CN114369492A

CN114369492A - Screw type air compressor oil composition and air compressor oil

Info

Publication number: CN114369492A
Application number: CN202210074859.1A
Authority: CN
Inventors: 王春耕; 王春勇
Original assignee: Beijing Shengxin Hexie Lubricating Grease Co ltd
Current assignee: Beijing Shengxin Hexie Lubricating Grease Co ltd
Priority date: 2022-01-21
Filing date: 2022-01-21
Publication date: 2022-04-19
Anticipated expiration: 2042-01-21
Also published as: CN114369492B

Abstract

The application relates to the field of lubricating oil preparation, and particularly discloses a screw air compressor oil composition and a screw air compressor oil. The screw air compressor oil composition comprises trimethylolpropane oleate, pentaerythritol oleate, polypropylene glycol, polyethylene glycol and alkyl diphenyl ether, wherein the weight ratio of the polypropylene glycol to the polyethylene glycol is (20-30) to (10-20). The screw air compressor oil composition is used for preparing screw air compressor oil. The screw air compressor oil has a good viscosity index, the viscosity index is over 152, the service cycle is over 8000h, and the degradation rate is over 75%; further, the screw air compressor oil can be applied to other compressors, such as compressed natural gas.

Description

Screw type air compressor oil composition and air compressor oil

Technical Field

The application relates to the field of lubricating oil preparation, in particular to a screw air compressor oil composition and air compressor oil.

Background

In the current market for air compressors, screw air compressors are becoming the mainstream compressors, and oil-injected screw compressors are the most widely used ones of screw air compressors. The working principle of oil-injected screw compressors is that when the rotor rotates, the rotor grooves are closed by the casing wall, forming compression chambers. When the rotor groove is closed, compressor oil is sprayed into the compression chamber. When the rotor rotates to compress the oil and gas of the compressor, the volume of the compression chamber is reduced continuously to compress the oil-gas mixture to the exhaust port. When the compression chamber passes through the exhaust port, the oil-gas mixture is discharged from the compressor, completing a suction-compression-exhaust process. The compressor oil plays the role of sealing, cooling and lubricating in the oil-injection screw compressor. Therefore, the compressor oil has important significance for the operation of the screw air compressor.

At present, compressor oils are mainly classified into two types, one is mineral base oil, and the other is synthetic base oil. Mineral base oils are currently used compressor oils and are favored by most users due to their low cost, 12-15 yuan/kg. However, the service life of the mineral base oil is short, and the service life is generally 2000-3000 h. Meanwhile, the mineral base oil has poor heat dissipation effect, easily causes the problem of high temperature of the screw compressor, and needs to be stopped for heat dissipation treatment, thereby bringing certain economic loss to users. In addition, the used mineral base oil has a problem of environmental pollution.

The synthetic base oil mainly comprises Polyalphaolefin (PAO) base oil and ester base oil. Although the service cycle of the synthetic base oil can be prolonged, the service cycle is generally 4000-. However, the synthetic base oils are more expensive than the mineral base oils, 30-35 yuan/kg.

Disclosure of Invention

In order to improve the service cycle of compressor oil and give consideration to economic benefits and environmental protection, the application provides a screw air compressor oil composition and air compressor oil.

In a first aspect, the present application provides a screw air compressor oil composition. The screw air compressor oil composition comprises trimethylolpropane oleate, pentaerythritol oleate, polypropylene glycol, polyethylene glycol and alkyl diphenyl ether, wherein the weight ratio of the polypropylene glycol to the polyethylene glycol is (20-30) to (10-20).

In the application, the screw air compressor oil composition takes trimethylolpropane oleate and pentaerythritol oleate as main raw materials. Trimethylolpropane oleate is an esterified product of trimethylolpropane and oleic acid, and pentaerythritol oleate is an esterified product of pentaerythritol and oleic acid. Trimethylolpropane oleate and pentaerythritol oleate have good lubricity, heat resistance and flame resistance, and have high viscosity index and are not easy to volatilize.

