Equipment Selection And Economic Analysis Of Waste Heat Depth Utilization System In Utility Boiler

Thermal power plant is based on the Rankine cycle to realize the conversion of heat into power to gain energy. At the same time of access to energy, there is a big heat loss, in which the boiler flue gas heat loss is the main source. The use of corrosion-resistant material in thermal power plant created a new opportunity for the further reduce of boiler flue gas within the scope of about130～150℃in the active power station.The waste heat utilization technology in recent years has made a great progress, and the forms of the waste heat utilization system are various. But most of them remain in the theoretical analysis, The majority of the form of the practical application is relatively simple. In this paper, the energy-saving principles of the European energy efficient waste heat utilization system is deeply analyzed with the method of thermodynamic analysis principle. However, due to the differences of the coal and boilers, direct introduction of foreign equipment is not necessarily able to achieve a good energy saving effect, or even counterproductive. Therefore, this paper made a selection of thermodynamic parameters and detailed calculation of the economizer effect based on the typical ultra-supercritical coal-fired unitsSecond The front air preheater is deeply analyzed and made a detailed analysis and calculation of front air preheater based on the fluid mechanics and heat transfer theory. In further heat exchanger performance evaluation, the grey theory of hierarchy analysis was introduced, using scientific performance evaluation method to comprehensively evaluate the heat exchanger device, finaly concluded the suitable forms of air preheater for large coal-fired power plant boiler heat. So this paper provides a scientific and feasible method of the heat exchanger for power plant equipment selectionAt last, comprehensive economic benefits is the most direct factors for the power plant whethter to do reengineering. Only on the basis of thermodynamic analysis to determine the economic benefits of power plant renovation is not enough. So in this paper, by using the theory of technical economics, Established a complete set of initial investment analysis process and the economic evaluation method of waste heat utilization system.The increased power consumption of the plant reconstruction system and net coal saving benefits is especially considered.The research achievements in this paper will be beneficial for further design and optimization of the flue gas waste heat utilization in large-scale coal-fired power plants.