Influence of Fuel Cost on the Operation of a Gas Turbine-Waste Heat Boiler Cogeneration Plant

The influence of fuel cost on the operation is investigated for a gas turbine-waste heat boiler cogeneration plant by an optimal operational planning method. A planning method is first presented by which the operational policy of each piece of constituent equipment is determined so as to minimize the operational cost. Then, a case study is performed for a cogeneration plant used for district heating and cooling. Through the study, it is made clear how the optimal operational policy and the economic or energy conservative properties are influenced by the costs of purchased electric power and natural gas. It is also shown that the optimal operational policy is superior in economy as compared with other conventional ones.