CN113819682B

CN113819682B - Refrigeration system and control method thereof

Info

Publication number: CN113819682B
Application number: CN202111064548.9A
Authority: CN
Inventors: 刘帅; 许文明
Original assignee: Qingdao Haier Air Conditioner Gen Corp Ltd; Qingdao Haier Air Conditioning Electric Co Ltd; Haier Smart Home Co Ltd
Current assignee: Qingdao Haier Air Conditioner Gen Corp Ltd; Qingdao Haier Air Conditioning Electric Co Ltd; Haier Smart Home Co Ltd
Priority date: 2021-09-10
Filing date: 2021-09-10
Publication date: 2023-03-21
Anticipated expiration: 2041-09-10
Also published as: CN113819682A

Abstract

The invention relates to the technical field of refrigeration equipment, and provides a refrigeration system and a control method thereof. The refrigerating system comprises a refrigerating device, a cold storage device, a heat exchanger, a refrigerator and a controller; the refrigerating device comprises an accommodating cavity for accommodating a heat exchange medium, and a liquid inlet and a liquid outlet of the accommodating cavity are respectively communicated with the cold storage cavity and the liquid return cavity; the heat exchanger is provided with a first medium channel and a second medium channel, the first medium channel is connected in parallel with two ends of an evaporation coil of the refrigerator, and a liquid inlet and a liquid outlet of the second medium channel are respectively communicated with the liquid return cavity and the cold storage cavity; a second stop valve and a second circulating pump are arranged on a communication pipeline between the cold storage device and the second medium channel; and a second temperature sensor and a liquid level sensor which are respectively in communication connection with the controller are arranged in the cold storage cavity. The cold storage cavity is positioned above the liquid return cavity, the bottom of the cold storage cavity is provided with a water outlet, the liquid return cavity is provided with a water inlet, and a communication pipeline between the water outlet and the water inlet is provided with a third stop valve.

Description

Refrigeration system and control method thereof

Technical Field

The invention relates to the technical field of refrigeration equipment, in particular to a refrigeration system and a control method thereof.

Background

At present, refrigerating devices become essential electric appliances in life, such as refrigerated cabinets for refrigerating food, air conditioners or air conditioning fans for adjusting indoor temperature, and the like. Among them, the refrigerator is generally provided with a compressor, and the air conditioner is also provided with an outdoor unit having the compressor, resulting in high product costs. The air-conditioning fan stores ice water in a water tank or places an ice box, and then conveys water to the water-absorbing fiber evaporator through a water pump. The wind blown out by the fan passes through the water absorption fiber evaporator, and takes away the heat of the air by utilizing the principle of water evaporation and heat absorption, thereby achieving the effect of blowing out cool wind. Although the air conditioner fan does not need a compressor, the cost of the product is reduced, in order to ensure that the air conditioner fan can continuously refrigerate, ice water or an ice box needs to be frequently replaced, and the use is inconvenient.

Disclosure of Invention

The invention provides a refrigerating system and a control method thereof, which are used for solving the problems that a refrigerating device in the prior art is high in cost or cannot continuously refrigerate.

The invention provides a refrigerating system which comprises a refrigerating device, a cold storage device, a heat exchanger, a refrigerator and a controller;

the cold storage device is provided with a cold storage cavity and a liquid return cavity; the refrigerating device comprises an accommodating cavity for accommodating a heat exchange medium, a liquid inlet of the accommodating cavity is communicated with the cold storage cavity, and a liquid outlet of the accommodating cavity is communicated with the liquid return cavity; the heat exchanger is provided with a first medium channel and a second medium channel, the first medium channel is connected to two ends of an evaporation coil of the refrigerator in parallel, a liquid inlet of the second medium channel is communicated with the liquid return cavity, and a liquid outlet of the second medium channel is communicated with the cold storage cavity;

a second stop valve and a second circulating pump are arranged on a communication pipeline between the cold storage device and the second medium channel; a second temperature sensor and a liquid level sensor are arranged in the cold storage cavity and are respectively used for detecting the cold storage temperature and the liquid level height of the heat exchange medium in the cold storage cavity, and the second temperature sensor and the liquid level sensor are respectively in communication connection with the controller; the cold storage cavity is positioned above the liquid return cavity, a water outlet is formed in the bottom of the cold storage cavity, a water inlet is formed in the liquid return cavity, and a third stop valve is arranged on a communication pipeline between the water outlet and the water inlet.

According to the refrigeration system provided by the invention, the cold storage device comprises a box body, and a vacuum heat insulation layer is arranged in the box body to divide the box body into the cold storage cavity and the liquid return cavity.

According to the refrigeration system provided by the invention, a fourth stop valve is arranged on the liquid inlet pipeline or the liquid outlet pipeline communicated with the first medium channel.

The invention also provides a control method of any one of the refrigeration systems, which comprises the following steps:

acquiring the working frequency of a compressor in the refrigerator according to a preset time interval;

determining that the working frequency is less than a set working frequency, and acquiring the cold storage temperature and the liquid level height of the heat exchange medium in the cold storage cavity;

and controlling the second stop valve, the third stop valve and the second circulating pump to be opened and closed according to the cold storage temperature and the liquid level height.

According to a control method of a refrigeration system provided by the present invention, the controlling of opening and closing of the second stop valve, the third stop valve, and the second circulation pump according to the cold storage temperature and the liquid level includes:

and determining that the cold storage temperature is less than or equal to a second set temperature and the liquid level height is less than or equal to a second set height, controlling the third stop valve to be closed, and controlling the second stop valve and the second circulating pump to be opened.

According to the control method of the refrigeration system provided by the invention, the method further comprises the following steps:

acquiring current time according to a preset time interval;

determining that the current time is within a preset valley power time period, and then taking the second set height as a first set value; otherwise, the second set height is taken as a second set value; wherein the first set value is larger than the second set value.

determining that the cold storage temperature is higher than a second set temperature and the liquid level height is higher than 0, and controlling the third stop valve to open;

after the third stop valve is controlled to be opened, if the liquid level is determined to be =0, the third stop valve is controlled to be closed, and the second stop valve and the second circulating pump are controlled to be opened.

According to the control method of the refrigeration system provided by the invention, after the controlling the second stop valve and the second circulation pump to be opened, the method further comprises the following steps:

and if any condition that the liquid level height is larger than or equal to a third set height and the working frequency is not smaller than the set working frequency is determined, controlling the second stop valve and the second circulating pump to be closed.

acquiring current time according to a preset time interval;

determining that the current time is within a preset valley power time period, and then taking the third set height as a third set value; otherwise, the third set height is set as a fourth set value; wherein the third set value > the fourth set value.

