以往的循环压力情况公用事业电站目前在考虑选用新的发电设备时面临着日益增多的选择因素。其中之一,即为循环压力问题。新装的机组是采用亚临界压力(一般为169大气压)的汽包炉,还是采用超临界压力(246大气压)的设计?在作出抉择前需要考虑一些因素。首先,需考虑的是该两种循环压力在历史记录上的事故停运率(FOR)。图1及图2列示了,最近期间报道的该两种机组有关这 Past Circulatory Stress Utility utilities are currently faced with an increasing number of choices when considering the use of new power generation equipment. One of them is the issue of cycle pressure. Is the newly installed unit a drum oven with subcritical pressure (typically 169 atmospheres) or a supercritical (246 bar) design? There are a number of factors to consider before making a decision. The first thing to consider is the accident shutdown rate (FOR) for both cyclic pressures in the history. Figures 1 and 2 show the two units reported in the most recent period