JP2013071220A - Production line system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a production line system capable of continuing the cooling of an object even if a cooling interlock mechanism is actuated and high in energy efficiency.SOLUTION: On a cooling side of a heat pump 20 in a production line system 10, a cutting fluid is cooled with cold water that circulates a cooling system, and the cold water is cooled by the heat pump 20. When the cold water reaches a predetermined lower limit cooling value or lower to turn on a cooing interlock, the cooling of the cold water by the heat pump 20 is stopped, and when there is a request for cooling the cutting fluid, a cold water pump 32 is actuated to circulate the cold water in the cooling system.

Description

  The present invention relates to a production line system including a cooling process step of cooling at least a cooling target using a heat pump cycle.

  Conventionally, various technologies have been developed in terms of effective use of energy, but in recent years, further energy saving has been demanded based on environmental issues. Therefore, there is an increasing demand for energy efficient production line systems. Therefore, in order to increase energy efficiency, a production line system using a heat pump that simultaneously performs heating and cooling by exchanging heat of a heating target and a cooling target has been proposed.

  As this type of production line system, for example, there is a paint drying apparatus described in Patent Document 1. In this paint drying device, the heating medium for generating hot air and the cooling medium for generating cold air are collectively cooled by a heat pump, and the waste water from the factory, hot water from a separate heat pump, exhaust from each furnace, etc. Heat exchange is performed between the side heating medium) and the cooling medium. Then, by applying the cooling side heating medium to the refrigerant, it is possible to prevent overcooling according to the amount of heating, and to ensure an extremely efficient and stable operation of the heat pump.

  Here, in general, including the above-described devices, in the heat pump, when the temperature of the cooling medium for cooling the object to be cooled falls below a set value, cooling by the heat pump cycle is performed to prevent the heat exchanger provided in the heat pump from freezing. A mechanism (cooling interlock mechanism) for forcibly stopping the cooling of the target is provided. Then, when the cooling medium temperature rises to a specified value, cooling of the cooling target by the heat pump cycle is resumed. Even when the cooling interlock mechanism is activated, the heating target is heated by the heat pump cycle according to the heating request.

JP 2010-151437 A

  However, in the apparatus provided with the cooling interlock mechanism, including the apparatus described in Patent Document 1 described above, when the cooling interlock mechanism is activated, the temperature of the cooling medium is regulated even if there is a cooling request for the cooling target. There is a problem that the cooling target is not cooled by the heat pump cycle until the value is increased. Therefore, the cooling target cannot be efficiently cooled.

  Therefore, the present invention was made to solve the above-described problems, and an energy-efficient production line system capable of continuously cooling an object to be cooled even when a cooling interlock mechanism is activated. The purpose is to provide.

  One form of this invention made | formed in order to solve the said subject WHEREIN: In the production line system which has at least the cooling process process which cools the cooling object by a heat pump cycle, in the said cooling process process, the said cooling is carried out with the refrigerant | coolant which circulates in a cooling system. When the target is cooled, the refrigerant is cooled by the heat pump cycle, and when the refrigerant falls below a predetermined lower limit value, the cooling of the refrigerant by the heat pump cycle is stopped, and when there is a cooling request for the cooling target The refrigerant is circulated through the cooling system.

In this production line system, when the refrigerant falls below a predetermined lower limit value, the cooling process step by the heat pump cycle is stopped. That is, the cooling interlock mechanism is operated to stop the cooling of the refrigerant by heat exchange in the heat pump cycle.
Here, when there is a cooling request to be cooled, the refrigerant is circulated in the cooling system. That is, the refrigerant is not cooled by heat exchange, but the refrigerant is circulated in the cooling system. At this time, since the refrigerant is not more than a predetermined lower limit and has a low temperature (about several degrees Celsius), the object to be cooled can be cooled with the refrigerant by circulating the low-temperature refrigerant in the cooling system. Therefore, even if the cooling interlock mechanism is activated, the cooling target can be continuously cooled.
Moreover, the temperature rise of a refrigerant | coolant can be accelerated | stimulated by circulating a low-temperature refrigerant | coolant to a cooling system. Therefore, the time from the cooling interlock state to the normal operation can be shortened.
By these things, the cooling object can be efficiently cooled and a production line system with high energy efficiency can be realized.