In related research reports, alkyl diphenyl ether is added into the screw air compressor oil composition. The alkyl diphenyl ether can improve the oxidation stability of the screw air compressor oil, and particularly under the high-temperature condition, the screw air compressor oil has small evaporation amount and small viscosity change when in use. Generally, the screw air compressor oil composition is 100 wt%, the trimethylolpropane oleate is 15-25%, the pentaerythritol oleate is 20-30%, and the alkyl diphenyl ether is 5-15%.

This application adds polypropylene glycol and polyethylene glycol to screw air compressor machine oil in, can improve screw air compressor machine oil self performance, prolongs screw air compressor machine oil's life cycle. In addition, the addition of the polypropylene glycol and the polyethylene glycol can improve the degradation rate of the screw air compressor oil and reduce the pollution to the environment. The screw air compressor oil prepared by the application can also be applied to other compressors, such as compressed natural gas.

When polypropylene glycol and polyethylene glycol are mixed according to the proportion of (20-30) to (10-20), the viscosity index and the flash point of the screw type air compressor oil can be improved, and the pour point of the screw type air compressor oil can be reduced. The screw air compressor oil has a pour point below-33 ℃, a viscosity index above 152 and a flash point above 235 ℃. The heat dissipation performance of the screw air compressor oil is improved, the service cycle is more than 8000h, the number of times of machine halt oil change is reduced, and the production cost is further saved. In addition, the degradation rate of the screw air compressor oil is over 75 percent, and the pollution to the environment can be reduced.

When polypropylene glycol or polyethylene glycol is added into the screw type air compressor oil, the viscosity index and the flash point of the screw type air compressor oil are reduced, the pour point is improved, and the service life and the degradation rate of the screw type air compressor oil are further reduced.

Preferably, the weight ratio of the polypropylene glycol to the polyethylene glycol is (22-26): (14-18).

The polypropylene glycol and the polyethylene glycol are added on the basis of trimethylolpropane oleate, pentaerythritol oleate and alkyl diphenyl ether. With the gradual increase of the adding proportion of the polypropylene glycol and the polyethylene glycol, the viscosity index and the flash point of the screw air compressor oil are increased firstly and then reduced, and the pour point is reduced firstly and then increased. The service cycle and the degradation rate of the screw air compressor oil are increased and then reduced.

When the weight ratio of the polypropylene glycol to the polyethylene glycol is (22-26): (14-18), the pour point of the screw air compressor oil is below-36 ℃, the viscosity index is above 155, and the flash point is above 238 ℃. The service cycle of the screw air compressor oil is more than 8700h, and the degradation rate is more than 79%.

In a specific embodiment, the weight ratio of the polypropylene glycol to the polyethylene glycol is 25: 15. The pour point of the screw air compressor oil is-42 ℃, the viscosity index is 160, and the flash point is 243 ℃. The service cycle of the screw air compressor oil is 9500h, and the degradation rate is 82%.

Preferably, the polypropylene glycol has a number average molecular weight of 725-2000.

Polypropylene glycol is a polymer with varying number average molecular weights. The number average molecular weight of polypropylene glycol directly affects the kinematic viscosity of polypropylene glycol. The increase of the number average molecular weight of the polypropylene glycol gradually increases the kinematic viscosity, and influences the performance of screw air compressor oil such as lubricity of the screw air compressor oil to the internal components of the compressor.

According to the screw air compressor oil degradation method, with the gradual increase of the number average molecular weight of the polypropylene glycol, the flash point and the viscosity index of the screw air compressor oil can be improved, the pour point is reduced, the service life of the screw air compressor oil is prolonged, and the degradation rate is improved. When the number average molecular weight of the polypropylene glycol reaches 1000, the flash point and the viscosity index of the screw type air compressor oil gradually decrease and the pour point gradually increases along with the gradual increase of the number average molecular weight of the polypropylene glycol. The service life and the degradation rate of the screw air compressor oil are gradually reduced. Illustratively, the polypropylene glycol has a number average molecular weight of 725, 1500, 2000.

In a specific embodiment, the polypropylene glycol has the number average molecular weight of 1000, the service life of the screw air compressor oil is above 9300h, and the degradation rate is above 82%.

Preferably, the number average molecular weight of the polyethylene glycol is 400-1000.

