CN117366897A - Refrigerating device and control method thereof - Google Patents

Abstract

The invention provides a refrigerating device and a control method thereof, wherein the refrigerating device comprises a box body, a controller, a high-temperature-level refrigerating circulation loop and a low-temperature-level refrigerating circulation loop; the controller is used for judging the temperature T detected by the second temperature sensor when the temperature signal of the first temperature sensor cannot be acquired ₂ Whether the preset starting temperature T of the second storage compartment is higher than the preset starting temperature T of the second storage compartment _{2 open} The method comprises the steps of carrying out a first treatment on the surface of the If so, the first and second data are not identical,the switching valve is controlled to be switched to be communicated with the second cold supply branch only, and the high-temperature-stage compressor is controlled to be started; after a preset time t1, controlling the low-temperature-stage compressor to start; t (T) ₂ Lowering the temperature to the preset shutdown temperature T of the second storage compartment _{2-pass valve} When the low-temperature-stage compressor is controlled to stop, the switching valve is controlled to be switched to be communicated with the first cold supply branch; after a preset time T2, judging T ₂ Whether the preset starting temperature T of the second storage compartment is higher than the preset starting temperature T of the second storage compartment _{2 open} The method comprises the steps of carrying out a first treatment on the surface of the If not, the high-temperature-stage compressor is controlled to stop. The invention can ensure the normal operation of the refrigerating device under the conditions of fault, damage and the like of the temperature sensor.

Description

Refrigerating device and control method thereof

Technical Field

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

Background

With the development of the technology level, household appliances are becoming more and more popular in the life of residents, and develop towards the intelligent direction, and the temperature of a storage compartment is monitored in a refrigerating device to achieve the effect of temperature control, so that the fresh-keeping storage of food materials, foods and the like stored in the refrigerating device is facilitated. However, temperature monitoring is often performed by relying on a temperature sensor, and in the actual use process, the temperature sensor is often prone to faults, damages and the like, so that the refrigerating device cannot normally operate, and the fresh-keeping storage of food materials, foods and the like is not facilitated.

Disclosure of Invention

In order to solve the technical problems, the invention aims to provide a refrigerating device and a control method thereof, so as to solve the problem that the existing refrigerating device cannot normally operate under the conditions of fault, damage and the like of a temperature sensor.

In order to achieve one of the above objects, an embodiment of the present invention provides a refrigeration apparatus, comprising,

the high-temperature-stage refrigeration cycle loop comprises a high-temperature-stage compressor, a switching valve, a parallel branch and an evaporation part, wherein a first refrigerant circulates in the high-temperature-stage refrigeration cycle loop, the parallel branch comprises a first cooling branch and a second cooling branch which are arranged in parallel, the first cooling branch comprises a first throttling device and a high-temperature-stage evaporator which are arranged in series, the second cooling branch comprises a second throttling device, and the switching valve is selectively communicated with at least one of the first cooling branch and the second cooling branch;

The low-temperature-stage refrigeration cycle loop comprises a low-temperature-stage compressor and a condensation part, wherein a second refrigerant flows in the low-temperature-stage refrigeration cycle loop, and the second refrigerant flowing through the condensation part exchanges heat with the first refrigerant flowing through the evaporation part;

the refrigerator comprises a refrigerator body, a first storage compartment and a second storage compartment, wherein the refrigerator body is provided with a high-temperature-level refrigeration cycle loop for cooling the first storage compartment, a low-temperature-level refrigeration cycle loop for cooling the second storage compartment, a first temperature sensor is arranged in the first storage compartment, and a second temperature sensor is arranged in the second storage compartment;

a controller for controlling the operation of the device,

when the temperature signal of the first temperature sensor cannot be obtained, judging the temperature T detected by the second temperature sensor ₂ Whether the preset starting temperature T of the second storage compartment is higher than the preset starting temperature T of the second storage compartment _{2 open} ；

If yes, the switching valve is controlled to be switched to be communicated with the second cold supply branch only, and the high-temperature-stage compressor is controlled to be started;

after a preset time t1, controlling the low-temperature-stage compressor to start;

the temperature T detected by the second temperature sensor ₂ To the point ofPreset shutdown temperature T of the second storage compartment _{2-pass valve} When the low-temperature-stage compressor is controlled to stop, the switching valve is controlled to be switched to be communicated with the first cold supply branch only;

after a preset time T2, judging T ₂ Whether the preset starting temperature T of the second storage compartment is higher than the preset starting temperature T of the second storage compartment _{2 open} ；

If not, controlling the high-temperature-stage compressor to stop.

As a further improvement of an embodiment of the invention, the controller is also adapted to,

after a preset time T2, if T ₂ >T _{2 open} And controlling the switching valve to be switched to be communicated with the second cold supply branch only, and controlling the low-temperature-stage compressor to start.

As a further improvement of an embodiment of the invention, the controller is also adapted to,

when the temperature signal of the second temperature sensor cannot be obtained, judging the temperature T detected by the first temperature sensor ₁ Whether the preset starting temperature T of the first storage compartment is higher than the preset starting temperature T of the first storage compartment _{1 open} ；

If yes, the switching valve is controlled to be switched to be communicated with the first cold supply branch only, and the high-temperature-stage compressor is controlled to be started;

when a preset condition is met, the switching valve is controlled to be switched to be communicated with the second cold supply branch only, and the low-temperature-stage compressor is controlled to be started;

after a preset time t3, controlling the low-temperature-stage compressor to stop;

Wherein, the preset conditions are as follows: the temperature T detected by the first temperature sensor ₁ The temperature is reduced to a preset shutdown temperature T of the first storage compartment _{1 switch} Alternatively, after a preset time t 4.

As a further improvement of an embodiment of the invention, the controller is also adapted to,

after a preset time T3, if T ₁ The preset shutdown temperature T of the first storage compartment is less than or equal to the preset shutdown temperature T of the first storage compartment _{1 switch} And controlling the high-temperature-stage compressor to stop.

As a further improvement of an embodiment of the invention, the controller is also adapted to,

when the temperature signals of the first temperature sensor and the second temperature sensor cannot be obtained, the switching valve is controlled to be switched to be communicated with the first cold supply branch only, and the high-temperature-stage compressor is controlled to be started;

after a preset time t2, controlling the switching valve to be switched to be communicated with the second cold supply branch only, and controlling the low-temperature-stage compressor to start;

and after a preset time t3, controlling the low-temperature-stage compression stage to stop, and controlling the high-temperature-stage compressor to stop.