  In the production line system described above, in the cooling processing step, the refrigerant cooled by heat exchange with the heat pump refrigerant is circulated to the cooling system by a refrigerant pump, and the cooling target is cooled by the refrigerant circulating in the cooling system. When the refrigerant falls below a predetermined lower limit value, the cooling of the refrigerant by the heat pump refrigerant is stopped, and when there is a cooling request for the cooling target, the refrigerant pump is operated to cool the refrigerant. It only has to be circulated in the system.

  As described above, when the refrigerant becomes equal to or lower than the predetermined lower limit value, the cooling interlock mechanism is operated to stop the cooling of the refrigerant by heat exchange with the heat pump refrigerant (heat pump), while there is a cooling request for the cooling target. When the cooling pump is operated and the refrigerant is circulated through the cooling system, the cooling target can be continuously cooled even when the cooling interlock mechanism is operated. Therefore, the cooling target can be efficiently cooled, and a production line system with high energy efficiency can be realized.

  In the production line system described above, the object to be cooled is coolant stored in a coolant tank for supplying to a machining machine that processes a workpiece, and it is preferable that a plurality of the coolant tanks are installed.

  Since the coolant is contaminated by cutting or the like due to machining, the heat exchange rate with the coolant is likely to decrease, and the coolant is likely to be overcooled. In addition, when the number of coolant tanks that require cooling decreases (for example, when only one of the installed units issues a cooling request), the amount of heat exchanged (the amount of heat received from the coolant) decreases, so that the amount of refrigerant is excessive. Easy to cool. Therefore, in such a production line system, the number of times that the cooling interlock mechanism operates tends to increase, which is suitable for applying the present invention.

  In the production line system described above, it has a heat treatment process for heating the object to be heated, and the heat treatment process and the cooling treatment process are performed by one heat pump, and the heat pump is a cooling / heating simultaneous operation and a cooling single operation. Or it is preferable that it is a 3 mode type heat pump in which heating independent operation is possible.

  By performing the heat treatment step and the cooling treatment step with a single heat pump in this way, heating and cooling can be performed using heat deprived or deprived from each other as a heat source, and energy efficiency is extremely high. It can be. Since the three-mode heat pump is used, it is possible to flexibly cope with each process appropriately by switching the operation state regardless of how the cooling load or the heating load appears or changes.

  When the three-mode heat pump is used in this way, when the refrigerant is equal to or lower than a predetermined lower limit value, the heat pump, when there is a heating request for the heating target, regardless of the cooling request for the cooling target. When the single heating operation is performed and there is a cooling request for the cooling target, the refrigerant pump may be operated to circulate the refrigerant to the cooling system.

  In this way, each process can be processed flexibly and appropriately according to the state of the cooling load and heating load, and even if the cooling interlock mechanism is activated, cooling of the object to be cooled continues. Can be done. Therefore, energy efficiency can be further increased.

  In the production line system described above, the heating target is preferably a cleaning liquid that cleans the workpiece before or after the workpiece is processed.

By adopting such a configuration, the heat treatment step of the cleaning liquid can be adjacent to or after the cooling treatment step in the machining machine, and the cooling treatment step and the heat treatment step can be made a series. . As a result, the distance from the heat pump to the cooling treatment step or the heat treatment step is shortened, the cost is reduced by shortening the piping and the like, transmission loss is reduced, and further energy saving can be achieved.
In addition, the heating and cooling system can be completed for each series of processing lines in the factory, and the flexibility can be made extremely good.
And since a heat pump is used in a series of processing lines, cooling and heating are always required at the same time during production, so that long-time simultaneous cooling and heating operations can be achieved, and an energy-efficient production line should be made. Can do.