Polyethylene glycol and polypropylene glycol are also polymers having different number average molecular weights. The number average molecular weight of polyethylene glycol also affects the performance of screw air compressor oil. In the application, when the number average molecular weight of the polyethylene glycol is lower than 400 or higher than 1000, the flash point and the viscosity index of the screw air compressor oil can be improved, and the pour point is reduced. However, the performance of screw air compressor oil is slightly improved. Illustratively, the polyethylene glycol has a number average molecular weight of 400, 800, 1000.

In a specific embodiment, the polyethylene glycol has a number average molecular weight of 600, the screw air compressor oil has a service life of 8300h or more, and the degradation rate is 78% or more.

Preferably, the screw air compressor oil composition further comprises a functional additive.

In the application, the functional additive is added into the screw air compressor oil, so that the self performance and the service performance of the screw air compressor oil are further improved. The functional additives comprise pour point depressant, antioxidant, corrosion inhibitor, detergent, friction reducer, demulsifier, defoaming agent and antirust agent.

In the application, the pour point depressant is polymethacrylate and accounts for 0.2 to 1.0 weight percent of the total weight of the screw air compressor oil composition. The antioxidant is poly dihydroxy-trimethyl quinoline, and accounts for 0.5-2.0 wt% of the total weight of the screw air compressor oil composition. The corrosion inhibitor is barium dinonyl naphthalene sulfonate, and accounts for 0.5-2.0 wt% of the total weight of the screw air compressor oil. The detergent is a boronized ashless detergent, and accounts for 0.1-5.0 wt% of the total weight of the screw type air compressor oil. The friction reducer is a mixture of thiadiazole derivatives and molybdenum thiocarbamate, and accounts for 0.1-1.0 wt% of the total screw air compressor oil composition. The demulsifier accounts for 0.1-0.6 wt% of the total weight of the screw air compressor oil composition. The defoaming agent is methyl silicone oil and accounts for 0.1-0.6 wt% of the total weight of the screw air compressor oil composition. The antirust agent is calcium petroleum sulfonate and accounts for 0.1-1.0 wt% of the total weight of the screw air compressor oil composition.

In a second aspect, the present application provides a screw air compressor oil. The screw air compressor oil is prepared from the screw air compressor oil composition.

Preferably, the service cycle of the screw air compressor oil is more than 8000h, and the oil degradation rate is more than 75%.

The screw air compressor oil composition can be used for preparing screw air compressor oil, so that the service cycle of the screw air compressor oil can be prolonged, and the degradation rate can be improved. The service cycle of the screw air compressor oil is more than 8000h, and the degradation rate is more than 75%. In addition, the used screw air compressor oil can be applied to other compressors. In the application, the viscosity index of the screw air compressor oil is above 152, the pour point is below-33 ℃, and the flash point is above 235 ℃.

In summary, the present application has the following beneficial effects:

1. according to the screw air compressor oil, ester base oil is used as a main body, polypropylene glycol, polyethylene glycol and alkyl diphenyl ether are added, through mutual matching of the components, the service cycle of the screw air compressor oil is over 8000h, and the degradation rate is over 75%;

2. the weight ratio of polypropylene glycol to polyethylene glycol is preferably 25:15, and the screw air compressor oil has high viscosity index, high flash point and low pour point;

3. the number average molecular weight of polypropylene glycol is preferably 1000, the number average molecular weight of polyethylene glycol is 600, the pour point of the screw air compressor oil is-48 ℃, the viscosity index is 167, the flash point is 255 ℃, the service cycle is 9900h, and the degradation rate is 85%.

Detailed Description

The present application will be described in further detail with reference to examples and comparative examples.

Raw materials

The components used in this application are all commercially available and some of the component sources are shown in table 1.

TABLE 1 sources of Components

Components	Source (manufacturer)
		Trimethylolpropane oleate	Nantong Jiuzze chemical Co Ltd
Pentaerythritol oleate	Nantong Jiuzze chemical Co Ltd
		Polypropylene glycol	Nantong Jiuzze chemical Co Ltd
Polyethylene glycol	Nantong Jiuzze chemical Co Ltd
		Alkyl diphenyl ether	SHANGHAI NACO LUBRICATION Co.,Ltd.
Pour point depressant	EVONIK SPECIALTY CHEMICALS (SHANGHAI) Co.,Ltd.

