Control methods for refrigeration equipment and refrigeration equipment

Abstract

This invention provides a control method for a refrigeration device and the refrigeration device itself. The control method includes: acquiring the highest temperature Tg and the lowest temperature Td of the refrigeration chamber within one cycle of the initial operating phase of the variable frequency compressor; determining that the difference between the highest temperature Tg and the lowest temperature Td is greater than a first preset threshold Tp, then controlling the variable frequency compressor to execute a frequency adjustment program and obtain the adjusted operating frequency Fb; then controlling the variable frequency compressor to execute a trial run program at Fb, obtaining the first running time t1 and the shutdown time t of the variable frequency compressor; then controlling the variable frequency compressor to execute a normal operation program, in which the variable frequency compressor is controlled to execute the operating phase at the operating frequency Fb and the first running time t1, and then the variable frequency compressor is stopped and remains stopped for a duration t to execute the shutdown phase. Through the above control method, the refrigeration device automatically adjusts the operating frequency of the variable frequency compressor, reducing temperature fluctuations within the refrigeration chamber and improving the user experience.

Description

Technical Field

[0001] This invention relates to the field of refrigeration technology, and in particular to a control method for refrigeration equipment and refrigeration equipment. Background Technology

[0002] With the continuous development of refrigeration technology, especially the increasingly widespread application of cold storage systems equipped with variable frequency compressors in food storage, the temperature inside the refrigerated compartments of cold storage is currently determined by the cooling capacity, evaporation temperature, and condensation temperature of the variable frequency compressor. However, the operation of current refrigeration systems does not yet consider the temperature fluctuations within the refrigerated compartments. During food storage, the magnitude of temperature fluctuations affects the weight loss rate, pH value, color difference, texture, and other qualities of the food. Therefore, reducing temperature fluctuations within the refrigerated compartments during food storage is beneficial for improving the quality of stored food.

[0003] Therefore, a new control method for refrigeration equipment is needed to solve the problem of large temperature fluctuations in the refrigeration room. Summary of the Invention

[0004] This invention provides a control method and a refrigeration device to solve one of the above-mentioned problems, thereby reducing temperature fluctuations in the storage and refrigeration room and improving the quality of food in the storage and refrigeration room.

[0005] To achieve the above objectives, the technical solution provided by the present invention is as follows:

[0006] A control method for a refrigeration device, the control method comprising the following steps:

[0007] Obtain the highest temperature Tg and lowest temperature Td of the refrigeration chamber during one cycle of the initial working stage of the variable frequency compressor;

[0008] Determine whether the difference between the highest temperature Tg and the lowest temperature Td is less than a first preset threshold Tp.

[0009] If not, the variable frequency compressor is controlled to execute a frequency adjustment program, and the operating frequency Fb of the variable frequency compressor after frequency adjustment is obtained through the frequency adjustment program;

[0010] The variable frequency compressor is controlled to execute a trial operation program at the operating frequency Fb. The first running time t1 when the variable frequency compressor is in the working stage and the shutdown time t when it is in the shutdown stage are obtained through the trial operation program.

[0011] The variable frequency compressor is controlled to execute a normal operation procedure, which includes controlling the variable frequency compressor to perform a work cycle at an operating frequency Fb and a first operating time t1, and then the variable frequency compressor stops and remains stopped for a duration t.

[0012] Furthermore, the frequency adjustment program includes: acquiring the cooling capacity Qa and the enthalpy difference of the refrigerant from the highest temperature Tg to the lowest temperature Td within the initial working cycle of the variable frequency compressor;

[0013] The compressor operating frequency Fb is obtained based on the cooling capacity Qa and the enthalpy difference of the refrigerant.

[0014] Furthermore, the frequency modulation program also includes: obtaining the preset target temperature T0 of the cooling room, and preset the first monitoring temperature T1 and the second monitoring temperature T2, so that the temperature difference between T1 and T0 is equal to the temperature difference between T0 and T2.

[0015] When the compressor is in the shutdown phase, the first shutdown time t2 is obtained, which is the time it takes for the temperature of the refrigeration room to rise from the second monitoring temperature T2 to the first monitoring temperature T1.

[0016] Furthermore, after the variable frequency compressor executes the frequency adjustment program, when the variable frequency compressor continues to be stopped for the initial shutdown duration t0, the variable frequency compressor is controlled to execute the trial operation program.

[0017] Furthermore, after the variable frequency compressor executes the frequency adjustment program, when the real-time temperature Ti in the refrigeration room is detected to reach the first monitoring temperature T1, the variable frequency compressor is controlled to execute the trial operation program.

