JPH11294800A - Control method and ice storage detector for ice storing water chiller - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a control method and an ice storage detector for enhancing ice storage efficiency and ice filling rate of the ice storage tank in an ice storage water chiller. SOLUTION: In the control method for an ice storage water chiller comprising a refrigerating machine 1, a supercooling heat exchanger 2 and an ice storage tank 3, operation of the ice storage water chiller is stopped based on the detection signal from a detecting means provided for the ice storage tank 3 and operation thereof is resumed upon elapsing a specified time after stopping operation. Subsequently, operation of the ice storage water chiller is stopped based on the detection signal from a detecting means and the sequence is repeated automatically. An ice storage detector has a reference electrode and an earth electrode disposed in the ice storage tank 3 while being connected through a resistance measuring unit 15.

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 an operation control method for an ice storage type chilled water device and an ice storage detecting 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 cooler. As shown in FIG. 2, the ice storage type chiller communicates between an ice storage tank 31 and a supercooled water heat exchanger 32 (hereinafter, referred to as a “heat exchanger 32”) through a chilled water circulation path 33. And the heat exchanger 3
2 and a refrigerator 34 are connected by a refrigerant circulation path 35. This 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 supplies deicing water from above the ice storage tank 31 in response to a load request. Cold water is taken out from the lower part of the tank 31.

[0003] Incidentally, the operation of this ice storage type chilled water device is as follows.
After the ice storage tank 31 is filled with water to a predetermined water level, the refrigerator 34 is started and the cooling medium is supplied to the heat exchanger 32.
The ice storage tank 31
The water to be cooled is sent to the heat exchanger 32 for heat exchange, and the supercooled water is returned to the ice storage tank 31. Then, after storing a predetermined amount of ice in the ice storage tank 31, the operation of the ice storage type chilled water device is stopped. Here, as means for determining that a predetermined amount of ice has been stored in the ice storage tank 31 (an allowable volume of ice in the ice storage tank 31), conventionally, an experimentally calculated value in the ice storage tank 31 is used. The time elapsed from the start of the ice storage operation is set in advance by indirectly predicting from the water level drop value and the operation time until the predetermined amount of ice is stored. However, in the control based on the ice storage operation time, the ice storage space in the ice storage tank 31 is changed due to a change in ice shape in the ice storage tank 31 or an external factor (for example, freezing in the heat exchanger 32). Even if there is, the ice storage operation is stopped. Therefore, the operation is not efficient as the ice storage type chiller.

[0004]

SUMMARY OF THE INVENTION In view of the above-mentioned problems, the present invention improves the ice storage efficiency of an ice storage tank and controls a method of controlling an ice storage type chilled water device for increasing the filling rate of ice in the ice storage tank. And an ice storage detecting device.

[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. A method of controlling an ice storage type chilled water device, comprising: stopping the operation of the ice storage type chilled water device based on detection means provided in the ice storage tank; Restart the operation of the ice storage chiller, and after the restart,
The operation of stopping the operation of the ice storage type chilled water device is automatically repeated based on the detection signal of the detection means, and the invention according to claim 2, wherein the refrigerator,
An ice storage detecting device in an ice storage type chilled water device including a supercooled water heat exchanger and an ice storage tank, wherein a reference electrode and an earth electrode provided in the ice storage tank are connected through an electric resistance measuring device. Further, the invention according to claim 3 is characterized in that the reference electrode is a subcooling release member.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment of the present invention will be described. The present invention is realized in an ice storage type chilled water device constituted by a refrigerator, a supercooled water heat exchanger and an ice storage tank. You.

The ice storage type chilled water device communicates between the ice storage tank and a supercooled water heat exchanger (hereinafter, referred to as a "heat exchanger") by a chilled water circulation path provided with a circulation pump. The heat exchanger and the refrigerator are configured to communicate with each other via a refrigerant circuit.

The ice storage detecting device according to the present invention focuses on the difference in electric resistance between the reference electrode and the ground electrode, and measures the electric resistance to determine the height of the ice in the ice storage tank. (Ice storage). That is, the nozzle of the chilled water circulation path is extended to a predetermined position in the upper part of the ice storage tank, and a subcooling release member serving also as a reference electrode is provided below the nozzle. Also, an earth electrode is provided near the side wall in the ice storage tank, and the earth electrode and the supercooling release member are connected by a signal line via an electric resistance measuring device. The electric resistance measuring device is connected to a controller via a signal line. Further, a cold water intake channel for supplying cold water to the load side is connected to a lower portion of the ice storage tank. Further, a thawing pipe is provided above the ice storage tank. Furthermore, a reference electrode may be provided alone near the supercooling release member.

