JP2015045323A - Oil-cooled air compressor and control method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve performance of an oil-cooled air compressor, such as delivery air quantity, energy-saving performance and temperature deterioration prevention of lubricant.SOLUTION: An oil-cooled air compressor 1 includes a compressor body 2, an oil separation recovery device 3, an oil cooler 4, and an oil/moisture separation device 5. The oil reservoir of the oil separation recovery device 3 is connected to a suction port 2c of the compressor body 2 through a first oil supply flow passage 7. Lubricant supplied to the compressor body 2 is cooled so that the temperature of compressed air discharged from a discharge port 2d of the compressor body 2 becomes an oil supply temperature equal to or less than a dew point. The oil/moisture separation device 5 is provided in a discharge flow passage 6.

Description

  The present invention relates to an oil-cooled air compressor and a control method thereof.

  In the oil-cooled air compressor, lubricating oil is mixed in the air compressed by the compressor body in order to lubricate the compressor body. The compressed air discharged from the compressor main body is sent to the oil separator / collector and separated into compressed air and lubricating oil. In an oil-cooled air compressor, the temperature of oil injection to the rotor chamber is set to 45 ° C to 55 ° C, and the discharge temperature is reduced to the temperature at which drain water is deposited (the temperature below the dew point) in the oil separator / collector. It is known as a means for improving performance by increasing the amount of air. However, the drain water deposited in the oil separator / recovery unit causes the performance of the lubricating oil to deteriorate and shorten the service life. Therefore, it is necessary to drain the drain water accumulated in the oil separator / recovery unit (drain removal operation). It becomes.

  In the current oil-cooled air compressor, drain water accumulation in the oil separation and recovery unit is intentionally adjusted to a temperature above the dew point (for example, about 80 ° C.) by evaporating the water. Is preventing. For example, in Patent Document 1, by supplying lubricating oil not through an oil cooler to the discharge port side of the rotor chamber of the compressor main body, the discharge temperature is set to a temperature at which the inside of the oil separation and recovery device is equal to or higher than the dew point. Is disclosed. Further, in Patent Document 2, the temperature of the lubricating oil supplied to the compressor body is adjusted by controlling the flow rate ratio of the lubricating oil passing through the oil cooler to the lubricating oil without going through the oil cooler, and thereby the oil separator / recoverer It is disclosed that the discharge temperature is adjusted so that the inside becomes the dew point or higher.

  However, Patent Document 1 does not take into consideration that the discharge temperature is lower than the temperature at which drain water is precipitated in the oil separation and recovery device. Moreover, in patent document 2, it is necessary to maintain the temperature of an oil separation collection | recovery device at high temperature, and it is difficult to reduce discharge temperature. Furthermore, in Patent Document 2, the lubricating oil is kept at a high temperature during the operation of the oil-cooled air compressor, which leads to deterioration of the lubricating oil. As described above, conventional oil-cooled air compressors including those disclosed in Patent Documents 1 and 2 have room for further performance improvement.

Japanese Unexamined Patent Publication No. 7-35067 JP 2012-112268 A

  An object of the present invention is to improve the performance of an oil-cooled air compressor, such as the amount of discharged air, energy saving, and prevention of temperature deterioration of lubricating oil.

  A first aspect of the present invention is an oil-cooled compressor main body that compresses and discharges sucked air, and an oil separation and recovery device that separates and recovers lubricating oil from the compressed air discharged from the compressor main body A first oil supply passage connecting the oil separator and the suction side of the compressor body, and the first oil supply passage, wherein the air is below a dew point in the compressor body. An oil-cooled air compressor comprising an oil cooler that cools the lubricating oil to an oil supply temperature. Thereby, the temperature of the compressed air discharged from the compressor body (hereinafter sometimes referred to as a discharge temperature) can be set to a dew point or lower.

  By setting the discharge temperature of the compressor main body to a dew point or lower, it is possible to improve performance by increasing the amount of discharged air, and energy saving is improved. Further, since the discharge temperature is lower than the dew point and not high, the temperature deterioration of the lubricating oil can be prevented.

  Specifically, the oil-cooled air compressor further includes an oil / water separator that separates moisture generated in the compressor body during air compression from the lubricating oil outside the compressor body.

  Moisture in the compressed air is precipitated by setting the discharge temperature below the dew point. Moisture mixed in the lubricating oil causes deterioration of the lubricating oil. By providing the oil / water separator, it is possible to prevent water from being mixed into the lubricating oil.

  The oil / water separator may be a coalescer oil / water separator.

  The oil / water separator may be a gravity water tank type oil / water separator.

  The oil / water separator includes an open channel that connects a space above the liquid level in the oil separator / collector and a space lower in pressure than the space, an electromagnetic valve provided in the open channel, and the lubricating oil. The electromagnetic valve is opened in accordance with at least one of the amount of water contained in the compressor and the discharge pressure of the compressor body, and the compressed air in the space in the oil separation and recovery device is discharged into the low pressure space. And a moisture release control unit.

  The oil cooler may be capable of adjusting a supply temperature of the lubricating oil to the compressor body. In this case, the oil / water separator is configured such that the temperature of the lubricating oil in the oil separator / collector is temporarily dew point in accordance with at least one of the amount of water contained in the lubricating oil and the discharge pressure of the compressor body. The oil cooler may be provided to control the oil cooler so that the oil supply temperature exceeds the oil supply temperature. The oil / water separator rotates at a temperature at which the temperature of the lubricating oil in the oil separator / collector temporarily exceeds the dew point according to at least one of the amount of water contained in the lubricating oil and the discharge pressure of the compressor body. You may provide the temperature rising control part which controls the drive device of the said compressor main body so that it may become number.

  The second aspect of the present invention is an oil-cooled compressor main body that compresses and discharges sucked air, and an oil separation and recovery device that separates and recovers lubricating oil from the compressed air discharged from the compressor main body. And a control method of an oil-cooled air compressor comprising an oil supply passage connecting the oil separation and recovery device and a suction side of the compressor body, and an oil cooler provided in the oil supply passage, The lubricating oil is supplied by the oil cooler so that the air is below the dew point in the compressor body or the discharge temperature, which is the temperature of the compressed air discharged from the compressor body, is below the dew point. Provided is a method for controlling a cooling oil-cooled air compressor.

  The oil cooler temporarily adjusts the temperature of the lubricating oil in the oil separator / collector above the dew point according to at least one of the amount of water contained in the lubricating oil and the discharge pressure of the compressor body. The lubricating oil may be cooled.

  By setting the discharge temperature of the compressor main body to a dew point or lower, it is possible to improve performance by increasing the amount of discharged air, and energy saving is improved. Further, since the discharge temperature is lower than the dew point and not high, the temperature deterioration of the lubricating oil can be prevented.

The schematic diagram which shows the whole structure of the oil-cooled air compressor which concerns on 1st Embodiment of this invention. The schematic diagram which shows the whole structure of the oil-cooled air compressor which concerns on 2nd Embodiment of this invention. The schematic diagram which shows the whole structure of the oil-cooled air compressor which concerns on 3rd Embodiment of this invention. The schematic diagram which shows the whole structure of the oil-cooled air compressor which concerns on 4th Embodiment of this invention. The schematic diagram which shows the whole structure of the oil-cooled air compressor which concerns on 5th Embodiment of this invention. The schematic diagram which shows the whole structure of the oil-cooled air compressor which concerns on 6th Embodiment of this invention. The schematic diagram which shows the whole structure of the oil-cooled air compressor which concerns on 7th Embodiment of this invention. The schematic diagram which shows the whole structure of the oil-cooled air compressor which concerns on 8th Embodiment of this invention. The schematic diagram which shows the whole structure of the oil-cooled air compressor which concerns on 9th Embodiment of this invention. The schematic diagram which shows the whole structure of the oil-cooled air compressor which concerns on 10th Embodiment of this invention. The schematic diagram which shows the whole structure of the oil-cooled air compressor which concerns on 11th Embodiment of this invention. The schematic diagram which shows the whole structure of the oil-cooled air compressor which concerns on 12th Embodiment of this invention. The schematic diagram which shows the whole structure of the oil-cooled air compressor which concerns on 13th Embodiment of this invention. The schematic diagram which shows the whole structure of the oil-cooled air compressor which concerns on 14th Embodiment of this invention. The schematic diagram which shows the whole structure of the oil-cooled air compressor which concerns on 15th Embodiment of this invention. The schematic diagram which shows the whole structure of the oil-cooled air compressor which concerns on 16th Embodiment of this invention. The schematic diagram which shows the whole structure of the oil-cooled air compressor which concerns on 17th Embodiment of this invention. The schematic diagram which shows the whole structure of the oil-cooled air compressor which concerns on 18th Embodiment of this invention. The schematic diagram which shows the whole structure of the oil-cooled air compressor which concerns on 19th Embodiment of this invention. The schematic diagram which shows the whole structure of the oil-cooled air compressor which concerns on 20th Embodiment of this invention. The schematic diagram which shows the whole structure of the oil-cooled air compressor which concerns on 21st Embodiment of this invention. The schematic diagram which shows the whole structure of the oil-cooled air compressor which concerns on 22nd Embodiment of this invention. The schematic diagram which shows the whole structure of the oil-cooled air compressor which concerns on 23rd Embodiment of this invention. The schematic diagram which shows the whole structure of the oil-cooled air compressor which concerns on 24th Embodiment of this invention. The schematic diagram which shows the whole structure of the oil-cooled air compressor which concerns on 25th Embodiment of this invention. The figure which shows the whole structure of the oil-cooled air compressor which concerns on 26th Embodiment of this invention. The typical fragmentary sectional view of a compressor main body.

(First embodiment)
FIG. 1 shows an oil-cooled air compressor 1 according to a first embodiment of the present invention. The oil-cooled air compressor 1 includes a compressor main body 2 that is an oil-cooled screw compressor, an oil separator / recoverer 3, an oil cooler 4, and an oil / water separator 5 (in this embodiment, a coalescer-type oil / water separator). Device).

  Referring also to FIG. 27, the compressor body 2 includes a pair of male and female rotors (screw rotors) 2b and 2b (rotated by a driving device not shown in the present embodiment) housed in the rotor chamber 2a. Prepare. Further, a suction port 2c and a discharge port 2d communicating with the rotor chamber 2a are provided.

  A discharge port 2 d of the compressor body 2 is connected to the oil separation / recovery device 3 through a discharge flow path 6. In the present embodiment, the oil / water separator 5 is provided in the discharge flow path 6.

  The oil sump at the bottom of the oil separator / recovery unit 3 is connected to the suction port 2 c of the compressor body 2 via the first oil supply passage 7. In FIG. 27, the connection position of the suction port 2c of the first oil supply passage 7, that is, the oil supply position, is conceptually indicated by reference numeral P1. An oil cooler 4 is provided in the first oil supply passage 7.