[0018] Furthermore, the trial operation procedure includes:

[0019] The variable frequency compressor is controlled to operate at the operating frequency Fb. The time taken for the indoor temperature of the refrigeration room to drop from the first monitoring temperature T1 to the second monitoring temperature T2 is the first operating time t1. Then, the variable frequency compressor is controlled to stop.

[0020] Furthermore, the trial operation procedure also includes:

[0021] When the variable frequency compressor stops and continues to stop for the first duration t2, the real-time temperature Ti in the refrigeration room is detected, and it is determined whether Ti has reached the first monitoring temperature T1.

[0022] If so, then the first downtime t2 is the downtime t;

[0023] If not, then the variable frequency compressor continues to shut down for a second shutdown duration t3 until the real-time temperature Ti in the refrigeration room reaches the first monitoring temperature T1; then t2+t3 is the shutdown duration t.

[0024] Further, it is determined whether the difference between the highest temperature Tg and the lowest temperature Td is less than the first preset threshold Tp; if so, the compressor is controlled to maintain the initial operating frequency F0.

[0025] The present invention also relates to a refrigeration device, including a refrigeration compartment and a refrigeration system for providing cooling capacity to the refrigeration compartment, wherein the refrigeration system includes a variable frequency compressor and a control unit, the control unit including a memory and a processor, the memory storing a computer program that can run on the processor, and the processor executing the computer program to implement the steps of the above-described control method for the refrigeration device.

[0026] Furthermore, the refrigeration equipment also includes a temperature sensor for detecting the real-time temperature Ti inside the refrigeration room.

[0027] Compared with the prior art, the beneficial effects of the present invention are as follows: The control method of the refrigeration equipment of the present invention automatically adjusts the operating frequency of the variable frequency compressor by means of the refrigeration capacity and the enthalpy difference of the refrigerant, reduces the temperature fluctuation in the refrigeration room, provides a near constant temperature storage environment, which is conducive to improving the storage quality of food and enhancing the user experience. Attached Figure Description

[0028] Figure 1 This is a flowchart illustrating an embodiment of the control method for the refrigeration equipment of the present invention.

[0029] Figure 2 yes Figure 1 The figure shows a curve of the temperature change in the refrigeration room over time in the embodiment.

[0030] Figure 3 This is a flowchart illustrating another embodiment of the control method for the refrigeration equipment of the present invention.

[0031] 1-Initial working cycle, 2-Frequency adjustment working cycle, 3-Trial operation working cycle, 4-Normal working cycle. Detailed Implementation

[0032] To enable those skilled in the art to better understand the technical solutions of this invention, the technical solutions of the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this invention.

[0033] This invention provides a control method for refrigeration equipment and the refrigeration equipment itself. The control method is implemented based on the refrigeration equipment provided by this invention. The refrigeration equipment includes a refrigeration compartment and a refrigeration system for providing cooling capacity to the refrigeration compartment. In the case of refrigeration equipment, cold storage facilities often have large volumes, leading to significant temperature fluctuations within the refrigeration compartment. Therefore, the refrigeration equipment and its control method of this invention are suitable for cold storage facilities with large refrigeration compartment volumes, including refrigerated and frozen storage facilities.

[0034] Generally, the working cycle of the variable frequency compressor includes a working phase and a shutdown phase. During the working phase, the variable frequency compressor starts and provides cooling to the refrigeration room. After the compressor has been running continuously for a set time or the temperature in the storage room has dropped to a preset temperature, the compressor stops and continues to shut down for the preset shutdown time or until the temperature in the storage room rises to the preset temperature, completing one working cycle. Then, the compressor restarts to provide cooling to the refrigeration room to lower its temperature. The control method of the refrigeration equipment of this invention is suitable for situations where the temperature in the refrigeration room fluctuates significantly within one working cycle of the variable frequency compressor.

[0035] Based on the structure of the refrigeration equipment, the control method of the refrigeration equipment of the present invention includes the following steps: Figures 1 to 3 As shown, the highest temperature Tg and lowest temperature Td of the refrigeration chamber are acquired within one working cycle of the variable frequency compressor during the initial working phase. It is determined whether the difference between the highest temperature Tg and the lowest temperature Td is less than a first preset threshold Tp. If so, it indicates that the temperature fluctuation within the refrigeration chamber is within an acceptable range. The variable frequency compressor is then controlled to maintain its initial operating frequency F0 for the next working cycle. While the variable frequency compressor is in the next working cycle, the highest temperature Tg and lowest temperature Td of the refrigeration chamber are acquired again, and their difference is compared with the first preset threshold Tp. This working cycle is the initial working cycle 1. Figure 2 As shown, within this working cycle, the frequency of the variable frequency compressor is the initial working frequency F0, the duration of the working phase is the initial working duration t′, and the duration of the shutdown phase is the initial shutdown duration t0.

