JP5132232B2 - Oil level detection method for oil sump, oil supply control method, gas compression device provided with these, and air conditioner provided with this gas compression device - Google Patents

Description

  The present invention relates to a method for detecting the level of lubricating oil in a sump supplied to a compressor, an oil supply control method, a gas compression device including these, and an air conditioner including the gas compression device.

In the gas compressor, the lubricating oil in the sump is supplied to the compressor to lubricate the sliding part, and mixed with the gas compressed by the compressor to cool it. When the amount of oil decreases and supply shortage occurs, wear and failure of the sliding portion of the compressor occur, and the gas compressed by the compressor is not sufficiently cooled.
For this reason, it is necessary to always detect the amount of lubricating oil in the sump and to take measures such as stopping the compressor when the amount of oil falls below a predetermined amount.

  As a conventional method for detecting the amount of oil in a sump, a float type oil level detector connected to the oil separator by a pressure equalizing communication pipe and an oil communication pipe is installed, and the oil level drops to the float position. There is one that detects this (for example, see Patent Document 1).

In addition, there is a type in which a capacitance level sensor is provided in an oil tank of a compressor to detect an oil level (see, for example, Patent Document 2).
Furthermore, there is one that detects an oil level by transmitting ultrasonic waves into a high-pressure gas container (see, for example, Patent Document 3).

Japanese Patent Laid-Open No. 11-83249 (second page, FIG. 1) JP-A-5-172074 (page 3-4, FIG. 1) JP 2000-337946 A (page 3-4, FIG. 1)

  In the oil-cooled compressor, sludge is gradually generated or contaminated in the lubricating oil due to wear of the sliding portion or intrusion of dust from the outside air with long-term operation. Since the oil level detector has a mechanical movable part, there is a problem that the reproducibility of the oil level detection deteriorates when sludge or the like adheres to the movable part. Moreover, since the reliability with respect to vibration is low, it is not preferable to employ it in a device that is mounted on a vehicle or the like and constantly receives vibration.

  In the case of the electrostatic capacitance level sensor of Patent Document 2, there is no problem as in the float type because there is no moving part, but if sludge generated in the lubricating oil adheres to the detection tube due to long-term use, a detection error will occur. Therefore, it is necessary to periodically remove the deposits, and maintenance is troublesome. In addition, an external power source for detecting the oil level is necessary, and there is a problem that the configuration as a system becomes complicated.

  In the case of the ultrasonic method of Patent Document 3, since the measurement method uses reflection from the oil surface, measurement errors are likely to occur if there are obstacles or foreign objects in the reflection path, and it occurs in the lubricating oil due to long-term use. There is a risk of false detection due to sludge and the like. Further, an external power supply for detection is required as in the case of the electrostatic capacitance type, and there is a problem that the configuration as a system becomes complicated.

  The present invention has been made in order to solve the above-described problems, and has a simple structure, is not affected by sludge generated in the lubricating oil, and is highly reliable in the oil sump of the compressor with respect to vibration. It is an object of the present invention to provide an oil level detection method, an oil supply control method for a compressor, a gas compression device including these, and an air conditioner including the gas compression device.

In the oil level detection method according to the present invention, oil mixed in compressed gas discharged from a compressor is separated by an oil separator and stored in a sump, and the oil in the sump is supplied to the compressor. In the gas compression apparatus, a plurality of the compressors are connected in parallel and the discharge pipes are joined to the discharge pipes, and an oil distributor is provided in an oil supply pipe for supplying oil to the compressors. And the plurality of compressors are connected with oil pipes having different height positions, and when the oil level in the sump is lowered and the compressed gas enters the oil supply pipe, any of the oil pipes as crab intensively the compressed gas flows, the oil level of oil in the oil sump, in which so as to detect the temperature of the compressed gas discharged from the compressor.