As a further improvement of one embodiment of the present invention, the preset temperature T of the first storage compartment _1y When the temperature is between 6 and 10 ℃, controlling t2=3 min;

T _1y When the temperature is between 1 and 5 ℃, controlling t2=4 min;

T _1y when the temperature is between 4 ℃ below zero and 0 ℃, controlling t2=5 min;

T _1y when the temperature is between minus 9 and minus 5 ℃, controlling t2=6 min;

T _1y when the temperature is between minus 13 ℃ and minus 10 ℃, controlling t2=7 min;

T _1y when the temperature is between minus 17 ℃ and minus 14 ℃, controlling t2=8 min;

T _1y when the temperature is between minus 21 and minus 18 ℃, controlling t2=9 min;

T _1y when the temperature is between minus 24 and minus 22 ℃, controlling t2=10 min;

T _1y when the temperature is between minus 27 and minus 25 ℃, controlling t2=11 min;

T _1y at the temperature of between-30 and-28 ℃, controlling t2=12 min.

As a further improvement of one embodiment of the present invention, the preset temperature T of the second storage compartment _2y At the temperature of between-24 and-20 ℃, controlling t3=4 min;

T _2y at the temperature of between 29 and 25 ℃ below zero, controlling t3=5 min;

T _2y when the temperature is between minus 34 ℃ and minus 30 ℃, controlling t3=6 min;

T _2y at the temperature of between-39 and-35 ℃, controlling t3=7 min;

T _2y when the temperature is between-43 and-40 ℃, controlling t3=8 min;

T _2y at the temperature of between-47 and-44 ℃, controlling t3=9 min;

T _2y when the temperature is between minus 51 ℃ and minus 48 ℃, controlling t3=10 min;

T _2y when the temperature is between minus 54 ℃ and minus 52 ℃, controlling t3=11 min;

T _2y when the temperature is between-57 and-55 ℃, controlling t3=12 min;

T _2y at the temperature of between-60 and-58 ℃, controlling t3=13 min.

In order to achieve one of the above objects, an embodiment of the present invention also provides a control method of a refrigeration apparatus, the control method including,

when the temperature signal of the first temperature sensor cannot be obtained, the switching valve is controlled to be switched to be communicated with the second cold supply branch only, and the high-temperature-stage compressor is controlled to be started;

After a preset time t1, controlling the low-temperature-stage compressor to start;

the temperature T detected by the second temperature sensor ₂ The temperature is reduced to a preset shutdown temperature T of the second storage compartment _{2-pass valve} When the low-temperature-stage compressor is controlled to stop, the switching valve is controlled to be switched to be communicated with the first cold supply branch only;

after a preset time T2, judging T ₂ Whether the preset starting temperature T of the second storage compartment is higher than the preset starting temperature T of the second storage compartment _{2 open} ；

If not, controlling the high-temperature-stage compressor to stop.

As a further improvement of one embodiment of the present invention, the control method further includes, after a preset time T2, if T ₂ >T _{2 open} And controlling the switching valve to be switched to be communicated with the second cold supply branch only, and controlling the low-temperature-stage compressor to start.

As a further improvement of an embodiment of the present invention, the control method further includes, when the temperature signal of the second temperature sensor cannot be obtained, controlling the switching valve to be switched to be in communication with only the first cold supply branch, and controlling the high temperature stage compressor to be started;

when a preset condition is met, the switching valve is controlled to be switched to be communicated with the second cold supply branch only, and the low-temperature-stage compressor is controlled to be started;

After a preset time t3, controlling the low-temperature-stage compressor to stop;

wherein, the preset conditions are as follows: the temperature T detected by the first temperature sensor ₁ The temperature is reduced to a preset shutdown temperature T of the first storage compartment _{1 switch} Alternatively, after a preset time t 4.

As a further improvement of one embodiment of the present invention, the control method further includes, after a preset time T3, if T ₁ The preset shutdown temperature T of the first storage compartment is less than or equal to the preset shutdown temperature T of the first storage compartment _{1 switch} And controlling the high-temperature-stage compressor to stop.

As a further improvement of an embodiment of the present invention, the control method further includes, when the temperature signal of the first temperature sensor and the temperature signal of the second temperature sensor cannot be obtained, controlling the switching valve to be switched to be in communication with only the first cooling branch, and controlling the high-temperature-stage compressor to be started;

after a preset time t2, controlling the switching valve to be switched to be communicated with the second cold supply branch only, and controlling the low-temperature-stage compressor to start;

and after a preset time t3, controlling the low-temperature-stage compression stage to stop, and controlling the high-temperature-stage compressor to stop.

Compared with the prior art, the invention has the following beneficial effects: the refrigerating device and the control method of the refrigerating device can ensure the normal operation of the refrigerating device under the conditions of fault, damage and the like of the temperature sensor, thereby avoiding the deterioration and decay of food materials, foods and the like stored in the refrigerating device.

Drawings

Fig. 1 is a schematic structural diagram of an cascade compression refrigeration system according to embodiment 1 of the present invention;

fig. 2 is a schematic structural diagram of an cascade compression refrigeration system according to embodiment 2 of the present invention.

Detailed Description

The present invention will be described in detail below with reference to specific embodiments shown in the drawings.

In the various illustrations of the invention, certain dimensions of structures or portions may be exaggerated relative to other structures or portions for convenience of illustration, and thus serve only to illustrate the basic structure of the inventive subject matter.

It will be understood that, although the terms first, second, etc. may be used herein to describe various elements or structures, these described elements should not be limited by these terms. These terms are only used to distinguish one such descriptive object from another.

The refrigerating device provided by the embodiment of the invention comprises a box body and a door body, wherein the box body is internally provided with a storage compartment, the door body is used for opening or closing the storage compartment, and the refrigerating device further comprises a refrigerating system which is arranged in the box body and supplies cold to the storage compartment. Specifically, the refrigerating device can be set as a refrigerator, a freezer and the like so as to meet the requirements of different users and different application scenes.

Example 1

In this embodiment, the case has a first storage compartment and a second storage compartment, where the first storage compartment may be a refrigeration compartment or a freezing compartment, and the second storage compartment may be a temperature-changing compartment or a cryogenic compartment. The refrigeration system employs an cascade compression refrigeration system 100 that includes a high temperature stage refrigeration cycle 1 and a low temperature stage refrigeration cycle 2.

For convenience of description, in this embodiment, the high-temperature-stage refrigeration cycle 1 is used to cool the first storage compartment, and the low-temperature-stage refrigeration cycle 2 is used to cool the second storage compartment. Of course, the two may be interchanged.

Of course, in other embodiments, other storage compartments besides the first storage compartment and the second storage compartment may be provided according to actual needs.

