JP2004084963A - Ice heat accumulator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To quickly and accurately replenish water in response to a change in a holding water quantity: and to perform stable ice making operation without having influence by a change in a water level in a water tank. <P>SOLUTION: The inside of an ice heat accumulating tank 1 stores ice generated by an ice maker 2 together with ice making water, and has a water level sensor 12 for detecting the water level in the tank and a full ice sensor 15 for detecting whether or not the storage height of the ice stored in the tank reaches the height of a preset full ice state, and has a control circuit 4 for controlling replenishment of the water so as to maintain the water level in the tank in a prescribed range on the basis of a signal from the water level sensor and stopping ice making operation by receiving a signal for indicating that the ice reaches the height of the full ice state from the full ice sensor when performing the ice making operation, and individually controls the water level in the tank and an ice storage quantity. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an ice heat storage device, and more particularly, to an ice heat storage device capable of appropriately maintaining the amount of water held in a heat storage tank.
[0002]
[Conventional technology and its problems]
The ice heat storage tank was produced by a static type that freezes the water in the tank around the cooling pipes arranged in the heat storage tank, and an ice making machine that led out the water in the tank to an ice machine outside the tank. There is a dynamic type that accumulates small or small pieces of ice in the tank, and this dynamic type does not require a cooling pipe in the tank as in the case of the static type, and almost all the volume of the ice is stored in the tank. It can be used for storage, so it can be smaller than the static type if the heat storage capacity is the same, and since the ice is small or small, the contact area with water is large, The heat transfer efficiency is better than that of the static type, in which ice blocks are formed around the cooling pipes.Furthermore, the ice making machine can be of various types, such as supercooling type or ice scraping type. Can be freely selected according to the scale There are various advantages not to those of the static type as referred to.
[0003]
By the way, in the dynamic type, the ice supplied to the tank is not only floating and stored on the surface of the water, but also the ice adheres to the inner wall of the tank or the lower part of the ice reaches the inner bottom of the tank, Ice larger than the volume expansion accompanying the phase change from water to ice is stored at a position higher than the water surface, and the water level decreases as the ice filling rate increases.
[0004]
Therefore, in the dynamic type, the water level in the tank is directly detected, or the change in the water level is indirectly detected from the change in the suction side pressure of the ice making pump for supplying the water in the tank to the ice making machine. The filling rate of ice can be determined.
[0005]
It is also possible to determine the ice filling rate from the ice making capacity of the ice making machine and its driving time, or to measure the temperatures at the ice making water inlet and the ice outlet sides of the ice making machine and determine the ice filling rate from these temperature changes. There is also a way to do it.
[0006]
However, when the operation control of the ice maker is performed based on the ice filling rate obtained by the above-described method, it is a precondition that there is no change in the water holding amount of the entire apparatus. In order to prevent the malfunction, it is necessary to periodically measure the water level in the ice heat storage tank and replenish the water as needed, in order to prevent the malfunction.
[0007]
Therefore, in the conventional apparatus, in the end of the defrosting operation in which the filling rate of ice becomes the minimum, for example, in the case of storing heat by the ice making operation using night power, the water level is measured immediately before the ice making operation at night and the water is measured to a predetermined water level. Replenishing.
[0008]
However, if the change in the amount of retained water is small, such as a decrease due to evaporation of water, regular water replenishment as described above will suffice.However, the water supply path from the cold water supply path to the load-side heat exchanger Is discharged, for example, disassembly and cleaning of the load side heat exchanger is frequently performed in a facility such as a food factory where strict sanitary management is required, and water from the ice heat storage device is removed every time this disassembly and cleaning is performed. In the case where the amount of water retained is greatly changed by being discharged, the water level of the ice heat storage tank is not stabilized by the above-mentioned regular replenishment of water, and the control of the ice making operation is hindered. Replenishing the same amount of water as the discharged water into the ice thermal storage tank can secure the specified amount of water, but it is complicated and difficult to manage the exact amount of drainage and replenish the same amount of water. However, even if the amount of drainage is sufficiently controlled, if the number of times of drainage and replenishment increases, the error increases, and it is difficult to keep the amount of water retained in a certain range.