[0036] Accordingly, it is determined whether the difference between the highest temperature Tg and the lowest temperature Td is less than the first preset threshold Tp. If not, it indicates that the temperature fluctuation in the refrigeration room is relatively large and exceeds the acceptable range. Then, the variable frequency compressor is controlled to execute a frequency adjustment program. The frequency adjustment program obtains the operating frequency Fb of the variable frequency compressor after frequency adjustment, wherein the operating frequency Fb is greater than the initial operating frequency F0. This increases the cooling capacity of the refrigeration system per unit time. That is, under the premise of constant cooling capacity, the cooling efficiency of the compressor is improved, the working time of the variable frequency compressor is shortened, and the temperature in the refrigeration room is reduced. As a result, the difference between the highest temperature Tg and the lowest temperature Td in one working cycle of the variable frequency compressor is reduced, and the temperature fluctuation range in the refrigeration room is within an acceptable range, providing a more stable storage environment for food.

[0037] The frequency regulation program is one working cycle of the variable frequency compressor, referred to as frequency regulation working cycle 2, such as... Figure 2 As shown, the working cycle of the frequency modulation program includes the working stage and the shutdown stage of the variable frequency compressor. In a preferred embodiment of the control method of the present invention, the frequency modulation program includes: obtaining the cooling capacity Qa between the highest temperature Tg and the lowest temperature Td during the initial working cycle of the variable frequency compressor, wherein the cooling capacity Qa can be obtained based on the parameters of the variable frequency compressor, and the cooling capacity Qa of the compressor remains constant in each working cycle.

[0038] Furthermore, the compressor operating frequency Fb is obtained based on the cooling capacity Qa and the enthalpy difference of the refrigerant. Specifically, the refrigerant flow rate is obtained based on the cooling capacity Qa and the enthalpy difference. The refrigerant flow rate is combined with the discharge capacity of the variable frequency compressor to obtain the speed of the variable frequency compressor, thus obtaining the operating frequency Fb of the variable frequency compressor. The enthalpy difference of the refrigerant is obtained through the compressor parameters and the evaporation temperature and condensation temperature of the refrigerant.

[0039] During the execution of the frequency adjustment program, it is also necessary to obtain the preset target temperature T0 of the refrigeration room, and preset the first monitoring temperature T1 and the second monitoring temperature T2, so that the temperature difference between T1 and T0 is equal to the temperature difference between T0 and T2. That is, the first monitoring temperature T1 and the second monitoring temperature T2 are the pre-set acceptable temperature fluctuation ranges, which serve as temperature references for subsequent working cycles, so that the highest temperature in the storage room is T1 and the lowest temperature is T2 in the next working cycle after the frequency converter is adjusted.

[0040] Once the real-time temperature Ti inside the storage room drops to the minimum temperature Td or the variable frequency compressor has been in operation for the initial working time t′, the variable frequency compressor is controlled to stop, causing it to enter the shutdown phase.

[0041] When the compressor is in the shutdown phase, the first shutdown duration t2 taken for the refrigeration room temperature to rise from the second monitoring temperature T2 to the first monitoring temperature T1 continues to be acquired, such as... Figure 2 As shown, during the shutdown phase, the time corresponding to the second monitored temperature T2 is ta, and the time corresponding to the first monitored temperature T1 is tb. Therefore, the first shutdown duration t2 is the time difference obtained by subtracting ta from tb. The first shutdown duration t2 is tentatively set as the duration of the shutdown phase within the first working cycle after the variable frequency compressor is frequency-converted. It can be appropriately adjusted based on the actual situation on the basis of the first shutdown duration t2.

[0042] In this embodiment, when the variable frequency compressor is in the frequency adjustment program working stage, the variable frequency compressor operates at the initial operating frequency F0.

[0043] When the variable frequency compressor is in the shutdown stage and continues for an initial shutdown time t0, the variable frequency compressor is controlled to execute the trial operation program, that is, the variable frequency compressor ends the frequency adjustment working cycle 2, and then the variable frequency compressor is controlled to enter the next working cycle.

[0044] Of course, the standard for determining when the variable frequency compressor ends the frequency regulation program can also be: the temperature sensor detects that the real-time temperature Ti in the refrigeration room reaches the first monitoring temperature T1, and then the variable frequency compressor is controlled to execute the trial operation program.

