JP2021018020A - Refrigeration apparatus and oil cooling device - Google Patents

Abstract

To provide a refrigeration apparatus capable of suppressing clogging of a heat exchanger in an oil mist atmosphere.SOLUTION: A refrigeration apparatus includes: a refrigerant circuit (RC) having a heat exchanger (3); a casing (11) in which at least the heat exchanger (3) is accommodated and a suction port (12) is provided upstream of the heat exchanger (3); and a filter (13) mounted to the suction port (12) of the casing (11) and having a filtering material bent to form a bellows shape. When air including oil mist is supplied to the heat exchanger (3) via the filter (13), at least a part of an oil component in the air including oil mist is captured by the filter (13).SELECTED DRAWING: Figure 1

Description

The present disclosure relates to a refrigerating apparatus and an oil cooling apparatus using the refrigerating apparatus.

Conventionally, there is an oil cooling device for cooling oil used for cooling a spindle or a motor of a machine tool (see, for example, Japanese Patent Application Laid-Open No. 2019-34397 (Patent Document 1)).

The oil cooling device includes a refrigerant circuit having a condenser and an evaporator, cools the oil by the evaporator, and exhausts heat from the condenser to the outside.

Japanese Unexamined Patent Publication No. 2019-34397

In the above-mentioned conventional oil cooling device, since it is used in the same installation space as a machine tool, air containing oil mist is sucked through a filter and supplied to a condenser, and oil and dust adhere to the condenser. It gets clogged.

Cleaning such a clogged condenser requires removal from the oil chiller, which requires a long time to remove, clean, and install the condenser, increasing maintenance costs and increasing maintenance costs. There is a problem that the down period of the machine tool becomes long and the operating rate decreases.

The present disclosure proposes a refrigerating device capable of suppressing clogging of a heat exchanger in an oil mist atmosphere and an oil cooling device using the refrigerating device.

The refrigeration equipment of the present disclosure is
Refrigerant circuit with heat exchanger and
A housing in which at least the heat exchanger is housed and a suction port is provided on the upstream side of the heat exchanger.
A filter attached to the suction port of the housing and having a filter medium bent in a bellows shape is provided.
When the air containing the oil mist is supplied to the heat exchanger through the filter, at least a part of the oil content in the air containing the oil mist is captured by the filter.

According to the present disclosure, the surface area of the filter attached to the suction port of the housing is increased as compared with the filter having the flat-shaped filter medium because the filter medium is bent in a bellows shape. Therefore, when air containing oil mist is supplied to the heat exchanger through the filter, the filter having a large surface area of the filter medium can retain a large amount of oil and has a life (time until the filter is clogged). Is extended.

Further, in the refrigerating apparatus according to one aspect of the present disclosure,
An oil receiving portion provided below the space between the heat exchanger and the filter,
Guidance route to guide oil from the above oil receiving part and
It is provided with an oil reservoir for accumulating the oil guided by the above guide route.

According to the present disclosure, the oil trapped in the filter flows down, and the oil adhering to the front side of the heat exchanger flows down, and the oil that has flowed down flows down below the space between the heat exchanger and the filter. It is received at the oil receiving part provided in. The oil received in the oil receiving part is guided to the oil reservoir part by the guide path. As a result, the oil adhering to the filter and the heat exchanger can be collectively processed by collecting it in the oil reservoir without polluting the surrounding area with oil.

Further, in the refrigerating apparatus according to one aspect of the present disclosure,
A plurality of plate-shaped fins of the heat exchanger are arranged parallel to each other and along the vertical direction.

According to the present disclosure, it is possible to effectively prevent the oil component adhering to the front surface side of the heat exchanger from smoothly flowing downward and the oil droplets staying between the fins and clogging.

Further, in the refrigerating apparatus according to one aspect of the present disclosure,
The filter is configured to guide oil droplets adhering to the surface of the filter downward.

According to the present disclosure, it is possible to effectively prevent the oil content adhering to the filter from smoothly flowing downward and the oil droplets staying on the filter and clogging the filter.

Further, in the refrigerating apparatus according to one aspect of the present disclosure,
The filter is attached to the suction port of the housing so that the fold of the filter is in the vertical direction.

According to the present disclosure, it is possible to effectively prevent the oil content adhering to the filter from smoothly flowing downward and the oil droplets staying on the filter and clogging the filter.

Further, in the refrigerating apparatus according to one aspect of the present disclosure, the filters are attached to the heat exchanger at intervals.

According to the present disclosure, even if air containing oil mist is supplied to the heat exchanger through the filter and the oil in the air is captured by the filter, the oil captured by the filter is transmitted to the heat exchanger side and moves. Since it cannot be easily done, clogging of the heat exchanger can be suppressed.

Further, in the oil cooling device of the present disclosure,
Equipped with any one of the above refrigeration equipment
The refrigerant circuit of the refrigerating device has a first heat exchanger that functions as a condenser and a second heat exchanger that functions as an evaporator.
The oil is cooled by the second heat exchanger.

According to the present disclosure, it is possible to realize an oil cooling device capable of suppressing clogging of a first heat exchanger that functions as a condenser in an oil mist atmosphere.

It is a schematic block diagram of the oil cooling apparatus using the refrigerating apparatus of 1st Embodiment of this disclosure. It is a perspective view of the oil cooling apparatus of 1st Embodiment. It is a front view of the oil cooling apparatus of 1st Embodiment. It is a figure of the main part of the vertical cross section seen from the IV-IV line of FIG. It is a figure of the main part of the cross section seen from the VV line of FIG. It is a top view of the filter of the oil cooling apparatus of 1st Embodiment. It is a perspective view which shows the structure of the condenser of the oil cooling apparatus of 1st Embodiment. It is a figure which shows the change of the total pressure loss of the filter of the oil cooling apparatus of 1st Embodiment.

