A refrigeration equipment control method, system, refrigeration equipment and medium

Abstract

The present disclosure provides a refrigeration equipment control method, system, refrigeration equipment and medium. The method is for a fixed-frequency compressor refrigeration system, and when the refrigeration equipment enters a stable running state and is not in an energy-saving state, a target temperature control hysteresis is obtained by adjusting a current temperature control hysteresis. Finally, the starting frequency of the compressor is adjusted according to the target temperature control hysteresis. The method dynamically adjusts the temperature control hysteresis through a software algorithm, so that the compressor can run at an optimal starting frequency, and the purposes of energy saving and improving the service life of the compressor can be achieved at the same time.

Description

Technical Field

[0001] This disclosure relates to the field of energy-saving technology for freezer and refrigerator control, and in particular to a method, system, refrigeration equipment and medium for controlling refrigeration equipment. Background Technology

[0002] Currently, the main methods to reduce the operating frequency of refrigerator compressors are: adjusting the frequency of the inverter compressor and optimizing the internal airflow between different compartments of the refrigerator. However, compared to fixed-frequency compressors, inverter compressors are more expensive and more difficult to maintain. Airflow optimization is suitable for refrigerators with separate refrigeration and freezing compartments, but cannot be widely applied to single-temperature zone refrigerators.

[0003] Therefore, the problem that this disclosure aims to solve is how to provide a control method for refrigeration systems based on simple and low-cost fixed-frequency compressors that can achieve adaptive optimization of the operating cycle without changing the hardware, thereby achieving energy saving through software algorithms. Summary of the Invention

[0004] This disclosure provides a refrigeration equipment control method, system, refrigeration equipment, and medium; it can achieve adaptive optimization of the operating cycle for a fixed-frequency compressor refrigeration system through software algorithms alone, thereby achieving energy saving.

[0005] The technical solution disclosed herein is implemented as follows:

[0006] In a first aspect, this disclosure provides a method for controlling a refrigeration device, the method comprising:

[0007] When the refrigeration equipment enters a stable operating state and is not in energy-saving mode, the current temperature control hysteresis is adjusted to obtain the target temperature control hysteresis;

[0008] Adjust the compressor's start-up frequency according to the target temperature control hysteresis;

[0009] The temperature hysteresis is the difference between two temperature thresholds that control the compressor to start and stop.

[0010] Secondly, this disclosure provides a refrigeration equipment control system, which includes a controller;

[0011] The controller is configured as follows:

[0012] When the refrigeration equipment enters a stable operating state and is not in energy-saving mode, the current temperature control hysteresis is adjusted to obtain the target temperature control hysteresis;

[0013] Adjust the compressor's start-up frequency according to the target temperature control hysteresis;

[0014] Among them, temperature hysteresis is the difference between two temperature thresholds that control the start and stop of the compressor.

[0015] Thirdly, this disclosure provides a refrigeration device, which includes the refrigeration device control system described above.

[0016] Fourthly, this disclosure provides a computer-readable storage medium storing at least one instruction, which is executed by a processor to implement the cooling device control method of this disclosure.

[0017] This disclosure provides a control method, system, refrigeration equipment, and medium for refrigeration equipment. The method, targeting a fixed-frequency compressor refrigeration system, adjusts the current temperature control hysteresis to obtain a target temperature control hysteresis when the refrigeration equipment enters a stable operating state and is not in energy-saving mode. Finally, the compressor's operating frequency is adjusted based on the target temperature control hysteresis. This method dynamically adjusts the temperature control hysteresis solely through software algorithms, enabling the compressor to operate at the optimal operating frequency, simultaneously achieving energy savings and extending the compressor's lifespan. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the composition of the refrigeration equipment provided in this disclosure.

[0019] Figure 2 This is a flowchart of the refrigeration equipment control method provided in this disclosure.

[0020] Figure 3 This is a flowchart for determining whether a refrigeration device is in an energy-saving state, as provided in this disclosure.

[0021] Figure 4 This is a flowchart for adjusting the current temperature control hysteresis provided in this disclosure.

[0022] Figure 5 The diagram shows the internal temperature test results of the refrigeration equipment provided in this disclosure at DIF=1.5.

[0023] Figure 6 The diagram shows the internal temperature test results of the refrigeration equipment provided in this disclosure when DIF=2.

[0024] Figure 7 The diagram shows the internal temperature test results of the refrigeration equipment provided in this disclosure when DIF=3.

[0025] Figure 8 This is a flowchart for adjusting the speed of the evaporator fan provided in this disclosure. Detailed Implementation

[0026] The technical solutions in this disclosure will now be clearly and completely described with reference to the accompanying drawings.

