Supercooled water supply system

Abstract

To provide a supercooled water supply system that can supply supercooled water.SOLUTION: In accordance with the present invention, a supercooled water supply system, which is a supercooled water supply system for supplying supercooled water and includes cold water supply means for supplying cold water at a preset temperature, a refrigerator for cooling the refrigerant, and a heat exchanger, and, in the heat exchanger, heat is exchanged between the cold water and the refrigerant to further cool the cold water to generate and supply supercooled water, is provided.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a supercooled water supply system for supplying supercooled water.

Background Art

[0002] Conventionally, there is a cooling water supply system for supplying cold water for cooling foods and the like. For example, Patent Document 1 discloses an ice storage type cold water device that generates ice water in an ice storage tank by circulating a refrigerant between a heat exchanger and a refrigerator and circulating cold water between the heat exchanger and the ice storage tank, and supplies cooling water from the ice storage tank to a cooling tank as needed.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] By the way, when cooling an object to be cooled in a cooling tank for cooling the object to be cooled, usually, the set temperature of the cooling tank is determined according to the heat quantity of the object to be cooled and the cooling possible time, and cooling water is continuously supplied so that the set temperature is maintained. And in such a case, the lower the water temperature of the cooling water to be supplied, the less amount is required. [[ID=3​​​​​​​​​​

[0007] According to the present invention, a supercooled water supply system is provided, comprising a chilled water supply means for supplying chilled water at a preset temperature, a refrigerator for cooling a refrigerant, and a heat exchanger, wherein the chilled water is further cooled by heat exchange between the chilled water and the refrigerant in the heat exchanger, thereby generating and supplying supercooled water.

[0008] According to the present invention, it is possible to generate and supply supercooled water by further cooling the chilled water supplied by the chilled water supply means with a heat exchanger. Furthermore, by setting the chilled water supplied by the chilled water supply means to a preset temperature, freezing of the chilled water inside the heat exchanger can be avoided. In addition, if the temperature on the upstream side of the heat exchanger is constant, it is possible to estimate the temperature of the water on the downstream side of the heat exchanger. Therefore, it is possible to omit the installation of a temperature sensor on the downstream side of the heat exchanger and prevent the generated supercooled water from coming into contact with the temperature sensor and eliminating the supercooled state.

[0009] The following are examples of various embodiments of the present invention. The embodiments shown below can be combined with each other.

[0010] Preferably, the chilled water supply means comprises a water supply means and a chiller, wherein the water supply means is configured to supply room temperature water, the chiller is configured to supply chiller water, and the chilled water supply means mixes the chiller water and the room temperature water and supplies the chilled water to the heat exchanger.

[0011] Preferably, the system includes a chilled water supply means and a control means for controlling the chiller, the chilled water supply means comprising a water pump and a temperature sensor, the water pump being positioned downstream of the mixing position where the chiller water and the ambient water are mixed and configured to supply water at a constant flow rate, the temperature sensor being configured to detect the temperature of the chilled water, the water supply means comprising a water supply line to which the ambient water is supplied and a water supply flow rate adjustment valve positioned in the water supply line and capable of adjusting the flow rate, and the control means providing feedback control to the water supply flow rate adjustment valve so that the temperature of the chilled water detected by the temperature sensor becomes the preset temperature.

[0012] Preferably, the system includes at least one of a first pressure sensor located downstream of the water supply pump and configured to detect the pressure of the chilled water, and a second pressure sensor located downstream of the heat exchanger in a refrigerant circulation line that circulates the refrigerant between the chiller and the heat exchanger and configured to detect the pressure of the refrigerant, wherein the control means detects freezing of the chilled water in the heat exchanger based on the chilled water pressure detected by the first pressure sensor and / or the refrigerant pressure detected by the second pressure sensor.

[0013] Preferably, the system is configured to supply the supercooled water to a cooling tank and includes a supercooled water supply line connecting the heat exchanger and the cooling tank, the supercooled water supply line being made of bent piping.

[0014] Preferably, the system is configured to supply the supercooled water to a cooling tank, and the heat exchanger is positioned adjacent to the cooling tank.