Hereinafter, embodiments will be described. In the drawings, the same reference number represents the same part or the corresponding part. In addition, the dimensions on the drawing such as length, width, thickness, and depth are appropriately changed from the actual scale for the purpose of clarifying and simplifying the drawing, and do not represent the actual relative dimensions.

[First Embodiment]
FIG. 1 is a schematic configuration diagram of an oil cooling device 10 using the refrigerating device of the first embodiment of the present disclosure. The oil cooling device 10 cools the hydraulic oil, the lubricating oil, and the cutting fluid (hereinafter referred to as “oil”) of the machine tool 100 while circulating them through the oil tank T. The machine tool 100 is a machine tool such as an NC lathe, a grinding machine, and an NC dedicated machine, and an industrial machine such as a molding machine and a press machine.

As shown in FIG. 1, the oil cooling device 10 of the first embodiment includes a refrigerant circuit RC in which a compressor 1, a condenser 3, an electronic expansion valve EV, and an evaporator 4 are connected in a ring shape, and a refrigerant circuit RC. A four-way switching valve 2 that switches the refrigerant circulation direction from the forward cycle to the reverse cycle, a blower fan 6 that supplies air to the condenser 3, and a control device 50 that controls the refrigerant circuit RC, the four-way switching valve 2, and the blower fan 6. And have. The electronic expansion valve EV is an example of a pressure reducing mechanism. Further, the refrigerant circuit RC has a hot gas bypass pipe L10 and a hot gas bypass valve HGB arranged in the hot gas bypass pipe L10.

The condenser 3 is an example of a first heat exchanger, and the evaporator 4 is an example of a second heat exchanger.

The discharge side of the compressor 1 is connected to the first port 2a of the four-way switching valve 2. The second port 2b of the four-way switching valve 2 is connected to one end of the condenser 3 via the closing valve V1. The other end of the condenser 3 is connected to one end of the electronic expansion valve EV via the closing valve V2.

Further, the other end of the electronic expansion valve EV is connected to one end 4a of the evaporator 4. Further, the other end 4b of the evaporator 4 is connected to the third port 2c of the four-way switching valve 2. Further, the fourth port 2d of the four-way switching valve 2 is connected to the suction side of the compressor 1 via the accumulator 5. Further, one end of the hot gas bypass pipe L10 is connected to one end 4a side of the evaporator 4. The other end of the hot gas bypass pipe L10 is connected to the second port 2b side of the four-way switching valve 2.

Further, the other end of the pipe L1 whose one end is immersed in the oil in the oil tank T is connected to the suction port of the circulation pump P. The discharge port of the circulation pump P is connected to the inflow port 4c of the evaporator 4 via the pipe L2.

Further, one end of the pipe L3 is connected to the outflow port 4d of the evaporator 4, and the other end of the pipe L3 is connected to the inflow port 101 of the machine tool 100. The outflow port 102 of the machine tool 100 and the oil tank T are connected via the pipe L4.

The oil tank T, the evaporator 4, the machine tool 100, and the pipes L1 to L4 form a circulation path for oil to circulate.

The oil cooling device 10 and the circulation path constitute an oil cooling system. In the first embodiment, the oil cooling device 10 is provided with the circulation pump P, but the circulation pump is provided separately from the oil cooling device, and the oil cooling system is configured by the oil cooling device, the circulation pump, and the circulation path. You may.

In the oil cooling device 10, after the refrigerant is recovered in the evaporator 4 by the pump down operation, the condenser 3 is removed from the housing 11 and the condenser 3 is washed. In the pump down operation, the coil of the four-way switching valve 2 is excited so that the refrigerant circulation direction of the refrigerant circuit is reversed.

FIG. 2 is a perspective view of the oil cooling device 10, and FIG. 3 is a front view of the oil cooling device 10. As shown in FIGS. 2 and 3, the oil cooling device 10 includes a vertically long rectangular parallelepiped housing 11. A suction port 12 located on the upstream side of the condenser 3 is provided on one side surface of the housing 11. A filter 13 is attached to the suction port 12. In FIG. 2, reference numeral 14 denotes an air outlet provided on the top surface side of the housing 11.

The refrigerant circuit RC shown in FIG. 1, the four-way switching valve 2, the blower fan 6, and the control device 50 are housed in the housing 11.

The filter 13, the condenser 3, and the blower fan 6 are arranged in the housing 11 in the order of the filter 13, the condenser 3, and the blower fan 6 from the suction port 12 side.

In the oil cooling device 10, the outside air is sucked from the suction port 12 through the filter 13 by the blower fan 6, supplied to the condenser 3, and then discharged from the outlet 14.

FIG. 4 is a view of a main part of a vertical cross section seen from line IV-IV of FIG. 3, and FIG. 5 is a view of a main part of a cross section seen from line VV of FIG. In FIGS. 4 and 5, the filter 13 is attached to the suction port 12 of the housing 11 with a distance D (10 mm in this embodiment) from the condenser 3.

As shown in FIGS. 4 and 5, the housing 11 has a bottom frame 30 that covers the lower side of the housing 11. The bottom frame 30 is guided by an oil receiving portion 31 provided below the space A between the condenser 3 and the filter 13, a guide path 32 for guiding the oil from the oil receiving portion 31, and a guide path 32. It has a concave oil reservoir 33 for accumulating the oil. In this embodiment, the oil receiving portion 31, the guide path 32, and the oil reservoir 33 are integrally formed on the bottom frame 30, but the oil receiving portion, the guide path, and the oil reservoir are provided separately from the bottom frame. May be good.

The filter 13 is attached to the housing 11 using the attachment frame 20. The lower frame portion 22 of the mounting frame 20 is inclined toward the condenser 3 side and downward. Further, since the filter 13 having the filter medium 13a bent in a bellows shape has high rigidity, the distance D between the filter 13 and the condenser 3 can be maintained by fixing the filter 13 to the mounting frame 20.

