Super-long-life gas turbine / steam turbine lubricating oil and preparation method thereof

Abstract

The invention belongs to the technical field of lubricating oil preparation, and particularly relates to super-long-life gas / steam turbine lubricating oil and a preparation method thereof.According to the technical scheme, the super-long-life gas / steam turbine lubricating oil is prepared in the mode that deeply-refined paraffin-based lubricating oil components are matched with a functional additive formula. The high-activity antioxidant oxygen agent can effectively capture oxidizing free radicals or peroxide free radicals. At the moment, the low-activity antioxidant can supply hydrogen atoms, so that the high-activity antioxidant is regenerated, and the long-term antioxidant efficiency is maintained. The oxidation stability (rotation oxygen bomb at 150 DEG C) exceeds 3500 minutes and is 2-4 times that of a conventional product, and the oxidation resistance of an oil product under a high-temperature working condition can be effectively ensured to be far superior to that of the conventional product.

Description

Technical Field

[0001] This invention belongs to the field of lubricating oil formulation technology, specifically an ultra-long life gas / steam turbine lubricating oil and its preparation method. Background Technology

[0002] The main functions of gas turbine oil are to reduce friction and wear on internal components of the gas turbine, dissipate heat, and act as hydraulic fluid in some speed control and control valves. By supplying an appropriate amount of gas turbine oil to form an oil film, direct contact between components is reduced, thereby reducing friction and wear. At the same time, it can also cool high-temperature components inside the gas turbine, maintaining their normal operating temperature.

[0003] With the continuous advancement of gas turbine manufacturing technology, from a gas turbine design perspective, increasing the inlet temperature can more effectively improve the thermal efficiency of the gas turbine. The inlet temperature of gas turbines has increased from 600-700℃ in the early days to over 1400℃ today. The increase in inlet temperature inevitably leads to an increase in exhaust temperature, causing the bearing oil film temperature at the exhaust end to reach 130℃.

[0004] The oxidation of petroleum products is a free radical chain reaction, consisting of four stages: chain initiation, chain propagation, branching reaction, and chain termination. Chain initiation requires specific temperatures, oxygen, and a metal catalyst. Once initiated, the chain propagation stage is a self-growing cycle that occurs rapidly until chain termination. Branching reaction is an oxidation reaction that occurs at high temperatures (above 120°C), and its occurrence significantly accelerates the second stage of oxidation. Therefore, temperature has a very significant impact on petroleum product oxidation.

[0005] Compared to conventional gas turbine oils, with the use of combined gas-steam cycle technology, they inevitably come into contact with water during use, and there may even be a situation where cooling water and water vapor mix in. Therefore, the oil must have sufficient water separation capacity.

[0006] Conventional gas / steam turbine oils typically use mineral base oils and conventional additive formulations, resulting in relatively weak high-temperature resistance and oxidation stability. Even after the thermal efficiency of gas turbine units has been improved, conventional gas / steam turbine oils are still used as the lifeblood of the lubrication system. During use, the service life of gas / steam turbine oils is shortened and sludge increases, which will inevitably lead to consequences such as filter clogging, insufficient oil supply, bearing wear, valve sticking, and speed regulation failure, ultimately causing losses due to abnormal shutdowns.

[0007] Improving the high-temperature resistance and oxidation resistance of oil products usually involves using synthetic base oils and matching additives, which will increase production costs accordingly. The prior art Chinese patent CN118546711A discloses an ultra-low sludge gas turbine oil composite agent, which consists of the following components: 50-70% antioxidant, 6-10% rust inhibitor, 6-12% extreme pressure anti-wear agent, 4-8% metal deactivator, 2-4% demulsifier, and the balance being base oil. The blended turbine oil exhibits excellent rotating oxygen bomb performance.

[0008] Existing technology, Chinese patent CN119220318A, discloses a turbine oil compound, a turbine oil, its preparation method, and its application. The turbine oil compound, based on a total mass fraction of 100 parts, comprises the following components: 60-80 parts antioxidant, 5-15 parts metal deactivator, 5-10 parts rust inhibitor, 0.5-5 parts demulsifier, and 5-30 parts cosolvent. The turbine oil of this invention contains the turbine oil compound, which effectively balances the oil's acid value, rust prevention, demulsification, and oxidation performance. Adding this compound to a suitable base oil and supplementing it with an appropriate amount of antifoaming agent yields an L-TSA turbine oil (Grade A) product that meets the requirements of GB 11120-2011 "Turbine Oils," and possesses characteristics such as long oxidation life, excellent rust prevention performance, and superior demulsification properties. Summary of the Invention

[0009] The rotating oxygen bomb test is an accelerated oxidation test that rapidly assesses the oxidation resistance of oils by simulating the high temperature, oxygen, and metal catalytic environment they face in actual use. The demulsibility test is a key test for evaluating lubricating oil performance, primarily used to determine the oil's ability to resist the formation of a stable emulsion and achieve rapid oil-water separation when in contact with water.

