JP2002107017A - Method for controlling ice storage type chilled water device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for controlling an ice storage type chilled water device capable of efficiently supplying chilled water and icemaking, without causing freezing of a heat exchanger under the control of a chilled water producing operation of the ice storage type chilled water device. SOLUTION: The method for controlling the ice storage type chilled water, device having a refrigerating unit, a heat exchanger for supercooling water and an ice storage tank, comprises the step of controlling water to be cooled at an outlet of the exchanger for the supercoooling water so as not to search supercooling, based on a detected value of a flow rate detecting means provided at a chilled water output line of the tank.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the technical field of supercooled water, and more particularly to a method for controlling an ice storage type chilled water device.

[0002]

2. Description of the Related Art Conventionally, there is an ice storage type chiller for supplying chilled water to an air conditioner or a food cooling device. As shown in FIG. 2, the ice storage type chilled water device communicates between an ice storage tank 31 and a supercooled water heat exchanger 32 (hereinafter, referred to as a “heat exchanger 32”) by a circulation line 33. Together with the heat exchanger 32
And the refrigerator 34 are connected by a refrigerant circulation line 35. The ice storage type chilled water device stores ice in the ice storage tank 31 by using late-night electric power at a low electricity rate, and responds to a load demand during operation of the food cooling device or the like, so that the ice is stored above the ice storage tank 31. In addition to supplying the deicing water from, the cold water is taken out from the lower part.

When a predetermined amount of ice is stored in the ice storage tank 31 and cold water is taken out in response to a load request, the ice storage type chiller is started. However, when the amount of cold water required on the load side is small, the water level in the ice storage tank 31 does not drop so much, and the supercooled water flowing from the outlet of the heat exchanger 32 hits the ice storage surface. The supercooling is released, and a part of the ice rises as ice bamboo shoots and reaches the outlet of the heat exchanger 32 to freeze. If the load requires a large amount of cold water, the ice storage tank 31
The water level in the inside gradually decreases, and when the water level reaches the lower limit, the supply of cold water to the load side is stopped.

[0004]

SUMMARY OF THE INVENTION In view of the above-mentioned problems, the present invention provides a method for controlling the supply of cold water and making ice efficiently without freezing the heat exchanger in the control of the ice storage type chilled water device during the cold water removal operation. It is an object of the present invention to provide a method of controlling an ice storage type chilled water device that can be performed.

[0005]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and the invention according to claim 1 is a refrigerator, a supercooled water heat exchanger, and an ice storage tank. The method for controlling an ice storage type chilled water device according to claim 1, wherein the cooling target at an outlet of the supercooled water heat exchanger is detected based on a detection value of a flowing water amount detection means provided in a chilled water extraction line of the ice storage tank. It is characterized in that water is controlled to a temperature that does not cause supercooling.

[0006]

Next, an embodiment of the present invention will be described. The present invention relates to a method for controlling an ice storage type chilled water device, and more particularly to an ice storage type chilled water device corresponding to the water level in the ice storage tank and the amount of chilled water required on the load side during the operation of taking out chilled water from the ice storage tank. Control method,
The ice storage type chiller is operated efficiently. The present invention provides a supercooled water heat exchanger (hereinafter, referred to as "heat exchanger") depending on the level of water in the ice storage tank and the amount of cold water taken out during the operation of taking out cold water from the ice storage tank. This is realized by controlling the temperature of the water to be cooled. The water level in the ice storage tank fluctuates depending on the required amount of cold water required on the load side and the amount of deicing water supplied to defrost the stored ice. Therefore, when the amount of cold water required on the load side is small, the water level in the ice storage tank does not decrease so much and is at a high water level, and the supercooled water refluxed from the heat exchanger hits the ice storage surface. It rises as ice bamboo shoots and reaches the outlet of the heat exchanger and freezes. In the present invention, the chilled water control of the ice storage type chilled water device during the operation of taking out chilled water from the ice storage tank is performed. By controlling the temperature of the water to be cooled at the outlet of the heat exchanger to a temperature that does not cause supercooling based on the detection value of the flow rate detecting means provided on the cold water extraction line of the ice storage tank, To prevent the freezing of the ice and improve the operation efficiency of the ice storage type chilled water device.

[0007] The ice storage type chiller is composed of a refrigerator, a heat exchanger and an ice storage tank.
The lower part of the ice storage tank and the inlet of the heat exchanger are connected by a cold water supply line, a temperature sensor and a heating means are provided in the cold water supply line, and a water level detecting means is provided in the ice storage tank. A cold water intake line is connected to a lower part of the ice tank, and the cold water intake line is provided with a flow rate detecting means. The temperature sensor, the heating means, the water level detecting means and the flow rate detecting means are connected to a controller. Further, as the heating means,
A configuration in which a hot water supply line is connected to the cold water supply line,
There are a configuration in which an electric heater is provided, a configuration in which a high-temperature refrigerant of the refrigerator is used, and the like. As the water level detecting means, there are an electrode rod method, a float method and the like. Further, as the flow rate detecting means, not only a flow sensor for simply detecting the flow of the chilled water in the chilled water extraction line, but also a form which also serves as a flow rate sensor, a water intake pump for extracting the cooling water, an electromagnetically opened / closed or adjusted. A discharge valve or the like is used, which can directly detect the flow of the cooling water and can detect the flow as a flow by the output.

