International Scientific Journal


Tri-generation systems are used to simultaneously produce electrical, heating, and cooling energy. These systems are usually more efficient than conventional systems for separate production and have smaller distribution losses since they are often located closer to the consumer. For achievement of the best technical and/or financial results, tri-generation plants have to be properly, i. e. optimally designed and operated. Operational optimization is used for short term production planning, control of tri-generation systems operation and as a part of design level optimization. In this paper an approach to operational optimization of tri-generation plants with reciprocating engines is presented with the following mathematical model. It is also explained how this algorithm might be embedded in some larger optimization procedure. In this approach, the importance of the part load performance of different units of the tri-generation systems is emphasized, especially of co-generation unit, i. e. engine generator set and thus it relies on manufacturers' data and is characterized with relatively high level of details examined. Mathematical model is based on the equipment performance based constraints and demand satisfaction based constraints with the possibility to add more equations if appropriate. Objective function for optimization is benefit-cost function. Optimal operation regimes for typical days for each month are obtained and analyzed. Impact of electrical energy price on pay-back period and primary energy saving is analyzed. Primary energy savings are determined and compared to maximal value that could be obtained.
PAPER REVISED: 2009-12-22
PAPER ACCEPTED: 2010-01-20
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THERMAL SCIENCE YEAR 2010, VOLUME 14, ISSUE Issue 2, PAGES [541 - 553]
  1. EDUCOGEN - The European Educational Tool on Cogeneration, The European Association for the Promotion of Cogeneration, 2001
  2. Dotzauer, E., Algorithms for Short-Term Production Planning of Cogeneration Plants, Licentiate thesis, Linköping University, Linköping, Sweden, 1997
  3. Dotzauer, E., An Introduction to Short-Term Scheduling of Power and Cogeneration Systems, Research Report MdH/IMa 2001-1, Mälardalen University, Västerås, Sweden, 2001
  4. Kalina, J., Skorek, J., Cost Effective Operation of Boiler Plant with Embedded Gas Engine Cogeneration Module, Proceedings (Eds. C. A. Frangopoulos, C. D. Rakopoulos, G. Tsatsaronis), 19th International Conference on Efficiency, Cost, Optimization, Simulation and Environmental Impact of Energy Systems ECOS 2006, Aghia Pelagia, Crete, Greece, 2006, Vol. 1-3, pp. 1201-1209
  5. Cho, H., et al., Cost-Optimized Real-Time Operation of CHP Systems, Energy and Buildings, 41 (2009), 4, pp. 445-451
  6. Lahdelma, R., Hakonen, H., An Efficient Linear Programming Algorithm for Combined Heat and Power Production, European Journal of Operational Research, 148 (2003), 1, pp. 141-151
  7. Rong, A., Hakonen, H., Lahdelma, R, An Efficient Linear Model and Optimization Algorithm for Nation-Wide Combined Heat and Power Production, TUCS Technical Report No. 531, University of Turku, Turku, Finland, 2003
  8. Rong, A., Lahdelma, R., An Efficient Model and Optimization Algorithm for tri-generation, TUCS Technical Report No. 598, University of Turku, Turku, Finland, 2004
  9. Rong, A., Lahdelma, R, Efficient Algorithms for Optimizing Combined Heat and Power Production under the Electricity Market, TUCS Technical Report No. 615, University of Turku, Turku, Finland, 2004
  10. Rong, A., Lahdelma, R., An Efficient Linear Programming Model and Optimization Algorithm for tri-generation, Applied Energy, 82 (2005), 1, pp. 40-63
  11. Chicco, G., Mancarella, P., Matrix Modeling of Small-Scale tri-generation Systems and Application to Operational Optimization, Energy, 34 (2009), 3, pp. 261-273
  12. Bojić, M., Stojanović, B., MILP Optimization of a CHP Energy System, Energy Conversion and Management, 39 (1998), 7, pp. 637-642
  13. Chicco, G., Mancarella, P., tri-generation Primary Energy Saving Evaluation for Energy Planning and Policy Development, Energy Policy, 35 (2007), 12, pp. 6132-6144
  14. Stojiljković, M. M., Stojiljković, M. M., Blagojević, B. D., Primary Energy Savings Potential in Optimized Small Scale Cogeneration Plants, Proceedings on CD, International Symposium Power Plants 2008, Vrnja~ka Banja, Serbia, 2008
  15. Osman, A. E., Ries, R., Optimization for Cogeneration Systems in Buildings Based on Life Cycle Assessment, Journal of Information Technology in Construction IT Con, 11 (2006), Special issue, pp. 269-284
  16. ***, DOE-2 Engineers Manual Version 2.1A, University of California, Berkley, Cal., USA, 1982
  17. ***, EnergyPlus Engineering Reference, 2009,
  19. Hudson, C. R., ORNL CHP Capacity Optimizer User's Manual, Oak Ridge National Laboratory, Oak Ridge, Tenn., USA, 2006
  20. ***, Guide to Cost Benefit Analysis of Investment Projects (Structural Fund-ERDF, Cohesion Fund and ISPA), Prepared for Evaluation Unit DG Regional Policy, European Commission, 2002
  21. ***, Directive 2004/8/EC of the European Parliament and of the Council of 11 February 2004 on the promotion of cogeneration based on a useful heat demand in the internal energy market and amending Directive 92/42/EEC, Official Journal of the European Union, L 52 (2004), pp. 50-60
  22. ***, Commission Decision of 21 December 2006, establishing harmonised efficiency reference values for separate production of electricity and heat in application of Directive 2004/8/EC of the European Parliament and of the Council, Official Journal of the European Union, L 32 (2007), pp. 183-188
  23. ***, 2008 HVAC Systems and Equipment Handbook (SI Edition), ASHRAE, GE, USA, 2008

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