[0010] The existing technology disclosed in Chinese patent CN118546711A is an ultra-low sludge gas turbine oil compound. Although the turbine oil formulated with this compound has ultra-low sludge formation, its highest rotating oxygen bomb test result is 2015 min, which cannot meet the requirement of an ultra-long service life. Furthermore, the composition does not use phenolic antioxidants, which cannot guarantee the low-temperature oxidation resistance of the oil in gas-steam combined cycle turbines.

[0011] The existing technology disclosed in Chinese patent CN119220318A, which describes a turbine oil compound, a turbine oil, its preparation method, and its application, shows that the turbine oil prepared using this compound has a maximum rotational oxygen bomb test result of 765 minutes, which cannot meet the requirement for an ultra-long service life. Furthermore, GB 11120-2011 "Turbine Oils" requires an anti-emulsification time of no more than 30 minutes. With the use of combined cycle gas and steam technology, the oil will inevitably come into contact with water during use, and there may even be mixing of cooling water and water vapor. Therefore, the anti-emulsification time for gas / steam turbine lubricating oil should be at least no more than 15 minutes to meet the water separation requirements.

[0012] This invention uses deeply refined paraffin-based lubricating oil as raw material and is compounded with various additives. While reducing product costs, it combines the characteristics of ultra-long service life (≥3500 min at 150℃ in a rotating oxygen bomb) and excellent oil-water separation properties (≤15 min of anti-emulsification). It is suitable for lubrication of gas turbines, steam turbines, gas-steam combined cycle turbines, high-power supercritical steam turbines, industrial drive devices and control systems, etc.

[0013] The technical solution adopted by this invention to solve its technical problem is as follows: This technical solution, through the method of matching deeply refined paraffin-based lubricating oil components with functional additive formulations, produces an ultra-long-life gas / steam turbine lubricating oil comprising the following components: (1) Deeply refined paraffinic base oil 95-98 wt%; (2) Phenolic antioxidant 0.1-0.5 wt%, which is at least one of high-performance liquid phenol, liquid-shielded phenolic antioxidant, thiophenol-type high-efficiency antioxidant, or high molecular weight phenolic antioxidant. (3) 0.3-2.0 wt% of amine antioxidants, which are a combination of diphenylamine antioxidants and aromatic secondary amine antioxidants; (4) Demulsifier 0.01-0.05wt%, which is ethylene oxide / propylene oxide block copolymer ether; (4) Rust inhibitor 0.04-0.10 wt%, is an inorganic carboxylic acid compound; (5) 0.05-0.10 wt% of metal deactivator, which is at least one of 2,5-bis(tert-dodecyl dithio)-1,3,4-thiadiazole and 2,5-bis(alkyl dithio)-1,3,4-thiadiazole derivatives; (6) Extreme pressure anti-wear agent 0.5-1.0 wt%, which is at least one of triphenyl thiophosphate and tricresyl phosphate; (7) Pour point depressant 0.01-0.03 wt%, which is polymethyl methacrylate; (8) Antifoaming agent 0.001-0.003wt%, which is a complex of silicone and non-silicone antifoaming agents.

[0014] The preparation method of ultra-long life gas / steam turbine lubricating oil includes: adding antioxidant, demulsifier, rust inhibitor, metal deactivator, extreme pressure anti-wear agent, pour point depressant and base oil in sequence to a container, heating to 50-60℃, stirring and mixing evenly, continuing to add antifoaming agent, maintaining temperature and stirring evenly, and then filtering.

[0015] While ensuring air release and anti-foaming capabilities, the oil's oxidation resistance and oil-water separation capabilities have been improved, achieving a result of ≥3500 min under rotating oxygen bomb conditions at 150℃ and a demulsification result of ≤15 min, thereby improving the product's service life in gas turbines and gas-steam combined cycle equipment.

[0016] The beneficial effects of this invention are as follows: The ultra-long life gas / steam turbine lubricating oil and its preparation method described in this invention have the following beneficial effects: 1) This invention uses deeply refined paraffin-based lubricating oil, which has a lower production cost compared to synthetic lubricating oil; 2) Compared with existing gas / steam turbine lubricating oils, the present invention has a longer service life and excellent oil-water separation capability; 3) Demulsibility (40-37-3mL, 54℃) is less than 15min, which is half the performance requirement of conventional products; Three antioxidants are optimally combined. When amine and phenolic antioxidants with different antioxidant activities are used simultaneously, they exhibit a synergistic effect. AH is a highly sterically hindered or low-activity antioxidant, while BH is a low-sterically hindered or highly active antioxidant. BH reacts more readily with peroxide free radicals. The highly active antioxidant oxygen bomb effectively captures oxidizing or peroxide free radicals. At this point, the low-activity antioxidant can donate hydrogen atoms, allowing the highly active antioxidant to regenerate and maintain long-term antioxidant efficiency. Oxidation stability (rotating oxygen bomb 150℃) exceeds 3500 minutes, 2-4 times that of conventional products, effectively ensuring that the antioxidant capacity of oil products under high-temperature conditions is far superior to conventional products. Detailed Implementation

[0017] To make the technical means, creative features, objectives and effects of this invention easier to understand, the invention will be further described below in conjunction with specific embodiments.

