JP6127099B2 - Temperature control system - Google Patents

Description

  The present invention relates to a temperature adjustment system for adjusting the temperature of an object, and more particularly to a temperature adjustment system for adjusting the temperature of an object such as a mold used for injection molding.

  Conventionally, a configuration is known in which an injection mold is cooled with a cooling medium such as water and the cooling medium is cooled with a chiller.

  For example, a storage unit that stores a low-temperature medium that cools an injection mold and a plurality of cooling units that cool the low-temperature medium in the storage unit, and the cooling capacity of the plurality of cooling units is higher than the cooling load in the mold. There has been proposed a cooling device that reduces the number of operating cooling units when it is excessive (see, for example, Patent Document 1 below).

JP 2014-786 A

  However, in the cooling device as described in Patent Document 1, further energy saving is studied.

  Therefore, an object of the present invention is to provide a temperature control system capable of further saving energy.

[1] The present invention provides a storage unit that stores a first cooling medium, a first temperature detection unit that measures a first temperature that is a temperature of the first cooling medium in the storage unit, and the first unit in the storage unit. 1st supply line which supplies 1 cooling medium to a target object, The return line which returns the 1st cooling medium which cooled the target object to the storage part, The 1st cooling medium in the storage part, or the return A cooling unit and a heat exchanger for cooling the first cooling medium in the line; a second supply line for supplying the second cooling medium for cooling the first cooling medium to the heat exchanger; 2 comprising: a second temperature detecting means for measuring a second temperature which is the temperature of the second cooling medium in the supply line; and a control unit for controlling the operation of the cooling unit, wherein the control unit includes the second temperature. Is lower than the first temperature and the first temperature If the difference between the degrees and the second temperature exceeds a predetermined value, it stops the operation of the cooling unit, a temperature regulating system.

  According to such a configuration, the temperature (second temperature) of the second cooling medium for cooling the first cooling medium in the reservoir or the first cooling medium in the return line is the temperature of the first cooling medium. When the temperature is lower than (first temperature) and the difference between the first temperature and the second temperature exceeds a predetermined value, the operation of the cooling unit is stopped.

  Thereby, when the temperature of the second cooling medium (second temperature) is sufficiently lower than the temperature of the first cooling medium (first temperature), the first cooling medium in the storage unit only with the heat exchanger, Alternatively, the first cooling medium in the return line can be cooled.

As a result, energy saving can be further achieved as compared with the case where the first cooling medium is cooled by the cooling unit.
[2] In the present invention, the cooling unit and the heat exchanger cool the first cooling medium in the return line, and the heat exchanger includes a high-temperature side passage through which the first cooling medium flows. A low-temperature side passage through which the second cooling medium flows, the return line including a cooling line connected to the high-temperature side passage, a bypass line bypassing the heat exchanger, and the cooling line Switching means movable between a first position that opens and closes the bypass line; and a second position that opens the bypass line and closes the cooling line; When the second temperature is lower than the first temperature and the difference between the first temperature and the second temperature is equal to or less than a predetermined value, the cooling unit is operated and the switching means is moved to the first position. In the above [1] Including the temperature control system of.

  According to such a configuration, the temperature of the second cooling medium (second temperature) is lower than the temperature of the first cooling medium (first temperature), and the difference between the first temperature and the second temperature is a predetermined value. In the following cases, the switching means is positioned at the first position and the first cooling medium is introduced into the cooling line.

  Thereby, the 1st cooling medium in a return line can be cooled using a cooling unit and a heat exchanger together.

As a result, the first cooling medium in the return line can be cooled in a short time.
[3] The present invention further includes a third supply line that supplies the first cooling medium in the reservoir to the first supply line, and the cooling unit and the heat exchanger are provided in the third supply line. By cooling the first cooling medium, the first cooling medium in the storage unit is cooled, and the heat exchanger has a high-temperature channel through which the first cooling medium flows, and the second cooling medium flows. A low-temperature side flow path, wherein the third supply line opens a cooling line connected to the high-temperature side flow path, a bypass line that bypasses the heat exchanger, and opens the cooling line, the bypass line And a switching means that can move between a first position that closes the cooling line and a second position that opens the bypass line and closes the cooling line, and the control unit is configured such that the second temperature is the first temperature. Lower than the temperature, and When the difference between the temperature and the second temperature is less than or equal to a predetermined value, the temperature control system according to [1] is included, wherein the cooling unit is operated and the switching unit is positioned at the first position. .

  According to such a configuration, the temperature of the second cooling medium (second temperature) is lower than the temperature of the first cooling medium (first temperature), and the difference between the first temperature and the second temperature is a predetermined value. In the following cases, the switching means is positioned at the first position and the first cooling medium is introduced into the cooling line.

  Thereby, the 1st cooling medium in the 3rd supply line can be cooled together using a cooling unit and a heat exchanger.

As a result, the first cooling medium in the third supply line can be cooled in a short time.
[4] In the present invention, the control unit operates the cooling unit and positions the switching unit at the second position when the second temperature is equal to or higher than the first temperature. ] Or the temperature control system according to [3].

  According to such a configuration, when the temperature of the second cooling medium (second temperature) is equal to or higher than the temperature of the first cooling medium (first temperature), the switching unit is positioned at the second position to perform the first cooling. Introduce media into the bypass line.

