Development Of Cogeneration Load Distribution Optimize System In Papermaking Mill

The Cooling, Heating, and Power (CHP) systems have been widely recognized as a keyalternative for thermal and electric energy generation because of the outstanding energyefficiency, reduced environmental emissions, and relative independence from centralizedpower grids.Nowadays, most power plant of paper mill in China is coal-fired power-heat systemwhich supply power for paper machine and other instruments and mainly supply steam topaper machine dry section. And many paper mills have self governed power plant, most ofthem have more than one turbines and one boilers. For this kind of paper mill power plant,different turbine unit load and boiler unit load will lead to different coal consumption whenproducing the same power and steam. The turbine unit loads and the boiler unit load werevery important because there is an optimal load distribution which will result in the minimumcost.Optimal operation of a CHP system is not easy to achieve because the demandfluctuation of steam in paper mill is big such as sheet breaking in paper machine which willlead to sharply decrease of steam usage. In practice, CHP systems are often operatedaccording to the pressure of main steam manually so that the extraction drop lags the steamconsumption. In this paper, the optimal distribution of heat and power is discussed, aim atpracticality. Considering the characteristic of combined heat and power units, themathematical model of the turbine is established, where the total consumption of steam ischosen to be the optimization objective contrasting and the constrains are settled afterlinearizing the relations between heat and power.To get the minimum cost, an optimal energy dispatch algorithm has been developed for aCHP system to fulfill the distribution of heat and power of turbine. The LP model isformulated based on real data and LP-Solve was used to solve the linear equation. At last theoptimize platform was developed to fulfill loads optimal distribution. Finally the results fromthe case study illustrate the potential economical gain resulting from optimizing the operationof the CHP system. It proved the turbine load distribution optimization is an importantmethod for paper mill power plant economically operation and energy saving, it can reducethe energy consumption and exhaust emission and profile and environment.