JP2002156145A - How to operate the ice storage unit - Google Patents

Abstract

(57) [Problem] To provide a refrigeration cycle operation in an ice heat storage unit without damaging an expensive evaporator for producing cold water.
To provide an operation method of an ice heat storage unit that can be stably performed. SOLUTION: An evaporator 3 for making ice or an evaporator 5 for producing cold water.
In the operation method of the ice heat storage unit, which is selectively used depending on the time zone and performs the refrigeration cycle operation, the cooling water inlet or outlet of the cold water producing water tank 12 provided with the cold water producing evaporator 5 is provided. A temperature sensor 9 is disposed in the vicinity, and when the temperature sensor 9 detects a temperature equal to or lower than the set temperature during the ice making operation, an alarm is issued or displayed, and the operation of the compressor 1 is further performed. Try to stop.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for operating an ice heat storage unit, and more particularly to a method for operating a refrigeration cycle in an ice heat storage unit stably without damaging an expensive evaporator for producing cold water. The present invention relates to a method for operating an ice storage unit.

[0002]

2. Description of the Related Art In Japan, due to the power supply,
2:00 to 8:00 the following day is set as a night time zone, a low-priced late-night charge is set, and surplus power at midnight can be used inexpensively, and power can be used in a time zone to which the late-night charge is applied. As described above, a time switch and the like are provided in an electric circuit for midnight electric power that is independent of a normal electric power circuit.

On the other hand, in an air-conditioning system or the like equipped with an ice heat storage unit, an ice-making operation that consumes a large amount of power is usually performed in the nighttime period from 22:00 to 8:00 the next day. The switching operation for switching between the solenoid valve and the expansion valve disposed in the refrigeration cycle operation circuit is performed according to the time period so that the cold water production operation is performed during the daytime period of 00:00.

FIG. 2 shows an example of an air conditioning system having the ice heat storage unit. This system includes an evaporator 3 for ice making provided in an ice heat storage water tank 4 or an evaporator 5 for cold water production provided in a water tank 12 for producing cold water, which passes through a condenser 2 from a compressor 1. Via a chilled water pump 10 between a refrigerant circulation circuit for selectively circulating a refrigerant and a load 11 such as an ice heat storage water tank 4 and / or a chilled water production water tank 12 and a fan coil unit of an air conditioner. And a chilled water circulation circuit in which chilled water is circulated.

[0005] In this system, the ice making evaporator 3 and the cold water evaporator 3 are used to selectively circulate the refrigerant in the refrigerant circulation circuit to either the ice making evaporator 3 or the cold water producing evaporator 5. Solenoid valves 6a, 6b and expansion valves 7a, 7b are provided in pairs on the refrigerant inlet side of the evaporator 5 for production, and chilled water is supplied directly to the chilled water circulation circuit via the chilled water producing water tank 12 to load 11 Or a mixing three-way valve 12 for selecting whether to return to the load 11 from the cold water production water tank 12 through the ice heat storage water tank 4 and to the refrigerant outlets of the ice making evaporator 3 and the cold water production evaporator 5. Temperature sensors 8a and 8 such as thermostats for detecting the refrigerant temperature
b is arranged.

[0006]

In the air conditioning system having the conventional ice heat storage unit, the solenoid valve 6a is opened during the night time, and the compressor 1 is operated by the compressor 1.
And the evaporator 3 for ice making provided in the ice heat storage water tank 4
A refrigerant circulation circuit is formed so that the refrigerant circulates through the evaporator 3. The refrigerant is cooled by being evaporated by the evaporator 3 for ice making, and is cooled on the outer surface of the evaporator 3 for ice making provided in the ice heat storage water tank 4. When the ice accumulates, the water stored in the ice heat storage water tank 4 is gradually frozen. During the ice making operation, the electromagnetic valve 6b communicating with the evaporator 5 for producing cold water is closed, so that the refrigerant does not flow into the evaporator 5 for producing cold water.

However, for example, when the refrigerant leaks due to failure of the solenoid valve 6b disposed on the refrigerant inlet side of the evaporator 5 for producing cold water, the refrigerant flows into the evaporator 5 for producing cold water. . At this time, when the state in which the refrigerant evaporates in the evaporator 5 for cold water production continues for a certain period of time or more by the solenoid valve 6b serving as a throttle mechanism, the water tank 12 for cold water production in which the evaporator 5 for cold water production is disposed When the water is cooled and the operation is further continued, the water in the cold water producing water tank 12 is not circulated, so that it is cooled and becomes ice, and finally the water in the cold water producing water tank 12 freezes, and its volume Due to the expansion, the cold water producing evaporator 5 disposed in the cold water producing water tank 12 is damaged.