  Thereby, a 1st cooling medium can be made to flow around a heat exchanger.

As a result, when the temperature of the second cooling medium supplied to the heat exchanger is high, the first cooling medium can be cooled by the cooling unit without using the heat exchanger.
[5] In the present invention, the control unit moves the switching unit between the first position and the second position based on PID control in a state where the operation of the cooling unit is stopped. The temperature control system according to any one of [2] to [4] above is included.

  According to such a configuration, the switching means is moved between the first position and the second position based on the PID control in a state where the operation of the cooling unit is stopped, and is introduced into the cooling line. 1 Adjust the amount of cooling medium.

Thereby, when the operation of the cooling unit is stopped, the first cooling medium can be efficiently cooled using the heat exchanger.
[6] In the present invention, the heat exchanger is a heat exchanger for exchanging heat between liquids, and the second cooling medium is water supplied from the outside. [5] The temperature control system according to any one of [5] is included.

  According to such a configuration, when the temperature of the water supplied from the outside is sufficiently lower than the temperature of the first cooling medium, the first cooling medium can be cooled using the water.

  As a result, further energy saving can be achieved.

  The present invention can achieve further energy saving as compared with the case where the first cooling medium is cooled by the cooling unit.

FIG. 1 is a schematic configuration diagram showing a cooling system as a first embodiment of a temperature control system of the present invention. FIG. 2 is a control block diagram of the cooling system shown in FIG. FIG. 3 is a flowchart of cold water temperature control of the cooling system shown in FIG. FIG. 4 is a schematic configuration diagram showing a second embodiment of the temperature control system of the present invention. FIG. 5 is a flowchart showing cold water temperature control of a modification of the temperature control system of the present invention.

<First Embodiment>
FIG. 1 is a schematic configuration diagram showing a cooling system as a first embodiment of a temperature control system of the present invention.

  A cooling system 1 as an example of a temperature control system is a cooling system that cools a molding die M as an example of an object, as shown in FIG. The cooling system 1 includes a circulation unit 2, a cooling unit 3, a cooling water line 4 as an example of a second supply line, and a control unit 31 (see FIG. 2).

  The circulation unit 2 includes a cold water tank 5 as an example of a storage unit, a cold water supply line 6 as an example of a first supply line, a cold water return line 7 as an example of a return line, and a heat exchanger 8.

  The cold water tank 5 is a tank that stores water as an example of the first cooling medium. The cold water tank 5 includes a water supply pipe 5A, a float switch 5B, and a cold water temperature sensor 32 as an example of a first temperature detection unit.

  The water supply pipe 5 </ b> A is a pipe for supplying water to the cold water tank 5 from the outside. The downstream end of the water supply pipe 5 </ b> A (the downstream end in the water flow direction; the same applies in the following description) is connected to the upper end of the cold water tank 5. The upstream end of the water supply pipe 5A (upstream end in the direction of water flow; the same applies in the following description) is connected to a water source such as industrial water (not shown).

  The float switch 5B is connected to the downstream end of the water supply pipe 5A. The float switch 5B is turned on when the water level in the cold water tank 5 falls below a predetermined water level. Thereby, the cold water tank 5 is supplied with water from the water supply pipe 5A. The float switch 5B is turned off when the water level of the cold water tank 5 becomes a predetermined water level or higher. Thereby, the water supply from the water supply pipe 5A to the cold water tank 5 is stopped.

The cold water temperature sensor 32 is arranged on the wall of the cold water tank 5 so that the tip of the probe faces the cold water tank 5. The cold water temperature sensor 32 measures the temperature of the water in the cold water tank 5 (the cold water temperature T ₁ as an example of the first temperature). The cold water temperature sensor 32 is electrically connected to a cold water temperature indicator 35 (see FIG. 2) described later.

  The cold water supply line 6 is a pipe for supplying water in the cold water tank 5 to the molding die M. The upstream end of the cold water supply line 6 is connected to the cold water tank 5. The downstream end of the cold water supply line 6 is connected to the inlet M1 of the molding die M. The cold water supply line 6 includes a pump 9.

  The pump 9 is interposed in the middle of the cold water supply line 6. The pump 9 sends the water in the cold water tank 5 to the molding die M.

  The cold water return line 7 is a pipe for returning the water that has cooled the molding die M to the cold water tank 5 via the cooling unit 3. The upstream end of the cold water return line 7 is connected to the outlet M2 of the molding die M. The downstream end of the cold water return line 7 is connected to the cold water tank 5. The cold water return line 7 includes an upstream line 10 disposed on the upstream side of the cooling unit 3 and a downstream line 11 disposed on the downstream side of the cooling unit 3.

  The upstream line 10 is a pipe for sending water that has cooled the molding die M to an evaporator 21 (described later) of the cooling unit 3. The upstream end of the upstream line 10 is connected to the outlet M2 of the molding die M. Further, the downstream end portion of the upstream line 10 is connected to the inlet 21 </ b> A on the cooled side of the evaporator 21 of the cooling unit 3.