Further, the filter 13 is configured to guide the oil droplets adhering to the surface of the filter 13 downward. Specifically, the filter 13 having the filter medium 13a bent in a bellows shape shown in FIG. 6 is attached to the suction port 12 of the housing 11 so that the folds are in the vertical direction. The filter 13 is formed by bending a non-woven fabric having a fiber diameter of several μm in a bellows shape. In this embodiment, the crease interval W of the filter medium 13a is set to 2. By providing in the range of mm to 7.0 mm, the filter medium pressure loss and the structural pressure loss are adjusted, and a low pressure loss is realized.

In the filter 13 of the first embodiment, the holding amount is improved by increasing the surface area of the filter medium in the range of 15 times to 45 times as compared with the flat filter, and the life is extended.

The filter 13 of the oil cooling device 10 of the present disclosure is adjacent to each other by using an adhesive on the front and back of a folded piece in which mountain folds and valley folds are alternately formed in order to keep the fold interval W constant. The folding pieces maintain a V-shape. Further, convex portions may be formed on the front and back surfaces of the folding pieces formed by alternately arranging the folds of the mountain folds and the valley folds so that the adjacent folding pieces maintain the V shape. Further, a stabilizer or a separator may be inserted between the folding pieces formed by alternately arranging the folds of the mountain folds and the valley folds so that the adjacent folding pieces maintain the V shape. ..
Further, the filter 13 may be provided with filter frames on all sides in order to maintain the folded shape.

In the oil cooling operation of the oil cooling device 10, the high-pressure gas refrigerant discharged from the compressor 1 flows into the condenser 3 via the four-way switching valve 2 and exchanges heat with the outside air in the condenser 3. By condensing, it becomes a liquid refrigerant. Next, the liquid refrigerant decompressed by the electronic expansion valve EV flows into the evaporator 4 and exchanges heat with the oil to evaporate to become a low-pressure gas refrigerant, which is transferred to the suction side of the compressor 1 via the accumulator 5. go back. As a result, the oil is cooled in the evaporator 4. In this oil cooling operation, the control device 50 controls the rotation frequency of the compressor 1 and the opening degree of the electronic expansion valve EV based on the oil temperature, the room temperature, and the like. In the hot gas bypass valve HGB arranged in the hot gas bypass pipe L10, the cooling capacity at the time of low load is controlled by adjusting the amount of high temperature and high pressure gas supplied to the evaporator 4.

In a conventional oil cooling device, when used in an oil mist atmosphere in an environment where a machine tool is installed, a net-like or roll-shaped filter is attached to the suction port.

In such a conventional oil cooling device, the present inventor sucks air containing oil mist through the filter and supplies it to the condenser, so that the filter pushed by the wind pressure comes into contact with the condenser. The oil and dust trapped by the filter move to the condenser side and stay between the filter and the condenser together with the oil adhering to the condenser side, which causes clogging of the condenser. I found that it is one of the factors.

Therefore, in the oil cooling device 10 using the refrigerating device of the present disclosure, the filter 13 is attached to the suction port 12 of the housing 11 at intervals D with respect to the condenser 3 (heat exchanger). As a result, in the oil cooling device 10 installed in the environment of the oil mist atmosphere, the air containing the oil mist is supplied to the condenser 3 through the filter 13, and the oil content in the air containing the oil mist is supplied to the filter 13. Even if the oil is trapped, the oil trapped in the filter 13 cannot be easily moved to the condenser 3 side, so that clogging of the condenser 3 can be suppressed.

In the refrigerating apparatus having the above configuration, the surface area of the filter 13 attached to the suction port 12 of the housing 11 is increased as compared with the flat-shaped filter 13 because the filter medium 13a is bent in a bellows shape. Therefore, when air containing oil mist is supplied to the condenser 3 via the filter 13, a filter having a large surface area can retain a large amount of oil and has a long life (time until the filter is clogged). Extend.

Further, the oil trapped in the filter 13 flows down, and the oil adhering to the front surface side of the condenser 3 flows down, and the oil that has flowed down flows down below the space A between the condenser 3 and the filter 13. It is received by the provided oil receiving portion 31. The oil received by the oil receiving unit 31 is guided to the oil reservoir 33 by the guide path 32. As a result, the oil content adhering to the filter 13 and the condenser 3 can be collected in the oil reservoir 33 and collectively processed without polluting the periphery of the device with oil.

Further, FIG. 7 shows a state in which the condenser 3 is removed from the housing 11 for cleaning, and as shown in FIG. 7, a plurality of plate-shaped fins 3a of the condenser 3 are parallel to each other and in the vertical direction. It is arranged along. As a result, as shown by the arrow in FIG. 4, the oil component adhering to the front surface side of the condenser 3 smoothly flows downward, so that it is possible to effectively prevent oil droplets from staying between the fins 3a and clogging.

Further, since the filter 13 is configured to guide the oil droplets adhering to the surface of the filter 13 downward, as shown by the arrow in FIG. 4, the oil adhering to the filter 13 smoothly flows downward. It is possible to effectively prevent oil droplets from staying on the filter 13 and clogging the filter 13.

Further, since the filter 13 is attached to the suction port 12 of the housing 11 so that the crease of the filter medium 13a of the filter 13 is in the vertical direction, the oil adhering to the filter 13 smoothly flows downward and the filter 13 It is possible to effectively prevent oil droplets from staying and clogging.

Further, as shown in FIG. 4, the lower frame portion 22 of the mounting frame 20 for mounting the filter 13 on the housing 11 is inclined toward the condenser 3 side and downward, so that the surface of the filter 13 is exposed to the lower frame portion 22. The oil droplets that have adhered and flowed downward are collected below the condenser 3 side along the inclination of the lower frame portion 22 of the mounting frame 20 and adhere to the front surface (suction port 12 side) of the condenser 3. Can be treated with oil droplets that have flowed down.

