Replacing the tube of the shaft seal heater

Lianyungang Lingdong Electromechanical Equipment Co., Ltd. is a manufacturer of shaft seal heaters, and also undertakes the transformation of shaft seal heater pipes, including copper pipes, stainless steel pipes, boiler pipes, etc. According to customer needs, the replacement, repair, installation, and restoration of the relevant shaft seal heater pipes must be carried out. The original equipment must be sent to our company for pipe bundle replacement. The customer needs to provide the original shaft seal heater equipment drawings for us to report and budget costs. Welcome to contact us if you need to replace the tube of the shaft seal heater.

The shaft seal heater is a device that recovers the shaft seal steam and uses its heat to heat the condensate, reducing energy loss and improving the heat rate of the unit. When the steam turbine adopts an internal leakage shaft seal system, a shaft seal heater (shaft seal cooler) 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.

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 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.

Used to extract the steam gas mixture from the steam turbine seal system, to prevent steam from flowing from the end seal to the turbine room and oil system, thereby 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 replacement period for the shaft seal heater varies depending on the size of the equipment, such as 20m ² The replacement period for the shaft seal heater pipe refers to about 35-40 days after the equipment is sent to the company for completion. We suggest that the manufacturer of the shaft seal heater replace the tube and send the equipment to our company for replacement, which not only saves time but also costs. If on-site pipe replacement, installation, and restoration are required, the cost will be several times higher. So we suggest replacing the pipes of the shaft seal heater in our company, including hanging and replacing pipes, threading and expanding pipes, welding pipes, water pressure testing, and so on. They are all quite convenient. We will restore the equipment and repaint it upon shipment. Some manufacturers will only send us the equipment core for replacing the shaft seal heater tube, or directly ask us to make a tube core. In this way, we cannot conduct a water pressure test on the shaft seal heater, and we cannot ensure that the pipe core is properly installed in the equipment body.

Many manufacturers of shaft seal heaters need to replace their pipes, and they all ask us why the construction period needs 35-40 days? What I want to say is that all of our heat exchange tubes need to be produced and processed on site, and there are no ready-made tubes because the size of the tubes in each tube change equipment does not match, which leads to us squeezing a lot of tubes in the company, and this cost is very high. So our company cannot afford it. So the replacement period for the shaft seal heater is mostly focused on the production and processing of pipes and the bending of U-shaped pipes. The consumption time of pipes is about 30 working days. The remaining 5-10 days are the time for us to replace the pipes of the shaft seal heater.