The Theory Research And Application Of Waste Heat Based On The Absorption Heat Pump In The Thermal Units

With the development of economy, the power plant generally faces the growing demand of heat, but power plant cooling water carries off a lot of heat at the same time, in order to improve utilization efficiency of energy and satisfy the demand of heat heating, the first kind of absorption heat pump is used to recover the waste heat of circulating cooling water in the paper. In the heating period, the heat pump heats the heating water to increase the heating capacity of the unit, and in the non heating period, the heat pump heats condensed water to improve the efficiency of the unit.To the coal-fired plant, the analysis of the distribution of energy is done, the result shows that the waste heat is mainly in the flue gas and the exhaust steam. According to different utilization projects of waste heat, the absorption heat pump and the compression heat pump are analyzed, the conclusion shows that the absorption heat pump is the best choice of recovery the waste heat of circulating cooling water. To the absorption heat pump, mathematic model of the parts are built, and the heat pump is designed according to a real power plant. In the heating period, in order to improve the capacity of the heat pump to extract the heat, the back pressure of unit is improved. To optimize the back pressure of unit, the maximum profit of unit is as the objective function, and the result shows, to indirect cooled unit, when the back pressure is 9Kpa, the profit is the largest, and is 5.4832 million Yuan; to direct air cooled unit, the profit is 7.7431 million Yuan when the back pressure is design pressure.In the non heating period, to a N200 unit, under different driving heat source and different condensed water, the economy is analyzed, the result shows that, when the same level steam drives the heat pump, more profits are gained with the high parameter of steam; when the high level steam drives the heat pump, using the sixth period of extraction steam drives the heat pump to heat the condensed water of no.2 low-pressure heater, and the profit is the best, the unit coal consumption reduces 0.25 g/(kw·h); when the flue gas drives the heat pump, the unit coal consumption reduces 0.63 g/(kw·h).