Temperature regulating fluid circulation device and temperature regulating fluid circulation system

Abstract

A temperature-regulated fluid circulation device according to one embodiment includes: a flow path for circulating a fluid, temperature-regulated by a temperature regulating unit, through a fluid supply destination; a three-way valve disposed in the flow path downstream of the fluid supply destination and upstream of the temperature regulating position of the temperature regulating unit, with the flow path comprising a portion between two of the three ports; and a bypass flow path branching from a position in the flow path downstream of the temperature regulating position of the temperature regulating unit and upstream of the fluid supply destination, and connected to the remaining one of the three ports of the three-way valve. A pressure sensor detects the pressure of the fluid flowing in the flow path downstream of the fluid supply destination and upstream of the three-way valve. Furthermore, the opening of the three-way valve is controlled so that the pressure of the fluid detected by the pressure sensor reaches a specified target pressure.

Description

Technical Field

[0001] One embodiment of the present invention relates to a temperature-controlled fluid circulation device and a temperature-controlled fluid circulation system for conveying a temperature-controlled fluid to a fluid supply target or a temperature-controlled target and for re-controlling the temperature of the fluid having passed through the fluid supply target or the temperature-controlled target. Background Art

[0002] The following fluid circulation device is known: a fluid such as brine that has been temperature-controlled by a refrigeration device having a compressor, a condenser, an expansion valve, and an evaporator is transported to the side of a temperature-controlled object, and the fluid that has passed through the temperature-controlled object is temperature-controlled again by the refrigeration device (for example, Patent Document 1: Japanese Patent Application Publication JP2014-145565A).

[0003] Japanese Patent Application Publication No. JP2013-105359A (Patent Document 2) discloses a system comprising multiple fluid circulation devices as described above. In the system disclosed in JP2013-105359A, the temperatures of the fluids controlled by the two fluid circulation devices are different, allowing the fluids delivered by the two fluid circulation devices to the temperature-controlled object to be mixed in front of the temperature-controlled object. This allows the temperature of the fluid delivered to the temperature-controlled object to be quickly adjusted to the desired temperature. Summary of the Invention

[0004] In a fluid circulation system such as the one described above, the temperature of the fluid returning from the temperature-controlled target may fluctuate significantly, depending on the state of the temperature-controlled target. Consequently, the pressure of the fluid downstream of the temperature-controlled target may also fluctuate significantly. Such pressure fluctuations may affect the flow of fluid upstream of the temperature-controlled target, potentially disrupting the flow of the fluid and reducing temperature control accuracy.

[0005] Furthermore, in the system disclosed in Patent Document 2, the fluid returning from the temperature-controlled object is distributed to two fluid circulation devices that regulate the fluid to different temperatures. In this case, the pressure of the fluid returning from the temperature-controlled object may affect the two fluid circulation devices differently. In this case, the ratio of the fluids mixed in front of the temperature-controlled object may deviate significantly from the target value, raising the concern that temperature regulation accuracy may be significantly reduced.

[0006] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a temperature control fluid circulation device and a temperature control fluid circulation system capable of improving the accuracy of temperature control based on the fluid by improving the stability of the circulation state of the fluid.

[0007] A temperature-regulated fluid circulation device according to one embodiment of the present invention includes: a flow path for circulating fluid, temperature-regulated by a temperature regulating unit, through a fluid supply destination; a three-way valve disposed in the flow path downstream of the fluid supply destination and upstream of the temperature regulation position of the temperature regulating unit, with the portion between two of three ports constituting a portion of the flow path; a bypass flow path branching from a position in the flow path downstream of the temperature regulation position of the temperature regulating unit and upstream of the fluid supply destination, and connected to the remaining one of the three ports of the three-way valve, which is different from the two ports constituting a portion of the flow path; a pressure sensor for detecting the pressure of the fluid flowing in the flow path downstream of the fluid supply destination and upstream of the three-way valve; and a controller for controlling the three-way valve. The controller controls the opening of the three-way valve so that the pressure of the fluid detected by the pressure sensor reaches a predetermined target pressure.

[0008] In addition, a temperature-regulating fluid circulation system according to one embodiment of the present invention comprises: a valve unit; a first temperature-regulating fluid circulation device having a first side flow path, a first side three-way valve, a first side bypass flow path, and a first side pressure sensor, wherein the first side flow path circulates the fluid temperature-regulated by the first side temperature regulating portion through the valve unit, the first side three-way valve being arranged in the first side flow path at a position downstream of the valve unit and upstream of a temperature regulating position of the first side temperature regulating portion, and a portion between two of the three ports. The first side bypass flow path branches off from a position downstream of the temperature adjustment position of the first side temperature adjustment portion and upstream of the valve unit in the first side flow path, and is connected to the remaining one port of the three ports of the first side three-way valve that is different from the two ports that constitute a part of the first side flow path. The first side pressure sensor detects the pressure of the fluid flowing in the first side flow path at a position downstream of the valve unit and upstream of the first side three-way valve; The second temperature-regulating fluid circulation device comprises a second side flow path, a second side three-way valve, a second side bypass flow path and a second side pressure sensor. The second side flow path circulates the fluid after temperature regulation by the second side temperature regulating unit through the valve unit. The second side three-way valve is arranged at a position downstream of the valve unit in the second side flow path and upstream of the temperature regulation position of the second side temperature regulating unit. A portion between two of the three ports constitutes a part of the second side flow path. The second side bypass flow path is connected to the second side flow path. The invention further comprises a first side flow path and a second side flow path, wherein the first side flow path is branched at a position downstream of the temperature control position of the second side temperature control portion and upstream of the valve unit, and is connected to the remaining one of the three ports of the second side three-way valve, which is different from the two ports constituting a portion of the second side flow path. The second side pressure sensor detects the pressure of the fluid flowing in the second side flow path downstream of the valve unit and upstream of the second side three-way valve; and a controller controls the first side three-way valve and the second side three-way valve. The valve unit transfers fluid received from the first temperature control fluid circulation device, fluid received from the second temperature control fluid circulation device, or a mixture of fluids received from the first temperature control fluid circulation device and fluids received from the second temperature control fluid circulation device to a temperature control target, and returns the fluid passing through the temperature control target to the first side flow path and / or the second side flow path. Moreover, the controller controls the opening of the three-way valve on the first side in such a manner that the pressure of the fluid detected by the first side pressure sensor becomes the specified first side target pressure, and controls the opening of the three-way valve on the second side in such a manner that the pressure of the fluid detected by the second side pressure sensor becomes the specified second side target pressure.