  The downstream line 11 is a pipe for sending water that has passed through the evaporator 21 of the cooling unit 3 to the cold water tank 5. The upstream end of the downstream line 11 is connected to the outlet 21 </ b> B on the cooled side of the evaporator 21 of the cooling unit 3. The downstream end of the downstream line 11 is connected to the cold water tank 5. The downstream line 11 includes a cooling line 12, a bypass line 13, and a three-way valve 14 as an example of a switching unit. The downstream line 11 is branched into a cooling line 12 and a bypass line 13 on the way. The cooling line 12 and the bypass line 13 merge via a three-way valve 14.

  The cooling line 12 is a pipe for introducing water in the downstream line 11 into the heat exchanger 8. The cooling line 12 includes an upstream portion 12 </ b> A disposed on the upstream side of the heat exchanger 8 and a downstream portion 12 </ b> B disposed on the downstream side of the heat exchanger 8.

  The upstream end portion of the upstream portion 12A is connected to a branch portion between the cooling line 12 and the bypass line 13. The downstream end of the upstream portion 12A is connected to an inlet 8A of a cooled side flow path 8E (described later) of the heat exchanger 8.

  The upstream end of the downstream portion 12B is connected to the outlet 8B of the cooled channel 8E of the heat exchanger 8. The downstream end of the downstream portion 12B is connected to the three-way valve 14.

  The bypass line 13 is a pipe for bypassing the heat exchanger 8 and supplying the water in the downstream line 11 to the cold water tank 5. An upstream end portion of the bypass line 13 is connected to a branch portion between the cooling line 12 and the bypass line 13. The downstream end of the bypass line 13 is connected to the three-way valve 14.

  The three-way valve 14 is disposed at the junction of the cooling line 12 and the bypass line 13. The three-way valve 14 is electrically connected to a cold water temperature indicator 35 (see FIG. 2) described later. The three-way valve 14 opens the cooling line 12 and closes the bypass line 13 as a cooling position as an example of a first position, and opens the bypass line 13 and closes the cooling line 12 as a bypass as an example of a second position. It can move between positions.

  The heat exchanger 8 is interposed in the middle of the cooling line 12. The heat exchanger 8 is, for example, a counter flow type heat exchanger. Specifically, the heat exchanger 8 is an example of a cooled side channel 8E as an example of a high temperature side channel through which water in the downstream line 11 circulates, and an example of a low temperature side channel through which cooling water from the outside circulates. Cooling side flow path 8F. The heat exchanger 8 is configured such that the water flowing in the cooled side flow path 8E and the water flowing in the cooling side flow path 8F flow in opposite directions, and pass through the cooled side flow path 8E. Heat is exchanged between the flowing water and the water flowing in the cooling side flow path 8F. The cooling capacity of the heat exchanger 8 is, for example, 30 kW or more, for example, 50 kW or less. The cooling capacity of the heat exchanger 8 is, for example, 100% or more, for example, 105% or less, when the cooling capacity of the cooling unit 3 is 100%.

  The cooling unit 3 is interposed in the middle of the cold water return line 7 on the upstream side of the heat exchanger 8. The cooling unit 3 is, for example, a known chiller (chiller), and includes a circulation line 23, an evaporator 21, a condenser 22, and a bypass line 24.

  The circulation line 23 is a pipe that circulates, for example, a refrigerant such as hydrofluorocarbon between the cooling side of the evaporator 21 and the cooled side of the condenser 22. The circulation line 23 includes a compressor 25 and an expansion valve 26.

  The compressor 25 is disposed downstream of the evaporator 21 and upstream of the condenser 22 in the refrigerant flow direction. The compressor 25 compresses the refrigerant (gas) vaporized in the evaporator 21 and sends the compressed refrigerant (gas) to the condenser 22.

  The expansion valve 26 is disposed downstream of the condenser 22 and upstream of the evaporator 21 in the refrigerant flow direction. The expansion valve 26 depressurizes the refrigerant (liquid) liquefied in the condenser 22.

  The evaporator 21 cools the water in the cold water return line 7 by vaporizing the refrigerant (liquid) decompressed by the expansion valve 26.

  The condenser 22 condenses the refrigerant (gas) compressed by the compressor 25 by cooling it with cooling water in the cooling water line 4 described later.

  The bypass line 24 is a pipe for circulating the refrigerant that has passed through the evaporator 21, bypassing the condenser 22.

  The cooling water line 4 is a pipe that introduces cooling water as an example of the second cooling medium to the cooling side of the heat exchanger 8 and the cooling side of the condenser 22. The cooling water line 4 includes a supply unit 4a, a connection unit 4b, and a discharge unit 4c.

  The upstream end of the supply unit 4a is connected to a water source such as industrial water (not shown). The downstream end of the supply unit 4a is connected to the inlet 8C of the cooling side flow path 8F of the heat exchanger 8. Supply part 4a is provided with cooling water temperature sensor 33 as an example of the 2nd temperature detection means.

The coolant temperature sensor 33 is disposed in the vicinity of the inlet 8C of the heat exchanger 8 in the middle of the supply unit 4a. The cooling water temperature sensor 33 measures the temperature of the cooling water in the supply unit 4a (cooling water temperature T ₂ as an example of the second temperature). The coolant temperature sensor 33 is electrically connected to a coolant temperature indicator 34 (see FIG. 2) described later.