Further, in the first embodiment, it is possible to realize an oil cooling device 10 capable of suppressing clogging of the condenser 3 (first heat exchanger) in an oil mist atmosphere.

FIG. 8 shows a case where a conventional net filter is used and a case where a conventional net filter and a roll filter (a filter in which a non-woven fabric is wound in a roll) are used in an oil cooling device installed in an environment of an oil mist atmosphere. And, the change of each total pressure loss when the filter 13 of this 1st embodiment is used is shown. In FIG. 8, the horizontal axis is time [Week] (weekly), and the vertical axis is total pressure drop [Pa].
Here, the total pressure loss is
Oil mist concentration: Approximately 1 mg / m ³
It was calculated by the following equation under the conditions of.
Total pressure drop [Pa] = Filter pressure drop [Pa] + Condenser pressure drop [Pa]
Filter pressure loss: Measure the air pressure difference upstream and downstream of the filter 13 with a differential pressure gauge Condenser pressure loss: Measure the air pressure difference upstream and downstream of the condenser 3 with a differential pressure gauge

As shown in FIG. 8, when the conventional net filter was used, the total pressure loss exceeded 50 Pa, which is assumed to be the filter life, in about 5.5 weeks. Further, when the conventional net filter and roll filter were used, the total pressure loss exceeded 50 Pa, which is assumed to be the filter life, in about 3.5 weeks.

On the other hand, when the filter 13 of this embodiment was used, no sharp increase in the total pressure loss was observed even after 13 weeks, and the total pressure loss was less than 50 Pa, which is assumed to be the filter life.

As described above, when the conventional net filter and roll filter are used, the filter needs to be replaced about once every three weeks, whereas the oil cooling device using the freezing device of the first embodiment is used. At 10, the filter may be replaced about once a year.

Further, in this oil cooling device 10, it is necessary to perform cleaning of the condenser 3 (heat exchanger), which has been performed about once every two years, for a long period of time (7 years) or longer than the product life of the oil cooling device 10. Absent.

Therefore, the refrigerating apparatus 10 capable of suppressing clogging of the heat exchanger in an oil mist atmosphere can reduce the cost of maintenance work and suppress the decrease in the operating rate of the machine tool 100.

[Second Embodiment]
It is a liquid cooling device using the refrigerating device of the second embodiment of the present disclosure. This liquid cooling device is used in an oil mist atmosphere, and the cutting fluid is cooled by a refrigerating device having the same configuration as the refrigerating device used in the oil cooling device 10 of the first embodiment.

The liquid cooling device of the second embodiment has the same effect as the oil cooling device 10 of the first embodiment.

In the first and second embodiments, an oil cooling device 10 using a refrigerating device for cooling the oil (hydraulic oil or lubricating oil) of the machine tool 100 and a liquid cooling device using a refrigerating device for cooling the cutting fluid. However, the refrigerating device of the present invention may be applied to a liquid cooling device for cooling other liquids.

[Third Embodiment]
It is an air conditioner as an example of the refrigerating apparatus of the third embodiment of the present disclosure. This air conditioner is used in an oil mist atmosphere, and at least one of cooling and heating is air-conditioned by a refrigerating device having the same configuration as the refrigerating device used in the oil cooling device 10 of the first embodiment.

The air conditioner of the third embodiment has the same effect as the oil cooling device 10 of the first embodiment.

Further, in the first to third embodiments, the refrigerating device for cooling oil (hydraulic oil and lubricating oil), the refrigerating device for cooling cutting fluid, and the air conditioner have been described, but they are used in an oil mist atmosphere. The present invention may be applied to a refrigerating apparatus having the above configuration. In this case, the heat exchanger in which the air containing the oil mist is sucked in and supplied through the filter may be a heat exchanger that functions as a condenser or a heat exchanger that functions as an evaporator. May be good.

Although the specific embodiments of the present disclosure have been described, the present disclosure is not limited to the above-mentioned first to third embodiments, and various modifications can be made within the scope of the present disclosure.

1 ... Compressor 2 ... Four-way switching valve 3 ... Condenser (first heat exchanger)
4 ... Evaporator (second heat exchanger)
5 ... Accumulator 6 ... Blower fan 10 ... Oil cooling device 11 ... Housing 12 ... Suction port 13 ... Filter 13a ... Filter material 14 ... Air outlet 20 ... Mounting frame 21 ... Upper frame part 22 ... Lower frame part 30 ... Bottom frame 31 ... Oil receiving part 32 ... Guide path 33 ... Oil reservoir 50 ... Control device 100 ... Machine EV ... Electronic expansion valve HGB ... Hot gas pipe pass valve L1, L2, L3, L4 ... Piping L10 ... Hot gas pipe pass piping P ... Circulation Pump RC ... Refrigerant circuit T ... Oil tank V1, V2 ... Closed valve

The present disclosure relates to a refrigerating apparatus and an oil cooling apparatus using the refrigerating apparatus.

Conventionally, there is an oil cooling device for cooling oil used for cooling a spindle or a motor of a machine tool (see, for example, Japanese Patent Application Laid-Open No. 2019-34397 (Patent Document 1)).

The oil cooling device includes a refrigerant circuit having a condenser and an evaporator, cools the oil by the evaporator, and exhausts heat from the condenser to the outside.

Japanese Unexamined Patent Publication No. 2019-34397

In the above-mentioned conventional oil cooling device, since it is used in the same installation space as a machine tool, air containing oil mist is sucked through a filter and supplied to a condenser, and oil and dust adhere to the condenser. It gets clogged.

Cleaning such a clogged condenser requires removal from the oil chiller, which requires a long time to remove, clean, and install the condenser, increasing maintenance costs and increasing maintenance costs. There is a problem that the down period of the machine tool becomes long and the operating rate decreases.

The present disclosure proposes a refrigerating device capable of suppressing clogging of a heat exchanger in an oil mist atmosphere and an oil cooling device using the refrigerating device.