[0009]
【Purpose】
It is an object of the present invention to supply water quickly and accurately in response to a change in the amount of water held in the apparatus, and to control the ice making operation to malfunction due to a change in water level. An object of the present invention is to provide an ice heat storage device that can be performed stably without any problem.
[0010]
Configuration of the Invention
In order to achieve the above object, an ice heat storage device according to the present invention includes an ice heat storage tank that stores water and ice, freezes water sent from the ice heat storage tank to generate ice, and stores the ice in ice heat storage. Cold water that supplies ice to the tank and water cooled by the ice stored in the tank in the ice heat storage tank to the load side, and returns the water that has exchanged heat on the load side to the ice heat storage tank again A supply path, and a water level sensor for detecting a water level in the ice heat storage tank, and a storage height of ice stored in the tank is set to a predetermined full ice height. A full ice sensor for detecting whether or not the water level has been reached is provided.Based on a signal from the water level sensor, water supply to the ice heat storage tank is controlled so that the water level in the ice heat storage tank is maintained within a predetermined range. And that the ice has reached the full ice level from the full ice sensor during the ice making operation of the ice making machine. A control circuit that allowed to stop the operation of the ice making machine by receiving a signal indicating the water level and ice of the ice thermal storage tank is as being configured to be individually controlled.
[0011]
【Example】
Hereinafter, an embodiment of an ice heat storage device according to the present invention will be described based on a specific example shown in the accompanying drawings.
In the drawing, reference numeral 1 denotes an ice heat storage tank, 2 denotes an ice making machine, 3 denotes a load side heat exchanger, 4 denotes a control circuit, and the other end of an ice making water pipe 5 having one end connected to the lower part of the ice heat storage tank 1 is connected to the other end. The other end supply port 6a of the ice supply pipe 6 connected to the water inlet of the ice maker 2 via the ice maker pump P1 and having one end connected to the ice outlet of the ice maker faces the inside of the ice heat storage tank.
[0012]
The ice maker 2 sub-cools water from an ice heat storage tank to about -2 ° C., and releases the super-cooled state by applying appropriate vibrations from outside to a pipe through which the super-cooled water passes. Or so-called sherbet-like ice in which small-grained ice and water are mixed.
[0013]
The other end of the cold water outgoing pipe 7 having one end connected to the lower part of the ice heat storage tank 1 is connected to the cold water inlet 3a of the load side heat exchanger 3 via the cold water pump P2, and one end is connected to the same outlet 3b. The other end of the cooled cold water return pipe 8 is connected to a water sprinkling pipe 9 arranged at the upper part in the ice heat storage tank 1, sends cold water from the ice heat storage tank to the load side, and exchanges heat with the load side. A chilled water circulation path for returning the water to the ice heat storage tank is configured.
[0014]
Further, a replenishing water pipe 10 for supplying water from outside to the inside of the tank is provided on the upper side surface of the ice heat storage tank 1. The replenishing water pipe is provided with an opening / closing valve 11 on the way. It is opened and closed by an opening and closing control signal from the controller.
[0015]
In the ice heat storage tank 1, four support rods having different lengths extend downward from a base attached to a top plate 1a of the tank, and the tip of each support rod is closed by contact with water. A water level sensor 12 including electromagnetic type liquid contact switches S1, S2, S3, and S4 is provided. The first liquid contact switch S1 provided at the lowest position detects an abnormal decrease in the water level in the tank, and The lower second liquid contact switch S2 detects the lower limit water level during normal operation of the device, and the third upper liquid contact switch S3 above it detects the upper limit water level during normal operation of the device. The fourth liquid contact switch S4 is configured to detect an abnormal rise in the water level in the tank.
[0016]
In addition, the liquid contact switch is covered with a cylindrical cover with a lower part opening around the whole switch or around each switch so that it does not close due to contact with ice, so that only water enters the cover and ice does not enter. It is desirable.