  In the rotor chamber 2a of the compressor body 2, the space formed by the tooth spaces of the rotors 2b and 2b and the inner wall of the rotor chamber 2a is reduced as the rotor 2b and 2b rotate, and the volume is reduced thereby. The air sucked from the port 2c is compressed and discharged from the discharge port 2d. The compressed air discharged from the discharge port 2 d flows into the oil separation / recovery device 3 through the discharge flow path 6. In the oil separator / collector 3, the lubricating oil is separated from the compressed air and temporarily stored in a lower oil sump. The compressed air from which the lubricating oil has been separated is sent from the outlet 3a of the oil separator / recoverer 3 to the downstream side (not shown).

  The lubricating oil stored in the oil sump of the oil separator / recovery unit 3 passes through the first oil supply passage 7 due to the differential pressure between the oil separation / recovery unit 3 and the compressor main body 2 (suction port 2c). It flows to (oil supply position P1 in FIG. 27). The lubricating oil flowing to the compressor body 2 through the first oil supply passage 7 is cooled when passing through the oil cooler 4.

  The oil cooler 4 cools the lubricating oil to a temperature at which the air sucked from the suction port 2 c is equal to or lower than the dew point in the compressor body 2. In other words, the oil cooler 4 is configured so that the temperature of the compressed air (discharge temperature) discharged from the discharge port 2d of the compressor body 2 becomes the oil supply temperature at which the dew point (condensation temperature of water) is equal to or lower. The lubricating oil supplied to 2 is cooled. The air sucked from the suction port 2c becomes the dew point or less in the compressor body 2, and the moisture in the compressed air precipitates in the compressor body 2, so that the performance can be improved by increasing the amount of discharged air. , Energy saving is improved. Further, since the discharge temperature is lower than the dew point and not high, the temperature deterioration of the lubricating oil can be prevented. The cooling capacity of the oil cooler 4 is set so that the discharge temperature is equal to or lower than the dew point according to the specifications of the compressor body 2 and the like.

  By setting the discharge temperature below the dew point, the compressed air discharged from the discharge port 2d of the compressor body 2 contains precipitated water. Moisture mixed in the lubricating oil causes deterioration of the lubricating oil. However, since the oil / water separator 5 is provided in the discharge flow path 6, moisture is separated from the lubricating oil contained in the compressed air flowing from the compressor body 2 to the oil separator / collector 3. That is, by providing the oil / water separator 5 to separate the lubricating oil and the water, it is possible to prevent the deterioration of the lubricating oil due to the mixed water. Further, in the present embodiment, since the oil / water separator 5 is provided in the discharge flow path 6, it is possible to prevent water from being deposited in the oil separator / collector 3 and accumulating as drain water in the oil reservoir.

  As described above, in the oil-cooled air compressor of the present embodiment, the compressor main body 2 is improved in performance and prevention of temperature deterioration of the lubricating oil by setting the discharge temperature of the compressor main body 2 below the dew point. By providing the oil / water separator 5, the mixing of water in the lubricating oil and the deterioration of the lubricating oil due to the discharge temperature being set to the dew point or lower is prevented. Further, since the compressed air is already below the dew point when it is discharged from the discharge port 2d of the compressor body 2, the compressed air cooler or the compressed air is placed at a position downstream of the compressed air flow. When installing a dryer for removing moisture, the cooling capacity can be reduced.

  In order to more easily and reliably separate water from the lubricating oil in the oil / water separator 5, the lubricating oil preferably has hydrophobicity. Further, by using a lubricating oil having a specific gravity lower than that of water, that is, a lubricating oil having a specific gravity difference from that of water, the oil / water separator 5 can more easily and reliably separate water from the lubricating oil. For example, the specific gravity of the lubricating oil is preferably 0.95 or less.

(Second Embodiment)
FIG. 2 shows an oil-cooled air compressor 1 according to the second embodiment of the present invention. The oil cooler 4 cools the lubricating oil to a temperature at which the air sucked from the suction port 2 c is equal to or lower than the dew point in the compressor body 2. In other words, the oil cooler 4 cools the lubricating oil supplied to the compressor main body 2 through the first oil supply passage 7 so that the discharge temperature of the compressor main body 2 becomes the oil supply temperature that is not more than the dew point. An oil / water separation device 5 (in this embodiment, a coalescer type or gravity water tank type oil / water separation device) for separating water from the lubricating oil is provided in the oil separation / recovery unit 3. By providing the oil / water separation device 5 in the oil separation / recovery device 3, compared to the case where the oil separation / recovery device 3 and the oil / water separation device 5 are provided separately, the installation projected area of the oil-cooled air compressor 1 is reduced. Increase can be avoided.

  Other configurations and operations of the second embodiment are the same as those of the first embodiment.

(Third embodiment)
FIG. 3 shows an oil-cooled air compressor 1 according to the third embodiment of the present invention. The oil cooler 4 cools the lubricating oil to a temperature at which the air sucked from the suction port 2 c is equal to or lower than the dew point in the compressor body 2. In other words, the oil cooler 4 cools the lubricating oil supplied to the compressor main body 2 through the first oil supply passage 7 so that the discharge temperature of the compressor main body 2 becomes the oil supply temperature that is not more than the dew point. An oil / water separator 5 (in this embodiment, a coalescer type or gravity water tank type oil / water separator) for separating moisture from the lubricating oil is provided in the first oil supply passage 7. Specifically, the oil / water separator 5 is provided upstream of the oil cooler 4 in the first oil supply passage 7. By providing the oil / water separator 5 in the first oil supply flow path 7, the lubricating oil can be allowed to flow into the oil / water separator 5 without requiring pumping by a pump. Note that the oil / water separator 5 may be provided on the downstream side of the oil cooler 4 in the first oil supply passage 7.

  Other configurations and operations of the third embodiment are the same as those of the first embodiment.

(Fourth embodiment)
FIG. 4 shows an oil-cooled air compressor 1 according to the fourth embodiment of the present invention. The oil cooler 4 cools the lubricating oil to a temperature at which the air sucked from the suction port 2 c is equal to or lower than the dew point in the compressor body 2. In other words, the oil cooler 4 cools the lubricating oil supplied to the compressor main body 2 through the first oil supply passage 7 so that the discharge temperature of the compressor main body 2 becomes the oil supply temperature that is not more than the dew point.

  In the present embodiment, in addition to the first oil supply flow path 7, a second oil supply flow path 8 that connects the oil reservoir of the oil separator / collector 3 and the suction side of the compressor body 2 is provided. The oil supply position to the compressor main body 2 of the 2nd oil supply flow path 8 of this embodiment is the suction inlet 2c, as shown to the code | symbol P1 of FIG. An oil / water separator 5 (in this embodiment, a coalescer type or gravity water tank type oil / water separator) is provided in the second oil supply passage 8. By providing the second oil supply flow path 8 and supplying oil to the suction port 2c, the intake air to the compressor body 2 can be cooled, thereby improving the performance by increasing the amount of discharge air.

  Other configurations and operations of the fourth embodiment are the same as those of the first embodiment.

(Fifth embodiment)
FIG. 5 shows an oil-cooled air compressor 1 according to the fifth embodiment of the present invention. The oil cooler 4 cools the lubricating oil to a temperature at which the air sucked from the suction port 2 c is equal to or lower than the dew point in the compressor body 2. In other words, the oil cooler 4 cools the lubricating oil supplied to the compressor main body 2 through the first oil supply passage 7 so that the discharge temperature of the compressor main body 2 becomes the oil supply temperature that is not more than the dew point.

  In the present embodiment, in addition to the first oil supply flow path 7, a second oil supply flow path 8 that connects the oil reservoir of the oil separator / collector 3 and the suction side of the compressor body 2 is provided. The oil supply position to the compressor main body 2 of the second oil supply passage 8 of the present embodiment is set in a space portion (immediately after closing) of the rotor chamber 2a immediately after the suction port 2c, as indicated by reference numeral P3 in FIG. Has been. An oil / water separator 5 (in this embodiment, a coalescer type or gravity water tank type oil / water separator) is provided in the second oil supply passage 8. By providing the second oil supply passage 8 and supplying oil immediately after the compressor body 2 is closed, the air at the start of compression can be cooled, thereby improving the performance by increasing the amount of discharged air.

  Other configurations and operations of the fifth embodiment are the same as those of the first embodiment.

(Sixth embodiment)
FIG. 6 shows an oil-cooled air compressor 1 according to a sixth embodiment of the present invention. The oil cooler 4 cools the lubricating oil to a temperature at which the air sucked from the suction port 2 c is equal to or lower than the dew point in the compressor body 2. In other words, the oil cooler 4 cools the lubricating oil supplied to the compressor main body 2 through the first oil supply passage 7 so that the discharge temperature of the compressor main body 2 becomes the oil supply temperature that is not more than the dew point.

  In the present embodiment, in addition to the first oil supply flow path 7, a second oil supply flow path 8 that connects the oil reservoir of the oil separator / collector 3 and the suction side of the compressor body 2 is provided. The oil supply position of the second oil supply passage 8 of the present embodiment to the compressor body 2 is set so as to supply oil to the rotors 2b and 2b in the rotor chamber 2a in the compression process, as indicated by reference numeral P2 in FIG. ing. An oil / water separator 5 (in this embodiment, a coalescer type or gravity water tank type oil / water separator) is provided in the second oil supply passage 8. By providing the second oil supply passage 8 and supplying oil to the rotors 2b and 2b, the air heated by the compression can be cooled, thereby improving the performance by increasing the amount of discharged air.

  Other configurations and operations of the sixth embodiment are the same as those of the first embodiment.

(Seventh embodiment)
FIG. 7 shows an oil-cooled air compressor 1 according to a seventh embodiment of the present invention. The oil cooler 4 cools the lubricating oil to a temperature at which the air sucked from the suction port 2 c is equal to or lower than the dew point in the compressor body 2. In other words, the oil cooler 4 cools the lubricating oil supplied to the compressor main body 2 through the first oil supply passage 7 so that the discharge temperature of the compressor main body 2 becomes the oil supply temperature that is not more than the dew point.

  In the present embodiment, in addition to the first oil supply flow path 7, a second oil supply flow path 8 that connects the oil reservoir of the oil separator / collector 3 and the suction side of the compressor body 2 is provided. The oil supply position to the compressor main body 2 of the second oil supply flow path 8 of the present embodiment is set in a space portion (immediately before discharge) immediately before the discharge port 2d of the rotor chamber 2a as indicated by reference numeral P4 in FIG. ing. The second oil supply passage 8 is provided with a pump 10 for pumping the lubricating oil. The second oil supply passage 8 is provided with an oil / water separator 5 (in this embodiment, a coalescer type or gravity water tank type oil / water separator) downstream of the pump 10. By providing the second oil supply passage 8 and supplying oil immediately before the discharge of the compressor body 2, the compressed air after discharge from the discharge port 2 d of the compressor body 2 can be cooled.

  Other configurations and operations of the seventh embodiment are the same as those of the first embodiment.

