Optimization of CHPP with CCGT and steam turbine units modes for profit maximization on the wholesale electricity market

Relevance. Optimization of CHPP modes is the most urgent task to increase profits on the wholesale electricity market. Free market economy forces CHPP’s to optimize its operation to achieve additional profits on Balancing electricity market.

The purpose is to increase marginal income of CHPP at the Wholesale Electricity Market by modes optimization.

Methods. The method of CHPP simulation modelling and the method of CHPP heat balances calculation were used. The digital twin of the investigated power plant was created in CAE United Cycle. United Cycle also provides the ability to calculate heat and mass balances of the CHPP in stationary modes. Other calculations were carried out by Microsoft Excel.

Results. The paper presents the results of fuel costs reduction due to return network water heat flows redistribution between steam turbine and combined cycle gas turbine. This result was achieved by solving the system of balance equations of power units of the investigated CHPP. A profit increase on the market with constant output of electricity and heat was achieved. The functions of additional power generation and fuel costs have been investigated. The cash flow of revenue and expenses was analyzed. The local extremum of the maximum profit on the balancing market was determined.

Conclusions. In a result of heat loads redistribution between steam and combined-cycle gas turbines, a reduction of total fuel consumption up to 7% was achieved. This ensures profit growth up to 60.59 thou.rub./h. The investigation of the optimal amount of power increase at Balancing market leads to profit growth up to 14.62 and 128.22 thou.rub./h for steam and combined cycle gas turbine, respectively.

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