[0017]
The water level sensor 12 is connected to the control circuit 4 by a water level signal line 13, and the control circuit is connected to the open / close valve 11 of the makeup water pipe 10 by an open / close signal line 14. The open / close valve 11 is controlled to open and close based on the water level signal of the above, and the amount of water in the tank is properly maintained by the open / close control. A specific example thereof will be described later.
[0018]
In addition, in the ice heat storage tank 1, apart from the water level sensor 12, a full ice sensor 15 for detecting whether or not the ice stored in the tank has reached a predetermined full ice height. This full ice sensor is provided with a base attached to the top plate 1a of the ice heat storage tank, and a tape for keeping the temperature sensing part at, for example, about 10 ° C. around a temperature sensing part 15a of a rod-shaped temperature sensor extending downward. It is assumed that an electric heater 15b is attached.
[0019]
The full ice sensor detects whether or not the ice has reached the height of the temperature sensing part, that is, a predetermined height, based on a difference in temperature depending on whether or not the ice 22 is in contact with the temperature sensing part 15a, Specifically, when the temperature sensing part is not in contact with the ice, the temperature of about 10 ° C. is detected by the heat from the electric heater even if the air temperature in the tank is almost the same as the temperature of the ice, When the ice storage amount increases and ice comes into contact with the temperature-sensitive portion, heat from the electric heater is taken by the ice, and the temperature of the temperature-sensitive portion becomes lower than the temperature of ice, that is, 0 ° C.
[0020]
The full ice sensor is provided near the other end supply port 6a of the ice water supply pipe 6 and at a position lower than the supply port so that the temperature sensing portion 15a can detect the highest position of ice.
[0021]
The temperature signal from the above-mentioned full ice sensor 15 is sent to the control circuit 4 by a temperature signal line 16, and an ice making control signal line 17 is provided between the control circuit and the ice making machine 2. A drive control signal line 23 is provided between the ice making pump P1 and the control circuit for controlling the operation and stop of the ice making machine 2 and the ice making pump P1 based on the temperature detected by the full ice sensor. The specific control will be described later.
[0022]
On the way of the cold water outgoing pipe 7 and the cold water return pipe 8 for sending cold water to the load side heat exchanger 3, normally open on-off valves 18 and 19 are respectively provided. 3, a drainage branch pipe 20 having a normally closed drainage valve 20a and an air release branch pipe 21 also having a normally closed air release valve 21a are provided. When the load side heat exchanger 3 is washed or inspected, the on-off valves 18 and 19 are manually closed, the drain valve 20a and the air release valve 21a are opened, and the water in the load side heat exchanger is discharged from the drain branch pipe 20. To remove the heat exchanger.
[0023]
Next, the operation of the ice heat storage device of the present invention configured as described above will be described. The water in the ice heat storage tank 1 is sent to the ice maker 2 by driving the ice maker pump P1, and after being supercooled to about -2 ° C in the ice maker, the supercooled state is released and ice and water are mixed. It becomes sherbet-like ice and is sent into the ice thermal storage tank 1 by the ice supply pipe 6 and stored in the thermal storage tank.
[0024]
The water cooled by the ice in the ice heat storage tank 1 is sent to the load-side heat exchanger 3 via the cold water outgoing pipe 7 by driving the cold water pump P2, and heat-exchanges with an appropriate load in the heat exchanger. The water is sent to the water sprinkling pipe 9 in the ice heat storage tank 1 by the return pipe 8, and is sprayed on the ice 22 from a number of water sprinkling ports opened in the water sprinkling pipe and returned to the tank.
[0025]
The water level in the ice heat storage tank 1 is maintained within a predetermined range by the water level sensor 12, and the reference water level is determined by the second liquid contact switch S2 and the third liquid contact switch S3. In this state, the first and second liquid contact switches are closed, and the third and fourth liquid contact switches are open.
[0026]
The open / closed state of each liquid contact switch in the water level sensor 12 is sent to the control circuit 4 by the water level signal line 13. First, the first liquid contact switch S1 is closed, and the fourth liquid contact switch S4 is opened. It is checked that it is in a certain normal operation state. If the first liquid contact switch S1 is open, it is determined that the water level is abnormally low. If the fourth liquid contact switch S4 is closed, the water level is low. Is determined to be abnormally high, an appropriate alarm is issued, and the device is emergency-stopped as necessary.
