Energy-saving operation closed-loop control method and device for refrigeration equipment

Abstract

The invention belongs to the technical field of uranium concentration, and particularly relates to an energy-saving operation closed-loop control method and device for refrigeration equipment. The method comprises the steps that when it is judged that the number of closed towers needs to be switched, refrigerating capacity change data in the switching process is obtained; on the basis of a pre-obtained frequency compensation model, according to the refrigerating capacity change data, the frequency compensation amount of the operation frequency of the closed towers in the closed tower number switching process is determined; the frequency compensation model is obtained through training in advance according to historical refrigerating capacity change data in the historical switching process and the relationship between the refrigerating capacity and the operation frequency of the closed tower; and in the number switching process of the closed towers, the operation frequency of the closed towers is adjusted based on the frequency compensation amount so as to restrain fluctuation of the output water temperature of the closed towers. According to the embodiment of the invention, the frequency compensation amount of the frequency correction of the closed tower in the switching transition process is output according to the change trend of the refrigerating capacity in the switching process, so that the fluctuation of the output water temperature of the closed tower can be inhibited, and the problem of frequent adjustment during switching of the current closed tower is solved.

Description

Technical Field

[0001] The present application belongs to the field of uranium enrichment technology, and specifically relates to a closed-loop control method and device for energy-saving operation of refrigeration equipment. Background Art

[0002] The multi-stage cascade separation and purification equipment in the uranium enrichment process operates 24 hours a day. The equipment is continuously cooled by process chilled water supplied from outside the unit to maintain a constant temperature. As a key component of the auxiliary control system, process cooling water is continuously circulated, removing heat from the equipment and releasing it to the external environment through heat exchange. Currently, due to the climate characteristics of a certain region, closed-tower cooling is suitable for meeting the heat exchange requirements of industrial cooling water in winter. Fully or partially closed-tower cooling can be used. Compared to the water-cooled main unit cooling mode in summer, closed-tower cooling is more energy-efficient, consuming one-third to one-quarter the energy of the water-cooled main unit.

[0003] However, during winter, the cooling load of closed towers remains relatively stable due to the unique characteristics of the uranium enrichment process. Current designs utilize multiple closed towers in series to provide the required cooling load. Because the cooling efficiency of air varies significantly with 24-hour daytime temperature and humidity fluctuations, the existing control system adjusts the tower fan frequency and adds or subtracts towers to achieve a near-constant cooling load under varying outdoor conditions.

[0004] In actual use, tower fan frequency is regulated using closed-loop PID control technology. The tower addition and removal logic uses a logic where tower addition is triggered when the frequency reaches the upper limit and the outlet water temperature of the closed tower main pipe exceeds the upper threshold. Tower removal is triggered when the frequency reaches the lower limit and the outlet water temperature of the closed tower main pipe falls below the lower threshold, achieving dynamic matching of cooling load output. In some scenarios, the actual adjustment process results in significant temperature fluctuations after tower addition and removal, and there are also instances of switching back and forth between tower addition and removal. Summary of the Invention

[0005] The purpose of this application is to provide a closed-loop control method and device for energy-saving operation of refrigeration equipment, so as to solve the problem in the prior art that the temperature fluctuates greatly after adding or removing a tower, and there is the problem of switching back and forth between adding and removing a tower.

[0006] Technical solution to achieve the purpose of this application:

[0007] A first aspect of an embodiment of the present application provides a closed-loop control method for energy-saving operation of a refrigeration device, the method comprising:

[0008] When it is determined that the number of closed towers needs to be switched, the cooling capacity change data during the switching process is obtained;

[0009] Based on a pre-obtained frequency compensation model, and according to the cooling capacity change data, determining a frequency compensation amount for the operating frequency of the closed tower during the switching process of the number of closed towers; the frequency compensation model is pre-trained based on historical cooling capacity change data during historical switching processes and the relationship between the cooling capacity and operating frequency of the closed towers;

[0010] During the switching process of the number of closed towers, the operating frequency of the closed tower is adjusted based on the frequency compensation amount to suppress fluctuations in the output water temperature of the closed tower.