The refrigeration equipment of the present disclosure is
Refrigerant circuit with heat exchanger and
A housing in which at least the heat exchanger is housed and a suction port is provided on the upstream side of the heat exchanger.
A filter attached to the suction port of the housing and having a filter medium bent in a bellows shape is provided.
When the air containing the oil mist is supplied to the heat exchanger through the filter, at least a part of the oil content in the air containing the oil mist is captured by the filter.

According to the present disclosure, the surface area of the filter attached to the suction port of the housing is increased as compared with the filter having the flat-shaped filter medium because the filter medium is bent in a bellows shape. Therefore, when air containing oil mist is supplied to the heat exchanger through the filter, the filter having a large surface area of the filter medium can retain a large amount of oil and has a life (time until the filter is clogged). Is extended.
In addition, the refrigeration equipment of the present disclosure is
Refrigerant circuit with heat exchanger and
A housing in which at least the heat exchanger is housed and a suction port is provided on the upstream side of the heat exchanger.
A filter attached to the suction port of the housing and having a filter medium bent in a bellows shape,
An oil receiving portion provided below the space between the heat exchanger and the filter.
With
When the air containing the oil mist is supplied to the heat exchanger through the filter, at least a part of the oil content in the air containing the oil mist is captured by the filter, and the oil receiving portion is subjected to the above. It is characterized in that it receives the oil that is trapped by the filter and flows down, and the oil that adheres to the front side of the heat exchanger and flows down.
According to the present disclosure, the surface area of the filter attached to the suction port of the housing is increased as compared with the filter having the flat-shaped filter medium because the filter medium is bent in a bellows shape. Therefore, when air containing oil mist is supplied to the heat exchanger through the filter, the filter having a large surface area of the filter medium can retain a large amount of oil and has a life (time until the filter is clogged). Is extended.

Further, in the refrigerating apparatus according to one aspect of the present disclosure,
An oil receiving portion provided below the space between the heat exchanger and the filter,
Guidance route to guide oil from the above oil receiving part and
It is provided with an oil reservoir for accumulating the oil guided by the above guide route.

According to the present disclosure, the oil trapped in the filter flows down, and the oil adhering to the front side of the heat exchanger flows down, and the oil that has flowed down flows down below the space between the heat exchanger and the filter. It is received at the oil receiving part provided in. The oil received in the oil receiving part is guided to the oil reservoir part by the guide path. As a result, the oil adhering to the filter and the heat exchanger can be collectively processed by collecting it in the oil reservoir without polluting the surrounding area with oil.

Further, in the refrigerating apparatus according to one aspect of the present disclosure,
A plurality of plate-shaped fins of the heat exchanger are arranged parallel to each other and along the vertical direction.

According to the present disclosure, it is possible to effectively prevent the oil component adhering to the front surface side of the heat exchanger from smoothly flowing downward and the oil droplets staying between the fins and clogging.

Further, in the refrigerating apparatus according to one aspect of the present disclosure,
The filter is configured to guide oil droplets adhering to the surface of the filter downward.

According to the present disclosure, it is possible to effectively prevent the oil content adhering to the filter from smoothly flowing downward and the oil droplets staying on the filter and clogging the filter.

Further, in the refrigerating apparatus according to one aspect of the present disclosure,
The filter is attached to the suction port of the housing so that the fold of the filter is in the vertical direction.

According to the present disclosure, it is possible to effectively prevent the oil content adhering to the filter from smoothly flowing downward and the oil droplets staying on the filter and clogging the filter.

Further, in the refrigerating apparatus according to one aspect of the present disclosure, the filters are attached to the heat exchanger at intervals.

According to the present disclosure, even if air containing oil mist is supplied to the heat exchanger through the filter and the oil in the air is captured by the filter, the oil captured by the filter is transmitted to the heat exchanger side and moves. Since it cannot be easily done, clogging of the heat exchanger can be suppressed.

Further, in the oil cooling device of the present disclosure,
Equipped with any one of the above refrigeration equipment
The refrigerant circuit of the refrigerating device has a first heat exchanger that functions as a condenser and a second heat exchanger that functions as an evaporator.
The oil is cooled by the second heat exchanger.

According to the present disclosure, it is possible to realize an oil cooling device capable of suppressing clogging of a first heat exchanger that functions as a condenser in an oil mist atmosphere.

It is a schematic block diagram of the oil cooling apparatus using the refrigerating apparatus of 1st Embodiment of this disclosure. It is a perspective view of the oil cooling apparatus of 1st Embodiment. It is a front view of the oil cooling apparatus of 1st Embodiment. It is a figure of the main part of the vertical cross section seen from the IV-IV line of FIG. It is a figure of the main part of the cross section seen from the VV line of FIG. It is a top view of the filter of the oil cooling apparatus of 1st Embodiment. It is a perspective view which shows the structure of the condenser of the oil cooling apparatus of 1st Embodiment. It is a figure which shows the change of the total pressure loss of the filter of the oil cooling apparatus of 1st Embodiment.

Hereinafter, embodiments will be described. In the drawings, the same reference number represents the same part or the corresponding part. In addition, the dimensions on the drawing such as length, width, thickness, and depth are appropriately changed from the actual scale for the purpose of clarifying and simplifying the drawing, and do not represent the actual relative dimensions.

[First Embodiment]
FIG. 1 is a schematic configuration diagram of an oil cooling device 10 using the refrigerating device of the first embodiment of the present disclosure. The oil cooling device 10 cools the hydraulic oil, the lubricating oil, and the cutting fluid (hereinafter referred to as “oil”) of the machine tool 100 while circulating them through the oil tank T. The machine tool 100 is a machine tool such as an NC lathe, a grinding machine, and an NC dedicated machine, and an industrial machine such as a molding machine and a press machine.