[0027]
Thus, in the normal operation state where the first liquid contact switch S1 is closed and the fourth liquid contact switch S4 is open, the control circuit 4 switches the second and third liquid contact switches to the open / close state. Water supply control is performed accordingly.
[0028]
Specifically, when the water level is lower than the second liquid contact switch in a normal state and the switch is opened, the control circuit 4 sends the open / close valve 11 of the makeup water pipe 10 via the open / close control signal line 14. Is opened, water is replenished into the ice heat storage tank 1 to raise the water level. When the water level rises, the second liquid contact switch S2 is closed, and when the third liquid contact switch S3 is further closed, the open / close valve 11 is closed. Close to stop water supply.
[0029]
The operation control of the ice making machine 2 is performed by an operation control signal from the control circuit 4 based on a temperature signal from the full ice sensor 15 and is usually set at a preset time or the temperature of the cold water in the cold water outgoing pipe 7. When the rise is detected and the ice making operation of the ice making machine is started, and the control circuit 4 detects that the height of the ice has reached a preset full ice state height based on a signal from the full ice sensor, The ice making operation in the ice making machine 2 is stopped by a signal from the control circuit.
[0030]
The driving of the ice making pump P1 is also controlled according to the operation control of the ice making machine 2.
Specifically, if the detected temperature sent from the full ice sensor 15 to the control circuit 4 is equal to or higher than a predetermined temperature higher than 0 ° C., for example, 2 ° C., the ice 22 is not in contact with the full ice sensor 15. That is, the control circuit 4 determines that the ice filling amount has not yet reached the predetermined value, and continues the ice making operation of the ice making machine 2.
[0031]
When the ice filling amount increases with the progress of the ice making operation and the upper surface of the ice 22 comes into contact with the temperature sensing portion 15a of the full ice sensor 15, an electric heater 15b that keeps the temperature sensing portion at about 10 ° C. The heat is deprived of the ice, and the temperature sensing portion 15a becomes the temperature of the ice, that is, the temperature of 0 ° C. or less. The detected temperature of 0 ° C. or less is sent to the control circuit 4 by the temperature signal line 16 and the ice 22 is The control circuit 4 determines that the ice is in a state of contact with the ice, that is, a full ice state in which the ice filling amount has reached a predetermined value, and sends an operation stop signal to the ice making machine 2 via the operation control signal line 17; A drive stop signal is sent to the ice making pump P1 via the drive control signal line 23 to stop the ice making operation.
[0032]
When the ice making operation is stopped, the ice making operation is restarted after a lapse of a predetermined time, for example, one hour by the timer control, and the ice making operation is repeated until the ice comes into contact with the full ice sensor again.
[0033]
In addition, the time until the resumption of the ice making operation described above is determined in advance from the relationship between the amount of heat of the ice stored in the ice heat storage tank and the amount of heat consumed on the load side when the ice is full, and the time required for the ice thawing is set in advance. In some cases, the ice making operation may be restarted by timer control after elapse of the time required for the ice melting.
[0034]
In addition, when there is a limit to the time at which ice making is performed, such as when performing ice making operation using nighttime electric power, the operation restart time is determined in advance in consideration of the relationship between the amount of heat of the stored ice and the time. However, the ice making operation may be restarted at that time.
[0035]
Furthermore, a lower limit sensor for detecting the lower limit of a preset ice storage height is provided in the ice heat storage tank, and has the same configuration as the full ice sensor. In some cases, the ice making operation is restarted when the temperature falls below the threshold.
[0036]
As described above, in the apparatus of the present invention, the control of the water level in the ice heat storage tank 1 and the filling amount of ice, that is, the control of the supply of make-up water and the control of the ice making operation are performed independently. Fluctuations in water level due to fluctuations and fluctuations in ice storage height due to fluctuations in water level are not considered.
[0037]
Therefore, even if water is discharged to the outside from the cold water supply path on the load side and the amount of water retained in the entire apparatus decreases, the operation control of the ice making machine is not affected at all, and a stable ice making operation is performed.
