Current Status and Experimental Research of New Type Compressor Lubricant

Current Status and Experimental Research of New Type Compressor Lubricant

Newly developed high-quality products The high performance and reliability of the compressor not only depend on the design and manufacturing process of the compressor itself, but also have a lot to do with the compressor oil used for the new compressor. However, there are few experimental studies on lubricants suitable for new compressors, and this situation has affected the development of compressors. The strategic cooperation between compressor manufacturers and lubricating oil manufacturers with scientific research capabilities is necessary. Sophisticated compressor oil will maximize the functions of newly developed premium compressors.

1. Current status of new product compressor oil

If the compressor is in the research and development period, the undisputed approach is to find a kind of lubricant that is considered usable to try. In the later stage of the compressor research and development, people often overlook the more suitable research of lubricants. An easy way makes the search for a more suitable lubricating oil fall to nothing, and then it is spreading falsehoods and plagiarizing each other, and no one is willing to increase the cost of lubricating oil, causing the work of improving compressor performance and reliability in this regard to stagnate. before.

the reason is:

1) The compressor manufacturer lacks professional and technical personnel familiar with lubrication technology;

2) The lubricant manufacturer lacks a deeper understanding of compressor oil;

3) The idea of low cost has made this work uninterested.

The engine industry is much larger than the compressor industry, the competition is more intense, and the engine oil replacement cycle is short, which is in sharp contrast with the compressor status.

In fact, the top manufacturers in the compressor industry are secretly improving the technical research of lubricants through special lubricant manufacturers, so as to achieve and improve the adaptability of lubricants, making their compressors more reliable than the first two in the group. Examples can illustrate the importance of compressor oil to compressor adaptability.

An example is: Dresser’s nearly 100 steam turbine-driven piston compressors abroad have been running continuously, while the two steam turbine-driven piston compressors purchased by Luxi Fertilizer Plant from Shanghai Dresser have Accidents frequently occur (including coupling failures, high-speed shaft fractures of reducers, etc.). The factory has replaced high-flexible couplings with high-priced reduction boxes and replaced the reducers. Finally, the steam turbine and steam turbines were overwhelmed. Reducer, and revise the foundation, change to synchronous drive. Who knows the twists and turns, hardships, a large amount of personnel and a waste of funds? Motors. On the contrary, okmarts.com's steam turbine-driven piston compressors have been running smoothly. Many chemical companies have also gone to investigate and try to learn from them. Where is the problem?

The reducer and compressor of the steam turbine-driven piston compressor device generally share the same oil tank. The oil tank should be filled with anti-wear hydraulic oil, and its FZG gear failure level should not be less than 10. The key to the steam turbine-driven piston compressors of Shandong Jiutai Chemical Technology Co., Ltd. is that they use anti-wear oil; the continuous and stable operation of nearly 100 steam turbine-driven piston compressors of Dresser abroad High FZG gear failure grade that benefits foreign compressor oil. There is a common fact that the speed-increasing gearboxes of domestic dry screw compressors are generally equipped with ordinary hydraulic oil. Many users of dry screw compressors have increased gearbox noise after 3 years, which hurts the dry screw main engine. Even buying dry screw air compressors of major foreign brands is not immune. But often the same company’s dry screw air compressor is rarely seen abroad.

　Many domestic large cotton spinning mills eliminated expensive brand-name oil-free screw air compressors by themselves and switched to SULLAIR 24KT screw air compressors + post processors. Some compressor experts do not understand the knowledge of lubricating oil, resulting in the inability to use lubricating oil correctly, making expensive dry screw air compressors unreliable.

2. More suitable for the development of compressor lubricants

Different gas compressors, especially screw compressors, have different lubricating oil matching requirements. The base oil and additive formula of compressor oils that are more suitable for new compressors should follow:

Lubricants developed for new high-quality compressors should be combined by compressor experts and lubricating oil experts. Through the analysis of lubricating oil samples, preliminary design of the functional requirements and cost requirements of the compressor oil, preliminary design of formulas, trial adjustment of oil samples, and pass Rack test and simulation bench test, optimize the formula, and develop different grades of applicable oil products.