  According to the production line system of the present invention, as described above, even if the cooling interlock mechanism is operated, the cooling target can be continuously cooled, so that the cooling target can be efficiently cooled. And an energy-efficient production line can be realized.

It is a figure which shows schematic structure of the production line system which concerns on embodiment. It is a flowchart which shows the operation | movement content of the heat pump cycle in a production line system. It is a flowchart which shows the processing content of a cooling interlock. It is a figure which shows the operation state (operation state) of each site | part which comprises the heat pump cycle in a production line system.

  DESCRIPTION OF EMBODIMENTS Hereinafter, an embodiment embodying a production line system of the present invention will be described in detail with reference to the drawings. In the following embodiment, the case where this invention is applied to the manufacturing line of a machined component is illustrated.

Therefore, the production line system according to the embodiment will be described with reference to FIG. FIG. 1 is a diagram illustrating a schematic configuration of a production line system according to an embodiment.
As shown in FIG. 1, the production line system 10 is provided for cooling the cutting fluid in the cutting process of machining part manufacture and heating the cleaning fluid in the subsequent cleaning process, and a plurality of cuttings for storing the cutting fluid. A liquid tank 11, a cleaning liquid tank 12 for storing the cleaning liquid, and a heat pump 20 for cooling the cutting liquid and heating the cleaning liquid are provided.

  The heat pump 20 is a three-mode heat pump, and a cooling heat exchanger 21 that cools cold water, which is a coolant for cooling the cutting fluid, by heat exchange, and a heating heat exchanger 22 that heats the cleaning liquid by heat exchange, And an air heat exchanger 23 that performs heat exchange between the heat pump refrigerant and air (atmosphere), and a compressor 24 that compresses the heat pump refrigerant. Each of these heat exchangers 21, 22, 23 and the compressor 24 is incorporated in a heat pump cycle. In the heat pump 20, by switching the operation of each of the heat exchangers 21, 22, and 23, simultaneous cooling / heating (cooling / heating) operation, single cooling operation, or single heating operation can be performed.

The cooling heat exchanger 21 is connected to a chilled water return pipe 30 that receives chilled water and a chilled water supply pipe 31 that discharges chilled water. A chilled water pump 32 that sends chilled water is attached to the chilled water supply pipe 31. When the cold water pump 32 is operated, the cold water is circulated through a cooling system constituted by the cold water return pipe 30, the cooling heat exchanger 21, the cold water supply pipe 31, and the heat exchanger 33.
In addition, a throw-in type heat exchanger 33 arranged for each cutting fluid tank 11 is connected to the cold water supply pipe 31, and a proportional valve 34 is installed in the cold water supply pipe 31 branched to each heat exchanger 33. Has been. The heat exchanger 33 cools the cutting fluid in the cutting fluid tank 11 by heat exchange by passing cold water that is introduced into the cutting fluid tank 11 and circulates through the cooling system. In FIG. 1, two cutting fluid tanks 11 are illustrated, but three or more cutting fluid tanks 11 may be installed and connected to the cooling heat exchanger 21.

  On the other hand, the heating heat exchanger 22 is connected to a cleaning liquid return pipe 40 that receives the cleaning liquid and a cleaning liquid supply pipe 41 that discharges the cleaning liquid. A cleaning liquid pump 42 for sending the cleaning liquid from the cleaning liquid tank 12 is attached to the other end of the cleaning liquid return pipe 40. The heating heat exchanger 22 heats the cleaning liquid introduced from the cleaning liquid return pipe 40 by heat exchange, leads it to the cleaning liquid supply pipe 41, and returns the heated cleaning liquid to the cleaning liquid tank 12.

