阅读说明：本技术 一种从摩擦性能角度判断汽轮机油使用性能的方法 (Method for judging service performance of steam turbine oil from friction performance perspective ) 是由 张继平 戴媛静 张晨辉 于 2019-07-24 设计创作，主要内容包括：本发明提供了一种从摩擦性能角度判断汽轮机油使用性能的方法,把SRV试验用试盘打磨平整,超声清洗试盘和试球；在SRV试验机上安装试球和试盘,将试油滴到试盘上,在合适试验条件进行试验；试验结束后,清洗试盘,使用金相显微镜测量试盘磨斑宽度,使用三维白光干涉仪测量试盘磨斑深度和磨损体积；在用油磨损体积是新油磨损体积的2.5倍以上时,判断油品存在较为明显的劣化趋势,需要对油品进行干预。本发明有效的解决了现有技术中,无法判断机油的摩擦性能的问题。(The invention provides a method for judging the use performance of steam turbine oil from the angle of friction performance, which comprises the steps of polishing a test disc for an SRV test to be flat, and ultrasonically cleaning the test disc and a test ball; installing a test ball and a test disc on an SRV tester, dripping test oil on the test disc, and testing under proper test conditions; after the test is finished, cleaning the test disc, measuring the width of the grinding spot of the test disc by using a metallographic microscope, and measuring the depth and the wear volume of the grinding spot of the test disc by using a three-dimensional white light interferometer; when the abrasion volume of the used oil is more than 2.5 times of the abrasion volume of the new oil, the oil product is judged to have a more obvious deterioration trend, and the oil product needs to be intervened. The invention effectively solves the problem that the friction performance of the engine oil cannot be judged in the prior art.)

1. A method for judging the service performance of steam turbine oil from the aspect of friction performance is characterized in that: polishing a test disc for an SRV test to be flat, and ultrasonically cleaning the test disc and a test ball; installing a test ball and a test disc on an SRV tester, dripping test oil on the test disc, and testing under proper test conditions; after the test is finished, cleaning the test disc, measuring the width of the grinding spot of the test disc by using a metallographic microscope, and measuring the depth and the wear volume of the grinding spot of the test disc by using a three-dimensional white light interferometer; the test conditions comprise that the test time is 10-60 minutes, the test temperature is 40-100 ℃, the test load is 50-150N, and the test frequency is 20-50 Hz; when the abrasion volume of the used oil is more than 2.5 times of the abrasion volume of the new oil, the oil product is judged to have a more obvious deterioration trend, and the oil product needs to be intervened.

2. The method of determining turbine oil service performance from a friction performance perspective of claim 1, wherein: the surface roughness of the test disc after polishing is 20-100 nm.

3. The method of determining turbine oil service performance from a friction performance perspective of claim 2, wherein: the roughness is between 40nm and 60 nm.

4. The method of determining turbine oil service performance from a friction performance perspective of claim 1, wherein: the test conditions comprise that the test time is 30-60 minutes, the test temperature is 50-70 ℃, the test load is 80-100N, and the test frequency is 40-50 Hz.

5. The method of determining turbine oil service performance from a friction performance perspective of claim 1, wherein: test discs for the SRV test were sanded using 80, 240, 400, 1200 and 3000 mesh sand in that order.

6. The method of determining turbine oil service performance from a friction performance perspective of claim 1, wherein: cleaning the polished test disc in an ultrasonic cleaner by taking petroleum ether with a boiling range of 60-90 ℃ as a medium; after the test is finished, the surface of the test disc is cleaned by using petroleum ether with a boiling range of 60-90 ℃.

Technical Field

The invention belongs to the technical field of lubricating oil detection, and particularly relates to a method for judging the use performance of steam turbine oil from the aspect of friction performance.

Background

The requirement of the steam turbine oil, particularly the steam turbine oil used in a power plant, on the service life is higher, and at present, most power plants judge the performance of the used oil according to GB/T7596-2017 mineral turbine oil quality in power plant operation. The items listed in this standard are all physicochemical indices such as viscosity, acid number, open flash point, anti-foam, rotating oxygen bomb, anti-emulsification, particle contamination level, antioxidant content, etc. These indices reflect the degree of degradation of the physical and chemical properties of the oil, but do not reflect changes in the frictional wear properties of the oil.

With the improvement of the steam turbine technology, the working parameters of the steam turbine are gradually improved, the steam pressure is improved from 10MPa to 32MPa, and the steam temperature is improved from 450 ℃ to 600 ℃. These changes result in increased operating temperatures of the turbine oil and increased oxidation stability requirements for the oil. In addition, as the steam pressure is increased, the steam turbine shafting is lengthened, and the fluid seal clearance is reduced, the steam turbine is more prone to dynamic faults such as collision and friction, oil film vortex motion and the like, and the dynamic faults have higher requirements on the oxidation resistance and frictional wear resistance of the steam turbine oil.

in order to save cost and ensure normal operation of a steam turbine unit, the steam turbine oil used in a power plant is generally not replaced, so that the steam turbine oil is required to have stable performance and particularly has longer service life. However, the turbine oil running over time may have a performance degradation problem, which not only degrades the physical and chemical properties, but also causes a deterioration in the friction properties, which aggravates the wear of the bearing pads. Usually, the power plant will periodically collect oil samples for analysis to determine whether the properties of the oil meet the use requirements.

Table 0 shows the mineral turbine oil quality during operation of the GB/T7596-2017 power plant. As can be seen from table 0, all the items tested were physicochemical properties, and no frictional properties were involved.

TABLE 0 mineral turbine oil quality in power plant operation

Through data such as friction coefficient, wear volume, the friction performance can reflect the good and bad of oil performance more directly perceived, and can reduce the detection project.