As shown in FIG. 1, the oil cooling device 10 of the first embodiment includes a refrigerant circuit RC in which a compressor 1, a condenser 3, an electronic expansion valve EV, and an evaporator 4 are connected in a ring shape, and a refrigerant circuit RC. A four-way switching valve 2 that switches the refrigerant circulation direction from the forward cycle to the reverse cycle, a blower fan 6 that supplies air to the condenser 3, and a control device 50 that controls the refrigerant circuit RC, the four-way switching valve 2, and the blower fan 6. And have. The electronic expansion valve EV is an example of a pressure reducing mechanism. Further, the refrigerant circuit RC has a hot gas bypass pipe L10 and a hot gas bypass valve HGB arranged in the hot gas bypass pipe L10.

The condenser 3 is an example of a first heat exchanger, and the evaporator 4 is an example of a second heat exchanger.

The discharge side of the compressor 1 is connected to the first port 2a of the four-way switching valve 2. The second port 2b of the four-way switching valve 2 is connected to one end of the condenser 3 via the closing valve V1. The other end of the condenser 3 is connected to one end of the electronic expansion valve EV via the closing valve V2.

Further, the other end of the electronic expansion valve EV is connected to one end 4a of the evaporator 4. Further, the other end 4b of the evaporator 4 is connected to the third port 2c of the four-way switching valve 2. Further, the fourth port 2d of the four-way switching valve 2 is connected to the suction side of the compressor 1 via the accumulator 5. Further, one end of the hot gas bypass pipe L10 is connected to one end 4a side of the evaporator 4. The other end of the hot gas bypass pipe L10 is connected to the second port 2b side of the four-way switching valve 2.

Further, the other end of the pipe L1 whose one end is immersed in the oil in the oil tank T is connected to the suction port of the circulation pump P. The discharge port of the circulation pump P is connected to the inflow port 4c of the evaporator 4 via the pipe L2.

Further, one end of the pipe L3 is connected to the outflow port 4d of the evaporator 4, and the other end of the pipe L3 is connected to the inflow port 101 of the machine tool 100. The outflow port 102 of the machine tool 100 and the oil tank T are connected via the pipe L4.

The oil tank T, the evaporator 4, the machine tool 100, and the pipes L1 to L4 form a circulation path for oil to circulate.

The oil cooling device 10 and the circulation path constitute an oil cooling system. In the first embodiment, the oil cooling device 10 is provided with the circulation pump P, but the circulation pump is provided separately from the oil cooling device, and the oil cooling system is configured by the oil cooling device, the circulation pump, and the circulation path. You may.

In the oil cooling device 10, after the refrigerant is recovered in the evaporator 4 by the pump down operation, the condenser 3 is removed from the housing 11 and the condenser 3 is washed. In the pump down operation, the coil of the four-way switching valve 2 is excited so that the refrigerant circulation direction of the refrigerant circuit is reversed.

FIG. 2 is a perspective view of the oil cooling device 10, and FIG. 3 is a front view of the oil cooling device 10. As shown in FIGS. 2 and 3, the oil cooling device 10 includes a vertically long rectangular parallelepiped housing 11. A suction port 12 located on the upstream side of the condenser 3 is provided on one side surface of the housing 11. A filter 13 is attached to the suction port 12. In FIG. 2, reference numeral 14 denotes an air outlet provided on the top surface side of the housing 11.

The refrigerant circuit RC shown in FIG. 1, the four-way switching valve 2, the blower fan 6, and the control device 50 are housed in the housing 11.

The filter 13, the condenser 3, and the blower fan 6 are arranged in the housing 11 in the order of the filter 13, the condenser 3, and the blower fan 6 from the suction port 12 side.

In the oil cooling device 10, the outside air is sucked from the suction port 12 through the filter 13 by the blower fan 6, supplied to the condenser 3, and then discharged from the outlet 14.

FIG. 4 is a view of a main part of a vertical cross section seen from line IV-IV of FIG. 3, and FIG. 5 is a view of a main part of a cross section seen from line VV of FIG. In FIGS. 4 and 5, the filter 13 is attached to the suction port 12 of the housing 11 with a distance D (10 mm in this embodiment) from the condenser 3.

As shown in FIGS. 4 and 5, the housing 11 has a bottom frame 30 that covers the lower side of the housing 11. The bottom frame 30 is guided by an oil receiving portion 31 provided below the space A between the condenser 3 and the filter 13, a guide path 32 for guiding the oil from the oil receiving portion 31, and a guide path 32. It has a concave oil reservoir 33 for accumulating the oil. In this embodiment, the oil receiving portion 31, the guide path 32, and the oil reservoir 33 are integrally formed on the bottom frame 30, but the oil receiving portion, the guide path, and the oil reservoir are provided separately from the bottom frame. May be good.

The filter 13 is attached to the housing 11 using the attachment frame 20. The lower frame portion 22 of the mounting frame 20 is inclined toward the condenser 3 side and downward. Further, since the filter 13 having the filter medium 13a bent in a bellows shape has high rigidity, the distance D between the filter 13 and the condenser 3 can be maintained by fixing the filter 13 to the mounting frame 20.

Further, the filter 13 is configured to guide the oil droplets adhering to the surface of the filter 13 downward. Specifically, the filter 13 having the filter medium 13a bent in a bellows shape shown in FIG. 6 is attached to the suction port 12 of the housing 11 so that the folds are in the vertical direction. The filter 13 is formed by bending a non-woven fabric having a fiber diameter of several μm in a bellows shape. In this embodiment, the crease interval W of the filter medium 13a is set to 2. By providing in the range of mm to 7.0 mm, the filter medium pressure loss and the structural pressure loss are adjusted, and a low pressure loss is realized.

In the filter 13 of the first embodiment, the holding amount is improved by increasing the surface area of the filter medium in the range of 15 times to 45 times as compared with the flat filter, and the life is extended.

