Mine ventilation analysis and simulation have been run on computers since the mid 1960s. One of the earliest programs was published by Pennsylvania State University Mining Department in Mining Engineering in 1965 (or thereabouts). The program used a Hardy-Cross network balancing technique which was originally developed for analyzing water flow networks. The Penn State program included the ability to enter fan curves and put regulators in the network.

Other ventilation analysis software was developed by the U.S. Bureau of Mines and at Michigan Tech. The MFIRE program developed at Michigan Tech in the 1970s included the ability to analyze a ventilation network with a simulated fire situation. Thermodynamic calculations were added to the network analysis scheme to provide more realistic air flow analysis which considered air temperature as well as volumes.

Ventilation analysis systems have also been developed by other government organizations such as CANMET in Canada, Ineris(Cerchar) in France, COMRO in South Africa, and CSIRO in Australia. The early programs were developed in the DOS environment. It is still possible to find these programs (many of which are free code), but some digging is required to locate copies.

The ventilation analysis systems listed below are provided commercially by consultants, sometimes in cooperation with government agencies. These programs are Windows programs and include graphics as well as the network calculations.

The CLIMSIM program is a highly specialized, interactive package for predicting the variation in psychrometric and thermodynamic properties of air as it travels along shafts, slopes, or underground airways. The program delineates the psychrometric and thermodynamic conditions of the air at user defined increments using the airway characteristics, rock thermal parameters, heat sources, and air inlet conditions. Capabilities of the program include:

• Allows networks to be entered to simulate multiple airways in parallel or series.
• Utilizes any WINDOWS printer, plotter and digitizer drivers.
• Incorporates five independent WINDOWS views.
• Incorporates latest theory on heat transfer and heat stress indices.
• Spreadsheet type data input and output for viewing and printing reports.
• Full cut, copy, paste functions within the CLIMSIM program, and to other WINDOWS applications.
• Full-color screen graphics for viewing and printing/plotting.
• Complete Zoom and Pan capabilities.
• Full technical and engineering support.
• Compatible with Windows Version 3.1, Windows 95 and Windows NT.
• Complete User’s Manual and Help Menu.
• Demonstration copies of the program are available free of charge.

The software is written in C++, Visual C++ and FORTRAN. It runs on PC or Laptop with Windows 3.1/95/NT. Price: $950 new, $650 upgrade from DOS, $300 for universities

For more information contact Keith G. Wallace, Jr., Ian J. Duckworth, or Brian S. Prosser, Mine Ventilation Services, Inc. 4946 East Yale Avenue, Suite 103, Fresno, California, 93727. Telephone: (559) 452-0182 Fax: (559) 452-0184. Web: www.mvsengineering.com

Input of normal ventilation survey data, such as airway resistance, pressure drop and air quantity, allows calculation of the network by the Hardy Cross method. This may be used to generate tabulated reports, graphs of fan curves and fan operating points., network distribution diagrams, showing pressure drop, resistance and cost per year and plans of airflow distribution.

Up to 50 regulators and up to 10 surface or underground fans can be specified. Airflow across goafed areas may be represented as leakage paths. Natural ventilation pressure can be considered. Network diagrams may be superimposed on mine plans generated by MINDRAFT.

For more information contact Australian Coal Industry Research Laboratories, Ltd. 14-30 Delhi Road, P.O. Box 83 North Ryde, NSW 2113 AUSTRALIA. Telephone: (61) 07 3282 2011. FAX: (61)07 3816 1107. Email: info@acirl.com.au http://www.acirl.com.au/

This ventilation simulator was developed in 1986 and consists of the analytical calculation systems, as well as RDBMS, the 2D/3D graphic CAD system for deformed network skeleton and air-conditioning design system.

The "Skyline Nodal Pressure Method", used in MIVENA, has been successfully applied to the network flow analysis scheme. The main functions of the MIVENA program are as follows:

1) The installed strong analytical system for airflow rate and climate.

2) The input and output data forms designed in consistence with Windows applications, such as work-sheet data, text, HPGLTM, Image pictures registered to the node/airway.