If the in-use turbine oil is evaluated only from the physical and chemical properties, the problem that the physical and chemical properties meet the quality requirements but the frictional wear performance is obviously reduced may occur, so that it is necessary to select appropriate test conditions to evaluate the frictional wear performance of the in-use turbine oil. The lubricating state of the turbine is judged by combining the changes of the physical and chemical properties and the frictional wear performance of the turbine oil, and necessary measures are taken to ensure the effective lubrication of the turbine.

Because the turbine oil does not contain an extreme pressure antiwear agent, the friction performance of new oil and used oil cannot be judged by using a four-ball test, and the bearing capacity and the antiwear performance of the turbine oil are almost not different. And therefore needs to be judged using other methods. How to judge the friction performance of the oil in use becomes an urgent problem to be solved.

Disclosure of Invention

In view of the above, the present invention is directed to a method for determining the service performance of a turbine oil from the perspective of friction performance, and more particularly, to a method for determining the service performance of a turbine oil. The method can obviously judge the service performance of the steam turbine oil, and forms a method for judging the service performance of the steam turbine oil from a friction angle.

A method for judging the service performance of steam turbine oil from the angle of friction performance comprises the steps of polishing a test disc for an SRV test, and ultrasonically cleaning the test disc and a test ball; installing a test ball and a test disc on an SRV tester, dripping test oil on the test disc, and testing under proper test conditions; after the test is finished, cleaning the test disc, measuring the width of the grinding spot of the test disc by using a metallographic microscope, and measuring the depth and the wear volume of the grinding spot of the test disc by using a three-dimensional white light interferometer; the test conditions comprise that the test time is 10-60 minutes, the test temperature is 40-100 ℃, the test load is 50-150N, and the test frequency is 20-50 Hz; when the abrasion volume of the used oil is more than 2.5 times of the abrasion volume of the new oil, the oil product is judged to have a more obvious deterioration trend, and the oil product needs to be intervened.

Preferably, the surface roughness of the test disc after polishing is between 20 and 100 nm; preferably, the roughness is between 40 and 60 nm.

Preferably, the test conditions comprise the test time of 30-60 minutes, the test temperature of 50-70 ℃, the test load of 80-100N and the test frequency of 40-50 Hz.

preferably, the test disc for the SRV test is ground by using 80, 240, 400, 1200 and 3000-mesh sand in sequence; cleaning the polished test disc in an ultrasonic cleaner by taking petroleum ether with a boiling range of 60-90 ℃ as a medium; after the test is finished, the surface of the test disc is cleaned by using petroleum ether with a boiling range of 60-90 ℃.

Compared with the prior art, the method for judging the service performance of the steam turbine oil from the friction performance angle has the following advantages:

The method of the invention uses an SRV testing machine to carry out an effective testing approach, and can obviously judge the service performance of the steam turbine under proper conditions, thereby forming a method for judging the service performance of the steam turbine from the friction angle.

Drawings

FIG. 1 is a graph of the SRV friction coefficient of a fresh/in-service turbine oil of example one;

FIG. 2 is a SRV coefficient of friction for a fresh/in-service turbine oil of example two;

FIG. 3 is a SRV coefficient of friction for a fresh/in-service turbine oil of example three;

FIG. 4 is a SRV coefficient of friction for a fresh/in-service turbine oil of the fourth example;

FIG. 5 is a SRV friction coefficient for a fresh/in-use turbine oil of example five;

FIG. 6 is a SRV coefficient of friction for the fresh/used turbine oil of comparative example 1;

FIG. 7 is a SRV coefficient of friction for the fresh/used turbine oil of comparative example 2;

FIG. 8 is a graph of the SRV friction coefficient for the new/used turbine oil of comparative example 3.

Detailed Description

Unless defined otherwise, technical terms used in the following examples have the same meanings as commonly understood by one of ordinary skill in the art to which the present invention belongs. The test reagents used in the following examples, unless otherwise specified, are all conventional biochemical reagents; the experimental methods are conventional methods unless otherwise specified.

The present invention will be described in detail with reference to examples.

The specific test steps are as follows:

1. The preparation process comprises the following steps: 1) polishing the test disc of the SRV test by using 80, 240, 400, 1200 and 3000-mesh sand paper in sequence to ensure that the surface of the test disc is smooth and has no scratch; 2) cleaning the polished test disc in an ultrasonic cleaner by using petroleum ether (with a boiling range of 60-90 ℃) as a medium; 3) and measuring the surface roughness of the cleaned test disc by using a three-dimensional white light interferometer, wherein the measured value is between 30 and 60nm, and if the measured value is not in the interval, polishing, cleaning and measuring the test disc again until the surface roughness meets the requirement.

2. The test operation process comprises the following steps: 1) mounting the test ball and the test disc on an SRV testing machine, and dripping test oil onto the test disc to enable the test oil to cover the surface of the test disc; 2) selecting proper test temperature, load, frequency, stroke (2 mm), time and the like to start the test; 3) after the test is finished, storing test data, and unloading the test ball and the test disc; 4) dipping and washing a test ball and a test disc by absorbent cotton (the solvent is petroleum ether with a boiling range of 60-90 ℃); 5) and (4) mounting the cleaned test ball and test disc on an SRV testing machine, and repeating the steps to perform the next oil sample test.

3. And (3) comparing test results: 1) processing test data, and drawing a friction coefficient curve graph of the test oil by using corresponding software; 2) measuring the width of the disc grinding spots by using a metallographic microscope; 3) measuring the wear volume of the test disc grinding spots by using a three-dimensional white light interferometer; 4) the friction coefficient, the width of the wear plaque, the depth of the wear plaque and the wear volume of the fresh and used oils were compared.