  As described above, in the production line system 10, the cleaning liquid heat treatment process can be adjacent to or after the cutting liquid cooling treatment process, and the cooling treatment process and the heat treatment process can be made into a series. . Accordingly, the distance from the heat pump 20 to the cooling process or the heat treatment process is shortened, the cost is reduced by shortening the piping 30, 31, 40, 41, etc., and transmission loss is reduced, thereby further saving energy. Can be planned. In addition, the heating and cooling system can be completed for each series of processing lines in the factory, and the flexibility can be made extremely good. Further, since cooling and heating are always required at the same time during production in a series of processing lines, the heat pump 20 can use the heat taken or taken away from each other as a heat source in the heat pump 20. In addition, long-time simultaneous cooling and heating operations can be performed, and a production line with high energy efficiency can be obtained. Furthermore, since a three-mode heat pump is used as the heat pump 20, no matter how the cooling load or the heating load appears or changes, it is possible to flexibly cope with each process by switching the operation state. And energy efficiency can be extremely high.

  The heat pump 20 is connected to control means (not shown). The control means grasps the chilled water temperature at the outlet of the cooling heat exchanger 21 (the chilled water temperature in the chilled water supply pipe 31) and transmits the chilled water temperature sensor (not shown) and the cleaning liquid temperature in the cleaning liquid tank 12. A cleaning liquid temperature sensor (not shown) for transmission is connected. Each proportional valve 34 is connected to the control means so that the opening degree can be adjusted based on an opening degree command issued by the control means. Further, a cutting fluid tank temperature sensor (not shown) for grasping and transmitting the cutting fluid temperature in each cutting fluid tank 11 is connected to the control means.

  Here, the control means operates on the heating side of the heat pump 20 with the operating condition having a temperature range. That is, a lower limit value (for example, 50 ° C.) and an upper limit value (for example, 60 ° C.) of the cleaning liquid temperature are provided in the heating operation condition, and when the control means exceeds the upper limit value for the cleaning liquid temperature, the amount of heating by the heat pump 20 is reduced from the previous time. Is lowered, and if the lower limit is not reached, the amount of heating by the heat pump 20 is increased from immediately before to raise the cleaning liquid temperature. The temperature width W (difference between the upper limit value and the lower limit value) is preferably 2 to 10 ° C. The decrease in the cleaning liquid temperature occurs when the number of cleaning parts (cleaning amount) increases rapidly or when the cleaning liquid is replenished and injected.

The control means also operates on the cooling side of the heat pump 20 with the operating condition having a temperature range. That is, a cooling lower limit value (for example, 20 ° C.) and a cooling upper limit value (for example, 30 ° C.) are provided in the cooling operation condition, and when the control means falls below the cooling lower limit value for the cutting fluid temperature, the cooling amount by the heat pump 20 is immediately before Further, the temperature of the cutting fluid is allowed to rise, and when the cooling upper limit value is exceeded, the cooling amount by the heat pump 20 is increased from immediately before to lower the cutting fluid temperature. The temperature width (difference between the cooling upper limit value and the cooling lower limit value) is preferably 2 to 10 ° C.
Further, the control means adjusts the opening degree of the corresponding proportional valve 34 according to the cutting fluid temperature in the individual cutting fluid tank 11 obtained from the cutting fluid tank temperature sensor or the separately obtained cold water temperature.

  Further, on the cooling side of the heat pump 20, the control means provides a cooling lower limit value (7 ° C. in the present embodiment) of the chilled water temperature in order to prevent the cooling heat exchanger 21 from freezing, and the chilled water temperature is lower than the cooling lower limit value. The cooling interlock mechanism is activated when the following occurs (interlock ON). That is, in the heat pump 20, heat exchange by the cooling heat exchanger 21 is stopped, and cooling of the cold water (cooling operation of the heat pump) is stopped. However, when there is a cooling request for the cutting fluid, the control means operates the cold water pump 32 to circulate the cold water in the cooling system. Details of this will be described later. The cooling water temperature decreases when the number of cutting fluid tanks 11 requiring cooling is smaller than the number of installed cutting fluid tanks 11 or when the heat exchanger 33 becomes dirty and the heat exchange capability decreases. Occur.