Referring to fig. 1, the high-temperature-stage refrigeration cycle 1 includes a high-temperature-stage compressor 11, a switching valve 17, a parallel branch, and an evaporation unit 12, which are disposed in series, and a first refrigerant flows through the high-temperature-stage refrigeration cycle 1. The switching valve 17 is disposed at an inlet of the parallel branch, the parallel branch includes a first cooling branch and a second cooling branch, the first cooling branch includes a first throttling device 161 and a high-temperature-stage evaporator 15 that are disposed in series, the second cooling branch includes a second throttling device 162, and the switching valve 17 is selectively communicated with at least one of the first cooling branch and the second cooling branch.

The low-temperature-stage refrigeration cycle 2 includes a low-temperature-stage compressor 22 and a condensation unit 21, and a second refrigerant flows through the low-temperature-stage refrigeration cycle 2, and the second refrigerant flowing through the condensation unit 21 exchanges heat with the first refrigerant flowing through the evaporation unit 12.

Thus, when the first refrigerant circulates in the high-temperature-stage refrigeration cycle 1, the high-temperature-stage evaporator 15 cools the first storage compartment; by exchanging heat between the second refrigerant flowing through the condensation portion 21 and the first refrigerant flowing through the evaporation portion 12, the first refrigerant in the evaporation portion 12 can absorb heat of the second refrigerant flowing through the condensation portion 21, so that the temperature of the second refrigerant in the condensation portion 21 can be further reduced, the low-temperature-stage refrigeration cycle 2 can be pre-cooled, and the low-temperature-stage refrigeration cycle 2 can achieve a lower temperature.

The first refrigerant and the second refrigerant may be the same refrigerant or different refrigerants.

In addition, the "high temperature" and "low temperature" in the "high temperature-stage refrigeration cycle 1" and the "low temperature-stage refrigeration cycle 2" are relatively speaking, and the evaporation temperature of the first refrigerant flowing through the high temperature-stage refrigeration cycle 1 is relatively higher than the evaporation temperature of the second refrigerant flowing through the low temperature-stage refrigeration cycle 2.

The first storage compartment is provided with a first temperature sensor, and the second storage compartment is provided with a second temperature sensor. The first temperature sensor is used for detecting the temperature T in the first storage room ₁ The second temperature sensor is used for detecting the temperature T in the second storage room ₂ 。

The refrigerating apparatus further includes a controller to which the first temperature sensor, the second temperature sensor, the switching valve 17, the high temperature stage compressor 11, and the low temperature stage compressor 12 are connected.

The controller is configured to control the operation of the device,

when the temperature signal of the first temperature sensor cannot be obtained, judging the temperature T detected by the second temperature sensor ₂ Whether the preset starting temperature T of the second storage compartment is higher than the preset starting temperature T of the second storage compartment _{2 open} ；

If yes, the switching valve 17 is controlled to be switched to be communicated with the second cold supply branch only, and the high-temperature-stage compressor 11 is controlled to be started;

after a preset time t1, the low-temperature-stage compressor 22 is controlled to start;

the temperature T detected by the second temperature sensor ₂ The temperature is reduced to a preset shutdown temperature T of the second storage compartment _{2-pass valve} When the low-temperature-stage compressor 22 is controlled to stop, and the switching valve 17 is controlled to be switched to be communicated with the first cold supply branch only;

After a preset time T2, judging T ₂ Whether the preset starting temperature T of the second storage compartment is higher than the preset starting temperature T of the second storage compartment _{2 open} ；

If not, the high-temperature-stage compressor 11 is controlled to stop.

When the temperature signal of the first temperature sensor cannot be obtained, the first temperature sensor is indicated to be faulty, at the moment, the temperature in the first storage compartment cannot be monitored in real time, and the running condition of the refrigerating system can be controlled according to the temperature condition in the second storage compartment. Specifically, if the second storage compartment needs to be refrigerated, the switching valve 17 is controlled to be switched to be communicated with only the second cooling branch, the high-temperature-stage compressor 11 is controlled to be started to pre-cool the condensing portion 21, and after a preset time t1, the low-temperature-stage compressor 22 is controlled to be started to enable the low-temperature-stage refrigeration cycle 2 to cool the second storage compartment; when the temperature in the second storage compartment is reduced to the preset shutdown temperature, the low-temperature-stage compressor 22 is controlled to be shut down so as to save energy consumption, and the switching valve 17 is switched to be communicated with only the first cooling branch, and the high-temperature-stage compressor 11 is still running at this time, so that the first storage compartment can be cooled, and the energy consumption can be saved by controlling the cooling time t2 of the first storage compartment. Therefore, the normal operation of the refrigerating device can be ensured under the conditions of fault, damage and the like of the temperature sensor, so that the deterioration and decay of food materials, foods and the like stored in the refrigerating device are avoided.

Preferably, t1 is less than or equal to 5 minutes, so that sufficient heat dissipation can be obtained in the condensing portion 21.

Further, the controller is also used for controlling the operation of the device,

after a preset time T2, if T ₂ >T _{2 open} The switching valve 17 is controlled to be switched to communicate with only the second cold feed branch and the low temperature stage compressor 22 is controlled to be started.

That is, after controlling the cooling time t2 of the first storage compartment, if the second storage compartment needs to be cooled, the switching valve 17 is controlled to be switched to be only in communication with the second cooling branch, and the low-temperature-stage compressor 22 is controlled to be started, so that the low-temperature-stage refrigeration cycle 2 supplies cooling to the second storage compartment.

Preferably, the duration of T2 is equal to the preset temperature T of the first storage compartment _1y Negative correlation, i.e. T _1y The lower t2 is, the larger t2 is.

Specifically T _1y When the temperature is between 6 and 10 ℃, controlling t2=3 min;

T _1y when the temperature is between 1 and 5 ℃, controlling t2=4 min;

T _1y when the temperature is between 4 ℃ below zero and 0 ℃, controlling t2=5 min;

T _1y when the temperature is between minus 9 and minus 5 ℃, controlling t2=6 min;

T _1y when the temperature is between minus 13 ℃ and minus 10 ℃, controlling t2=7 min;

T _1y when the temperature is between minus 17 ℃ and minus 14 ℃, controlling t2=8 min;

T _1y when the temperature is between minus 21 and minus 18 ℃, controlling t2=9 min;

T _1y when the temperature is between minus 24 and minus 22 ℃, controlling t2=10 min;

T _1y at the temperature of between-27 and-25 ℃, t2=is controlled11min；

T _1y At the temperature of between-30 and-28 ℃, controlling t2=12 min.

Therefore, under the condition that the first temperature sensor fails, the first storage compartment is ensured to be sufficiently cooled, and the energy efficiency of the refrigerating system can be controlled, so that the energy consumption is saved.

