Balanced control method of modular refrigerating unit and modular refrigerating unit

Abstract

The invention discloses a balance control method of a modular refrigerating unit, which comprises the following steps: step 200, step 210, step 211, obtaining the module liquid supply temperature Ti of each refrigerating module working at present, judging the size of Ti and Tn, if the Ti of the refrigerating module is greater than Tn, raising the frequency of a variable-frequency compressor, and if the Ti of the variable-frequency compressor is greater than Tn, raising the frequency of the variable-frequency compressor; the step 212 comprises the steps that the step 211 is executed repeatedly till Ti of each refrigeration module is smaller than Tn, and then the step 300 is executed; 300, the average value Pv of the working frequencies of the variable frequency compressors of all the refrigeration modules is calculated, then the working frequencies of all the variable frequency compressors are adjusted to the average value Pv, and if the module liquid supply temperature Ti of all the refrigeration modules is smaller than the liquid supply set temperature Tn of all the refrigeration modules, the refrigeration modules are started; if the module liquid supply temperature Ti of the refrigeration module is larger than the set liquid supply temperature Tn, the inverter compressor of each refrigeration module working currently works at the current working frequency, and if the module liquid supply temperature Ti of the refrigeration module is larger than the set liquid supply temperature Tn, the working frequency of the inverter compressor of the refrigeration module is increased, and then the step 200 is executed.

Description

Technical Field

[0001] The present invention relates to the technical field of refrigeration equipment, and in particular to a balanced control method of a modular refrigeration unit and a modular refrigeration unit. Background Art

[0002] Modular refrigeration units are usually composed of multiple refrigeration modules, and are mainly used in large public buildings and large equipment occasions. In actual use, when the modular refrigeration unit is turned on, the opening time of multiple refrigeration modules is different, and usually the fastest opening time will be opened at intervals of a few seconds (such as controlling multiple refrigeration modules to be turned on at the same time will cause a large starting current, that is, a large impact on the power grid), resulting in the actual operating frequency of the compressors of each refrigeration module being inconsistent and may be quite different; and due to differences in unit components (compressors and other components) and other factors, the actual operating frequency of the compressors of each refrigeration module will also be inconsistent; therefore, the actual operating status of each refrigeration module is different, resulting in a relatively large energy consumption of the unit system. Summary of the invention

[0003] The object of the present invention is to provide a control method for a modular refrigeration unit which is helpful for energy-saving and coordinated operation of the modular refrigeration unit and enables the modular refrigeration unit to operate in a balanced manner.

[0004] A first aspect of the present invention discloses a balanced control method for a modular refrigeration unit, wherein the modular refrigeration unit comprises a fluid pipeline, a refrigeration fluid in the fluid pipeline, a main heat exchanger for passing the refrigeration fluid to cool a heat load, and a plurality of refrigeration modules, wherein the refrigeration module comprises a variable frequency compressor, a condenser, an expansion valve, and a module heat exchanger for cooling the refrigeration fluid connected in sequence, wherein the fluid pipeline connects the module heat exchanger and the main heat exchanger of the refrigeration module so that the refrigeration fluid flows between the module heat exchanger and the main heat exchanger, and the balanced control method for the modular refrigeration unit comprises:

[0005] Step 100, start each refrigeration module, and then execute step 200;

[0006] Step 200 includes step 210, and step 210 includes step 211 and step 212. Step 211 includes: obtaining the module liquid supply temperature Ti of the refrigeration fluid output by the module heat exchanger of each refrigeration module currently in operation and its variable frequency compressor at the current operating frequency, judging the size of the module liquid supply temperature Ti of each refrigeration module and its liquid supply setting temperature Tn, and if the module liquid supply temperature Ti of a refrigeration module is greater than its liquid supply setting temperature Tn, then increasing the operating frequency of the variable frequency compressor of the refrigeration module, and step 212 includes: repeatedly executing step 211 until the module liquid supply temperature Ti of each refrigeration module is less than its liquid supply setting temperature Tn, and then executing step 300;

[0007] Step 300 includes: calculating the average value Pv of the operating frequency of the variable frequency compressor of each refrigeration module, and then adjusting the operating frequency of the variable frequency compressor of each refrigeration module to the average value Pv. If the module liquid supply temperature Ti of each refrigeration module whose operating frequency is the average value Pv is lower than its liquid supply set temperature Tn, the variable frequency compressor of each refrigeration module currently operating operates at the current operating frequency. If the module liquid supply temperature Ti of a refrigeration module is higher than its liquid supply set temperature Tn, the operating frequency of the variable frequency compressor of the refrigeration module is increased, and then step 200 is executed.