In the oil supply control method according to the present invention, the oil mixed in the compressed gas discharged from the compressor is separated by an oil separator and stored in an oil sump, and the oil in the sump is stored in the oil supply pipe by the oil supply pipe. in the gas compressor which is adapted to supply to the compressor, provided with a temperature sensor for detecting the temperature of the compressed gas flowing through the discharge pipe of the compressor, high suction mouth merging into the oil supply pipe the oil sump Two suction pipes having different positions are provided, a normally open solenoid valve is provided in the upper suction pipe, the oil level in the sump is lowered, and the compressed gas enters the upper suction pipe and when the temperature rise of the compressed gas discharged from the compressor the temperature sensor detects is obtained so as to close the solenoid valve.

The gas compression apparatus according to the present invention includes both or one of the oil level detection method and the oil supply control method.
Moreover, the air conditioning apparatus which concerns on this invention is equipped with said gas compression apparatus.

  According to the oil level detection method of the present invention, the structure is simple, and there is no need to consider the trouble and maintenance of the level meter as in the past, and even if sludge occurs in the lubricating oil, the oil level detection is possible. It is not affected by accuracy. Furthermore, since there is no influence by vibration, there is no problem even if it is adopted in a device that is mounted on a vehicle or the like and constantly receives vibration.

  According to the oil supply control method of the gas compression apparatus according to the present invention, not only the same effects as described above can be obtained, but also damage due to seizure of the compressor over the long term, accidents due to abnormal increase in discharge temperature, etc. can be prevented. can do.

According to the gas compression device concerning the present invention, the above-mentioned effect can be acquired.
Further, according to the air conditioner of the present invention, no maintenance is required for a long time, and there is no problem even if it is mounted on a vehicle or the like that is constantly subjected to vibration.

[Embodiment 1]
FIG. 1 is a block diagram showing a cycle configuration of a gas compression apparatus according to Embodiment 1 of the present invention, and FIG. 2 is an explanatory diagram of a sump of FIG.
As shown in FIG. 1, the gas compression device P according to the present embodiment includes a suction pipe 5 provided in a sump 3 in which lubricating oil 4 (hereinafter sometimes simply referred to as oil) is stored in a lower portion, It is sent to the compressor 1 through an oil filter 7 and an oil cooler 8 provided in the oil supply pipe 6 to lubricate the sliding portion, and is mixed with the outside air (gas) introduced into the compressor 1 through the air filter 2. And is discharged from the discharge pipe 9 to the oil separator 10 provided in the oil sump 3. Then, the oil in the compressed gas is separated by the oil separator 10, the compressed gas is sent to the dehumidifier 12, for example, by the air supply pipe 11, and the separated oil is stored in the oil sump 3.

In the gas compression device P configured as described above, the suction pipe 5 provided in the sump 3 has a suction port in the vicinity of the oil level 4b set below the normal oil level 4a as shown in FIG. Is connected to the oil supply pipe 6 outside the oil sump 3.
The discharge pipe 9 is provided with a temperature sensor 13 for detecting the temperature of the compressed gas discharged from the compressor 1 (hereinafter referred to as discharge temperature).

  Next, the operation of the present embodiment configured as described above will be described with reference to FIGS. 3 is a graph showing the relationship between the discharge temperature of the compressed gas discharged from the compressor 1 and the oil level of the lubricating oil 4 stored in the sump 3, and FIG. 4 shows the lubricating oil 4 in the sump 3. 5 is a flowchart of oil level detection and oil supply control.

When the operation of the gas compression device P is started (step S ₁ ), the discharge temperature of the compressed gas discharged from the compressor 1 to the discharge pipe 9 rises from the outside air temperature T _0, but is supplied from the sump 3. Since the sliding portion of the compressor 1 is lubricated and cooled by the lubricating oil 4 mixed in the compressed gas, the amount of lubricating oil is between the normal oil level 4a and the oil level 4b (hereinafter referred to as normal oil amount). If so, since the lubricating oil is sent from the suction pipe 5 to the oil supply pipe 6, the discharge temperature is at a certain temperature T ₁ according to the operating conditions (pressure, outside air temperature, operating rate, etc.). Stabilize.