  The upstream end portion of the connection portion 4b is connected to the outlet 8D of the cooling side flow path 8F of the heat exchanger 8. The downstream end of the connection portion 4 b is connected to the cooling-side inlet 22 </ b> A of the condenser 22.

  The upstream end of the discharge part 4 c is connected to the outlet 22 </ b> B on the cooling side of the condenser 22. The downstream end of the discharge part 4c is connected to, for example, a drainage facility (not shown).

  FIG. 2 is a block diagram of a control unit of the cooling system shown in FIG.

  The control unit 31 controls operations of the compressor 25 of the cooling unit 3, the pump 9 of the circulation unit 2, and the three-way valve 14. As shown in FIG. 2, a chilled water temperature indicator 35, a chilled water temperature indicator 34, a control board 36, and a sequence circuit 37 are provided.

The cold water temperature indicator 35 is disposed in the vicinity of the cold water tank 5. The cold water temperature indicator 35 is electrically connected to the cold water temperature sensor 32, the control board 36 and the three-way valve 14. The chilled water temperature indicator 35 displays the chilled water temperature T ₁ measured by the chilled water temperature sensor 32 and transmits the temperature to the control board 36. In addition, an arbitrary set value (cold water temperature set value T ₀ ) can be input to the cold water temperature indicator 35 by an operator's operation. The cold water temperature indicator 35 also transmits the input set value to the control board 36.

The cooling water temperature indicator 34 is disposed in the vicinity of the supply unit 4 a of the cooling water line 4. The cooling water temperature indicator 34 is electrically connected to the cooling water temperature sensor 33 and the control board 36. The cooling water temperature indicator 34 displays the cooling water temperature T ₂ measured by the cooling water temperature sensor 33 and transmits the temperature to the control board 36.

The control board 36 is configured as a circuit board including, for example, a memory such as a RAM and a ROM, a CPU, and the like. For example, the chilled water temperature T ₁ , the chilled water temperature set value T ₀ , and the chilled water temperature T ₂ are temporarily stored in the RAM. The ROM, the temperature control program for controlling the cold water temperature T ₁ is stored. The CPU executes a temperature control program.

  The sequence circuit 37 is electrically connected to the cold water temperature indicator 35 and the control board 36. The sequence circuit 37 includes a relay switch and the like, and drives the three-way valve 14 via the cold water temperature indicator 35.

  FIG. 3 is a flowchart of cold water temperature control of the cooling system shown in FIG.

Next, the cold water temperature control of the cooling system 1 will be described with reference to FIGS. In the following description, the cold water temperature set value T ₀ is set to 5 ° C., for example. The cooling system 1 adjusts the chilled water temperature T ₁ in the chilled water tank 5 to the chilled water temperature set value T ₀ .

  When the cooling system 1 is operated, the temperature control program stored in the ROM of the control board 36 is executed by the CPU of the control board 36.

Then, the cooling water temperature T ₂ is lower than the cold water temperatures T _1, and, if the difference between the chilled water temperatures T ₁ and the cooling water temperature T ₂ is less than a predetermined set value (stop setting value Delta] t) (S1: NO , S2: NO), the three-way valve 14 is positioned at the cooling position when the sequence circuit 37 determines that the compressor 25 of the cooling unit 3 is in operation (S3: YES) (S4).

  The stop set value Δt is set to, for example, 5 ° C. or higher, preferably 10 ° C. or higher, for example, 15 ° C. or lower.

More specifically, when the stop set value Δt is set to 10 ° C., the cold water temperature T ₁ is, for example, 10 ° C., and the cooling water temperature T ₂ is, for example, 3 ° C., the cooling unit 3 The three-way valve 14 is positioned at the cooling position while the compressor 25 is operating.

  When the cooling system 1 is operated, the compressor 25 of the cooling unit 3 and the pump 9 of the circulation unit 2 are operated. In this description, it is assumed that cooling water from the outside is always flowing in the cooling water line 4. The cooling water from the outside is supplied to the cooling side of the heat exchanger 8 via the supply part 4a, and then supplied to the cooling side of the condenser 22 of the cooling unit 3 via the connection part 4b.

  When the compressor 25 of the cooling unit 3 is operated, the refrigerant of the cooling unit 3 circulates in the circulation line 23.

  When the pump 9 of the circulation unit 2 is operated, the water in the cold water tank 5 is supplied to the inlet M1 of the molding die M via the cold water supply line 6 by the pump 9. Thereby, the molding die M is cooled by the water supplied to the inlet M1. Although the temperature of the water supplied to the molding die M depends on the temperature of the molding die M, it rises to 13 ° C., for example. Thereafter, the water that has cooled the molding die M is supplied to the inlet 21 </ b> A on the cooled side of the evaporator 21 through the outlet M <b> 2 of the molding die M and the upstream line 10 of the cold water return line 7.

  Then, the water supplied to the inlet 21A on the cooled side of the evaporator 21 is cooled by heat exchange with the refrigerant of the cooling unit 3, and the cold water return line 7 is passed through the outlet 21B on the cooled side of the evaporator 21. To the downstream line 11. The temperature of the water discharged to the downstream line 11 of the cold water return line 7 is, for example, 10 ° C.