3) The RDBMS designed to have some convenient functions used to delete or add nodes and airways automatically by the original functions express the connections of nodes.

4) The RDBMS also has advantages to set up a data-base to describe the mine layout and solve network airflows for ventilation planning and design.

5) The computer aided air-conditioning(cooling and heating) system developed to estimate airflow climate by using a psychrometric system.

6) The psychrometric chart presented on basis of the accurate equations for air conditions applicable to a very deep underground mine. The ranges of pressure, temperature and humidity may be specified by users.

The Computer Aided Air-Conditioning System: AIRPLOT(Psychrometric Chart) is included in the software to estimate airflow climate by using a displayed psychrometric chart based on the accurate equations for air conditions applicable to a very deep underground mine. The psychrometric chart is available for ranges of pressure, whilst temperature and humidity may be specified by users.

The programs were originally written in MS Visual BASIC Ver. 5(TM) and Visual C++ Ver. 2(TM) (Open-GL script was partly used for the 3D graphic). MIVENA and AIRPLOT run in Windows 95a/95b/98/NT3.51(SP5)/NT4(SP3). A free download of MIVENA(ver6.2b) is available from the Web site: http://www.mine.akita-u.ac.jp/mivena/Index-e.html

For more information contact Akita University, Department of Earth Science and Technology, Faculty of Engineering and Resource Science, Akita 010-0852. JAPAN. E-mail: sasaki@uws47.mine.akita-u.ac.jp

Tel: +81-188-89-2395, Fax: +81-188-37-0401

The VnetPC program is a Windows based program designed to assist personnel in planning underground ventilation layouts. The program provides detailed listings and graphical representations from data that describes the geometry of the mine network, airway resistance or dimensions, and the location and characteristic curves of fans. Output includes:

• Branch Airflows.
• Frictional Pressure Drops.
• Airway Resistance.
• Air Power Losses in Airways.
• Ventilation Cost of Each Airway.
• Fan Operating Points (Pressures and Airflows).
• Duties of Required Regulators and Booster Fans.
• Gas Flows and Concentrations in Branches.

VnetPC 2000 (for Windows) is a completely new program entirely programmed in the 32-bit format. The computation routine behind the graphical interface is based on the same proven method as earlier DOS versions. The following features are a few of the many that have been added:

• The Schematic View is fully interactive from the mouse, allowing the user to develop and manipulate networks entirely from this view.
• The network may be established and viewed in 3-D World coordinates. Views include Plan, Cross-Section, Long-Section and 3D.
• DXF import allows networks to be developed as Lines, Polylines, and Text, and to be imported into VnetPC as levels/groups of data, or as an entire mine.
• The ability to color-code branches for type (intake, return, etc.) or range (airflows, pressures, etc.).
• The option of specifying surface branches so that "dummy" zero-resistance connections are no longer required.
• The option of automatically computing fan curves for fans added in parallel or series arrangements (multiple fan tool).
• Automatic branch length calculation tool. This feature allows the user to determine branch length based upon mine coordinates.
• Network size limits are set at 5,000 branches and 500 fans. The iteration limit is set at 1000.
• Regulator orifice sizing tool for Fixed Quantity data.
• Report feature, to allow Printed Output to be generated that incorporates data from the 9 separate views.
• VnetPC can simulate existing ventilation networks such that fan operating points, airflow quantities, and frictional pressure drops approximate those of the actual system.

The minimum hardware requirements include: IBM Compatible Computer running Windows 95, 98 or NT; Pentium class processor or higher; 16 MB RAM Memory; 10 MB Hard Disk Space. The price is $1000.

For more information contact Keith G. Wallace, Jr., Ian J. Duckworth, or Brian S. Prosser, Mine Ventilation Services, Inc. 4946 East Yale Avenue, Suite 103, Fresno, California, 93727. Telephone: (559) 452-0182 Fax: (559) 452-0184. Web: www.mvsengineering.com

Ventsim is an underground mine ventilation simulation package designed to simulate airflows (and many other types of ventilation data) from a network of airways. The software integrates Windows graphical design with 3D graphics similar to high end CAD packages.