[0009] According to one embodiment of the present invention, the temperature control accuracy based on the fluid can be improved by improving the stability of the circulation state of the fluid. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 This is a diagram showing a schematic configuration of a temperature control fluid circulation device according to a first embodiment of the present invention.

[0011] Figure 2 This is a flowchart for explaining an example of the operation of the temperature control fluid circulation device according to the first embodiment.

[0012] Figure 3 This is a diagram showing a schematic configuration of a temperature control fluid circulation system according to a second embodiment of the present invention.

[0013] Figure 4 This is a flowchart illustrating an example of the operation of the temperature control fluid circulation system according to the second embodiment.

[0014] Figure 5 This is a diagram showing a schematic configuration of a temperature control fluid circulation system according to a third embodiment of the present invention. DETAILED DESCRIPTION

[0015] Hereinafter, the modes of each embodiment of the present invention will be described.

[0016] <First embodiment>

[0017] Figure 1 This figure schematically illustrates the configuration of a temperature-controlled fluid circulation device 1 according to a first embodiment of the present invention. The temperature-controlled fluid circulation device 1 includes a flow path 3 that circulates a fluid, temperature-controlled by a temperature-regulating unit 2, through a temperature-controlled object T to which the fluid is supplied. As an example, the temperature-regulating unit 2 is an evaporator of a refrigerator, but other cooling devices may also be used. Furthermore, when heating the temperature-controlled object T, the temperature-regulating unit 2 may be, for example, an electric heater.

[0018] The fluid circulating in the flow path 3 is, for example, salt water, but may also be other fluids such as water. The flow path 3 in this embodiment has an upstream end 3U and a downstream end 3D, each connected to the temperature-controlled object T. The fluid, temperature-controlled by the temperature control unit 2, is supplied to the temperature-controlled object T from the downstream end 3D of the flow path 3. The fluid, having passed through the temperature-controlled object T, returns to the flow path 3 from the upstream end 3U of the flow path 3.

[0019] A three-way valve 4 is disposed in the flow path 3 at a position downstream of the temperature control target T and upstream of the temperature adjustment position of the temperature adjustment unit 2. The three-way valve 4 has a first port 4A, a second port 4B, and a third port 4C, and the portion between the first port 4A and the third port 4C constitutes a portion of the flow path 3.

[0020] The second port 4B of the three-way valve 4 is connected to the bypass flow path 5. The bypass flow path 5 branches from a position downstream of the temperature adjustment position of the temperature adjustment unit 2 and upstream of the temperature control target T in the flow path 3.

[0021] The three-way valve 4 is a proportional three-way valve having a stepping motor 4M as an actuator for driving the valve element. The three-way valve 4 uses the stepping motor 4M to adjust the position of the valve element (not shown). The ratio between the flow rate of the fluid flowing from the first port 4A to the third port 4C and the flow rate of the fluid flowing from the second port 4B to the third port 4C varies depending on the position of the valve element.

[0022] When the first port 4A and the third port 4C are fully opened, the fluid temperature-regulated by the temperature regulating unit 2 flows entirely toward the temperature-controlled object T, and the fluid is not bypassed by the bypass flow path 5 without passing through the temperature-controlled object T. On the other hand, when the second port 4B and the third port 4C are fully opened, the fluid temperature-regulated by the temperature regulating unit 2 does not flow within the temperature-controlled object T, and is bypassed by the bypass flow path 5 without passing through the temperature-controlled object T.

[0023] A tank 6 is located downstream of the three-way valve 4 in the flow path 3 and upstream of the temperature control position of the temperature control unit 2. Tank 6 also forms part of the flow path 3. Tank 6 stores only a certain amount of fluid. In this embodiment, a pump 7 is located within tank 6 to provide a driving force for circulating the fluid in the flow path 3. In this embodiment, when the temperature control fluid circulation device 1 is started, pump 7 is driven with a constant driving force.

[0024] In addition, in the present embodiment, the above-mentioned fluid is a liquid. Moreover, a liquid level maintaining mechanism 8 is connected to the tank 6 to maintain the height of the liquid level of the stored liquid, i.e., the fluid, at a constant level. In the present embodiment, the liquid level maintaining mechanism 8 is a container that stores a certain amount of liquid (the same liquid as the liquid to be circulated), and the piping component connected to the liquid level storage position in the container is connected to the liquid level storage position in the tank 6. In addition, the liquid level storage position is a position lower than the height of the liquid level when a certain amount of liquid is stored in the tank 6 or the above-mentioned container. The amount of liquid stored in the tank 6 or the above-mentioned container is predetermined.

[0025] When the pressure of the fluid on the upstream side of the tank 6 increases and the liquid level in the tank 6 tends to rise, the liquid level maintaining mechanism 8 supplies the liquid in the tank 6 to the liquid level maintaining mechanism 8. On the other hand, when the pressure of the fluid on the upstream side of the tank 6 decreases and the liquid level in the tank 6 tends to decrease, the liquid flows from the liquid level maintaining mechanism 8 into the tank 6. In this way, the liquid level maintaining mechanism 8 has the function of maintaining the liquid level in the tank 6 constant, thereby relieving pressure fluctuations in the portion of the flow path 3 upstream of the tank 6.

[0026] The temperature-controlled fluid circulation device 1 also includes a pressure sensor 9P and a temperature sensor 9T, and a controller 100 electrically connected to these sensors. The pressure sensor 9P detects the pressure of the fluid flowing in the flow path 3, downstream of the temperature-controlled target T and upstream of the three-way valve 4. The temperature sensor 9T detects the temperature of the temperature-controlled target T.