[0027] Figure 1This is a schematic diagram illustrating the composition of an exemplary refrigeration device 100 disclosed herein. The refrigeration device 100 involved in this disclosure can be a refrigerator, freezer, or other device capable of storing items in a refrigerated or frozen state. Figure 1 In the refrigeration equipment 100, there is a main body 110 having a front opening, a compartment 120 formed in the main body 110 for storing items, a door 130 for opening or closing the front opening of the main body 110, and a refrigeration system 140 for cooling the temperature inside the compartment 120.

[0028] The main body 110 defines the appearance of the refrigeration device 100. Exemplarily, the main body 110 includes an inner housing 112 for forming a compartment and an outer housing 114 coupled to the outside of the inner housing 112. An insulating material is filled between the inner housing 112 and the outer housing 114 to prevent cold air from leaking from the compartment 120.

[0029] For example, compartment 120 can be implemented as a refrigerator compartment for storing items in a refrigerated state, storing items at a temperature above zero degrees Celsius. For instance, in a refrigerated state, the temperature of compartment 120 can be maintained in a temperature range of approximately 1 to 5 degrees Celsius. Furthermore, compartment 120 can also be implemented as a freezer compartment for storing items in a frozen state, storing items at a temperature below zero degrees Celsius. For instance, in a frozen state, the temperature of compartment 120 can be maintained in a temperature range of approximately -13 to -20 degrees Celsius.

[0030] The compartment 120 can be opened or closed through the door 130. After the door 130 is closed, when the temperature inside the compartment 120, which is implemented as a refrigerator compartment, is higher than the temperature range corresponding to the refrigeration state, or when the temperature inside the compartment 120, which is implemented as a freezer compartment, is higher than the temperature range corresponding to the freezing state, the refrigeration system 140 will be activated to lower the temperature inside the compartment 120.

[0031] For example, the refrigeration system 140 includes a compressor 142, a condenser 144, an expansion valve 146, and an evaporator 148. Specifically, the compressor 142 and the condenser 144 may be arranged in the machine room at the lower rear of the main body 110. Figure 1 (Not shown). The expansion valve 146 and the evaporator 148 can be disposed in the pipes (not shown) inside the main body 110. Figure 1 (Not shown)

[0032] For example, in conjunction with the components included in the above-described refrigeration system 140, the refrigeration system 140 operates in the following modes during the process of reducing the temperature within the compartment 120 to a temperature range corresponding to the refrigeration or freezing state (i.e., the refrigeration process):

[0033] First, the compressor 142 compresses the low-pressure gaseous refrigerant to form a high-pressure gaseous refrigerant, and then transmits the high-pressure gaseous refrigerant to the condenser 144 through the refrigerant pipeline 135 under high pressure.

[0034] Subsequently, the high-pressure gaseous refrigerant is condensed into a high-pressure liquid refrigerant through condenser 144, and during this condensation process, the refrigerant releases latent heat. In some examples, the condenser 144 is heated by the latent heat released from the refrigerant; therefore, a condenser fan 143 can be configured to exhaust the released latent heat to the external environment of the refrigeration equipment 100 to cool the condenser 144.

[0035] Next, the expansion valve 146 reduces the pressure of the high-pressure liquid refrigerant, and the expansion valve 146 can also adjust the amount of refrigerant so that the refrigerant can absorb sufficient heat energy from the evaporator 148. In some examples, the expansion valve 146 can be implemented as an electronic expansion valve, in which case the open or closed state of the expansion valve 146, as well as the degree of opening (hereinafter referred to as the opening degree), can be adjusted.

[0036] Finally, the evaporator 148 evaporates the depressurized liquid refrigerant, and during the evaporation process, the refrigerant absorbs latent heat from the evaporator 148 to cool the air surrounding the evaporator 148. In some examples, the refrigeration device 100 also includes an evaporator fan 149, which directs the air cooled by the evaporator 148 through the outlet 170 into the chamber 120 to lower the temperature inside the chamber 120, and returns the flowing air to the vicinity of the evaporator 148 through the return air vent 180.

[0037] The low-pressure gaseous refrigerant after evaporation returns to compressor 142, thus repeating the above refrigeration cycle. In some examples, the pressure generated by compressor 142 causes the refrigerant to circulate within refrigerant line 135 along condenser 144, expansion valve 146, and evaporator 148.