According to the control method of the refrigerating system, provided by the invention, if the working frequency is determined to be less than the set working frequency, the opening of a fourth stop valve is controlled; otherwise, controlling the fourth stop valve to close.

According to the refrigeration system and the control method thereof, the refrigeration system of the refrigerator is used for cooling the heat exchange medium flowing through the heat exchanger and then conveying the cooled heat exchange medium to the cold storage device for storage by arranging the cold storage device, the heat exchanger and the refrigerator, so that the refrigeration system is used for refrigeration of the refrigeration device, a compressor is not required to be additionally and independently configured for the refrigeration device, the cost of the refrigeration device is saved, and continuous refrigeration of the refrigeration device can be realized. When the refrigerating device is an air-conditioning fan, ice water or an ice box does not need to be replaced repeatedly. The refrigerating device, the cold storage device and the heat exchanger form a closed-loop circulating system by arranging the cold storage cavity and the liquid return cavity in the cold storage device, so that energy is saved. The opening and closing of the second stop valve, the third stop valve and the second circulating pump can be controlled according to the cold storage temperature and the liquid level height in the cold storage cavity, so that the cold storage control is performed on the cold storage device. The cold storage efficiency of the cold storage device is improved while the cold storage device is ensured to store enough cold to meet the requirement of continuous refrigeration of the refrigeration device.

Drawings

In order to more clearly illustrate the present invention or the technical solutions in the prior art, the drawings used in the embodiments or the description of the prior art will be briefly introduced below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and other drawings can be obtained by those skilled in the art without creative efforts.

FIG. 1 is a schematic diagram of a refrigeration system provided by the present invention;

FIG. 2 is a schematic flow diagram of a method of controlling a refrigeration system provided by the present invention;

reference numerals:

1. a refrigeration device; 11. A refrigeration module; 111. A cold storage tube;

112. an accommodating cavity; 12. A heat exchange pipe; 13. A fifth stop valve;

14. a flow regulating valve; 15. A water pan; 2. A cold storage device;

21. a cold storage cavity; 22. A liquid return cavity; 23. A box body;

3. a heat exchanger; 4. A refrigerator; 41. An evaporating coil;

42. a condenser coil; 43. A compressor; 44. An electronic expansion valve;

51. a first shut-off valve; 52. A second stop valve; 53. A third stop valve;

54. a fourth stop valve; 61. A first circulation pump; 62. And a second circulation pump.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings, and it is obvious that the described embodiments are some, but not all embodiments of the present invention. All other embodiments, which can be obtained by a person skilled in the art without making any creative effort based on the embodiments in the present invention, belong to the protection scope of the present invention.

In the description of the embodiments of the present invention, it should be noted that the terms "first", "second", "third", "fourth" and "fifth" are used for the sake of clarity in describing the numbering of the product parts and do not represent any substantial difference, unless explicitly stated or limited otherwise. Specific meanings of the above terms in the embodiments of the present invention can be understood by those of ordinary skill in the art according to specific situations. In addition, "and/or" in the specification and claims means at least one of connected objects, a character "/" generally means that a preceding and succeeding related objects are in an "or" relationship.

In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; they may be directly connected, indirectly connected through intervening media, or may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

The invention provides a refrigeration system, and fig. 1 is a schematic structural diagram of the refrigeration system provided by the invention. The refrigeration system provided by the invention comprises a refrigeration device 1, a heat exchanger 3, a refrigerator 4 and a controller. The cold storage device 2 is provided with a cold storage cavity 21 and a liquid return cavity 22. The refrigerating device 1 comprises an accommodating cavity 112 for accommodating a heat exchange medium, an inlet of the accommodating cavity 112 is communicated with the cold storage cavity 21, and an outlet of the accommodating cavity 112 is communicated with the liquid return cavity 22. The heat exchanger 3 is provided with a first medium channel and a second medium channel, the first medium channel is connected in parallel with two ends of an evaporation coil 41 of the refrigerator 4, a liquid inlet of the second medium channel is communicated with the liquid return cavity 22, and a liquid outlet of the second medium channel is communicated with the cold storage cavity 21. The refrigerant in the first medium channel can exchange heat with the heat exchange medium in the second medium channel.

In some embodiments of the present invention, a second stop valve 52 and a second circulation pump 62 are disposed on a connection pipeline between the cold storage device 2 and the second medium passage. And a second temperature sensor and a liquid level sensor are arranged in the cold storage cavity 21 and are respectively used for detecting the cold storage temperature and the liquid level height of the heat exchange medium in the cold storage cavity 21. The second temperature sensor and the liquid level sensor are respectively in communication connection with the controller.

The second circulation pump 62 is used for driving the heat exchange medium to flow into the cold storage device 2. The controller may be configured to output the cold storage temperature Tc or the liquid level Hc so that the user opens or closes the second cutoff valve 52 and the second circulation pump 62 according to the cold storage temperature Tc or the liquid level Hc. Or, the controller is in communication connection with the second stop valve 52 and the second circulation pump 62, and is configured to control the opening and closing of the second stop valve 52 and the second circulation pump 62 according to the cold storage temperature Tc or the liquid level Hc, so as to realize automatic control of cold storage in the cold storage device 2.

Wherein, the heat exchange medium can be water, brine or other refrigerant media which can be used for heat exchange. The heat exchanger 3 may be independent of the refrigerator 4 or may be integrated inside the refrigerator 4, as shown in fig. 1. The refrigeration system of the refrigerator 4 includes an evaporating coil 41, a condensing coil 42, a compressor 43, and an electronic expansion valve. The evaporating coil 41, the compressor 43, the condensing coil 42 and the refrigerant outlet and the refrigerant inlet of the electronic expansion valve 44 are connected end to end in sequence to form a circulating refrigeration loop.

The first medium channel of the heat exchanger 3 is connected in parallel to two ends of the evaporating coil 41, so that after the refrigerant passes through the electronic expansion valve 44, a part of the refrigerant enters the evaporating coil 41, and the other part of the refrigerant enters the first medium channel. The heat exchange medium flowing through the second medium channel and the refrigerant in the first medium channel complete heat exchange and then flow out of the liquid outlet of the second medium channel into the accommodating cavity 112, so that the refrigerating device 1 can refrigerate. Wherein, the heat exchanger 3 can be a plate type heat exchanger or a shell-and-tube type heat exchanger and the like. When the heat exchanger 3 is a shell-and-tube heat exchanger, the first medium channel is a tube-pass flow channel, and the second medium channel is a shell-pass flow channel.