[0027] The controller 100 may be configured, for example, by a computer having a CPU, ROM, etc. In this case, various processes are executed according to the programs stored in the ROM. Alternatively, the controller 100 may be configured by another processor or circuit (e.g., an FPGA (Field Programmable Gate Array)).

[0028] The controller 100 receives information related to the fluid pressure from the pressure sensor 9P and information related to the temperature of the temperature-controlled object T from the temperature sensor 9T. Based on this information, the controller 100 controls the opening of the three-way valve 4 so that the fluid pressure detected by the pressure sensor 9P reaches a specified target pressure. The target pressure is input into the controller 100 by the user.

[0029] In more detail, the controller 100 of this embodiment performs feedback control on the opening of the three-way valve 4 based on the difference between the pressure detected by the pressure sensor 9P and the target pressure, so that the pressure of the fluid detected by the pressure sensor 9P becomes the specified target pressure, and performs feedforward control on the opening of the three-way valve 4 based on the temperature information from the temperature sensor 9T.

[0030] The feedforward control is executed when it is determined that the absolute value of the rate of change of the temperature of the temperature-controlled object T is greater than a threshold value. In the feedforward control, the opening of the three-way valve 4 is changed according to the operation amount corresponding to the magnitude of the absolute value of the rate of change.

[0031] More specifically, when the absolute value of the rate of change of the temperature of the temperature-controlled object T is greater than or equal to a threshold value indicating a temperature increase, the opening of the three-way valve 4 is changed according to an operation amount proportional to the magnitude of the absolute value of the rate of change, thereby increasing the openings of the first port 4A and the third port 4C. On the other hand, when the absolute value of the rate of change of the temperature of the temperature-controlled object T is greater than or equal to a threshold value indicating a temperature decrease, the three-way valve 4 is operated according to an operation amount proportional to the magnitude of the absolute value of the rate of change, thereby decreasing the openings of the first port 4A and the third port 4C.

[0032] The temperature change rate refers to the amount of temperature change per unit time. The temperature change rate is calculated sequentially by calculating a moving average of the temperature per unit time and dividing the difference between the most recent moving average and the previously calculated moving average by the unit time. The time range for calculating the moving average may also be, for example, a time range that looks back a unit time from the time the rate of change is calculated. Furthermore, it is preferred that the temperature sensor 9T detect temperatures at at least five points within the time range for calculating the moving average.

[0033] The length of the unit time is not particularly limited. If it is too short, the accuracy of the rate of change calculation may be reduced due to the influence of noise components. If it is too long, effective feedforward control may not be achieved. Therefore, the time interval (unit time) for specifying the rate of change may be set, for example, between 0.5 seconds and 3 seconds.

[0034] Figure 2 This is a flowchart for explaining an example of the operation of the temperature control fluid circulation device 1. Figure 2 An example of the operation of the temperature control fluid circulation device 1 will be described.

[0035] As an example, the operation described here begins after the temperature-controlled fluid circulation device 1 starts operating and the temperature of the temperature-controlled object T reaches the target temperature. At this point, the three-way valve 4 is controlled to a predetermined reference opening, which is an intermediate opening between fully closed and fully open. Furthermore, for example, when the temperature sensor 9T detects that the temperature of the temperature-controlled object T has reached the target temperature, the controller 100 first monitors, based on information from the temperature sensor 9T, whether the absolute value of the rate of change of the temperature of the temperature-controlled object T (hereinafter, the "temperature change rate") is above a threshold value in step 101.

[0036] If it is determined in step S101 that the absolute value of the temperature change rate is greater than the threshold value, the controller 100 changes the opening of the three-way valve 4 in step S102 according to the operation amount corresponding to the magnitude of the absolute value of the temperature change rate, and then transfers the processing to step S103. On the other hand, if it is not determined in step S101 that the absolute value of the temperature change rate is greater than the threshold value, the processing transfers to step S103.

[0037] Next, in step S103, the controller 100 performs feedback control on the opening of the three-way valve 4 based on the difference between the pressure detected by the pressure sensor 9P and the target pressure, so that the pressure of the fluid detected by the pressure sensor 9P reaches the specified target pressure. Next, in step S104, the controller 100 detects whether an operation stop command has been generated. If so, the controller 100 stops the operation of the temperature-regulating fluid circulation device 1. If not, the process returns to step S101.

[0038] In the embodiment described above, the pressure of the fluid flowing out of the temperature-controlled object T can be maintained at a desired value. This improves the stability of the circulation state of the fluid in the flow path 3 and thereby improves the accuracy of temperature control by the fluid.

[0039] In particular, by combining feedback control toward the target pressure using the pressure sensor 9P with feedforward control based on the rate of change of the temperature of the temperature-controlled object T, the reliability and speed of control toward the target pressure can be improved. Furthermore, by maintaining the liquid level in the tank 6 using the liquid level maintaining mechanism 8, pressure fluctuations in the portion of the flow path 3 upstream of the tank 6, i.e., pressure fluctuations in the fluid flowing out of the temperature-controlled object T, are mitigated. This allows for improved stability of the fluid circulation state using a simple mechanical structure, thereby enhancing device reliability.

[0040] <Second embodiment>

[0041] Next, the temperature control fluid circulation system S1 according to the second embodiment will be described. Figure 3 1 is a schematic diagram of a temperature control fluid circulation system S1. In this embodiment, the same components as those in the first embodiment are denoted by the same reference numerals.

[0042] The temperature control fluid circulation system S1 includes a first temperature control fluid circulation device 10 , a second temperature control fluid circulation device 20 , a valve unit 50 , and a controller 100 .

[0043] exist Figure 3 In the figure, the main portions of the first temperature control fluid circulation device 10 and the second temperature control fluid circulation device 20 are enclosed by two-dot chain lines. The first temperature control fluid circulation device 10 and the second temperature control fluid circulation device 20 have basically the same structure as the temperature control fluid circulation device 1 of the first embodiment. Below, the first temperature control fluid circulation device 10 and the second temperature control fluid circulation device 20 are first described.