[0015] Preferably, the system is configured to supply the supercooled water to a cooling tank, and includes a bypass line that bypasses the heat exchanger, and is configured to supply the chilled water supplied by the chilled water supply means to the cooling tank via the bypass line. [Brief explanation of the drawing]

[0016] [Figure 1] This is a schematic diagram showing a supercooled water supply system 1 according to one embodiment of the present invention. [Modes for carrying out the invention]

[0017] Embodiments of the present invention will be described below. The various features shown in the embodiments below can be combined with each other. Furthermore, each feature constitutes an independent invention.

[0018] 1. Configuration of the supercooled water supply system 1 First, the configuration of the supercooled water supply system 1 according to one embodiment of the present invention will be described. The supercooled water supply system 1 is used to supply chilled water to a cooling tank 100 for the purpose of cooling a product to be processed, such as food. As shown in Figure 1, the supercooled water supply system 1 of this embodiment comprises a chilled water supply means 2, a refrigerator 3, and a heat exchanger 4. The supercooled water supply system 1 also comprises lines connecting these components: a chilled water line 5 connecting the chilled water supply means 2 and the heat exchanger 4; a bypass line 6 bypassing the heat exchanger 4 and connecting the chilled water supply means 2 and the cooling tank 100; a refrigerant circulation line 7 connecting the refrigerator 3 and the heat exchanger 4; a refrigerant bypass line 8 connecting the compressor 30 of the refrigerator 3 (described later) and the heat exchanger 4; and a supercooled water supply line 9 connecting the heat exchanger 4 and the cooling tank 100. Furthermore, the supercooled water supply system 1 includes control means 10 for controlling the operation of each element. The following describes each component in detail.

[0019] The chilled water supply means 2 supplies chilled water at a preset temperature and comprises a water supply means 20, a chiller 21, a water pump 22, and a temperature sensor 23.

[0020] The water supply means 20 includes a water supply line 20a connecting a water supply source (not shown) for supplying normal temperature water and a water supply pump 22, a water supply flow rate adjustment valve 20b disposed in the water supply line 20a and capable of adjusting the flow rate, and a water supply valve 20c disposed downstream of the water supply flow rate adjustment valve 20b. An electric valve with high responsiveness is used for the water supply flow rate adjustment valve 20b. The water supply means 20 is configured to supply normal temperature water (for example, water at about 18°C) to the water supply pump 22. Note that the normal temperature water is, for example, water supplied from a water supply system, but it is not particularly limited as long as it is water that can be used for cooling objects to be processed such as food.

[0021] The chiller 21 cools the normal temperature water supplied from a water supply line (not shown) and generates chiller water at around 0°C (usually about 0.5°C to 1.5°C). The chiller 21 in this embodiment is a water chiller with a flowing water specification that does not circulate the generated chiller water, and the generated chiller water is sent to the water supply pump 22 via the chiller water line 21a. Here, a chiller water valve 21b is provided in the chiller water line 21a.

[0022] Specifically, the chiller 21 includes a compressor, a condenser, an expansion valve, and an evaporator (not shown), executes a refrigeration cycle of compressing, condensing, expanding, and evaporating a refrigerant, and cools the normal temperature water by performing heat exchange with the refrigerant in the evaporator (heat exchanger). Since the configuration of the chiller 21 is conventionally known, a detailed description thereof is omitted.

[0023] The water supply pump 22 is disposed downstream of the position where the water supply line 20a and the chiller water line 21a merge, that is, the mixing position 24 where the normal temperature water and the chiller water are mixed. The water supply pump 22 is configured to uniformly mix the normal temperature water and the chiller water and send the mixed water as cold water with a constant flow rate. In the water supply means 20, the line downstream of the mixing position 24 is referred to as the mixed water line 25.

[0024] The temperature sensor 23 is arranged on the downstream side of the water pump 22 of the mixed water line 25 and is configured to detect the water temperature of the chilled water, which is the mixed water of the normal temperature water and the chiller water. By arranging it on the downstream side of the water pump 22, the water is mixed by the water pump 22 and the temperature becomes uniform, and the temperature of the chilled water with less temperature unevenness can be detected. In addition, since the water temperature considering the heat input from the water pump 22 can be detected, it is possible to detect a temperature close to the temperature actually entering the heat exchanger 4.

