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Student Projects
Video showing actual performance of Experiment
Contact Information
University: College Of Engineering, Pune.
Team Members: Anjali A. Patil,
Rohan A. Paranjpe,
Rajesh S. Kaje,
Prashik D. Khadse.
Faculty Advisor: Prof. P.R. Dhamangaonkar.
Email Address: anjali.patil89@gmail.com,
Project Information
Title: Design and Development of Virtual Experimental Set-up to Determine Efficiency of Boiler by Direct and Indirect Method
Description:
Virtual labs are a fusion of creative engineering and objective conceptualization techniques to yield an interactive experience. It is a set of teaching and learning tools designed to enhance a student's learning experience. Computer animation and visualization can help to illustrate complex physical phenomena easily. Furthermore, they give us additional insight into problems during classroom teaching as well as in the individual study process.
Products:
LabVIEW 8.6
The Challenge:
To develop experiment “determination of boiler efficiency”, it was mandatory to understand concepts of steam generation, boiler and its performance measurement methods and heat balance sheet. There are two methods for determination of boiler efficiency as follows:
- Direct method
- Indirect method
Directmethod includes the calculation of heat content in steam according to steam pressure and conditions. Calculation of efficiency by direct method takes theratio of energy obtained in the form of steam to the energy which is suppliedby fuel. The effect of changing fuel on the efficiency is considerable due tochange in calorific values. Various fuels used are Lignite, Anthracite, Bituminous, LDO and FO
Indirect method includes calculation of various heat losses from the boiler. Those areas follows:
- Loss due to dry flue gas (sensible heat)……………………..……..L1
- Loss due to hydrogen in fuel (H2)……………………………..…..L2
- Loss due to moisture in fuel (H2O)………………………………..L3
- Loss due to moisture in air (H2O)…………………………………L4
- Loss due to carbon monoxide (CO)……………………………....L5
- Loss due to surface radiation, convection and other unaccounted… L6
- Unburnt losses in fly ash (Carbon)………………………………...L7
- Unburnt losses in bottom ash (Carbon)……………………………L8
The formulae required for above loss calculations are obtained from BEE journal published for reference. Contents from Ultimate analysis of fuel as well as GCV are also used. Determination of humidity factor is done from boiler room temperature by considering it as dry bulb temperature.
The Solution:
Development of VI for calculation of boiler efficiency by direct method: Limiting conditions for input is decided. A subVI is made for capturing values from steam table to limit the number of input parameters. Values for hf, hfg, hg, Tsat are taken from this subVI. As selection of formulae according to steam condition is necessary, use of case structure is made. In addition to efficiency calculation, calculations for evaporation equivalent and evaporationratio are added.
Development of VI for calculation of boiler efficiency by indirect method: Since number of calculations involved in this method is more, use of multiple subVIs is done. Each loss is calculated by making an independent subVI. The outputs of allthese subVIs are wired together to calculate total heat loss and thusefficiency.
Integration of both methods within single VI: for comparison between results obtained from two methods of boiler efficiency calculation, it is essential to incorporate both these VIs together. This is done by the use of case structure. Toggle switch is provided for method selection which guided the case structure.
Property nodes are also used for sequential displaying of all parameters on front panel in desired order. Outputs are represented in observation table on front panel by using table. For obtaining this table in user accessible form, ‘function write spreadsheet file’ is used. All the data is converted from numeric form to fractional string and given to observation table.
To facilitate the performance and use of setup, instructions are also provided inprocedure window. User can access detailed instructions by open a separate VI on click of ‘Theory’ button. This is achieved by use of property nodes and invokes nodes. For continuous execution this process was achieved by use of while loop. The VI property was changed to run on start for execution of VI assoon as it is opened. This avoided the need of providing separate start buttonon front panel.
Figure: Experimental set-up of Boiler Experiment
Open VI named 'Boiler Experiment' from the attached zip file.
Great work !!!!
Hope you continue making such experiments and make learning efficient.
All the best 