[0008] In some embodiments, step 100 further includes: increasing the operating frequency of the variable frequency compressor of each refrigeration module to an initial stable operating frequency, and then executing step 200.

[0009] In some embodiments, step 100 also includes: obtaining the temperature difference Tk between the inlet refrigeration fluid and the outlet refrigeration fluid of the total heat exchanger when the variable frequency compressor of each refrigeration module is at the initial working stable frequency, and judging whether the temperature difference Tk is greater than the first set temperature N1; if it is judged that the temperature difference Tk is greater than the first set temperature N1, executing step 200.

[0010] In some embodiments, step 100 also includes: obtaining the temperature difference Tk between the inlet refrigeration fluid and the outlet refrigeration fluid of the total heat exchanger when the variable frequency compressor of each refrigeration module is at the initial working stable frequency, and judging whether the temperature difference Tk is greater than the first set temperature N1; if the temperature difference Tk is judged to be less than the first set temperature N1, executing step 210, and then judging whether the temperature difference Tk is greater than the first set temperature N1; if the temperature difference Tk is judged to be greater than the first set temperature N1, executing step 200.

[0011] In some embodiments, step 100 also includes: obtaining the temperature difference Tk between the inlet refrigeration fluid and the outlet refrigeration fluid of the total heat exchanger when the variable frequency compressor of each refrigeration module is at the initial working stable frequency, and judging whether the temperature difference Tk is greater than the first set temperature N1; if the temperature difference Tk is judged to be less than the first set temperature N1, executing step 210, and then judging whether the temperature difference Tk is greater than the first set temperature N1; if the temperature difference Tk is judged to be less than the first set temperature N1, judging whether Tk is less than the second set temperature N2; if the temperature difference Tk is judged to be greater than the second set temperature N2, shutting down at least one refrigeration module, and then executing step 200; if the temperature difference Tk is judged to be less than the second set temperature N2, shutting down the modular refrigeration unit.

[0012] In some embodiments, the balancing control method of the modular refrigeration unit also includes step 400 performed after step 300, and step 400 includes: obtaining the main supply liquid temperature Tm of the refrigeration fluid at the inlet of the total heat exchanger, judging the size of the main supply liquid temperature Tm and the main supply liquid demand temperature Tg, and if it is judged that Tm is greater than Tg, shutting down the modular refrigeration unit.

[0013] A second aspect of the present invention discloses a modular refrigeration unit, which uses any of the above-described balanced control methods for modular refrigeration units. The modular refrigeration unit includes: a fluid pipeline, a refrigeration fluid located in the fluid pipeline, a main heat exchanger for passing the refrigeration fluid to cool the heat load, and multiple refrigeration modules. The refrigeration module includes a variable frequency compressor, a condenser, an expansion valve and a module heat exchanger for cooling the refrigeration fluid connected in sequence. The fluid pipeline connects the module heat exchanger and the main heat exchanger of the refrigeration module so that the refrigeration fluid flows between the module heat exchanger and the main heat exchanger. The refrigeration module also includes a temperature detection sensor for detecting the temperature of the refrigeration fluid output by the module heat exchanger.

[0014] In some embodiments, the modular refrigeration unit further comprises a first temperature sensor for detecting the temperature of the refrigeration fluid at the inlet of the main heat exchanger and a second temperature sensor for detecting the temperature of the refrigeration fluid at the outlet thereof.

[0015] In some embodiments, the refrigeration module includes a module controller connected to the variable frequency compressor and the temperature detection sensor signal, the modular refrigeration unit includes a main controller connected to the module controller signal, the module controller is configured to adjust the operating frequency of the variable frequency compressor according to the detection result of the temperature detection sensor, and the main controller is configured to calculate the average operating frequency of the variable frequency compressor of each refrigeration module and send a signal to the module controller to adjust the frequency of the corresponding variable frequency compressor.