[0025] The chilled water supplied by the chilled water supply means 2 configured as described above is sent to the heat exchanger 4 through the chilled water line 5 connected to the mixed water line 25 by driving the water pump 22. Here, a filter 50, a first pressure sensor 51, and a chilled water valve 52 are provided in the chilled water line 5.

[0026] The filter 50 is provided to prevent the chilled water from freezing in the heat exchanger 4 and is configured to remove foreign substances that become the nuclei of freezing.

[0027] The first pressure sensor 51 is arranged on the downstream side of the filter 50 and detects the pressure of the chilled water entering the heat exchanger 4. When the chilled water freezes in the heat exchanger 4, the pressure of the chilled water rises on the upstream side of the heat exchanger 4. Therefore, by detecting the pressure rise with the first pressure sensor 51, freezing can be detected. The first pressure sensor 51 can be composed of, for example, two pressure switches, a freezing switch for detecting that the chilled water has frozen and a thawing switch for detecting that the chilled water has thawed. Also, by arranging the first pressure sensor 51 on the downstream side of the filter 50, it is possible to suppress false detection of freezing due to clogging of the filter 50.

[0028] The chilled water valve 52 switches the flow and the stop of the chilled water flowing through the chilled water line 5, that is, the chilled water entering the heat exchanger 4. As the chilled water valve 52, for example, an electric valve is used.

[0029] Furthermore, the supercooled water supply system 1 of this embodiment also includes a bypass line 6 that branches off from the chilled water line 5, bypasses the heat exchanger 4, and directly supplies chilled water supplied by the chilled water supply means 2 to the cooling tank 100. A bypass valve 60 is provided in the bypass line 6. For example, an electric valve is used as the bypass valve 60.

[0030] The refrigerator 3 comprises a compressor 30 and a condenser 31, and cools the refrigerant. The refrigerator 3 is connected to the heat exchanger 4 by a refrigerant circulation line 7, which is equipped with a circulation valve 70, an expansion valve 71, a second pressure sensor 72, and a refrigerant temperature sensor 73. The refrigerant circulation line 7 is connected to circulate the refrigerant in the order of compressor 30, condenser 31, expansion valve 71, and heat exchanger 4 (evaporator), and the refrigeration cycle of compression, condensation, expansion, and evaporation of the refrigerant is executed as the refrigerant circulates through the refrigerant circulation line 7. It is preferable to use a solenoid valve for the circulation valve 70.

[0031] The compressor 30 adiabatically compresses the low-temperature, low-pressure refrigerant gas into a high-temperature, high-pressure gas. The refrigerant, now in a high-temperature, high-pressure gas state in the compressor 30, is preferably sent to the condenser 31 via an oil separator (not shown). For example, a scroll compressor is used for the compressor 30.

[0032] The condenser 31 condenses the high-temperature, high-pressure gas from the compressor 30 into a low-temperature, high-pressure refrigerant liquid. In this embodiment, the condenser 31 is an air-cooled heat exchanger equipped with a fan 31a. However, a water-cooled condenser 31 can also be used. The refrigerant, now in the low-temperature, high-pressure refrigerant liquid state in the condenser 31, is sent to the expansion valve 71 through the refrigerant circulation line 7.

[0033] The expansion valve 71 reduces the pressure of the refrigerant, which has become a low-temperature, high-pressure liquid refrigerant in the condenser 31, to a low-temperature, low-pressure liquid refrigerant. The expansion valve 71 is a valve whose opening degree can be controlled, and the opening degree is controlled by the control means 10. By adjusting the opening degree of the expansion valve 71 with the control means 10, the degree of pressure reduction can be adjusted. The refrigerant, which has become a low-temperature, low-pressure liquid refrigerant in the expansion valve 71, is sent to the heat exchanger 4, which acts as an evaporator. The expansion valve 71 may be an electronic expansion valve or a mechanical expansion valve.