[0045] Because the cooling capacity provided by the variable frequency compressor has a certain delay in reaching the preset temperature in the cooling room, that is, after the variable frequency compressor is in operation and has been operating for a certain period of time, the cooling capacity provided by the variable frequency compressor is sufficient to meet the cooling needs of the cooling room, but the temperature in the cooling room needs to be maintained for a certain period of time to reach the preset temperature. In order to avoid wasting the cooling capacity in the cooling room, the preferred embodiment uses the operating time and shutdown time of the variable frequency compressor as the standard for controlling the start-up or shutdown of the variable frequency compressor.

[0046] Similarly, the trial operation procedure also consists of one work cycle, which is called trial operation work cycle 3, such as... Figure 2 As shown, the variable frequency compressor is in both a working phase and a shutdown phase. During the trial run, the variable frequency compressor operates at a frequency Fb during the working phase, and the trial run program obtains the first operating time t1 when the compressor is in the working phase and the shutdown time t when it is in the shutdown phase.

[0047] Specifically, in combination Figure 2 and Figure 3As shown, during the process of controlling the variable frequency compressor to perform the working phase at the operating frequency Fb, the time taken for the indoor temperature of the refrigeration room to drop from the first monitored temperature T1 to the second monitored temperature T2 is obtained as the first operating time t1. Then, the variable frequency compressor is controlled to stop. Figure 2 As shown, the first running time t1 is the time difference obtained by subtracting tc from td, where the first running time t1 is the continuous working time required for the variable frequency compressor to be in the working stage in the next working cycle.

[0048] like Figure 3 As shown, the specific process for obtaining the shutdown duration t is as follows: when the variable frequency compressor stops and continues for the first shutdown duration t2, the real-time temperature Ti in the refrigeration room is obtained through the temperature sensor, and it is determined whether the real-time temperature Ti has reached the first monitoring temperature T1, that is, whether the real-time temperature Ti in the refrigeration room has risen to the highest acceptable temperature. If so, the first shutdown duration t2 is the shutdown duration t, the trial operation program ends, and the variable frequency compressor is controlled to start to enter the next working cycle.

[0049] If not, then the variable frequency compressor continues to shut down for a second shutdown duration t3 until the real-time temperature Ti in the refrigeration room reaches the first monitoring temperature T1; then, t2+t3 is the shutdown duration t, which is the time required for the temperature in the refrigeration room to rise from the second monitoring temperature T2 to the first monitoring temperature T1. Figure 2 As shown, the variable frequency compressor stops at the second monitoring temperature T2 at time td, and stops at the first monitoring temperature T1 at time te. Then, the stop time t is the time difference obtained by subtracting td from te. Then, the trial run program ends and the variable frequency compressor is controlled to start up to enter the next working cycle.

[0050] Furthermore, after the trial run is completed, the variable frequency compressor is controlled to execute the normal operation program, referred to as normal operation cycle 4, such as... Figure 2 As shown, the normal operation procedure includes controlling the variable frequency compressor to run at a frequency Fb for a first running time t1 to perform a working phase, so as to reduce the real-time temperature Ti in the refrigeration room from the highest temperature T1 to the lowest temperature T2. Then, the variable frequency compressor is controlled to stop and the stop phase is completed for a continuous stop time t. Then, the variable frequency compressor is controlled to restart and repeat the next working cycle with the parameters of the normal operation procedure.

[0051] The working process of the control method of the refrigeration equipment of the present invention is as follows: the difference between the highest temperature Tg and the lowest temperature Td of the refrigeration chamber in the initial working cycle 1 is determined. If the difference exceeds the first preset threshold Tp, the variable frequency compressor is controlled to enter the frequency adjustment working cycle 2 to execute the frequency adjustment program, thereby obtaining the working frequency Fb of the variable frequency compressor after frequency adjustment and the first shutdown duration t2. Then, the trial operation working cycle 3 is entered to execute the trial operation program to obtain the first running duration t1 and the shutdown duration t. Then, the variable frequency compressor is controlled to enter the normal operation working cycle 4 with the operating frequency Fb and the first running duration t1 to execute the working stage in the normal operation program. Then, the compressor is controlled to shut down and remain shut for a continuous shutdown duration t to complete the shutdown stage. Then, the variable frequency compressor is controlled to enter the next normal operation program working cycle.