  The water discharged to the downstream line 11 of the cold water return line 7 is supplied to the cooled side of the heat exchanger 8 via the upstream portion 12a of the cooling line 12 because the three-way valve 14 is located at the cooling position. It is supplied to the inlet 8A.

  Then, the water supplied to the inlet 8A on the cooled side of the heat exchanger 8 is cooled by heat exchange with the cooling water in the heat exchanger 8, and through the outlet 8B on the cooled side of the heat exchanger 8, It is discharged to the downstream portion 12b of the cooling line 12. The temperature of the water discharged to the downstream portion 12b of the cooling line 12 is 7 ° C., for example. The water discharged to the downstream portion 12 b of the cooling line 12 is returned to the cold water tank 5 through the downstream line 11 of the cold water return line 7.

Incidentally, when the cooling water temperature _{T 2} is higher than the chilled water temperature _{T 1 (S1: NO, S2} : YES), the three-way valve 14, the sequence circuit 37, is positioned in the bypass position (S5).

Specifically, when the cold water temperature T ₁ is, for example, 10 ° C. and the cooling water temperature T ₂ is, for example, 15 ° C., the three-way valve is operated while the compressor 25 of the cooling unit 3 is operating. 14 is located in the bypass position.

  In this case, the water discharged to the downstream line 11 of the cold water return line 7 bypasses the heat exchanger 8 via the bypass line 13 and the downstream line 11 of the cold water return line 7 and enters the cold water tank 5. Returned.

When the cooling water temperature T ₂ is lower than the cold water temperature T ₁ by exceeding the stop set value Δt, that is, the cooling water temperature T ₂ is lower than the cold water temperature T ₁ , and the cold water temperature T ₁ and the cooling water are If the difference between the temperature _{T 2} exceeds the stop setting value Δt (S1: YES, S2: NO), the compressor 25 of the cooling unit 3 is stopped (S6).

Specifically, when the stop set value Δt is set to 10 ° C., the chilled water temperature T ₁ is, for example, 15 ° C., and the cooling water temperature T ₂ is, for example, 3 ° C., the cooling unit 3 The compressor 25 is stopped.

  Then, the three-way valve 14 is determined when it is determined that the compressor 25 of the cooling unit 3 is stopped (S3: NO) and the pump 9 of the circulation unit 2 is operating (S7: YES). Based on the PID control by the sequence circuit 37, it is moved between the cooling position and the bypass position (S8).

  In this case, since the compressor 25 of the cooling unit 3 is stopped, the circulation of the refrigerant in the circulation line 23 is stopped. Therefore, the water supplied to the inlet 21 </ b> A on the cooled side of the evaporator 21 is not cooled by the evaporator 21.

  The water discharged to the downstream line 11 of the cold water return line 7 without being cooled by the evaporator 21 is partly exchanged through the upstream portion 12a of the cooling line 12 due to the movement of the three-way valve 14. The remaining portion is supplied to the cooled side inlet 8 </ b> A of the cooler 8, bypasses the heat exchanger 8 via the bypass line 13 and the downstream line 11 of the cold water return line 7, and is returned to the cold water tank 5. .

  A part of the water supplied to the inlet 8A on the cooled side of the heat exchanger 8 is cooled by heat exchange with the cooling water in the heat exchanger 8, and the downstream portion 12b of the cooling line 12 and the cold water return line 7 are cooled. To the cold water tank 5 through the downstream line 11.

  That is, by adjusting the position of the three-way valve 14 by PID control, the amount of water supplied to the heat exchanger 8 is adjusted, and the cooling degree of water in the heat exchanger 8 is adjusted.

According to this cooling system 1, as shown in FIG. 3, the temperature of the cooling water (cooling water temperature T ₂ ) supplied to the heat exchanger 8 for cooling the water in the cold water return line 7 is a cold water tank. When the temperature is lower than the water temperature in the water 5 (cold water temperature T ₁ ) and the difference between the cold water temperature T ₁ and the cooling water temperature T ₂ exceeds the stop set value Δt (S1: YES), cooling is performed. The operation of the unit 3 is stopped (S6).

Thus, the cooling water temperature T _2, when sufficiently low in cold water temperatures T _1, only the heat exchanger 8 can be cooled with water in the cold water return in line 7.

  As a result, energy saving can be further achieved as compared with the case where the water in the cold water return line 7 is cooled by the cooling unit 3.

Further, according to this cooling system 1, as shown in FIG. 3, the cooling water temperature T ₂ is lower than the cold water temperatures T _1, and the difference between the chilled water temperatures T ₁ and the cooling water temperature T ₂ is stopped setpoint When it is Δt or less (S1: NO, S2: NO), the three-way valve 14 is positioned at the cooling position (S4), and the water discharged from the evaporator 21 is introduced into the cooling line 12.

  Thereby, the water in the cold water return line 7 can be cooled by using the cooling unit 3 and the heat exchanger 8 together.

  As a result, the water in the cold water return line 7 can be cooled in a short time.

Further, according to this cooling system 1, as shown in FIG. 3, when the cooling water temperature _{T 2} is chilled water temperature above _{T 1} (S1: NO, S2: YES ), positions the three-way valve 14 to the bypass position (S5), water discharged from the evaporator 21 is introduced into the bypass line 13.