(Eighth embodiment)
FIG. 8 shows an oil-cooled air compressor 1 according to the eighth embodiment of the present invention. The oil cooler 4 cools the lubricating oil to a temperature at which the air sucked from the suction port 2 c is equal to or lower than the dew point in the compressor body 2. In other words, the oil cooler 4 cools the lubricating oil supplied to the compressor main body 2 through the first oil supply passage 7 so that the discharge temperature of the compressor main body 2 becomes the oil supply temperature that is not more than the dew point.

  In the present embodiment, apart from the first oil supply flow path 7, a return flow path 9 that connects the oil reservoir of the oil separator / collector 3 and the flow path immediately after the discharge port 2 d of the compressor body 2 is provided. Yes. A joining position with respect to the flow path immediately after the discharge port 2d of the return flow path 9 is conceptually indicated by a symbol P5 in FIG. The return flow path 9 is provided with a pump 11 that pumps the lubricating oil from the oil separator / collector 3 toward the joining position P5. The return passage 9 is provided with an oil / water separator 5 (in this embodiment, a coalescer type or gravity water tank type oil / water separator) downstream of the pump 11. By providing the return flow path 9 and supplying oil to the flow path immediately after the discharge port 2d, the compressed air discharged from the discharge port 2d of the compressor body 2 can be cooled.

  Other configurations and operations of the eighth embodiment are the same as those of the first embodiment.

(Ninth embodiment)
FIG. 9 shows an oil-cooled air compressor 1 according to the ninth embodiment of the present invention. The oil cooler 4 cools the lubricating oil to a temperature at which the air sucked from the suction port 2 c is equal to or lower than the dew point in the compressor body 2. In other words, the oil cooler 4 cools the lubricating oil supplied to the compressor main body 2 through the first oil supply passage 7 so that the discharge temperature of the compressor main body 2 becomes the oil supply temperature that is not more than the dew point.

  In the present embodiment, a bypass passage 12 is provided that connects the oil reservoir of the oil separation and recovery device 3 and the first oil supply passage 7 on the downstream side of the oil cooler 4 by bypassing the oil cooler 4. . An oil / water separator 5 (in this embodiment, a coalescer type or gravity water tank type oil / water separator) is provided in the bypass passage 12. Due to the differential pressure between the oil separator / collector 3 and the compressor main body 2 (suction port 2 c), the lubricating oil flows from the oil separator / collector 3 to the junction with the first oil supply passage 7 through the bypass passage 12. . That is, the lubricating oil can be allowed to flow into the oil / water separator 5 without using a pump. In addition, the oil cooler 4 and the oil / water separator 5 that are pressure losses with respect to the flow of the lubricating oil are provided in different flow paths (the former is the first oil supply flow path 7 and the latter is the bypass flow path 12) in parallel. Therefore, the flow resistance of the lubricating oil can be reduced as a whole flow path from the oil separator / collector 3 to the compressor body 2.

  Other configurations and operations of the ninth embodiment are the same as those of the first embodiment.

(10th Embodiment)
FIG. 10 shows an oil-cooled air compressor 1 according to a tenth embodiment of the present invention. The oil cooler 4 cools the lubricating oil to a temperature at which the air sucked from the suction port 2 c is equal to or lower than the dew point in the compressor body 2. In other words, the oil cooler 4 cools the lubricating oil supplied to the compressor main body 2 through the first oil supply passage 7 so that the discharge temperature of the compressor main body 2 becomes the oil supply temperature that is not more than the dew point.

  In the present embodiment, a bypass flow path 12 is provided that branches from the upstream side of the oil cooler 4 of the first oil supply flow path 7 and merges with the first oil supply flow path 7 downstream of the oil cooler 4. It has been. Due to the differential pressure between the oil separator / collector 3 and the compressor body 2, the lubricating oil flows through the bypass flow path 12 and bypasses the oil cooler 4. That is, lubricating oil can be flowed into the oil / water separator 5 (in this embodiment, a coalescer type or gravity water tank type oil / water separator) without using a pump. As in the ninth embodiment, the oil cooler 4 and the oil / water separator 5 are arranged in parallel in different flow paths, so that the flow of the lubricating oil as a whole flow path from the oil separator / collector 3 to the compressor body 2 is achieved. Resistance can be reduced.

  Other configurations and operations of the tenth embodiment are the same as those of the first embodiment.

(Eleventh embodiment)
The oil-cooled air compressor 1 according to the eleventh embodiment of the present invention shown in FIG. 11 is branched from the upstream side of the oil cooler 4 of the first oil supply passage 7 as in the tenth embodiment. A bypass passage 12 that joins the first oil supply passage 7 on the downstream side of the cooler 4 is provided. The bypass channel 12 passes through the bypass channel 12 before and after the oil / water separator 5 (in this embodiment, a coalescer-type or gravity water tank-type oil / water separator) (immediately before the upstream of the oil-water separator 5 and immediately after the downstream) On-off valves 13A and 13B that can block the flow of the lubricating oil are provided. These on-off valves 13A and 13B may be manual or electromagnetic valves. The on-off valves 13A and 13B are normally maintained in an open state. When the on-off valves 13A and 13B are closed, the oil / water separator 5 can be disconnected from the bypass passage 12. By temporarily closing the on-off valves 13A and 13B, the oil / water separator 5 can be maintained even while the oil-cooled air compressor 1 is in operation.

  Other configurations and operations of the eleventh embodiment are the same as those of the first embodiment.

  As shown by the two-dot chain line in FIGS. 4 to 9 and FIGS. 12 to 15 referred to later, the fourth to ninth embodiments and the twelfth to fifteenth embodiments are also implemented before and after the oil-water separator 5. On-off valves 13A and 13B similar to the embodiment may be provided.

(Twelfth embodiment)
FIG. 12 shows an oil-cooled air compressor 1 according to a twelfth embodiment of the present invention. The oil cooler 4 cools the lubricating oil to a temperature at which the air sucked from the suction port 2 c is equal to or lower than the dew point in the compressor body 2. In other words, the oil cooler 4 cools the lubricating oil supplied to the compressor main body 2 through the first oil supply passage 7 so that the discharge temperature of the compressor main body 2 becomes the oil supply temperature that is not more than the dew point.

  In the present embodiment, a circulation passage 15 is provided that returns from the oil reservoir of the oil separation and recovery unit 3 to the oil separation and recovery unit 3 via the pump 14. An oil / water separator 5 (in this embodiment, a coalescer type or gravity water tank type oil / water separator) is provided downstream of the pump 14 in the circulation channel 15. By providing the oil / water separator 5 in the circulation passage 15 of a different system from the first oil supply passage 7, it is possible to avoid the occurrence of pressure loss in the first oil supply passage 7 by providing the oil / water separator 5. .

  Other configurations and operations of the twelfth embodiment are the same as those of the first embodiment.

(13th Embodiment)
In FIG. 13, the oil-cooled air compressor 1 according to the thirteenth embodiment of the present invention supplies oil to the compressor body so that the discharge temperature, which is the temperature of the compressed air discharged from the compressor body 2, is below the dew point. A mechanism for adjusting the temperature (oil supply temperature adjusting mechanism) is provided. This also applies to the 14th and 15th embodiments described later.

  In addition to the first oil supply passage 7, a second oil supply passage 8 that connects the oil reservoir of the oil separator / collector 3 and the suction side of the compressor body 2 (for example, symbol P <b> 3 in FIG. 27) is provided. Yes. An oil / water separator 5 (in this embodiment, a coalescer type or gravity water tank type oil / water separator) is provided in the second oil supply passage 8.

  In the first oil supply passage 7, a three-way valve 16 that functions as a temperature control valve is provided upstream of the oil cooler 4. By this three-way valve 16, the bypass oil supply passage 17 is branched from the first oil supply passage 7. The bypass oil supply passage 17 is connected to the suction side of the compressor body 2 (for example, symbol P3 in FIG. 27).

  The three-way valve 16 includes a state (first state) in which the oil reservoir of the oil separation / recovery unit 3 is communicated with the compressor body 2 through the first oil supply passage 7 and the oil cooler 4, and oil separation / recovery. It is possible to switch to a state (second state) in which the oil reservoir of the compressor 3 is communicated with the compressor body 2 via a bypass oil supply passage 17 that bypasses the oil cooler 4.

  A temperature sensor 18 that directly or indirectly measures the discharge temperature, which is the temperature of the compressed air discharged from the discharge port 2d of the compressor body 2, is provided. In the present embodiment, the temperature sensor 18 is provided in the oil separation / recovery unit 3 and measures the temperature of the oil separation / recovery unit 3 to indirectly measure the discharge temperature. However, the temperature sensor 18 may be disposed at or near the discharge port 2d to directly measure the discharge temperature. Further, the discharge temperature may be indirectly measured by arranging the temperature sensor 18 at a place other than the oil separator / collector 3.

  The controller 19 controls the three-way valve 16 in accordance with the temperature detected by the temperature sensor 18 so that the discharge temperature, which is the temperature of the compressed air discharged from the discharge port 2d of the compressor body 2, is equal to or lower than the dew point. Specifically, if the controller 19 determines that the discharge temperature is equal to or higher than the dew point based on the temperature measured by the temperature sensor 18, the controller 19 sets the three-way valve 16 to the first state. In this first state, the lubricating oil (excluding the flow rate through the second oil supply passage 8) from the oil separator / collector 3 passes through the oil cooler 4 and passes through the first oil supply passage 7. Supplied to the compressor body 2. On the other hand, if the controller 19 determines that the discharge temperature is lower than the dew point based on the temperature measured by the temperature sensor 18, the controller 19 sets the three-way valve 16 to the second state. In this second state, the lubricating oil from the oil separator / recoverer 3 (except for the flow rate through the second oil supply passage 8) is compressed through the bypass oil supply passage 17 without passing through the oil cooler 4. Supplied to the machine body 2.

  The lubricating oil (cooled by the oil cooler 4) supplied to the compressor main body 2 when the three-way valve 16 is in the first state is the compressor main body 2 when the three-way valve 16 is in the second state. The temperature is lower than the lubricating oil supplied to the oil (not cooled by the oil cooler 4). Therefore, the controller 19 switches the three-way valve 16 according to the temperature detected by the temperature sensor 18 to adjust the temperature of the lubricating oil supplied to the compressor body 2, thereby keeping the discharge temperature below the dew point. The controller 19 switches the three-way valve 16 from the second state to the first state when the temperature of the compressed air reaches a first set temperature that is slightly higher than the dew point. Alternatively, the three-way valve 16 may be switched from the first state to the second state when the second set temperature is slightly lower.

  Other configurations and operations of the thirteenth embodiment are the same as those of the first embodiment.

  In addition, as shown with a dashed-two dotted line in FIGS. 1-12, you may provide the three-way valve 16 and the bypass oil supply flow path 17 similar to this embodiment also about 1st-12th Embodiment. In this case, a controller (not shown in these drawings) is a three-way valve in response to a temperature sensor that directly or indirectly measures the discharge temperature, which is the temperature of the compressed air discharged from the discharge port 2d of the compressor body 2. By switching 16, the oil supply temperature to the compressor main body 2 can be adjusted so that the discharge temperature of the compressor main body 2 is lower than the dew point.