[0052] The present invention also relates to a refrigeration device, the refrigeration device including a refrigeration compartment and a refrigeration system for providing cooling capacity to the refrigeration compartment, the refrigeration system including a variable frequency compressor and a control unit for controlling the operation of the variable frequency compressor, the control unit including a memory and a processor, the memory storing a computer program that can run on the processor, the processor executing the computer program to implement the steps of the control method of the refrigeration device of the present invention, so as to realize that the variable frequency compressor automatically adjusts the frequency of the variable frequency compressor according to the temperature of the refrigeration compartment, so as to reduce the temperature fluctuation in the storage compartment.

[0053] Furthermore, the refrigeration equipment also includes a temperature sensor for detecting the real-time temperature Ti inside the refrigeration room. The temperature sensor is communicatively connected to the control unit, and the temperature sensor transmits the real-time temperature Ti information inside the refrigeration room to the control unit.

[0054] In summary, the control method and refrigeration equipment of the present invention can automatically adjust the operating frequency of the variable frequency compressor according to the refrigeration capacity and the enthalpy difference of the refrigerant, reduce temperature fluctuations in the refrigeration room, provide a near-constant temperature storage environment, improve the storage quality of food, and enhance the user experience.

[0055] It should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This way of describing the specification is only for clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

[0056] The detailed descriptions listed above are merely specific illustrations of feasible embodiments of the present invention and are not intended to limit the scope of protection of the present invention. All equivalent embodiments or modifications made without departing from the spirit of the present invention should be included within the scope of protection of the present invention.

Claims

1. A control method for a cold storage facility, characterized in that: Includes the following steps: Obtain the highest temperature Tg and lowest temperature Td of the refrigeration chamber during one cycle of the initial working stage of the variable frequency compressor; Determine whether the difference between the highest temperature Tg and the lowest temperature Td is less than a first preset threshold Tp. If so, then control the compressor to maintain its initial operating frequency F0. If not, the variable frequency compressor is controlled to execute a frequency adjustment program to obtain the cooling capacity Qa and the enthalpy difference of the refrigerant from the highest temperature Tg to the lowest temperature Td within the initial working cycle of the variable frequency compressor. Based on the cooling capacity Qa and the enthalpy difference of the refrigerant, the compressor operating frequency Fb is obtained, and the operating frequency Fb is greater than the initial operating frequency F0. Obtain the preset target temperature T0 of the cooling room, and preset the first monitoring temperature T1 and the second monitoring temperature T2, so that the temperature difference between T1 and T0 is equal to the temperature difference between T0 and T2. The variable frequency compressor is controlled to execute a trial operation program at the operating frequency Fb. The time taken for the indoor temperature of the refrigeration room to drop from the first monitoring temperature T1 to the second monitoring temperature T2 is obtained through the trial operation program as the first running time t1. Then the variable frequency compressor is controlled to stop. When the compressor is in the shutdown phase, the first shutdown duration t2 is obtained, which is the time it takes for the temperature of the refrigeration room to rise from the second monitoring temperature T2 to the first monitoring temperature T1. When the variable frequency compressor stops and continues to stop for the first duration t2, the real-time temperature Ti in the refrigeration room is detected, and it is determined whether Ti has reached the first monitoring temperature T1. If so, then the first downtime t2 is the downtime t; If not, then the variable frequency compressor continues to shut down for a second shutdown duration t3 until the real-time temperature Ti in the refrigeration room reaches the first monitoring temperature T1; then, t2+t3 is the shutdown duration t. The variable frequency compressor is controlled to execute a normal operation procedure, which includes controlling the variable frequency compressor to perform a work cycle at an operating frequency Fb and a first operating time t1, and then the variable frequency compressor stops and remains stopped for a duration t.

2. The cold storage control method as described in claim 1, characterized in that: After the variable frequency compressor executes the frequency adjustment program, when the variable frequency compressor stops for the initial shutdown duration t0, the variable frequency compressor is controlled to execute the trial operation program.

3. The cold storage control method as described in claim 1, characterized in that: After the variable frequency compressor executes the frequency adjustment program, when the real-time temperature Ti in the refrigeration room is detected to reach the first monitoring temperature T1, the variable frequency compressor is controlled to execute the trial operation program.

4. A cold storage facility, comprising a refrigeration compartment and a refrigeration system for providing cooling capacity to the refrigeration compartment, characterized in that: The refrigeration system includes a variable frequency compressor and a control unit. The control unit includes a memory and a processor. The memory stores a computer program that can run on the processor. When the processor executes the computer program, it implements the steps of the cold storage control method as described in any one of claims 1 to 3.

5. The cold storage facility as described in claim 4, characterized in that: The cold storage also includes a temperature sensor for detecting the real-time temperature Ti inside the refrigeration room.

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