The refrigeration system provided by the embodiment of the invention can determine whether the temperature and the capacity of the heat exchange medium in the cold storage device 2 meet the refrigeration requirement of the refrigeration device 1 or not according to the cold storage temperature Tc detected by the second temperature sensor and the liquid level height Hc detected by the liquid level sensor. If not, the low-temperature heat exchange medium in the heat exchanger 3 flows into the cold storage device 2 by opening the second stop valve 52 and the second circulating pump 62, so as to cool the cold storage device 2, so as to ensure that the cold storage device 2 has enough cold capacity, and meet the requirement of continuous refrigeration of the refrigeration device 1.

Because the cold storage device 2 may have cold loss in actual use, when the temperature of the heat exchange medium in the cold storage cavity 21 is high, the heat exchange medium in the cold storage cavity 21 can automatically flow into the liquid return cavity 22 by opening the third stop valve 53, and the heat exchange medium flows back to the second medium channel through the liquid return cavity 22 to be cooled again. The cold storage efficiency of the cold storage device 2 can be improved while the temperature of the heat exchange medium entering the refrigeration device 1 from the cold storage cavity 21 is ensured to be below the set temperature. Wherein the third shut-off valve 53 is communicatively connectable to the controller.

The cold storage cavity 21 and the liquid return cavity 22 are arranged in the cold storage device 2, so that the high-temperature heat exchange medium used by the refrigeration device 1 flows back to the liquid return cavity 22, and then flows back to the second medium channel from the liquid return cavity 22 to be cooled again. Thereby forming a closed-loop circulating system, so that the heat exchange medium can circularly flow among the refrigerating device 1, the cold storage device 2 and the heat exchanger 3, and saving energy.

According to the embodiment of the invention, the cold storage device 2, the heat exchanger 3 and the refrigerator 4 are arranged, the refrigeration system of the refrigerator 4 is utilized to cool the heat exchange medium flowing through the heat exchanger 3 and then convey the cooled heat exchange medium to the cold storage device 2 for storage, so that the cold storage device 1 can be used during refrigeration, a compressor is not required to be additionally and independently configured for the refrigeration device 1, the cost of the refrigeration device is saved, and continuous refrigeration of the refrigeration device can be realized. When the refrigerating device is an air conditioner fan, ice water or an ice box does not need to be replaced repeatedly. The refrigerating device 1, the cold storage device 2 and the heat exchanger 3 form a closed-loop circulating system by arranging the cold storage cavity 21 and the liquid return cavity 22 in the cold storage device 2, so that energy is saved. The opening and closing of the second stop valve 52, the third stop valve 53 and the second circulating pump 62 can be controlled according to the cold storage temperature Tc and the liquid level height Hc in the cold storage cavity 21 to control the cold storage of the cold storage device 2, so that the cold storage device 2 is ensured to store enough cold to meet the continuous refrigeration requirement of the refrigeration device 1 and improve the cold storage efficiency.

A first stop valve 51 and a first circulating pump 61 are arranged on a communication pipeline between the accommodating cavity 112 and the second medium channel. The accommodating cavity 112 is internally provided with a first temperature sensor for detecting the refrigeration temperature Tz of the heat exchange medium in the accommodating cavity 112, and the first temperature sensor is in communication connection with the controller. The first circulation pump 61 is used for driving the heat exchange medium to flow into the accommodating cavity 112. The controller may be configured to output the cooling temperature Tz so that the user opens or closes the first cutoff valve 51 and the first circulation pump 61 according to the cooling temperature Tz. Or, the controller is in communication connection with the first cut-off valve 51 and the first circulation pump 61, and is configured to control the first cut-off valve 51 and the first circulation pump 61 to be opened or closed according to the detected cooling temperature Tz, so as to realize automatic control of the cooling temperature Tz of the cooling device 1.

Further, the first stop valve 51 and the first circulation pump 61 are both disposed on a communication pipeline between the accommodating chamber 112 and the heat storage device 2. When the cooling capacity in the refrigeration device 1 is insufficient, the first stop valve 51 and the first circulation pump 61 are opened to convey the low-temperature heat exchange medium stored in the cold storage device 2 into the accommodating cavity 112, and at the same time, the higher-temperature heat exchange medium in the accommodating cavity 112 is discharged from the liquid outlet, so that the cooling capacity is supplemented to the refrigeration device 1. Of course, the first stop valve 51 and the first circulation pump 61 may be opened at the same time when the refrigeration apparatus 1 starts cooling.

It should be noted that the liquid inlet of the accommodating cavity 112 is communicated with the cold storage cavity 21 through a first pipeline, the liquid outlet of the accommodating cavity 112 is communicated with the liquid return cavity 22 through a second pipeline, the liquid inlet of the second medium channel is communicated with the liquid return cavity 22 through a third pipeline, and the liquid outlet of the second medium channel is communicated with the cold storage cavity 21 through a fourth pipeline. Both the first cutoff valve 51 and the first circulation pump 61 may be provided on the first pipe or the second pipe. The second stop valve 52 and the second circulation pump 62 may be disposed on the third line and may be disposed on the fourth line.

The number of the first and

second cutoff valves

51 and 52 may be plural. The first pipeline is provided with a first stop valve 51 near both the liquid outlet of the cold storage cavity 21 and the liquid inlet of the accommodating cavity 112, and the second pipeline is provided with a first stop valve 51 near both the liquid outlet of the accommodating cavity 112 and the liquid inlet of the liquid return cavity 22. The third pipeline is close to the liquid outlet of the liquid return cavity 22 and the liquid inlet of the second medium channel and can be provided with a second stop valve 52, and the fourth pipeline is close to the liquid outlet of the second medium channel and can be correspondingly provided with a second stop valve 52.

The refrigeration system provided by the embodiment of the invention can operate in a refrigeration mode or a cold accumulation mode. Specifically, when the refrigeration apparatus 1 is turned on, a refrigeration mode is entered; when the refrigeration apparatus 1 is turned off, the cooling mode is exited. When the first cut-off valve 51 and the first circulation pump 61 are opened, the first cold storage mode is entered; when the first cut-off valve 51 and the second circulation pump 62 are closed, the first cold storage mode is exited. When the second cutoff valve 52 and the second circulation pump 62 are opened, the second cold storage mode is entered; when the second cutoff valve 52 and the second circulation pump 62 are closed, the second cold storage mode is exited.