[0011] Optionally, during the switching process of the number of closed towers, adjusting the operating frequency of the closed tower based on the frequency compensation amount specifically includes:

[0012] During the switching process of the number of closed towers, adding the frequency compensation amount to the current operating frequency of the closed tower;

[0013] During the switching process of the number of closed towers, the operating frequency of the closed tower is adjusted based on the frequency compensation amount, and then further includes:

[0014] After the number of closed towers is switched, the operating frequency of the closed towers is adjusted to the target operating frequency after the switch.

[0015] Optionally, the target operating frequency is obtained according to the following steps:

[0016] Get the current outdoor temperature and required cooling capacity;

[0017] Based on a pre-obtained switching prediction model, the current outdoor temperature and the required cooling capacity are used as input to obtain the corresponding number and frequency of operation of the closed tower; the switching prediction model is trained based on the outdoor temperature, the number and frequency of operation of the closed tower and the corresponding cooling capacity in different periods;

[0018] The target operating frequency is obtained according to the correspondence between the operating quantity and the operating frequency of the closed tower and the target quantity of the closed tower after switching.

[0019] Optionally, the method further includes: determining whether a closed tower quantity switching operation is required by the following steps:

[0020] Obtaining the current outdoor temperature and the target return water temperature of the closed tower;

[0021] Based on a pre-obtained frequency prediction module, the current outdoor temperature and the target return water temperature are used as inputs to predict the operating frequency of the closed tower to obtain a predicted operating frequency;

[0022] According to the predicted operating frequency, it is determined whether a closed tower quantity switching operation is required.

[0023] Optionally, judging whether to perform a closed tower quantity switching operation based on the predicted operating frequency specifically includes:

[0024] When the predicted operating frequency exceeds a preset maximum operating frequency threshold, determining that an operation of increasing the number of closed-loop tower operations is required;

[0025] When the predicted operating frequency is less than a preset minimum operating frequency threshold, it is determined that an operation of reducing the number of closed-loop tower operations is required.

[0026] Optionally, the current outdoor temperature is obtained according to the outdoor wet-bulb temperature of the closed tower.

[0027] Optionally, obtaining the cooling capacity change data during the switching process specifically includes:

[0028] The cooling capacity change data is obtained according to the changed quantity of the closed tower after switching and the current operating frequency of the closed tower.

[0029] A second aspect of an embodiment of the present application provides an energy-saving closed-loop control device for refrigeration equipment, the device comprising:

[0030] The first acquisition module is used to obtain the cooling capacity change data during the switching process when it is determined that the number of closed towers needs to be switched;

[0031] a first determination module, configured to determine, based on a pre-obtained frequency compensation model and the cooling capacity change data, a frequency compensation amount for the operating frequency of the closed tower during the switching process of the number of closed towers; the frequency compensation model being pre-trained based on historical cooling capacity change data during historical switching processes and the relationship between the cooling capacity and operating frequency of the closed towers;

[0032] The frequency compensation module is used to adjust the operating frequency of the closed tower based on the frequency compensation amount during the switching process of the number of closed towers to suppress the fluctuation of the output water temperature of the closed tower.

[0033] A third aspect of an embodiment of the present application provides a computer-readable storage medium having a computer program stored thereon. When the computer program is executed, any one of the energy-saving closed-loop control methods for refrigeration equipment provided in the first aspect of the embodiment of the present application is implemented.

[0034] A fourth aspect of an embodiment of the present application provides an electronic device, including a memory and a processor, wherein a computer program is stored in the memory. When the computer program is executed by the processor, any one of the energy-saving operation closed-loop control methods for refrigeration equipment provided in the first aspect of the embodiment of the present application is implemented.