Examples

Example 1

20kg of trimethylolpropane oleate, 30kg of pentaerythritol oleate, 30kg of polypropylene glycol, 10kg of polyethylene glycol and 10kg of alkyl diphenyl ether are mixed to prepare the screw air compressor oil.

Wherein the number average molecular weight of the polypropylene glycol is 725, and the number average molecular weight of the polyethylene glycol is 600.

The screw air compressor oil is added with a functional additive, 0.5kg of pour point depressant (accounting for 0.5 wt% of the total weight of the screw air compressor oil). 1kg of antioxidant (1.0 wt% of the total screw air compressor oil). 1kg of corrosion inhibitor (1 wt% of the total screw air compressor oil). 1kg of detergent (1 wt% of screw air compressor oil). 1kg of friction reducer (1 wt% of the total screw air compressor oil) and 0.6kg of demulsifier (0.6 wt% of the total screw air compressor oil). 0.6kg of defoaming agent (0.6 wt% of the total screw air compressor oil). 0.5kg of rust inhibitor (0.5 wt% of the total screw air compressor oil).

The differences between examples 2 to 12 and example 1 are shown in Table 2.

Table 2 parameters distinguishing examples 2-12 from example 1

In Table 2, "-" indicates that the amount added was 0 kg.

Comparative example 6

The current synthetic base oil is PAO 8. The PAO8 is a chemical technology company of Changsha Jianghong.

Comparative example 7

The current mineral-based lubricating oil is 150 SN. The 150SN is Hongtai petrochemical company, Inc. of Maoming.

Performance test

Detecting one: screw air compressor oil base performance detection

The basic performance tests of the screw air compressor oil of the examples 1 to 12 and the comparative examples 1 to 7 mainly comprise viscosity index, pour point and flash point.

The viscosity index was determined according to the method described in (GB/T2541-1981) Takara Shuzo (Takara Shuzo) for viscosity indices of Petroleum products.

Pour point was measured according to (GB/T3535-2006) Petroleum products pour point determination.

The flash point was measured according to (GB/T3536 & 2008) determination of petroleum products, flash point and ignition point, Cleveland open cup method.

Specific basic test results are shown in table 3.

TABLE 3 basic test results for screw air compressor oil

And (2) detecting: screw air compressor oil usage detection

The screw air compressor oils of examples 1-12 and comparative examples 1-7 were used to test the life cycle and to test the degradation rate of the screw air compressor oil. 19 screw air compressors are selected for testing, the motor power of the screw air compressors is 22KW, the rotating speed is 2940r/min, and the volume flow is 3.5m³Permin, the oil loading for one time is 18 kg. Specific detection results are shown in table 4.

TABLE 4 screw air compressor oil usage test results

Categories	Period of use/hour	Percent of degradation/%)
			Example 1	8400	78
Example 2	9000	80
			Example 3	9500	82
Example 4	8700	79
			Example 5	8000	75
Example 6	9900	85
			Example 7	9200	81
Example 8	9800	85
			Example 9	9600	82
Example 10	8300	78
			Example 11	8800	80
Examples12	9300	82
			Comparative example 1	7200	65
Comparative example 2	7400	68
			Comparative example 3	7800	73
Comparative example 4	7700	70
			Comparative example 5	7200	60
Comparative example 6	6200	15
			Comparative example 7	2100	10

By combining examples 1 to 5 and comparative examples 1 to 5 and combining tables 3 and 4, it can be seen that the viscosity index of the screw air compressor oil can be increased to be over 152 by adding polypropylene glycol and polyethylene glycol into the screw air compressor oil composition and adjusting the adding proportion of the polypropylene glycol and the polyethylene glycol.

And adding the polypropylene glycol and the polyethylene glycol into a mixture consisting of trimethylolpropane oleate, pentaerythritol oleate and alkyl diphenyl ether, and mixing to obtain the screw air compressor oil. The service cycle of the screw air compressor oil is more than 8000h, and the degradation rate is more than 75%.

In particular, in example 3, the adding ratio of the polypropylene glycol to the polyethylene glycol is 25:15, the viscosity index of the screw air compressor oil is 160, the service cycle is 9500h, and the degradation rate is 82%.

