CN118310219A - Control method and device for magnetic suspension water chilling unit, water chilling unit and medium - Google Patents

Abstract

The application relates to the technical field of refrigeration equipment, and discloses a control method for a magnetic suspension water chilling unit, wherein the magnetic suspension water chilling unit comprises a magnetic suspension compressor, a condenser and a cooling pipeline, the condenser, the cooling pipeline and the magnetic suspension compressor are connected in series, the cooling pipeline is provided with a flow regulating device for regulating the flow of a refrigerant, and the method comprises the following steps: acquiring operation phase information and operation parameter values of the magnetic suspension water chilling unit; determining flow judgment conditions corresponding to the operation stage information according to the operation stage information; and executing flow regulation operation through the flow regulation device under the condition that the operation parameter value meets the flow judgment condition. The method can improve the running stability of the magnetic suspension water chilling unit system in different stages. The application also discloses a control device for the magnetic suspension water chilling unit, the water chilling unit and a medium.

Description

Control method and device for magnetic suspension chiller, chiller, medium

Technical Field

The present application relates to the technical field of refrigeration equipment, for example, to a control method and device for a magnetic levitation chiller, a chiller, and a medium.

Background technique

At present, centrifugal chillers are widely used in the construction and industrial fields. The types of compressors equipped with centrifugal chillers include magnetic levitation compressors and gas levitation compressors. The magnetic levitation compressor is equipped with electronic components such as frequency converters and drive motors, as well as electromagnetic bearings, and it uses variable frequency control for refrigeration. A centrifugal chiller equipped with a magnetic levitation compressor is called a magnetic levitation chiller. Among them, magnetic levitation chillers are widely used in the chemical industry (for example, the alumina industry, the edible fungus cultivation industry) and the data industry. For the alumina industry and the edible fungus cultivation industry, there is a demand for year-round refrigeration operation of magnetic levitation chillers.

When the magnetic levitation chiller operates for cooling throughout the year, there is a high chilled water outlet temperature (about 18°C) and a high suction pressure of the compressor, resulting in a low compression ratio of the compressor. Electronic components such as the inverter and drive motor require cooling with liquid refrigerant. When the compression ratio of the compressor is low, liquid refrigerant cannot be supplied to the compressor, and the refrigerant cooling needs of electronic components such as the inverter and drive motor cannot be met, resulting in insufficient cooling of the compressor. During the startup phase of the magnetic levitation chiller and the long-term stable operation phase, due to insufficient cooling of the compressor, electronic components such as the inverter and drive motor will be damaged, and even electromagnetic bearing failures may occur, which is not conducive to the stable operation of the magnetic levitation chiller.

Related art discloses a compressor cooling control method for an air conditioning unit, wherein the air conditioning unit comprises a compressor, a condenser, and an evaporator connected in sequence, an expansion valve is arranged on the liquid pipe between the condenser and the evaporator, and the condenser is connected to the cooling port of the compressor through a cooling pipe. The control method comprises: obtaining the evaporator inlet water temperature T ₁ and the condenser inlet water temperature T ₂ ; calculating the temperature difference △T=T ₂ -T ₁ ; judging whether the temperature difference △T is ≤ a set temperature difference threshold; if so, determining a first set compression ratio value according to the evaporator inlet water temperature T ₁ , calculating an absolute compression ratio, and judging whether the absolute compression ratio is ≤ the first set compression ratio value; if so, entering the suction superheat control; in the suction superheat control, determining a suction superheat target value according to the evaporator inlet water temperature T ₁ , and controlling the opening of the expansion valve according to the suction superheat target value.

In the process of implementing the embodiments of the present disclosure, it is found that there are at least the following problems in the related art:

The technical solution adopted by the related technology is applicable to the startup stage of the magnetic levitation chiller. However, when the magnetic levitation chiller is in the operation stage after startup, the temperature difference between the evaporator inlet water temperature and the condenser outlet water temperature alone cannot accurately reflect the cooling capacity of the compressor. Therefore, the above compressor cooling control method cannot perform differentiated cooling operations for magnetic levitation compressors at different stages, and it is difficult to ensure the stability of the system operation at different stages.

It should be noted that the information disclosed in the above background technology section is only used to enhance the understanding of the background of the present application, and therefore may include information that does not constitute the prior art known to ordinary technicians in the field.

Summary of the invention

In order to provide a basic understanding of some aspects of the disclosed embodiments, a brief summary is given below. The summary is not an extensive review, nor is it intended to identify key/critical components or delineate the scope of protection of these embodiments, but rather serves as a prelude to the detailed description that follows.

The embodiments of the present disclosure provide a control method, device, chiller and medium for a magnetic levitation chiller to improve the stability of the operation of the magnetic levitation chiller system at different stages.