[0034] Furthermore, the supercooled water supply system 1 of this embodiment also includes a refrigerant bypass line 8 that bypasses the condenser 31 and expansion valve 71 to connect the compressor 30 and heat exchanger 4 of the refrigerator 3, and a refrigerant bypass valve 80 is installed in the refrigerant bypass line 8. A solenoid valve is also used for the refrigerant bypass valve 80.

[0035] The heat exchanger 4 functions as an evaporator in the refrigeration cycle. The heat exchanger 4 is equipped with a refrigerant flow path and a chilled water flow path, and indirectly exchanges heat between the refrigerant and chilled water without mixing them. In the heat exchanger 4, the refrigerant liquid, which has become low temperature and low pressure after passing through the expansion valve 71, absorbs heat from the chilled water and evaporates while maintaining a constant pressure, thereby removing heat from the chilled water and cooling the chilled water. For example, a double-tube heat exchanger is used for the heat exchanger 4. By adjusting the opening of the expansion valve 71, the refrigerant is ensured to evaporate completely in the heat exchanger 4.

[0036] Furthermore, it is preferable to set the operating conditions of the refrigerator 3 so that the temperature at which the refrigerant evaporates in the heat exchanger 4 (evaporation temperature) is -5°C or higher. If the evaporation temperature is low, there is a higher possibility that the chilled water will freeze in the heat exchanger 4. However, if the evaporation temperature is less than 0°C and close to 0°C, it is possible to cool the chilled water in the heat exchanger 4 while suppressing the freezing of the chilled water.

[0037] In the heat exchanger 4, the refrigerant that has absorbed heat from the chilled water and evaporated is sent to the compressor 30 in the form of a low-temperature, low-pressure gas through the refrigerant circulation line 7.

[0038] A second pressure sensor 72 and a refrigerant temperature sensor 73 are positioned downstream of the heat exchanger 4 in the refrigerant circulation line 7, that is, between the heat exchanger 4 and the compressor 30. The second pressure sensor 72 is configured to detect the pressure of the refrigerant in the heat exchanger 4. The refrigerant temperature sensor 73 is configured to detect the temperature of the refrigerant evaporated by the heat exchanger 4 that is drawn into the compressor 30.

[0039] Furthermore, the supercooled water supply system 1 of this embodiment includes a supercooled water supply line 9 that connects the heat exchanger 4 and the cooling tank 100, and the chilled water flow path of the heat exchanger 4 is connected to the supercooled water supply line 9 that connects the heat exchanger 4 and the cooling tank 100. The chilled water that has passed through the heat exchanger 4 is cooled by heat exchange with the refrigerant and becomes supercooled water that flows through the supercooled water supply line 9.

[0040] In this embodiment, the supercooled water supply line 9 is constructed using bent piping and has no joints. This configuration prevents the supercooled water flowing through the supercooled water supply line 9 from freezing due to contact with steps or other uneven surfaces caused by joints. Furthermore, the supercooled water supply system 1 of this embodiment is configured to minimize the piping distance of the supercooled water supply line 9. Specifically, in the supercooled water supply system 1 of this embodiment, the heat exchanger 4 is positioned adjacent to the cooling tank 100. Here, "adjacent position" can be defined, for example, as a position where the piping distance of the supercooled water supply line 9 is within 10m. Alternatively, "adjacent position" can be defined as a positional relationship where the heat exchanger 4 and the cooling tank 100 are installed on the same floor. By positioning the heat exchanger 4 and the cooling tank 100 adjacent to each other and shortening the piping distance of the supercooled water supply line 9, freezing of the supercooled water in the supercooled water supply line 9 can be suppressed.

[0041] Furthermore, a three-way valve 90 is provided in the supercooled water supply line 9, and a drain line 91 is connected to the three-way valve 90 to drain the water from the heat exchanger 4 without allowing it to flow into the cooling tank 100. It is preferable to use a three-way valve 90 that has as few steps as possible.