(14th Embodiment)
FIG. 14 shows an oil-cooled air compressor 1 according to a fourteenth embodiment of the present invention.

  In addition to the first oil supply passage 7, a second oil supply passage 8 that connects the oil reservoir of the oil separator / collector 3 and the suction side of the compressor body 2 (for example, symbol P <b> 3 in FIG. 27) is provided. Yes. An oil / water separator 5 (in this embodiment, a coalescer type or gravity water tank type oil / water separator) is provided in the second oil supply passage 8.

  The first oil supply passage 7 is provided with an electromagnetic valve 21 as an on-off valve that can be electrically controlled on the upstream side of the oil cooler 4.

  A temperature sensor 18 that directly or indirectly measures the discharge temperature, which is the temperature of the compressed air discharged from the discharge port 2 d of the compressor body 2, is provided in the oil separation and recovery device 3. The arrangement position of the temperature sensor 18 and the temperature to be detected are not limited as described in the thirteenth embodiment.

  The controller 19 controls the electromagnetic valve 21 in accordance with the temperature detected by the temperature sensor 18 so that the discharge temperature is lower than the dew point. Specifically, when the controller 19 determines that the discharge temperature is equal to or higher than the dew point based on the temperature measured by the temperature sensor 18, the controller 19 opens the solenoid valve 21. When the solenoid valve 21 is in the open state, all of the lubricating oil from the oil separator / collector 3 passes through the oil cooler 4 and is supplied to the compressor body 2 through the first oil supply passage 7. On the other hand, if the controller 19 determines that the discharge temperature is lower than the dew point based on the temperature measured by the temperature sensor 18, the controller 19 closes the electromagnetic valve 21. When the solenoid valve 21 is in the closed state, all the lubricating oil from the oil separator / collector 3 is supplied to the compressor body 2 through the second oil supply passage 8 without passing through the oil cooler 4.

  Lubricating oil (cooled by the oil cooler 4) supplied to the compressor body 2 when the solenoid valve 21 is opened is supplied to the compressor body 2 when the solenoid valve 21 is closed. The temperature is lower than that of the lubricating oil (not cooled by the oil cooler 4). Therefore, the controller 19 adjusts the temperature of the lubricating oil supplied to the compressor body 2 by switching the open / close state of the electromagnetic valve 21 according to the temperature detected by the temperature sensor 18, thereby keeping the discharge temperature below the dew point. Can do. The controller 19 switches the solenoid valve 21 from the closed state to the open state when the temperature of the compressed air reaches a first set temperature that is slightly higher than the dew point, and the temperature of the compressed air is slightly lower than the dew point. The electromagnetic valve 21 may be switched from the open state to the closed state when the second set temperature is low.

  In addition, as shown by a broken line in FIG. 14, another electromagnetic valve 121 similar to the electromagnetic valve 21 may be provided in the second oil supply passage 8. In this case, the controller 19 switches the open / close state of the electromagnetic valve 121, contrary to the open / close state of the electromagnetic valve 21.

  Further, as shown in FIGS. 4 to 7 and FIGS. 9 to 11, the same solenoid valve 21 as that of the present embodiment is used for the fourth to seventh embodiments and the ninth to eleventh embodiments. You may provide upstream of the oil cooler 4 of the flow path 7. Among these configurations, in the fourth to seventh embodiments (FIGS. 4 to 7), the lubricating oil from the oil separation / recovery unit 3 is supplied to the first oil supply passage 7 according to the open / close state of the electromagnetic valve 21. (Through the oil cooler 4) or the second oil supply passage 8 (not through the oil cooler 4) is supplied to the compressor body 2. Further, in the ninth to eleventh embodiments (FIGS. 9 to 11), the lubricating oil from the oil separation / recovery unit 3 is supplied to the first oil supply passage 7 (oil cooler) according to the open / close state of the electromagnetic valve 21. 4) or a bypass passage 12 (not through the oil cooler 4) and supplied to the compressor body 2.

  Other configurations and operations of the fourteenth embodiment are the same as those of the first embodiment.

(Fifteenth embodiment)
FIG. 15 shows an oil-cooled air compressor 1 according to the fifteenth embodiment of the present invention.

  In the present embodiment, a bypass flow path 12 is provided that branches from the upstream side of the oil cooler 4 of the first oil supply flow path 7 and merges with the first oil supply flow path 7 downstream of the oil cooler 4. It has been. An oil / water separator 5 (in this embodiment, a coalescer type or gravity water tank type oil / water separator) is provided in the bypass passage 12.

  The first oil supply passage 7 is provided with a three-way valve 22 at a branch position of the bypass passage 12 on the upstream side of the oil cooler 4. The three-way valve 22 has a state (first state) in which the oil reservoir of the oil separation / recovery unit 3 is communicated with the compressor body 2 through the oil cooler 4, and an oil reservoir of the oil separation / recovery unit 3. Can be switched to a state (second state) in which the compressor main body 2 is communicated via the bypass flow path 12.

  A temperature sensor 18 that directly or indirectly measures the discharge temperature, which is the temperature of the compressed air discharged from the discharge port 2 d of the compressor body 2, is provided in the oil separation and recovery device 3. The arrangement position of the temperature sensor 18 and the temperature to be detected are not limited as described in the thirteenth embodiment.

  The controller 19 controls the three-way valve 22 according to the temperature detected by the temperature sensor 18 so that the discharge temperature is lower than the dew point. Specifically, if the controller 19 determines that the temperature of the compressed air is equal to or higher than the dew point based on the temperature measured by the temperature sensor 18, the controller 19 sets the three-way valve 22 to the first state. In this first state, all the lubricating oil from the oil separator / collector 3 passes through the oil cooler 4 and is supplied to the compressor body 2 through the first oil supply passage 7. On the other hand, if the controller 19 determines that the discharge temperature is less than the dew point based on the temperature measured by the temperature sensor 18, the controller 19 sets the three-way valve 22 to the second state. In this second state, all the lubricating oil from the oil separator / recovery unit 3 is supplied to the compressor body 2 through the bypass channel 12 without passing through the oil cooler 4.

  The lubricating oil (cooled by the oil cooler 4) supplied to the compressor main body 2 when the three-way valve 22 is in the first state is the compressor main body 2 when the three-way valve 22 is in the first state. The temperature is lower than the lubricating oil supplied to the oil (not cooled by the oil cooler 4). Therefore, the controller 19 can adjust the temperature of the lubricating oil supplied to the compressor body 2 by switching the three-way valve 22 in accordance with the temperature detected by the temperature sensor 18, thereby keeping the discharge temperature below the dew point. The controller 19 switches the three-way valve 22 from the second state to the first state when the temperature of the compressed air reaches a first set temperature that is slightly higher than the dew point, and the temperature of the compressed air is higher than the dew point. The three-way valve 22 may be switched from the first state to the second state when a slightly lower second set temperature is reached.

  Other configurations and operations of the fifteenth embodiment are the same as those of the first embodiment.

(Sixteenth embodiment)
FIG. 16 shows an oil-cooled air compressor 1 according to a sixteenth embodiment of the present invention. The oil cooler 4 cools the lubricating oil to a temperature at which the air sucked from the suction port 2 c is equal to or lower than the dew point in the compressor body 2. In other words, the oil cooler 4 cools the lubricating oil supplied to the compressor main body 2 through the first oil supply passage 7 so that the discharge temperature of the compressor main body 2 becomes the oil supply temperature that is not more than the dew point.

  The oil-cooled air compressor 1 of the first to fifteenth embodiments includes a coalescer type or gravity water tank type oil / water separator 5. On the other hand, in this embodiment, the decompression type oil-water separator 25 is provided.

  The decompression-type oil / water separator 25 includes an open channel 23, an electromagnetic valve 24, a moisture level sensor 26, and a moisture release control unit 27. In the present embodiment, the moisture release control unit 27 is provided in the controller 19.

  One end of the open channel 23 communicates with a space formed above the liquid level of the lubricating oil in the oil separator / collector 3. The other end of the open channel 23 communicates with the atmosphere outside the oil separator / collector 3. The other end of the open flow path 23 is the liquid level in the oil separator / recovery unit 3 in a state where the one end and the other end of the open flow path 23 are not in communication (during normal operation of the oil-cooled air compressor 1). What is necessary is just to communicate with the low-pressure space rather than the upper space. Therefore, the other end of the open channel 23 is not limited to the atmosphere, and may be connected to a space below atmospheric pressure (for example, a tank whose internal pressure is set below atmospheric pressure).

  The electromagnetic valve 24 is provided in the open channel 23. The electromagnetic valve 24 can be switched between a valve closing state and a valve opening state. The solenoid valve 24 may be either a normally closed type or a normally open type. The normal solenoid valve 24 is in a closed state. When the electromagnetic valve 24 is in the closed state, the communication between the space in the oil separation / recovery unit 3 and the atmosphere via the open flow path 23 is blocked. When the electromagnetic valve 24 is in the open state, the space in the oil separation / recovery unit 3 and the atmosphere communicate with each other via the open flow path 23.

  The moisture liquid level sensor 26 detects the boundary surface between the water (condensed water) and the lubricating oil in the oil separator / collector 3, that is, the moisture level (moisture level) and detects the detected moisture level. Is output to the moisture release controller 27. The moisture liquid level sensor 26 may be a contact type such as a float type or a non-contact type such as a capacitance type.

  The moisture liquid level sensor 26 is provided to detect the amount of moisture in the oil-cooled air compressor 1 (for example, in the oil separator / collector 3). The detection of the amount of water in the oil-cooled air compressor 1 is provided so as to measure the amount of water (relative water content) contained in the lubricating oil in the oil separator / collector 3 instead of the water level sensor 26. It may be performed by a moisture sensor. As the moisture sensor, a known capacitance type sensor can be used. The moisture amount measured by the moisture amount sensor is output to the moisture release control unit 27. In addition, it is the same also in other embodiment that the water | moisture-content liquid level sensor 26 can be substituted to a moisture content sensor. Therefore, the description of this point in the following embodiments is omitted unless particularly necessary.

  The moisture release control unit 27 controls the open / close state of the electromagnetic valve 24 in accordance with the moisture level level input from the moisture level sensor 26.

  Specifically, when the measured value of the moisture level input from the moisture level sensor 26 reaches a predetermined set value (first set value), the moisture release controller 27 sets the solenoid valve 24. Is temporarily switched from the closed state to the open state. This set value is set to a value at which it can be determined that the amount of water in the oil-cooled air compressor 1 (in the present embodiment, the oil separation / recovery unit 3) is large.

  When the electromagnetic valve 24 is switched from the closed state to the open state, the space in the oil separation and recovery device 3 communicates with the atmosphere via the open flow path 23. That is, the space in the oil separator / collector 3 is opened to the atmosphere. The space in the oil separator / recovery unit 3 is depressurized by opening to the atmosphere. As a result, moisture expands in the oil content collector 3 and is released to the atmosphere together with the compressed air. By being released into the atmosphere together with the compressed air, moisture is separated from the lubricating oil in the oil separator / collector 3.