The program uses a fully graphical mouse driven interface in Windows. Features of Ventsim include the following:

• - Up to 20,000 individual airways can be entered into a network
• - Up to 1000 different types of fans, complete with efficiencies can be modeled within the network.
• - Up to 1000 different levels of airways can be used.
• - Networks can easily be created true to scale in three dimensions, simply by drawing airways with the click of the mouse.
• - 3D rotation allows the modeled network to be rotated in real time to assist in viewing and creating.
• - Contaminant simulation allows simulations of smoke, fumes or other contaminants throughout a mine.
• - Importing and Exporting ASCII or DXF data from spreadsheets or other CAD or Mine Planning packages.
• - Load modeling on regulators and bulkheads.
• - Pressure modeling of fans and fixed airflows.

These features provide the user with the tools to:

• Simulate and provide a record of flows in an existing mine.
• Perform 'what if' simulations for planned new development.
• Help in short term and long term planning of ventilation requirements.
• Assist in selection of types and sizes of fans for mine ventilation.
• Help in choosing development fans and vent bag sizes.
• Assist in financial analysis of ventilation options.
• Simulate paths and concentrations of smoke, dust, or gas for planning or emergency situations

The software runs on IBM PC with Microsoft 95/98/NT/2000. The price is: AUD$1,800 US$1150. Special Academic/Educational Prices exist for Ventsim. For further information email to ventsim@ventsim.com

VUMA is a windows-based software package for simulating atmospheric and environmental conditions in underground mines. Joint developers, CSIR Miningtek and Bluhm Burton Engineering of South Africa, are international leaders in this field. This product is based on current research and development and uses state-of-art procedures and technology. All algorithms have been verified in recent work and over a development period of some two decades.

VUMA allows a mine network to be built up by linking numerous component elements, each with specific aerodynamic, thermodynamic and contaminant characteristics. The basic component elements [branches] comprise: shafts, shaft stations, tunnels, development headings, stopes, fans, control manager elements [which include air coolers and regulators].

The program simulates ventilation flows, temperatures, humidity and dust and gas concentrations throughout any mine network. It can be applied to a full variety of underground mining methods for narrow-reefs, massive ore-bodies and colliery layouts with different levels of mechanization.

Two- and 3-dimensional graphic enhancements facilitate creating, editing and analysis of mine ventilation networks. The software can be used as a planning tool and as a means of verifying environmental and energy parameters in operational mines. The concept of real-time VUMA network analysis driven by on-line monitors has great benefits for energy consumption control and reduced operating costs.

Heat flows, dust and gas loads are calculated and can be used to analyze cooling strategies, contaminant dilution and ventilation tactics. These include overall energy requirements and fans, air coolers and scrubber/filter needs. VUMA can be used for effective energy management and the creation of safe and healthy conditions in mines.

Verified engineering principles are used to accurately calculate and quantify the relevant parameters. However, in mining environments, there are some inputs that are difficult to quantify and rating categories have been developed for these inputs. For example, categories are provided for: rock surface wetness, condition of pipe insulation, diesel work cycles, moisture ratings of heat sources, in-stope water use and others.

A ‘steady-state’ flow simulator calculates aerodynamic, thermodynamic and contaminant dynamic [and tracking] properties. In underground environments, ‘transient-state’ simulations of these parameters are only important in particular circumstances [for example power failures]. ‘Transient-state’ simulators form another class of software and are available as separate stand-alone products.

Graphics facilities include 2-dimensional interface with panning and zooming used for simple generation and management of network data and 3-dimensional graphics with panning, zooming and rotating features for ease of visualizing and viewing the networks.

Vuma can be bought on license or direct terms. Licensed purchases may be renewed on a yearly basis while direct sales are not time limited. License purchases include a user group membership as well as any further updates. The pricing structure for international sales (outside South Africa) is as follows: Direct sale, $3400; Annual License $1800; Universities $3000 for multiple copies.