[0035] The beneficial technical effects of this application are:

[0036] The embodiment of the present application provides a closed-loop control method and device for energy-saving operation of refrigeration equipment, the method comprising: when it is determined that a closed tower number switching operation is required, obtaining cooling capacity change data during the switching process; based on a pre-obtained frequency compensation model, determining the frequency compensation amount for the closed tower operating frequency during the closed tower number switching process according to the cooling capacity change data; the frequency compensation model is pre-trained based on historical cooling capacity change data during the historical switching process, the cooling capacity of the closed tower, and the relationship between the operating frequency; during the closed tower number switching process, adjusting the operating frequency of the closed tower based on the frequency compensation amount to suppress the fluctuation of the closed tower output water temperature. The embodiment of the present application outputs the frequency compensation amount for the closed tower frequency correction during the switching transition process based on the cooling capacity change trend during the switching process, which can improve the original strategy of keeping the frequency unchanged during the transition process, suppress the fluctuation of the closed tower output water temperature, improve the smoothness of the closed tower water temperature output, and solve the problems of large water temperature fluctuations, frequent adjustments, and switching back and forth that are prone to occur during the current closed tower switching. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 A flow chart of a closed-loop control method for energy-saving operation of refrigeration equipment provided in an embodiment of the present application. DETAILED DESCRIPTION

[0038] In order to enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the embodiments described below are only part of the embodiments of the present application, not all of them. Based on the embodiments recorded in this application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of this application.

[0039] See also Figure 1 , which is a flow chart of a closed-loop control method for energy-saving operation of refrigeration equipment provided in an embodiment of the present application.

[0040] An embodiment of the present application provides a closed-loop control method for energy-saving operation of a refrigeration device, comprising:

[0041] Step S101: when it is determined that a closed tower quantity switching operation is required, the cooling capacity change data during the switching process is obtained.

[0042] In some possible implementations of the embodiments of the present application, obtaining the cooling capacity change data during the switching process may specifically include:

[0043] The cooling capacity change data is obtained according to the changed quantity of the closed tower after switching and the current operating frequency of the closed tower.

[0044] Step S102: Based on a pre-obtained frequency compensation model and according to the refrigeration capacity change data, a frequency compensation amount for the operating frequency of the closed tower during the switching of the number of closed towers is determined.

[0045] In this embodiment of the present application, the frequency compensation model can be pre-trained based on historical cooling capacity change data during historical switching processes and the relationship between the cooling capacity and operating frequency of the closed-circuit towers. The closed-circuit tower operating frequency required to compensate for the corresponding cooling capacity change is determined, thereby obtaining a frequency compensation amount for the closed-circuit tower operating frequency during the switching process.

[0046] Step S103: During the switching process of the number of closed towers, the operating frequency of the closed tower is adjusted based on the frequency compensation amount to suppress fluctuations in the output water temperature of the closed tower.

[0047] At present, when switching the number of closed towers, the operating frequency of the closed towers is generally kept unchanged during the switching process for a period of time (such as 2-3 minutes). During the switching process, due to the instability of the return water temperature of the overall closed tower, the cooling capacity changes, affecting the switching effect. Therefore, in the embodiment of the present application, the operating frequency of the closed tower when the number of closed towers is switched is compensated according to the cooling capacity change data during the switching process. This can maintain the stability of the cooling capacity during the switching process, reduce water temperature fluctuations, improve the control accuracy of the water supply temperature, and reduce the energy waste and equipment fatigue loss caused by frequent switching under unnecessary fluctuations.

[0048] Regarding the strategy of setting the starting frequency before and after the addition and subtraction towers, which currently relies on empirical formulas to convert the addition and subtraction towers during switching, by analyzing historical data and establishing the frequency output under different wet-bulb temperatures, the frequency output before and after the addition and subtraction towers can be changed to achieve dynamic setting of the initial frequency after switching under different switching scenarios to reduce fluctuations before and after switching. In specific implementation, the data from the flow meter (such as cooling calculation) can be used to establish a cooling capacity change curve for the start and stop of the closed tower during the transition process, thereby analyzing the cooling capacity change fluctuations during the transition process. Correspondingly, on the basis of the steady-state closed tower fan frequency, a cooling capacity compensation correction term is added to suppress the fluctuation of the closed tower output water temperature.

[0049] In some possible implementations of the embodiment of the present application, step S103 may specifically include:

[0050] During the switching process of the number of closed towers, adding the frequency compensation amount to the current operating frequency of the closed tower;

[0051] After step S103, the following steps may also be included:

[0052] After the number of closed towers is switched, the operating frequency of the closed towers is adjusted to the target operating frequency after the switch.