[0038] exist Figure 1In this system, the start-up and shutdown of the refrigeration equipment 100 during the stable phase are mainly controlled by the fixed temperature control differential (DIF) inside the refrigeration equipment when the compressor 142 starts and stops. The temperature control differential is the difference between two temperature thresholds that control the compressor's start and stop. For example, if the set temperature (i.e., the target value of the internal temperature of the refrigeration equipment) is 4℃, and the temperature control differential is 2℃, then the compressor will start when the internal temperature of the refrigeration equipment reaches 5℃ and stop when the internal temperature of the refrigeration equipment drops to 3℃ (the shutdown point). The temperature control differential is a direct control parameter that determines the compressor's start-up and shutdown cycle. When the temperature control differential is set too small, it will cause the refrigeration equipment 100 to start and stop frequently, reducing the lifespan of the compressor 142; when the temperature control differential is too large, the compressor 142 will run for too long, easily causing frost to form on the evaporator 148, reducing heat exchanger efficiency, and consequently increasing the energy consumption of the refrigeration equipment 100.

[0039] Figure 2 This is a flowchart of a refrigeration equipment control method provided in this disclosure. Figure 2 As shown, the method includes:

[0040] Step 201: When the refrigeration equipment enters a stable operating state and is not in an energy-saving state, adjust the current temperature control hysteresis to obtain the target temperature control hysteresis.

[0041] Step 202: Adjust the compressor start-up frequency according to the target temperature control hysteresis.

[0042] The method proposed in this embodiment is for fixed-frequency compressor refrigeration systems. Compared to variable-frequency compressors, fixed-frequency compressors have lower hardware costs and are easier to maintain. For fixed-frequency compressors, this embodiment introduces "temperature hysteresis," dynamically adjusting the size of the temperature hysteresis to actively regulate the compressor's operating frequency, locking it within the range of lowest energy consumption. The refrigeration equipment needs to be in a relatively stable operating state; this is a prerequisite for ensuring the reliability and accuracy of subsequent judgments on whether the refrigeration equipment is in an energy-saving state and for adjusting the current temperature hysteresis. If the refrigeration equipment has not entered a stable operating state, it continues to run until it does. After determining that the refrigeration equipment has entered a relatively stable operating state, it is determined whether the refrigeration equipment is in an energy-saving state. If the refrigeration equipment is in an energy-saving state, there is no need to adjust the current temperature hysteresis; if the refrigeration equipment is not in an energy-saving state, the compressor's operating frequency is adjusted by regulating the current temperature hysteresis to meet the "energy-saving" requirements.

[0043] In this disclosure, for a fixed-frequency compressor refrigeration system, when the refrigeration equipment enters a stable operating state and is not in energy-saving mode, the current temperature control hysteresis is adjusted to obtain a target temperature control hysteresis. Finally, the compressor's operating frequency is adjusted according to the target temperature control hysteresis. This method dynamically adjusts the temperature control hysteresis solely through a software algorithm, enabling the compressor to operate at the optimal operating frequency, thus simultaneously achieving energy savings and extending the compressor's lifespan.

[0044] In an optional embodiment, the method further includes:

[0045] Determine whether the current cycle time, current set temperature, and current ambient temperature are stable; if so, determine that the refrigeration equipment has entered a stable operating state; otherwise, determine that the refrigeration equipment has not entered a stable operating state.

[0046] The current cycle time includes the compressor's continuous start-up and shutdown time.

[0047] In this embodiment, the refrigeration equipment (such as a freezer) includes a controller. The controller records the start-up and shutdown times of the compressor for each cycle as a complete time interval. For example, at time T0, the compressor starts and runs for t... o The server will be shut down after a certain duration. c The time interval is t0 + t1, and it restarts at time T1. The duration between T0 and T1 is t0 + t1, which is the time of one complete cycle, T = t. o + t c The current recorded loop time is used as the current loop time.

[0048] The current set temperature is the target value that the internal temperature of the refrigeration equipment is intended to reach.

[0049] The refrigeration equipment also includes an ambient temperature sensor, which measures the current temperature of the external environment in which the refrigeration equipment is located.

[0050] Optionally, the steps to determine whether the current loop time is stable are as follows:

[0051] When the compressor of the refrigeration equipment starts and stops regularly, the time of each cycle is acquired. After obtaining the current cycle time, the controller calculates the ratio of the absolute value of the difference between the current cycle time and the previous cycle time to the previous cycle time: where k represents the number of cycles. If this ratio... If the current cycle time is less than a preset time threshold (e.g., 5%), then the current cycle time is considered stable.

[0052] Optionally, the steps to determine whether the current set temperature is stable are as follows:

[0053] Get the current set temperature SP k Calculate the current set temperature SP k Compared to the previous set temperature SP k-1 The absolute value of the difference: If the absolute value Less than the preset temperature threshold Th sp If the temperature is 2℃, then the current set temperature is considered stable.

[0054] Alternatively, the steps to determine whether the current ambient temperature is stable are as follows:

[0055] Get the current ambient temperature T amb,k Calculate the current ambient temperature T amb,k Compared to the previous ambient temperature T amb,k-1 The absolute value of the difference: If the absolute value Less than the preset ambient temperature threshold Th amb If the temperature is 3℃, then the current ambient temperature is considered stable.