Further, the controller is also used for controlling the operation of the device,

when the temperature signal of the second temperature sensor cannot be obtained, judging the temperature T detected by the first temperature sensor ₁ Whether the preset starting temperature T of the first storage compartment is higher than the preset starting temperature T of the first storage compartment _{1 open} ；

If yes, the switching valve 17 is controlled to be switched to be communicated with the first cold supply branch only, and the high-temperature-stage compressor 11 is controlled to be started;

when the preset condition is met, the switching valve 17 is controlled to be switched to be communicated with the second cold supply branch only, and the low-temperature-stage compressor 22 is controlled to be started;

after a preset time t3, the low-temperature-stage compressor 22 is controlled to stop;

wherein, the preset conditions are as follows: the temperature T detected by the first temperature sensor ₁ The temperature is reduced to a preset shutdown temperature T of the first storage compartment _{1 switch} Alternatively, after a preset time t 4.

When the temperature signal of the second temperature sensor cannot be obtained, the second temperature sensor is indicated to be faulty, at the moment, the temperature in the second storage compartment cannot be monitored in real time, and the running condition of the refrigerating system can be controlled according to the temperature condition in the first storage compartment. Specifically, if the first storage compartment needs to be refrigerated, the switching valve 17 is controlled to be communicated with the first cooling branch and the high-temperature-stage compressor 11 is controlled to be started to cool the first storage compartment, until the temperature of the first storage compartment is reduced to the preset shutdown temperature, or after the preset time t4, the switching valve 17 is controlled to be communicated with the first cooling branch and the low-temperature-stage compressor 22 is controlled to be started, so that the low-temperature-stage refrigeration cycle loop 2 is enabled to cool the second storage compartment, and the situation that the second storage compartment cannot be cooled for a long time is avoided; by controlling the cooling time t2 of the second storage compartment, energy consumption can be saved. Therefore, the normal operation of the refrigerating device can be ensured under the conditions of faults, damages and the like of the second temperature sensor, so that the deterioration and decay of food materials, foods and the like stored in the refrigerating device are avoided.

Preferably, the duration of T3 is equal to the preset temperature T of the second storage compartment _2y Negative correlation, i.e. T _2y The smaller t3 is, the larger t3 is.

Specifically T _2y At the temperature of between-24 and-20 ℃, controlling t3=4 min;

T _2y at the temperature of between 29 and 25 ℃ below zero, controlling t3=5 min;

T _2y when the temperature is between minus 34 ℃ and minus 30 ℃, controlling t3=6 min;

T _2y at the temperature of between-39 and-35 ℃, controlling t3=7 min;

T _2y when the temperature is between-43 and-40 ℃, controlling t3=8 min;

T _2y at the temperature of between-47 and-44 ℃, controlling t3=9 min;

T _2y when the temperature is between minus 51 ℃ and minus 48 ℃, controlling t3=10 min;

T _2y when the temperature is between minus 54 ℃ and minus 52 ℃, controlling t3=11 min;

T _2y when the temperature is between-57 and-55 ℃, controlling t3=12 min;

T _2y at the temperature of between-60 and-58 ℃, controlling t3=13 min.

Therefore, under the condition that the second temperature sensor fails, the second storage compartment is ensured to be sufficiently cooled, and the energy efficiency of the refrigerating system can be controlled, so that the energy consumption is saved.

Preferably, t4=30 min, so as to avoid that the second storage compartment is not cooled for a long time.

Further, the controller is also used for controlling the operation of the device,

after a preset time T3, if T ₁ The preset shutdown temperature T of the first storage compartment is less than or equal to the preset shutdown temperature T of the first storage compartment _{1 switch} The high temperature stage compressor 11 is controlled to stop.

That is, after controlling the cooling t3 of the second storage compartment, if the first storage compartment does not need to be cooled, the high-temperature-stage compressor 11 is controlled to stop, so as to reduce the energy consumption of the refrigeration device.

Further, the controller is also used for controlling the operation of the device,

when the temperature signals of the first temperature sensor and the second temperature sensor cannot be obtained, the switching valve 17 is controlled to be switched to be communicated with the first cold supply branch only, and the high-temperature-stage compressor 11 is controlled to be started;

after a preset time t2, the switching valve 17 is controlled to be switched to be communicated with the second cold supply branch only, and the low-temperature-stage compressor 22 is controlled to be started;

after a preset time t3, the low temperature stage compression stage 22 is controlled to stop, and the high temperature stage compressor 11 is controlled to stop.

That is, when the temperature signals of the first temperature sensor and the second temperature sensor cannot be obtained, it indicates that the first temperature sensor and the second temperature sensor are both faulty, and at this time, the temperatures in the first storage compartment and the second storage compartment cannot be monitored in real time, then the switching valve 17 is controlled to be switched to be only in communication with the first cooling branch, and the high-temperature compressor 11 is controlled to be started, so that the high-temperature refrigeration cycle 1 cools the first storage compartment, and the evaporation portion 12 precools the condensation portion 21, and controls the time t2 of the high-temperature refrigeration cycle 1 cooling the first storage compartment according to the preset temperature of the first storage compartment, so that on one hand, the excessively long cooling time of the first storage compartment can be avoided, and the waste of productivity is caused, and on the other hand, the second storage compartment can be avoided from being unable to obtain the cooling time of the second storage compartment for a long time; and then, the switching valve 17 is controlled to be switched to be communicated with the second cooling branch, and the low-temperature-stage compressor 22 is controlled to be started, so that the low-temperature-stage refrigeration cycle loop 2 supplies cold to the second storage compartment, and the time t3 for the low-temperature-stage refrigeration cycle loop 2 to supply cold to the second storage compartment is controlled according to the preset temperature of the second storage compartment, thereby avoiding the excessively long cold supply time of the second storage compartment and wasting productivity.

An embodiment of the present invention also provides a control method of the refrigerating apparatus as described above, which includes,

when the temperature signal of the first temperature sensor cannot be obtained, judging the temperature T detected by the second temperature sensor ₂ Whether the preset starting temperature T of the second storage compartment is higher than the preset starting temperature T of the second storage compartment _{2 open} ；

If yes, the switching valve 17 is controlled to be switched to be communicated with the second cold supply branch only, and the high-temperature-stage compressor 11 is controlled to be started;

after a preset time t1, the low-temperature-stage compressor 22 is controlled to start;

the temperature T detected by the second temperature sensor ₂ The temperature is reduced to a preset shutdown temperature T of the second storage compartment _{2-pass valve} When the low-temperature-stage compressor 22 is controlled to stop, and the switching valve 17 is controlled to be switched to be communicated with the first cold supply branch only;

after a preset time T2, judging T ₂ Whether the preset starting temperature T of the second storage compartment is higher than the preset starting temperature T of the second storage compartment _{2 open} ；

If not, the high-temperature-stage compressor 11 is controlled to stop.

