JP3304010B2 - Ice storage refrigerator and operation method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an ice storage refrigerator, and more particularly to an economical ice storage refrigerator that can be effectively used for a building cooling system.

[0002]

2. Description of the Related Art An ice regenerative refrigerator has been developed as a cooling system that uses economical nighttime electric power, and is used as an energy-saving and space-saving building cooling system. In the conventional ice regenerative refrigerator, it is good to perform the heat storage operation and the cooling operation independently. However, in the case of performing the cooling operation while performing the heat storage operation, no consideration is given to freezing the cold water in the water heat exchanger.

[0003]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and to cope with the diversification of current building cooling, an ice storage type refrigerator capable of performing cooling operation while performing heat storage operation. It is an object to provide the driving method.

[0004]

According to the present invention, there is provided a refrigerator having a refrigerator, an ice heat storage tank, a water heat exchanger, a pump, a control valve, and a piping system for connecting them. The brine is cooled, the water in the ice heat storage tank is frozen and heat is stored in the brine.At the time of heat radiation, the brine is cooled by the heat of melting of ice in the ice heat storage tank, and the brine is transferred to the water heat exchanger. In the ice regenerative refrigerator that guides and cools the cold water to take out the cooling capacity, a brine outlet temperature sensor is provided at a brine outlet of the water heat exchanger, and a branch is made from a brine loop that circulates through the refrigerator and the ice heat storage tank. After sending brine to the water heat exchanger and leaving the water heat exchanger, a line is provided to return to the loop of the brine circulating through the refrigerator and ice heat storage tank. A flow control valve to adjust the brine flow Only, as an input signal of the outlet temperature sensor issues an output signal to the brine flow rate regulating valve, is provided with a controller for controlling the brine outlet temperature.

Further, the present invention has a refrigerator, an ice heat storage tank, a water heat exchanger, a pump, a control valve, and a piping system for connecting them, and the brine is cooled by the refrigerator, and the brine is used to cool the ice heat storage tank. Ice heat is stored by freezing water, and at the time of heat radiation, the brine is cooled by the heat of melting of ice in an ice heat storage tank, the brine is guided to a water heat exchanger, and cold water is cooled to obtain cooling capacity. In the refrigerator, a brine outlet temperature sensor is provided at a brine outlet of the water heat exchanger, and the brine branches from a brine line that exits the heat storage tank and returns to the refrigerator to send brine to the water heat exchanger. Along with
In this line or in a line after the water heat exchanger following this line, a flow rate control valve for adjusting the brine flow rate to the water heat exchanger is provided, and the signal of the outlet temperature sensor is used as an input,
A controller for outputting an output signal to the brine flow control valve and controlling the brine outlet temperature is provided.

In the ice regenerative refrigerator, the water heat exchanger is also provided with a brine inlet temperature sensor at the brine inlet, and receives a signal from the brine inlet / outlet temperature sensor as input and outputs an output signal to a brine flow control valve. In addition, a controller for controlling the brine temperature is provided, or the water heat exchanger is further provided with a brine inlet / outlet and a temperature sensor for chilled water measurement, and the brine inlet / outlet temperature sensor and the chilled water temperature sensor are used as inputs to receive the brine. An output signal is output to the flow control valve to provide a controller for controlling the chilled water temperature and the brine temperature.

According to the present invention, in the method for operating an ice regenerative refrigerator, when the cold water is cooled by the water heat exchanger during the heat storage operation for forming ice in the heat storage tank, the temperature sensor may include:
(1) If the water heat exchanger is installed only at the brine outlet,
So that the temperature at the brine outlet exceeds at least 0 ° C
Preferably, the temperature is controlled so as to be 2 ° C. or more. (2) In the case where it is provided at the brine inlet / outlet, the average temperature of the brine inlet temperature and the brine outlet temperature is at least 0 ° C., preferably 1 ° C. or more. And control as follows.