However, when the amount of lubricating oil decreases due to long-term use or for some reason (step S ₂ ) and the oil level becomes 4b or less (step S ₃ ), the suction pipe 5 is in the sump 3. As the air starts to be sucked in, the supply amount of the lubricating oil 4 decreases, the lubricating ability of the sliding portion by the lubricating oil 4 and the cooling capacity of the compressed gas decrease, and the discharge temperature gradually rises (step S ₄ ). .

Then, when the discharge temperature detected by the temperature sensor 13 provided in the discharge pipe 9 becomes equal to or higher than the constant temperature T ₂ (step S ₅ ), it is determined that the oil level of the lubricating oil 4 is lowered and therefore the oil amount is lowered. Then, an appropriate measure is taken such as generating an alarm or stopping the operation of the compressor 1 (step S ₆ ) to prevent seizure of the sliding portion of the compressor 1.

FIG. 5 is an explanatory diagram of a sump of another example of the present embodiment.
In this example, a first suction pipe 5a is provided in the vicinity of the oil level 4b set below the normal oil level 4a, and an oil level 4c set below the oil level 4b. A second suction pipe 5 b in which a suction port is located in the vicinity of is provided, and both suction pipes 5 a and 5 b are joined to the oil supply pipe 6 outside the oil sump 3.

In the gas compression device P described above, when the oil level becomes 4b or less, a complete oil-free operation is performed, so that the discharge temperature rises. However, before the temperature sensor 13 detects an increase in the discharge temperature, the compressor 1 Since there is no oil supply, the compressor 1 may be damaged such as seizure.
In the present example, in order to solve such a problem, the second suction is performed after the air enters the first suction pipe 5a and becomes in an oil-free state until the operation of the compressor 1 is stopped. By supplying the lubricating oil 4 from the pipe 5b to the compressor, the compressor 1 is prevented from being damaged.

  In the above description, the compressor 1 and the oil sump 3 in which the oil separator 10 is built are shown separately. However, the present invention also applies to a compressor in which the oil separator 10 and the sump 3 are built. (The same applies to the other embodiments described below).

The gas compression apparatus according to the present embodiment is provided with a temperature sensor 13 in the discharge pipe 9 through which compressed gas is discharged from the compressor 1 without using a level meter that detects the oil level of the sump. By detecting the discharge temperature by the sensor 13, a decrease in the oil level in the sump 3 is detected, so there is no need to consider malfunctions and maintenance of the level gauge as in the past. Further, even when sludge is generated in the lubricating oil 4, the detection accuracy of the oil level is not affected.
Furthermore, since there is no influence by vibration, there is no problem even if it is employed in a device that is mounted on a vehicle or the like and that constantly receives vibration.

[Embodiment 2]
6 is a block diagram showing a cycle configuration of a gas compression apparatus according to Embodiment 2 of the present invention, FIG. 7 is a configuration explanatory diagram of the oil distributor of FIG. 6, FIG. 8 is an operation explanatory diagram of the oil distributor of FIG. 9 is a graph showing the relationship between the discharge temperature and the oil level of the sump, and FIG. 10 is a flowchart for explaining the operation of the present embodiment. The same parts as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

  The gas compression device P according to the present embodiment has almost the same configuration as the gas compression device P according to the first embodiment, but includes a plurality of compressors (first to third compressors in the figure). 1a, 1b, and 1c) are connected in parallel, and the discharge pipes 9a, 9b, and 9c are joined to the discharge pipe 9, and an oil distributor 14 is provided in the oil supply pipe 6, and the oil distributor 14 supplies oil. The pipe 6 is branched into first to third oil distribution pipes 6a, 6b, 6c, the first compressor 1a from the first oil distribution pipe 6a, the second compressor 1b from the second oil distribution pipe 6b, The lubricating oil 4 is supplied to the third compressor 1c from the third oil distribution pipe 6c.