  Thereby, the water discharged from the evaporator 21 can flow around the heat exchanger 8.

As a result, when the temperature of the cooling water supplied to the heat exchanger 8 (cooling water temperature T ₂ ) is high, the water can be cooled by the cooling unit 3 without using the heat exchanger 8.

  Moreover, according to this cooling system 1, as shown in FIG. 3, in the state which operation | movement of the cooling unit 3 has stopped (S3: NO), based on PID control, the three-way valve 14 is made into a cooling position and a bypass position. (S8), the amount of water introduced into the cooling line 12 is adjusted.

  Thereby, when the operation of the cooling unit 3 is stopped, the water can be efficiently cooled using the heat exchanger 8.

  Moreover, according to this cooling system 1, the heat exchanger 8 is a heat exchanger which exchanges heat between liquids, and cooling water is water supplied from the outside.

Therefore, when the temperature of the cooling water supplied from the outside (cooling water temperature T ₂ ) is sufficiently lower than the temperature of the water in the cold water tank 5 (cooling water temperature T ₁ ), the cooling water is used, The water in the cold water return line 7 can be cooled.

As a result, further energy saving can be achieved.
Second Embodiment
FIG. 4 is a schematic configuration diagram showing a second embodiment of the temperature control system of the present invention.

  In the second embodiment, components similar to those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted.

  In the first embodiment, the cooling system 1 has only a function of cooling a molding die M as an example of an object.

  On the other hand, in the second embodiment, the temperature adjustment system 41 has a function of heating the molding die M in addition to a function of cooling the molding die M as an example of the object.

  The temperature control system 41 of 2nd Embodiment is provided with the 1st circulation unit 42, the 2nd circulation unit 43, the cooling unit 3, the heat exchanger 8, and the cooling water line 4 as shown in FIG. .

  The first circulation unit 42 includes a cold water tank 5 as an example of a storage unit, a supply upstream line 44, a return downstream line 45, a cooling upstream line 46, and a cooling downstream line 47.

  The cold water tank 5 is configured in the same manner as the cold water tank 5 of the first embodiment.

  The supply upstream line 44 is a pipe for supplying water in the cold water tank 5 to a circulation tank 49 (described later) of the second circulation unit 43. The upstream end of the supply upstream line 44 is connected to the cold water tank 5. Further, the downstream end of the supply upstream line 44 is connected to the center of the circulation tank 49 in the vertical direction.

  The return downstream line 45 is a pipe for returning water in the buffer tank 50 (described later) of the second circulation unit 43 to the cold water tank 5. The upstream end of the return downstream line 45 is connected to the upper end of the buffer tank 50. The downstream end of the return downstream line 45 is connected to the cold water tank 5.

  The cooling upstream line 46 is a pipe for supplying the water in the cold water tank 5 to the evaporator 21 of the cooling unit 3. The upstream end of the cooling upstream line 46 is connected to the cold water tank 5. The downstream end of the cooling upstream line 46 is connected to the inlet 21 </ b> A on the cooled side of the evaporator 21. The cooling upstream line 46 includes a pump 48.

  The pump 48 is interposed in the middle of the cold water upstream line 46. The pump 48 sends the water in the cold water tank 5 to the evaporator 21.

  The cooling downstream line 47 is a pipe for supplying water that has passed through the evaporator 21 to the supply upstream line 44. The upstream end of the cooling downstream line 47 is connected to the outlet 21 </ b> B on the cooled side of the evaporator 21. The downstream end of the cooling downstream line 47 is connected to the supply upstream line 44. The cooling downstream line 47 constitutes a third supply line together with the cooling upstream line 46. The cooling downstream line 47 includes a cooling line 12, a bypass line 13, and a three-way valve 14 as an example of a switching unit, similarly to the downstream line 11 of the first embodiment.

  The second circulation unit 43 includes a circulation tank 49, a buffer tank 50, a supply downstream line 51, and a return upstream line 52.

  The circulation tank 49 is a tank that stores water supplied from the cold water tank 5. The circulation tank 49 includes a heater 54.

  The heater 54 is disposed in the circulation tank 49. The heater 54 operates when heating the molding die M, and heats the water in the circulation tank 49.

  The buffer tank 50 is connected to the upper end portion of the circulation tank 49. The buffer tank 50 stores a part of the water in the circulation tank 49.

  The supply downstream line 51 is a pipe for supplying water in the circulation tank 49 to the molding die M. The upstream end of the supply downstream line 51 is connected to a circulation tank 49. Further, the downstream end portion of the supply downstream line 51 is connected to the inlet M1 of the molding die M. The supply downstream line 51 and the supply upstream line 44 constitute a first supply line. The supply downstream line 51 includes a pump 53.

  The pump 53 is interposed in the middle of the supply downstream line 51. The pump 53 sends the water in the circulation tank 49 to the molding die M.

  The return upstream line 52 is a pipe for returning the water that has cooled the molding die M to the circulation tank 49. The upstream end of the return upstream line 52 is connected to the outlet M2 of the molding die M. The downstream end of the return upstream line 52 is connected to the circulation tank 49. The return upstream line 52 and the return downstream line 45 constitute a return line.

  The cooling unit 3 is configured in the same manner as the cooling unit 3 of the first embodiment.