When the temperature signal of the first temperature sensor cannot be obtained, the first temperature sensor is indicated to be faulty, at the moment, the temperature in the first storage compartment cannot be monitored in real time, and the running condition of the refrigerating system can be controlled according to the temperature condition in the second storage compartment. Specifically, if the second storage compartment needs to be refrigerated, the switching valve 17 is controlled to be switched to be communicated with only the second cooling branch, the high-temperature-stage compressor 11 is controlled to be started to pre-cool the condensing portion 21, and after a preset time t1, the low-temperature-stage compressor 22 is controlled to be started to enable the low-temperature-stage refrigeration cycle 2 to cool the second storage compartment; when the temperature in the second storage compartment is reduced to the preset shutdown temperature, the low-temperature-stage compressor 22 is controlled to be shut down so as to save energy consumption, and the switching valve 17 is switched to be communicated with only the first cooling branch, and the high-temperature-stage compressor 11 is still running at this time, so that the first storage compartment can be cooled, and the energy consumption can be saved by controlling the cooling time t2 of the first storage compartment. Therefore, the normal operation of the refrigerating device can be ensured under the conditions of fault, damage and the like of the temperature sensor, so that the deterioration and decay of food materials, foods and the like stored in the refrigerating device are avoided.

Preferably, t1 is less than or equal to 5 minutes, so that sufficient heat dissipation can be obtained in the condensing portion 21.

Further, the control method further comprises,

after a preset time T2, if T ₂ >T _{2 open} The switching valve 17 is controlled to be switched to communicate with only the second cold feed branch and the low temperature stage compressor 22 is controlled to be started.

That is, after controlling the cooling time t2 of the first storage compartment, if the second storage compartment needs to be cooled, the switching valve 17 is controlled to be switched to be only in communication with the second cooling branch, and the low-temperature-stage compressor 22 is controlled to be started, so that the low-temperature-stage refrigeration cycle 2 supplies cooling to the second storage compartment.

Preferably, the duration of T2 is equal to the preset temperature T of the first storage compartment _1y Negative correlation, i.e. T _1y The lower t2 is, the larger t2 is.

Specifically T _1y When the temperature is between 6 and 10 ℃, controlling t2=3 min;

T _1y when the temperature is between 1 and 5 ℃, controlling t2=4 min;

T _1y when the temperature is between 4 ℃ below zero and 0 ℃, controlling t2=5 min;

T _1y when the temperature is between minus 9 and minus 5 ℃, controlling t2=6 min;

T _1y when the temperature is between minus 13 ℃ and minus 10 ℃, controlling t2=7 min;

T _1y when the temperature is between minus 17 ℃ and minus 14 ℃, controlling t2=8 min;

T _1y when the temperature is between minus 21 and minus 18 ℃, controlling t2=9 min;

T _1y when the temperature is between minus 24 and minus 22 ℃, controlling t2=10 min;

T _1y when the temperature is between minus 27 and minus 25 ℃, controlling t2=11 min;

T _1y at the temperature of between-30 and-28 ℃, controlling t2=12 min.

Therefore, under the condition that the first temperature sensor fails, the first storage compartment is ensured to be sufficiently cooled, and the energy efficiency of the refrigerating system can be controlled, so that the energy consumption is saved.

Further, the control method further comprises,

when the temperature signal of the second temperature sensor cannot be obtained, judging the temperature T detected by the first temperature sensor ₁ Whether the preset starting temperature T of the first storage compartment is higher than the preset starting temperature T of the first storage compartment _{1 open} ；

If yes, the switching valve 17 is controlled to be switched to be communicated with the first cold supply branch only, and the high-temperature-stage compressor 11 is controlled to be started;

when the preset condition is met, the switching valve 17 is controlled to be switched to be communicated with the second cold supply branch only, and the low-temperature-stage compressor 22 is controlled to be started;

after a preset time t3, the low-temperature-stage compressor 22 is controlled to stop;

wherein, the preset conditions are as follows: the temperature T detected by the first temperature sensor ₁ The temperature is reduced to a preset shutdown temperature T of the first storage compartment _{1 switch} Alternatively, after a preset time t 4.

When the temperature signal of the second temperature sensor cannot be obtained, the second temperature sensor is indicated to be faulty, at the moment, the temperature in the second storage compartment cannot be monitored in real time, and the running condition of the refrigerating system can be controlled according to the temperature condition in the first storage compartment. Specifically, if the first storage compartment needs to be refrigerated, the switching valve 17 is controlled to be communicated with the first cooling branch and the high-temperature-stage compressor 11 is controlled to be started to cool the first storage compartment, until the temperature of the first storage compartment is reduced to the preset shutdown temperature, or after the preset time t4, the switching valve 17 is controlled to be communicated with the first cooling branch and the low-temperature-stage compressor 22 is controlled to be started, so that the low-temperature-stage refrigeration cycle loop 2 is enabled to cool the second storage compartment, and the situation that the second storage compartment cannot be cooled for a long time is avoided; by controlling the cooling time t2 of the second storage compartment, energy consumption can be saved. Therefore, the normal operation of the refrigerating device can be ensured under the conditions of faults, damages and the like of the second temperature sensor, so that the deterioration and decay of food materials, foods and the like stored in the refrigerating device are avoided.

Preferably, the duration of T3 is equal to the preset temperature T of the second storage compartment _2y Negative correlation, i.e. T _2y The smaller t3 is, the larger t3 is.

Specifically T _2y At the temperature of between-24 and-20 ℃, controlling t3=4 min;

T _2y at the temperature of between 29 and 25 ℃ below zero, controlling t3=5 min;

T _2y when the temperature is between minus 34 ℃ and minus 30 ℃, controlling t3=6 min;

T _2y at the temperature of between-39 and-35 ℃, controlling t3=7 min;

T _2y when the temperature is between-43 and-40 ℃, controlling t3=8 min;

T _2y at the temperature of between-47 and-44 ℃, controlling t3=9 min;

T _2y when the temperature is between minus 51 ℃ and minus 48 ℃, controlling t3=10 min;

T _2y when the temperature is between minus 54 ℃ and minus 52 ℃, controlling t3=11 min;

T _2y when the temperature is between-57 and-55 ℃, controlling t3=12 min;

T _2y at the temperature of between-60 and-58 ℃, controlling t3=13 min.

Therefore, under the condition that the second temperature sensor fails, the second storage compartment is ensured to be sufficiently cooled, and the energy efficiency of the refrigerating system can be controlled, so that the energy consumption is saved.

