What are the causes of high exhaust temperature in steam turbines?

[MacLouis]

High exhaust temperature is generally caused by: 1. Circulating water system failure; 2. Water injection system failure; 3. Vacuum system leakage; 4. Shaft seal leakage; 5. Condensate system failure. Additional information: There is a corresponding relationship between exhaust temperature and condenser vacuum: If the exhaust temperature is high, check whether the spray water pressure and flow rate are too low, or if the water temperature is too high; also check if the spray nozzles or filters are clogged; try appropriately increasing the outlet vacuum level. In steam turbines, if the steam is insufficient to carry away the heat generated by the windage friction of the last few stages of blades, the exhaust temperature will abnormally rise. During the startup process, the exhaust temperature increases, so most units are equipped with low-load spray water devices. During steam turbine startup, steam is throttled and then passes through the nozzles to drive the governor stage impeller. After throttling, the entropy of the steam increases, and the enthalpy drop decreases, resulting in a higher exhaust temperature after work is done. Throughout the startup process before grid connection, the steam consumption is very low.