The filter 13 of the oil cooling device 10 of the present disclosure is adjacent to each other by using an adhesive on the front and back of a folded piece in which mountain folds and valley folds are alternately formed in order to keep the fold interval W constant. The folding pieces maintain a V-shape. Further, convex portions may be formed on the front and back surfaces of the folding pieces formed by alternately arranging the folds of the mountain folds and the valley folds so that the adjacent folding pieces maintain the V shape. Further, a stabilizer or a separator may be inserted between the folding pieces formed by alternately arranging the folds of the mountain folds and the valley folds so that the adjacent folding pieces maintain the V shape. ..
Further, the filter 13 may be provided with filter frames on all sides in order to maintain the folded shape.

In the oil cooling operation of the oil cooling device 10, the high-pressure gas refrigerant discharged from the compressor 1 flows into the condenser 3 via the four-way switching valve 2 and exchanges heat with the outside air in the condenser 3. By condensing, it becomes a liquid refrigerant. Next, the liquid refrigerant decompressed by the electronic expansion valve EV flows into the evaporator 4 and exchanges heat with the oil to evaporate to become a low-pressure gas refrigerant, which is transferred to the suction side of the compressor 1 via the accumulator 5. go back. As a result, the oil is cooled in the evaporator 4. In this oil cooling operation, the control device 50 controls the rotation frequency of the compressor 1 and the opening degree of the electronic expansion valve EV based on the oil temperature, the room temperature, and the like. In the hot gas bypass valve HGB arranged in the hot gas bypass pipe L10, the cooling capacity at the time of low load is controlled by adjusting the amount of high temperature and high pressure gas supplied to the evaporator 4.

In a conventional oil cooling device, when used in an oil mist atmosphere in an environment where a machine tool is installed, a net-like or roll-shaped filter is attached to the suction port.

In such a conventional oil cooling device, the present inventor sucks air containing oil mist through the filter and supplies it to the condenser, so that the filter pushed by the wind pressure comes into contact with the condenser. The oil and dust trapped by the filter move to the condenser side and stay between the filter and the condenser together with the oil adhering to the condenser side, which causes clogging of the condenser. I found that it is one of the factors.

Therefore, in the oil cooling device 10 using the refrigerating device of the present disclosure, the filter 13 is attached to the suction port 12 of the housing 11 at intervals D with respect to the condenser 3 (heat exchanger). As a result, in the oil cooling device 10 installed in the environment of the oil mist atmosphere, the air containing the oil mist is supplied to the condenser 3 through the filter 13, and the oil content in the air containing the oil mist is supplied to the filter 13. Even if the oil is trapped, the oil trapped in the filter 13 cannot be easily moved to the condenser 3 side, so that clogging of the condenser 3 can be suppressed.

In the refrigerating apparatus having the above configuration, the surface area of the filter 13 attached to the suction port 12 of the housing 11 is increased as compared with the flat-shaped filter 13 because the filter medium 13a is bent in a bellows shape. Therefore, when air containing oil mist is supplied to the condenser 3 via the filter 13, a filter having a large surface area can retain a large amount of oil and has a long life (time until the filter is clogged). Extend.

Further, the oil trapped in the filter 13 flows down, and the oil adhering to the front surface side of the condenser 3 flows down, and the oil that has flowed down flows down below the space A between the condenser 3 and the filter 13. It is received by the provided oil receiving portion 31. The oil received by the oil receiving unit 31 is guided to the oil reservoir 33 by the guide path 32. As a result, the oil content adhering to the filter 13 and the condenser 3 can be collected in the oil reservoir 33 and collectively processed without polluting the periphery of the device with oil.

Further, FIG. 7 shows a state in which the condenser 3 is removed from the housing 11 for cleaning, and as shown in FIG. 7, a plurality of plate-shaped fins 3a of the condenser 3 are parallel to each other and in the vertical direction. It is arranged along. As a result, as shown by the arrow in FIG. 4, the oil component adhering to the front surface side of the condenser 3 smoothly flows downward, so that it is possible to effectively prevent oil droplets from staying between the fins 3a and clogging.

Further, since the filter 13 is configured to guide the oil droplets adhering to the surface of the filter 13 downward, as shown by the arrow in FIG. 4, the oil adhering to the filter 13 smoothly flows downward. It is possible to effectively prevent oil droplets from staying on the filter 13 and clogging the filter 13.

Further, since the filter 13 is attached to the suction port 12 of the housing 11 so that the crease of the filter medium 13a of the filter 13 is in the vertical direction, the oil adhering to the filter 13 smoothly flows downward and the filter 13 It is possible to effectively prevent oil droplets from staying and clogging.

Further, as shown in FIG. 4, the lower frame portion 22 of the mounting frame 20 for mounting the filter 13 on the housing 11 is inclined toward the condenser 3 side and downward, so that the surface of the filter 13 is exposed to the lower frame portion 22. The oil droplets that have adhered and flowed downward are collected below the condenser 3 side along the inclination of the lower frame portion 22 of the mounting frame 20 and adhere to the front surface (suction port 12 side) of the condenser 3. Can be treated with oil droplets that have flowed down.

Further, in the first embodiment, it is possible to realize an oil cooling device 10 capable of suppressing clogging of the condenser 3 (first heat exchanger) in an oil mist atmosphere.

FIG. 8 shows a case where a conventional net filter is used and a case where a conventional net filter and a roll filter (a filter in which a non-woven fabric is wound in a roll) are used in an oil cooling device installed in an environment of an oil mist atmosphere. And, the change of each total pressure loss when the filter 13 of this 1st embodiment is used is shown. In FIG. 8, the horizontal axis is time [Week] (weekly), and the vertical axis is total pressure drop [Pa].
Here, the total pressure loss is
Oil mist concentration: Approximately 1 mg / m ³
It was calculated by the following equation under the conditions of.
Total pressure drop [Pa] = Filter pressure drop [Pa] + Condenser pressure drop [Pa]
Filter pressure loss: Measure the air pressure difference upstream and downstream of the filter 13 with a differential pressure gauge Condenser pressure loss: Measure the air pressure difference upstream and downstream of the condenser 3 with a differential pressure gauge

As shown in FIG. 8, when the conventional net filter was used, the total pressure loss exceeded 50 Pa, which is assumed to be the filter life, in about 5.5 weeks. Further, when the conventional net filter and roll filter were used, the total pressure loss exceeded 50 Pa, which is assumed to be the filter life, in about 3.5 weeks.