[0016] In some embodiments, the modular refrigeration unit also includes a manual operation control panel connected to the main controller signal, and the manual operation control panel is configured to be used for manual operation and to transmit control signals to the module controller through the main controller to control the startup and shutdown of the modular refrigeration unit or set the liquid supply set temperature of the refrigeration module.

[0017] Based on the balanced control method of the modular refrigeration unit provided by the present invention, the variable frequency compressors of each refrigeration module can be made to operate at the same and lower operating frequency. Under this operating frequency, each refrigeration module can ensure that the refrigeration effect on the refrigeration fluid meets the requirements. The modular refrigeration unit has low energy consumption and low noise and is in a stable and balanced good working state.

[0018] Further features and advantages of the present invention will become apparent from the following detailed description of exemplary embodiments of the present invention with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of this application. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0020] Figure 1 A flow chart of a balanced control method for a modular refrigeration unit according to an embodiment of the present invention;

[0021] Figure 2 A schematic diagram of the structure of a modular refrigeration unit according to an embodiment of the present invention;

[0022] Figure 3 for Figure 2 The enlarged structural schematic diagram of the refrigeration module of the modular refrigeration unit is shown. DETAILED DESCRIPTION

[0023] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is by no means intended to limit the present invention and its application or use. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0024] Unless otherwise specifically stated, the relative arrangement, numerical expressions and numerical values ​​of the parts and steps set forth in these embodiments do not limit the scope of the present invention. Meanwhile, it should be understood that, for ease of description, the sizes of the various parts shown in the accompanying drawings are not drawn according to the actual proportional relationship. The technology, method and equipment known to those of ordinary skill in the relevant art may not be discussed in detail, but in appropriate cases, the technology, method and equipment should be considered as a part of the specification. In all examples shown and discussed here, any specific value should be interpreted as being merely exemplary, rather than as a limitation. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters represent similar items in the following drawings, and therefore, once a certain item is defined in an accompanying drawing, it does not need to be further discussed in subsequent drawings.

[0025] In the description of the present invention, it should be understood that the use of terms such as "first" and "second" to limit components is only for the convenience of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore cannot be understood as limiting the scope of protection of the present invention.

[0026] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be directly connected or indirectly connected through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0027] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used here to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" may include both "above" and "below". The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0028] like Figure 2 and Figure 3 As shown, the modular refrigeration unit of this embodiment includes a fluid pipeline, a refrigeration fluid in the fluid pipeline, a total heat exchanger 23 for passing the refrigeration fluid to cool the heat load, and a plurality of refrigeration modules 1. Figure 2In the embodiment shown, as shown in the dotted box, 5 refrigeration modules are included. The refrigeration module 1 includes a variable frequency compressor 11, a condenser 12, an expansion valve 13 and a module heat exchanger 14 for cooling the refrigeration fluid, which are connected in sequence. The fluid pipeline connects the module heat exchanger 14 of the refrigeration module 1 and the main heat exchanger 23 so that the refrigeration fluid flows between the module heat exchanger 14 and the main heat exchanger 23. The refrigerant in the refrigeration module 1 is compressed in the variable frequency compressor 11, then enters the condenser 12 to dissipate heat, and then enters the module heat exchanger to cool the refrigeration fluid entering the module heat exchanger after adiabatic expansion through the expansion valve, and then the refrigerant enters the compressor 11 again. In the embodiment shown in the figure, the refrigeration module also includes a gas-liquid separation device 16, and the refrigerant enters the variable frequency compressor 11 after passing through the gas-liquid separation device 16. The refrigeration fluid circulates in the fluid pipeline, and after entering the module heat exchanger of each refrigeration module, it is cooled by the module heat exchanger of each refrigeration module, then flows out of the module heat exchanger, and then enters the main heat exchanger to cool the heat load that needs to be cooled.

[0029] The balanced control method of the modular refrigeration unit of this embodiment includes step 100, step 200 and step 300.

[0030] Step 100, start each refrigeration module 1, and then execute step 200. Turn on each refrigeration module to cool the refrigeration fluid.