  The heat exchanger 8 is configured in the same manner as the heat exchanger 8 of the first embodiment, and is interposed in the middle of the cooling line 12 of the cooling downstream line 47.

  The cooling water line 4 is configured in the same manner as the cooling water line 4 of the first embodiment, and introduces cooling water to the cooling side of the heat exchanger 8 and the cooling side of the condenser 22.

Next, with reference to FIGS. 3 and 4, the cold water temperature control of the temperature adjustment system 41 of the second embodiment will be described. In the following description, the cold water temperature set value T ₀ and the stop set value Δt are the same as those in the first embodiment. In the second embodiment, the control unit 31 controls the operations of the compressor 25 of the cooling unit 3, the pump 48 and the three-way valve 14 of the first circulation unit 42, the pump 53 and the heater 54 of the second circulation unit 43. .

  When the molding die M is cooled by the temperature adjustment system 41, the heater 54 of the second circulation unit 43 is stopped.

  As in the cooling system 1 of the first embodiment, the temperature control program stored in the ROM of the control board 36 is executed by the CPU of the control board 36 (see FIG. 2).

Then, the cooling water temperature _{T 2} is lower than the cold water temperatures _{T 1,} and, if the difference between the chilled water temperatures _{T 1} and the cooling water temperature _{T 2} is less than stop setting value Δt (S1: NO, S2: NO), The three-way valve 14 is positioned at the cooling position when the sequence circuit 37 determines that the compressor 25 of the cooling unit 3 is in operation (S3: YES) (S4).

  When the pump 48 of the first circulation unit 42 is operated, the water in the cold water tank 5 is supplied by the pump 48 to the inlet 21A on the cooled side of the evaporator 21 via the cooling upstream line 46. .

  Then, the water supplied to the inlet 21A on the cooled side of the evaporator 21 is cooled by heat exchange with the refrigerant of the cooling unit 3, and the cooling downstream line 47 is passed through the outlet 21B on the cooled side of the evaporator 21. To be discharged.

  The water discharged to the cooling downstream line 47 is, as the three-way valve 14 is positioned at the cooling position, the inlet 8A of the cooled flow path 8E of the heat exchanger 8 via the upstream portion 12a of the cooling line 12. To be supplied.

  Then, the water supplied to the cooled side flow path 8E of the heat exchanger 8 is cooled by heat exchange with the cooling water in the heat exchanger 8, and the outlet 8B of the cooled side flow path 8E of the heat exchanger 8 is passed through. And then discharged to the downstream portion 12 b of the cooling line 12. That is, the cooling unit 3 and the heat exchanger 8 cool the water in the cold water tank 5 by cooling the water in the cooling upstream line 46 and the cooling downstream line 47. The water discharged to the downstream part 12 b of the cooling line 12 is supplied in the middle of the supply upstream line 44, a part is returned to the cold water tank 5, and the remaining part is supplied to the circulation tank 49. That is, the cooling upstream line 46 and the cooling downstream line 47 supply the water in the cold water tank 5 to the supply upstream line 44.

Incidentally, when the cooling water temperature _{T 2} is higher than the chilled water temperature _{T 1 (S1: NO, S2} : YES), the three-way valve 14, the sequence circuit 37, is positioned in the bypass position (S5).

  In this case, the water discharged to the cooling downstream line 47 bypasses the heat exchanger 8 via the bypass line 13 and is supplied along the supply upstream line 44.

When the cooling water temperature T ₂ is lower than the cold water temperature T ₁ by exceeding the stop set value Δt, that is, the cooling water temperature T ₂ is lower than the cold water temperature T ₁ , and the cold water temperature T ₁ and the cooling water are If the difference between the temperature _{T 2} exceeds the stop setting value Δt (S1: YES, S2: NO), the compressor 25 of the cooling unit 3 is stopped (S6).

  Then, the three-way valve 14 is determined when it is determined that the compressor 25 of the cooling unit 3 is stopped (S3: NO) and the pump 9 of the circulation unit 2 is operating (S7: YES). Based on the PID control by the sequence circuit 37, it is moved between the cooling position and the bypass position (S8).

  In this case, the water in the cold water tank 5 is not cooled by the evaporator 21 but is cooled only by the heat exchanger 8 as in the first embodiment.

  The water in the circulation tank 49 is supplied to the inlet M1 of the molding die M through the supply downstream line 51 by operating the pump 53 of the second circulation unit 43. Thereby, the molding die M is cooled by the water supplied to the inlet M1. Thereafter, the water that has cooled the molding die M is returned to the circulation tank 49 via the outlet M2 of the molding die M and the return upstream line 52.

  A part of the water in the circulation tank 49 is returned to the cold water tank 5 through the buffer tank 50 and the return downstream line 45, and the remaining part is circulated between the molding die M and the circulation tank 49. .

  Further, when the molding die M is heated by the temperature control system 41, the water in the circulation tank 49 is heated by the heater 54 and circulated between the molding die M and the circulation tank 49 as a heating medium. Is done.

Even in the temperature regulation system 41 of the second embodiment, as shown in FIG. 3, the cooling water temperature T ₂ is lower than the cold water temperatures T _1, and the difference between the chilled water temperatures T ₁ and the cooling water temperature T ₂ is stopped If it is equal to or less than the set value Δt, the three-way valve 14 is positioned at the cooling position and water is introduced into the cooling line 12.