[0042] The control means 10 controls each of the above-described components based on detection signals from the temperature sensor 23, the first pressure sensor 51, and the second pressure sensor 72, as well as elapsed time. Specifically, the control means 10 controls the water supply flow rate adjustment valve 20b, water supply valve 20c, chiller 21, chiller water valve 21b, and water supply pump 22 of the chilled water supply means 2, the chiller 3 (compressor 30 and condenser 31), the circulation valve 70, the expansion valve 71, the chilled water valve 52, the bypass valve 60, the refrigerant bypass valve 80, and the three-way valve 90. The control means 10 is also connected to the temperature sensor 23, the first pressure sensor 51, the second pressure sensor 72, the refrigerant temperature sensor 73, etc. As will be described later, the control means 10 controls the generation and supply of supercooled water according to a predetermined procedure (program).

[0043] The control means 10 described above can be specifically configured as an information processing device equipped with a CPU, memory (e.g., flash memory), an input unit, and an output unit. The processing performed by each of the above-mentioned components of the control means 10 configured by the information processing device is carried out by the CPU reading and executing a program stored in memory. Examples of information processing devices include personal computers, PLCs (programmable logic controllers), or microcontrollers. However, some functions of the control means 10 may be configured to be executed on a cloud connected by any communication means.

[0044] 2. Operation of the supercooled water supply system 1 Next, the operation of the supercooled water supply system 1 of this embodiment will be described. In this embodiment, the supercooled water supply system 1, under the control of the control means 10, first generates chilled water at a preset temperature using the chilled water supply means 2, and supplies the generated chilled water to the heat exchanger 4. Then, the chilled water is further cooled by heat exchange with the refrigerant cooled by the refrigerator 3, generating supercooled water which is supplied to the cooling tank 100. Each of these operations will be described in detail below.

[0045] <Cold water generation operation by cold water supply means 2> To generate chilled water at a preset temperature using the chilled water supply means 2, the control means 10 first opens the water supply flow rate adjustment valve 20b and the water supply valve 20c of the water supply line 20a, and drives the water supply pump 22. At the same time, the control means 10 starts the operation of the chiller 21 and opens the chiller water valve 21b of the chiller water line 21a. As a result, the ambient temperature water from the water supply line 20a and the chiller water from the chiller water line 21a are mixed, and the chilled mixed water flows through the mixed water line 25. Here, the flow rate of chilled water flowing through the mixed water line 25, that is, the flow rate of chilled water supplied to the heat exchanger 4, is maintained at a constant flow rate according to the capacity of the water supply pump 22, because the water supply pump 22 is located downstream of the mixing position 24.

[0046] Next, the control means 10 obtains the temperature of the chilled water flowing through the mixed water line 25 from the temperature sensor 23 and performs feedback control (PID control) of the opening degree of the water supply flow rate control valve 20b so that the chilled water temperature is maintained at a preset temperature (a constant temperature). Specifically, if the chilled water temperature detected by the temperature sensor 23 is higher than the set temperature (for example, 3°C), the control means 10 reduces the opening degree of the water supply flow rate control valve 20b. This reduces the proportion of room temperature water in the mixed water and increases the proportion of chilled water, thus lowering the temperature of the mixed water. On the other hand, if the chilled water temperature detected by the temperature sensor 23 is lower than the set temperature, the control means 10 increases the opening degree of the water supply flow rate control valve 20b. This increases the proportion of room temperature water in the mixed water and decreases the proportion of chilled water, thus raising the temperature of the mixed water.

[0047] In this embodiment, the chilled water supply means 2 generates mixed water at a preset temperature through the control means 10 and supplies the mixed water at a constant flow rate as chilled water via the water pump 22. It is preferable that the set temperature of the chilled water to be feedback controlled varies according to the cooling capacity of the refrigerator 3 (which depends on the ambient temperature, etc.). Specifically, for example, it is preferable to lower the set temperature for feedback control when the ambient temperature is high and the cooling capacity of the refrigerator 3 is low, and to raise the set temperature when the ambient temperature is low and the cooling capacity of the refrigerator 3 is high.