[0031] Step 200 includes step 210, and step 210 includes step 211 and step 212. Step 211 includes: obtaining the module liquid supply temperature Ti of the refrigeration fluid output by the module heat exchanger 14 of each refrigeration module 1 currently in operation when its variable frequency compressor 11 is at the current operating frequency, judging the size of the module liquid supply temperature Ti of each refrigeration module 1 and its liquid supply setting temperature Tn, and if the module liquid supply temperature Ti of a refrigeration module 1 is greater than its liquid supply setting temperature Tn, then increasing the operating frequency of the variable frequency compressor 11 of the refrigeration module 1. Step 212 includes: repeatedly executing step 211 until the module liquid supply temperature Ti of each refrigeration module 1 is less than its liquid supply setting temperature Tn, and then executing step 300.

[0032] In order to ensure that the refrigerant fluid entering the total heat exchanger has sufficient cooling capacity for the heat load, a supply liquid set temperature Tn is set for each refrigeration module, which means that the refrigerant fluid passing through the module heat exchanger of the refrigeration module 1 needs to be cooled to a temperature below the supply liquid set temperature Tn for output by the refrigeration module 1. Each refrigeration module has its own corresponding Tn, and the supply liquid set temperature Tn of each refrigeration module can be set to be the same or different. The specific value of Tn can be set according to the heat load to be cooled by the modular refrigeration unit.

[0033] Obtain the module liquid supply temperature Ti of the refrigerant fluid output by the module heat exchanger 14 of each currently operating refrigeration module 1 when its variable frequency compressor 11 is at the current operating frequency, that is, find the refrigeration module 1 that is cooling the refrigerant fluid, and then obtain the module liquid supply temperature Ti when its variable frequency compressor is working at the current operating frequency. In order to obtain the module liquid supply temperature Ti, preferably, after the frequency of the variable frequency compressor reaches the current operating frequency for the first time, the module liquid supply temperature Ti is measured again after a certain time t1, for example, 30s. Within a certain range, the longer the t1 time is, the more timely the temperature of the refrigerant of the refrigeration module can follow the frequency change of the variable frequency compressor, so that the measured module liquid supply temperature Ti can better represent the cooling capacity of the refrigeration module for the refrigerant fluid when the variable frequency compressor 11 is at the current operating frequency. If there is a refrigeration module 1 whose module liquid supply temperature Ti is greater than its set liquid supply temperature Tn, the operating frequency of the variable frequency compressor 11 of the refrigeration module 1 is increased, that is, for each refrigeration module, the operating frequency of the variable frequency compressor of the refrigeration module whose module liquid supply temperature Ti is less than its set liquid supply temperature Tn is not increased, and only the operating frequency of the variable frequency compressor of the refrigeration module 1 whose module liquid supply temperature Ti is greater than its set liquid supply temperature Tn is increased; step 212 includes: repeating step 211 until the module liquid supply temperature Ti of each refrigeration module 1 is less than its set liquid supply temperature Tn.

[0034] Step 300 includes: calculating the average value Pv of the working frequency of the variable frequency compressor 11 of each refrigeration module 1, and then adjusting the working frequency of the variable frequency compressor 11 of each refrigeration module 1 to the average value Pv. If the module liquid supply temperature Ti of each refrigeration module 1 whose working frequency is the average value Pv is lower than its liquid supply set temperature Tn, the variable frequency compressor 11 of each refrigeration module 1 currently working will work at the current working frequency. If the module liquid supply temperature Ti of a refrigeration module 1 is higher than its liquid supply set temperature Tn, the working frequency of the variable frequency compressor 11 of the refrigeration module 1 is increased, and then step 200 is executed.

[0035] In step 300, after the operation of completing the module liquid supply temperature Ti of each refrigeration module 1 in step 200 is completed and the module liquid supply temperature Ti is less than the set liquid supply temperature Tn, the frequency averaging operation is performed to average the working frequencies of the variable frequency compressors of each refrigeration module currently in operation. For example, if there are 4 refrigeration modules currently in operation, the frequencies of the variable frequency compressors of the 4 refrigeration modules are added and then divided by 4 to obtain the average value Pv, and then the working frequency of the variable frequency compressor 11 of each refrigeration module 1 is adjusted to Pv for operation. For this adjustment, the adjustment directions of different variable frequency compressors may be the same or different. For example, some variable frequency compressors are increased in frequency, while others may need to be decreased in frequency. After the frequency averaging operation is completed, the module liquid supply temperature Ti of the refrigeration fluid output by the module heat exchanger 14 of each refrigeration module 1 currently in operation whose variable frequency compressor 11 is located under the average value Pv is obtained, and then their respective set liquid supply temperatures Tn are compared and subsequent operations are performed.