According to the control method of the ice storage type chilled water device having the above-described structure, after the ice storage tank is filled with water to a predetermined water level, the refrigerator is started and the cooling medium is supplied to the heat exchanger and circulated. At the same time, an ice storage operation is performed in which the water to be cooled in the ice storage tank is sent into the heat exchanger to exchange heat, and supercooled water is returned to the ice storage tank to store ice. Then, as time elapses, ice is gradually stored in the ice storage tank. During this ice storage operation, the recirculating supercooled water collides with the supercooling release member and scatters, and a part of the supercooled water freezes.
Therefore, the supercooled release member (reference electrode) and the ground electrode are connected by the scattered supercooled water and the water surface, and the electric resistance value is high. By the way, in the ice storage tank, sherbet-like ice floats on the water surface, and the ice rises on the sherbet-like ice as icicles toward the supercooling release member. The raised ice bamboo shoot grows while repeatedly collapsing and rising due to its own weight, and approaches the supercooled release member. When the tip of the ice bamboo shoot contacts the supercooling release member, the ground electrode is connected to the ground electrode by the ice bamboo shoot, and the electric resistance value decreases. Therefore, the electric resistance value is set in advance, and when the electric resistance measuring device detects the electric resistance set value during the ice storage operation, it is determined that a predetermined amount of ice has been stored in the ice storage tank, and the ice storage type is stored. Stop the operation of the chiller.

[0010] The ice bamboo shoots in the ice storage tank gradually dissolve in the water in the ice storage tank over time, forming sherbet-like ice and forming a sherbet layer below the water surface. Therefore, the control method according to the present invention provides a control method for a predetermined time (for example,
After one hour), the operation is automatically restarted. The operation stop and the operation restart are repeated until a predetermined amount of ice (an allowable amount of ice storage in the ice storage tank) is stored in the ice storage tank. In addition, the supply of cold water from the ice storage tank is performed by spraying room temperature water (for example, tap water) from a thawing pipe provided above the ice storage tank, and opening a valve of a cold water intake channel provided below. Supply cold water to the load side. At the time of supplying the cold water, if the required amount on the load side is large, an ice storage operation similar to the above, that is, a so-called follow-up operation is performed.

As described above, the operation of the ice storage type chilled water device is stopped based on the detection signal of the ice storage device provided in the ice storage tank, and the operation is restarted after a lapse of a predetermined time from the stop of the operation.
After the restart, based on the detection signal of the ice storage detection device, since the operation to stop the operation is automatically repeated,
The ice storage efficiency of the ice storage tank can be increased.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, specific embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is an explanatory diagram schematically showing the configuration of an ice storage type chiller according to the present invention.

In FIG. 1, the ice storage type chilled water apparatus includes a refrigerator 1, a heat exchanger 2 for supercooled water (hereinafter, referred to as a “heat exchanger 2”), and an ice storage tank 3. The refrigerator 1 is of a type in which, for example, after liquefied refrigerant is depressurized by an expansion valve (not shown), the water to be cooled is cooled by the latent heat of evaporation of the refrigerant via the heat exchanger 2. The heat exchanger 2 has a double pipe structure in which an outer pipe (not shown) is formed in a spiral shape and an inner pipe (not shown) is inserted therein, and the heat exchanger 2 is provided between the outer pipe and the inner pipe. The cooling water supplied from the ice storage tank 3 flows, and the refrigerant supplied from the refrigerator 1 flows in the inner pipe. Therefore, the water to be cooled is cooled from the outer circumference of the inner pipe 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 pipe are connected by a refrigerant supply path 4 and a refrigerant return path 5 so that the refrigerant circulates between them. On the other hand, a lower part of the ice storage tank 3 and an inlet of the outer tube are connected by a cold water supply passage 6, and a space between the outer tube outlet of the heat exchanger 2 and the ice storage tank 3 is a supercooled water return passage 7. The circulation pump 8 is provided in the cold water supply path 6. A cold water intake passage 9 for supplying cold water to the load side and a makeup water supply passage 10 are connected to a lower portion of the ice storage tank 3. Further, a thawing pipe 11 is provided above the ice storage tank 3.

As shown in FIG. 1, the ice storage detecting device according to the present invention also functions as a reference electrode below the nozzle 12 of the supercooled water recirculation passage 7 extending to a predetermined upper position in the ice storage tank 3. A subcooling release member 13 is provided, and an earth electrode 14 is provided near the side wall of the ice storage tank 3. The ground electrode 14 and the subcooling release member 13 are connected by a signal line 16 via an electric resistance measuring device 15. doing. The electric resistance measuring device 15 is connected to a controller 17 via a signal line 16. The refrigerator 1 and the circulation pump 8 are connected to the controller 1 via a signal line 16.
7 respectively.