[0053] In some possible implementations of the embodiments of the present application, the target operating frequency can be obtained according to the following steps:

[0054] Get the current outdoor temperature and required cooling capacity;

[0055] Based on a pre-obtained switching prediction model, the current outdoor temperature and the required cooling capacity are used as input to obtain the corresponding operation number and operation frequency of the closed tower;

[0056] The target operating frequency is obtained according to the correspondence between the operating quantity and the operating frequency of the closed tower and the target quantity of the closed tower after switching.

[0057] In this embodiment of the present application, the switching prediction model is trained based on the outdoor temperature, the number and frequency of closed-loop tower operations, and the corresponding cooling capacity at different times. This model can determine the required operating frequencies for different numbers of closed-loop towers, given the current outdoor temperature and cooling capacity requirements. This embodiment of the present application controls the required operating frequencies for different numbers of closed-loop towers based on the measured temperature changes at that time. This allows for the determination of preset initial frequencies for different tower switching scenarios, predicting the impact of future weather changes on water outlet temperature, and improving control accuracy.

[0058] As an example, the current outdoor temperature can be obtained according to the outdoor wet-bulb temperature of the closed tower.

[0059] In some possible implementations of the embodiments of the present application, the method may further include: determining whether a closed tower quantity switching operation is required by performing the following steps:

[0060] Obtaining the current outdoor temperature and the target return water temperature of the closed tower;

[0061] Based on a pre-obtained frequency prediction module, the current outdoor temperature and the target return water temperature are used as inputs to predict the operating frequency of the closed tower to obtain a predicted operating frequency;

[0062] According to the predicted operating frequency, it is determined whether a closed tower quantity switching operation is required.

[0063] It is understandable that, compared with traditional PID control, this application is based on the current outdoor temperature changes measured at the time for control, and adopts model predictive control. It can predict the output trend under different output changes in the future based on the model, so as to find the optimal path from multiple feasible paths in the future through optimization problems and issue execution commands. Therefore, based on the length of the prediction time and the short-term data predicted in advance, the future outlet water temperature can be predicted to be affected by weather changes, so as to output closed tower control instructions. Such a strategy is forward-looking and can also support the weight design of the optimization problem to reduce the closed tower control action, avoid frequent adjustments, and save energy by limiting the water temperature.

[0064] In one example, determining whether to perform a closed tower quantity switching operation based on the predicted operating frequency may specifically include:

[0065] When the predicted operating frequency exceeds a preset maximum operating frequency threshold, determining that an operation of increasing the number of closed-loop tower operations is required;

[0066] When the predicted operating frequency is less than a preset minimum operating frequency threshold, it is determined that an operation of reducing the number of closed-loop tower operations is required.

[0067] An embodiment of the present application provides a closed-loop control method for energy-saving operation of refrigeration equipment. The method outputs a frequency compensation amount for closed-tower frequency correction in the switching transition process through the cooling capacity change trend in the switching process. This can improve the original measurement strategy of keeping the frequency unchanged in the transition process, suppress the fluctuation of the closed-tower output water temperature, improve the stability of the closed-tower water temperature output, and solve the problems of large water temperature fluctuations, frequent adjustments, and switching back and forth that are prone to occur during the current closed-tower switching.

[0068] Based on the energy-saving closed-loop control method for refrigeration equipment provided in the above embodiment, an embodiment of the present application also provides an energy-saving closed-loop control device for refrigeration equipment.

[0069] An embodiment of the present application provides an energy-saving closed-loop control device for refrigeration equipment, comprising:

[0070] The first acquisition module is used to obtain the cooling capacity change data during the switching process when it is determined that the number of closed towers needs to be switched;

[0071] a first determination module, configured to determine, based on a pre-obtained frequency compensation model and the cooling capacity change data, a frequency compensation amount for the operating frequency of the closed tower during the switching process of the number of closed towers; the frequency compensation model being pre-trained based on historical cooling capacity change data during historical switching processes and the relationship between the cooling capacity and operating frequency of the closed towers;

[0072] The frequency compensation module is used to adjust the operating frequency of the closed tower based on the frequency compensation amount during the switching process of the number of closed towers to suppress the fluctuation of the output water temperature of the closed tower.