[0048] <Cooling operation by refrigerator 3> To cool the refrigerant with the chiller 3 and the chilled water with the heat exchanger 4, the refrigerant is circulated between the chiller 3 and the heat exchanger 4 via the refrigerant circulation line 7. Specifically, the control means 10 drives the chiller 3 (compressor 30), opens the circulation valve 70, and closes the refrigerant bypass valve 80, thereby circulating the refrigerant in the order of compressor 30, condenser 31, expansion valve 71, and heat exchanger 4 (evaporator), executing the refrigeration cycle of compression, condensation, expansion, and evaporation of the refrigerant. As the refrigerant flows through the heat exchanger 4, heat exchange occurs with the chilled water also flowing through the heat exchanger 4, thereby cooling the chilled water.

[0049] In this embodiment, the control means 10 controls the chilled water supply means 2 so that the chilled water flowing into the heat exchanger 4 is maintained at a preset temperature, as described above. The control means 10 also calculates the suction superheat of the refrigerant drawn into the compressor 30 (the temperature rise from the refrigerant's evaporation temperature) from the refrigerant evaporation temperature (saturation temperature) calculated from the refrigerant pressure detected by the second pressure sensor 72 and the refrigerant temperature detected by the refrigerant temperature sensor 73, and adjusts the opening of the expansion valve 71 so that the suction superheat becomes a target temperature (for example, 5K to 15K) corresponding to the preset chilled water temperature. As a result, a certain amount of heat is removed from the chilled water flowing into the heat exchanger 4, and the chilled water becomes supercooled water at a constant temperature, which flows through the supercooled water supply line 9 and is supplied to the cooling tank 100. It is preferable that the temperature of the supplied supercooled water be around -1.0℃ to -0.6℃. Within this temperature range, freezing of the supercooled water in the heat exchanger 4 and the like can be effectively suppressed.

[0050] Furthermore, in the supercooled water supply system 1 of this embodiment, a first pressure sensor 51 provided in the chilled water line 5 to detect the pressure of the chilled water, and a second pressure sensor 72 provided in the refrigerant circulation line 7 to detect the pressure of the refrigerant, are used to detect freezing of the chilled water in the heat exchanger 4 for any reason.

[0051] Specifically, the control means 10 detects freezing when the chilled water pressure detected by the first pressure sensor 51 exceeds the chilled water upper limit pressure, considering that when chilled water freezes in the heat exchanger 4, the chilled water pressure in the chilled water line 5 increases. Furthermore, the control means 10 also detects freezing when the chilled water pressure detected by the second pressure sensor 72 falls below the chilled water lower limit pressure, considering that when chilled water freezes in the heat exchanger 4, the amount of heat exchanged between the chilled water and the refrigerant decreases and the refrigerant pressure does not increase more than normal.

[0052] It is preferable that the upper limit pressure of the chilled water and the lower limit pressure of the refrigerant be confirmed in advance for each set temperature of chilled water supplied by the chilled water supply means 2 and stored in the memory of the control means 10. Alternatively, the control means 10 may detect chilled water freezing based on only one of the chilled water pressures detected by the first pressure sensor 51 and the refrigerant pressures detected by the second pressure sensor 72. When chilled water freezing is detected in the heat exchanger 4, the control means 10 performs the defrost operation described below.

[0053] <Defrost operation> The defrost operation (thawing operation) is an operation performed when freezing of the chilled water in the heat exchanger 4 is detected. This operation involves supplying hot gas to the heat exchanger 4 and using the heat of the hot gas to thaw the frozen water. The defrost operation will be explained in detail below.

[0054] When performing a defrost operation, the control means 10 closes the circulation valve 70 provided in the refrigerant circulation line 7 and opens the refrigerant bypass valve 80 provided in the refrigerant bypass line 8. As a result, the refrigerant (hot gas), which has become a high-temperature, high-pressure gas by the compressor 30 of the chiller 3, circulates by bypassing the condenser 31 and the expansion valve 71. This allows the hot gas to be supplied directly to the heat exchanger 4, and the chilled water frozen in the heat exchanger 4 is thawed. At this time, the control means 10 controls the three-way valve 90 of the supercooled water supply line 9 so that the water produced by thawing in the heat exchanger 4 is drained from the drain line 91 instead of flowing into the cooling tank 100. This prevents the water heated by the hot gas (thawed water) from being supplied to the cooling tank 100.