As shown in FIG. 7, the oil distributor 14 branches the oil supply pipe 6 into three oil distribution pipes 6a, 6b, 6c, and connects the oil distribution pipe 6c connected to the third compressor 1c to other oil distribution pipes. It is provided at a position higher than 6a and 6b.
And if the lubricating oil 4 in the sump 3 is a normal oil quantity (between the oil level 4a and 4b of FIG. 2), since the oil supply piping 6 is full, each oil distribution piping 6a, 6b, 6c is also full of oil as shown in FIG.

  If the amount of oil in the sump 3 decreases and becomes lower than the oil level 4b and air enters the oil supply pipe 6, as shown in FIG. 8, the oil distribution pipe 6a, Although the lubricating oil 4 flows through 6b, air tends to flow intensively through the oil distribution pipe 6c at a position where the outlet is high.

Next, the operation of the present embodiment will be described with reference to FIGS.
When the operation is started (step S ₁ ), the discharge temperature of the compressed gas discharged from the compressors 1 a, 1 b, 1 c rises from the outside air temperature T _0, but the compressed gas is cooled by the lubricating oil 4. If the lubricating oil 4 is a normal oil amount, the discharge temperature is stabilized at a certain temperature T ₁ according to the operating conditions.

However, when the oil level drops (step S ₂ ) and falls below 4b (step S ₃ ) due to long-term use or for some reason, air starts to be sucked in from the suction pipe 5 of the sump 3, so mixed air Since the flow rate of the lubricating oil 4 in the oil distribution pipe 6c through which the oil flows intensively decreases and the lubrication and cooling capacity of the third compressor 1c decreases, the discharge temperature is higher than the discharge temperatures of the other compressors 1a and 1b. Te increases greatly (step S _4).

This discharge temperature is detected by the temperature sensor 13, if the discharge temperature becomes constant temperature T ₂ or more (step S ₆₎ emits an alarm is determined that the lowering of the oil level in the oil sump 3, or the only 3 of the compressor 1c and take appropriate measures such as stopping (step S _7).
In this case, since the lubricating oil 4 is normally supplied from the oil distribution pipes 6a and 6b to the first and second compressors 1a and 1b, as shown in FIG. Can continue. The first reduced further oil level, the second oil pipe 6a, the air enters the 6b, when the first, second compressor 1a, the discharge temperature of 1b exceeds T ₂ are, Measures such as issuing an alarm or stopping the operation of the first and second compressors 1a and 1b are taken.

In the above description, the case where the increase in the discharge temperature of the third compressor 1c is detected by the temperature sensor 13 provided in the discharge pipe 9 is shown. However, a temperature sensor is provided in the discharge pipe 9c of the third compressor 1c. It may be provided to detect the discharge temperature.
Moreover, although the case where the three compressors 1a-1c were connected in parallel was shown, two or more compressors may be connected in parallel, and in this case, the oil distributor 14 and the like are configured in accordance with the above. Thus, similar actions and effects can be obtained.

Furthermore, although the case where the one suction pipe 5 was provided in the sump 3 was shown, as shown in FIG. 5 of Embodiment 1, the two suction pipes 5a and 5b from which the height position of a suction inlet differs are shown. May be provided to join the oil supply pipe 6.
In the oil distributor 14, a plurality of branch pipes may be provided in the vertical direction, and the compressors 1a to 1c into which air has entered may be stopped sequentially.

  According to the present embodiment, a plurality of compressors are connected in parallel to constitute the gas compression device P, and the oil level of the lubricating oil 4 in the sump 3 is lowered and air is mixed into the oil supply pipe 6. In such a case, the air is concentrated and flows to a specific compressor. Therefore, by taking measures such as stopping the compressor, even if the oil level drops, the other compressor compresses the gas. The operation of the device 4 can be continued, and the oil level detection accuracy can be further improved.