[0073] In some possible implementations of the embodiments of the present application, the frequency compensation module may be specifically used to:

[0074] During the switching process of the number of closed towers, adding the frequency compensation amount to the current operating frequency of the closed tower;

[0075] The device may further include:

[0076] The frequency switching module is used to adjust the operating frequency of the closed tower to the target operating frequency after the switching of the number of closed towers is completed.

[0077] In some possible implementations of the embodiments of the present application, the apparatus may further include:

[0078] The second acquisition module is used to obtain the current outdoor temperature and required cooling capacity;

[0079] a second determination module, configured to obtain a corresponding number of operations and operating frequency of the closed towers based on a pre-obtained switching prediction model, taking the current outdoor temperature and the required cooling capacity as input; the switching prediction model is trained based on the outdoor temperature, the number and frequency of operations of the closed towers, and the corresponding cooling capacities at different times;

[0080] The third determining module is configured to obtain the target operating frequency according to the correspondence between the operating quantity and the operating frequency of the closed tower and the target quantity of the closed tower after switching.

[0081] In some possible implementations of the embodiments of the present application, the apparatus may further include:

[0082] A third acquisition module is used to obtain the current outdoor temperature and the target return water temperature of the closed tower;

[0083] a fourth determination module, configured to predict the operating frequency of the closed tower based on the pre-obtained frequency prediction module and taking the current outdoor temperature and the target return water temperature as inputs to obtain a predicted operating frequency;

[0084] The switching judgment module is used to judge whether it is necessary to perform a closed tower quantity switching operation based on the predicted operating frequency.

[0085] In some possible implementations of the embodiments of the present application, the handover determination module may be specifically configured to:

[0086] When the predicted operating frequency exceeds a preset maximum operating frequency threshold, determining that an operation of increasing the number of closed-loop tower operations is required;

[0087] When the predicted operating frequency is less than a preset minimum operating frequency threshold, it is determined that an operation of reducing the number of closed-loop tower operations is required.

[0088] In one example, the current outdoor temperature is obtained according to the outdoor wet-bulb temperature of the closed tower.

[0089] In some possible implementations of the embodiments of the present application, the first acquisition module may be specifically configured to:

[0090] The cooling capacity change data is obtained according to the changed quantity of the closed tower after switching and the current operating frequency of the closed tower.

[0091] An embodiment of the present application provides an energy-saving closed-loop control device for refrigeration equipment. The device outputs a frequency compensation amount for the closed tower frequency correction in the switching transition process through the cooling capacity change trend in the switching process. This can improve the original measurement strategy of keeping the frequency unchanged in the transition process, suppress the fluctuation of the closed tower output water temperature, improve the stability of the closed tower water temperature output, and solve the problems of large water temperature fluctuations, frequent adjustments, and switching back and forth that are prone to occur during the current closed tower switching.

[0092] Based on the energy-saving closed-loop control method and device for refrigeration equipment provided in the above embodiments, the embodiments of the present application also provide a computer-readable storage medium on which a computer program is stored. When the computer program is executed, any one of the energy-saving closed-loop control methods for refrigeration equipment provided in the above embodiments is implemented.

[0093] Based on the energy-saving closed-loop control method and device for refrigeration equipment provided in the above embodiments, an embodiment of the present application also provides an electronic device, including a memory and a processor, wherein a computer program is stored in the memory. When the computer program is executed by the processor, any one of the energy-saving closed-loop control methods for refrigeration equipment provided in the above embodiments is implemented.

[0094] The present application has been described in detail above with reference to the accompanying drawings and embodiments. However, the present application is not limited to the above embodiments. Various modifications can be made within the scope of knowledge possessed by a person skilled in the art without departing from the purpose of the present application. Any content not described in detail in the present application may be based on existing technologies.

Claims

1. A closed-loop control method for energy-saving operation of refrigeration equipment, characterized in that: The method comprises: When it is determined that the number of closed towers needs to be switched, the cooling capacity change data during the switching process is obtained; Based on a pre-obtained frequency compensation model, and according to the cooling capacity change data, determining a frequency compensation amount for the operating frequency of the closed tower during the switching process of the number of closed towers; the frequency compensation model is pre-trained based on historical cooling capacity change data during historical switching processes and the relationship between the cooling capacity and operating frequency of the closed towers; During the switching process of the number of closed towers, the operating frequency of the closed tower is adjusted based on the frequency compensation amount to suppress fluctuations in the output water temperature of the closed tower.