  Next, the operation of the production line system 10 described above will be described with reference to FIGS. FIG. 2 is a flowchart showing the operation content of the heat pump cycle in the production line system. FIG. 3 is a flowchart showing the processing contents of the cooling interlock. FIG. 4 is a diagram showing the operating state (operating state) of each part constituting the heat pump cycle in the production line system. Note that the processes shown in FIGS. 2 and 3 are repeatedly performed in a cycle of several msec.

  As shown in FIG. 2, in the production line system 10, it is first determined whether or not there is a heating request for the cleaning liquid (ON / OFF) (step S10). At this time, if the heating request is ON (S10: ON), the heat exchanger 22 for heating is turned ON (Step S11), and the cleaning liquid pump 42 is turned ON (Step S12).

  Next, it is determined whether or not there is a cooling fluid cooling request (ON / OFF) (step S13). At this time, if the cooling request is ON (S13: ON), ON / OFF of the cooling interlock is determined (step S14).

  Here, the ON / OFF determination process of the cooling interlock will be briefly described. In this determination processing, as shown in FIG. 3, it is determined whether or not the chilled water temperature Tcout in the vicinity of the outlet of the cooling heat exchanger 21 is 7 ° C. or less (step S80). At this time, when the cold water temperature Tcout is 7 ° C. or less (S80: Yes), the cooling interlock is turned on (step S81). Thereby, even if it is a case where there exists a cooling request | requirement, cooling of the cold water by the heat pump 20 (heat exchanger 21 for cooling) is stopped.

  On the other hand, when the chilled water temperature Tcout is higher than 7 ° C. (S80: No), the current ON / OFF state of the cooling interlock is determined. At this time, if the cooling interlock is ON (S82: ON), it is determined whether or not the chilled water temperature Tcout is 15 ° C. or higher (step S83). When the cold water temperature Tcout is 15 ° C. or higher (S83: Yes), the cooling interlock is turned off (step S84).

If the cooling interlock is OFF in step S82, or if the chilled water temperature Tcout is lower than 15 ° C. in step S83, the process is temporarily terminated.
Thereafter, by repeatedly executing the processes of steps S80 to S84 described above, in the present embodiment, the cooling interlock is turned on when the chilled water temperature Tcout is 7 ° C. or less, and the cooling interlock is turned on. When the cold water temperature Tcout becomes 15 ° C. or higher, the cooling interlock is turned off.

  Returning to FIG. 2, when the cooling interlock is ON in step S14 (S14: ON), the cooling heat exchanger 21 is turned OFF (step S15), but the cold water pump 32 is turned ON (step S15). Step S16). Next, the air heat exchanger 23 is turned on (step S17), and the compressor 24 is turned on (step S18).

  Thereby, even if the cooling interlock is ON, the cold water circulates through the cooling system by the cold water pump 32. At this time, since the temperature of the cold water circulating through the cooling system is 7 ° C. or less, the cutting fluid can be cooled by the cold water via the heat exchanger 33. Therefore, even if the cooling interlock is turned on, the cutting fluid can be continuously cooled. Moreover, since the temperature rise of the cold water can be accelerated by circulating the cold water to the cooling system, the time until the cooling interlock is turned off can be shortened. Thus, in the production line system 10, the cutting fluid can be efficiently cooled, and a production line system with high energy efficiency can be realized.

  Further, in the production line system 10, the cooling target is a cutting fluid, and the cutting fluid is contaminated by machining, so that the efficiency of heat exchange in the heat exchanger 33 decreases and the cold water is generated. The probability of overcooling is high, and the frequency with which the interlock is turned on is high. Furthermore, when the number of cutting fluid tanks 11 is increased and the number of tanks requiring cooling decreases (for example, when only one of the installed units issues a cooling request), the heat exchanger 33 performs heat exchange. Since the amount of heat (the amount of heat received from the cutting fluid) is reduced, cold water tends to be overcooled. In such a production line system 10 according to the present embodiment, the number of times the cooling interlock is turned on tends to increase. However, since the cutting fluid can be efficiently cooled, energy saving can be achieved. .