[0055] Furthermore, while the chiller 3 is performing a defrosting operation, the control means 10 closes the water supply valve 20c provided in the water supply line 20a of the chilled water supply means 2 and opens the chiller water valve 21b provided in the chiller water line 21a, thereby controlling the chilled water supply means 2 to supply only chiller water. At the same time, the control means 10 closes the chilled water valve 52 of the chilled water line 5 and opens the bypass valve 60 of the bypass line 6, so that chiller water is supplied directly to the cooling tank 100 without passing through the heat exchanger 4. This makes it possible to continue supplying chilled water (chiller water) with a water temperature close to 0°C to the cooling tank 100 even during defrosting.

[0056] Then, the control means 10 terminates the defrosting operation if the chilled water pressure detected by the first pressure sensor 51 becomes the normal chilled water pressure and / or the refrigerant pressure detected by the second pressure sensor 72 becomes the normal refrigerant pressure, indicating that the chilled water has thawed. To terminate the defrosting operation, the control means 10 opens the circulation valve 70 of the refrigerant circulation line 7 and closes the refrigerant bypass valve 80 of the refrigerant bypass line 8. The control means 10 also opens the water supply valve 20c of the water supply line 20a and the chilled water valve 52 of the chilled water line 5 of the chilled water supply means 2, and closes the bypass valve 60 of the bypass line 6. As a result, the supercooled water supply system 1 resumes supplying supercooled water.

[0057] 3. Effects As described above, the supercooled water supply system 1 of this embodiment is capable of generating and supplying supercooled water by having the chilled water supply means 2 supply chilled water at a preset temperature, and further cooling the chilled water through heat exchange with the refrigerant cooled by the refrigerator 3 in the heat exchanger 4. Furthermore, if the temperature on the upstream side of the heat exchanger 4 (the temperature of the chilled water flowing in the chilled water line 5) is constant, it is possible to estimate the temperature of the cooled water on the downstream side of the heat exchanger 4. Therefore, the installation of a temperature sensor on the downstream side of the heat exchanger 4 can be omitted, and it is possible to prevent the generated supercooled water from coming into contact with the temperature sensor and eliminating the supercooled state.

[0058] In addition, the chilled water supply means 2 mixes ambient temperature water from the water supply means 20 with chilled water from the chiller 21, and adjusts the ratio of chilled water to ambient temperature water supplied by feedback control of the water supply flow rate adjustment valve 20b based on the temperature of the mixed water detected by the temperature sensor 23, thereby enabling the production of chilled water at a preset constant temperature with good responsiveness.

[0059] In addition, the chiller 21 itself can supply chilled water at a nearly constant temperature in the chilled water supply means 2. However, the temperature of the water supplied by the chiller 21 fluctuates due to room temperature (outside temperature), etc., and its responsiveness is poor. Therefore, if chiller water itself is supplied to the heat exchanger 4, there is a risk of freezing. In this regard, in the supercooled water supply system 1 of this embodiment, the chilled water supply means 2 mixes chiller water with room temperature water and adjusts the water temperature by the opening of the highly responsive water supply flow rate control valve 20b. This ensures that chilled water at a constant temperature is reliably supplied to the heat exchanger 4, and makes it possible to suppress the freezing of chilled water in the heat exchanger 4.

[0060] 4. Variations Furthermore, the present invention can also be implemented in the following embodiments.

[0061] In the above embodiment, the temperature sensor 23 in the chilled water supply means 2 was located downstream of the water pump 22 in the mixed water line 25. However, the temperature sensor 23 can also be located upstream of the water pump 22. By placing the temperature sensor 23 upstream of the water pump 22, which does not have a high flow rate or velocity, it is possible to suppress failure of the temperature sensor 23 due to vibration. However, when the temperature sensor 23 is placed upstream of the water pump 22, the temperature of the mixed water to be detected is less likely to be uniform, so in this case, it is preferable to increase the diameter of the upstream piping of the water pump 22 where the temperature sensor is placed.