[0038]
In the above-described embodiment, ice water in which ice chips and water are mixed is generated by releasing the supercooled state of the water that has been supercooled in the ice making machine 2, and the ice water is supplied to the ice heat storage tank 1 by the ice supply pipe 6. The supercooled water is sent to the ice heat storage tank as it is, the supercooled water collides with the dispersion plate provided in the tank, and the supercooled state of the supercooled water is released by the impact when it hits the dispersion plate In some cases, ice water is generated.
[0039]
In some cases, an ice maker that produces cube-shaped ice or small-piece ice is provided above the ice storage tank 1, and the ice generated by the ice maker is dropped directly into the tank and supplied.
[0040]
Further, in the above-described embodiment, a temperature sensor is used as the full ice sensor 15 for detecting that the ice in the ice heat storage tank 1 has been stored to a predetermined height, and the ice comes into contact with the temperature sensing part of the sensor. Although it is configured to detect that the ice has reached a predetermined height based on a temperature change, this full ice sensor may be a touch sensor that is normally open but is closed by contact with ice. In addition, it emits a light beam from above toward the surface of the ice 22, detects the height of the ice by the intensity of the reflected light from the ice surface, and detects that the ice is full when the reflected light exceeds a predetermined intensity. A light-emitting element and a light-receiving element for receiving light from the light-emitting element are provided at a predetermined height in the ice storage tank, that is, at a predetermined full ice height, so that the ice is filled with ice. In the state where it has not reached the state of Reaches the light-receiving element, but when the ice reaches a predetermined full ice height, the light from the light-emitting element is blocked by the ice 22 and does not reach the light-receiving element. Proximity sensors may be used.
[0041]
Actions and effects of the present invention
According to the ice heat storage device according to the present invention, the amount of water and the amount of ice stored in the ice heat storage tank are individually monitored by a water level sensor and a full ice sensor, respectively, and based on a signal from the water level sensor. The control circuit controls the supply of make-up water, and the control circuit controls the ice making operation of the ice making machine based on the signal from the full ice sensor.
[0042]
Therefore, even when the amount of water held in the device decreases, such as when cold water is discharged in the cold water circulation path on the load side, the water level in the ice heat storage tank is always kept within a certain range, and the ice making operation is not performed. Stable operation is performed without being affected by fluctuations in water level.
[Brief description of the drawings]
FIG. 1 is a configuration diagram showing an embodiment of an apparatus according to the present invention.
FIG. 2 is an enlarged front view showing a specific example of a full ice sensor.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Ice heat storage tank 2 Ice machine 3 Load side heat exchanger 4 Control circuit 5 Ice making water pipe 6 Ice water supply pipe 7 Cold water outgoing pipe 8 Cold water return pipe 9 Water sprinkling pipe 10 Refill water pipe 11 Open / close valve 12 Water level sensor 13 Water level signal line 14 Open / close Control signal line 15 Full ice sensor 16 Temperature signal line 17 Operation control signal line 18, 19 Open / close valve 20 Drain branch pipe 21 Air release branch pipe 22 Ice 23 Drive control signal line P1 Ice making pump P2 Cold water pump S1, S2, S3 , S4 Liquid contact sensor

Claims (1)

An ice storage tank that stores water and ice, an ice machine that freezes water sent from the ice storage tank to generate ice, and supplies the ice to the ice storage tank. A cold water supply path for sending the water cooled by the ice stored in the ice storage side to the load side, and returning the water heat-exchanged on the load side to the ice heat storage tank again, and in the ice heat storage tank, A water level sensor for detecting a water level, and a full ice sensor for detecting whether or not the storage height of the ice stored in the tank has reached a preset full ice state height; Control the supply of water into the ice heat storage tank based on the signal from the ice storage tank so that the water level is maintained within a predetermined range, and when the ice making machine is performing the ice making operation, Shut down the ice maker by receiving a signal from the sensor indicating that the ice has reached the full ice level. A control circuit, the ice heat storage device the water level and ice of the ice thermal storage tank is configured to be individually controlled.

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