Spare oil supply device for main shaft bearing lubrication system of large generator set

Abstract

A backup oil supply device for the main shaft bearing lubrication system of a large generator set, including: an oil pump or a diaphragm pump, used to supply oil to the main shaft bearing of a generator set; wherein, the oil pump is driven by a steam or pneumatic driver, and the diaphragm pump is directly driven by steam or compressed air The driving medium pipeline is provided with a control valve group, which includes a hydraulic or pneumatic switching valve and a pneumatic regulating valve, which are arranged in series according to the flow direction of the driving medium, with the hydraulic or pneumatic switching valve in front for connecting The driving medium is turned on or off, and the pneumatic regulating valve is used to adjust the pressure of the driving medium to meet the rated working pressure of the driver; the hydraulic or pneumatic switching valve is connected in parallel with a solenoid valve as a redundant channel for the driving medium; When the valve is powered on, it receives the DCS signal to open, and it will automatically open when the power is off; the pneumatic control valve is connected in parallel with a throttle orifice. When the pneumatic control valve fails to open, most of the steam or gas required by the driver passes through the hole. plate into the drive, to ensure its minimum output.

Description

technical field [0001] The invention relates to a lubricating oil supply system for a main shaft bearing of a generating set in a power plant, in particular to a backup oil supply device for the main shaft bearing lubricating system of a large generating set. Background technique [0002] In modern power plants, whether it is coal-fired power generation, gas power generation, nuclear power generation or hydropower generation, in order to improve economic efficiency, the units are all developing towards large-scale, and the bearings supporting the rotor of the unit are all sliding bearings, and must be equipped with forced circulation lubricating oil Oil supply system, these oil supply systems have various forms, there are main oil pump - oil turbine system (such as figure 1 shown), the main oil pump-lubricator system (such as figure 2 shown), gear pump oil supply system and electric oil pump oil supply system (such as image 3 shown) and so on. Their main function is to ...

AI Technical Summary

Problems solved by technology

Later, as the unit capacity developed to hundreds of thousands of kilowatts or even millions of kilowatt-hours, its layout and installation became complicated and difficult (see Figure 4 ), for example, for a 600MW turbogenerator set, the high-level fuel tank that meets the requirements will weigh more than 100 tons, including oil weight, and it is almost impossible to install it in the existing plant. Even if it is divided into several small fuel tanks, the installation arrangement Difficult and complicates the system

In addition, the oil in the high-level oil tank needs to be returned to the lubricating oil tank when the unit is shut down, and the volume of the unit’s lubricating oil tank itself is relatively large, which makes its volume larger, so the arrangement of the lubricating oil tank and the high-level oil tank will bring great problems. difficulties, unless the plant space is increased, which will greatly increase the cost of the power plant

Of course, there is another way to add an auxiliary fuel tank to receive the oil return from the high-level fuel tank. This not only requires more space to place the auxiliary fuel tank, but also the return oil from the high-level fuel tank must pass through the main fuel tank and return to the auxiliary fuel tank. A pump must also be equipped when starting the machine again. The system becomes complicated by pumping the oil from the auxiliary tank back to the main tank

Finally, the high-level oil tank system seems simple, but in fact it must be carefully calculated. Its capacity and flow rate must match the coasting curve of each unit. During the high-speed process, the oil film thickness of the sliding bearing tends to become thinner gradually, once the oil supply is insufficient, the oil film may be destroyed

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