[0044] First, the first temperature-regulated fluid circulation device 10 includes a first side flow path 13 that circulates the fluid, temperature-regulated by the first side temperature regulating unit 12, through the valve unit 50, which is the fluid supply target. As an example, the first side temperature regulating unit 12 is an evaporator of a refrigerator, but it can also be other cooling equipment.

[0045] The fluid circulating in the first side flow path 13 is, for example, salt water, but may also be other fluids such as water. In this embodiment, the first side flow path 13 has an upstream end 13U and a downstream end 13D, each of which is connected to the valve unit 50. The fluid temperature-regulated by the first side temperature regulating unit 12 is supplied to the valve unit 50 from the downstream end 13D of the first side flow path 13. Although the details will be described later, the valve unit 50 supplies the received fluid to the temperature-controlled object T. Moreover, in this embodiment, the fluid flowing out of the temperature-controlled object T can be returned to the first side flow path 13 from the upstream end 13U via the valve unit 50. However, in this example, when the fluid from the first temperature-regulated fluid circulation device 10 is not caused to flow into the temperature-controlled object T via the valve unit 50, the fluid from the temperature-controlled object T is not returned to the first side flow path 13 via the valve unit 50.

[0046] A first-side three-way valve 14 is disposed downstream of the valve unit 50 in the first-side flow path 13 and upstream of the temperature adjustment position of the first-side temperature adjustment unit 12. The first-side three-way valve 14 has a first-side first port 14A, a first-side second port 14B, and a first-side third port 14C. The portion between the first-side first port 14A and the first-side third port 14C constitutes a portion of the first-side flow path 13.

[0047] The first-side second port 14B of the first-side three-way valve 14 is connected to a first-side bypass flow path 15 that branches from a position in the first-side flow path 13 downstream of the temperature adjustment position of the first-side temperature adjustment unit 12 and upstream of the valve unit 50 .

[0048] The first-side three-way valve 14 is a proportional three-way valve having a first-side stepping motor 14M as an actuator for driving the valve element. The first-side three-way valve 14 adjusts the position of the valve element (not shown) by the first-side stepping motor 14M. The ratio between the flow rate of the fluid flowing from the first-side first port 14A to the first-side third port 14C and the flow rate of the fluid flowing from the first-side second port 14B to the first-side third port 14C varies according to the position of the valve element.

[0049] Furthermore, a first side tank 16 is disposed in the first side flow path 13, downstream of the first side three-way valve 14 and upstream of the temperature control position of the first side temperature control unit 12. This first side tank 16 also constitutes a portion of the first side flow path 13. The first side tank 16 stores only a certain amount of liquid, i.e., fluid. In this embodiment, a first side pump 17 is disposed within the first side tank 16 to provide a driving force for circulating the fluid in the first side flow path 13. In this embodiment, when operation of the temperature control fluid circulation system S1 is initiated, the first side pump 17 is driven with a constant driving force.

[0050] The first temperature-regulating fluid circulation device 10 also includes a first-side pressure sensor 19P, which is electrically connected to the controller 100. The first-side pressure sensor 19P detects the pressure of the fluid flowing through the first-side flow path 13 at a position downstream of the valve unit 50 and upstream of the first-side three-way valve 14.

[0051] Next, the second temperature-regulating fluid circulation device 20 also includes a second side flow path 23 that circulates the fluid, temperature-regulated by the second side temperature-regulating unit 22, through the valve unit 50 to which the fluid is supplied. As an example, the second side temperature-regulating unit 22 is also an evaporator of a refrigerator, but it can also be another cooling device. However, the second side temperature-regulating unit 22 cools the fluid to a temperature lower than that of the first side temperature-regulating unit 12. That is, in this embodiment, the temperature-regulating fluid circulation system S1 is operated so that the temperature of the fluid temperature-regulated by the first side temperature-regulating fluid circulation device 10 is higher than the temperature of the fluid temperature-regulated by the second side temperature-regulating fluid circulation device 20.

[0052] The fluid circulating in the second side flow path 23 is the same fluid as the fluid circulating in the first side flow path 13, for example, salt water, but may also be another fluid such as water. In this embodiment, the second side flow path 23 also has an upstream end 23U and a downstream end 23D, each of which is connected to the valve unit 50. The fluid, temperature-regulated by the second side temperature regulating unit 22, is supplied to the valve unit 50 from the downstream end 23D of the second side flow path 23. Furthermore, as described above, in this embodiment, the valve unit 50 supplies the received fluid to the temperature-controlled object T. Furthermore, as described above, fluid flowing out of the temperature-controlled object T can be returned to the second side flow path 23 from the upstream end 23U via the valve unit 50. However, if fluid from the second temperature-regulated fluid circulation device 20 is not supplied to the temperature-controlled object T via the valve unit 50, fluid from the temperature-controlled object T will not be returned to the second side flow path 23 via the valve unit 50.

[0053] A second side three-way valve 24 is also arranged at a position downstream of the valve unit 50 in the second side flow path 23 and upstream of the temperature control position of the second side temperature control part 22. The second side three-way valve 24 has a second side first port 24A, a second side second port 24B and a second side third port 24C. The portion between the second side first port 24A and the second side third port 24C constitutes a portion of the second side flow path 23.

[0054] The second side second port 24B of the second side three-way valve 24 is connected to a second side bypass flow path 25 that branches from a position in the second side flow path 23 downstream of the temperature adjustment position of the second side temperature adjustment unit 22 and upstream of the valve unit 50 .

[0055] The second-side three-way valve 24 is a proportional three-way valve having a second-side stepping motor 24M as an actuator for driving the valve element. The second-side three-way valve 24 adjusts the position of the valve element (not shown) by the second-side stepping motor 24M. The ratio between the flow rate of the fluid flowing from the second-side first port 24A to the second-side third port 24C and the flow rate of the fluid flowing from the second-side second port 24B to the second-side third port 24C varies according to the position of the valve element.