In order to prevent this from happening, a temperature sensor 8b is provided on the refrigerant outlet side of the evaporator 5 for producing cold water.
The temperature of the refrigerant at the position of the temperature sensor 8b is different from that of the water in the water tank 12 for producing cold water. Since the temperature of the refrigerant after the heat exchange is performed between the compressor 1 and the compressor 1, the leakage of the refrigerant cannot be accurately detected.
There is a problem that even if the operation is stopped, damage to the evaporator 5 for producing cold water cannot be reliably prevented.

The present invention has been made in view of the above-mentioned problems of an air conditioning system having the conventional ice heat storage unit, and has been developed to stabilize the refrigeration cycle operation in the ice heat storage unit without damaging an expensive evaporator for producing cold water. It is an object of the present invention to provide an operation method of an ice heat storage unit which can be performed by performing the above operation.

[0010]

In order to achieve the above object, an operation method of an ice heat storage unit according to the present invention is to selectively use one of an evaporator for ice making and an evaporator for cold water production according to a time zone. In the operation method of the ice heat storage unit that performs the cycle operation, a temperature sensor is disposed at a position near an inlet or an outlet of the chilled water in the chilled water production water tank in which the chilled water production evaporator is disposed, and during the ice making operation, When the temperature sensor detects a temperature equal to or lower than a set temperature, an alarm is issued or displayed, and the operation of the compressor is stopped.

The operation method of the ice heat storage unit is as follows. A temperature sensor is provided at a position near an inlet or an outlet of cold water in a water tank for cold water production in which an evaporator for cold water production is provided.
When the temperature sensor detects a temperature equal to or lower than the set temperature, it issues an alarm or displays the alarm, and further stops the operation of the compressor, so that the refrigerant inlet side of the evaporator for producing cold water. Even if the refrigerant leaks due to failure of the solenoid valve arranged in the chiller and the refrigerant flows into the evaporator for producing cold water, this can be quickly detected and the operation of the compressor can be stopped. In addition, it is possible to prevent the expensive evaporator for producing cold water from being damaged.

In this case, during the cold water production operation, the temperature sensor detects the temperature of the circulating cold water, and performs the capacity control operation of the compressor in accordance with the detected temperature, or stops the compressor and stops the cold water. Can be controlled such that the temperature does not fall below the set temperature.

As a result, water in the cold water producing water tank 12 freezes during the cold water producing operation, and the volume expansion causes damage to the expensive cold water producing evaporator 5 disposed in the cold water producing water tank 12. It is possible to prevent the feeding of the compressor 1 beforehand, and to operate the compressor 1 efficiently and stably.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of a method for operating an ice heat storage unit according to the present invention will be described with reference to the drawings.

FIG. 1 shows an example of an air conditioning system provided with an ice heat storage unit for implementing the method for operating the ice heat storage unit of the present invention. In the figure, 1 is a compressor, 2 is a condenser, 3 is an evaporator for ice making provided in an ice heat storage water tank 4, and 5 is an evaporator for cold water production provided in a water tank 12 for producing cold water.
An air-conditioning system including an ice heat storage unit is provided with an ice evaporator 3 disposed in an ice heat storage water tank 4 or a cold water production water tank 12 disposed in a cold water production water tank 12 through a condenser 2 from a compressor 1. A refrigerant circulation circuit A in which the refrigerant is selectively circulated to any one of the evaporators 5, an ice heat storage water tank 4 and / or a cold water production water tank 12, and a load 11 such as a fan coil unit of an air conditioner. And a chilled water circulation circuit B through which chilled water is circulated via a chilled water pump 10.

In the refrigerant circuit A, the ice making evaporator 3 and the chilled water producing evaporator 3 are provided to selectively circulate the refrigerant to either the ice making evaporator 3 or the cold water producing evaporator 5. The solenoid valves 6a and 6b and the expansion valves 7a and 7b are arranged in pairs on the refrigerant inlet side of No. 5.

In the chilled water circulation circuit B, mixing for selecting whether to return the chilled water directly to the load 11 through the chilled water production tank 12 or to return the chilled water from the chilled water production tank 12 to the load 11 through the ice heat storage water tank 4 is selected. A three-way valve 12 is provided, and a temperature sensor 8 such as a thermostat for detecting a refrigerant temperature at a refrigerant outlet of the evaporator 3 for making ice and the evaporator 5 for producing cold water.
a and 8b are arranged.

Further, in this embodiment, the temperature of the thermostat or the like is connected to a position near the outlet of the chilled water of the chilled water tub 12 in which the chilled water manufacturing evaporator 12 is disposed, specifically, the piping of the chilled water circulation circuit B. The sensor 9 is provided.

In this embodiment, the operation set temperature of the temperature sensor 9 is changed between the ice making operation in the night time zone and the cold water production operation in the day time zone.