When temperature sensors are provided at the brine inlet and outlet of the water heat exchanger and the chilled water, the brine flow rate is adjusted so that the chilled water temperature of the water heat exchanger becomes the target temperature.
When the brine inlet temperature is below the freezing point, the brine outlet temperature is controlled so as to be at least a temperature above the freezing point, or the average temperature of the brine inlet and outlet exceeds at least 0 ° C. in preference to the cold water temperature control. It is controlled and operated.

[0009] The structure of the heat storage tank used in the present invention is such that a heat exchanger is provided in the heat storage tank, water in the heat storage tank (there is no forced flow, and the whole is stationary), The supplied brine is in contact with the heat transfer surface of the heat exchanger. Then, when storing heat, the water is frozen with brine, and when dissipating heat, the brine is cooled with ice.

[0010]

In the ice regenerative refrigerator, the brine cooled by the refrigerator during the heat storage operation is about -4 ° C. When the water heat exchanger is cooled by this brine, that is, when the heat exchange is performed with the cold water, the cold water freezes. May destroy the water heat exchanger. In the present invention, the brine leading to the water heat exchanger is the brine after exiting the heat storage tank, and the brine temperature is monitored, and the water heat exchanger is controlled to reliably transfer heat from the brine to the water. . Even if the brine inlet temperature to the water heat exchanger is a minus temperature (below the freezing point), if the brine outlet temperature is controlled to be a plus temperature (above the freezing point), the water inside the water heat exchanger will have more than freezing water. Is guaranteed to exist. Also,
If the average temperature is positive, local freezing in the heat exchanger can also be reliably prevented.

The reason for detecting the temperature on the brine side is that the brine is not frozen and the temperature can be easily detected. On the other hand, the temperature detection on the chilled water side does not allow the chilled water to flow when the chilled water freezes inside. This is because the temperature may not be frozen in some parts, and freezing cannot be monitored. If the cold water freezes inside, the flow of the cold water stops, the brine temperature does not rise, and the inlet and outlet are at minus temperatures, so that the freezing is determined. That is, the brine temperature is monitored, and if the brine outlet temperature is 0 ° C. or higher, it can be determined that the cold water is not frozen inside. (The brine temperature is monitored. If the brine temperature is different at the entrance and exit, it can be determined that cold water is flowing. If the exit temperature is 0 ° C or more, it can be determined by one point measurement.)

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be specifically described with reference to the drawings, but the present invention is not limited to these. Embodiment 1 FIG. 1 is a schematic configuration diagram showing an example of an ice storage refrigerator according to the present invention. In FIG. 1, 1 is a refrigerator, 2 is an ice heat storage tank,
3 is a water heat exchanger, 4 is a pump, 5 is a control valve, 7, 8, 9
Is a temperature sensor, 10 is a controller, 11 is cold water, and 12 is a bypass pipe. Temperature sensors 7, 8,
The temperature is detected at 9 and the controller 10 controls the control valve 5 to control freezing.

The operation using the ice storage refrigerator of FIG. 1 will be described. In the case of the heat storage operation, the refrigerator 1 is operated,
For example, the water is cooled to about −4 ° C. by the refrigerator 1 and sent to the heat storage tank 2 to freeze the water in the ice heat storage tank 2. In this state, if it is desired to take out cold water from the water heat exchanger 3, the valve 5
Is adjusted to guide the brine to the water heat exchanger 3 to cool the cold water 11. If the brine outlet temperature 7 to the water heat exchanger 3 is higher than the freezing point, there is no fear of freezing.

When controlling the chilled water temperature to the target temperature, the flow rate is adjusted by the valve 5. If the brine inlet temperature 8 to the water heat exchanger 3 is lower than the freezing point, there is a risk of freezing, and even if the cold water temperature 9 is controlled to the target temperature, priority is given to:
The flow rate is adjusted by the valve 5 so that the brine outlet temperature 7 exceeds the freezing point. When the refrigerator 1 and the heat storage tank 2 are used together in the heat dissipation operation, the refrigerator 1 is controlled so that the brine outlet temperature of the refrigerator 1 becomes the target temperature, and the brine valve is controlled so that the chilled water outlet temperature 9 becomes the target temperature. Adjust 5

In the case of the single operation of the heat storage tank, the brine valve 5 is adjusted so that the chilled water outlet temperature 9 becomes the target temperature. In this case, the brine temperature is higher than the freezing point, and there is no fear of freezing. When the refrigerator alone is required, a valve 6 and a pipe 12 as shown by a broken line are provided so that the heat storage tank can be bypassed.
Further, as shown in FIG. 3, even when the brine is sent from the control valve 5 to the heat storage tank 2, the same operation as in FIG. 1 can be performed.