Further, during the operation of taking out cold water from the ice storage tank, it is necessary to completely prevent freezing in the heat exchanger. Therefore, the controller is provided in a cold water take-out line of the ice storage tank. Based on the detection of the flow rate detecting means, the temperature of the water to be cooled is controlled to a temperature that does not cause supercooling at the outlet of the heat exchanger. When the water level in the ice storage tank during the operation of taking out cold water from the ice storage tank is higher than a predetermined water level, the controller sets the temperature of the water to be cooled to a temperature at which the cooling water is not supercooled at the outlet of the heat exchanger. To control. Further, when the temperature is lower than a predetermined water level, the controller controls the temperature of the water to be cooled to a temperature at which supercooling is performed at the outlet of the heat exchanger, and supplies supercooled water to the ice storage tank to make ice. . Therefore, a large amount of cooling water can be immediately obtained by supplying the deicing water from outside to the supercooling water.

The heat exchange temperature of the water to be cooled at the inlet and the outlet of the heat exchanger is, for example, if the inlet temperature is 0.8 ° C., the outlet temperature is -0.9 ° C., and the outlet temperature is supercooled water. Is 1.8 ° C., the outlet temperature is 0.1 ° C. cold water. That is, in this heat exchanger, the cooling temperature due to the heat exchange of the water to be cooled at the inlet and the outlet is 1.7 ° C.
Therefore, the outlet temperature at which supercooling does not occur at the outlet of the heat exchanger is set to 0.1 ° C., and the outlet temperature at which supercooling water is obtained is set to −0.1.
By controlling the temperature to 9 ° C., it is possible to respond to the required amount of chilled water on the load side and efficiently operate the ice storage type chilled water device.

[0010]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is an explanatory diagram showing a configuration of an embodiment of an ice storage type chilled water device embodying the present invention.

Referring to FIG. 1, the ice storage type chilled water apparatus includes a refrigerator 1, a supercooled water heat exchanger 2 (hereinafter, referred to as a "heat exchanger 2"), and an ice storage tank 3. The refrigerator 1 is of a system in which, for example, a liquefied refrigerant (for example, chlorofluorocarbon) is decompressed by an expansion valve 1a, and then the water to be cooled is cooled by the latent heat of evaporation of the refrigerant via the heat exchanger 2. As shown in FIG. 1, the heat exchanger 2 has a double pipe structure in which an outer pipe 2a is formed in a spiral shape and an inner pipe 2b is inserted therein, and the outer pipe 2a and the inner pipe 2b The cooling water supplied from the ice storage tank 3 flows between the inner pipe 2 and the inner pipe 2.
The refrigerant supplied from the refrigerator 1 flows through b.
Accordingly, the water to be cooled is cooled from the outer periphery of the inner pipe 2b to be supercooled water, and the supercooled water flows into the ice storage tank 3 where it is frozen.

The refrigerator 1 and the inner tube 2b are
The refrigerant is connected by a refrigerant supply line 4 and a refrigerant recirculation line 5 via the expansion valve 1a, so that the refrigerant circulates between the two. on the other hand,
The lower part of the ice storage tank 3 and the inlet of the outer tube 2a are connected by a cold water supply line 6, and the outlet of the outer tube 2a and the ice storage tank 3 are connected by a supercooled water return line 7, respectively. A temperature sensor 8, an electric heater 9 as a heating means, and a circulation pump 10 are inserted into the cold water supply line 6.

The ice storage tank 3 is provided with an electrode rod type water level detecting device 11 as water level detecting means. The water level detecting device 11 has an upper limit water level (S bar),
It is composed of three electrode rods of S, M, and L for detecting the intermediate water level (M rod) and the lower limit water level (L rod), respectively. The predetermined water level applied by the control method described later is the intermediate water level (M rod).
Bar). Further, a cold water intake line 12 is connected to the lower part of the ice storage tank 3, and this cold water intake line 1
2 is provided with a water intake pump 14 as a flow rate detecting means 13 and a flow rate sensor 15, and a water supply line 16 is connected to an upper part thereof. The temperature sensor 8, the electric heater 9, the water level detecting device 11, the water intake pump 14, and the flow sensor 15 are connected to a controller 18 via a signal line 17.