During the ice making operation during the night time, the operation set temperature of the temperature sensor 9 is not particularly limited, but is set to, for example, 2 ° C., and the temperature sensor 9 is set to a temperature lower than the set temperature. When the temperature is detected, an alarm is issued or displayed, and the operation of the compressor 1 is stopped. In this case, an alarm is issued,
The set temperature for displaying this and the set temperature for stopping the operation of the compressor 1 may be set to the same temperature or different temperatures. As a result, for example, even if the solenoid valve 6b disposed on the refrigerant inlet side of the cold water production evaporator 5 breaks down and the refrigerant leaks, the water in the cold water production water tank 12 freezes, and Due to the volume expansion, it is possible to prevent the expensive evaporator 5 for cold water production provided in the water tank 12 for cold water production from being damaged, and to be in charge of maintenance by an alarm that is issued or displayed. Can quickly recover from the failure of the solenoid valve 6b, etc., and stably perform the refrigeration cycle operation in the ice heat storage unit.

Further, even during the cold water production operation in the daytime, the temperature sensor 9 detects the temperature of the circulating cold water, and performs the capacity control operation of the compressor 1 in accordance with the detected temperature.
Alternatively, it is possible to stop the compressor 1 and control the temperature of the cold water so as not to be lower than the set temperature.
In addition, when the temperature sensor 9 operates during the cold water production operation, the capacity control operation of the compressor 1 is performed, and when the temperature of the cold water decreases, the compressor 1 is stopped and the temperature of the cold water is reduced. It controls so that it does not become lower than the set temperature, but in this case, usually does not issue an alarm or display this, and if the temperature of the cold water rises to the set temperature,
The compressor 1 is operated and controlled to perform the cold water production operation. As a result, the water in the cold water production water tank 12 freezes during the cold water production operation, and damages the expensive cold water production evaporator 5 disposed in the cold water production water tank 12 due to its volume expansion. It is possible to prevent the problem beforehand and to operate the compressor 1 efficiently and stably.

Although the operation method of the ice heat storage unit of the present invention has been described based on the embodiments, the present invention is not limited to the configuration described in the above embodiments.
For example, instead of disposing a temperature sensor 9 such as a thermostat in the pipe of the chilled water circulation circuit B near the outlet of the chilled water for the chilled water production water tank 12, a position near the inlet of the chilled water of the chilled water production water tank 12 may be used. For example, a temperature sensor such as a thermostat can be provided in the piping of the chilled water circulation circuit B, and the configuration thereof can be appropriately changed without departing from the gist thereof.

[0023]

According to the method for operating the ice heat storage unit of the present invention, a temperature sensor is provided at a position near an inlet or an outlet of cold water in a water tank for cold water production in which an evaporator for cold water production is provided, and the ice making operation is performed. In the meantime, when the temperature sensor detects a temperature equal to or lower than the set temperature, it issues an alarm or displays this and further stops the operation of the compressor, so that the evaporator for producing cold water is If the solenoid valve disposed on the refrigerant inlet side breaks down and the refrigerant leaks and the refrigerant flows into the evaporator for producing cold water, this is quickly detected and the operation of the compressor is stopped. be able to. Thereby, it is possible to prevent damage to the expensive evaporator for producing cold water, and it is possible to quickly recover from a malfunction of the solenoid valve and stably perform the refrigeration cycle operation in the ice heat storage unit. it can.

Further, during the cold water production operation, the temperature sensor
Detect the temperature of the circulating cold water, and perform the capacity control operation of the compressor or stop the compressor according to the detected temperature,
By controlling the temperature of the chilled water so as not to be lower than the set temperature, the water in the chilled water manufacturing water tank freezes during the chilled water manufacturing operation, and is arranged in the chilled water manufacturing water tank for volume expansion. Damage to the expensive cold water producing evaporator 5 can be prevented beforehand, and the compressor can be operated efficiently and stably.

[Brief description of the drawings]

FIG. 1 is a configuration diagram illustrating an example of an air conditioning system including an ice heat storage unit that implements an operation method of an ice heat storage unit according to the present invention.

FIG. 2 is a configuration diagram of an air conditioning system including a conventional ice heat storage unit.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Compressor 2 Condenser 3 Ice evaporator 4 Ice heat storage water tank 5 Cold water production evaporator 6a, 6b Solenoid valve 7a, 7b Expansion valve 8a, 8b Temperature sensor 9 Temperature sensor 10 Cold water pump 11 Load 12 Cold water production water tank

Claims (2)

[Claims] 1. A method for operating an ice storage unit in which an ice making evaporator or a chilled water producing evaporator is selectively used according to a time zone to perform a refrigeration cycle operation. A temperature sensor is disposed in the vicinity of the inlet or outlet of the chilled water in the installed chilled water production tank, and during the ice making operation, when the temperature sensor detects a temperature lower than the set temperature, an alarm is issued, or An operation method of the ice heat storage unit, wherein the operation is displayed and the operation of the compressor is stopped. 2. A chilled water production operation, a temperature sensor detects the temperature of the circulating chilled water, and performs a capacity control operation of the compressor in accordance with the detected temperature, or stops the compressor to stop the chilled water temperature. 2. The method for operating an ice heat storage unit according to claim 1, wherein the temperature is controlled so as not to become lower than a set temperature.