMS dynamic simulations are built from steady state simulations. Therefore the user does not have to start over to create a dynamic simulation.. 2. Discussion of applications WinGEMS 4.5 is owned by four major groups, pulp and paper companies both at the corporate and mill level, suppliers of pulp and paper equipment and products, engineering design and consulting companies, and educational and research institutions. Each group has a somewhat different focus. Mill level personnel are using the tool to solve operational problems, perform preliminary design analysis, quantify operational costs (both off and on-line) and identify business opportunities. Suppliers use the tool to quantify the impact of their equipment or product on mill operation. Engineering

10 companies use WinGEMS 4.5 for detailed design calculations as well as the same tasks as mill level personnel may perform. Finally educational and research institutions use the tool to educate students and perform fundamental research for the industry. Some use the tool as is and others incorporate custom models developed by the researcher and incorporated into the WinGEMS 4.5 interface with standard tools available from Pacific Simulation. Time commitment varies depending on the size and level of detail required for a project. For example, a simple screen room balance looking at just fiber and water can be done in less than an hour. If however, the user wanted to answer the question of what would be the incremental cost of energy for added coater drying capacity, a full mill simulation and financial model would be required to accurately determine the true cost. In either case the simulation time has been reduced dramatically because of the ease-of-use of the simulation tool. The parallel to the spreadsheet can be drawn. Many people are very proficient with the spreadsheet tool and can generate results very quickly. Other infrequent users of spreadsheets may not be as proficient as the power user, but they can still generate reasonable results in lesser time than would have been required with previous generation tools. Full mill simulations from fiber line through paper machine including recausticizing and recovery have been generated by new users in a two day beginner training class. Again, each simulation effort is dependent on the process issue at hand. These simulations were adequate to perform a preliminary fiber, water and chemical balance given adequate process data. However more detail would be required (and therefore more time) if the question of a detailed water balance were to be addressed. The main time consumer is not the generation of the simulation, but the collection and validation of process data. Some general project descriptions and approximate time requirements are listed below. Again, the major component of the time required is data gathering and process validation. Specialty paper machine simulation looking for greater up time opportunities a mill created a dynamic simulation of their paper machine. The simulation was validated against operation and used to determine how long it took to get to steady operation after addition of dyes. This project took approximately 150 hours of simulation efforts and included a spreadsheet output for graphical display of results. M&D digester simulation the mill wanted to determine the effect of screening sawdust prior to cooking on final kappa variation leaving the digester. This project took approximately 50 hours of simulation effort and included a final report. Full mill financial model for strategic reconfiguration a mill complex (groundwood mill, sulfite mill, recovery and 8 paper machines) was simulated at a very detailed level.

11 The simulation was interfaced to a financial model and the model was used to look at operational opportunities. Capital projects were evaluated individually and as groups of synergistic projects. The result from the evaluation was a several hundred million dollar capital plan. This project took nearly a year to complete and several thousand man-hours on the simulation and financial models. 3. Method of model preparation Construction of simulation model starts with a good understanding of the process. WinGEMS is a tool created by process engineers to solve process problems. It is just a tool and does not substitute for an adequate understanding of the process. The most common starting point is with P&I diagrams. From this basis the user selects process blocks from dropdown lists. Laying this block down is done with a click of the mouse. Other process blocks are laid down in a similar fashion. Streams are used to connect the process blocks by initially clicking with the mouse at the starting point of the stream and holding the mouse button down while dragging the mouse to the termination point of the stream. Stream values for input streams and initial block parameters are entered through dialog boxes that are accessed by double clicking on the appropriate stream or block object. Often previous projects generated by the user or examples supplied with WinGEMS are used as starting points or imported to new projects. The user can cut and paste these imported projects and compound blocks with standard Microsoft mouse and key conventions (Ctrl C for copy, Ctrl X for delete, etc.). Once constructed (and often during construction) the user can run the model by selecting the appropriate menu item or using radio buttons on the toolbar. Other features such as dynamic text, stream text tags, etc. enable the user to further annotate their project as the final output to be printed or plotted. The user can also output a complete listing of all blocks and streams to an output file that contains only user specified blocks or streams, or export the results to spreadsheets via Dynamic Data Exchange (DDE). 4. Simulation solver method WinGEMS 4.5 uses direct substitution as its calculation method and has built in algorithms to optimize the calculation order. WinGEMS allows the user to select calculation order, although by default it determines the calculation order automatically. Execution speed has improved with every release of WinGEMS. 5. Physical properties database Included with WinGEMS 4.5 are steam and water physical properties along with psychometric physical properties for air. WinGEMS 4.5 also contains physical property routines that describe boiling point rise, wood solids heat of formation, bomb heating value, and sorption. The user has the ability to override stream density and can input sorption coefficients if the defaults are not adequate for the situation or simulation requirements. 6. List of blocks