  If the cooling request is OFF in step S13 (S13: OFF), the cooling heat exchanger 21 is turned OFF (step S20), and the chilled water pump 32 is also turned OFF (step S21). Next, the air heat exchanger 23 is turned on (step S22), and the compressor 24 is turned on (step S23). Thereby, in the heat pump 20, a heating single operation is implemented. When the cooling request is OFF, the cooling heat exchanger 21 is turned OFF, and the ON / OFF determination of the cooling interlock is not performed.

  In Step S14, when the cooling interlock is OFF (S14: OFF), the cooling heat exchanger 21 is turned ON (Step S30), and the chilled water pump 32 is turned ON (Step S31). Next, the air heat exchanger 23 is turned off (step S32), and the compressor 24 is turned on (step S33). Thereby, in the heat pump 20, the cooling and heating simultaneous operation is performed.

  On the other hand, when the heating request is OFF (S10: OFF), the cleaning liquid pump 42 is turned OFF (Step S40), and the heating heat exchanger 22 is turned OFF (Step S41). Next, it is determined whether or not there is a cooling request (ON / OFF) (step S42). At this time, when the cooling request is ON (S42: ON), ON / OFF of the cooling interlock is determined (step S43). At this time, when the cooling interlock is ON (S43: ON), the cooling heat exchanger 21 is turned off (step S44), but the chilled water pump 32 is turned on (step S45). Next, the air heat exchanger 23 is turned off (step S46), and the compressor 24 is turned off (step S47).

  Thereby, even if the cooling interlock is ON, since the cold water pump 32 operates, cold water of 7 ° C. or less circulates in the cooling system, so that the cutting fluid can be cooled by the cold water via the heat exchanger 33. . Accordingly, the cooling of the cutting fluid can be continuously performed, and the time until the cooling interlock is turned off by increasing the temperature rise of the cold water can be shortened.

  If the cooling request is OFF in step S42 (S42: OFF), the cooling heat exchanger 21 is turned OFF (step S50), and the chilled water pump 32 is also turned OFF (step S51). Next, the air heat exchanger 23 is turned off (step S52), and the compressor 24 is turned off (step S53). As a result, the heat pump 20 is stopped. When the cooling request is OFF, the cooling heat exchanger 21 is turned OFF, and the ON / OFF determination of the cooling interlock is not performed.

  In step S43, when the cooling interlock is OFF (S43: OFF), the cooling heat exchanger 21 is turned ON (step S60), and the chilled water pump 32 is turned ON (step S61). Next, the air heat exchanger 23 is turned on (step S62), and the compressor 24 is turned on (step S63). Thereby, in the heat pump 20, a cooling single operation is implemented.

  The operation patterns described above can be classified into patterns A to H shown in FIG. 4 depending on the combination of the presence / absence of a heating request, the presence / absence of a cooling request, and the on / off state of a cooling interlock. Hereinafter, the relationship with the above processing will be briefly described for each pattern.

[Pattern A]
In pattern A, both the heating request and the cooling request are ON, and the cooling interlock is OFF. Accordingly, the processes of steps S10 to S14 and S30 to S33 are sequentially performed. As a result, the compressor 24 is turned on, the air heat exchanger 23 is turned off, the heating heat exchanger 22 is turned on, the cooling heat exchanger 21 is turned on, the cleaning liquid pump 42 is turned on, the cold water pump 32 is turned on, and the heat pump 20 Then, cooling and heating simultaneous operation is carried out.