  The open state of the electromagnetic valve 24 is continued to such an extent that moisture can be effectively discharged. For example, the moisture release control unit 27 may continue the open state of the electromagnetic valve 24 for a predetermined time. In addition, the moisture release control unit 27 sets a preset value (the second set value that is lower than the first set value) in which the measured value of the moisture level input from the moisture level sensor 26 is set. The valve open state of the electromagnetic valve 24 may be continued until the value is reached.

  As described above, when a moisture amount sensor is used instead of the moisture liquid level sensor 26, the moisture release control unit 27 sets a predetermined amount (for example, 10) of the moisture amount (relative moisture amount) measured by the moisture amount sensor. %), The solenoid valve 24 is temporarily switched from the closed state to the open state. The moisture release control unit 27 may continue the open state of the electromagnetic valve 24 for a predetermined time. Further, the open state of the electromagnetic valve 24 may be continued until the amount of moisture measured by the moisture amount sensor decreases to another preset value (for example, a specific value lower than 10%).

  Other configurations and operations of the sixteenth embodiment are the same as those of the first embodiment.

(17th Embodiment)
FIG. 17 shows an oil-cooled air compressor 1 according to a seventeenth embodiment of the present invention. In the present embodiment, two temperature sensors 28 and 29 are provided in place of the moisture liquid level sensor 26 (see FIG. 16) of the sixteenth embodiment. In other words, the moisture release control unit 27 in the present embodiment is a means different from that in the sixteenth embodiment, and the amount of moisture contained in the lubricating oil in the oil-cooled air compressor 1 (for example, in the oil separation / recovery unit 3) ( It is determined whether the relative water content is large.

  One temperature sensor 28 directly or indirectly measures the discharge temperature, which is the temperature of the compressed air discharged from the discharge port 2 d of the compressor body 2, and outputs the measured discharge temperature to the moisture release control unit 27. The suction temperature, which is the temperature of the air sucked from the other temperature sensor 29 and the suction port 2 c of the compressor body 2, is measured directly or indirectly, and the measured suction temperature is output to the moisture release controller 27.

  The moisture release control unit 27 includes a temperature difference between the discharge temperature measured by the temperature sensor 28 and the suction temperature measured by the temperature sensor 29, the discharge amount of the compressor body 2, and the operation time of the compressor body 2 (controller 19). The amount of water (condensed water amount) in the oil separator / recovery unit 3 is estimated or calculated on the basis of In addition, when the calculated amount of water exceeds a predetermined set value, the moisture release control unit 27 temporarily switches the electromagnetic valve 24 from the closed state to the opened state. The moisture release control unit 27 may continue the open state of the electromagnetic valve 24 for a predetermined time. In addition, the moisture release control unit 27 keeps the electromagnetic valve 24 open until the calculated amount of water drops to another preset value (for example, a specific value lower than the set value of the valve opening). It may be continued.

  Other configurations and operations of the seventeenth embodiment are the same as those of the sixteenth embodiment.

(Eighteenth embodiment)
FIG. 18 shows an oil-cooled air compressor 1 according to an eighteenth embodiment of the present invention. In the present embodiment, instead of the moisture liquid level sensor 26 (see FIG. 16) of the sixteenth embodiment, a timer 32 is provided for measuring the time during which the electromagnetic valve 24 is maintained in the closed state. In other words, the moisture release control unit 27 in the present embodiment is a means different from that in the sixteenth embodiment, and the amount of water contained in the oil in the oil-cooled air compressor 1 (for example, in the oil separation and recovery unit 3) (relative Determine whether the amount of water) is large.

  The moisture release control unit 27 temporarily closes the electromagnetic valve 24 when the time that the electromagnetic valve 24 measured by the timer 32 is maintained in a closed state reaches a predetermined set time (for example, 10 hours). Switch from state to valve open. For example, the moisture release control unit 27 continues the valve open state of the electromagnetic valve 24 for a predetermined time.

  Other configurations and operations of the eighteenth embodiment are the same as those of the sixteenth embodiment.

(Nineteenth embodiment)
FIG. 19 shows an oil-cooled air compressor 1 according to a nineteenth embodiment of the present invention. The oil cooler 4 cools the lubricating oil to a temperature at which the air sucked from the suction port 2 c is equal to or lower than the dew point in the compressor body 2. In other words, the oil cooler 4 cools the lubricating oil supplied to the compressor main body 2 through the first oil supply passage 7 so that the discharge temperature of the compressor main body 2 becomes the oil supply temperature that is not more than the dew point.

  In the sixteenth to eighteenth embodiments (FIGS. 16 to 18), the moisture release control unit 27 is a solenoid valve according to the amount of water in the oil-cooled air compressor 1 (for example, in the oil separation and recovery unit 3). The open / close state of 24 is controlled. On the other hand, the moisture release control unit 27 in the present embodiment controls the open / close state of the electromagnetic valve 24 according to the discharge pressure of the compressor body 2 instead of the amount of moisture in the oil-cooled air compressor 1. .

  In the present embodiment, a pressure sensor 33 that detects the pressure of the compressed air discharged from the discharge port 2d of the compressor body 2 is provided. The pressure sensor 33 outputs the detected pressure of compressed air (discharge pressure) to the moisture release control unit 27.

  When the discharge pressure detected by the pressure sensor 33 reaches a predetermined set value (first set value), the moisture release control unit 27 temporarily switches the electromagnetic valve 24 from the closed state to the open state. This set value is set to, for example, a discharge pressure indicating that the unload pressure or the operation stop pressure has been reached.

  When the electromagnetic valve 24 is switched from the closed state to the open state, the space in the oil separation and recovery device 3 communicates with the atmosphere via the open flow path 23. As a result, moisture expands in the decompressed oil content collector 3 and is released into the atmosphere together with the compressed air. The moisture in the oil separator / collector 3 is separated from the lubricating oil by being discharged into the atmosphere together with the compressed air.

  The open state of the electromagnetic valve 24 is continued to such an extent that moisture can be effectively discharged. For example, the moisture release control unit 27 may continue the open state of the electromagnetic valve 24 for a predetermined time. In addition, the moisture release control unit 27 operates until the measured value of the discharge pressure input from the pressure sensor 33 reaches a preset set value (second set value that is lower than the first set value). The 24 open states may be continued. By setting the solenoid valve 24 to the open state when the discharge pressure increases, the influence on the external load due to the release of moisture in the decompression type oil / water separator 25 can be reduced.

  Other configurations and operations of the nineteenth embodiment are the same as those of the sixteenth embodiment.

(20th embodiment)
FIG. 20 shows an oil-cooled air compressor 1 according to the twentieth embodiment of the present invention. In the present embodiment, the moisture release control unit 27 opens and closes the electromagnetic valve 24 according to the amount of moisture in the oil-cooled air compressor 1 (for example, in the oil separation and recovery unit 3) and the discharge pressure of the compressor body 2. Control the state. Specifically, in the present embodiment, the liquid is discharged from the water level sensor 26 that detects the same water level as in the 16th embodiment and the discharge port 2d of the compressor body 2 as in the 19th embodiment. And a pressure sensor 33 for detecting the pressure of the compressed air. The detection values of the moisture liquid level sensor 26 and the pressure sensor 33 are output to the moisture release control unit 27.

  The moisture release control unit 27 determines that the amount of moisture is large from the detection value of the moisture liquid level sensor 26 and determines that the discharge pressure of the compressor body 2 is increasing from the detection value of the pressure sensor 33. The solenoid valve 24 is temporarily switched from the closed state to the open state. The open state of the electromagnetic valve 24 is continued for a predetermined time, for example. Further, the solenoid valve 24 may be switched from the open state to the closed state based on the detected value of at least one of the moisture liquid level sensor 26 and the pressure sensor 33.

  The seventeenth and eighteenth embodiments (FIGS. 17 and 18) can also be combined with the nineteenth embodiment (FIG. 19).

  Other configurations and operations of the twentieth embodiment are the same as those of the sixteenth embodiment.

(21st Embodiment)
FIG. 21 shows an oil-cooled air compressor 1 according to a twenty-first embodiment of the present invention. In this embodiment, the oil-cooled air compressor 1 according to the sixteenth embodiment is configured such that a coalescer type or gravity water tank type oil / water separator 5 is further provided in the first oil supply passage 7. In other words, in this embodiment, the coalescer type or gravity water tank type oil / water separator 5 and the decompression type oil / water separator 25 are used in combination. As in the sixteenth embodiment, the open / close state of the electromagnetic valve 24 of the decompression type oil / water separator 25 is controlled by the moisture release controller 27 in accordance with the input from the moisture level sensor 26.

  By using the coalescer type or gravity tank type oil / water separator 5 and the decompression type oil / water separator 25 in combination, the capacity of the coalescer type or gravity tank type oil / water separator 5 can be reduced, or the capacity can be changed. Therefore, the oil / water separation performance of the oil-cooled air compressor 1 can be enhanced.

  Also in the oil-cooled air compressor 1 of the seventeenth to twentieth embodiments, a coalescer type or gravity water tank type oil / water separator 5 may be further provided in addition to the reduced pressure type oil / water separator 25. When the decompression type oil / water separator 25 and the coalescer type or gravity tank type oil / water separator 5 are used in combination, the arrangement of the oil / water separator 5 and the configuration of the path of the lubricating oil related thereto are not particularly limited. That is, any one of the sixteenth to twentieth embodiments (a configuration including the decompression-type oil / water separator 25) and the first to fifteenth embodiments (the coalescer type or gravity water tank type oil / water separator 5). Any of these may be combined.

  Other configurations and operations of the twenty-first embodiment are the same as those of the sixteenth embodiment.

(Twenty-second embodiment)
FIG. 22 shows an oil-cooled air compressor 1 according to a twenty-second embodiment of the present invention. The oil cooler 4 in the present embodiment can adjust the oil supply temperature of the lubricating oil to the compressor body 2. Specifically, the oil cooler 4 can be operated in a normal operation mode and a temperature raising operation mode.

  In the normal operation mode, the oil cooler 4 cools the lubricating oil to a temperature at which the air sucked from the suction port 2 c becomes a dew point or less in the compressor body 2. In other words, the oil cooler 4 in the normal operation mode is lubricated to be supplied to the compressor main body 2 through the first oil supply passage 7 so that the discharge temperature of the compressor main body 2 becomes the oil supply temperature that is not more than the dew point. Cool the oil.

  The oil cooler 4 in the temperature raising operation mode is provided by the first oil supply passage 7 so that the temperature of the lubricating oil in the oil separation / recovery device 3 becomes the oil supply temperature at which the temperature is higher than the dew point (for example, 80 ° C.). The lubricating oil supplied to the compressor body 2 is cooled.

  Switching from the normal operation mode to the heating operation mode can be realized by temporarily reducing the cooling capacity of the oil cooler 4. In other words, in the case of the water-cooled oil cooler 4, the cooling capacity of the oil cooler 4 is temporarily controlled by controlling the opening degree of the valve provided in the flow path of the cooling water to be smaller than that during normal operation. The temperature of the lubricating oil can be temporarily increased. Further, in the case of the fan-cooled oil cooler 4, the cooling capacity of the oil cooler 4 is temporarily reduced by controlling the fan speed to be lower than that during normal operation, so that the lubricating oil The temperature can be increased temporarily.