[0036] The balanced control method of the modular refrigeration unit of this embodiment can make the variable frequency compressor 11 of each refrigeration module 1 work at the same and lower working frequency after the operation of step 200 and step 300, and at the same time, each refrigeration module 1 can ensure that the refrigeration effect of the refrigeration fluid meets the requirements under the working frequency. Therefore, the modular refrigeration unit can achieve a good working state with low energy consumption, low noise, and stable balance.

[0037] In some embodiments, step 100 further includes: raising the working frequency of the variable frequency compressor 11 of each refrigeration module 1 to the initial working stable frequency, and then executing step 200. The initial working stable frequency is the minimum working frequency when the variable frequency compressor 11 can work stably after starting, and the frequency is determined according to the model of the variable frequency compressor. In this embodiment, after the frequency of the variable frequency compressor 11 of the refrigeration module 1 is raised to the minimum working frequency after starting, the minimum working frequency is used as the current working frequency of the variable frequency compressor, and then the step 200 is entered to obtain the module supply liquid temperature Ti of the refrigeration fluid output by the module heat exchanger 14 of each refrigeration module 1 currently working when its variable frequency compressor 11 is at the minimum working frequency, and the subsequent steps of step 200 are performed. In this embodiment, by using the initial working stable frequency as the initial working frequency of the variable frequency compressor and performing subsequent frequency raising and the frequency averaging operation of step 300, the average value Pv obtained for the first time in the frequency averaging operation of step 300 can be made as small as possible, so that the balanced control method of the modular refrigeration unit of this embodiment can adapt to a wider range of heat loads.

[0038] In some embodiments, step 100 further includes: obtaining the temperature difference Tk between the inlet refrigeration fluid and the outlet refrigeration fluid of the total heat exchanger 23 when the variable frequency compressor 11 of each refrigeration module 1 is at the initial working stable frequency, judging whether the temperature difference Tk is greater than the first set temperature N1, and if it is judged that the temperature difference Tk is greater than the first set temperature N1, executing step 200. The first set temperature N1 is a temperature value used to judge the load size, which is set according to the cooling capacity of the modular refrigeration unit. When the temperature difference Tk is greater than the first set temperature N1, all refrigeration modules of the modular refrigeration unit need to be turned on. For example, the first set temperature N1 can be set to 10°C. In this embodiment, by judging that the temperature difference Tk is greater than the first set temperature N1, it can be judged that the cooling demand of the heat load is large, and each refrigeration module of the modular refrigeration unit needs to work normally.

[0039] In some embodiments, step 100 further includes: obtaining a temperature difference Tk between the inlet refrigeration fluid and the outlet refrigeration fluid of the total heat exchanger 23 when the variable frequency compressor 11 of each refrigeration module 1 is at the initial working stable frequency, judging whether the temperature difference Tk is greater than the first set temperature N1, and if the temperature difference Tk is judged to be less than the first set temperature N1, executing step 210, and then judging whether the temperature difference Tk is greater than the first set temperature N1, and if the temperature difference Tk is judged to be greater than the first set temperature N1, executing step 200. In this embodiment, when it is preliminarily judged that the temperature difference Tk is less than the first set temperature N1, the possible reason is that the heat load demand is small, or the refrigeration capacity of the refrigeration module is insufficiently turned on. By executing step 210, after the refrigeration capacity of each refrigeration module reaches sufficient, the temperature difference Tk and the first set temperature N1 are judged again. If the temperature difference Tk is judged to be greater than the first set temperature N1, it can be more accurately judged that there is a large cooling demand for the heat load.