In some embodiments, the magnetic levitation chiller includes a magnetic levitation compressor, a condenser and a cooling pipeline, the condenser, the cooling pipeline and the magnetic levitation compressor are connected in series, and the cooling pipeline is configured with a flow regulating device for regulating the flow of refrigerant. The method includes: obtaining the operating stage information and operating parameter value of the magnetic levitation chiller; determining the flow judgment condition corresponding to the operating stage information according to the operating stage information; and performing the flow regulation operation through the flow regulating device when the operating parameter value meets the flow judgment condition.

In some embodiments, the device includes: a processor and a memory storing program instructions, and the processor is configured to execute the control method for the magnetic levitation chiller as described above when running the program instructions.

In some embodiments, the magnetic levitation chiller includes: a magnetic levitation compressor; a cooling pipeline, equipped with a flow regulating device for regulating the flow of refrigerant; a condenser, connected in series with the cooling pipeline and the magnetic levitation compressor; and a control device for the magnetic levitation chiller as described above, installed in the cooling pipeline.

In some embodiments, the storage medium stores program instructions, and when the program instructions are run, they execute the control method for the magnetic levitation chiller as described above.

The control method, device, chiller and medium for a magnetic levitation chiller provided in the embodiments of the present disclosure can achieve the following technical effects:

The disclosed embodiment determines the corresponding flow judgment condition according to the operation stage information of the magnetic levitation chiller. When the operation parameter value satisfies the flow judgment condition, the flow regulation operation is performed using the flow regulation device. The disclosed embodiment can perform corresponding flow judgment and flow regulation operation according to the cooling condition of the compressor at different operation stages, so as to perform differentiated cooling operations for the magnetic levitation compressor at different operation stages, which is conducive to improving the stability of the operation of the magnetic levitation chiller system at different stages.

The above general description and the following description are exemplary and explanatory only and are not intended to limit the present application.

BRIEF DESCRIPTION OF THE DRAWINGS

One or more embodiments are exemplarily described by corresponding drawings, which do not limit the embodiments. Elements with the same reference numerals in the drawings are shown as similar elements, and the drawings do not constitute a scale limitation, and wherein:

FIG1 is a system schematic diagram of a magnetic suspension chiller;

FIG2 is another system schematic diagram of a magnetic suspension chiller;

FIG3 is a schematic diagram of a control method for a magnetic suspension chiller provided by an embodiment of the present disclosure;

FIG4 is a schematic diagram of another control method for a magnetic suspension chiller provided by an embodiment of the present disclosure;

FIG5 is a schematic diagram of another control method for a magnetic suspension chiller provided by an embodiment of the present disclosure;

FIG6 is a schematic diagram of another control method for a magnetic suspension chiller provided by an embodiment of the present disclosure;

FIG7 is a schematic diagram of a control device for a magnetic suspension chiller provided by an embodiment of the present disclosure;

FIG8 is a schematic diagram of another control device for a magnetic suspension chiller provided by an embodiment of the present disclosure;

FIG. 9 is a schematic diagram of a magnetically suspended chiller provided in an embodiment of the present disclosure.

Reference numerals:

10: compressor; 20: condenser; 30: evaporator; 40: cooling pipeline;

501: variable frequency refrigerant pump; 502: one-way valve; 503: dry filter;

504: first ball valve; 505: second ball valve; 506: sight glass;

601: Constant frequency refrigerant pump; 602: Electronic expansion valve.

Detailed ways

In order to be able to understand the features and technical contents of the embodiments of the present disclosure in more detail, the implementation of the embodiments of the present disclosure is described in detail below in conjunction with the accompanying drawings. The attached drawings are for reference only and are not used to limit the embodiments of the present disclosure. In the following technical description, for the convenience of explanation, a full understanding of the disclosed embodiments is provided through multiple details. However, one or more embodiments can still be implemented without these details. In other cases, to simplify the drawings, well-known structures and devices can be simplified for display.

The terms "first", "second", etc. in the specification and claims of the embodiments of the present disclosure and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the terms used in this way can be interchanged where appropriate, so that the embodiments of the embodiments of the present disclosure described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions.

Unless otherwise stated, the term "plurality" means two or more.

In the embodiment of the present disclosure, the character "/" indicates that the preceding and following objects are in an "or" relationship. For example, A/B indicates: A or B.

The term "and/or" is a description of the association relationship between objects, indicating that three relationships can exist. For example, A and/or B means: A or B, or, A and B.

The term "correspondence" may refer to an association relationship or a binding relationship. The correspondence between A and B means that there is an association relationship or a binding relationship between A and B.