According to the refrigeration system provided by the invention, the control system can operate the first cold accumulation mode as the refrigeration device 1 for cold accumulation or operate the second cold accumulation mode as the cold storage device 2 for cold accumulation in the valley power time period, so that a user can use the refrigeration system outside the valley power time period. Or different cold accumulation control strategies are adopted within the valley power period and outside the valley power period so as to reduce the influence of the use of the refrigerating device 1 on the power grid and save the electric quantity for users.

Further, as shown in fig. 1, the cold storage device 2 includes a box body 23, a vacuum thermal insulation layer is disposed in the box body 23 to separate the box body 23 into a cold storage cavity 21 and a liquid return cavity 22, so as to prevent the heat exchange between the heat exchange medium in the cold storage cavity 21 and the heat exchange medium in the liquid return cavity 22.

In some embodiments of the present invention, the refrigeration system further comprises a room temperature sensor (not shown in the figure), which is in communication with the controller, for detecting the room temperature Ts at which the refrigeration apparatus 1 is located. The controller determines the consumption rate of the heat exchange medium in the heat storage device 2 when the refrigeration device 1 operates in the refrigeration mode, based on the indoor temperature Ts. So as to determine the target liquid level Hc of the low-temperature heat exchange medium input into the cold storage device 2 when the second cold storage mode is executed, and reduce energy waste.

Further, a fourth stop valve 54 is arranged on the liquid inlet pipeline or the liquid outlet pipeline communicated with the first medium channel. Optionally, a fourth shut-off valve 54 is communicatively connected to the controller. When the second cold storage operation mode is started, the fourth cut-off valve 54 is simultaneously opened. When the second cold accumulation mode is exited, the fourth stop valve 54 is closed at the same time to prevent the refrigerant in the refrigerator 4 from flowing into the first medium channel of the heat exchanger 3, thereby reducing unnecessary cold loss.

The refrigerating apparatus 1 in the embodiment of the present invention may be an apparatus having a refrigerating function, such as an air conditioning fan or a refrigerator. In some embodiments of the present invention, the refrigeration apparatus 1 further includes a cold storage tube 111, a heat exchange tube 12, and a fan (not shown in the figure). The regenerator 111 is located in the accommodating cavity 112. Two ends of the heat exchange tube 12 are respectively communicated with two ends of the cold storage tube 111 to form a closed refrigerant circulation pipeline, and the fan is used for driving air to flow through the heat exchange tube 12.

The regenerator 111 is located in the heat exchange medium in the accommodating cavity 112, and the regenerator 111 and the accommodating cavity 112 form the refrigeration module 11 of the refrigeration device 1. The heat exchange tube 12 and the cold storage tube 111 can be both disc-shaped tubes or heat exchange tube bundles including a plurality of straight tubes, so as to increase the heat exchange area between the refrigerant in the cold storage tube 111 and the heat exchange medium in the accommodating cavity 112. The heat exchange tube 12 and the cold storage tube 111 are made of materials with high heat conductivity coefficient, such as copper or stainless steel.

Alternatively, both ends of the cold storage tube 111 are connected to the side wall of the accommodating chamber 112, and both ends of the heat exchange tube 12 are connected to the side wall of the accommodating chamber 112. The side wall of the accommodating cavity 112 is provided with a heat insulating layer to form a heat insulating box, so that heat exchange between the refrigeration module 11 in the accommodating cavity and the external environment is reduced, and the refrigeration capacity is saved.

Through setting up confined refrigerant circulation pipeline. The refrigerant in the refrigerant circulation pipeline is cooled by the heat exchange medium in the refrigeration module 11. The refrigerant can be recycled in the closed refrigerant circulating pipeline without replacement. The fan drives the air to exchange heat with the heat exchange tube 12, so that the relative humidity of the air in the environment is not increased, the breeding of bacteria can be reduced, and the damage to the health of a human body is reduced.

Optionally, the accommodating cavity 112 is located above the heat exchange tube 12. The refrigerant in the cold storage tube 111 is condensed into a low-temperature liquid refrigerant under the action of the heat exchange medium. The low-temperature liquid refrigerant flows into the heat exchange tube 12 under the action of gravity. The fan drives indoor high-temperature air to pass through the heat exchange tube 12, and after heat exchange is performed between the indoor high-temperature air and the liquid refrigerant in the heat exchange tube 12, the low-temperature liquid refrigerant is converted into a high-temperature gaseous refrigerant, and the high-temperature gaseous refrigerant naturally rises and flows back to the cold storage tube 111. The refrigerant returned to the cold storage tube 111 is re-condensed into a low temperature liquid refrigerant, and thus is circulated.

In the whole circulation process of the refrigerant, the refrigerant can be circulated autonomously without a pumping device, and the refrigerant circulating device is noiseless and saves energy. Of course, the accommodating cavity 112 may be disposed below the heat exchange tube 12, and a circulation pump may circulate the refrigerant between the two. If the cooling capacity of the heat exchange medium in the accommodating cavity 112 is insufficient, the heat exchange medium cooled by the heat exchanger 3 is input into the accommodating cavity 112, so as to ensure the refrigeration effect.

Optionally, a fifth stop valve 13 is disposed on the refrigerant circulation pipeline, and the fifth stop valve 13 is in communication with the controller. When the air conditioner fan is turned off, the fifth cutoff valve 13 is simultaneously closed. Further, a fifth cutoff valve 13 is installed between the outlet of the heat exchange tube 12 and the inlet of the cold storage tube 111. The air conditioner is used for preventing the gasified refrigerant from continuously flowing back to the accommodating cavity 112 after the cold accumulation type air conditioner fan is turned off, so that the loss of cold energy in the accommodating cavity 112 is avoided.

Optionally, a flow regulating valve 14 is disposed on the refrigerant circulation pipeline, and the flow regulating valve 14 is in communication with the controller. The refrigerant flow entering the heat exchange tube 12 can be adjusted by adjusting the opening degree of the flow adjusting valve 14, so that the air outlet temperature of the refrigerating device 1 can be accurately controlled. The flow regulating valve 14 is an electromagnetic flow regulating valve such as an electronic expansion valve.

The air conditioning fan further comprises a water pan 15, and the water pan 15 is located below the heat exchange tube 12. When the surface temperature of the heat exchange pipe 12 is lower than the indoor air temperature, the surface of the heat exchange pipe 12 generates condensed water. The water receiving tray 15 is used for receiving the condensed water flowing down from the heat exchange pipe 12. The drip tray 15 is made of a rust-resistant material, such as a stainless steel tray.