[0056] A second-side tank 26 is disposed in the second-side flow path 23, downstream of the second-side three-way valve 24 and upstream of the temperature adjustment position of the second-side temperature adjustment unit 22. The second-side tank 26 also constitutes a portion of the second-side flow path 23. The second-side tank 26 stores a certain amount of liquid, i.e., fluid. A second-side pump 27 is disposed within the second-side tank 26 to provide a driving force for circulating the fluid in the second-side flow path 23. When the temperature adjustment fluid circulation system S1 is activated, the second-side pump 27 is also driven with a constant driving force.

[0057] The second temperature control fluid circulation device 20 also includes a second side pressure sensor 29P, which is electrically connected to the controller 100. The second side pressure sensor 29P detects the pressure of the fluid flowing through the second side flow path 23 at a position downstream of the valve unit 50 and upstream of the second side three-way valve 24.

[0058] In this embodiment, the first and second temperature-regulating fluid circulation devices 10 and 20 circulate the same liquid. The liquid storage position of the first side tank 16 and the liquid storage position of the second side tank 26 are connected by a piping member 30. The liquid level storage position is a position below the liquid level when a certain amount of liquid is stored in the tank. The amount of liquid stored in the tank is predetermined.

[0059] The piping assembly 30 allows liquid to flow between the first side tank 16 and the second side tank 26. This equalizes the liquid levels in the first side tank 16 and the second side tank 26, making it possible to equalize the pressures of the respective stored liquids. In this embodiment, the valve unit 50 can be used to mix the liquid from the first temperature control fluid circulation device 10 and the liquid from the second temperature control fluid circulation device 20 and supply them to the temperature-controlled target T. By equalizing the pressures of the two liquids using the piping assembly 30, the temperature of the mixed liquid can be easily controlled to a desired temperature.

[0060] Next, the valve unit 50 will be described. The valve unit 50 is configured to transport fluid received from the first temperature control fluid circulation device 10, fluid received from the second temperature control fluid circulation device 20, or a mixture of the fluid received from the first temperature control fluid circulation device 10 and the fluid received from the second temperature control fluid circulation device 20 to the temperature control target T, and to return the fluid that has passed through the temperature control target T to the first side flow path 13 and / or the second side flow path 23.

[0061] The valve unit 50 in this embodiment includes a valve unit-side supply three-way valve 51 and a valve unit-side return three-way valve 52. The valve unit-side supply three-way valve 51 includes a first receiving port 51A, a second receiving port 51B, and a supply port 51C. The first receiving port 51A is connected to the downstream end 13D of the first-side flow path 13 of the first temperature control fluid circulation device 10, and the second receiving port 51B is connected to the downstream end 23D of the second-side flow path 23 of the second temperature control fluid circulation device 20. Furthermore, the supply port 51C is connected to the temperature-controlled object T via a flow path.

[0062] The three-way valve 51 provided on the valve unit side is a proportional three-way valve having a stepping motor 51M as an actuator to drive the valve element. The three-way valve 51 provided on the valve unit side adjusts the position of the valve element (not shown) by the stepping motor 51M. This allows the mixing ratio of the fluid received from the first temperature control fluid circulation device 10 at the first receiving port 51A and the fluid received from the second temperature control fluid circulation device 20 at the second receiving port 51B to be varied according to the position of the valve element, and the fluid then flows out of the supply port 51C.

[0063] On the other hand, the valve unit-side return three-way valve 52 includes a return port 52A, a first distribution port 52B, and a second distribution port 52C. The return port 52A is connected to the temperature-controlled object T via a flow path. Furthermore, the first distribution port 52B is connected to the upstream end 13U of the first-side flow path 13 of the first temperature control fluid circulation device 10, and the second distribution port 52C is connected to the upstream end 23U of the second-side flow path 23 of the second temperature control fluid circulation device 20.

[0064] The valve unit-side return three-way valve 52 is also a proportional three-way valve having a stepping motor 52M as an actuator for driving the valve element. The valve unit-side return three-way valve 52 adjusts the position of the valve element (not shown) using the stepping motor 52M. This allows the fluid received at the return port 52A to be returned to the first temperature control fluid circulation device 10 and the second temperature control fluid circulation device 20 at a predetermined ratio based on the position of the valve element.

[0065] In this embodiment, the valve unit-side supply three-way valve 51 and the valve unit-side return three-way valve 52 are identical in form and size. Furthermore, the opening degrees of the valve unit-side supply three-way valve 51 and the valve unit-side return three-way valve 52 are controlled by the controller 100. Specifically, the valve unit-side supply three-way valve 51 and the valve unit-side return three-way valve 52 are controlled by the controller 100 to have the same opening degrees.

[0066] The temperature-regulating fluid circulation system S1 in this embodiment also includes a valve unit-side pressure sensor 54 for detecting the pressure of the fluid in the valve unit-side supply three-way valve 51 (specifically, the pressure of the fluid flowing out of the supply port 51C), and a temperature sensor 55 for detecting the temperature of the temperature-controlled object T. The controller 100 is configured to receive information related to the fluid from the first-side pressure sensor 19P, the second-side pressure sensor 29P, and the valve unit-side pressure sensor 54, and to receive information related to the temperature of the temperature-controlled object T from the temperature sensor 55.

[0067] The following describes the controller 100 of this embodiment. The controller 100 controls the opening of the first-side three-way valve 14 so that the pressure of the fluid detected by the first-side pressure sensor 19P reaches a specified first-side target pressure, and controls the opening of the second-side three-way valve 24 so that the pressure of the fluid detected by the second-side pressure sensor 29P reaches a specified second-side target pressure. The target pressures are input into the controller 100 by the user.

[0068] More specifically, the controller 100 of this embodiment performs feedback control on the opening of the first-side three-way valve 14 based on the difference between the fluid pressure detected by the first-side pressure sensor 19P and the first-side target pressure, so that the fluid pressure detected by the first-side pressure sensor 19P reaches the specified first-side target pressure. Furthermore, the controller 100 performs feedback control on the opening of the second-side three-way valve 24 based on the difference between the fluid pressure detected by the second-side pressure sensor 29P and the second-side target pressure, so that the fluid pressure detected by the second-side pressure sensor 29P reaches the specified second-side target pressure. Furthermore, the controller 100 performs feedforward control on the openings of each of the first-side three-way valve 14 and the second-side three-way valve 24 based on information on the fluid pressure from the valve unit-side pressure sensor 54.