The embodiment of the present disclosure provides a magnetic suspension chiller including a compressor 10, a condenser 20, an evaporator 30 and a cooling pipeline 40. The condenser 20 and the cooling pipeline 40 are connected in series with the compressor 10. The cooling pipeline 40 is provided with a flow regulating device for regulating the flow of the refrigerant.

FIG1 shows a schematic diagram of a system of a magnetic levitation chiller. As shown in FIG1 , the cooling pipeline 40 includes a variable frequency refrigerant pump 501 and a one-way valve 502 connected in parallel with the variable frequency refrigerant pump 501. The one-way valve 502 is used to be controlled to open when the variable frequency refrigerant pump 501 is turned off, so as to supply liquid to the compressor 10 and to control the refrigerant to flow from the condenser 2 to the compressor 10 to avoid refrigerant backflow. The one-way valve 502 is normally open during the startup stage and the stable operation stage of the magnetic levitation chiller.

Optionally, the cooling line 40 further includes a filter dryer 503, a first ball valve 504, a second ball valve 505 and a sight glass 506. The first ball valve 504 and the variable frequency refrigerant pump 501, the second ball valve 505 and the sight glass 506 are sequentially connected in series along the refrigerant flow direction. The first ball valve 504 and the second ball valve 505 are controlled to be closed during the cleaning phase of the filter dryer 503 to drain the refrigerant in the cooling line 40, to avoid the refrigerant in the compressor 1, the condenser 20 and the evaporator 30 from being recycled, and to reduce the waste of refrigerant. The sight glass 506 is used to check the refrigerant flow, which is conducive to troubleshooting system failures.

FIG2 shows another system schematic diagram of the magnetic levitation chiller. As shown in FIG2 , the cooling pipeline 40 includes a series branch consisting of a fixed-frequency refrigerant pump 601 and an electronic expansion valve 602 connected in series with the fixed-frequency refrigerant pump 501, and a one-way valve 502 connected in parallel with the series branch. The one-way valve 502 is used to be controlled to open when the electronic expansion valve 602 is closed to supply liquid to the compressor 10 and to control the refrigerant to flow from the condenser 2 to the compressor 10 to avoid refrigerant backflow. The one-way valve 502 is normally open during the startup stage and the stable operation stage of the magnetic levitation chiller.

Optionally, the cooling pipeline 40 further includes a drying filter 503, a first ball valve 504, a second ball valve 505 and a sight glass 506. The first ball valve 504 and the variable frequency refrigerant pump 501, the second ball valve 505 and the sight glass 506 are sequentially connected in series along the refrigerant flow direction. In the disclosed embodiment, the functions of the first ball valve 504, the second ball valve 505 and the sight glass 506 are the same as those described above and are not described in detail herein.

Based on the above-mentioned magnetic suspension chiller system, in combination with FIG3 , the present disclosure provides a control method for a magnetic suspension chiller, the method comprising:

S01, the processor obtains the operation stage information and operation parameter values of the magnetic levitation chiller.

S02: The processor determines a flow determination condition corresponding to the operation stage information according to the operation stage information.

S03, when the operating parameter value meets the flow judgment condition, the processor performs a flow regulation operation through the flow regulation device.

The control method for a magnetic levitation chiller provided by an embodiment of the present disclosure is adopted. The embodiment of the present disclosure determines the corresponding flow judgment condition according to the operation stage information of the magnetic levitation chiller. When the operation parameter value meets the flow judgment condition, the flow regulation operation is performed using a flow regulating device. The embodiment of the present disclosure can perform corresponding flow judgments and flow regulation operations according to the cooling conditions of the compressor at different operation stages, so as to perform differentiated cooling operations for the magnetic levitation compressor at different operation stages, which is conducive to improving the stability of the operation of the magnetic levitation chiller system at different stages.

It should be noted that when the magnetic levitation chiller is in the startup stage, the chilled water temperature and the cooling water temperature have the following two conditions: the first is the normal working condition, the chilled water temperature and the cooling water temperature are both over 30°C; the second is the reverse working condition, the absolute value of the difference between the chilled water temperature and the cooling water temperature is greater than or equal to 5°C. In the first case, the rate of increase of the compression ratio of the magnetic levitation compressor is within the controllable range. In the second case, the rate of increase of the compression ratio of the magnetic levitation compressor is low, resulting in insufficient cooling capacity of the magnetic levitation compressor, and the inverter temperature value is as high as 70°C. Therefore, for both of the above working conditions, there is a need to improve the cooling capacity of the magnetic levitation compressor. For the second reverse working condition mentioned above, it is necessary to quickly improve the cooling capacity of the magnetic levitation compressor. In addition, the stable operation stage refers to the stage corresponding to the preset duration after the magnetic levitation chiller is started. The preset duration is greater than or equal to 15 minutes.