[Embodiment 3]
FIG. 11 is a block diagram showing a cycle configuration of the gas compression apparatus according to Embodiment 3 of the present invention, FIG. 12 is an explanatory diagram of the oil sump in FIG. 11, and FIG. 13 is the discharge temperature and the oil level of the lubricating oil in the sump. FIG. 14 is a flowchart for explaining the operation of the present invention. The same parts as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

  In the present embodiment, first and second suction pipes 5a and 5b are provided in the oil sump 3, and the first suction pipe 5a is an oil set below the normal oil level 4a. The suction port is positioned in the vicinity of the surface level 4b, and the second suction pipe 5b has the suction port positioned in the vicinity of the oil level 4c set further below the oil level 4b. , 5b are joined to one oil supply pipe 6 outside the oil sump 3. The suction pipe 5a provided above is provided with a solenoid valve 15. This solenoid valve 15 is provided when the lubricating oil 4 in the oil sump 3 has a normal amount of oil (between oil level 4a and 4b). Is open, the oil level is lowered to 4b or less, and closed when the temperature sensor 13 detects a drop in the oil level due to an increase in the discharge temperature.

In the present embodiment configured as described above, when the operation of the gas compression device P is started, while the oil sump 3 is in the normal amount of oil, both the first and second suction pipes 5a and 5b are used. Lubricating oil 4 is supplied, and the discharge temperature is stable at T ₁ as shown in FIG. Decreases the amount of oil in the oil sump 3 lowers the oil level (4b) Then, the discharge temperature air is mixed into the first suction pipe 5a is gradually increased, the temperature sensor 13 is a constant temperature T ₂ process until it detected as shown in step S ₁ to S ₅ in the flowchart of FIG. 14 is the same as that in the first embodiment (step S ₁ to S ₅ in the flowchart of FIG. 3).

When the discharge temperature detected by the temperature sensor 13 reaches T ₂ , it is determined that the oil level has decreased and an alarm is issued. At the same time, the operation of the gas compression device P is continued and the first suction is performed. closed electromagnetic valve 15 provided in the tube 5a (step S _7), the lubricating oil 4 supplied only from the second suction tube 5b.

In this way, when the amount of oil in the sump 3 decreases and air enters the first suction pipe 5a and the discharge temperature rises, the solenoid valve 15 is maintained while the operation of the gas compression device P is continued. closed, since continued lubricant 4 from the second suction pipe 5b is supplied, the discharge temperature returns normally (step S _8).

15-17 is explanatory drawing which shows the other example of the oil sump of the gas compression apparatus which concerns on this Embodiment. In the figure, the solenoid valve is omitted.
The oil sump 3 in FIG. 15 has the first and second suction pipes 5a and 5b attached to the oil sump 3 at the same height position, and the suction port of the first suction pipe 5a is located in the vicinity of the oil level 4b. The suction port of the second suction pipe 5b is positioned in the vicinity of the oil level 4c, and the electromagnetic valve 15 is provided on the first suction pipe 5a.

In addition, the oil sump 3 in FIG. 16 takes the first and second suction pipes 5a and 5b from the bottom of the oil sump 3, and positions the suction port of the first suction pipe 5a in the vicinity of the oil level 4b. The suction port of the second suction pipe 5b is positioned in the vicinity of the oil level 4c, and the electromagnetic valve 15 is provided on the first suction pipe 5a.
Furthermore, the sump 3 of FIG. 17 is provided with a suction port of the first suction pipe 5a and a suction port of the second suction pipe 5b directly above and below the lower part of the peripheral wall of the sump 3, respectively. 1. A difference is provided in the height position of the suction port of the 1st, 2nd suction pipe 5a, 5b, and the solenoid valve 15 is provided in the 1st suction pipe 5a.
Each oil sump according to this example can be used for the oil sump 3 of the first and second embodiments. However, in this case, the solenoid valve 15 is not provided.

