Optimal Analysis For A Steam And Power Cogeneration Plant By Burning Gas In A Space Heating Season

As an international metropolis, Tianjin, mainly use coal as fuel in the thermal power plants, and its energy consumption is large, but with a low efficiency in utilization. With the rapid development of Tianjin city economic construction for improving people's living standards, and the national energy-saving and emission reduction policies getting more strict in implementation, the distrcit heating projects are in a rapid growth, but within a rule that all of these should be environmental friendly and high efficient. The cogeneration plant of power and heat by burning natural gas is relatively clean, high efficient, low emission, and in consistent with the world appeal of low carbon economy. Tianjin, a northeast city of China, needs both heating and eletric power in a winter season. Therefore the cogeneration plant should play an important role in improving the local power supply structure, reducing the peak load capacity of power network, environmental protection and sustainable development in Tianjin.The research on gas- steam combined cycle cogeneration unit started lately in China, and in many aspects, such as the algorithm in design, running characteristics are not yet fully mastered. In addition, the production rate of China's natural gas is low, and the cost of gas burning power generation plant is higher compared with traditional ones. All these unfavorable factors make the Thermal Power Company Limited proposed the gas steam combined cycle unit as a research object. On the basis of thermodynamic analysis, the heat balance diagram and the unit power curve to calculate the parameters of heating season of electric load and consumption, and in various conditions, base heat loads etc are shown. For a heating season "two on one" mode is set in operation, The natural gas consumption rate are compared for the back pressure conditions and extraction condensing conditions. It is shown that the thermodynamic analysis in the heating seasonal mode is necessary in order to optimize the unit operation mode, to ensure the reliability in using natural gas, the highest heating efficiency of power plants.Through the calculation and analysis, the natural gas consumption curve, economic operation mode for a power plant in a winter heating season was proposed for the unit "one" and "the two one" mode of operation pressure and condensate pumping conditions, reasonable scheduling of gas group, has been achieved as expected.