Preferably, t4=30 min, so as to avoid that the second storage compartment is not cooled for a long time.

Further, the control method further comprises,

after a preset time T3, if T ₁ The preset shutdown temperature T of the first storage compartment is less than or equal to the preset shutdown temperature T of the first storage compartment _{1 switch} The high temperature stage compressor 11 is controlled to stop.

That is, after controlling the cooling t3 of the second storage compartment, if the first storage compartment does not need to be cooled, the high-temperature-stage compressor 11 is controlled to stop, so as to reduce the energy consumption of the refrigeration device.

Further, the control method further comprises,

when the temperature signals of the first temperature sensor and the second temperature sensor cannot be obtained, the switching valve 17 is controlled to be switched to be communicated with the first cold supply branch only, and the high-temperature-stage compressor 11 is controlled to be started;

after a preset time t2, the switching valve 17 is controlled to be switched to be communicated with the second cold supply branch only, and the low-temperature-stage compressor 22 is controlled to be started;

after a preset time t3, the low temperature stage compression stage 22 is controlled to stop, and the high temperature stage compressor 11 is controlled to stop.

That is, when the temperature signals of the first temperature sensor and the second temperature sensor cannot be obtained, it indicates that the first temperature sensor and the second temperature sensor are both faulty, and at this time, the temperatures in the first storage compartment and the second storage compartment cannot be monitored in real time, then the switching valve 17 is controlled to be switched to be only in communication with the first cooling branch, and the high-temperature compressor 11 is controlled to be started, so that the high-temperature refrigeration cycle 1 cools the first storage compartment, and the evaporation portion 12 precools the condensation portion 21, and controls the time t2 of the high-temperature refrigeration cycle 1 cooling the first storage compartment according to the preset temperature of the first storage compartment, so that on one hand, the excessively long cooling time of the first storage compartment can be avoided, and the waste of productivity is caused, and on the other hand, the second storage compartment can be avoided from being unable to obtain the cooling time of the second storage compartment for a long time; and then, the switching valve 17 is controlled to be switched to be communicated with the second cooling branch, and the low-temperature-stage compressor 22 is controlled to be started, so that the low-temperature-stage refrigeration cycle loop 2 supplies cold to the second storage compartment, and the time t3 for the low-temperature-stage refrigeration cycle loop 2 to supply cold to the second storage compartment is controlled according to the preset temperature of the second storage compartment, thereby avoiding the excessively long cold supply time of the second storage compartment and wasting productivity.

Referring to fig. 1, further, the high-temperature-stage refrigeration cycle 1 further includes a high-temperature-stage condenser 14 provided between the high-temperature-stage compressor 11 and the switching valve 17.

Further, the high-temperature-stage refrigeration cycle 1 further includes a high-temperature-stage air return pipe 13 disposed between the high-temperature-stage compressor 11 and the evaporation portion 12, and the first refrigerant flowing through the first throttling device 161 and the second throttling device 162 exchanges heat with the first refrigerant flowing through the high-temperature-stage air return pipe 13, so that the first refrigerant in the high-temperature-stage air return pipe 13 can be used for cooling the first refrigerant in the first throttling device 161 and the second throttling device 162, increasing the refrigerating capacity, increasing the suction temperature of the high-temperature-stage compressor 11, increasing the temperature of the high-temperature-stage compressor 11 to about Wen Zuo, increasing the refrigerating efficiency of the high-temperature-stage compressor 11, and increasing the working efficiency of the high-temperature-stage refrigeration cycle 1, so that the first storage compartment can realize a temperature range of-30 to 10 ℃.

Preferably, the first throttling means 161 and the second throttling means 162 are capillary tubes.

The high-temperature-stage muffler 13 is respectively and thermally connected with the first throttling device 161 and the second throttling device 162 in a mutually sleeved or abutting mode, so that the heat exchange efficiency of the first refrigerant flowing in the first throttling device and the second throttling device is facilitated, and the energy utilization rate is improved.

Further, the high-temperature-stage refrigeration cycle 1 further includes a high-temperature-stage dry filter 18 provided between the high-temperature-stage condenser 14 and the parallel branch, and a liquid-storage bag 19 provided between the evaporation portion 12 and the high-temperature-stage muffler 13.

The low-temperature-stage refrigeration cycle 2 further includes a low-temperature-stage evaporator 24 provided between the low-temperature-stage throttle device 23 and the low-temperature-stage compressor 22.

Further, the low-temperature-stage refrigeration cycle 2 further includes a low-temperature-stage throttling device 23 and a first return air pipe section 25, and the condensing portion 21 is provided between the low-temperature-stage compressor 22 and the low-temperature-stage throttling device 23.

Further, the second refrigerant flowing through the first air return pipe section 25 exchanges heat with the second refrigerant flowing through the low-temperature-stage throttling device 23, so that the second refrigerant flowing through the first air return pipe section 25 can absorb heat of the second refrigerant flowing through the low-temperature-stage throttling device 23, the temperature of the second refrigerant flowing to the suction inlet of the low-temperature-stage compressor 22 is increased, the suction temperature of the low-temperature-stage compressor 22 is increased, the energy utilization rate of the low-temperature-stage refrigeration cycle 2 is increased, and the energy efficiency of the whole refrigeration device is improved.

Preferably, the low-temperature-stage throttling device 23 is a capillary tube, and the first air return pipe section 25 and the low-temperature-stage throttling device 23 are mutually sleeved or abutted, so that the heat exchange efficiency of the second refrigerant flowing in the two is facilitated, and the energy utilization rate is improved.

Further, the low-temperature-stage refrigeration cycle 2 further includes a second air return pipe section 26 and a heat release pipe section 27, the second air return pipe section 26 is provided between the low-temperature-stage evaporator 24 and the low-temperature-stage compressor 22, the heat release pipe section 27 is provided between the low-temperature-stage compressor 22 and the condensing portion 21, and the second refrigerant flowing through the second air return pipe section 26 exchanges heat with the second refrigerant flowing through the heat release pipe section 27. Therefore, the second refrigerant flowing through the second air return pipe section 26 can absorb the heat of the second refrigerant flowing through the heat release pipe section 27, the suction temperature of the low-temperature-stage compressor 22 is increased, the cold energy of the second refrigerant flowing from the heat release pipe section 27 to the condensation part 21 is reduced, the low-temperature-stage refrigeration cycle 2 can achieve lower temperature, the temperature of the second storage compartment can be adjusted within the temperature range of-60 to-20 ℃, the energy utilization rate of the low-temperature-stage refrigeration cycle 2 is increased, and the energy efficiency of the whole refrigeration device is improved.