[0018] Example 1 The implementation plan is to prepare ultra-long life gas / steam turbine lubricating oil No. 32. The implementation plans for ultra-long life gas / steam turbine lubricating oil in implementation plans 1-4 are detailed in Table 1.

[0019] Table 1

[0020] This product requires a rotating oxygen bomb time of ≥3500 min, an improved rotating oxygen bomb time of ≥85%, and demulsification (time for the emulsion layer to be reduced to 3 ml at 54℃) of ≤15 min, etc. For details of the main properties, please refer to Tables 2-1, 2-2, and 2-3.

[0021] Table 2-1

[0022] Table 2-2

[0023] Table 2-3

[0024] This invention uses deeply refined paraffin-based lubricating oil, which has a lower production cost compared to synthetic lubricating oils. Compared to existing gas / steam turbine lubricating oils, this invention has a longer service life and excellent oil-water separation capability; its demulsification rate (40-37-3mL, 54℃) is less than 15 minutes, which is half the performance requirement of conventional products; it preferably uses a combination of three antioxidants, and the simultaneous use of amine and phenolic antioxidants with different antioxidant activities has a synergistic effect; AH is a highly sterically hindered or low-activity antioxidant, while BH is a low-sterically hindered or highly active antioxidant. BH reacts more readily with peroxide free radicals.

[0025] Highly active antioxidant oxygen bombs effectively capture oxidizing or peroxidizing free radicals. At this point, the less active antioxidant can donate hydrogen atoms, allowing the highly active antioxidant to regenerate and maintain long-term antioxidant efficiency. Oxidation stability (rotating oxygen bomb at 150°C) exceeds 3500 minutes, which is 2-4 times that of conventional products, effectively ensuring that the antioxidant capacity of oil products under high-temperature conditions is far superior to conventional products.

[0026] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. An ultra-long life gas turbine lubricating oil, characterized in that: The ultra-long-life gas / steam turbine lubricating oil, formulated by matching deeply refined paraffinic lubricating oil components with functional additives, includes the following components: 95-98 wt% deeply refined paraffinic base oil; 0.1-0.5 wt% phenolic antioxidant, which is at least one of high-performance liquid phenol, liquid-shielded phenolic antioxidant, thiophenol-type high-efficiency antioxidant, or high molecular weight phenolic antioxidant; 0.3-2.0 wt% amine antioxidant, which is a blend of diphenylamine antioxidant and aromatic secondary amine antioxidant; and 0.01-0.05 wt% demulsifier, which is an ethylene oxide / propylene oxide block copolymer. Polyether; rust inhibitor 0.04-0.10 wt%, an inorganic carboxylic acid compound; metal deactivator 0.05-0.10 wt%, at least one of 2,5-bis(tert-dodecyl dithio)-1,3,4-thiadiazole and 2,5-bis(alkyl dithio)-1,3,4-thiadiazole derivatives; extreme pressure anti-wear agent 0.5-1.0 wt%, at least one of triphenyl thiophosphate and tricresyl phosphate; pour point depressant 0.01-0.03 wt%, polymethyl methacrylate; antifoaming agent 0.001-0.003 wt%, a complex of silicone and non-silicone antifoaming agents.

2. The ultra-long life gas turbine lubricating oil according to claim 1 includes a lubricating oil preparation method: adding antioxidant, demulsifier, rust inhibitor, metal deactivator, extreme pressure anti-wear agent, pour point depressant and base oil in sequence to a container, heating to 50-60℃, stirring and mixing evenly, continuing to add antifoaming agent, maintaining temperature and stirring evenly, and then filtering. While ensuring air release and anti-foaming capabilities, the oil's oxidation resistance and oil-water separation capabilities have been improved, achieving a result of ≥3500 min under rotating oxygen bomb conditions at 150℃ and a demulsification result of ≤15 min, thereby improving the product's service life in gas turbines and gas-steam combined cycle equipment.

3. The method for preparing lubricating oil according to claim 2, characterized in that: The antioxidants described above have a synergistic effect when used simultaneously with amine and phenolic antioxidants, which have different antioxidant activities. AH is a highly sterically hindered or low-activity antioxidant, while BH is a low-sterically hindered or highly active antioxidant. When it reacts with peroxide free radicals, BH reacts more readily. The highly active antioxidant oxygen agent can effectively capture oxidative free radicals or peroxide free radicals. At this time, the low-activity antioxidant can donate hydrogen atoms, allowing the highly active antioxidant to regenerate and maintain long-term antioxidant efficiency.

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