[0056] Once the conditions of stable current cycle time, stable current set temperature, and stable current ambient temperature are met, the refrigeration equipment is considered to be in a relatively stable operating state.

[0057] In an optional embodiment, the method further includes:

[0058] Determine whether the refrigeration equipment is in energy-saving mode based on the compressor's current operating frequency and the target energy-saving frequency.

[0059] The current power-on frequency is calculated based on the current cycle time.

[0060] In this embodiment of the application, the determination of whether the refrigeration equipment is in an energy-saving state is made under the premise that the refrigeration equipment is in a relatively stable operating state.

[0061] Figure 3 This disclosure provides a flowchart for determining whether a refrigeration device is in an energy-saving state. For example... Figure 3 As shown, determining whether the refrigeration equipment is in energy-saving mode based on the compressor's current operating frequency and the target energy-saving frequency includes:

[0062] Step 301: Based on the current ambient temperature and the current set temperature, retrieve the target energy-saving frequency from the pre-stored target energy-saving frequency table;

[0063] Step 302: Determine whether the deviation between the current start-up frequency and the target energy-saving frequency is within the target frequency deviation range; if so, the refrigeration equipment is in energy-saving mode; otherwise, the refrigeration equipment is not in energy-saving mode.

[0064] In this embodiment, the controller calculates the current power-on frequency f based on the current cycle time T. n The unit of frequency is usually "times per hour". The calculation formula is: f n = 3600 / T (where T is in seconds).

[0065] The refrigeration equipment also includes a memory that stores a target energy-saving frequency table, as shown in Table 1. This table stores the target energy-saving frequencies for different operating conditions (i.e., different combinations of ambient temperature and set temperature). The target energy-saving frequency can be obtained by querying the pre-stored table: the controller reads the current value from the ambient temperature sensor to obtain the current ambient temperature T. amb It then reads the user-set current temperature SP. Afterwards, it uses T... amb Using SP as an index, a lookup is performed in the pre-stored target energy-saving frequency table in memory to obtain the frequency relative to the current ambient temperature T. amb The target energy-saving frequency f matches the current set temperature SP. target .

[0066] Among them, the target energy-saving frequency table is the optimal energy efficiency operating point determined for this specific model of refrigeration equipment under different ambient temperatures and set temperatures through a large number of experimental tests and thermodynamic modeling.

[0067] Table 1 Target Energy Saving Frequency Table

[0068]

[0069] Among them, f in Table 1 01 to f 66 This indicates the target energy-saving frequency combination under the corresponding ambient temperature and set temperature. The subscripts 01 to 66 are a sorting of the target energy-saving frequencies combined under different ambient temperatures and set temperatures.

[0070] After obtaining the current power-on frequency and the target energy-saving frequency, the controller calculates the current power-on frequency f. n With the target energy-saving frequency f target The deviation between the target frequency and the set threshold is then determined. If the deviation is within the target frequency deviation range, the refrigeration equipment is determined to be in energy-saving mode and no adjustment is required. The controller returns to the normal temperature control mode and waits for the next stable operating state before re-evaluating. Otherwise, the refrigeration equipment is determined not to be in energy-saving mode and the current temperature control hysteresis needs to be adjusted. In this embodiment, when determining the target frequency deviation range, a tolerance range can be defined, such as ±5% of the target frequency. Through this tolerance range, the deviation range of the target frequency can be determined as [-5%×f]. target 5%×f targetIf -5%×f target ≤f n -f target ≤-5%×f target (i.e., 0.95≤f) n / f target If f ≤ 1.05), the controller considers the refrigeration equipment to be in energy-saving mode; if f n -f target <-5%×f target (i.e. f) n / f target <0.95) or f n -f target >5%×f target (i.e. f) n / f target If the value is greater than 1.05, the controller considers the refrigeration equipment to be in an energy-saving state.

[0071] In an optional embodiment, when the refrigeration equipment enters a stable operating state and is not in an energy-saving state, the current temperature control hysteresis is adjusted to obtain a target temperature control hysteresis, including:

[0072] If the difference between the current power-on frequency and the target energy-saving frequency is greater than the maximum value of the target frequency deviation range, then the current temperature control hysteresis is increased by a specified step size to obtain the target temperature control hysteresis.

[0073] If the difference between the current power-on frequency and the target energy-saving frequency is less than the minimum value of the target frequency deviation range, then the current temperature control hysteresis is reduced by a specified step size to obtain the target temperature control hysteresis.

