直接空冷机组高背压供热技术经济性分析

The Economy Analysis of the High Back Pressure Heating Technology on Direct Air-colled Unit

对国内首台直接空冷机组循环水高背压供热系统进行了介绍,对高背压供热方式下的经济性进行了分析。由于供热方式的改变,供热参数和背压变化引起蒸汽做功量的变化对机组供热经济性影响最大。通过具体推导和相关条件的简化,得到了供热经济性计算与判定的公式和准则。外部供热条件循环水流量和回水温度对供热经济性产生最直接的影响,机组排汽流量的变化也会对机组经济性构成影响。在循环水流量和环境条件相对稳定的情况下,可以以六段抽汽压力和回水温度来判断供热方式的经济性。根据不同的条件制定经济性判断准则,一方面可以用来指导项目的可行性研究,另一方面为运行过程中供热方式优化选择提供依据。

In this paper,the circulating water of high pressure heating systemin the first domestic direct air-cooled unit was introduced. The economy under the heating supply mode with high back pressure was analyzed. Due to the change of heating supply mode,the variation of the power outputis mainly caused by the changes of heating parameters and back pressure,which also have the greatest impact on the economy of the unit. By proper deduction and simplification,the formulations of the calculation and evaluation of heating efficiency was obtained. Under the external heating condition,the tempearature of circulating water and backwater have the largest impact on the economy of heating,and the mass flow change of the unit exhaust steam also has some influence on the unit economy. Considering a steady mass flow rate of circulating water and environmental conditions,the economy of different modes can be assessed by the pressure of the sixth steam extraction and the temperature of the backwater. The rules of economy evaluation methods can be obtained for different situations,which,on the one hand,can be used to guide the project feasibility investigation,and,on the other hand,can provide a basis for selecting the optimal heating mode.