The Software Development Of Energy Efficiency Prediction For Large Thermal Power Units

In the actual operation and production of power plants, some operationalparameters in thermodynamic system tend to fluctuate and deviate from the designedvalues because of some reasons. It will not impact on the security of the unit ifoperational parameters change in the permitted range, but the energy efficient ofthermodynamic system is bound to change and sometimes the change is very great.Therefore, it can be seen that the analysis about how to predict their influences onenergy efficiency has an important guiding significance for energy saving. The mainstudy contents and conclusions of this paper are as follows:(1) Based on the energy-efficiency analysis model which can apply tocalculate the economy of thermodynamic system that under the condition of randommultivariate disturbances. Write a program that can predict the amplitude ofvariation and the regularities of distribution for energy efficiency of thermodynamicsystem under random multivariate disturbances with MathCAD software. Thisprogram was proved to be correct by the calculation of a600MW thermal power unitand the comparison results with the traditional thermal equilibrium method.(2) Predicted the degree of every disturbance factor impact on energyefficiency (the rest disturbance factors are in the design value) for a600MW unit inTHA condition respectively and then drew the bar graphs according the calculationresults. Then analyzed and compared the impact on energy efficiency and thedistribution law of energy efficiency for thermodynamic system under the conditionof different dimensionless parameter perturbations with the help of bar graphs, therelative variation of energy efficiency was positive when the wide-area disturbancesincreased and the relative variation of energy efficiency was negative when thewide-area disturbances decreased. While the effects on energy efficiency wasopposite to wide-area disturbances when the disturbances were locality. Theinfluence degree of wide-area disturbances on the energy efficiency was two times orthree times more than the influence of local disturbances on the energy efficiencywhen the rate of wide-area disturbances change was the same as the rate of localdisturbances change.(3) Predicted the impact of multivariate disturbances on energy efficiency forthree power plants of different installed capacity. Then analyzed and compared thevariation of energy efficiency for thermal power plants of different installedcapacities in different conditions with the help of trend graphs. Under the same condition, the amount of energy efficiency change was positive when thedisturbances were positive and the amount of energy efficiency change was negativewhen the disturbances were negative. The absolute value of the amount of energyefficiency change was substantially linear increase when the rate of the absolutevalue of disturbances change was increase. In addition, the impact of thedisturbances on energy efficiency was not only related to the amount of disturbanceschange but also related to the condition of the units. The lower condition the unitworking on, the stronger the disturbances effect on energy efficiency, so it must bepay more attention to the impact of the disturbances on energy efficiency when theunits was in low condition.(4) We can calculate the degree of the impact on economic fast and accuratewith the help of this program when the units were under the condition ofmultivariate disturbances. So it provided a new tool for the quantitative analysis ofthe degree and the distribution law of energy efficiency for thermodynamic systemunder random multivariate disturbances.