[0074] Optionally, the current temperature control hysteresis can be increased by a specified step size to obtain the target temperature control hysteresis, as follows:

[0075]

[0076] in, This refers to the current temperature control hysteresis. This is the adjusted target temperature control hysteresis; This is the step size for this adjustment. Step size It can be a fixed value (e.g., 0.1℃), adjusted in small increments each time, and after several cycles, the trend of frequency change is observed. More preferably, the step size... It can be compared with the current power-on frequency f n and target energy-saving frequency f target The magnitude of the deviation is directly proportional to the magnitude of the deviation, that is... ,in It is a proportional coefficient, calibrated according to the specific system. In this way, when the deviation is large, the adjustment step size is larger, resulting in faster convergence; when the deviation is small, the adjustment step size is smaller, resulting in more precise control.

[0077] The target temperature control hysteresis is obtained by decreasing the current temperature control hysteresis by a specified step size, as follows:

[0078]

[0079] Among them, DIF new Adjusted temperature control hysteresis; step size It can be a fixed value (e.g., 0.1℃). More preferably, the step size... It can be used with the target energy-saving frequency f target When the previous power-on frequency f n The magnitude of the deviation is directly proportional to the magnitude of the deviation, that is... .

[0080] In another optional embodiment, when the refrigeration equipment enters a stable operating state and is not in an energy-saving state, the current temperature control hysteresis is adjusted to obtain a target temperature control hysteresis, including:

[0081] Based on the current ambient temperature and the current set temperature, the optimal temperature control hysteresis is obtained by querying the pre-stored target energy-saving frequency table.

[0082] If the current temperature control hysteresis is less than the optimal temperature control hysteresis, then the current temperature control hysteresis is gradually increased through the first linear relationship to obtain the target temperature control hysteresis;

[0083] If the current temperature control hysteresis is greater than the optimal temperature control hysteresis, then the current temperature control hysteresis is gradually reduced through the second linear relationship to obtain the target temperature control hysteresis;

[0084] The first linear relationship determines the increment by using the difference between the current temperature control hysteresis and the optimal temperature control hysteresis, and iteratively increases the current temperature control hysteresis using this increment as the step size. Optionally, the first linear relationship is:

[0085]

[0086] In the formula, DIF represents the current temperature control hysteresis; e To achieve the optimal temperature control hysteresis, where i is the current iteration number and the total number of iterations is set to 4n; DIF new This is the temperature control hysteresis adjusted in the i-th iteration.

[0087] The second linear relationship determines the reduction amount by using the difference between the current temperature control hysteresis and the optimal temperature control hysteresis, and iteratively reduces the current temperature control hysteresis using this reduction amount as the step size. Optionally, the second linear relationship is:

[0088]

[0089] In this embodiment, for each combination of ambient temperature and set temperature shown in Table 1, there is a corresponding optimal temperature control hysteresis DIF. e Optimal temperature control hysteresis DIF e Based on the calculations, the following parameters are now given to facilitate the calculations:

[0090] t1 and t2 are the cooling and warming times within a start-stop cycle, respectively, in minutes; Q is the compressor's cooling capacity per minute, in J; k is the cold leakage per unit temperature of the freezer's insulation layer and door, in W / K; q1 is the power of the compressor and condenser fan, in W; q2 is the power of the evaporator fan, in W; m is the load mass, in kg; c is the load specific heat, in J / [kg•K]; ξ is the average temperature correction coefficient for the freezer load in different temperature control ranges; T0 is the ambient temperature, in K.

[0091] During the recovery phase, the internal load of the refrigeration equipment and heat exchange with the environment cause the internal temperature of the refrigeration equipment to rise (DIF). Then time During the cooling phase, heat is absorbed by the evaporator and released into the environment through the condenser. According to the law of conservation of energy, we can obtain... ,but The average energy consumption during the entire start-up and shutdown phase is... The minimum energy consumption value can be calculated based on the function expression.

[0092] For each combination of ambient temperature and set temperature, a different temperature control hysteresis DIF is given. e -0.5, DIF e and DIF e +0.5. Since the effect of temperature control hysteresis on the set temperature is symmetrical, the internal temperature of the refrigeration equipment does not change much when the temperature control hysteresis changes.

[0093] Figure 4 This disclosure provides a flowchart for adjusting the current temperature control hysteresis. For example... Figure 4 As shown, first, determine if the refrigeration equipment is in energy-saving mode. If so, keep the parameters unchanged and record the current temperature control hysteresis DIF. Otherwise, gradually increase the current temperature control hysteresis DIF using the first linear relationship, or gradually decrease it using the second linear relationship. The method to gradually increase the current temperature control hysteresis using the first linear relationship is as follows: let the current temperature control hysteresis DIF start from... Gradually increase the temperature, and at each increase, determine whether the outlet air temperature is lower than the outlet air temperature threshold T. lowIf so, the compressor stops, and the new temperature control hysteresis is ineffective. Otherwise, it is further determined whether the refrigeration equipment is in energy-saving mode. If the refrigeration equipment is in energy-saving mode, the parameters remain unchanged, and the current temperature control hysteresis DIF is recorded. Otherwise, the difference between the current start-up frequency and the target energy-saving frequency D1 and the difference between the previous start-up frequency and the target energy-saving frequency D2 are calculated. If D1 > D2, the new temperature control hysteresis is ineffective, and it is determined whether the current iteration number i is less than the preset total iteration number 4n. If the current iteration number i is greater than or equal to the total iteration number 4n, the set value remains unchanged. If the current iteration number i is less than the total iteration number 4n, i is set to 1 + 1, and the next iteration begins. Through the above iterations, the energy-saving start-up requirements are met or the current temperature control hysteresis DIF = .