(1) For new compressors with different key functional requirements, the matching new compressor oil should also be different. For example: air compressors with high energy efficiency are required. The focus of new compressor oil is to support air compressors to reduce energy consumption. Lubricant manufacturers generally use good oiliness agents and high-efficiency friction reducers in order to reduce the friction coefficient of compressor oil. But this alone will not achieve the desired effect, and the contribution rate of this action to energy efficiency will not exceed 1%.

To achieve the desired effect, the methods that can be followed are:

1) Use base oil with high adhesion;

2) Pursue the best viscosity

The best combination of sealing effect and frictional power consumption 4) Minimize the abrasion of the air compressor, extend the life of the air compressor and its parts as much as possible, so that the efficient working condition of the air compressor can reach 5 years or more.

(2) The other R&D requirements are:

1) Research on the adaptability of compression medium and compressor oil

Different compression media have more suitable base oils and matching additives. If you can master the latest and most reasonable base oils and matching additive technologies, it is possible to develop suitable new compressor oils.

2) Oxidation speed control

For compressor oils made from hydrocarbon base oils that are used in large quantities, controlling the oxidation rate is very important.

Anti-oxidation experimental research should mainly follow the method of GB/T12581-2006 (ASTM D943), ASTM D2112, D2272 method; rotating oxygen bomb method; The PDSC method is suitable for short-term rapid experiments, and the data obtained by this method can be analyzed and compared with the data obtained by the above two methods

Antioxidant technology is constantly developing. The performance of a single antioxidant and the synergistic effect of different antioxidants are very different; some other additives also have antioxidant effects, and the synergistic effect of these additives and antioxidants will also have some clues. And puzzling.

The function and life of new compressor oil largely depend on the oil's anti-oxidation level.

3) Acid value control

　The acid value control should use the GB/T12581-2006 (ASTM D943) method to study the formula and life of the new compressor oil. If the total acid value is well controlled, it will ensure that the new compressor is not easy to rust, and the reliability of the compressor will be improved accordingly.

4) Viscosity control

The viscosity range of the compressor oil available for the same compressor is wide, but different optimal viscosities are required for different compressor functions. This problem has not yet been agreed by the compressor industry. Sophisticated control of the viscosity of the new compressor oil will make the new compressor more advantageous and may receive unexpected results.

Compressor oils that compress different gases (mainly oil-injected screw compressor oils) vary greatly in viscosity values, and experiments with actual gases will be more targeted. Accelerated and variable temperature simulation experiments are effective methods that can be one step ahead of others to achieve experimental success.

5) FZG gear failure grade should be greater than 10. The relevant DIN standards and South Korea’s SK company require the FZG gear failure grade of compressor oil to be greater than 10. However, other lubricating oil manufacturers have a lot of criticisms about this. You should understand theirs from many examples. The regulations are not without reason. The aforementioned steam turbine-driven piston compressor is an amazing example, and the gear and bearing wear speed of many dry screw compressor speed-increasing boxes is even more difficult to satisfy. The reason is that the wear resistance is poor and the FZG gear failure level is too high. Caused by low.

3. Screw compressor oil needs special simulation test. In fact, many standard test methods of lubricating oil belong to simulation test. For example, four-ball friction test machine is an extreme load test. Its load is 5000-10 times the actual load. The contact load of gears can reach one-tenth of the maximum non-seizure load PB. The general friction load is only 1/5000 of the maximum non-seizure load PB, and the load of ball bearings is 1/20-100. The difference between this simulation experiment and actual friction lies in the continuity of the load. The load applied by the four-ball machine to the friction surface is a continuous load, while the actual friction load is a pulsating load. The low load with gaps on the friction surface becomes the recovery period of the friction surface. Therefore, the four-ball friction testing machine is an extremely harsh test method. However, the lubrication industry has always regarded this method as a sacred method, and many friction and wear scholars do not believe that the test method of the four-ball friction testing machine is effective and relevant.

