Influencing factors analysis on the piping thermal efficiency of PWR nuclear power plant secondary circuit system

Firstly, computing formula of piping thermal efficiency and various kinds of pipe losses were introduced in this paper on the definition of piping thermal efficiency. Aiming at factors affecting piping thermal efficiency and the whole plant efficiency of PWR nuclear power plant, it was analyzed that the influence of these factors change affecting piping thermal efficiency and the whole plant efficiency of PWR nuclear power plant. Taking a 990MW nuclear power plant for example, the influence of leaking steam of main steam pipe, auxiliary steam, radiation thermal loss of main steam pipe, blowdown from steam generator and all that on piping thermal efficiency, steam power transition system cycle thermal efficiency and the whole plant efficiency were analyzed by calculating. The results show that the above-mentioned factors lead to the reduction of the piping thermal efficiency and the whole plant efficiency, but the influence mechanism on the whole plant efficiency is different on these influence factors.