[0062] In the above embodiment, the chilled water supply means 2 comprises a water supply means 20 and a chiller 21, and is configured to produce chilled water by mixing room temperature water and chiller water. However, as long as it is possible to supply chilled water at a constant temperature, the chilled water supply means 2 may consist only of the chiller 21, or it may be configured to supply chilled water by other means.

[0063] In the above embodiment, the supercooled water supply system 1 was configured to supply supercooled water to the cooling tank 100. However, the supercooled water supply system 1 according to the present invention can supply supercooled water to any location or object other than the cooling tank 100. [Explanation of symbols]

[0064] 1: Supercooled water supply system 2: Cold water supply means 3: Refrigeration unit 4: Heat exchanger 5: Cold water line 6: Bypass Line 7: Refrigerant circulation line 8: Refrigerant bypass line 9: Supercooled water supply line 10: Control means 20: Water supply means 20a: Water supply line 20b: Water supply flow control valve 20c: Water supply valve 21: Chiller 21a: Chiller water line 21b: Chiller water valve 22: Water pump 23: Temperature sensor 24:Mixing position 25: Mixing water line 30: Compressor 31: Condenser 31a: Fan 50: Filter 51: First pressure sensor 52: Cold water valve 60: Bypass valve 70: Circulation valve 71: Expansion valve 72: Second pressure sensor 73: Refrigerant temperature sensor 80: Refrigerant bypass valve 90: Three-way valve 91: Drainage line 100: Cooling tank

Claims

1. A supercooled water supply system for supplying supercooled water, It comprises a chilled water supply means that supplies chilled water at a preset temperature, a refrigerator that cools the refrigerant, and a heat exchanger. The chilled water supply means is equipped with a water pump capable of supplying water at a constant flow rate, and is configured to supply the chilled water at a constant flow rate to the heat exchanger using the water pump. The chilled water supply means further comprises a water supply means and a chiller. The water supply means is configured to supply room temperature water, The chiller is configured to be able to supply chiller water, The water supply pump is positioned downstream of the mixing point where the chiller water and the room temperature water are mixed. The chilled water supply means mixes the chiller water and the room temperature water and supplies the chilled water at a constant flow rate to the heat exchanger using the water pump. A supercooled water supply system that further cools the chilled water by exchanging heat between the chilled water and the refrigerant flowing through the heat exchanger, thereby generating and supplying supercooled water.

2. A supercooled water supply system according to Claim 1, The system includes the aforementioned chilled water supply means and the control means for controlling the chiller, The cold water supply means further includes a temperature sensor, The temperature sensor is configured to detect the water temperature of the cold water, The water supply means comprises a water supply line through which the room temperature water is supplied, and a water supply flow rate adjustment valve located in the water supply line and capable of adjusting the flow rate. The control means provides a supercooled water supply system that provides feedback control to the water supply flow rate adjustment valve so that the water temperature of the chilled water detected by the temperature sensor reaches the preset temperature.

3. A supercooled water supply system according to Claim 2, The system comprises at least one of the following: a first pressure sensor located downstream of the water supply pump and configured to detect the pressure of the chilled water; and a second pressure sensor located downstream of the heat exchanger in a refrigerant circulation line that circulates the refrigerant between the chiller and the heat exchanger and configured to detect the pressure of the refrigerant. The control means is a supercooled water supply system that detects freezing of the chilled water in the heat exchanger based on the pressure of the chilled water detected by the first pressure sensor and / or the pressure of the refrigerant detected by the second pressure sensor.

4. A supercooled water supply system according to any one of claims 1 to 3, The system is configured to supply the supercooled water to the cooling tank, The heat exchanger and the cooling tank are connected by a supercooling water supply line, The supercooled water supply line is a supercooled water supply system consisting of bent piping.

5. A supercooled water supply system according to any one of claims 1 to 4, The system is configured to supply the supercooled water to the cooling tank, A supercooled water supply system in which the heat exchanger is positioned adjacent to the cooling tank.

6. A supercooled water supply system according to any one of claims 1 to 5, The system is configured to supply the supercooled water to the cooling tank, The aforementioned heat exchanger is provided with a bypass line, A supercooled water supply system configured to supply the chilled water supplied by the chilled water supply means to the cooling tank via the bypass line.

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