Preferably, the second return air pipe section 26 is located between the first return air pipe section 25 and the low temperature stage compressor 22, so that the energy utilization rate of the low temperature stage refrigeration cycle 2 can be maximally improved.

The second air return pipe section 26 and the heat release pipe section 27 are mutually sleeved or abutted, so that the heat exchange efficiency of the second refrigerant flowing in the two is facilitated, and the energy utilization rate is improved.

Further, the low-temperature-stage refrigeration cycle 2 further includes a low-temperature-stage radiating pipe 28 provided between the low-temperature-stage compressor 22 and the radiator pipe section 27, and a low-temperature-stage drier-filter 29 provided between the condensing portion 21 and the low-temperature-stage throttling device 23. The second refrigerant flowing out of the low-temperature stage compressor 22 can be radiated by the low-temperature stage radiating pipe 28, so that the low-temperature stage refrigeration cycle 2 can achieve a lower temperature; the second refrigerant flowing out of the condensation unit 21 can be dried and filtered by the low-temperature-stage dry filter 29.

Example 2

Referring to fig. 2, a second embodiment of the present invention is shown, which differs from example 1 only in that:

the parallel branch further comprises a third throttling device 163 arranged in parallel with the second throttling device 162, and the switching valve 17 is selectively communicated with at least one of the first cooling branch, the second cooling branch and the third throttling device 163. In addition, the first refrigerant flowing through the third throttling device 163 does not exchange heat with the first refrigerant flowing through the high-temperature-stage muffler 13.

In this way, when the low-temperature-stage compressor 22 is started, the first refrigerant can flow through the third throttling device 163, and compared with the first refrigerant flowing through the second throttling device 162, the starting pressure of the refrigerating system at the moment when the low-temperature-stage compressor 22 is started can be further reduced, and the reduction of the flow rate of the first refrigerant in the second throttling device 162 caused by the heat exchange between the first refrigerant flowing into the high-temperature-stage muffler 13 and the second throttling device 162 can be avoided.

Preferably, the third throttling means 163 is a capillary tube.

The second embodiment is identical to the embodiment 1 except for the differences described above, and will not be described again here.

Compared with the prior art, the refrigerating device and the control method of the refrigerating device have the beneficial effects that: when the first refrigerant circulates in the high-temperature-stage refrigeration cycle 1, the high-temperature-stage evaporator 15 cools the first storage compartment; the second refrigerant flowing through the condensation part 21 exchanges heat with the first refrigerant flowing through the evaporation part 12, so that the first refrigerant in the evaporation part 12 can absorb heat of the second refrigerant flowing through the condensation part 21, the temperature of the second refrigerant in the condensation part 21 can be further reduced, the low-temperature-stage refrigeration cycle 2 is precooled, and the low-temperature-stage refrigeration cycle 2 can realize lower temperature; when the temperature signal of the first temperature sensor cannot be obtained, the first temperature sensor is indicated to be faulty, at the moment, the temperature in the first storage compartment cannot be monitored in real time, and the running condition of the refrigerating system can be controlled according to the temperature condition in the second storage compartment. Specifically, if the second storage compartment needs to be refrigerated, the switching valve 17 is controlled to be switched to be communicated with only the second cooling branch, the high-temperature-stage compressor 11 is controlled to be started to pre-cool the condensing portion 21, and after a preset time t1, the low-temperature-stage compressor 22 is controlled to be started to enable the low-temperature-stage refrigeration cycle 2 to cool the second storage compartment; when the temperature in the second storage compartment is reduced to the preset shutdown temperature, the low-temperature-stage compressor 22 is controlled to be shut down so as to save energy consumption, and the switching valve 17 is switched to be communicated with only the first cooling branch, and the high-temperature-stage compressor 11 is still running at this time, so that the first storage compartment can be cooled, and the energy consumption can be saved by controlling the cooling time t2 of the first storage compartment. Therefore, the normal operation of the refrigerating device can be ensured under the conditions of fault, damage and the like of the temperature sensor, so that the deterioration and decay of food materials, foods and the like stored in the refrigerating device are avoided.

It should be understood that although the present disclosure describes embodiments, not every embodiment is provided with a separate embodiment, and that this description is for clarity only, and that the skilled artisan should recognize that the embodiments may be combined as appropriate to form other embodiments that will be understood by those skilled in the art.

The above list of detailed descriptions is only specific to practical embodiments of the present invention, and they are not intended to limit the scope of the present invention, and all equivalent embodiments or modifications that do not depart from the spirit of the present invention should be included in the scope of the present invention.

Claims (12)

1. A refrigerating device is characterized by comprising,

the high-temperature-stage refrigeration cycle loop comprises a high-temperature-stage compressor, a switching valve, a parallel branch and an evaporation part, wherein a first refrigerant circulates in the high-temperature-stage refrigeration cycle loop, the parallel branch comprises a first cooling branch and a second cooling branch which are arranged in parallel, the first cooling branch comprises a first throttling device and a high-temperature-stage evaporator which are arranged in series, the second cooling branch comprises a second throttling device, and the switching valve is selectively communicated with at least one of the first cooling branch and the second cooling branch;

The low-temperature-stage refrigeration cycle loop comprises a low-temperature-stage compressor and a condensation part, wherein a second refrigerant flows in the low-temperature-stage refrigeration cycle loop, and the second refrigerant flowing through the condensation part exchanges heat with the first refrigerant flowing through the evaporation part;

the refrigerator comprises a refrigerator body, a first storage compartment and a second storage compartment, wherein the refrigerator body is provided with a high-temperature-level refrigeration cycle loop for cooling the first storage compartment, a low-temperature-level refrigeration cycle loop for cooling the second storage compartment, a first temperature sensor is arranged in the first storage compartment, and a second temperature sensor is arranged in the second storage compartment;

a controller for controlling the operation of the device,

when the temperature signal of the first temperature sensor cannot be obtained, judging the temperature T detected by the second temperature sensor ₂ Whether the preset starting temperature T of the second storage compartment is higher than the preset starting temperature T of the second storage compartment _{2 open} ；

If yes, the switching valve is controlled to be switched to be communicated with the second cold supply branch only, and the high-temperature-stage compressor is controlled to be started;

after a preset time t1, controlling the low-temperature-stage compressor to start;

the temperature T detected by the second temperature sensor ₂ The temperature is reduced to a preset shutdown temperature T of the second storage compartment _{2-pass valve} When the low-temperature-stage compressor is controlled to stop, the switching valve is controlled to be switched to be communicated with the first cold supply branch only;

after a preset time T2, judging T ₂ Whether the preset starting temperature T of the second storage compartment is higher than the preset starting temperature T of the second storage compartment _{2 open} ；

If not, controlling the high-temperature-stage compressor to stop.