[0069] The above-mentioned feedforward control is performed when it is determined based on information from the pressure sensor 54 on the valve unit side that the absolute value of the rate of change of the pressure in the three-way valve 51 provided by the valve unit side is greater than a threshold value. In this feedforward control, the opening of the three-way valve 14 on the first side and the three-way valve 24 on the second side are changed according to the operating amount corresponding to the size of the absolute value of the above-mentioned rate of change.

[0070] In detail, when the absolute value of the rate of change of pressure in the three-way valve 51 provided on the valve unit side is greater than the threshold value on the rising side, the opening of the three-way valve 14 on the first side is changed in a manner that increases the opening of the first port 14A on the first side and the third port 14C on the first side, and the opening of the three-way valve 24 on the second side is changed in a manner that increases the opening of the first port 24A on the second side and the third port 24C on the second side.

[0071] On the other hand, when the absolute value of the rate of change of the pressure in the three-way valve 51 provided on the valve unit side is greater than the threshold value on the descending side, the opening of the three-way valve 14 on the first side is changed in a manner that reduces the opening of the first port 14A on the first side and the third port 14C on the first side, and the opening of the three-way valve 24 on the second side is changed in a manner that reduces the opening of the first port 24A on the second side and the third port 24C on the second side.

[0072] The pressure change rate refers to the amount of pressure change per unit time. The pressure change rate is calculated sequentially by calculating a moving average of the pressure per unit time and dividing the difference between the most recent moving average of the pressure and the previously calculated moving average of the pressure by the unit time. The time range for calculating the moving average may, for example, be a time range that looks back a unit time from the time the rate of change is calculated. Furthermore, it is preferred that the valve unit-side pressure sensor 54 detects pressure at at least five points within the time range for calculating the moving average.

[0073] Figure 4 This is a flowchart illustrating an example of the operation of the temperature control fluid circulation system S1. Figure 4 An example of the operation of the temperature control fluid circulation system S1 will be described.

[0074] As an example, the operations described here begin after the temperature control fluid circulation system S1 begins operating and the temperature of the temperature control object T reaches the target temperature. At this point, the first-side three-way valve 14 and the second-side three-way valve 24 are controlled to predetermined reference openings, each of which is an intermediate opening between fully closed and fully open. Furthermore, for example, when the temperature sensor 55 detects that the temperature control object T has reached the target temperature, the controller 100 first monitors, in step 201, whether the absolute value of the rate of change of pressure (hereinafter, "pressure change rate") provided within the three-way valve 51 on the valve unit side, based on information from the valve unit-side pressure sensor 54, is above a threshold.

[0075] If it is determined in step S201 that the absolute value of the pressure change rate is greater than the threshold value, the controller 100 changes the openings of the first-side three-way valve 14 and the second-side three-way valve 24 in step S202 according to the operation amount corresponding to the magnitude of the absolute value of the pressure change rate, and then transfers the process to step S203. On the other hand, if it is not determined in step S201 that the absolute value of the pressure change rate is greater than the threshold value, the process transfers to step S203.

[0076] Then, in step S203, the controller 100 performs feedback control on the opening of the first side three-way valve 14 based on the difference between the pressure of the fluid detected by the first side pressure sensor 19P and the first side target pressure, so that the pressure of the fluid detected by the first side pressure sensor 19P becomes the specified first side target pressure, and performs feedback control on the opening of the second side three-way valve 24 based on the difference between the pressure of the fluid detected by the second side pressure sensor 29P and the second side target pressure, so that the pressure of the fluid detected by the second side pressure sensor 29P becomes the specified second side target pressure.

[0077] Next, in step S204 , the controller 100 detects whether an operation stop command has been generated. If so, the controller 100 stops the operation of the temperature control fluid circulation system S1 . If not, the controller 100 returns the process to step S201 .

[0078] In the second embodiment described above, the pressure of the fluid flowing out of the temperature-controlled object T and returning to the first side flow path 13 and / or the second side flow path 23 can be maintained at a desired value. This improves the stability of the circulation state of the fluid in the first side flow path 13 and / or the second side flow path 23, thereby improving the accuracy of temperature control using the fluid.

[0079] In particular, by combining feedback control toward the target pressure based on the first side pressure sensor 19P and the second side pressure sensor 29P with feedforward control based on the pressure change rate of the fluid on the valve unit 50 side, the reliability and speed of control toward the target pressure can be improved.

[0080] Furthermore, in the second embodiment, feedforward control is performed based on information about the pressure detected by the valve unit-side pressure sensor 54. However, feedforward control may alternatively be performed based on the absolute value of the rate of change of the load applied to the stepping motor 51M, which provides the three-way valve 51 on the valve unit side. Specifically, the controller 100 may receive information related to the load of the stepping motor 51M, which serves as an actuator for applying driving force to the valve body. If the controller 100 determines, based on the received load information, that the absolute value of the rate of change of the load of the stepping motor 51M is greater than a threshold, feedforward control may be performed to change the openings of the first-side three-way valve 14 and the second-side three-way valve 24 according to an operation amount corresponding to the magnitude of the absolute value of the rate of change. In this case, feedforward control can be performed for a specific sensor through internal processing within the controller 100, which is advantageous in terms of simplicity and processing speed.

[0081] <Third embodiment>

[0082] Next, the temperature control fluid circulation system S2 according to the third embodiment will be described. Figure 5 1 is a schematic diagram of a temperature control fluid circulation system S2. Components in this embodiment that are identical to those in the first and second embodiments are denoted by the same reference numerals. In this embodiment, the structure of the valve unit 60 differs from the structure of the valve unit 50 described in the second embodiment.

