The Best Vacuum Research Combined Cycle Air Cooling System

In recent years, Composite air-cooling system has been Proposed because of thesame water-saving rate to the direct air-cooling system，and its back pressure issimilar to the water-cooling unit. It’s a good remission for the direct air-coolingtechnology which has the problem of high coal consumption and poor ability to adaptto the environment, and the indirect air-cooling system has the problem of “ofur moreand one diff"iculty. It has important theoretical significance and great practical valueon air-cooling technology. The research on composite air-cooling system is limited tothe preliminary study pf the system design and system reliability. As the systemvacuum is free from the constraints of the externa] environment and plant conditions,the vacuum can be adjusted artiifcially with the operation of system equipment. Theselection of the vacuum in the operation of the system and the best vacuum economicevaluation analysis is not enough among the studies. This article mainly establishesthe system of economic indicators and the best vacuum model on the basis of theeconomic indicators, then take the example of Mondon area600MW units under theclimatic conditions to calculate the best vacuum.The article firstly introduced the structure pirnciple of composite air-coolingsystem. On this basis, we analyses production, energy-consuming equipment ofcomposite air-cooling system and establish performance index of compositeair-cooling units, with comparison of direct air-cooling unit. For facilitating theprogram calculation, this thesis resorts to ammonia, water and steam heat parameterformula, and establishes a optimal vacuum calculation model of compositeair-cooling system under the equipment production, consumption of performance.The Vairable conditions calculation of the combined-cycle air-cooled system wascarired out under the example of600MW direct air cooling unit in Huolinhe, Thetheoretical optimum vacuum of the unit was got by anglicizing the composite air-cooling system equipment production, the amount of wasted work and theperformance of build models. Finally, combining the climatic conditions of the areaunit distribution, analysis of the economic effects on the vacuum selecting of the lowtemperature period and high temperature peirod was carired out. And calculation thewhole year best vacuum draw that annual income is the highest with systembackpressure is4.8kPa.Which can provide guidance for the design and operation ofthe unit. As well as provide the basis for further confirmed the feasibility of thecombined-cyce air-cooling system.