[Pattern B]
In pattern B, the heating request is ON, the cooling request is OFF, and the cooling interlock is OFF. Accordingly, the processes of steps S10 to S13 and S20 to S23 are sequentially performed. As a result, the compressor 24 is turned on, the air heat exchanger 23 is turned on, the heating heat exchanger 22 is turned on, the cooling heat exchanger 21 is turned off, the cleaning liquid pump 42 is turned on, the cold water pump 32 is turned off, and the heat pump 20 Then, a single heating operation is performed.

[Pattern C]
In pattern C, the heating request is OFF, the cooling request is ON, and the cooling interlock is OFF. Accordingly, steps S10, S40 to S43, and S60 to S63 are sequentially performed. As a result, the compressor 24 is turned on, the air heat exchanger 23 is turned on, the heating heat exchanger 22 is turned off, the cooling heat exchanger 21 is turned on, the cleaning liquid pump 42 is turned off, the cold water pump 32 is turned on, and the heat pump 20 Then, the cooling single operation is carried out.

[Pattern D]
In pattern D, both the heating request and the cooling request are OFF, and the cooling interlock is OFF. Accordingly, steps S10, S40 to S42, and S50 to S53 are sequentially performed. As a result, the compressor 24 is turned off, the air heat exchanger 23 is turned off, the heating heat exchanger 22 is turned off, the cooling heat exchanger 21 is turned off, the cleaning liquid pump 42 is turned off, the cold water pump 32 is turned off, and the heat pump 20 Is stopped.

[Pattern E]
In pattern E, both the heating request and the cooling request are ON, and the cooling interlock is ON. Accordingly, the processes of steps S10 to S18 are sequentially performed. As a result, the compressor 24 is turned on, the air heat exchanger 23 is turned on, the heating heat exchanger 22 is turned on, the cooling heat exchanger 21 is turned off, the cleaning liquid pump 42 is turned on, the cold water pump 32 is turned on, and the heat pump 20 Then, a single heating operation is performed. That is, even if the cooling request is ON, since the cooling interlock is ON, the coolant is not cooled by the heat pump 20 (indirect cooling via the cold water), but the cold water is supplied to the cooling system by the cold water pump 32. Circulation is performed to cool the cutting fluid. Thereby, even if the cooling interlock is ON, the cutting fluid can be continuously cooled.

[Pattern F]
In pattern F, the heating request is ON, the cooling request is OFF, and the cooling interlock is ON. Accordingly, the processes of steps S10 to S13 and S20 to S23 are sequentially performed. As a result, the compressor 24 is turned on, the air heat exchanger 23 is turned on, the heating heat exchanger 22 is turned on, the cooling heat exchanger 21 is turned off, the cleaning liquid pump 42 is turned on, the cold water pump 32 is turned off, and the heat pump 20 Then, a single heating operation is performed.

[Pattern G]
In pattern G, the heating request is OFF, the cooling request is ON, and the cooling interlock is ON. Accordingly, the processes of steps S10 and S40 to S47 are sequentially performed. As a result, the compressor 24 is turned off, the air heat exchanger 23 is turned off, the heating heat exchanger 22 is turned off, the cooling heat exchanger 21 is turned off, the cleaning liquid pump 42 is turned off, the cold water pump 32 is turned on, and the heat pump 20 Is stopped. That is, even if the cooling request is ON, since the cooling interlock is ON, the coolant is not cooled by the heat pump 20 (indirect cooling via the cold water), but the cold water is supplied to the cooling system by the cold water pump 32. Circulation is performed to cool the cutting fluid. Thereby, even if the cooling interlock is ON, the cutting fluid can be continuously cooled.

[Pattern H]
In the pattern H, both the heating request and the cooling request are OFF, and the cooling interlock is ON. Accordingly, steps S10, S40 to S42, and S50 to S53 are sequentially performed. As a result, the compressor 24 is turned off, the air heat exchanger 23 is turned off, the heating heat exchanger 22 is turned off, the cooling heat exchanger 21 is turned off, the cleaning liquid pump 42 is turned off, the cold water pump 32 is turned off, and the heat pump 20 Is stopped.