[0083] The valve unit 60 includes a first slide valve 61 that switches between allowing and blocking the flow of fluid from the first temperature control fluid circulation device 10 to the temperature control target T, and a second slide valve 62 that switches between allowing and blocking the flow of fluid from the second temperature control fluid circulation device 20 to the temperature control target T. The first slide valve 61 is a proportional slide valve configured to adjust the flow rate of fluid flowing from the first temperature control fluid circulation device 10 to the temperature control target T, switching between allowing and blocking the flow of fluid from the first temperature control fluid circulation device 10 to the temperature control target T. Similarly, the second slide valve 62 is also a proportional slide valve configured to adjust the flow rate of fluid flowing from the second temperature control fluid circulation device 20 to the temperature control target T, switching between allowing and blocking the flow of fluid from the second temperature control fluid circulation device 20 to the temperature control target T.

[0084] Furthermore, a first circulation flow path 63 and a second circulation flow path 64 branch off and extend from the temperature-controlled object T. The first circulation flow path 63 is connected to the first slide valve 61, and the second circulation flow path 64 is connected to the second slide valve 62. Thus, the fluid flowing out of the temperature-controlled object T can flow into the first slide valve 61 through the first circulation flow path 63 and into the second slide valve 62 through the second circulation flow path 64.

[0085] Furthermore, the first slide valve 61 has a port for returning fluid from the first circulation flow path 63 to the first temperature control fluid circulation device 10, and is configured to adjust the flow rate of the fluid returned from the first circulation flow path 63 to the first temperature control fluid circulation device 10 in conjunction with the adjustment of the flow rate of the fluid flowing from the first temperature control fluid circulation device 10 to the temperature control target T. Similarly, the second slide valve 62 has a port for returning fluid from the second circulation flow path 64 to the second temperature control fluid circulation device 20, and is configured to adjust the flow rate of the fluid returned from the second circulation flow path 64 to the second temperature control fluid circulation device 20 in conjunction with the adjustment of the flow rate of the fluid flowing from the second temperature control fluid circulation device 20 to the temperature control target T.

[0086] In this embodiment, a first spool valve internal pressure sensor 65 is provided to detect the pressure of the fluid within the first spool valve 61, specifically, the pressure of the fluid within the port for flowing the fluid to the temperature-controlled target T. Furthermore, the controller 100 is configured to receive information regarding the pressure of the fluid within the first spool valve 61 from the first spool valve internal pressure sensor 65. If the controller 100 determines based on the received information that the absolute value of the rate of change of the pressure of the fluid within the first spool valve 61 is greater than a threshold value, the controller 100 performs feedforward control to change the openings of the first-side three-way valve 14 and the second-side three-way valve 24 according to an operation amount corresponding to the magnitude of the absolute value of the rate of change. The feedforward control follows the same process as in the second embodiment.

[0087] According to the third embodiment described above, the same operational effects as those of the second embodiment can be achieved. In the third embodiment, the first spool valve internal pressure sensor 65 detects the pressure of the fluid within the port of the first spool valve 61. However, the first spool valve internal pressure sensor 65 may also detect the pressure of the fluid after it flows out of the port of the first spool valve 61 and before it flows into the temperature-controlled object T. Furthermore, a pressure sensor may be provided on the side of the second spool valve 62.

[0088] In the present embodiment, feedforward control is performed based on information about the pressure detected by the first spool internal pressure sensor 65. However, feedforward control may alternatively be performed based on the rate of change of the load of the solenoid that drives the first spool 61. Specifically, the controller 100 may be configured to receive information related to the load of the solenoid, which serves as an actuator for applying driving force to the valve body, and, if the controller 100 determines based on the received load information that the absolute value of the rate of change of the solenoid load is greater than a threshold, perform feedforward control to change the openings of the first side three-way valve 14 and the second side three-way valve 24 according to an operation amount corresponding to the magnitude of the absolute value of the rate of change.

[0089] The above descriptions have been made on various embodiments, but the present invention is not limited to the above embodiments, and various changes can be made to the above embodiments. Such changes are also within the scope of the present invention. Figure 5 In the embodiment, the first spool valve 61 and the second spool valve 62 are separated, but the first spool valve 61 and the second spool valve 62 may have a common valve element and be integrated with each other.

Claims

1. A temperature-regulating fluid circulation device, comprising: a flow path for circulating the fluid whose temperature has been adjusted by the temperature adjustment unit through the fluid supply object; a three-way valve disposed in the flow path at a position downstream of the fluid supply destination and upstream of the temperature adjustment position of the temperature adjustment unit, with a portion between two of the three ports constituting a portion of the flow path; a bypass flow path branching from a position in the flow path downstream of the temperature adjustment position of the temperature adjustment unit and upstream of the fluid supply target, and connected to the remaining one of the three ports of the three-way valve, which is different from the two ports constituting a portion of the flow path; a pressure sensor for detecting a pressure of a fluid flowing in the flow path at a position downstream of the fluid supply destination and upstream of the three-way valve; as well as A controller, which controls the three-way valve, The controller controls the opening degree of the three-way valve so that the pressure of the fluid detected by the pressure sensor becomes a predetermined target pressure.

2. The temperature-regulating fluid circulation device according to claim 1, wherein: The temperature control fluid circulation device includes a pump for applying a driving force for circulating the fluid in the flow path. The pump is driven at a constant driving force.

3. The temperature regulating fluid circulation device according to claim 1, wherein: The fluid is a liquid, The temperature regulating fluid circulation device also has: a tank disposed in the flow path at a position downstream of the three-way valve and upstream of a temperature adjustment position of the temperature adjustment section, constituting a portion of the flow path; and A liquid level maintaining mechanism maintains a constant height of the liquid level of the liquid stored in the tank.

4. The temperature-regulating fluid circulation device according to claim 1, wherein: The controller is configured to receive information related to the temperature of the fluid supply object, and when it is determined based on the information that the absolute value of the rate of change of the temperature of the fluid supply object is greater than a threshold value, the opening of the three-way valve is changed by feedforward control according to the operating amount corresponding to the magnitude of the absolute value of the rate of change.