The invention also provides a control method of the refrigeration system. Fig. 2 is a schematic flow chart of a control method of a refrigeration system according to the present invention.

In some embodiments of the present invention, the control method of the refrigeration system comprises:

step S100, obtaining the current time and the refrigerating temperature Tz of the heat exchange medium in the refrigerating device 1 according to a preset time interval;

step S200, determining that the current time is within a preset valley period and the refrigerating temperature Tz is greater than a first set temperature T1, and controlling the first stop valve 51 and the first circulation pump 61 to open.

Wherein, the refrigeration system further comprises a time module for obtaining the current time. After the locating information that can acquire refrigerating plant 1, acquire the power consumption low ebb time period in place area through the thing networking to confirm the power consumption low ebb time period that acquires for predetermineeing the ebb time period, and can realize automatic updating.

The first set temperature T1 is set to the temperature of the internal heat exchange medium of the refrigeration apparatus 1 when cold needs to be supplemented in the valley period, that is, the temperature at which the first cold accumulation mode needs to be started, for example, 25 ℃. The preset valley power period may be set in a power consumption valley period within one day, such as 24 to 5. In the electricity consumption valley period, the power grid load is small, the electric quantity loss is less, the energy utilization rate can be improved, and the energy waste is reduced. And the electricity price in the electricity consumption valley period is lower, so that the electricity consumption cost can be saved for the user.

Specifically, the cooling temperature Tz is detected by the first temperature sensor. When the current time is in the preset valley electricity time period, if the refrigerating temperature Tz is detected to be higher than the first set temperature T1, the refrigerating capacity of the heat exchange medium in the refrigerating device 1 is insufficient, and at the moment, the first stop valve 51 and the first circulating pump 61 are controlled to be opened so as to operate the first cold accumulation mode and convey the low-temperature heat exchange medium into the refrigerating device 1. If the cooling temperature Tz is less than or equal to the first set temperature T1, the first cut-off valve 51 and the first circulation pump 61 are controlled to be closed to exit the first cold storage mode.

In the control method of the refrigeration system provided by the embodiment of the invention, the first stop valve 51 and the first circulating pump 61 are controlled to be opened according to the refrigeration temperature in the refrigeration device 1 in the preset valley power period to store cold for the refrigeration device 1, so that the off-peak power consumption of the refrigeration device 1 is realized, the load of a power grid in the peak power period is reduced, and the power consumption of the refrigeration device 1 is reduced.

step S210, after the current time is determined to be within the preset valley power period in step S200, obtaining the cold storage temperature Tc of the heat exchange medium in the cold storage device 2.

Step S220, determining that the cooling temperature Tz is greater than a first set temperature T1, and the cold storage temperature Tc is less than a second set temperature T2, and controlling the first stop valve 51 and the first circulation pump 61 to be opened.

The first set temperature T1 is a set temperature at which the refrigeration device 1 needs to start cold accumulation, such as 10 ℃ to 20 ℃, and can be selected to be 15 ℃, and the second set temperature T2 is a temperature at which the heat exchange medium in the cold storage device 2 is suitable for cold accumulation of the refrigeration device 1, and can be set according to an actual refrigeration requirement of the refrigeration device 1, such as 5 ℃ to 15 ℃, and can be selected to be 10 ℃.

Specifically, when it is detected that the cooling temperature Tz is higher than the first set temperature T1, it indicates that the cooling device 1 needs to start cold storage. When the cold storage temperature Tc is lower than the second set temperature T2, it indicates that the temperature of the heat exchange medium in the cold storage device 2 can meet the refrigeration demand of the refrigeration device 1, and at this time, the first cold storage mode is started to operate.

According to some embodiments of the invention, the method of controlling a refrigeration system further comprises:

step S310, obtaining a cold storage temperature Tc of the heat exchange medium in the cold storage device 2.

Step S320, determining that the current time is outside the preset valley power period, and acquiring a first control instruction for starting the refrigeration device.

Step S330, determining that the refrigerating temperature Tz is greater than a third set temperature T3, and the cold storage temperature Tc is less than a second set temperature T2, and controlling the first stop valve 51 and the first circulating pump 61 to be opened; wherein the third set temperature T3 > the first set temperature T1.

Wherein the third set temperature T3 is the set temperature at which the refrigeration apparatus 1 needs to start cold storage outside the valley period. It may be set to a temperature at which the cooling capacity in the refrigeration unit 1 is depleted, for example 18 c to 22 c, optionally 20 c.

Specifically, when the current time is outside the preset valley power period, if the refrigeration apparatus 1 is in the off state, the first cold storage mode is not operated. When the refrigeration apparatus 1 operates in the refrigeration mode after receiving the start instruction, the maximum limit value (the third set temperature T3) of the refrigeration temperature Tz outside the preset valley power period is set to be higher than the maximum limit value (the first set temperature T1) of the refrigeration apparatus 1 inside the preset valley power period, so that the number of times of cold accumulation for the refrigeration apparatus 1 in the time outside the preset valley power period is reduced, and energy is saved.

In the above embodiment, after the first stop valve 51 and the first circulation pump 61 are opened, the method further includes: and if any condition of meeting the conditions that the refrigerating temperature Tz is not less than the fourth set temperature T4, the cold storage temperature Tc is not less than the second set temperature T2, the liquid level height Hc of the heat exchange medium in the cold storage device 2 is not more than the first set height H1 and a second control instruction for closing the refrigerating device 1 is obtained is determined, the first stop valve 51 and the first circulating pump 61 are controlled to be closed so as to exit the first cold storage mode.

The fourth set temperature T4 is the temperature of the heat exchange medium inside the refrigeration apparatus 1 when the refrigeration capacity is fully stored, and may be, for example, -10 ℃ to 0 ℃, or-5 ℃. The first set height H1 may be set to 0% to 10%, optionally 5%, of the maximum liquid level height at which the heat exchange medium can be stored in the cold storage device 2.

step S410, determining that the first stop valve 51 and the first circulation pump 61 are turned on within the preset valley power period to operate the first cold storage mode every day for a preset number of consecutive days, and the refrigeration device 1 is turned on outside the preset valley power period to operate the refrigeration mode without operating the first cold storage mode.

Step S420, acquiring a cold accumulation duration when the refrigeration temperature Tz is decreased from the first set temperature T1 to the fourth set temperature value T4 within the preset valley electricity time period during the first cold accumulation mode operating within the preset valley electricity time period every day for the continuous preset days, and calculating an average cold accumulation duration tp for the continuous preset days.