  The oil-cooled air compressor 1 of the first to fifteenth embodiments includes a coalescer type or gravity water tank type oil / water separator 5. On the other hand, in the present embodiment, a temperature rising type oil / water separator 35 is provided.

  As described above, the temperature rising type oil / water separator 35 includes the oil cooler 4 that can be operated in the normal operation mode and the temperature increasing operation mode, the water level sensor 26 similar to that in the sixteenth embodiment (FIG. 16), A temperature sensor 28 similar to that in the seventeenth embodiment (FIG. 17) and a temperature rise control unit 34 are provided. The temperature sensor 28 indirectly measures the temperature of the lubricating oil in the oil separation / recovery unit 3 based on the temperature (discharge temperature) of the compressed air discharged from the discharge port 2d of the compressor body 2, and the temperature increase control unit 34. Output to. The moisture liquid level sensor 26 detects the moisture liquid level in the oil separator / recovery unit 3 as the amount of moisture and outputs the detected moisture level to the temperature rise control unit 34. In the present embodiment, the temperature increase control unit 34 is provided in the controller 19.

  The temperature increase control unit 34 controls the oil cooler 4 using the moisture liquid level height input from the moisture liquid level sensor 26 and the discharge temperature input from the temperature sensor 28.

  Specifically, the temperature rise control unit 34 determines that the measured value of the moisture liquid level input from the moisture liquid level sensor 26 has reached a predetermined set value (first set value), that is, oil When it is determined that the amount of water in the cold compressor 1 is large, the oil cooler 4 is temporarily switched from the normal mode to the heating operation mode. When the oil cooler 4 enters the temperature raising operation mode, the oil supply temperature to the compressor body 2 rises, and the temperature of the lubricating oil in the oil separation / recovery device 3 becomes a temperature higher than the dew point (for example, 80 ° C.). As a result, the water in the oil separator / collector 3 evaporates and is sent to the downstream side from the outlet 3a together with the compressed air separated from the oil in the oil separator / collector 3. A dryer (not shown) is provided on the downstream side, and moisture is removed from the compressed air by this dryer.

  The temperature increase control unit 34 temporarily increases the temperature of the oil supplied into the compressor body 2 when it is determined that the amount of moisture is large, the oil cooler 4 is set in the temperature increase operation mode, and the oil separator / collector 3 The temperature of the lubricating oil inside is temporarily set to a temperature above the dew point (for example, 80 ° C.). However, the temperature increase control unit 34 sets the oil cooler 4 to the normal operation mode and sets the discharge temperature of the compressor body 2 to the dew point or less in most of the normal operation of the oil-cooled air compressor 1. As a result, it is possible to improve performance by increasing the amount of discharged air, and energy saving is improved.

  The temperature increase control unit 34 adjusts the cooling power of the oil cooler 4 based on the discharge temperature measurement value input from the temperature sensor 28 during the temperature increase operation mode. Specifically, the temperature increase control unit 34 increases the cooling power of the oil cooler 4 as the measured value of the discharge temperature increases. For example, in the case of the water-cooled oil cooler 4, the degree of opening of the valve provided in the flow path of the cooling water is set larger as the measured value of the discharge temperature increases. In the case of the fan-cooled oil cooler 4, the fan rotation speed is set higher as the discharge temperature measurement value increases. By performing such feedback control, it is possible to prevent the temperature of the lubricating oil in the oil separator / collector 3 from rising excessively.

  When the temperature rising type oil / water separator 35 is used alone as in this embodiment, when a dryer for removing moisture from the compressed air is installed, the cooling capacity cannot be reduced. However, since the temperature rising type oil / water separator 35 can be configured using many existing configurations of a normal oil-cooled air compressor, there is an advantage that oil / water separation can be realized with a simple configuration.

  Instead of the water level sensor 26, the amount of water provided to measure the amount of water (relative water content) contained in the lubricating oil in the oil-cooled air compressor 1 (for example, in the oil separator / collector 3). Sensors can be used. In this case, when the amount of moisture measured by the moisture amount sensor reaches a predetermined set value (for example, 10%), the oil cooler 4 is temporarily switched from the normal operation mode to the heating operation mode.

  Further, instead of the moisture liquid level sensor 26, as in the seventeenth embodiment (FIG. 17), the temperature difference between the measured discharge temperature and the measured suction temperature, the discharge amount of the compressor body 2, and the compressor Based on the operation time of the main body 2, the amount of water in the oil separation and recovery device 3 may be calculated. In this case, when the calculated water content reaches a predetermined set value (for example, 10%), the oil cooler 4 is temporarily switched from the normal operation mode to the heating operation mode.

  Further, when a preset time (for example, 10 hours) elapses from the count clearing time when the timer count is removed from the temperature rising operation mode, it is temporarily determined that the amount of moisture is large. The normal operation mode may be switched to the temperature raising operation mode.

  The temperature increase control unit 34 may temporarily switch the oil / water separator 35 from the normal operation mode to the temperature increase operation mode when the discharge pressure of the compressor body 2 increases. Further, the temperature rise control unit 34 determines that the amount of water in the oil-cooled air compressor 1 (for example, in the oil separation / recovery unit 3) is large and the discharge pressure of the compressor body 2 is increased. When the determination is made, the oil / water separator 4 may be temporarily switched from the normal operation mode to the temperature raising operation mode.

  Other configurations and operations of the twenty-second embodiment are the same as those of the first embodiment.

(23rd Embodiment)
FIG. 23 shows an oil-cooled air compressor 1 according to a twenty-third embodiment of the present invention. In the present embodiment, an oil temperature sensor 36 that measures the temperature (oil temperature) of the lubricating oil in the oil separator / collector 3 is provided instead of the temperature sensor 28 (detecting the discharge temperature) of the twenty-second embodiment.

  The temperature increase control unit 34 adjusts the cooling power of the oil cooler 4 based on the measured value of the oil temperature in the oil separator / collector 3 input from the oil temperature sensor 36 during the temperature increase operation mode. Specifically, the temperature increase control unit 34 increases the cooling power of the oil cooler 4 as the measured value of the oil temperature increases. For example, in the case of the water-cooled oil cooler 4, the degree of opening of the valve provided in the flow path of the cooling water is set larger as the measured value of the oil temperature increases. Further, in the case of the fan-cooled oil cooler 4, the rotational speed of the fan is set higher as the measured value of the oil temperature increases. By performing such feedback control, it is possible to prevent the temperature of the lubricating oil in the oil separator / collector 3 from rising excessively.

  Other configurations and operations of the twenty-third embodiment are the same as those of the twenty-second embodiment.

(24th Embodiment)
FIG. 24 shows an oil-cooled air compressor 1 according to a twenty-fourth embodiment of the present invention. In this embodiment, the oil-cooled air compressor 1 according to the twenty-second embodiment further includes a coalescer-type or gravity water tank-type oil-water separator 5 in the first oil supply passage 7. In other words, in this embodiment, the coalescer type or gravity water tank type oil / water separator 5 and the temperature rising type oil / water separator 35 are used in combination. As in the twenty-second embodiment, switching between the normal operation mode and the temperature increase operation mode of the oil cooler 4 in the decompression-type oil / water separator 35 is performed by the temperature increase control device 34 according to the input from the moisture liquid level sensor 26. Be controlled.

  By using the coalescer type or gravity tank type oil / water separator 5 and the temperature rising type oil / water separator 35 in combination, the capacity of the coalescer type or gravity tank type oil / water separator 5 is reduced, or the capacity is The oil-water separation performance of the oil-cooled air compressor 1 can be improved without changing.

  When the temperature rising type oil / water separator 35 and the coalescer type / gravity water tank type oil / water separator 5 are used in combination, the arrangement of the oil / water separator 5 and the configuration of the lubricating oil path related thereto are not particularly limited. That is, according to any of the 22nd and 23rd embodiments (configuration including the temperature rising type oil / water separator 35) and the first to 15th embodiments (the coalescer type or gravity water tank type oil / water separator 5). Any one of them may be combined.

  Other configurations and operations of the twenty-fourth embodiment are the same as those of the twenty-second embodiment.

(25th Embodiment)
FIG. 25 shows an oil-cooled air compressor 1 according to a twenty-fifth embodiment of the present invention. In the present embodiment, the oil-cooled air compressor 1 according to the twenty-second embodiment is further provided with a reduced-pressure oil-water separator 25 (see, for example, FIG. 16). In other words, the decompression type oil / water separator 25 and the temperature rising type oil / water separator 35 are used in combination. As in the nineteenth embodiment, the moisture release control unit 27 controls the open / close state of the electromagnetic valve 24 of the pressure-reducing oil / water separator 25 in accordance with an input from the pressure sensor 33 (detecting the discharge pressure of the compressor body 2). To do. In addition, switching between the normal operation mode and the temperature increase operation mode of the oil cooler 4 in the temperature increase type oil / water separator 35 is controlled by the temperature increase control unit 34 in accordance with an input from the pressure sensor 28.

  By using the decompression type oil / water separator 25 together with the temperature rising type oil / water separator 35, the oil / water separation performance can be achieved with a relatively simple configuration while reducing the cooling capacity of the dryer or eliminating the need for a dryer. Can be increased. Specifically, when used in combination with the pressure-reducing oil / water separator 25, the external load is reduced and the discharge pressure of the compressor body 2 (pressure in the oil separator / recoverer 3) is increased, which is detected by the pressure sensor 33. When the pressure reaches a predetermined set value (for example, when the pressure sensor detects that the unload pressure or the operation stop pressure has been reached), the temperature increase control unit 34 temporarily turns the oil cooler 4 on. As the temperature raising operation mode to be enhanced, the evaporation of moisture is promoted, and the moisture release control unit 27 temporarily opens the electromagnetic valve 24 to promote the evaporation of moisture, thereby improving the oil / water separation performance. . Further, the water thus evaporated can be released (released to the outside) from the oil separator / collector 3 to the space below the atmospheric pressure via the open flow path 23 regardless of the presence or absence of the dryer.

  The controller 19 is provided with the moisture release control unit 27 and the temperature increase control unit 34, and is provided with the open flow path 23 provided with the electromagnetic valve 24, so that the oil-cooled type of the present embodiment can be used from the existing oil-cooled air compressor. The air compressor 1 can be configured. In this respect, the oil-cooled air compressor 1 has a relatively simple configuration.

  In the twenty-fifth embodiment, the open / close state of the electromagnetic valve 24 is controlled in accordance with an input from the pressure sensor 33. However, the open / close state of the electromagnetic valve 24 of the decompression type oil / water separator 25 may be controlled in the same manner as in the sixteenth, seventeenth, eighteenth and twentieth embodiments.