12 The standard block set and the dynamic block set are listed and described in response to question one above. In addition there are a set of detailed digester blocks and an oxygen delignification block available for an added fee. The digester blocks describe the delignification of wood in detail. They can be used alone or in conjunction with other WinGEMS blocks to describe the pulping reaction including kappa distribution, residual alkali, etc. Continuous and batch digesters can be modeled. The oxygen delignification block does predictive oxygen delignification modeling. A listing and description of the standard block set is contained in response to question 1 above. In addition to the standard block set there are detailed digester blocks that describe in detail the delignification of wood. These blocks can be used alone or in conjunction with other WinGEMS blocks to describe the pulping reaction including kappa distribution, residual alkali, etc. With the block continuous and batch digesters can all be modeled. 7. Results output options WinGEMS 4.5 has the ability to print or plot the project flowsheet with dynamic text and stream tags that represent all stream values (see section 1 and 3). In this way a properly configured simulation is a self-contained document for simulation inputs and outputs. Optionally the user can select an output or listing report. The output report lists the results of a simulation for user specified blocks and streams. The listing report contains all the final results for all blocks and stream in the simulation. WinGEMS 4.5 has the ability to export data via DDE from one WinGEMS project to another, to data files, to Access databases, and to Excel spreadsheets. The WinGEMS Toolkit has functions which programs such as Visual Basic and VBA can use to read and write data from WinGEMS. WinGEMS 4.5 also supports metafiles for output. This allows the user to copy all or part of a project and paste it into word processors, spreadsheets, desktop publishers, etc. 8. Advanced simulation features WinGEMS 4.5 contains a scripting language that enables advanced communication to spreadsheet programs such as Excel. One of the examples supplied with the software illustrates several alternatives run automatically with the results from each case going to

13 Excel and the financial results of the alternatives displayed graphically in Excel. WinGEMS 4.5 also has dynamic capability as described in Section one and two. WinGEMS has detailed predictive digester delignification blocks and an oxygen delignification block as described in Section six. WinGEMS 4.5 can also track descriptively user defined components including VOC and trace materials. Predictive VOC simulation is available from Pacific Simulation as part of full mill analysis. The WinGEMS Toolkit was recently added. It contains functions which can be called from programs such as Visual Basic, C, or C++ to manipulate WinGEMS and transfer data to and from WinGEMS. The primary use for the Toolkit has been to allow WinGEMS to be accessed by VBA macros from an Excel spreadsheet. These give access to the power of Visual Basic programming and Excel spreadsheets that may be needed for advanced simulation projects. 9. Special features that make WinGEMS easy to use Please see Sections 1 and 2 that describe WinGEMS 4.5 ease-of-use. WinGEMS also contains extensive on-line help that not only describes the interface but also each process block. Included are WinGEMS projects that have a working example of every option of every block. In addition, there are may process examples on disk and documented in the manual that describe full mill simulation, TMP simulation, pulp drying, bleach plants, detailed evaporators, detailed concentrators, paper machines both wet and dry end, peroxide bleaching of mechanical pulps, fiber lines, gas turbines and others. These provide an excellent basis for the new user to begin a simulation. The WinGEMS CD also contains 29 demo videos, complete with narration, each demonstrating specific functionality and techniques in WinGEMS. The intuitive graphical interface that adheres to Windows standard menu conventions, functionality and control keys provide the new user with a comfortable frame of reference from which to start his or her simulation efforts. WinGEMS has several debugging features that help the new user. While configuring the simulation, improperly connected streams turn red indicating to the user that something is amiss. If a block is improperly configured, either due to block parameter specification or stream connectivity then a red warning appears on the block. The user can click on the block and problems tab and there

14 will be a message indicating the error. In addition, during run time if an error occurs with a block an error indication will appear on the block. Again, the user can query the block to find out what the problem is. Even with the excellent documentation, training classes are very helpful to the new user. Each new copy of WinGEMS 4.5 comes with a voucher for a free two day WinGEMS training class. Pacific Simulation teaches dozens of training classes each year, in a variety of locations To keep the training personal and specific, class size is limited to 10 students. 10. Connectivity options WinGEMS 4.5 has DDE capability to allow input and output communication with other Windows programs such as Excel and Visual Basic. WinGEMS 4.5 runs on any Microsoft 32-bit operating systems (Windows 95, NT, 98). Any hardware that will run these operating systems will run WinGEMS 4.5. WinGEMS can communicate via DDE and Excel to mill information systems and DCS equipment. WinGEMS can also communicate to PI via the PI API and to CIM/21 via Desktop ODBC. 11. Simulator and model customization The WinGEMS 4.5 project file can be customized by the user. The icons supplied with the software are scaleable or the user can create their own icons. Text can be added with the font and color of choice, and streams can have the color of choice. The process blocks cover all areas of the pulp and paper process and are tunable through block parameters. However, if the user needs more functionality than are supplied by the process blocks he or she can create the model in Excel and call it from within WinGEMS using the scripting language. The WinGEMS Toolkit as described in Section eight allows the user to customize the WinGEMS project using Visual Basic, VBA or similar programs. There is also a WinGEMS Block Development Kit (BDK) available which allows the user to configure their own block from source code, compile it and link it in with the standard WinGEMS block set. The custom block then appears in menus as any other

15 standard WinGEMS block would. Source code for the process blocks is available for an additional fee. 12. Parameter and model limitations Limitations for some of the key components of WinGEMS 4.5 are as follows: Compound block parameters 250 Block parameters 40 Streams connected to any block 50 Stream components in a project s stream structure 150 Number of process blocks or streams in a diagram 32,000 With the use of compound blocks the only limit on the number of blocks that can exist in a simulation is the amount of computer memory available. 13. Hardware requirements Any hardware that will run a Windows 32-bit operating system will run WinGEMS 4.5. As with most current software the performance is improved with faster hardware. To use the demonstration videos included on CD, a sound card is necessary.