In the above description, the case of a gas compression device including one compressor 1 has been described. However, as in the second embodiment, the present invention is also applied to a gas compression device including a plurality of compressors (for example, three). Embodiments can be implemented.
According to the present embodiment, not only the effects similar to those in the first embodiment can be obtained, but also the supply of the lubricating oil 4 is controlled by the electromagnetic valve 15, so that the seizure of the compressor over a long period of time. It is possible to more reliably prevent damage due to the above and accidents due to abnormal rise in discharge temperature.

[Embodiment 4]
FIG. 18 is a graph showing the relationship between the discharge temperature of the gas compression apparatus according to Embodiment 4 of the present invention and the oil level of the sump, and FIG. 19 is a flowchart for explaining the operation of this embodiment. In addition, the block diagram which shows the cycle structure of a gas compression apparatus is the same as that of the case of Embodiment 4. FIG.

In the present embodiment, the discharge temperature rises due to a drop in the oil level in the sump 3, the temperature sensor 13 detects this, closes the solenoid valve 15 of the first suction pipe 5a, and the second suction pipe. The process (steps S _{1 to} S _{8 in} FIG. 14) until the discharge temperature returns to normal by supplying the lubricating oil 4 only by 5b is the same as that of the fourth embodiment.

In the gas compression device P of the fourth embodiment, when the oil level of the lubricating oil in the sump 3 is further lowered (step S ₉ ) and becomes 4 c or less in FIG. 12 (step S ₁₀ ), the oil Since the second suction pipe 5b of the sump 3 sucks air, the amount of oil sent to the oil supply pipe 6 decreases and the cooling capacity decreases, so that the discharge temperature rises again as shown in FIG. S _11).

In this embodiment, when the temperature sensor 13 detects such an increase in the discharge temperature again, it is determined that the amount of oil in the sump 3 is in a depleted state (step S ₁₂ ), and the compressor 1 is turned on. Control is performed so as not to stop and restart (step S ₁₃ ).
According to the present embodiment, the same effect as in the third embodiment can be obtained.

[Embodiment 5]
FIG. 20 is an explanatory diagram of a sump of the gas compression apparatus according to Embodiment 5 of the present invention. In addition, the block diagram which shows the cycle structure of a gas compression apparatus is as substantially the same as the case of Embodiment 3. FIG.
In the case of the third and fourth embodiments, the case has been shown in which two suction pipes 5a and 5b are provided in the sump 3 and the electromagnetic valve 15 is provided in the upper suction pipe 5a. The oil sump 3 is shown with three or more suction pipes 5 (first, second, and third three suction pipes 5a, 5b, and 5c shown in FIG. And the solenoid valve 15a, 15b is provided on the upper suction pipes 5a, 5b except for the lowermost suction pipe 5c.

  In the present embodiment, when the lubricating oil 4 in the sump 3 is a normal amount of oil, both the solenoid valves 15a and 15b are open, and the lubricating oil 4 is supplied to the compressor 1 from the suction pipes 5a to 5c. The When the amount of oil decreases and the oil level becomes 4b, air enters the suction pipe 5a and the temperature sensor 13 detects an increase in the discharge temperature, the electromagnetic valve 15a of the first suction pipe 5a is closed, and the second The lubricating oil 4 is supplied from the third suction pipes 5b and 5c.

When the oil level further decreases and the oil level becomes 4c, air enters from the second suction pipe 5b and the temperature sensor 13 detects an increase in the discharge temperature, the electromagnetic valve 15b of the second suction pipe 5b is turned on. The lubricating oil 4 is supplied only from the third suction pipe 5c.
When the oil level becomes 4d, air enters from the third suction pipe 5c, and the temperature sensor 13 detects an increase in the discharge temperature, it is determined that the amount of oil in the sump 3 has been exhausted, The compressor 1 is stopped.
According to the present embodiment, substantially the same effect as in the fourth embodiment can be obtained, but the operation of the compressor can be continued for a longer period.

