The shaft seal heater and shaft seal cooler are used to extract the steam and gas mixture from the steam seal system of the steam turbine, preventing steam from flowing from the end steam seal to the turbine room and oil system, polluting the environment and damaging the oil quality. These vapor compounds enter the shaft seal cooler and are cooled into water, heating the condensed water. The remaining uncondensed gas is discharged into the atmosphere.

The shaft seal heater is also known as the shaft seal cooler or steam seal heater. The modern production of steam turbines adopts a self sealing type of shaft seal system, and the thermal system only has one shaft seal cooler. Different factories also have different names, which refer to the same equipment. In the early 200MW units, there were shaft seal heaters and shaft seal coolers installed on the thermal system. The shaft seal heaters used high-pressure shaft seal steam as heating steam, which was higher than the pressure of the 8 # low-pressure heater, in order to recover the heat and working fluid of the shaft seal steam. The shaft seal cooler was used to cool the shaft seal extraction steam (or to use the shaft seal extraction steam as heating steam), and the cooler was in a vacuum state during operation. Other units usually only have one shaft seal cooler installed.

The air that enters with the shaft seal steam is led to the expansion pipe of the water jet steam extractor through a connecting pipe, and is extracted by the negative pressure of the latter to ensure the micro vacuum state of the shaft seal heater. In this way, the chambers of each shaft seal also maintain a slight vacuum, and the shaft seal steam does not leak out.

Shaft seal heater (shaft seal cooler, steam seal heater) - output voltage:

Shaft seal heater and shaft seal cooler are devices that recover shaft seal steam and use its heat to heat condensate, reducing energy loss and improving unit heat efficiency. When the steam turbine adopts an internal leakage shaft seal system, a shaft seal heater (shaft seal cooler, steam seal heater) is generally installed to heat condensate or desalinated water, recover shaft seal steam, reduce shaft seal steam and heat loss, and improve the environmental conditions of the workshop.

Working principle of shaft seal heater (shaft seal cooler, steam seal heater):

The shaft seal heater, shaft seal cooler, and steam seal heater are connected by connecting pipes to the expansion pipe of the water jet steam extractor with the air entering the shaft seal steam, and are extracted by the negative pressure of the latter to ensure the micro vacuum state of the shaft seal heater. In this way, the pressure of the chambers connected to each shaft seal and the shaft seal heater decreases, and the shaft seal steam does not leak out. Some also use shaft seal air extractors or exhaust fans to create negative pressure and discharge impurities. The shaft seal air extractor is generally a steam injection air extractor, and its supporting shaft seal heater is divided into two parts. The steam compound enters, the steam is condensed, the air is sucked, and combined with the working steam. After expansion, it is discharged. The steam is condensed, and the air is discharged through the exhaust port.

Technical parameters of shaft seal heater, shaft seal cooler, and steam seal heater:

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