[0094] The method to gradually reduce the current temperature control hysteresis using the second linear relationship is as follows: Let the current temperature control hysteresis DIF decrease from... Gradually decrease the temperature, and at each decrease, determine whether the outlet air temperature is lower than the outlet air temperature threshold T. low If so, the compressor stops, and the new temperature control hysteresis is ineffective. Otherwise, it is further determined whether the refrigeration equipment is in energy-saving mode. If the refrigeration equipment is in energy-saving mode, the parameters remain unchanged, and the current temperature control hysteresis DIF is recorded. Otherwise, the difference between the current operating frequency and the target energy-saving frequency D1 and the difference between the previous operating frequency and the target energy-saving frequency D2 are calculated. If D1 > D2, the new temperature control hysteresis is ineffective, and it is determined whether the current iteration number i is less than the preset total iteration number 4n. If the current iteration number i is greater than or equal to the preset total iteration number 4n, the set value remains unchanged. If the current iteration number i is less than the total iteration number 4n, i is set to 1 + 1, and the next iteration begins. Through the above iterations, the energy-saving operating rate requirement is met or the current temperature control hysteresis DIF = .

[0095] During the iterative calculation of the temperature control hysteresis mentioned above, when the automatic adjustment of the start-up and shutdown points occurs, the internal temperature of the refrigeration equipment may become too low. In this case, a low-temperature protection parameter T is introduced. low A temperature probe S1 is installed near the air outlet. The temperature is then compared with the temperature T. low The size of the temperature reading determines whether to enter the low-temperature protection mode. Once in low-temperature protection mode, the compressor stops, but the evaporator fan continues to run. When the SI feedback temperature is higher than T... low When +3, the system enters normal control mode and stops DIF automatic adjustment. When the set temperature or ambient temperature changes (set temperature change greater than 2℃, ambient temperature change greater than 3℃), the DIF adjustment function is re-entered.

[0096] Figure 5-7The graph shows the internal temperature test results of the refrigeration equipment (such as a freezer) provided in this disclosure at DIF=1.5, DIF=2, and DIF=3. The horizontal axis represents time / min, the left vertical axis represents temperature / ℃, and the right vertical axis represents the total power of the freezer / W. Figure 5-7 As shown in the figure, only the temperature control hysteresis was changed in the experiment, while the other experimental conditions remained unchanged. By setting DIF=1.5, 2, and 3, the cycle start-stop times were calculated to be 25 min, 33 min, and 59 min, respectively. As shown in Table 2, the number of start-ups and shutdowns per hour were obtained as 2.40, 1.82, and 1.02, respectively. The final calculated average energy consumption was 1.302, 1.423, and 1.432 [kW•h / 24h]. According to the test results, energy-saving effects were achieved.

[0097] Table 2 Comparison of energy consumption for different DIFs

[0098]

[0099] Among them, the characteristic temperature is the average temperature inside the freezer, and the average power is the average power of the freezer over multiple start-stop cycles.

[0100] In this embodiment, considering the limited memory of the electronic temperature controller, except for the standard operating conditions in Table 1 which cannot be deleted, the other operating conditions can be forgotten when memory is insufficient.

[0101] In this embodiment, the system first determines whether the refrigeration equipment is in energy-saving mode based on the current start-up frequency. If it is not in energy-saving mode, the system adjusts the current temperature control hysteresis to change the temperature thresholds corresponding to compressor start-up and shutdown, thereby changing the cycle time. The corrected start-up frequency can be calculated from the cycle time, thus realizing a complete closed-loop control chain.

[0102] In an optional embodiment, the method further includes:

[0103] Adjust the evaporator fan speed according to the current temperature control hysteresis.