Embodiment 2 FIG. 2 shows a schematic configuration diagram of another example of the ice storage refrigerator of the present invention. In FIG. 2, 1 is a refrigerator, 2 is an ice heat storage tank, 3
a and 3b are water heat exchangers, 4a and 4b are pumps, 5 is a control valve, 6 is a switching valve, 7, 8, and 9 are temperature sensors, and 10 is a controller. In FIG. 2, 1-5-3a-4a-1 of the refrigerator loop and 2-4b of the heat storage tank loop.
-3b-6-2 are formed, and in the cooling operation during operation of the refrigerator, the respective temperatures are detected by the temperature sensors 7, 8, 9 and the controller 10 controls the control valves 5, 6, Is adjusted to prevent freezing of cold water.

The operation of the refrigerator shown in FIG. 2 will be described. In the heat storage operation, the pump 4a of the refrigerator loop is operated, and the three-way valve 5 causes the brine to flow from the refrigerator 1 to the heat storage tank loop, while the brine does not flow back to the water heat exchanger 3b in the heat storage tank loop. The valve 6 is closed. A check valve may be used instead of the two-way valve 6. In this state, the refrigerator 1 is operated, for example, cooled to about −4 ° C. by the refrigerator 1 and sent out to the heat storage tank 2 to freeze the water in the ice heat storage tank 2.

In the case of the heat storage / cooling operation, the refrigerator 4 is operated by operating the pump 4a of the refrigerator loop and the three-way valve 5 to flow the brine from the refrigerator 1 to the heat storage tank loop. In step 1, the mixture is cooled to about -4 ° C. and sent to the heat storage tank 2 to freeze the water in the ice storage tank 2. On the other hand, the pump 4b of the heat storage tank loop is also operated, and the brine coming out of the heat storage tank 2 (from about −4 ° C. at the inlet to about 0 ° C. at the outlet) is transferred to the water heat exchanger 3b. Run down to cool the cold water. At this time, the cold water temperature 9 can be controlled by adjusting the brine flow rate with the two-way valve 6. When the brine temperature 8 decreases, the flow rate of the brine may be limited to give priority to the chilled water temperature control to prevent the chilled water 11 from freezing.

In the heat dissipation operation, the refrigerator loop and the heat storage tank loop are separated by the three-way valve 5, the pump 4b of the heat storage tank loop is operated, the two-way valve 6 is opened, and the water heat exchanger 3 is opened.
Demonstrate the cooling capacity from b. In the water heat exchanger 3b, the brine is warmed by cold water, and the brine is cooled by ice. At this time, the refrigerator loop may operate the refrigerator 1 and the pump 4a to exhibit the refrigeration capacity via the water heat exchanger 3a.

When the refrigerator loop is stopped, the heat storage tank alone is operated, and when the refrigerator loop is also operated, the heat storage tank / refrigerator combined operation is performed. In the case of the refrigerator alone operation, the refrigerator loop and the heat storage tank loop are separated from each other by the three-way valve 5, and the refrigerator 1 and the pump 4a of the refrigerator loop are operated to exhibit the cooling capacity from the water heat exchanger 3a. . The brine is cooled by the refrigerator, and the cold water is cooled by the brine in the water heat exchanger 3a. At this time, the pump 4b of the heat storage tank loop is stopped.