Lubricants generally need to undergo some bench tests, and some engine oils require bench tests before they can be put into use. The bench test is a simulation test that is relatively close to the real working conditions.

In the high-end vehicle gear oil standard, a series of gear bench evaluations are required, including low-speed high-pressure torque, high-speed low-torque gear test; impact negative pressure gear test; reduction box corrosion test and oil thermal oxidation stability gear test. There are many single-cylinder bench test methods for evaluating internal combustion engine oils, such as Pete W-1, AV-1, AV-B, Lebek L-38 and domestic 11005, 1135 single cylinders, which can be used to evaluate different grades of internal combustion engine oil. The current API quality classification standard for internal combustion engine oil stipulates that diesel engine oil should be assessed with Caterpillar, Mack, Cummins, single-cylinder and GM multi-cylinder; for gasoline engine oil, MS program ⅡD (corrosion and wear resistance) ⅢE (high temperature oxidation) VE (low temperature) Sludge) and other tests.

And the bench test of compressor oil is really rare

Conditional manufacturers should carry out bench tests and simulation experiments of compressor oil to change the current chaotic conditions of compressor oil life.

Some lubricating oil manufacturers have used GB/T12581-2006 (ASTM D943), rotating oxygen bomb, infrared and RULER methods for some advanced compressor oil tests, and obtained some data, but it is not a real bench test.

This method is different from the temperature-programmed PDSC method. The temperature programmed PDSC method measures the initial oxidation temperature, and samples with high initial oxidation temperature have good oxidation resistance. Similarly, this method is suitable for the research of new oil products and the identification of the antioxidant properties of different oil products. Because the initial oxidation temperature deviates too far from the actual test temperature, the correlation with the actual service life of the oil is weak.

　PDSC constant temperature method is to measure the oil oxidation induction period, which is similar to the rotating oxygen bomb method

Based on this consideration, the calculation formula for the true life of compressor oil described in the article "Research on the Evidence of the Calculation Formula for the True Life of Compressor Oil" published in the previous issue of this journal is based on this consideration. The total base number coefficient is not included in the formula and should be reserved as a technical measure for lubricant manufacturers to improve oil quality.

5. Manufacturers of advanced compressors need to have strategic cooperation with lubricant manufacturers

The cooperation between advanced compressor manufacturers and technical lubricant manufacturers to develop new compressor oils is the only way to improve compressor oils.

Shenyang Blower Group, a leading compressor company in China, has already started this kind of cooperation. On September 11, 2015, Hetai Co., Ltd. and Shenyang Blower Group Wind Power Co., Ltd. signed the "Special Lubrication Strategic Cooperation Framework Agreement" to strengthen the special lubricants for wind power generation. Strong alliances in the field, complementary advantages. The two parties reached a consensus to comprehensively cooperate in the field of special lubricants used in wind turbine main gearboxes, generators, main bearings, tuning bearings, yaw bearings, and yaw open gears involved in wind power self-support and undertaking projects. As a rising star in the industry, Shen Gu

Shengu Wind Power has achieved impressive industry performance in the upstream gearbox R&D and manufacturing, wind farm engineering design, construction, general contracting, operation and maintenance in this field. Hetai Co., Ltd. took the lead in the industry to obtain Flender fully synthetic anti-micropitting gear oil and Denison HF-0 hydraulic system oil international certification, and developed a series of industry-leading biodegradable wind power lubricants. This cooperation will greatly enhance Hetai's brand awareness in the field of wind power, promote the localization of wind power lubricants, gradually break the long-term monopoly of foreign brands, and further promote the company's special lubrication integration solution provider; Brand positioning and development strategy.

Due to the huge wind power equipment, overhead installation, harsh operating environment, difficult repair, high repair cost, high life expectancy, and high requirements for lubricants. Although they are currently working on wind power projects, this kind of cooperation will eventually develop into a new way of cooperation for compressor oil.