[0040] In some embodiments, step 100 further includes: obtaining the temperature difference Tk between the inlet refrigeration fluid and the outlet refrigeration fluid of the total heat exchanger 23 when the variable frequency compressor 11 of each refrigeration module 1 is at the initial working stable frequency, judging whether the temperature difference Tk is greater than the first set temperature N1, if the temperature difference Tk is judged to be less than the first set temperature N1, executing step 210, then judging whether the temperature difference Tk is greater than the first set temperature N1, if the temperature difference Tk is judged to be less than the first set temperature N1, then judging whether Tk is less than the second set temperature N2, if the temperature difference Tk is judged to be greater than the second set temperature N2, then shutting down at least one refrigeration module 1, then executing step 200, if the temperature difference Tk is judged to be less than the second set temperature N2, shutting down the modular refrigeration unit. The second set temperature N2 is another temperature value used to judge the load size, which is set according to the cooling capacity of the modular refrigeration unit, for example, the second set temperature N2 can be set to 5°C, when the temperature difference Tk is less than the second set temperature N2, it indicates that its cooling demand is very weak, and the modular refrigeration unit does not need to work, so the modular refrigeration unit can be shut down. All refrigeration modules of the modular refrigeration unit need to be turned on. In this embodiment, by judging whether Tk is less than the second set temperature N2, it is possible to more accurately determine whether to perform a reduction operation or a shutdown operation on the refrigeration module 1 of the modular refrigeration unit, thereby more accurately judging the cooling demand of the heat load, so that the refrigeration capacity of the modular refrigeration unit is more matched with the cooling demand of the heat load.

[0041] In some embodiments, the balanced control method of the modular refrigeration unit further includes step 400 executed after step 300, and step 400 includes: obtaining the main liquid supply temperature Tm of the refrigeration fluid at the inlet of the total heat exchanger 23, judging the magnitude of the main liquid supply temperature Tm and the main liquid supply demand temperature Tg, and if it is judged that Tm is greater than Tg, shutting down the modular refrigeration unit. The main liquid supply demand temperature is the temperature at which the refrigeration fluid entering the total heat exchanger has sufficient cooling capacity for the heat load. The magnitude of the main liquid supply demand temperature Tg is directly related to the liquid supply setting temperature Tn of each refrigeration module. According to the setting of the main liquid supply demand temperature Tg, the setting of the liquid supply setting temperature Tn can be allocated, that is, when the module liquid supply temperature Ti of each refrigeration module is less than the liquid supply setting temperature Tn, the main liquid supply temperature Tm can also be guaranteed to be less than the main liquid supply demand temperature Tg. In this embodiment, after step 300, it is judged that Tm is greater than Tg, which can reflect that there is a fault in the modular refrigeration unit. At this time, the modular refrigeration unit can be shut down in time for fault finding and maintenance.

[0042] In some embodiments, a modular refrigeration unit is also disclosed, which uses any of the above-mentioned balanced control methods for modular refrigeration units. The modular refrigeration unit includes: a fluid pipeline, a refrigeration fluid in the fluid pipeline, a total heat exchanger 23 for passing the refrigeration fluid to cool the heat load, and a plurality of refrigeration modules 1. The refrigeration module 1 includes a variable frequency compressor 11, a condenser 12, an expansion valve 13, and a module heat exchanger 14 for cooling the refrigeration fluid connected in sequence. The fluid pipeline connects the module heat exchanger 14 and the total heat exchanger 23 of the refrigeration module 1 so that the refrigeration fluid flows between the module heat exchanger 14 and the total heat exchanger 23. The refrigeration module 1 also includes a temperature detection sensor 15 for detecting the temperature of the refrigeration fluid output by the module heat exchanger 14. The modular refrigeration unit of this embodiment can apply any of the above-mentioned balanced control methods for modular refrigeration units to obtain the corresponding beneficial effects of the above-mentioned balanced control methods for modular refrigeration units.

[0043] In some embodiments, Figure 2 As shown, the modular refrigeration unit also includes a first temperature sensor 21 for detecting the temperature of the refrigeration fluid at the inlet of the total heat exchanger 23 and a second temperature sensor 22 for detecting the temperature of the refrigeration fluid at the outlet thereof. By providing the first temperature sensor 21 and the second temperature sensor 22, this embodiment can conveniently and accurately obtain the temperature of the refrigeration fluid at the inlet of the total heat exchanger and the temperature of the refrigeration fluid at the outlet, and can accurately obtain the temperature difference Tk between the refrigeration fluid at the inlet and the refrigeration fluid at the outlet of the total heat exchanger 23, so that the balanced control method of the modular refrigeration unit of this embodiment can be reliably and effectively implemented.