And step S430, controlling the first cut-off valve 51 and the first circulation pump 61 to be opened at the time of the average cooling time tp before the last time of the preset valley power period.

In step S440, the first cut-off valve 51 and the first circulation pump 61 are controlled to be closed at the last time of the preset valley power period.

Specifically, at the time of initial use, the first cold storage mode is started to operate at a default timing within a preset valley power period (such as a start timing of the preset valley power period). After the preset days, the time for starting the first cold accumulation mode in the preset valley power period is determined according to the cold accumulation duration in the preset days and the last moment of the valley power period, so that the cold capacity of the refrigerating device 1 can meet the average refrigerating requirement of the user before the last moment of the valley power period. When the continuous use days are less than the set days, the continuous use days are all defaulted to the first use.

For example, the fourth set temperature T1 is-5 ℃, and the last moment of the preset valley power period is 5 a.m.. In the preset valley electricity time period of the first day, the first set temperature T1 is 18 ℃, the first cold accumulation mode starts to operate when the refrigerating temperature Tz of the refrigerating device 1 reaches 18 ℃, and the cold accumulation time tp consumed when the refrigerating temperature Tz reaches-5 ℃ when the refrigerating temperature Tz reaches cold accumulation capacity is 120min. The cold accumulation time periods of the second day and the third day are respectively 80min and 100min according to the same method, and the average cold accumulation time period tp of the three days is 100min. Then, starting on the fourth day, the first cold storage mode is operated at 3.

step S510, determining that the first stop valve 51 and the first circulation pump 61 are turned on within the preset valley power period to operate the first cold storage mode every day within a preset number of consecutive days, and turning on the refrigeration apparatus 1 to operate the refrigeration mode and not to operate the first cold storage mode outside the preset valley power period.

And step S520, performing numerical correction on the first set temperature T1 after the continuous preset days according to the change condition of the refrigerating temperature Tz outside the preset valley electricity time period every day in the continuous preset days.

Specifically, when the refrigeration apparatus 1 is used for the first time, the first set temperature T1 is the starting temperature for starting the operation of the first cold storage mode within the artificially set valley electric period. After the refrigeration apparatus 1 is continuously used for a preset number of days (for example, 3 days), the first set temperature T1 is numerically corrected according to the actual use condition of the refrigeration apparatus 1 outside the preset off-peak electricity period. When the continuous use days are less than the set days, the continuous use days are all defaulted to the first use.

The embodiment of the invention corrects the value of the first set temperature T1 based on the condition that only the refrigeration mode is operated and the first cold accumulation mode is not operated outside the preset valley power period. The aim is to determine that the refrigeration device 1 can meet the refrigeration demand of the user outside the preset valley electricity time period without cold accumulation. So that when the cold storage device 2 is used for storing cold for the refrigerating device 1 in the preset valley electricity time period, the cold storage can be carried out according to general requirements, and the energy waste is avoided.

Wherein, in step S420, performing a numerical correction on the first set temperature T1 according to the change condition of the cooling temperature Tz outside the preset valley power time period every day in the consecutive preset number of days includes:

step S521, obtaining a first refrigerating temperature Tz1 when the refrigerating apparatus 1 is turned on for the first time and a second refrigerating temperature Tz2 when the refrigerating apparatus 1 is turned off for the last time outside the preset valley power period every day in the continuous preset days.

Step S522 determines the corrected first set temperature T1 according to the first cooling temperature Tz1, the second cooling temperature Tz2, and the fourth set temperature T4.

Specifically, a temperature difference value Δ Tz between a first cooling temperature Tz1 and a second cooling temperature Tz2 for each day for a preset number of consecutive days is calculated, and an average temperature difference value of the temperature difference values Δ Tz for the preset number of days is calculated, and a first set temperature T1 is determined as a difference value between the average temperature difference value and a fifth set temperature T5. The corrected first set temperature T1 is the sum of the fourth set temperature T4 and the temperature difference Δ Tz.

For example, the fourth set temperature T5 is set to-5 ℃. The first refrigeration temperature Tz1 of the refrigeration device 1 at the first opening outside the preset valley power period of the first day is-2 ℃, the second refrigeration temperature Tz2 at the last closing is 20 ℃, and the temperature difference Δ Tz at the first day is 22 ℃. The temperature difference Δ Tz between the second day and the third day was calculated to be 20 ℃ and 18 ℃ respectively according to the same method, and the average temperature difference Δ Tz between the three days was 20 ℃. The first set temperature T1 is calculated to be 15 deg.c. Starting from the fourth day, in the preset valley power period, when the refrigerating temperature Tz of the refrigerating device 1 reaches 15 ℃, the first cold accumulation mode is started to supplement cold energy to the refrigerating device 1.

step S610, obtaining the operating frequency F of the compressor 43 in the refrigerator 4 according to a preset time interval.

Step S620, determining that the working frequency F is less than a set working frequency, and obtaining a cold storage temperature Tc and a liquid level height Hc of the heat exchange medium in the cold storage cavity 21.

Step S630, controlling the opening and closing of the second stop valve 52, the third stop valve 53, and the second circulation pump 62 according to the cold storage temperature Tc and the liquid level height Hc.

Wherein the refrigeration system further comprises a frequency obtaining module for obtaining the operating frequency F of the compressor 43. The cold storage temperature Tc may be detected by the second temperature sensor, and the liquid level height Hc may be detected by the liquid level sensor. The third stop valve 53 is a normally closed valve, and when it is necessary to allow the heat exchange medium in the cold storage chamber 21 to automatically flow into the liquid return chamber 22 by gravity, the third stop valve 53 is controlled to open. The system operates in the second cold storage mode when the second cut-off valve 52 and the second circulation pump 62 are turned on, and the system operates out of the second cold storage mode when the second cut-off valve 52 and the second circulation pump 62 are turned off.

According to some embodiments of the present application, the controlling the opening and closing of the second stop valve 52, the third stop valve 53 and the second circulation pump 62 according to the cold storage temperature Tc and the liquid level height Hc in step S630 includes:

and determining that the cold storage temperature Tc is less than or equal to a second set temperature T2 and the liquid level height Hc is less than or equal to a second set height H2, controlling the third stop valve 53 to be closed, and controlling the second stop valve 52 and the second circulating pump 62 to be opened.

