Research On Calculation Model And Load Optiaml Dispatching Algorithm In Cogeneration Units

Combined heat and power generation (CHP) can improve the efficiency of energy utilization and has good economic returns, which is in line with the principle of using energy according to its quality. Replacing the small industrial boilers with thermal power plant high-capacity boilers will enhance boilers efficiency and dust removal efficiency, reduce the emissions of SOx and NOx as well as improve the quality of the environment and bring in good social benefits.Because the energy cost characteristics and load dispatch for cogeration units are more complicated than conventional power plants, so this thesis is forcus on the energy cost characteristics and load dispatch for cogeration units to improve its operating economy.The main research contents and achievements of the thesis are listed as follows:(1) General calculation model for cogeraiton units based on cycling function methodCogernation thermal systems are divided into six modulars:the module for thermodynamic system structural description, the module for thermal system parameter description, the module for thermodynamic properties calculation, the module for the heating unit water coefficient calculation, the module for individual characteristic coefficient calculation, the module for integrated characteristic coefficient calculation. This generic model is applied to get power characteristic equation of single extraction units and double extraction units.(2) Research on the expand for the the principles of equal incremental distributionFor the case of linear equations consumption characteristics, combined with the optimization problem the optimal solution of such geometric interpretation of the principle of equal incremental load distribution to expand, it made little slight increase distribution.(3) Research on heat and power load dispatch for single extraction unitsA method based on characteristic coefficients for single extraction units was proposed.The relationship of inlet stream characteristic coefficients and overall heat duty, steam consume coefficients and overall power duty were analyzed, according to load dispatch results which does not meet the constraints, a adjustment program was proposed.Compared the results based on linear programming and based on characteristic coefficient shows that the two results are consisent and the method based on characteristic coefficient cost less time to get results.(4) Research on heat and power load dispatch for double extractions unitsA method based on characteristic coefficients for double extractions units was proposed.The relationship of industrial inlet stream characteristic coefficients and overall industrial heat duty, heating inlet steam stream characteristic coefficients and overall heating heat duty, consume coefficients and overall power duty were analyzed. According to load dispatch results which does not meet the constraints, a adjustment program was proposed.Compared the results based on linear programming and based on characteristic coefficient shows that,almost conditions the two results are consisent, and for the remaining conditions, the two result shows little deviation in 0.027%, and this is a acceptable result.And the method based on characteristic coefficient does little calculation and easy to operate.