[0021]

According to the present invention, since the cold water of the water heat exchanger can be prevented from freezing, the cooling operation can be performed while the heat storage operation is being performed, and it can sufficiently cope with various types of cooling such as OA buildings. The result is an energy-saving and economical ice storage refrigerator.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing an example of an ice storage refrigerator according to the present invention.

FIG. 2 is a schematic configuration diagram showing another example of the ice storage refrigerator of the present invention.

FIG. 3 is a schematic configuration diagram showing another example of the ice storage refrigerator of the present invention.

[Explanation of symbols]

1: Refrigerator, 2: Ice storage tank, 3, 3a, 3b: Water heat exchanger, 4, 4a, 4b: Pump, 5: Control valve, 6: Switching valve, 7, 8, 9: Temperature sensor, 10 : Controller, 11: Cold water, 12: Bypass pipe,

Continuation of the front page (56) References JP-A-2-89946 (JP, A) JP-A-5-322274 (JP, A) JP-A-2-219959 (JP, A) JP-A-53-49356 (JP) JP-A-2-192540 (JP, A) JP-A-6-249474 (JP, A) JP-A-3-63432 (JP, A) JP-A-1-66531 (JP, U) (58) Field surveyed (Int. Cl. ⁷ , DB name) F24F 5/00 F24F 11/02 F25C 1/00

Claims (5)

(57) [Claims] 1. A refrigerator, an ice storage tank, a water heat exchanger, a pump, a control valve, and a piping system for connecting them, the brine is cooled by the refrigerator, and the water in the ice storage tank is frozen by the brine. An ice storage type refrigerator that cools the brine by the heat of melting of ice in an ice storage tank, guides the brine to a water heat exchanger, cools chilled water, and takes out cooling capacity during heat dissipation. At the brine outlet of the water heat exchanger, a brine outlet temperature sensor is provided, a refrigerator, a branch from a brine loop circulating in the ice heat storage tank, and brine sent to the water heat exchanger, and the water heat exchanger is After exiting , the refrigerator, a line returning to the brine loop circulating through the ice heat storage tank is provided, and in this line, a flow rate control valve for controlling the brine flow rate to the water heat exchanger is provided, and the outlet temperature sensor is provided. The signal is used as an input An ice storage refrigerator having a controller for outputting an output signal to a flow control valve and controlling a brine outlet temperature. 2. A refrigerator, an ice heat storage tank, a water heat exchanger, a pump, a control valve, and a piping system for connecting them, and the brine is cooled by the refrigerator, and the water in the ice heat storage tank is frozen by the brine. An ice storage type refrigerator that cools the brine by the heat of melting of ice in an ice storage tank, guides the brine to a water heat exchanger, cools chilled water, and takes out cooling capacity during heat dissipation. At the brine outlet of the water heat exchanger, a brine outlet temperature sensor is provided, and a line is provided for sending brine to the water heat exchanger by branching from a brine line that returns from the heat storage tank and returns to the refrigerator. In this line or in a line after the water heat exchanger following this line, a flow control valve for adjusting the brine flow rate to the water heat exchanger is provided, and the signal of the outlet temperature sensor is input, and the brine flow control valve is used. Output signal And a controller for controlling the brine outlet temperature. 3. A brine inlet temperature sensor is also provided in the water heat exchanger at a brine inlet portion, and a signal from the brine inlet / outlet temperature sensor is input, and an output signal is output to a brine flow control valve. The ice regenerative refrigerator according to claim 1 or 2, further comprising a controller for controlling the ice regenerative refrigerator. 4. The water heat exchanger is provided with a temperature sensor for chilled water measurement together with the brine inlet / outlet, and receives an output signal from the brine inlet / outlet temperature sensor and the chilled water temperature sensor and outputs an output signal to a brine flow control valve. 4. An ice regenerative refrigerator according to claim 3, further comprising a controller for controlling the temperature of the cold water and the temperature of the brine. 5. The method for operating an ice regenerative refrigerator according to claim 1 or 2, wherein when the cold water is cooled by the water heat exchanger during the heat storage operation for forming ice in the heat storage tank. Controlling the brine outlet temperature to at least exceed 0 ° C.