  As described above in detail, according to the production line system 10 according to the present embodiment, when the chilled water temperature is equal to or lower than the cooling lower limit (7 ° C. in the present embodiment), the cooling interlock is turned on. Then, cooling of the cold water by the heat pump 20 is stopped. At this time, when there is a cooling request for the cutting fluid, the cold water pump 32 is turned on to circulate the cold water to the cooling system. Thereby, cutting fluid can be cooled with low-temperature cold water. Therefore, even if the cooling interlock is ON, the cutting fluid can be continuously cooled. Moreover, since the temperature rise of cold water can be accelerated, the time until the temperature rise of cold water is accelerated and the cooling interlock is turned off can be shortened. By these things, cooling of a cutting fluid can be performed efficiently and the energy efficiency in the production line system 10 can be improved.

  It should be noted that the above-described embodiment is merely an example and does not limit the present invention in any way, and various improvements and modifications can be made without departing from the scope of the invention. For example, in the above-described embodiment, a three-mode type heat pump 20 is illustrated, but the heat pump 20 is not limited to this, and may be any one that performs at least a cooling operation.

  Moreover, although the case where this invention was applied to the manufacturing line of machined components was illustrated in the above-mentioned embodiment, it can be applied also to other production lines (for example, a painting line provided with a cooling furnace, etc.).

DESCRIPTION OF SYMBOLS 10 Production line system 11 Cutting fluid tank 12 Cleaning fluid tank 20 Heat pump 21 Cooling heat exchanger 22 Heating heat exchanger 23 Air heat exchanger 24 Compressor 30 Chilled water return piping 31 Chilled water supply piping 32 Chilled water pump 33 Heat exchanger 34 Proportional Valve 40 Cleaning liquid return pipe 41 Cleaning liquid supply pipe 42 Cleaning liquid pump

Claims (6)

In a production line system having at least a cooling process step for cooling an object to be cooled by a heat pump cycle,
In the cooling treatment step, the cooling object is cooled by a refrigerant circulating in a cooling system, the refrigerant is cooled by the heat pump cycle,
When the refrigerant falls below a predetermined lower limit value, the cooling of the refrigerant by the heat pump cycle is stopped, and when there is a cooling request for the cooling target, the refrigerant is circulated through the cooling system. Production line system. In the production line system according to claim 1,
In the cooling treatment step, the refrigerant cooled by heat exchange with the heat pump refrigerant is circulated to the cooling system with a refrigerant pump, the cooling object is cooled with the refrigerant circulating in the cooling system,
When the refrigerant falls below a predetermined lower limit value, the cooling of the refrigerant by the heat pump refrigerant is stopped, and when there is a cooling request for the cooling target, the refrigerant pump is operated to bring the refrigerant into the cooling system. A production line system characterized by circulation. In the production line system according to claim 2,
The cooling object is a coolant stored in a coolant tank for supplying to a machining machine that processes a workpiece,
A production line system comprising a plurality of the coolant tanks. In the production line system according to claim 3,
Having a heat treatment step of heating the object to be heated;
The heat treatment step and the cooling treatment step are performed with one heat pump,
The production line system according to claim 3, wherein the heat pump is a three-mode heat pump capable of simultaneous cooling / heating operation, single cooling operation, or single heating operation. In the production line system according to claim 4,
When the refrigerant is below a predetermined lower limit,
When there is a heating request for the heating target, the heat pump performs a heating single operation regardless of the cooling request for the cooling target,
When there is a cooling request for the cooling target, the production line system is characterized in that the refrigerant pump is operated to circulate the refrigerant through the cooling system. In the production line system according to claim 4 or 5,
The production line system according to claim 1, wherein the heating target is a cleaning liquid for cleaning the workpiece before or after the workpiece is processed.

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