[0104] Figure 8 This is a flowchart illustrating how to adjust the speed of an evaporator fan, as provided in this disclosure. Figure 8 As shown, the evaporator fan speed is adjusted according to the current temperature control hysteresis, including:

[0105] During the cooling phase:

[0106] The difference T between the internal temperature of the refrigeration equipment and the currently set temperature. d1 If the temperature difference exceeds the maximum value of the first temperature difference range (which can be set to -0.5×DIF~0.5×DIF in this embodiment), the difference T between the internal temperature of the refrigeration equipment and the temperature of the evaporator fan is determined. d2Is the temperature difference greater than or equal to the first temperature difference threshold T1? If so, adjust the evaporator fan speed to the preset maximum speed value F. ea Otherwise, adjust the evaporator fan speed to the preset minimum speed value F. ei ;

[0107] The difference T between the internal temperature of the refrigeration equipment and the currently set temperature. d1 Under the condition of being within the first temperature difference range, determine the difference T between the internal temperature of the refrigeration equipment and the temperature of the evaporator fan. d2 Is it greater than or equal to the second temperature difference threshold T2? If so, adjust the evaporator fan speed to the preset maximum speed value F. ea Otherwise, control the evaporator fan with stepless speed regulation;

[0108] The difference T between the internal temperature of the refrigeration equipment and the currently set temperature. d1 If the temperature difference is less than the minimum value of the first temperature range, adjust the evaporator fan speed to the preset minimum speed value F. ei It also starts and stops on a set schedule;

[0109] During the recovery phase:

[0110] The difference T between the internal temperature of the refrigeration equipment and the currently set temperature. d1 When the temperature difference is within the first range, adjust the evaporator fan speed to the preset minimum speed F. ei It also starts and stops on a set schedule;

[0111] The first temperature difference range is set according to the current temperature control hysteresis.

[0112] In this embodiment, the first temperature difference threshold can be set to 5, and the second temperature difference threshold can be set to 10. Table 1 shows that for each combination of ambient temperature and set temperature, there is a corresponding maximum evaporator fan speed F. ea and minimum speed F ei During the cooling phase, when T... d1 When the value is >0.5×DIF, the compressor starts, and the evaporator fan operates in two modes: T d2 When <5, adjust the evaporator fan speed to F. ei Conversely, adjust the evaporator fan speed to F. ea When -0.5×DIF <T d1 When <0.5×DIF, the evaporator fan also operates in two speeds: T d2 When the speed is less than 10, the evaporator fan speed is continuously adjustable; otherwise, the evaporator fan speed is adjusted to F. ea When T d1 When the value is less than -0.5 × DIF, the compressor stops, and the evaporator fan speed is adjusted to F. ei It is started and stopped at regular intervals. During the warm-up phase, when -0.5×DIF <T d1When the value is less than 0.5 × DIF, the compressor stops, and the evaporator fan speed is adjusted to F. ei Scheduled start / stop. T d2 = T d1 +SP-T ea T ea This refers to the temperature of the evaporator fan.

[0113] The aforementioned strategy of coordinated control between the compressor and the evaporator ensures that the operation of the evaporator matches the compressor at different stages of operation, maximizing the utilization efficiency of cooling capacity.

[0114] This disclosure also provides a refrigeration equipment control system, the system including a controller;

[0115] The controller is configured as follows:

[0116] When the refrigeration equipment enters a stable operating state and is not in energy-saving mode, the current temperature control hysteresis is adjusted to obtain the target temperature control hysteresis;

[0117] Adjust the compressor's start-up frequency according to the target temperature control hysteresis;

[0118] Among them, temperature hysteresis is the difference between two temperature thresholds that control the start and stop of the compressor.

[0119] In this disclosure, for a fixed-frequency compressor refrigeration system, when the refrigeration equipment enters a stable operating state and is not in energy-saving mode, the current temperature control hysteresis is adjusted to obtain a target temperature control hysteresis. Finally, the compressor's operating frequency is adjusted according to the target temperature control hysteresis. This method dynamically adjusts the temperature control hysteresis solely through a software algorithm, enabling the compressor to operate at the optimal operating frequency, thus simultaneously achieving energy savings and extending the compressor's lifespan.

[0120] This disclosure also provides a refrigeration device, which includes the refrigeration device control system described in the above embodiments.

[0121] This disclosure also provides a computer-readable storage medium storing at least one instruction that is executed by a processor to implement the refrigeration device control method as described in the above embodiments.

[0122] This disclosure also provides a computer program product including computer instructions stored in a computer-readable storage medium; a processor of a computing device reads the computer instructions from the computer-readable storage medium and executes the computer instructions, causing the computing device to perform the refrigeration equipment control method described in the above embodiments.

[0123] Those skilled in the art will recognize that the functions described in this disclosure in one or more of the examples above can be implemented using hardware, software, firmware, or any combination thereof. When implemented in software, these functions can be stored in a computer-readable medium or transmitted as one or more instructions or code on a computer-readable medium. Computer-readable media include computer storage media and communication media, wherein communication media include any medium that facilitates the transfer of a computer program from one place to another. Storage media can be any available medium accessible to a general-purpose or special-purpose computer.