Combining examples 3, 6, 7, 10 and 11 and combining tables 3 and 4, it can be seen that the viscosity index, the service life and the degradation rate of the screw air compressor oil increase first and then decrease as the number average molecular weight of the polypropylene glycol increases gradually when the number average molecular weight of the polyethylene glycol is constant. When the number average molecular weight of the polypropylene glycol is 1000, the screw air compressor oil has higher viscosity index, service cycle and degradation rate. The screw air compressor oil has the viscosity index of 167, the service cycle of 9900h and the degradation rate of 85 percent.

Combining examples 5, 8, 9 and 12 and combining tables 3 and 4, it can be seen that the viscosity index, the service life and the degradation rate of the screw air compressor oil gradually increase with the gradually increasing number average molecular weight of the polyethylene glycol when the number average molecular weight of the polypropylene glycol is constant. However, when the number average molecular weight of the polyethylene glycol reaches 600, the viscosity index, the service life and the degradation rate of the screw air compressor oil are gradually reduced.

As can be seen by combining examples 1 to 12 and comparative examples 6 and 7, and by combining table 4, the screw air compressor oil prepared by the present application has a service life 1.29 times or more as long as that of the PAO8 and 3.81 times or more as long as that of the 150SN, as compared with the conventional synthetic base oil PAO8 and mineral-based lubricating oil 150 SN.

In particular, the screw air compressor oil prepared from example 6 used 1.60 times the PAO8 and 4.71 times the 150 SN.

And (3) detection: economic calculation

The use cases of example 5, example 6, comparative example 6 and comparative example 7 were calculated by combining the test results of test one and test two. The specific calculation results are shown in table 5.

In table 5, unit price refers to average price.

The total price is the unit price X for one-time oil loading (18 kg).

The economy refers to the price of screw air compressor oil per hour, and the economy is the total price/service cycle.

TABLE 5 economic calculation results

Categories	Period of use/h	Unit price per kg	Total price/yuan	Economic factor/h
					Example 5	8000	68	1224	0.1555
Example 6	9900	68	1224	0.1236
					Comparative example 6	6200	51	918	0.1481
Comparative example 7	2100	15	270	0.1286

Combining examples 5, 6 and comparative examples 6, 7 and combining table 5, it can be seen that the unit price of examples 5 and 6 is higher than that of comparative examples 6 and 7. From the economical point of view, example 5 is larger than comparative example 6, and comparative example 6 is larger than comparative example 7. However, the working cycle of the embodiment 5 and the embodiment 6 is long, the number of times of stopping and oil changing can be reduced, and the cost is saved.

The present embodiment is only for explaining the present application, and it is not limited to the present application, and those skilled in the art can make modifications of the present embodiment without inventive contribution as needed after reading the present specification, but all of them are protected by patent law within the scope of the claims of the present application.

Claims

1. The screw air compressor oil composition is characterized by comprising trimethylolpropane oleate, pentaerythritol oleate, polypropylene glycol, polyethylene glycol, alkyl diphenyl ether,

wherein the weight ratio of the polypropylene glycol to the polyethylene glycol is (20-30): (10-20).

2. The screw air compressor oil composition of claim 1, wherein the weight ratio of the polypropylene glycol to the polyethylene glycol is (22-26): (14-18).

3. The screw air compressor oil composition of claim 2, the weight ratio of the polypropylene glycol to the polyethylene glycol being 25: 15.

4. The screw air compressor oil composition of any one of claims 1-3, wherein the polypropylene glycol has a number average molecular weight of 725-2000.

5. The screw air compressor oil composition of claim 4, the polypropylene glycol having a number average molecular weight of 1000.

6. The screw air compressor oil composition according to any one of claims 1-3, wherein the polyethylene glycol has a number average molecular weight of 400-1000.

7. The screw air compressor oil composition of claim 6, the polyethylene glycol having a number average molecular weight of 600.

8. A screw air compressor oil prepared from the screw air compressor oil composition according to any one of claims 1 to 7.

9. The screw air compressor oil of claim 8, wherein the service cycle of the air compressor oil is more than 8000h, and the oil degradation rate is more than 75%.