  In the present embodiment, a coalescer type or gravity water tank type oil / water separator 5 (see, for example, FIG. 1) may be further provided. That is, a coalescer type or gravity water tank type oil / water separator may be used in combination with the temperature rising type and pressure reducing type oil / water separators. For example, the case where the oil-water separator 5 is provided in the 1st oil supply path | route 7 is shown with a dashed-two dotted line in FIG. In other words, the oil-water separator 5 indicated by a two-dot chain line in FIG. 25 shows a case where the present embodiment and the third embodiment (FIG. 3) are combined. In the present embodiment, when a coalescer-type or gravity water tank-type oil / water separator 5 is further provided, the configuration relating to the location of the oil / water separator 5 and the route of the lubricating oil related thereto is not particularly limited. In other words, this embodiment may be combined with any of the first embodiment (FIG. 1), the second embodiment (FIG. 2), and the fourth to fifteenth embodiments (FIGS. 4 to 15).

  Other configurations and operations of the twenty-fifth embodiment are the same as those of the twenty-second embodiment.

(26th Embodiment)
FIG. 26 shows an oil-cooled air compressor 1 according to a twenty-sixth embodiment of the present invention. In the twenty-second to twenty-fifth embodiments described above, the temperature rising type oil / water separator 35 includes the oil cooler 4 that can be operated in the normal operation mode and the temperature increasing operation mode, the moisture level sensor 26, the temperature sensor 28 or 36 and a temperature rise control unit 34. On the other hand, in the present embodiment, the temperature rise control unit 34 of the controller 19 controls the rotation speed of the drive device 37 of the rotor (see reference numeral 2b in FIG. A separation device 35 is configured. The present embodiment can be configured in the same manner as any of the twenty-second to twenty-fifth embodiments, except for the configuration in which the drive device 37 is a control target. Therefore, in the present embodiment, an example in which the control target of the twenty-second embodiment is replaced with the drive device 37 will be described.

  The drive device 37 (for example, an electric motor) can switch the operation state between a normal operation mode and a temperature raising operation mode. Switching between the normal operation mode and the temperature increase operation mode can be realized by temporarily increasing the rotational speed of the drive device 37 via the inverter by the temperature increase control unit 34. Specifically, in other words, the drive device 37 can rotate the rotor of the compressor body 2 and is controlled so that the rotational speed of the rotor is higher in the temperature raising operation mode than in the normal operation mode.

  In the normal operation mode, the rotational speed of the drive device 37 is set so that the air sucked from the suction port 2c is below the dew point in the compressor body 2 by the lubricating oil cooled by the oil cooler 4.

  When the operation state is the temperature raising operation mode, the compression work of the compressor body 2 is increased by increasing the rotational speed of the rotor, and the discharge temperature of the compressor body 2 is increased. By this increase in the discharge temperature, the temperature of the lubricating oil in the oil separator / collector 3 can be temporarily raised to a temperature above the dew point (for example, 80 ° C.). As a result, the water in the oil separator / collector 3 evaporates and is sent to the downstream side from the outlet 3a together with the compressed air separated from the oil in the oil separator / collector 3. A dryer (not shown) is provided on the downstream side, and moisture is removed from the compressed air by this dryer. In other words, in the temperature raising mode, the temperature raising control unit 34 controls the driving device 37 so that the temperature of the lubricating oil in the oil separator / collector 3 temporarily becomes the rotational speed of the driving device above the dew point.

  In the present embodiment, the temperature increase control unit 34 of the controller 19 controls switching between the normal operation mode and the temperature increase operation mode of the drive device 37 in accordance with the input from the moisture liquid level sensor 26 as in the twenty-second embodiment. doing. Specifically, the temperature increase control unit 34, when the measured value of the moisture liquid level input from the moisture liquid level sensor 26 reaches a predetermined set value (first set value), that is, When it is determined that the amount of moisture in the oil-cooled compressor 1 is large, the drive device 37 is temporarily switched from the normal mode to the temperature raising operation mode. Also in the present embodiment, the moisture liquid level sensor 26 can be replaced with a moisture amount sensor.

  Instead of the moisture liquid level sensor 26, as in the seventeenth embodiment (FIG. 17), the temperature difference between the measured discharge temperature and the measured suction temperature, the discharge amount of the compressor body 2, and the compressor body 2 The amount of water in the oil separator / recoverer 3 may be calculated based on the operation time of In this case, when the calculated water content reaches a predetermined set value (for example, 10%), the drive device 37 is temporarily switched from the normal operation mode to the temperature raising operation mode.

  When a preset time (for example, 10 hours) elapses from the count clearing point when the timer count is removed from the temperature rising operation mode, it is determined that the amount of moisture is large, and the drive device 37 is temporarily Therefore, the normal operation mode may be switched to the temperature raising operation mode.

  The temperature increase control unit 34 is a normal operation mode of the drive device 37 in accordance with an input from a pressure sensor (for example, reference numeral 33 in FIG. 19) that detects the pressure of the compressed air discharged from the discharge port 2d of the compressor body 2. And switching of the heating operation mode may be controlled. In this case, when the discharge pressure detected by the pressure sensor 33 reaches a predetermined set value, the temperature increase number control unit 34 temporarily switches the drive device 37 from the normal mode to the temperature increase operation mode. The rotation control unit 38 controls the switching between the normal operation mode and the temperature raising operation mode of the drive device 37 based on the amount of moisture detected by means such as the moisture level sensor 26 and the input from both pressure sensors. Good.

  In addition, although description is abbreviate | omitted in description of the above-mentioned embodiment, especially about the method of calculating | requiring the dew point required for judgment whether the temperature of the compressed air discharged from the compressor main body 2 is more than a dew point. It is not limited. For example, the pressure measurement value and the temperature measurement value of the compressed air immediately before or immediately after the discharge may be obtained. The pressure measurement value of the compressed air in the oil separation and recovery unit and the temperature measurement value of the compressed air or oil in the oil separation and recovery unit You may ask for it. In the latter case, when the pressure loss from the discharge port 2d to the oil separation / recovery device is not substantially negligible, the pressure value necessary for calculating the dew point is determined by taking the pressure loss into consideration in the pressure measurement value in the oil separation / recovery device. Can be sought. In the latter case, based on the temperature drop that occurs from the discharge port 2d to the oil separator / recoverer, the temperature required for calculating the dew point depends on the measured temperature of the compressed air or oil in the oil separator / recoverer. It can be determined in consideration of the amount of heat (the amount of heat released from the pipes and oil separator / collector constituting the discharge flow path).

  Moreover, although description is abbreviate | omitted in description of the above-mentioned embodiment, when connecting piping to the bottom face of an oil separation recovery device, the bottom part of an oil separation recovery device is formed in spherical shape, and piping is connected to the lowest part. It is desirable. By doing so, oil with much water contamination can be extracted.

  Moreover, in the schematic diagram explaining the above-mentioned embodiment, illustration is abbreviate | omitted in the well-known structure like the bearing which supports rotor 2b, 2b and the bearing oil supply line which supplies oil with respect to the bearing.

  The open channel is preferably one that can communicate with a space below atmospheric pressure. What opens an open channel | path to air | atmosphere is especially preferable at the point which does not complicate apparatus structure.

  In addition, when the moisture release control unit and the temperature increase control unit determine that the amount of water in the oil-cooled air compressor 1 is large, the solenoid valve 24 is automatically opened or the temperature increase operation mode is automatically set. However, the present invention is not limited to the one that starts the control of the oil-cooled air compressor 1. For example, when it is determined that the amount of water in the oil-cooled air compressor 1 is large, an alarm is given by a display or the like, and an electric signal based on a human operation is received to open the solenoid valve 24 or raise the temperature. Control may be started by switching to the operation mode.

  Further, in the above-described embodiment, as the temperature rising type oil / water separation device 35 (temperature rising control unit), in order to temporarily control the temperature of the lubricating oil in the oil separation / recovery unit 3 to a dew point or higher, an oil cooler The one that temporarily decreases the cooling capacity of 4 and the one that temporarily increases the compression work of the compressor body 2 are exemplified. However, the temperature rising type oil / water separator 35 (temperature rising control unit) is not limited to these. For example, the oil / water separation device temporarily controls the temperature of the lubricating oil in the oil separation / recovery unit 3 to be above the dew point by appropriately combining and controlling the cooling capacity of the oil cooler 4 and the compression work of the compressor body 2. It may be configured to control.

DESCRIPTION OF SYMBOLS 1 Oil-cooled air compressor 2 Compressor body 2a Rotor chamber 2b Rotor 2c Suction port 2d Discharge port 3 Oil separator / collector 3a Outlet 4 Oil cooler 5, 25, 35 Oil / water separator 6 Discharge flow path 7 First oil supply Flow path 8 Second oil supply flow path 9 Return flow path 10, 11, 14 Pump 12 Bypass flow path 13A, 13B On-off valve 15 Circulation flow path 16, 22 Three-way valve 17 Bypass oil supply flow path 18 Temperature sensor 19 Controller 21, 121 Solenoid valve 23 Open flow path 24 Solenoid valve 26 Water level sensor 27 Water release controller 28 Temperature sensor 29 Temperature sensor 31, 32 Timer 33 Pressure sensor 34 Temperature controller 36 Oil temperature sensor 37 Drive device

Claims (42)

