Research On Intelligent Control System Of Waste Heat Recovery Of Thermal Power Plant

In the thermal power plant, the exhaust gas, who is from the high-temperatureand high-pressure steam after acting, is discharged into condenser to exchange heatwith circulating cooling water. The circulating cooling water, after exchangeing heat,will heat up to30~45℃and belongs to low-grade heat source, which is diffcult torecycle. So the circulating cooling water is directly fed into cooling tower to cool.Because of the good quality and stable flow, the circulating cooling water containshuge heat, which would result in energy waste and environmental pollution if norecycled well. According to the report, the heat, is away by the circulating coolingwater, accounts for about60%of the total energy consumption of the thermal powerplant. So the energy-saving effect of the power plant depends largely on the way torecycle this part of heat.The Cogeneration of Heat and Power (CHP) system replaces the decentralizedheat-supply of small and medium-sized boiler, not only saving energy but alsoimproveing heating efficiency. However, due to the heat loss of high temperaturesteam in the course of transmission and the pipe-laying costs, the heating radius of theCHP system is limited. At the same time, due to the presence of large temperaturedifference, the CHP system exists the serious and irreversible heat loss. Each coin hastwo sides, the huge temperature difference provides favorable conditions for theapplication of heat pump technology in the CHP system. In the CHP system, using theheat pump technology to recyle the waste heat of circulating water for central heating,makes up for own shortcomings of the CHP system also gives full play to theadvantages of heat pump technology. Finally the advanced CHP system betterrecycles the waste heat of circulating water, obtaining favourable economic benefit. Inthis paper, the combined absorption heat pump units and the compression heat pumpunits apply in the waste heat recycling system of the circulating water. Therefore, thispaper puts forward the comprehensive scheme to recycle the power plant’s circulatingwater heat, including three circulatory systems: the compression heat pump unitpreheating boiler mae-up water system, the combined absorption heat pump unitsproviding central heating system and domestic hot water system, which not only runat the same time but also function independently. The comprehensive scheme makesuse of the waste heat of circulating water in maximum limit and improves the the comprehensive utilization rate of energy. The climate compensation device is installedin heating systems, seting time-sharing partition control according to needs of users,which makes the heating systems could adjusted the hot water temperature in realtime according to dynamic change of the outdoor climate, not only keeping stable andcomfortable of the room temperature but also reducing energy consumption in warmclimate, obtaining good comprehensive benefits.