[0044] In some embodiments, the refrigeration module 1 includes a module controller connected to the variable frequency compressor 11 and the temperature detection sensor 15 by signal, and the modular refrigeration unit includes a main controller connected to the module controller by signal, the module controller is configured to adjust the working frequency of the variable frequency compressor 11 according to the detection result of the temperature detection sensor 15, and the main controller is configured to calculate the average value of the working frequency of the variable frequency compressor 11 of each refrigeration module 1 and send to the module controller to adjust the frequency of the corresponding variable frequency compressor 11. That is, each refrigeration module is provided with a module controller, and then a main controller is also provided to control each module controller. In this embodiment, when performing the frequency increase operation of step 200, each refrigeration module is mainly controlled by the module controller, and when performing the frequency equalization operation, it is jointly operated by the main controller and the module controller. By setting the controller separately, when there is a communication failure between the main controller and the module controller, each module controller can also independently control its own refrigeration module to ensure that the refrigeration module meets the requirements of its own refrigeration capacity and the refrigeration capacity of the modular refrigeration unit can meet the requirements.

[0045] In some embodiments, the modular refrigeration unit further includes a manual operation control panel connected to the main controller signal, and the manual operation control panel is configured to manually operate and transmit control signals to the module controller through the main controller to control the start and stop of the modular refrigeration unit or set the liquid supply set temperature of the refrigeration module 1. This embodiment can flexibly and conveniently control the start and stop of the modular refrigeration unit or set the liquid supply set temperature of the refrigeration module 1 by setting the manual operation control panel.

[0046] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, ordinary technicians in the field should understand that the specific implementation methods of the present invention can still be modified or some technical features can be replaced by equivalents without departing from the spirit of the technical solution of the present invention, which should be included in the scope of the technical solution for protection of the present invention.

Claims

1. A balanced control method for a modular refrigeration unit, characterized in that: The modular refrigeration unit comprises a fluid pipeline, a refrigeration fluid in the fluid pipeline, a main heat exchanger (23) for passing the refrigeration fluid to cool the heat load, and a plurality of refrigeration modules, wherein the refrigeration module comprises a variable frequency compressor (11), a condenser (12), an expansion valve (13), and a module heat exchanger (14) for cooling the refrigeration fluid, which are connected in sequence, the fluid pipeline connects the module heat exchanger (14) of the refrigeration module with the main heat exchanger (23) so that the refrigeration fluid flows between the module heat exchanger (14) and the main heat exchanger (23), and the balancing control method of the modular refrigeration unit comprises: Step 100, start each refrigeration module, and then execute step 200; Step 200 includes step 210, wherein step 210 includes step 211 and step 212, wherein step 211 includes: obtaining a module liquid supply temperature Ti of the refrigeration fluid output by the module heat exchanger (14) of each refrigeration module currently in operation and whose variable frequency compressor (11) is at the current operating frequency, determining the magnitude of the module liquid supply temperature Ti of each refrigeration module and its liquid supply setting temperature Tn, and if the module liquid supply temperature Ti of any refrigeration module is greater than its liquid supply setting temperature Tn, then increasing the operating frequency of the variable frequency compressor (11) of the refrigeration module, and step 212 includes: repeatedly executing step 211 until the module liquid supply temperature Ti of each refrigeration module is less than its liquid supply setting temperature Tn, and then executing step 300; Step 300 comprises: calculating an average value Pv of the operating frequency of the variable frequency compressor (11) of each refrigeration module, and then adjusting the operating frequency of the variable frequency compressor (11) of each refrigeration module to the average value Pv; if the module liquid supply temperature Ti of each refrigeration module whose operating frequency of the variable frequency compressor (11) is the average value Pv is less than its liquid supply set temperature Tn, then the variable frequency compressor (11) of each refrigeration module currently operating operates at the current operating frequency; if the module liquid supply temperature Ti of a refrigeration module is greater than its liquid supply set temperature Tn, then the operating frequency of the variable frequency compressor (11) of the refrigeration module is increased, and then step 200 is executed.

2. The balanced control method of a modular refrigeration unit according to claim 1, characterized in that: The step 100 further comprises: increasing the operating frequency of the variable frequency compressor (11) of each refrigeration module to an initial stable operating frequency, and then executing step 200.

3. The balanced control method of a modular refrigeration unit according to claim 2, characterized in that: The step 100 further comprises: obtaining a temperature difference Tk between the inlet refrigeration fluid and the outlet refrigeration fluid of the total heat exchanger (23) when the variable frequency compressor (11) of each refrigeration module is at an initial working stable frequency, judging whether the temperature difference Tk is greater than a first set temperature N1, and if the temperature difference Tk is judged to be greater than the first set temperature N1, executing step 200.