Next, an operation method of the ice storage type chilled water device having the above configuration will be described. This ice storage type chiller stores ice in the ice storage tank 3 by using late-night electric power at a low electricity rate, and supplies water to the upper part of the ice storage tank 3 in response to a request from the load side. A predetermined amount of deicing water is supplied from a line 16, and chilled water is supplied to a load side from a chilled water intake line 12 connected to a lower portion. The detection of the flow by the flow rate detecting means 13 is input to the controller 18 simultaneously with the supply of the chilled water to the load side, and the ice storage type chilled water device is activated.

By the way, the control method of the ice storage type chilled water device during the operation of taking out the chilled water from the ice storage tank 3 is to completely prevent the freezing in the heat exchanger 2 during the chilled water taking out operation and to control the load. Supply cold water at a cold water temperature (for example, 0.1 ° C.) that does not result in supercooling required by the
This is to operate the ice storage type chilled water device efficiently. That is, the controller 18 detects the intake of the chilled water extraction line 12 by the flow rate detection means 13 by the intake from the chilled water extraction line 12, and based on the detected value and the detection signal of the temperature sensor 8, The electric heater 9 is operated to adjust the amount of heating of the cold water supply line 6, and the inlet temperature of the heat exchanger 2 is set to a preset water temperature (for example, 1.8 ° C.) into the heat exchanger 2. Then, cold water at a predetermined temperature (0.1 ° C.) is returned to the ice storage tank 3.

Next, when the water level in the ice storage tank 3 during the cold water removal operation is higher than the intermediate water level (M bar), the controller 18 controls the detection signal of the temperature sensor 8 in the same manner as described above. , The electric heater 9 is operated to adjust the amount of hot water flowing into the chilled water supply line 6, and the inlet temperature of the heat exchanger 2 is set in advance.
At a temperature (0.1 ° C.) at which supercooling does not occur. In addition, the ice storage tank 3 during the cold water removal operation.
When the inside water level is lower than the intermediate water level (M bar) and the flow rate of the chilled water supplied from the chilled water intake line 12 is equal to or less than a predetermined amount set in advance, the controller 18 outputs a signal from the flow rate sensor 15. , The amount of heating of the electric heater 9 is adjusted, and the temperature of the water to be cooled flowing into the heat exchanger 2 from the cold water supply line 6 is set at the outlet of the heat exchanger 2 where the cooling water is preset. The temperature at which water becomes -0.9 ° C. In this control method, when the water level is lower than the intermediate water level and the amount of cold water taken out is small, the amount of cold water in the ice storage tank 3 increases. For this reason, when the supply of the deicing water from the water supply line 16 to the supercooled water in the ice storage tank 3 is started or the supply amount is increased, the cooling water is immediately increased and the cooling water is supplied to the cold water discharge line 12. Can take water.

When the intake pump 14 is used for extracting cold water from the flow rate detecting means 13, if the intake pump 14 starts and stops in a short time, a hunting phenomenon easily occurs in the control temperature. Therefore, it is possible to set a stop confirmation time of the intake pump 14. Even when the start and stop of the water intake pump 14 are repeated in a short time, by adjusting the stop confirmation time of the water intake pump 14, the temperature of the cold water in the ice storage tank 3 is stabilized without being supercooled. be able to.

As described above, when the ice storage type chilled water device is operated according to the control method, based on the detection by the flow rate detecting means 13 of the ice storage tank 3, the chilled water amount requested by the load side is determined. From the ice storage tank 3 to the heat exchanger 2
Since the temperature of the water to be supplied to the heat exchanger 2 is controlled to a preset temperature and the outlet temperature of the heat exchanger 2 is returned as cold water or supercooled water, the ice storage type chilled water device can be operated efficiently.

[0019]

As described above, according to the present invention, there is provided a control method for taking out cold water from an ice storage tank. By detecting the extraction of cold water to the extraction line, the temperature of the water to be cooled is controlled to a temperature that does not cause supercooling at the outlet of the supercooled water heat exchanger. The type cooling water device can be operated efficiently. Moreover, the amount of cold water taken out can be increased, the temperature difference between water and the refrigerant can be reduced, and the heat exchange capacity can be increased.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing a configuration of an embodiment of an ice storage type chilled water device embodying the present invention.

FIG. 2 is an explanatory diagram showing a configuration of a conventional ice storage type chilled water device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Refrigerator 2 Heat exchanger for supercooled water 3 Ice storage tank 12 Cold water extraction line 13 Flow rate detection means

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3L060 AA03 CC15 DD01 EE34 EE35 EE41 3L110 AB00 AB04 AC04

Claims (1)

[Claims] 1. A method for controlling an ice storage type chilled water device comprising a refrigerator 1, a supercooled water heat exchanger 2 and an ice storage tank 3, wherein the method is provided in a chilled water extraction line 12 of the ice storage tank 3. A method for controlling the temperature of the water to be cooled at the outlet of the supercooled water heat exchanger 2 so as not to be supercooled, based on the detected value of the flow rate detecting means 13.