Next, the operation of the ice storage detecting device will be described. The ice storage detecting device measures an electric resistance value between the reference electrode (also used as the supercooling release member 13 in this embodiment) and the ground electrode 14, and sets a preset electric measurement value. Is reached, it is detected that a predetermined amount of ice has been stored in the ice storage tank 3. That is, during the ice storage operation, the recirculating supercooled water hits the supercooling release member 13 from the nozzle 12 and scatters, and a part of the supercooled water freezes. Therefore, the supercool release member 13 and the ground electrode 14
Are electrically connected to the water surface by the water flowing through the circulation pump 8, the cold water supply path 6, the heat exchanger 2, the supercooled water return path 7, and the nozzle 12. , The electrical resistance increases. By the way, in the ice storage tank 3, as time passes, sherbet-like ice floats on the surface of the water, and on the ice on the sherbet, ice forms icicles toward the supercooling release member 13. Uplift. The raised ice bamboo shoots grow while repeating collapse and uplift due to their own weight, and approach the supercooling release member 13. The tip of the ice bamboo shoot is the supercooling release member 1
3, the supercool release member 13 and the ground electrode 14 are connected by icicles.
The electric resistance value becomes lower than during the ice storage operation. The electric resistance value is set in advance, and a signal is transmitted when the set value is detected.

Next, a control method of the ice storage type chiller provided with the ice storage detecting device will be described. First, raw water is supplied from the makeup water supply passage 10 to a predetermined water level of the ice storage tank 3 (controlled by a water level control device (not shown)). Thereafter, the controller 17 outputs a start signal to the refrigerator 1 and starts the circulation pump 8. When the refrigerator 1 and the circulation pump 8 are driven, the water in the ice storage tank 3 is supercooled through the heat exchanger 2 and the supercooled water return path 7
Then, an ice storage operation of returning to the ice storage tank 3 as supercooled water is performed. Then, the operation of the refrigerator 1 and the circulation pump 8 is stopped based on the detection signal of the ice storage detecting device. After a lapse of a predetermined time (for example, one hour) from the stop of the operation, the refrigerator 1 and the circulation pump 8 are restarted. After the restart, similarly to the above, the operation of stopping the refrigerator 1 and the circulation pump 8 is repeatedly performed based on the detection signal of the ice storage detecting device. By this repetitive operation, the ice storage efficiency in the ice storage tank 3 can be improved.

At a predetermined time after the operation is stopped, the ice bamboo shoots rising in the ice storage tank 3 are gradually melted with the passage of time to form sherbet-like ice and form a sherbet layer below the water surface. I do. By repeating the formation and melting of the ice bamboo shoots, a predetermined ice storage amount can be secured in the ice storage tank 3. Thus, in the state where the ice storage amount is secured, the supercooling release member 13
And the ice bamboo abut, the refrigerator 1 and the circulation pump 8 are stopped.

The supply of cold water from the ice storage tank 3 is performed by sprinkling room-temperature water (a supply source is not shown) from a thawing pipe 11 provided above the ice storage tank 3 based on a request from the load side. Then, the valve of the cold water intake passage 9 provided at the lower portion is opened to supply the cold water to the load side. If the required amount on the load side is large during the supply of the cold water, the ice storage operation similar to the above, that is, the so-called follow-up operation is performed.

[0020]

As described above, according to the present invention, there is provided a method for controlling an ice storage type chilled water device comprising a refrigerator, a heat exchanger for supercooled water and an ice storage tank, and an ice storage detecting device. Stopping the operation of the ice storage type chilled water device based on a detection signal of the ice storage device provided in the ice storage tank, and operating the ice storage type chilled water device after a lapse of a predetermined time from the stop of the operation. And after the restart, the operation of stopping the operation of the ice storage type chilled water device is automatically repeated based on the detection signal of the ice storage detection device, so that the ice storage efficiency in the ice storage tank is reduced. As well as improving the ice filling rate.

[Brief description of the drawings]

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

FIG. 2 is an explanatory view schematically 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 (heat exchanger) 3 Ice storage tank 13 Subcooling release member (reference electrode) 14 Earth electrode 15 Electric resistance measuring instrument

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Yoshio Hashimoto 7th Horie-cho, Matsuyama-shi, Ehime

Claims (3)

[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, based on detection means provided in the ice storage tank 3. Stopping the operation of the ice storage chilled water device, restarting the operation of the ice storage chilled water device after a lapse of a predetermined time from the stop, and restarting the ice storage chilled water device based on a detection signal of the detection means. A method for controlling an ice storage type chiller, wherein the operation of stopping the operation of the chiller is automatically repeated. 2. An ice storage detecting device in an ice storage type chilled water device comprising a refrigerator 1, a supercooled water heat exchanger 2 and an ice storage tank 3, wherein a reference provided in the ice storage tank 3 is provided. An ice storage detecting device for an ice storage type cold water device, wherein an electrode and an earth electrode 14 are connected via an electric resistance measuring device 15. 3. The ice storage detecting device according to claim 2, wherein the reference electrode is a supercool release member.