An oil-cooled compressor body that compresses and discharges the sucked air; and
An oil separation and recovery device for separating and recovering the lubricating oil from the compressed air discharged from the compressor body;
A first oil supply passage that connects the oil separator and the suction side of the compressor body;
An oil-cooled air compressor, comprising: an oil cooler that is provided in the first oil supply passage and that cools the lubricating oil to an oil supply temperature at which the air is equal to or lower than a dew point in the compressor body.   2. The oil-cooled air compressor according to claim 1, further comprising an oil-water separator that separates moisture generated in the compressor body during air compression from the lubricating oil outside the compressor body.   The oil-cooled air compressor according to claim 2, wherein the oil-water separator is a coalescer oil-water separator.   The oil-cooled air compressor according to claim 2, wherein the oil-water separator is a gravity water tank type oil-water separator.   The oil-cooled air compressor according to claim 2, wherein the oil / water separator is provided in a discharge passage that connects a discharge port of the compressor body and the oil separator / collector.   The oil-cooled air compressor according to claim 2, wherein the oil / water separator is provided in the oil separator / recovery unit.   The oil-cooled air compressor according to claim 2, wherein the oil / water separator is provided in the first oil supply passage. In addition to the first oil supply flow path, a second oil supply flow path for connecting the oil separator / collector and the compressor body is provided,
The oil-cooled air compressor according to claim 2, wherein the oil-water separator is provided in the second oil supply passage.   The oil-cooled air compressor according to claim 8, wherein the second oil supply passage provided with the oil / water separator is a passage for supplying oil from the oil separation / recovery device to a suction port of the compressor body. .   The said 2nd oil supply flow path in which the said oil-water separation apparatus was provided is a flow path which supplies oil to the space part immediately after closure of the rotor chamber of the said compressor main body from the said oil separation collection | recovery device. Oil-cooled air compressor.   The oil-cooled air compressor according to claim 8, wherein the second oil supply passage provided with the oil / water separator is a passage for supplying oil from the oil separation / recovery device to a rotor of the compressor body.   The said 2nd oil supply flow path in which the said oil-water separation apparatus was provided is a flow path which supplies oil to the space part just before the discharge outlet of the rotor chamber of the said compressor main body from the said oil separation collection | recovery device. Oil-cooled air compressor. In addition to the first oil supply flow path, a return flow path that connects the oil separation and recovery device and a flow path immediately after the discharge port of the compressor body;
A pump that is provided in the return flow path and pumps the lubricating oil from the oil separation and recovery device toward the flow path immediately after the discharge port of the compressor body,
The oil-cooled air compressor according to claim 2, wherein the oil-water separator is provided in the return flow path. A bypass flow path that bypasses the oil cooler from the oil separation and recovery side and joins the first oil supply flow path;
The oil-cooled air compressor according to claim 2, wherein the oil / water separator is provided in the bypass flow path.   The oil-cooled air according to claim 14, wherein the bypass flow path provided with the oil / water separator connects the oil separation / recovery unit and the first oil supply flow path on the downstream side of the oil cooler. Compressor.   The bypass channel provided with the oil / water separator connects the first oil supply channel upstream of the oil cooler and the first oil supply channel downstream of the oil cooler, The oil-cooled air compressor according to claim 14. A circulation channel that returns from the oil separation and recovery device to the oil separation and recovery device via a pump,
The oil-cooled air compressor according to claim 2, wherein the oil-water separator is provided in the circulation channel.   The oil-cooled air compressor according to any one of claims 8 to 17, wherein an on-off valve capable of shutting off the flow path is provided before and after the oil-water separator.   19. The oil supply temperature adjustment mechanism for adjusting the oil supply temperature to the compressor main body so that the temperature of the compressed air discharged from the compressor main body becomes a predetermined temperature equal to or lower than a dew point. The oil-cooled air compressor according to item 1. A three-way valve provided upstream of the oil cooler in the first oil supply passage;
A bypass oil supply passage connected from the three-way valve to the suction side of the compressor body;
A temperature sensor that directly or indirectly measures the temperature of the compressed air discharged from the compressor body;
If it is determined that the temperature of the compressed air discharged from the compressor main body is equal to or higher than the dew point based on the temperature measured by the temperature sensor, it passes through the oil cooler and passes through the first oil supply passage. The three-way valve is switched so that lubricating oil is supplied to the compressor body, and the temperature of the compressed air discharged from the compressor body is determined to be less than the dew point based on the temperature measured by the temperature sensor. And a controller for switching the three-way valve so that lubricating oil is supplied from the bypass oil supply passage to the compressor body without passing through the oil cooler. The oil-cooled air compressor according to any one of the above. An on-off valve provided upstream of the oil cooler in the first oil supply passage;
A temperature sensor that directly or indirectly measures the temperature of the compressed air discharged from the compressor body;
If it is determined that the temperature of the compressed air discharged from the compressor body is equal to or higher than the dew point based on the temperature measured by the temperature sensor, the on-off valve is opened and the oil cooler is passed through. Lubricating oil is supplied from the first oil supply passage to the compressor main body, and it is determined that the temperature of the compressed air discharged from the compressor main body is lower than the dew point based on the temperature measured by the temperature sensor. And a controller for supplying lubricating oil from the second oil supply passage to the compressor main body without closing the on-off valve and passing through the oil cooler. The oil-cooled air compressor according to any one of 12. An on-off valve provided upstream of the oil cooler in the first oil supply passage;
A temperature sensor that directly or indirectly measures the temperature of the compressed air discharged from the compressor body;
If it is determined that the temperature of the compressed air discharged from the compressor body is equal to or higher than the dew point based on the temperature measured by the temperature sensor, the on-off valve is opened and the oil cooler is passed through. Lubricating oil is supplied from the first oil supply passage to the compressor main body, and it is determined that the temperature of the compressed air discharged from the compressor main body is lower than the dew point based on the temperature measured by the temperature sensor. And a controller that supplies the lubricating oil from the bypass flow path to the compressor main body without closing the on-off valve and passing through the oil cooler. The oil-cooled air compressor according to claim 1. A three-way valve provided at a branch point from the first oil supply passage of the bypass passage;
A temperature sensor that directly or indirectly measures the temperature of the compressed air discharged from the compressor body;
If it is determined that the temperature of the compressed air discharged from the compressor main body is equal to or higher than the dew point based on the temperature measured by the temperature sensor, it passes through the oil cooler and passes through the first oil supply passage. The three-way valve is switched so that lubricating oil is supplied to the compressor body, and the temperature of the compressed air discharged from the compressor body is determined to be less than the dew point based on the temperature measured by the temperature sensor. The oil-cooled type according to claim 16, further comprising a controller that switches the three-way valve so that lubricating oil is supplied from the bypass flow path to the compressor body without passing through the oil cooler. air compressor.   The oil-cooled air compressor according to any one of claims 2 to 23, wherein the lubricating oil has hydrophobicity.   The oil-cooled air compressor according to any one of claims 2 to 24, wherein a specific gravity of the lubricating oil is 0.95 or less. The oil-water separator is
An open flow path that connects a space above the liquid level in the oil separation and recovery unit and a space lower in pressure than this space;
A solenoid valve provided in the open flow path;
The electromagnetic valve is opened in accordance with at least one of the amount of water contained in the lubricating oil and the discharge pressure of the compressor body, and the compressed air in the space in the oil separation / recovery device is changed to the low pressure space. The oil-cooled air compressor according to claim 2, further comprising: a moisture release control unit that is discharged. A first sensor that directly or indirectly detects the amount of water contained in the lubricating oil;
27. The oil-cooled air compressor according to claim 26, wherein the moisture release controller temporarily opens the electromagnetic valve when the amount of moisture detected by the first sensor exceeds a set value.   28. The oil-cooled air compressor according to claim 27, wherein the first sensor is a sensor that detects a water liquid level height in the oil separator / recovery unit.   28. The oil-cooled air compressor according to claim 27, wherein the first sensor is a sensor that detects a moisture content contained in the lubricating liquid in the oil separator / recovery unit. A second sensor that directly or indirectly measures a discharge temperature that is a temperature of the compressed air discharged from the compressor body;
A third sensor for directly or indirectly measuring a suction temperature that is a temperature of air sucked into the compressor body,
The moisture release control unit calculates the amount of condensed water in the oil separation and recovery unit based on a temperature difference between the discharge temperature measured by the second sensor and the suction temperature measured by the third sensor. The oil-cooled compressor according to claim 26, wherein when the calculated amount of condensed water exceeds a set value, the solenoid valve is temporarily opened. A fourth sensor for detecting the pressure of the compressed air discharged from the compressor body;
27. The oil-cooled compressor according to claim 26, wherein the moisture release controller temporarily opens the electromagnetic valve when a pressure of the compressed air detected by the fourth sensor exceeds a set value. The oil cooler is capable of adjusting a supply temperature of the lubricating oil to the compressor body,
In the oil / water separator, the temperature of the lubricating oil in the oil separator / collector temporarily exceeds the dew point according to at least one of the amount of water contained in the lubricating oil and the discharge pressure of the compressor body. The hydraulic-pneumatic compressor according to claim 2, further comprising a temperature rise control unit that controls the oil cooler so as to reach an oil supply temperature. The rotor of the compressor body can be rotationally driven by a driving device,
The oil / water separator rotates at a temperature at which the temperature of the lubricating oil in the oil separator / collector temporarily exceeds the dew point according to at least one of the amount of water contained in the lubricating oil and the discharge pressure of the compressor body. The hydraulic-pneumatic compressor according to claim 2, further comprising a temperature rise control unit that controls the driving device so as to be a number. A first sensor that directly or indirectly detects the amount of water contained in the lubricating oil;
When the water content detected by the first sensor exceeds a set value, the temperature rise control unit
The oil-cooled air compressor according to claim 32 or 33, wherein the oil cooler or the drive device is controlled such that the temperature of the lubricating oil in the oil separator / collector temporarily exceeds a dew point. .   35. The oil-cooled air compressor according to claim 34, wherein the first sensor is a sensor that detects a liquid level of water in the oil separator / recovery unit.   35. The oil-cooled air compressor according to claim 34, wherein the first sensor is a sensor that detects the amount of water contained in the lubricating liquid in the oil separation and recovery device. A second sensor that directly or indirectly measures a discharge temperature that is a temperature of the compressed air discharged from the compressor body;
A third sensor for directly or indirectly measuring a suction temperature that is a temperature of air sucked into the compressor body,
The temperature increase control unit calculates the amount of condensed water in the oil separation and recovery unit based on a temperature difference between the discharge temperature measured by the second sensor and the suction temperature measured by the third sensor. When the calculated amount of condensed water exceeds a set value, the oil cooler or the drive device is controlled so that the temperature of the lubricating oil in the oil separation and recovery device temporarily exceeds the dew point. The oil-cooled compressor according to claim 33. A fourth sensor for detecting the pressure of the compressed air discharged from the compressor body;
When the pressure of the compressed air detected by the fourth sensor exceeds a set value, the temperature rise control unit is configured so that the temperature of the lubricating oil in the oil separator / collector temporarily exceeds the dew point. The oil-cooled compressor according to claim 32 or 33, which controls a cooler or the driving device. An oil-cooled compressor body that compresses and discharges the sucked air; and
An oil separation and recovery device for separating and recovering the lubricating oil from the compressed air discharged from the compressor body;
An oil supply passage connecting the oil separator and the suction side of the compressor body;
An oil-cooled air compressor control method comprising an oil cooler provided in the oil supply flow path,
A control method for an oil-cooled air compressor, wherein the lubricating oil is cooled by the oil cooler so that the air is below a dew point in the compressor body. An oil-cooled compressor body that compresses and discharges the sucked air; and
An oil separation and recovery device for separating and recovering the lubricating oil from the compressed air discharged from the compressor body;
An oil supply passage connecting the oil separator and the suction side of the compressor body;
An oil-cooled air compressor control method comprising an oil cooler provided in the oil supply flow path,
A control method for an oil-cooled air compressor, wherein the lubricating oil is cooled by the oil cooler so that the temperature of compressed air discharged from the compressor body is equal to or lower than a dew point.   The oil cooler temporarily adjusts the temperature of the lubricating oil in the oil separator / collector above the dew point according to at least one of the amount of water contained in the lubricating oil and the discharge pressure of the compressor body. 40. The method of controlling a hydraulic pneumatic compressor according to claim 38 or 39, wherein the lubricating oil is cooled.   In accordance with at least one of the amount of water contained in the lubricating oil and the discharge pressure of the compressor main body, the temperature of the lubricating oil in the oil separation / recovery unit is temporarily adjusted so that the temperature of the lubricating oil in the oil separating / collecting device exceeds the dew point. 41. The method of controlling a hydraulic pneumatic compressor according to claim 39 or claim 40, wherein the rotational speed of a drive device that rotationally drives the rotor is increased.

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