MS9001E gas turbine generator set simple cycle with a basic load of 180 heavy fuel oil when the power of 13.8MW, pressure ratio of l2.3. The overall structural layout No. 2 bearing arranged in the compressor and turbine between the No. 3 bearing arranged in the turbine exhaust diffuser. Compressor inlet guide vane adjustable through 9OTV-1 control. Fuel is supplied by the main fuel pump and the fuel bypass valve of the main fuel pump regulates the amount of fuel in the unit to control the load changes. The fuel bypass valve is controlled by 65FP-1, which has been tripped several times since the second half of 2002 due to a 65FP-l failure that causes a delay in starting up or fluctuating fuel levels. 1. Failure and Cause Analysis 65FP-1 is an electro-hydraulic converter (or servo valve), when the input coil current signal changes, the torque motor drives the armature and flexible pipe action, causing the first stage on both sides of the injection tube Of the flow changes, and then change the pressure on both ends of the second stage spool valve and slide action, the fuel tank into the oil or oil, which led to fuel bypass valve work. Fuel bypass valve fault phenomenon there are two main: First, the boot process, after the ignition fuel flow FQL Deviation from the flow of the input signal FSR, excessive flow caused by excessive flow of protection action and failed to start, and sometimes there is no flow or traffic is very large and start failure. The other is that during normal operation, fuel flow FQL momentarily deviates from the flow input signal FSR, and fuel flow is either dragged or drooped in a few seconds, but recovered in seconds. When the fuel flow decreases, the load decline, immediately and recovery, the general does not occur trip, and when the fuel flow on the Biao, the load increases, it is possible to cause the exhaust temperature is high and the trip. 65FP-1 electro-hydraulic converter fails, once the disintegration of clean-up, from the disintegration of the situation, there are a lot of sludge on the oil filter, slide the metal surface can scratch a layer of paint deposits, was hard translucent brown coating Floor. This sludge and varnish is the cause of servo valve failure. Causes hydraulic control valve failure seems to be the deterioration of oil quality, but conventional lubricants test indicators (viscosity, cleanliness, acid value, etc.) are in line with the requirements, and lubricating oil to the hydraulic oil has a 0.5μm fine filter, filter pressure Poor Normal, hydraulic controls did not show any sign of improvement despite oil filter changes. Further (May 2002) analysis of the lubricant index, oil antioxidant test results show that No. 7, Millipore sludge machine has reached 4.21mg / 100mL and 6.12mg / 10OmL. Due to the selection and schedule of spare oil, TURBO GT32 Lubricant No. 8 was first replaced in early 2003. After replacement, there is no recurrence 65FP-1 jam problem. However, the No. 7 machine is not replaced, the problem still exists, but there is a serious trend. By the middle of March, 2003, the No.7 engine oil was re-sampled, the Millipore sludge reached 9.16mg / 100mL, replaced with TURBO GT32 oil during the overhaul in April, and there was no 65FP-1 card after several times of on / off replacement Astringent phenomenon. Lubrication oil gas turbine lubricating oil in extremely harsh high temperature oxidation environment, Babbitt bearings can withstand temperatures as high as 120 ℃, but the sealing air around the bearing temperature is higher, where the film temperature up to 130 ℃ , Some even up to 140 ~ 150 ℃, which has reached or exceeded the temperature limits of mineral oil and additives. Coupled with exposure to the air seal, the oxidation of oil is very severe. Because of the biggest challenge encountered in the operation of gas turbine lubricants is the high-temperature oxidation, so the high temperature oxidation performance of the lubricating oil specifications is the most noteworthy indicator. Federal oxidation test can better reflect the oil at high temperature anti-aging, anti-sludge generation. Federal oxidation test, the oil was added as a catalyst of five metals (copper, silver, aluminum, magnesium, iron), at 175 ° C, the air flow through 72h aging. Test reports of oil viscosity changes after aging, the increase in acid value, sludge content. The oil underwent the most demanding high temperature oxidation test in this test. Conventional tests focus more on viscosity and acidity, but enough attention is paid to the threat of hydraulic controls on the gas turbine engine oil to be used as a hydraulic fluid. After comparing a variety of technical and economic indicators of lubricants, choose Shell's TURBO GT32. It is formulated by base oil XHVI and special high temperature additive. XHVI base oil is a synthetic hydrocarbon oil, it is unique in its own oxidation resistance, not easy to generate oxides, while having good polymer solubility. The sludge generation test (175 ℃, 72h), TURBOGT only 35mg / 100mL, and mineral gas turbine oil up to 750 ~ 1000mg / 100mL. 3 oil change work in order to maximize the removal of residual oil in the system, sludge, sediment, paint and other impurities in the maintenance process, after cleaning the tank and piping, repeatedly washed with rinse oil, and then cleaned, and then Rinse with working oil, add new working oil after discharge. Oil change, ①try to drain the old oil to reduce the pollution of flushing oil. In the 60 ~ 70 ℃ oil temperature emissions, remove the fuel tank, cooler and other large container oil, open the low valve and pipe fittings, replace all filters. ② flushing process, try to form a turbulent flow, the best temperature fluctuations in 30 ~ 80 ℃. In the inlet and return pipe to install the filter, when the filter pressure is too large, it should be promptly replaced. ③ heating oil, shall not exceed 88 ℃, the heater surface temperature shall not exceed 120 ℃, stop the oil circulation heater surface temperature shall not exceed 66 ℃. ④ separate cooler, servo valves, bearings and other sensitive components bypass. ⑤ working oil flushing the best temperature control in the oil at 60 ~ 70 ℃. ⑥ oil change, the extraction of oil samples comprehensive test, contrast with the new oil in the barrel. 4. CONCLUSIONS It is advisable to periodically conduct analysis tests on the lubricating oil quality of gas turbines, especially for the lubricating oil to be used as hydraulic oil, to conduct the rotary oxygen bomb test and the Millipore oil sludge content analysis. When the sludge content reaches 5mg / 100mL, oil change should be promptly, otherwise the sludge generation rate will speed up, to the hydraulic control of the threat. As the inevitable contact with high temperature lubricating oil and high temperature components, prone to oxidation, exacerbated the sludge precipitation, which is not suitable for use as hydraulic oil. Therefore, it is recommended to consider the design of gas turbine oil and hydraulic oil will be separated, so as to avoid hydraulic oil contact with high temperature components or media, and oil change, the oil change can be relatively small.