[Embodiment 6]
FIG. 21 is a block diagram showing a cycle configuration of an air-conditioning apparatus according to Embodiment 6 of the present invention. The air-conditioning apparatus according to this embodiment includes the gas compression apparatus according to Embodiment 1. The same parts as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted.
In FIG. 21, AC is an air conditioner in which the gas compression device P is incorporated, and the refrigerant pipe 20 connected to the discharge side of the sump 3 includes an outdoor heat exchanger 21, an expansion part 23 such as an expansion valve, and indoor heat. It is connected to the intake side of the compressor 1 via the exchanger 24. In addition, 22 is an outdoor blower and 25 is an indoor blower.

  In the air conditioning apparatus AC configured as described above, for example, when performing a cooling operation, the refrigerant gas discharged from the compressor 1 passes through a switching valve (not shown) provided in the discharge pipe 9 and is filled with oil. Is separated from the oil by the oil separator 10, sent to the outdoor heat exchanger 21 through the refrigerant pipe 20, condensed, decompressed by the expansion unit 23, evaporated by the indoor heat exchanger 24, and cooled. Return to. In the heating operation, the refrigerant gas discharged from the compressor 1 is switched by the switching valve, flows in the refrigerant pipe 20 in the opposite direction to that in the refrigerant operation, evaporates in the indoor heat exchanger 24, and is heated. I do.

In the present embodiment, the refrigerant gas discharge temperature is always detected by the temperature sensor 13 provided in the discharge pipe 9 of the compressor 1 during the air conditioning operation as described above, and the discharge temperature is equal to or higher than T ₂ (FIG. 3). When it comes to, measures such as issuing an alarm or stopping the operation of the air conditioner AC are taken.
In the above description, the case where the gas compression device P according to Embodiment 1 is incorporated in the air conditioner AC is shown, but the present invention is not limited to this, and gas compression is performed from any of Embodiments 2 to 5. The device P may be incorporated.

According to the present embodiment, a level meter that directly detects the oil level is used to detect a decrease in the oil level of the lubricating oil 4 in the sump 3 of the gas compression device P incorporated in the air conditioner AC. Since the detection is made based on the temperature of the refrigerant gas discharged from the compressor 1, there is no need to consider the level meter failure and maintenance as in the past, and even when sludge is generated in the lubricating oil 4, It is not affected by the oil level detection accuracy.
Moreover, since there is no influence by vibration, it is possible to obtain an air conditioner that has no trouble over a long period of time, such as no problem even if it is mounted on a vehicle that constantly receives vibration.

It is a block diagram which shows the cycle structure of the gas compression apparatus which concerns on Embodiment 1 of this invention. It is explanatory drawing of the oil sump of FIG. It is a graph which shows the relationship between the discharge temperature of compressed gas, and the oil level in a sump. 3 is a flowchart for explaining the operation of the first embodiment. It is explanatory drawing of the other example of the oil sump of Embodiment 1. FIG. It is a block diagram which shows the cycle structure of the gas compression apparatus which concerns on Embodiment 2 of this invention. It is explanatory drawing of the oil distributor of FIG. It is action | operation explanatory drawing of the oil distributor of FIG. It is a graph which shows the relationship between the discharge temperature of compressed gas, and the oil level in a sump. 10 is a flowchart for explaining the operation of the second embodiment. It is a block diagram which shows the cycle structure of the gas compression apparatus which concerns on Embodiment 3 of this invention. It is explanatory drawing of the oil sump of FIG. It is a graph which shows the relationship between the discharge temperature of compressed gas, and the oil level in a sump. 10 is a flowchart for illustrating the operation of the third embodiment. FIG. 10 is an explanatory view showing another example of a sump according to the third embodiment. FIG. 10 is an explanatory view showing another example of a sump according to the third embodiment. FIG. 10 is an explanatory view showing another example of a sump according to the third embodiment. It is a graph which shows the relationship between the discharge temperature of the compressed gas of the gas compression apparatus which concerns on Embodiment 4, and the oil level in a sump. 10 is a flowchart for explaining the operation of the fourth embodiment. It is explanatory drawing of the oil sump of the gas compression apparatus which concerns on Embodiment 5 of this invention. It is a block diagram which shows the cycle structure of the air conditioning apparatus which concerns on Embodiment 6 of this invention.