The second set temperature T2 is set to the temperature of the internal heat exchange medium of the cold storage device 2 when cold is required to be supplemented, that is, the cold storage temperature Tc when the second cold storage mode needs to be operated, for example, 10 ℃. The second set height H2 is the liquid level height Hc of the internal heat exchange medium of the cold storage device 2 when cold is required to be replenished, i.e. the liquid level height Hc when the second cold storage mode is required to be operated.

When the cold storage temperature Tc is lower than the second set temperature T2 and the liquid level Hc is lower than the second set height H2, it indicates that the temperature of the heat exchange medium in the cold storage device 2 can meet the refrigeration demand of the refrigeration device 1, but the capacity of the heat exchange medium is not enough to meet the refrigeration demand of the refrigeration device 1, at this time, the third stop valve 53 is closed and the second cold storage mode is started to operate, so as to supplement cold for the cold storage device 2.

Further, the control method of the refrigeration system further comprises the following steps: and acquiring the current time according to a preset time interval. Determining that the current time is within a preset valley power time period, and then taking the second set height H2 as a first set value H21; otherwise, the second set height H2 is set to be the second set value H22. Wherein the first set value H21 > the second set value H22.

And under the condition that the cold storage temperature Tc is lower than the second set temperature T2, determining the value of the second set height H2 according to whether the current time is in the preset valley power time period.

For example, if the current time is within the preset valley power period and the cold storage temperature Tc is lower than 10 ℃, the second set height H2 is 70% of the maximum liquid level height at which the heat exchange medium can be stored in the cold storage device 2. If the current time is out of the preset valley power time period and the cold storage temperature Tc is lower than 10 ℃, the second set height H2 is 10% of the maximum liquid level height at which the heat exchange medium can be stored in the cold storage device 2. That is, within the preset valley power period, the second cold accumulation mode is started when the cold consumption of the device to be cooled 2 is less. And when the off-peak electricity time period is not preset, the second cold accumulation mode is started to operate when the cold energy consumption of the cold storage device 2 is more, so that the cold accumulation times of the cold storage device 2 outside the off-peak electricity time period are reduced, and the energy is saved.

In some embodiments of the present invention, the control method of the refrigeration system further comprises: determining that the working frequency F is less than a set working frequency, and controlling the fourth stop valve 54 to open; otherwise, the fourth cut-off valve 54 is controlled to be closed.

Wherein the set operating frequency may be set to be not higher than the operating frequency of the compressor 43 in the full load state of the refrigerator 4. When the working frequency F of the compressor 43 is less than the set working frequency, indicating that the refrigerator 4 is in a less-than-full-load operation state, the fourth stop valve 54 is opened at this time, and the refrigerant in the refrigerator 4 is allowed to enter the first medium channel, so that the heat exchanger 3 can perform a function of cooling the heat exchange medium. When the working frequency F of the compressor 43 is not less than the set working frequency, indicating that the refrigerator 4 is in a full-load operation state, the fourth stop valve 54 is closed to prevent the refrigerant from entering the first medium passage, so as to preferentially meet the refrigeration requirement of the refrigerator 4.

According to some embodiments of the present invention, the controlling the opening and closing of the second stop valve 52, the third stop valve 53 and the second circulation pump 62 according to the cold storage temperature Tc and the liquid level Hc in step S630 includes:

step S631, determining that the cold storage temperature Tc > a second set temperature T2 and the liquid level Hc > 0, controlling the third cut-off valve 53 to open;

in step S632, if it is determined that the liquid level Hc =0 after the third stop valve 53 is controlled to be opened, the third stop valve 53 is controlled to be closed, and the second stop valve 52 and the second circulation pump 62 are controlled to be opened.

Specifically, when the cold storage temperature Tc is higher than the second set temperature T2, the third stop valve 53 is controlled to open, so that the heat exchange medium in the cold storage chamber 21 automatically flows into the liquid return chamber 22. When all the heat exchange medium in the cold storage cavity 21 flows into the liquid return cavity 22, the third stop valve 53 is closed, and the second cold storage mode is started to operate. Therefore, the cold storage device 2 can rapidly obtain the low cold storage temperature Tc, and the cold storage efficiency is improved.

According to some embodiments of the present invention, after controlling the second stop valve 52 and the second circulation pump 62 to be opened in the above embodiments, the method further includes:

and S640, if the liquid level height Hc is larger than or equal to a third set height H3 and the working frequency F is not smaller than the set working frequency, controlling the second stop valve 52 and the second circulating pump 62 to be closed.

The second set height H2 is a liquid level height Hc corresponding to the time when the cold energy in the cold storage device 2 reaches the set required cold energy. And when the second cold accumulation mode is operated, the liquid level Hc in the cold storage device 2 is detected in real time. And when the liquid level height reaches the third set height H3 or more, the second cold accumulation mode is exited.

According to some embodiments of the invention, the method of controlling a refrigeration system further comprises: and acquiring the current time according to a preset time interval. Determining that the current time is within a preset valley power period, and then taking the third set height H3 as a third set value H31; otherwise, taking the third set height H3 as a fourth set value H32; wherein the third setting H31 > the fourth setting H32.

And under the condition that the cold storage temperature Tc is lower than the second set temperature T2, determining the value of the third set height H3 according to whether the current time is in the preset valley power time period.

For example, if the current time is within the preset valley power period and the cold storage temperature Tc is lower than 10 ℃, the third set height H3 is 95% of the maximum liquid level height at which the heat exchange medium can be stored in the cold storage device 2. If the current time is outside the preset valley electricity time period and the cold storage temperature Tc is lower than 10 ℃, the second set height H2 is 40% of the maximum liquid level height of the heat exchange medium which can be stored in the cold storage device 2. That is, during the preset off-peak electricity period, more cold energy is stored in the cold storage device 2. And when the energy consumption is not within the preset valley power time period, less cold energy is stored in the cold storage device 2, so that the energy consumption generated by the cold storage device 2 outside the valley power time period is reduced, and the energy is saved.

Further, the first setting value H21 is equal to the third setting value H31. That is, if the current time is within the preset valley power period and the cold storage temperature Tc of the heat exchange medium inside the cold storage device 2 is lower than the temperature at which the cold storage device needs to supplement cold, the low-temperature heat exchange medium is input into the cold storage device 2 by operating the second cold storage mode, so that the liquid level Hc in the cold storage device 2 is always kept at the first set value H21.

step S710, determining that the second stop valve 52 and the second circulation pump 62 are turned on within the preset valley power period to operate the second cold accumulation mode every day in the consecutive preset days, and turning on the refrigeration apparatus 1 outside the preset valley power period to operate the refrigeration mode without operating the second cold accumulation mode.