[0124] It should be noted that the technical solutions described in this disclosure can be combined arbitrarily as long as they do not conflict.

[0125] The above description is merely a specific embodiment of this disclosure, but the scope of protection of this disclosure is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this disclosure should be included within the scope of protection of this disclosure.

Claims

1. A method for controlling a refrigeration equipment, characterized in that, The method includes: When the refrigeration equipment enters a stable operating state and is not in energy-saving mode, the current temperature control hysteresis is adjusted to obtain the target temperature control hysteresis; Adjust the compressor's start-up frequency according to the target temperature control hysteresis; The temperature hysteresis is the difference between two temperature thresholds that control the compressor to start and stop. When the refrigeration equipment enters a stable operating state and is not in an energy-saving state, adjusting the current temperature control hysteresis to obtain the target temperature control hysteresis includes: Based on the current ambient temperature and the current set temperature, the optimal temperature control hysteresis is obtained by querying the pre-stored target energy-saving frequency table. If the current temperature control hysteresis is less than the optimal temperature control hysteresis, then the current temperature control hysteresis is gradually increased through the first linear relationship to obtain the target temperature control hysteresis; If the current temperature control hysteresis is greater than the optimal temperature control hysteresis, then the current temperature control hysteresis is gradually reduced through the second linear relationship to obtain the target temperature control hysteresis; The first linear relationship determines the increase amount by the difference between the current temperature control hysteresis and the optimal temperature control hysteresis, and gradually increases the current temperature control hysteresis by iteratively using the increase amount as the step size; The second linear relationship determines the reduction amount by the difference between the current temperature control hysteresis and the optimal temperature control hysteresis, and gradually reduces the current temperature control hysteresis by using the reduction amount as the step size through iteration.

2. The refrigeration equipment control method according to claim 1, characterized in that, The method further includes: Determine whether the current cycle time, current set temperature, and current ambient temperature are stable; if so, determine that the refrigeration equipment has entered a stable operating state; otherwise, determine that the refrigeration equipment has not entered a stable operating state. The current cycle time includes the compressor's continuous start-up and shutdown time. The current set temperature is the target value that the internal temperature of the refrigeration equipment is intended to achieve.

3. The refrigeration equipment control method according to claim 2, characterized in that, The method further includes: Determine whether the refrigeration equipment is in an energy-saving state based on the compressor's current operating frequency and the target energy-saving frequency; The current power-on frequency is calculated based on the current cycle time.

4. The refrigeration equipment control method according to claim 3, characterized in that, The step of determining whether the refrigeration equipment is in energy-saving mode based on the compressor's current operating frequency and the target energy-saving frequency includes: Based on the current ambient temperature and the current set temperature, the target energy-saving frequency is obtained by querying the pre-stored target energy-saving frequency table; Determine whether the deviation between the current power-on frequency and the target energy-saving frequency is within the target frequency deviation range; if so, the refrigeration equipment is in energy-saving mode; otherwise, the refrigeration equipment is not in energy-saving mode.

5. A refrigeration equipment control system, characterized in that, The system includes a controller; The controller is configured to: When the refrigeration equipment enters a stable operating state and is not in energy-saving mode, the current temperature control hysteresis is adjusted to obtain the target temperature control hysteresis; Adjust the compressor's start-up frequency according to the target temperature control hysteresis; The temperature hysteresis is the difference between two temperature thresholds that control the compressor to start and stop. When the refrigeration equipment enters a stable operating state and is not in an energy-saving state, adjusting the current temperature control hysteresis to obtain the target temperature control hysteresis includes: Based on the current ambient temperature and the current set temperature, the optimal temperature control hysteresis is obtained by querying the pre-stored target energy-saving frequency table. If the current temperature control hysteresis is less than the optimal temperature control hysteresis, then the current temperature control hysteresis is gradually increased through the first linear relationship to obtain the target temperature control hysteresis; If the current temperature control hysteresis is greater than the optimal temperature control hysteresis, then the current temperature control hysteresis is gradually reduced through the second linear relationship to obtain the target temperature control hysteresis; The first linear relationship determines the increase amount by the difference between the current temperature control hysteresis and the optimal temperature control hysteresis, and gradually increases the current temperature control hysteresis by iteratively using the increase amount as the step size; The second linear relationship determines the reduction amount by the difference between the current temperature control hysteresis and the optimal temperature control hysteresis, and gradually reduces the current temperature control hysteresis by using the reduction amount as the step size through iteration.

6. A refrigeration device, characterized in that, The refrigeration equipment includes the refrigeration equipment control system as described in claim 5.

7. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores at least one instruction, which is executed by a processor to implement the method as described in any one of claims 1-4.

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