Explanation of symbols

  1, 1a to 1c Compressor, 3 Oil sump, 4 Lubricating oil, 5, 5a to 5c Suction pipe, 6 Oil supply piping, 6a to 6c Oil distribution piping, 9 Discharge piping, 10 Oil separator, 13 Temperature sensor, 14 Oil content Distributor, 15 solenoid valve, P gas compressor, AC air conditioner.

Claims (8)

In the gas compression apparatus in which the oil mixed in the compressed gas discharged from the compressor is separated by an oil separator and stored in a sump, and the oil in the sump is supplied to the compressor.
A plurality of the compressors are connected in parallel and the discharge pipes are joined to the discharge pipes, and an oil distributor is provided in an oil supply pipe for supplying oil to the compressors, and the oil distributors and the plurality of compressors are When the oil level in the sump is lowered and the compressed gas enters the oil supply pipe, the compressed gas is concentrated in one of the oil pipes. To flow in,
An oil level detection method comprising detecting the oil level of oil in the sump by the temperature of the compressed gas discharged from the compressor. Provided with a temperature sensor for detecting the temperature of the compressed gas flowing through the discharge pipe of the compressor, is connected to the oil supply pipe for supplying oil to the oil sump the compressor, the normal oil level of the suction port oil the suction pipe is provided which is located more downward, by the temperature sensor the temperature rise of the compressed gas discharged from the compressor the compressed gas from entering the suction write pipe senses, oil in the oil sump The oil level detection method according to claim 1, wherein a decrease in the level is detected. The oil sump, suction port positioned below the suction port of the suction tube, the oil level detection according to claim 1 or 2 characterized in that a second suction pipe merges into the oil supply pipe Method. Gas compression in which oil mixed in compressed gas discharged from a compressor is separated by an oil separator and stored in a sump, and the oil in the sump is supplied to the compressor through an oil supply pipe. In the device
Provided with a temperature sensor for detecting the temperature of the compressed gas flowing through the discharge pipe of the compressor, the upper is provided with two suction pipes of different height positions of the inlet merging into the oil supply pipe the oil sump of the suction pipe providing the solenoid valve normally open, the temperature rise of the compressed gas oil level is decreased the compressed gas to the suction pipe of the upper is discharged from the compressor from entering inside the oil sump An oil supply control method comprising: closing the solenoid valve when the temperature sensor detects. Continued even operation After closing the solenoid valve, the oil of claim 4, wherein when the temperature of the compressed gas discharged from the compressor is raised again, characterized in that to stop the operation of said compressor Supply control method. Gas compression in which oil mixed in compressed gas discharged from a compressor is separated by an oil separator and stored in a sump, and the oil in the sump is supplied to the compressor through an oil supply pipe. In the device
Provided with a temperature sensor for detecting the temperature of the compressed gas flowing through the discharge pipe of the compressor, provided with a three or more suction tubes having different height positions of the inlet merging into the oil supply pipe the oil sump Each of the other suction pipes except the lowermost suction pipe is provided with a normally open solenoid valve, the oil level in the sump is lowered, and the compressed gas enters the suction pipe and is discharged from the compressor. wherein the temperature rise of the compressed gas when the temperature sensor detects sequentially closes the electromagnetic valve, when the temperature sensor the temperature rise of the compressed gas the compressed gas to the suction tube at the bottom from entering detects Stops the operation of the compressor. A gas compression apparatus comprising the oil level detection method according to any one of claims 1 to 3 and / or the oil supply control method according to any one of claims 4 to 6 . An air conditioner comprising the gas compression device according to claim 7 .

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