On the other hand, when the filter 13 of this embodiment was used, no sharp increase in the total pressure loss was observed even after 13 weeks, and the total pressure loss was less than 50 Pa, which is assumed to be the filter life.

As described above, when the conventional net filter and roll filter are used, the filter needs to be replaced about once every three weeks, whereas the oil cooling device using the freezing device of the first embodiment is used. At 10, the filter may be replaced about once a year.

Further, in this oil cooling device 10, it is necessary to perform cleaning of the condenser 3 (heat exchanger), which has been performed about once every two years, for a long period of time (7 years) or longer than the product life of the oil cooling device 10. Absent.

Therefore, the refrigerating apparatus 10 capable of suppressing clogging of the heat exchanger in an oil mist atmosphere can reduce the cost of maintenance work and suppress the decrease in the operating rate of the machine tool 100.

[Second Embodiment]
It is a liquid cooling device using the refrigerating device of the second embodiment of the present disclosure. This liquid cooling device is used in an oil mist atmosphere, and the cutting fluid is cooled by a refrigerating device having the same configuration as the refrigerating device used in the oil cooling device 10 of the first embodiment.

The liquid cooling device of the second embodiment has the same effect as the oil cooling device 10 of the first embodiment.

In the first and second embodiments, an oil cooling device 10 using a refrigerating device for cooling the oil (hydraulic oil or lubricating oil) of the machine tool 100 and a liquid cooling device using a refrigerating device for cooling the cutting fluid. However, the refrigerating device of the present invention may be applied to a liquid cooling device for cooling other liquids.

[Third Embodiment]
It is an air conditioner as an example of the refrigerating apparatus of the third embodiment of the present disclosure. This air conditioner is used in an oil mist atmosphere, and at least one of cooling and heating is air-conditioned by a refrigerating device having the same configuration as the refrigerating device used in the oil cooling device 10 of the first embodiment.

The air conditioner of the third embodiment has the same effect as the oil cooling device 10 of the first embodiment.

Further, in the first to third embodiments, the refrigerating device for cooling oil (hydraulic oil and lubricating oil), the refrigerating device for cooling cutting fluid, and the air conditioner have been described, but they are used in an oil mist atmosphere. The present invention may be applied to a refrigerating apparatus having the above configuration. In this case, the heat exchanger in which the air containing the oil mist is sucked in and supplied through the filter may be a heat exchanger that functions as a condenser or a heat exchanger that functions as an evaporator. May be good.

Although the specific embodiments of the present disclosure have been described, the present disclosure is not limited to the above-mentioned first to third embodiments, and various modifications can be made within the scope of the present disclosure.

1 ... Compressor 2 ... Four-way switching valve 3 ... Condenser (first heat exchanger)
4 ... Evaporator (second heat exchanger)
5 ... Accumulator 6 ... Blower fan 10 ... Oil cooling device 11 ... Housing 12 ... Suction port 13 ... Filter 13a ... Filter material 14 ... Air outlet 20 ... Mounting frame 21 ... Upper frame part 22 ... Lower frame part 30 ... Bottom frame 31 ... Oil receiving part 32 ... Guide path 33 ... Oil reservoir 50 ... Control device 100 ... Machine EV ... Electronic expansion valve HGB ... Hot gas pipe pass valve L1, L2, L3, L4 ... Piping L10 ... Hot gas pipe pass piping P ... Circulation Pump RC ... Refrigerant circuit T ... Oil tank V1, V2 ... Closed valve

Claims (7)

A refrigerant circuit (RC) having a heat exchanger (3) and
A housing (11) in which at least the heat exchanger (3) is housed and a suction port (12) is provided on the upstream side of the heat exchanger (3).
It is provided with a filter (13) attached to the suction port (12) of the housing (11) and having a filter medium (13a) bent in a bellows shape.
When the air containing the oil mist is supplied to the heat exchanger (3) through the filter (13), at least a part of the oil in the air containing the oil mist is captured by the filter (13). A freezing device characterized by that. In the refrigerating apparatus according to claim 1,
An oil receiving portion (31) provided below the space between the heat exchanger (3) and the filter (13), and
A guide path (32) for guiding oil from the oil receiving portion (31) and
A refrigerating apparatus provided with an oil reservoir (33) for accumulating oil guided by the guide path (32). In the refrigerating apparatus according to claim 1 or 2.
A refrigerating apparatus characterized in that a plurality of plate-shaped fins (3a) of the heat exchanger (3) are arranged parallel to each other and along the vertical direction. In the refrigerating apparatus according to any one of claims 1 to 3,
A refrigerating apparatus characterized in that the filter (13) is configured to guide oil droplets adhering to the surface of the filter (13) downward. In the refrigerating apparatus according to claim 4,
A freezing device characterized in that the filter (13) is attached to the suction port (12) of the housing (11) so that the folds of the filter medium (13a) are in the vertical direction. In the refrigerating apparatus according to any one of claims 1 to 5,
The filter (13) is a refrigerating apparatus characterized in that it is attached to the heat exchanger (3) at intervals. The refrigerating apparatus according to any one of claims 1 to 6 is provided.
The refrigerant circuit (RC) of the refrigerating device has a first heat exchanger (3) that functions as a condenser and a second heat exchanger (3) that functions as an evaporator.
An oil cooling device characterized in that oil is cooled by the second heat exchanger (3).

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