2. The energy-saving closed-loop control method for refrigeration equipment according to claim 1, characterized in that: During the switching process of the number of closed towers, adjusting the operating frequency of the closed tower based on the frequency compensation amount specifically includes: During the switching process of the number of closed towers, adding the frequency compensation amount to the current operating frequency of the closed tower; During the switching process of the number of closed towers, the operating frequency of the closed tower is adjusted based on the frequency compensation amount, and then further includes: After the number of closed towers is switched, the operating frequency of the closed towers is adjusted to the target operating frequency after the switch.

3. The energy-saving closed-loop control method for refrigeration equipment according to claim 2, characterized in that: The target operating frequency is obtained according to the following steps: Get the current outdoor temperature and required cooling capacity; Based on a pre-obtained switching prediction model, the current outdoor temperature and the required cooling capacity are used as input to obtain the corresponding number and frequency of operation of the closed tower; the switching prediction model is trained based on the outdoor temperature, the number and frequency of operation of the closed tower and the corresponding cooling capacity in different periods; The target operating frequency is obtained according to the correspondence between the operating quantity and the operating frequency of the closed tower and the target quantity of the closed tower after switching.

4. The energy-saving closed-loop control method for refrigeration equipment according to claim 1, characterized in that: The method further includes: determining whether a closed tower quantity switching operation is required by the following steps: Obtaining the current outdoor temperature and the target return water temperature of the closed tower; Based on a pre-obtained frequency prediction module, the current outdoor temperature and the target return water temperature are used as inputs to predict the operating frequency of the closed tower to obtain a predicted operating frequency; According to the predicted operating frequency, it is determined whether a closed tower quantity switching operation is required.

5. The energy-saving closed-loop control method for refrigeration equipment according to claim 4, characterized in that: The determining, based on the predicted operating frequency, whether a closed tower quantity switching operation is required specifically includes: When the predicted operating frequency exceeds a preset maximum operating frequency threshold, determining that an operation of increasing the number of closed-loop tower operations is required; When the predicted operating frequency is less than a preset minimum operating frequency threshold, it is determined that an operation of reducing the number of closed-loop tower operations is required.

6. The energy-saving closed-loop control method for refrigeration equipment according to claim 3 or 4, characterized in that: The current outdoor temperature is obtained according to the outdoor wet-bulb temperature of the closed tower.

7. The energy-saving closed-loop control method for refrigeration equipment according to claim 1, characterized in that: The obtaining of cooling capacity change data during the switching process specifically includes: The cooling capacity change data is obtained according to the changed quantity of the closed tower after switching and the current operating frequency of the closed tower.

8. A closed-loop control device for energy-saving operation of refrigeration equipment, characterized in that: The device comprises: The first acquisition module is used to obtain the cooling capacity change data during the switching process when it is determined that the number of closed towers needs to be switched; a first determination module, configured to determine, based on a pre-obtained frequency compensation model and the cooling capacity change data, a frequency compensation amount for the operating frequency of the closed tower during the switching process of the number of closed towers; the frequency compensation model being pre-trained based on historical cooling capacity change data during historical switching processes and the relationship between the cooling capacity and operating frequency of the closed towers; The frequency compensation module is used to adjust the operating frequency of the closed tower based on the frequency compensation amount during the switching process of the number of closed towers to suppress the fluctuation of the output water temperature of the closed tower.

9. A computer-readable storage medium, characterized in that A computer program is stored thereon, and when the computer program is executed, the energy-saving closed-loop control method for refrigeration equipment according to any one of claims 1 to 7 is implemented.

10. An electronic device, characterized in that: The method comprises a memory and a processor, wherein a computer program is stored in the memory, and when the computer program is executed by the processor, the energy-saving closed-loop control method for refrigeration equipment according to any one of claims 1 to 7 is implemented.

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