  Thereby, the water in the cooling upstream line 46 and the cooling downstream line 47 can be cooled by using the cooling unit 3 and the heat exchanger 8 together.

  As a result, the water in the cooling upstream line 46 and the cooling downstream line 47 can be cooled in a short time.

Moreover, also in the temperature control system 41 of 2nd Embodiment, the effect similar to above-described 1st Embodiment can be acquired.
<Modification>
In the first embodiment and the second embodiment described above, measured by the cold water temperature sensor 32, the temperature of the water in the cold water tank 5, i.e., based on the cold water temperature T _1, the operation of the three-way valve 14 and the compressor 25 (Refer to FIG. 3, S1 and S2.)

On the other hand, in the modification, as shown in FIG. 5, the three-way valve 14 and the compressor are set based on an arbitrary set value input to the chilled water temperature indicator 35 by the operator's operation, that is, the chilled water temperature set value T _0. 25 operations can also be controlled (S10, S11). In this case, the cold water temperature set value T ₀ is an example of the first temperature.

According to this modification, control is performed based on the constant chilled water temperature set value T ₀ compared to the case where the chilled water temperature T ₁ is used as a reference, so that the operation control of the temperature control system can be simplified. it can.

DESCRIPTION OF SYMBOLS 1 Cooling system 3 Cooling unit 4 Cooling water line 5 Chilled water tank 6 Chilled water supply line 7 Chilled water return line 8 Heat exchanger 8E Cooled side flow path 8F Cooling side flow path 12 Cooling line 13 Bypass line 14 Three-way valve 31 Control part 32 Chilled water Temperature sensor 33 Cooling water temperature sensor 41 Temperature control system 44 First supply line 45 First return line 46 Cooling upstream line 47 Cooling downstream line 51 Second supply line 52 Second return line M Mold

Claims (5)

A reservoir for storing the first cooling medium;
First temperature detecting means for measuring a first temperature which is a temperature of the first cooling medium in the storage unit;
A first supply line for supplying the first cooling medium in the reservoir to a molding die ;
A return line for returning the first cooling medium that has cooled the molding die to the storage unit ;
A cooling unit and a heat exchanger to cool the first cooling medium of the previous SL return line,
A second supply line for supplying a second cooling medium for cooling the first cooling medium to the heat exchanger;
Second temperature detection means for measuring a second temperature, which is a temperature of the second cooling medium in the second supply line;
A control unit for controlling the operation of the cooling unit,
The heat exchanger includes a high temperature side channel through which the first cooling medium flows, and a low temperature side channel through which the second cooling medium flows,
The return line is
A cooling line connected to the high temperature side flow path;
A bypass line that bypasses the heat exchanger;
Switching means movable between a first position for opening the cooling line and closing the bypass line and a second position for opening the bypass line and closing the cooling line;
With
The controller is
When the second temperature is lower than the first temperature and the difference between the first temperature and the second temperature is less than or equal to a predetermined value, the cooling unit is operated and the switching means is In one position,
When the second temperature is lower than the first temperature and a difference between the first temperature and the second temperature exceeds a predetermined value, the operation of the cooling unit is stopped. Temperature control system.   A reservoir for storing the first cooling medium;
  First temperature detecting means for measuring a first temperature which is a temperature of the first cooling medium in the storage unit;
  A first supply line for supplying the first cooling medium in the reservoir to a molding die;
  A return line for returning the first cooling medium that has cooled the molding die to the storage unit;
  A third supply line for supplying the first cooling medium in the reservoir to the first supply line;
  A cooling unit and a heat exchanger for cooling the first cooling medium in the reservoir by cooling the first cooling medium in the third supply line;
  A second supply line for supplying a second cooling medium for cooling the first cooling medium to the heat exchanger;
  Second temperature detection means for measuring a second temperature, which is a temperature of the second cooling medium in the second supply line;
  A control unit for controlling the operation of the cooling unit;
With
  The heat exchanger includes a high temperature side channel through which the first cooling medium flows, and a low temperature side channel through which the second cooling medium flows,
  The third supply line is
    A cooling line connected to the high temperature side flow path;
    A bypass line that bypasses the heat exchanger;
    Switching means movable between a first position for opening the cooling line and closing the bypass line and a second position for opening the bypass line and closing the cooling line;
With
  The controller is
    When the second temperature is lower than the first temperature and the difference between the first temperature and the second temperature is less than or equal to a predetermined value, the cooling unit is operated and the switching means is In one position,
    When the second temperature is lower than the first temperature and a difference between the first temperature and the second temperature exceeds a predetermined value, the operation of the cooling unit is stopped. Temperature control system. Wherein, when said second temperature is the first temperature or more, along with operating the cooling unit, characterized in that to position the switching means to the second position, it was or claim 1 Is the temperature control system according to 2. The control unit is configured to move the switching unit between the first position and the second position based on PID control in a state where the operation of the cooling unit is stopped. The temperature control system as described in any one of Claims 1-3 . The heat exchanger is a heat exchanger that exchanges heat between liquids,
The temperature control system according to any one of claims 1 to 4, wherein the second cooling medium is water supplied from the outside.

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