5. A temperature-regulating fluid circulation system, comprising: Valve unit; a first temperature-regulating fluid circulation device comprising a first side flow path, a first side three-way valve, a first side bypass flow path, and a first side pressure sensor, wherein the first side flow path circulates the fluid temperature-regulated by the first side temperature regulating portion through the valve unit, the first side three-way valve being arranged at a position downstream of the valve unit and upstream of a temperature regulating position of the first side temperature regulating portion in the first side flow path, and a portion between two of three ports constituting a portion of the first side flow path, the first side bypass flow path branches off from a position downstream of the temperature regulating position of the first side temperature regulating portion and upstream of the valve unit in the first side flow path, and is connected to the remaining one of the three ports of the first side three-way valve, which is different from the two ports constituting a portion of the first side flow path, and the first side pressure sensor detecting the pressure of the fluid flowing at a position downstream of the valve unit and upstream of the first side three-way valve in the first side flow path; and a second temperature-regulating fluid circulation device comprising a second side flow path, a second side three-way valve, a second side bypass flow path, and a second side pressure sensor, wherein the second side flow path circulates the fluid temperature-regulated by the second side temperature regulating portion through the valve unit, the second side three-way valve being arranged in the second side flow path at a position downstream of the valve unit and upstream of a temperature regulating position of the second side temperature regulating portion, and forming a part of the second side flow path by a portion between two of the three ports, the second side bypass flow path being branched from a position downstream of the temperature regulating position of the second side temperature regulating portion and upstream of the valve unit in the second side flow path, and being connected to the remaining one of the three ports of the second side three-way valve, which is different from the two ports constituting a part of the second side flow path, the second side pressure sensor detecting the pressure of the fluid flowing in the second side flow path at a position downstream of the valve unit and upstream of the second side three-way valve; and A controller controls the first side three-way valve and the second side three-way valve, The valve unit transports the fluid received from the first temperature control fluid circulation device, the fluid received from the second temperature control fluid circulation device, or a mixture of the fluid received from the first temperature control fluid circulation device and the fluid received from the second temperature control fluid circulation device to the temperature control object, and returns the fluid passing through the temperature control object to the first side flow path and / or the second side flow path. The controller controls the opening of the three-way valve on the first side so that the pressure of the fluid detected by the first side pressure sensor becomes the specified first side target pressure, and controls the opening of the three-way valve on the second side so that the pressure of the fluid detected by the second side pressure sensor becomes the specified second side target pressure.

6. The temperature-regulating fluid circulation system according to claim 5, wherein: The fluid circulating in the first temperature control fluid circulation device and the fluid circulating in the second temperature control fluid circulation device are the same liquid. The first temperature control fluid circulation device includes a first side tank, which is arranged in the first side flow path at a position downstream of the first side three-way valve and upstream of the temperature control position of the first side temperature control unit, and constitutes a part of the first side flow path. The second temperature control fluid circulation device includes a second side tank, which is arranged in the second side flow path at a position downstream of the second side three-way valve and upstream of the temperature control position of the second side temperature control unit, and constitutes a part of the second side flow path. The liquid storage position of the first side tank and the liquid storage position of the second side tank are connected via a piping member.

7. The temperature-controlled fluid circulation system according to claim 5, wherein: The valve unit includes a valve unit side three-way valve, and the valve unit side three-way valve includes a first receiving port, a second receiving port, and a supply port. The valve unit-side three-way valve can change the mixing ratio of the fluid received from the first temperature regulating fluid circulation device at the first receiving port and the fluid received from the second temperature regulating fluid circulation device at the second receiving port according to the position of the valve body, and the fluid flows out from the supply port. The controller is configured to receive information related to the pressure of the fluid in the three-way valve on the valve unit side, and when it is determined based on the information that the absolute value of the rate of change of the pressure of the fluid in the three-way valve on the valve unit side is greater than a threshold value, the opening of the three-way valve on the first side and the opening of the three-way valve on the second side are changed through feedforward control according to the operating amount corresponding to the magnitude of the absolute value of the rate of change.

8. The temperature-regulating fluid circulation system according to claim 5 or 6, wherein: The valve unit includes a valve unit side three-way valve, and the valve unit side three-way valve includes a first receiving port, a second receiving port, and a supply port. The valve unit-side three-way valve can change the mixing ratio of the fluid received from the first temperature regulating fluid circulation device at the first receiving port and the fluid received from the second temperature regulating fluid circulation device at the second receiving port according to the position of the valve body, and the fluid flows out from the supply port. The controller is configured to receive information related to the load of the actuator that applies driving force to the valve body, and when it is determined based on the information that the absolute value of the rate of change of the load of the actuator is greater than a threshold value, the controller is configured to change the opening of the first side three-way valve and the opening of the second side three-way valve according to the operation amount corresponding to the magnitude of the absolute value of the rate of change through feedforward control.

9. The temperature-regulating fluid circulation system according to claim 5 or 6, wherein: The valve unit includes a slide valve that can change the mixing ratio of the fluid received from the first temperature control fluid circulation device and the fluid received from the second temperature control fluid circulation device according to the position of the valve element, and flow the fluid toward the temperature control target side. The controller is configured to receive information related to the pressure of the fluid in the slide valve or the fluid flowing from the slide valve into the temperature control object, and when it is determined based on the information that the absolute value of the rate of change of the pressure of the fluid in the slide valve is greater than a threshold value, change the opening of the first-side three-way valve and the opening of the second-side three-way valve according to an operation amount corresponding to the magnitude of the absolute value of the rate of change through feedforward control.

10. The temperature-regulating fluid circulation system according to claim 5 or 6, wherein: The valve unit includes a slide valve that can change the mixing ratio of the fluid received from the first temperature control fluid circulation device and the fluid received from the second temperature control fluid circulation device according to the position of the valve element, and flow the fluid toward the temperature control target side. The controller is configured to receive information related to the load of the actuator that applies driving force to the valve core, and when it is determined based on the information that the absolute value of the rate of change of the load of the actuator is greater than a threshold value, the controller is configured to change the opening of the first side three-way valve and the opening of the second side three-way valve according to the operating amount corresponding to the magnitude of the absolute value of the rate of change through feedforward control.

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