4. The balanced control method of a modular refrigeration unit according to claim 2, characterized in that: The step 100 further comprises: obtaining a temperature difference Tk between the inlet refrigeration fluid and the outlet refrigeration fluid of the total heat exchanger (23) when the variable frequency compressor (11) of each refrigeration module is at the initial working stable frequency, judging whether the temperature difference Tk is greater than a first set temperature N1, if the temperature difference Tk is judged to be less than the first set temperature N1, executing step 210, and then judging whether the temperature difference Tk is greater than the first set temperature N1, if the temperature difference Tk is judged to be greater than the first set temperature N1, executing step 200.

5. The method for balanced control of a modular refrigeration unit according to claim 2, characterized in that: The step 100 further comprises: obtaining a temperature difference Tk between the inlet refrigeration fluid and the outlet refrigeration fluid of the total heat exchanger (23) when the variable frequency compressor (11) of each refrigeration module is at the initial working stable frequency, judging whether the temperature difference Tk is greater than a first set temperature N1; if the temperature difference Tk is judged to be less than the first set temperature N1, executing step 210, then judging whether the temperature difference Tk is greater than the first set temperature N1; if the temperature difference Tk is judged to be less than the first set temperature N1, then judging whether Tk is less than a second set temperature N2; if the temperature difference Tk is judged to be greater than the second set temperature N2, shutting down at least one refrigeration module, and then executing step 200; if the temperature difference Tk is judged to be less than the second set temperature N2, shutting down the modular refrigeration unit.

6. The balanced control method for a modular refrigeration unit according to any one of claims 1 to 5, characterized in that: The modular refrigeration unit balance control method further includes step 400 executed after step 300, wherein step 400 includes: obtaining a main liquid supply temperature Tm of the refrigeration fluid at the inlet of the total heat exchanger (23), determining the magnitude of the main liquid supply temperature Tm and the main liquid supply demand temperature Tg, and if it is determined that Tm is greater than Tg, shutting down the modular refrigeration unit.

7. A modular refrigeration unit, characterized in that: A method for balancing control of a modular refrigeration unit according to any one of claims 1 to 6 is applied, wherein the modular refrigeration unit comprises: a fluid pipeline, a refrigeration fluid in the fluid pipeline, a total heat exchanger (23) for passing the refrigeration fluid to cool a heat load, and a plurality of refrigeration modules, wherein the refrigeration module comprises a variable frequency compressor (11), a condenser (12), an expansion valve (13), and a module heat exchanger (14) for cooling the refrigeration fluid connected in sequence, wherein the fluid pipeline connects the module heat exchanger (14) and the total heat exchanger (23) of the refrigeration module so that the refrigeration fluid flows between the module heat exchanger (14) and the total heat exchanger (23), and the refrigeration module further comprises a temperature detection sensor (15) for detecting the temperature of the refrigeration fluid output by the module heat exchanger (14).

8. The modular refrigeration unit according to claim 7, characterized in that: The modular refrigeration unit further comprises a first temperature sensor (21) for detecting the temperature of the refrigeration fluid at the inlet of the main heat exchanger (23) and a second temperature sensor (22) for detecting the temperature of the refrigeration fluid at the outlet thereof.

9. The modular refrigeration unit according to claim 7, characterized in that: The refrigeration module comprises a module controller connected to the variable frequency compressor (11) and the temperature detection sensor (15) by signal, the modular refrigeration unit comprises a main controller connected to the module controller by signal, the module controller is configured to adjust the operating frequency of the variable frequency compressor (11) according to the detection result of the temperature detection sensor (15), and the main controller is configured to calculate the average value of the operating frequency of the variable frequency compressor (11) of each refrigeration module and send a signal to the module controller to adjust the frequency of the corresponding variable frequency compressor (11).

10. The modular refrigeration unit according to claim 7, characterized in that: The modular refrigeration unit also includes a manual operation control panel connected to the main controller signal, and the manual operation control panel is configured to be used for manual operation and to transmit control signals to the module controller through the main controller to control the startup and shutdown of the modular refrigeration unit or to set the liquid supply set temperature of the refrigeration module.

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