Efficiency of Multistage Filtration of Turbine Oil in the Oil-Supply System of Turbo Units

Abstract

The efficiency of multistage filters of the main oil tank (MOT) is analyzed. The efficiency of sequentially installed filters is determined by a power function in which the base is the stage skip factor W_in (assuming W_in = const for all filtering stages) and the exponent is the number of filtering stages n. Under the operating conditions of the hydraulic system, contaminants continuously enter the system and are removed by the filter. How the change in the transmittance W_i in the process of multistage filtration affects the purity of the oil in the operating system is analyzed. Oil tank filters were upgraded at the K-200-12.8 LMZ turbine unit (station no. 9) at Yuzhnouralskaya GRES. Instead of brass woven meshes, a filter material made of polyamide monofilaments (polyamide filter material) was installed. After the modernization of the coarse and fine filters, the oil became cleaner in the oil-supply system of the K-200-130 turbine unit (station no. 9), the amount of solid particles in it (in samples from the clean compartment of the MOT) with sizes of more than 10 microns decreased by 68 times, and the amount of water in the oil decreased by approximately three times; industrial purity corresponds to the eighth class of GOST 17216-2001. In practice, the operation of coarse and fine filters in one and two stages was also analyzed. When switching from single-stage to two-stage filtration, the purity of the oil became higher, and the amount of solid particles in it with sizes of more than 5 microns decreased by three times, while the amount of water in the oil by approximately 12 times. Increasing the number of filtration stages significantly increases the purity of the filtrate.