Step S720, performing a numerical correction on the third setting value H31 according to the change condition of the liquid level Hc outside the preset valley power time period every day in the continuous preset days.

Specifically, at the time of initial use of the system, the third set value H31 is the initial liquid level at which the second cold storage mode is started to operate within the artificially set valley period, for example, the highest liquid level at which the cold storage device 2 can store the heat exchange medium. After the system is continuously used for a preset number of days (for example, 3 days), the third set value H31 is numerically corrected according to the actual usage amount of the heat exchange medium in the heat storage device 2 outside the preset valley power period. When the continuous use days are less than the set days, the continuous use days are all defaulted to the first use.

The embodiment of the present invention performs the numerical correction of the third set value H31 based on the case where only the cooling mode is operated without operating the second cold storage mode outside the preset valley power period. The aim is to determine that the cold storage device 2 can meet the refrigeration requirement of a user outside a preset valley electricity time period under the condition of not carrying out cold storage. So that the cold accumulation of the refrigerating device 1 in the preset valley electricity time period can be carried out as required by utilizing the heat exchanger 3, and the energy waste is avoided.

In step S720, numerically correcting the third setting value H31 according to the change of the liquid level Hc outside the preset valley power time period every day in the consecutive preset days includes:

step S721 is to obtain an average air temperature Tp in a day after the preset valley power period where the current time is, and calculate a temperature difference Δ T between the average air temperature Tp and a set indoor temperature Tss.

Step S722, acquiring an indoor temperature Ts in real time in a set time period outside the preset valley power period every day in the consecutive preset days, and determining a first reduction value Δ Hc1 of the liquid level Hc when the indoor temperature Ts decreases by a set temperature value (for example, 1 ℃) and a second reduction value Δ Hc2 of the liquid level Hc when the indoor temperature Ts is stabilized within a set range in unit time.

Step S723, obtaining a total time length T of the refrigeration mode running each day in the preset consecutive days, and determining the corrected third setting value H31 according to the temperature difference Δ T, the first reduction value Δ Hc1, the second reduction value Δ Hc2, and the total time length T.

Wherein the time other than the preset valley power period comprises the daytime. The set time period described in step S722 may be set to a time period in which the indoor temperature Ts is generally at the highest outside the preset valley power period, such as 11. When the indoor temperature Ts falls to the set indoor temperature Tss, the indoor temperature Ts is stabilized within the set range by adjusting the opening degree of the flow rate adjustment valve in the refrigeration apparatus 1. The set range may be a range of the set indoor temperature Tss ± 1 ℃. When the system operates in the cooling mode, the indoor temperature Ts set by the user is set, that is, the target temperature of the cooling device 1.

Specifically, after the first reduction value Δ Hc1, the second reduction value Δ Hc2 and the total time length t are obtained, an average value Hp1 of the first reduction value Δ Hc1, an average value Hp2 of the second reduction value Δ Hc2 and an average value tp of the total time length t for a preset number of consecutive days are calculated. The corrected third set value H31= the first set height H1+ Hp1 × Δ T + Hp2 × tp.

For example, the first set height H1 is 0m, and the room temperature is set to 26 ℃. The average air temperature Tp in one day after the preset valley power period at which the current time is located is calculated to be 35 ℃. And in the set time period, every time the indoor temperature Ts is reduced by 1 ℃ for three consecutive days, the average reduction of the liquid level Hc is 0.1m. During the time when the room temperature Ts was lowered to 26 ℃ and stabilized at 26. + -. 1 ℃, the liquid level Hc was reduced by 0.04m per hour. The average of the total time length of the cooling mode was 8 hours for three consecutive days. Then the corrected third setting value H31 is 0.1 × 9+0.03 × 8=1.22m.

Finally, it should be noted that: the above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.

Claims

1. A refrigeration system, comprising: the refrigerator comprises a refrigerating device, a cold storage device, a heat exchanger, a refrigerator and a controller;

a second stop valve and a second circulating pump are arranged on a communication pipeline between the cold storage device and the second medium channel; a second temperature sensor and a liquid level sensor are arranged in the cold storage cavity and are respectively used for detecting the cold storage temperature and the liquid level height of the heat exchange medium in the cold storage cavity, and the second temperature sensor and the liquid level sensor are respectively in communication connection with the controller; the cold storage cavity is positioned above the liquid return cavity, the bottom of the cold storage cavity is provided with a water outlet, the liquid return cavity is provided with a water inlet, and a communication pipeline between the water outlet and the water inlet is provided with a third stop valve;

the refrigerant in the first medium channel and the heat exchange medium in the second medium channel can exchange heat.

2. The refrigeration system of claim 1 wherein said cold storage device comprises a tank having a vacuum insulation layer disposed therein to separate said tank into said cold storage chamber and said liquid return chamber.

3. A refrigerating system as recited in claim 1 wherein a fourth shutoff valve is provided in a liquid inlet line or a liquid outlet line communicating with said first medium passage.

4. A control method of a refrigeration system according to any one of claims 1 to 3, comprising:

controlling the second stop valve, the third stop valve and the second circulating pump to be opened and closed according to the cold storage temperature and the liquid level height;

the controlling the opening and closing of the second stop valve, the third stop valve and the second circulating pump according to the cold storage temperature and the liquid level height comprises:

5. The method of claim 4, further comprising:

acquiring current time according to a preset time interval;

determining that the current time is within a preset valley electricity time period, and then taking the second set height as a first set value; otherwise, the second set height is taken as a second set value; wherein the first set value is larger than the second set value.

6. The control method of the refrigeration system according to claim 4, wherein the controlling of the opening and closing of the second stop valve, the third stop valve, and the second circulation pump according to the cold storage temperature and the liquid level further comprises:

7. The control method of the refrigeration system according to any one of claims 4 to 6, further comprising, after the controlling the second shutoff valve and the second circulation pump to be opened:

8. The control method of the refrigeration system as recited in claim 7, further comprising:

acquiring current time according to a preset time interval;

determining that the current time is within a preset valley power time period, and then taking the third set height as a third set value; otherwise, the third set height is taken as a fourth set value; wherein the third set value > the fourth set value.

9. The control method of a refrigerating system as recited in claim 4 wherein if it is determined that the operating frequency is less than a set operating frequency, controlling the opening of the fourth cut-off valve; otherwise, controlling the fourth stop valve to close.