2. The refrigeration unit of claim 1 wherein said controller is further configured to,

after a preset time T2, if T ₂ >T _{2 open} And controlling the switching valve to be switched to be communicated with the second cold supply branch only, and controlling the low-temperature-stage compressor to start.

3. The refrigeration unit of claim 1 wherein said controller is further configured to,

when the temperature signal of the second temperature sensor cannot be obtained, judging the temperature T detected by the first temperature sensor ₁ Whether the preset starting temperature T of the first storage compartment is higher than the preset starting temperature T of the first storage compartment _{1 open} ；

If yes, the switching valve is controlled to be switched to be communicated with the first cold supply branch only, and the high-temperature-stage compressor is controlled to be started;

when a preset condition is met, the switching valve is controlled to be switched to be communicated with the second cold supply branch only, and the low-temperature-stage compressor is controlled to be started;

After a preset time t3, controlling the low-temperature-stage compressor to stop;

wherein, the preset conditions are as follows: the temperature T detected by the first temperature sensor ₁ The temperature is reduced to a preset shutdown temperature T of the first storage compartment _{1 switch} Alternatively, after a preset time t 4.

4. A refrigeration device according to claim 3 wherein the controller is further configured to,

after a preset time T3, if T ₁ The preset shutdown temperature T of the first storage compartment is less than or equal to the preset shutdown temperature T of the first storage compartment _{1 switch} And controlling the high-temperature-stage compressor to stop.

5. The refrigeration unit of claim 1 wherein said controller is further configured to,

when the temperature signals of the first temperature sensor and the second temperature sensor cannot be obtained, the switching valve is controlled to be switched to be communicated with the first cold supply branch only, and the high-temperature-stage compressor is controlled to be started;

after a preset time t2, controlling the switching valve to be switched to be communicated with the second cold supply branch only, and controlling the low-temperature-stage compressor to start;

and after a preset time t3, controlling the low-temperature-stage compression stage to stop, and controlling the high-temperature-stage compressor to stop.

6. A refrigerating apparatus as recited in any one of claims 1 to 5, wherein,

The preset temperature T of the first storage compartment _1y When the temperature is between 6 and 10 ℃, controlling t2=3 min;

T _1y when the temperature is between 1 and 5 ℃, controlling t2=4 min;

T _1y when the temperature is between 4 ℃ below zero and 0 ℃, controlling t2=5 min;

T _1y when the temperature is between minus 9 and minus 5 ℃, controlling t2=6 min;

T _1y when the temperature is between minus 13 ℃ and minus 10 ℃, controlling t2=7 min;

T _1y when the temperature is between minus 17 ℃ and minus 14 ℃, controlling t2=8 min;

T _1y when the temperature is between minus 21 and minus 18 ℃, controlling t2=9 min;

T _1y when the temperature is between minus 24 and minus 22 ℃, controlling t2=10 min;

T _1y when the temperature is between minus 27 and minus 25 ℃, controlling t2=11 min;

T _1y at the temperature of between-30 and-28 ℃, controlling t2=12 min.

7. A refrigerating apparatus as recited in any one of claims 3 to 5, wherein,

the preset temperature T of the second storage compartment _2y At the temperature of between-24 and-20 ℃, controlling t3=4 min;

T _2y at the temperature of between 29 and 25 ℃ below zero, controlling t3=5 min;

T _2y when the temperature is between minus 34 ℃ and minus 30 ℃, controlling t3=6 min;

T _2y at the temperature of between minus 39 and minus 35 DEG CT3=7 min;

T _2y when the temperature is between-43 and-40 ℃, controlling t3=8 min;

T _2y at the temperature of between-47 and-44 ℃, controlling t3=9 min;

T _2y when the temperature is between minus 51 ℃ and minus 48 ℃, controlling t3=10 min;

T _2y when the temperature is between minus 54 ℃ and minus 52 ℃, controlling t3=11 min;

T _2y when the temperature is between-57 and-55 ℃, controlling t3=12 min;

T _2y at the temperature of between-60 and-58 ℃, controlling t3=13 min.

8. A control method of a refrigeration apparatus according to claim 1, wherein the control method comprises,

When the temperature signal of the first temperature sensor cannot be obtained, the switching valve is controlled to be switched to be communicated with the second cold supply branch only, and the high-temperature-stage compressor is controlled to be started;

after a preset time t1, controlling the low-temperature-stage compressor to start;

the temperature T detected by the second temperature sensor ₂ The temperature is reduced to a preset shutdown temperature T of the second storage compartment _{2-pass valve} When the low-temperature-stage compressor is controlled to stop, the switching valve is controlled to be switched to be communicated with the first cold supply branch only;

after a preset time T2, judging T ₂ Whether the preset starting temperature T of the second storage compartment is higher than the preset starting temperature T of the second storage compartment _{2 open} ；

If not, controlling the high-temperature-stage compressor to stop.

9. A control method of a refrigeration apparatus according to claim 8, wherein said control method further comprises,

after a preset time T2, if T ₂ >T _{2 open} And controlling the switching valve to be switched to be communicated with the second cold supply branch only, and controlling the low-temperature-stage compressor to start.

10. A control method of a refrigeration apparatus according to claim 8, wherein said control method further comprises,

when the temperature signal of the second temperature sensor cannot be obtained, the switching valve is controlled to be switched to be communicated with the first cold supply branch only, and the high-temperature-stage compressor is controlled to be started;

When a preset condition is met, the switching valve is controlled to be switched to be communicated with the second cold supply branch only, and the low-temperature-stage compressor is controlled to be started;

after a preset time t3, controlling the low-temperature-stage compressor to stop;

wherein, the preset conditions are as follows: the temperature T detected by the first temperature sensor ₁ The temperature is reduced to a preset shutdown temperature T of the first storage compartment _{1 switch} Alternatively, after a preset time t 4.

11. A control method of a refrigeration unit as recited in claim 10, wherein said control method further comprises,

after a preset time T3, if T ₁ The preset shutdown temperature T of the first storage compartment is less than or equal to the preset shutdown temperature T of the first storage compartment _{1 switch} And controlling the high-temperature-stage compressor to stop.

12. A control method of a refrigeration apparatus according to claim 8, wherein said control method further comprises,

when the temperature signals of the first temperature sensor and the second temperature sensor cannot be obtained, the switching valve is controlled to be switched to be communicated with the first cold supply branch only, and the high-temperature-stage compressor is controlled to be started;

after a preset time t2, controlling the switching valve to be switched to be communicated with the second cold supply branch only, and controlling the low-temperature-stage compressor to start;

And after a preset time t3, controlling the low-temperature-stage compression stage to stop, and controlling the high-temperature-stage compressor to stop.