Optionally, the processor determines, according to the running stage information, a flow determination condition corresponding to the running stage information, including:

When the operation stage information indicates that the system is in the startup stage, the processor determines the chilled water temperature and the cooling water temperature as target operation parameter values, and determines the first preset condition as a flow determination condition.

When the operation stage information indicator is in a stable operation stage, the processor determines the compression ratio and load of the magnetic levitation compressor and the inverter temperature value as the target operation parameter values, and determines the second preset condition as the flow judgment condition.

In this way, the cooling capacity of the magnetic levitation compressor is known through different types of operating parameters when the magnetic levitation chiller is in the startup stage and the stable operation stage. As mentioned above, the cooling capacity of the magnetic levitation compressor is usually judged according to the temperature of the chilled water and the temperature of the cooling water during the startup stage. When the magnetic levitation chiller is in the stable operation stage, the temperature of the chilled water and the temperature of the cooling water are relatively stable and the cooling capacity of the compressor is also relatively stable. At this time, the cooling capacity of the magnetic levitation compressor can be indirectly known through the compression ratio and load of the compressor and the temperature value of the inverter. Therefore, the embodiment of the present disclosure can obtain the cooling condition of the magnetic levitation compressor through different operating parameters according to the conditions of the magnetic levitation chiller at different stages, and provide an accurate basis for subsequent flow regulation operations.

Optionally, the compression ratio is a ratio of an exhaust pressure value to an intake pressure value, wherein the exhaust pressure value represents an absolute exhaust pressure value, and the intake pressure value represents an absolute intake pressure value.

Optionally, when the operation stage information indicates that the operation stage is in the startup stage, the processor determines that the operation parameter value satisfies the first preset condition in the following manner:

The absolute value of the difference between the chilled water temperature and the cooling water temperature is greater than or equal to the preset water temperature deviation value. Or, the chilled water temperature is greater than or equal to the preset water temperature and the cooling water temperature is greater than or equal to the preset water temperature. The preset water temperature deviation value may be 5°C, 6°C, etc. The preset water temperature is 30°C.

In this way, when the magnetic levitation chiller is in the startup stage, it can be judged whether the magnetic levitation chiller is in normal working condition or reverse working condition according to the temperature of the chilled water and the temperature of the cooling water, providing an accurate basis for subsequent flow regulation operations.

Optionally, in combination with FIG. 4 , when the operating parameter value satisfies the first preset condition, the processor performs a flow regulation operation through the flow regulation device, including:

S11, the processor obtains the compression ratio.

S12, when the compression ratio is less than the preset lower limit compression ratio, the processor controls the flow regulating device to operate at the maximum flow value until the compression ratio is greater than or equal to the preset lower limit compression ratio. The preset lower limit compression ratio represents the critical value of whether the magnetic suspension compressor is sufficiently cooled. The preset lower limit compression ratio may be 1.5.

S13, the processor obtains the pressure value of the magnetic suspension compressor and the inverter temperature value when the compression ratio is greater than or equal to the preset upper limit compression ratio. The preset upper limit compression ratio represents the compression ratio threshold value when the flow regulating device switches from the maximum flow value to the dynamic flow regulating stage. The preset upper limit compression ratio is greater than the preset lower limit pressure. For example, the preset upper limit compression ratio can be 1.6.

S14, when the pressure value and the inverter temperature value indicate that the preset termination condition is not satisfied, the processor controls the flow regulating device to regulate the flow until the preset termination condition is satisfied.

The preset termination condition is that the suction pressure value is within the first pressure range, the exhaust pressure value is within the second pressure range, and the inverter temperature value is within the first preset temperature range. The first pressure range is 180kPa to 500kPa, the second pressure range is 500kPa to 1050kPa, and the first preset temperature range is 30℃ to 70℃.

In this way, when the operating parameter value meets the first preset condition, it is determined that the cooling capacity of the magnetic levitation compressor needs to be increased. If the compression ratio is less than the preset lower limit compression ratio, it indicates that the magnetic levitation compressor is below the critical value of sufficient cooling, and it is necessary to turn on the flow regulating device to operate at the maximum flow value to ensure that the compression ratio of the magnetic levitation compressor quickly rises to the preset lower limit compression ratio. After the compression ratio of the magnetic levitation compressor continues to rise to the preset upper limit compression ratio, the flow regulating device does not need to operate at the maximum flow value. At this time, it enters the dynamic flow regulation stage.

Therefore, the disclosed embodiment can determine whether the cooling of the magnetic levitation compressor is sufficient based on different types of parameters associated with the magnetic levitation compressor, and use a flow regulating device to accurately adjust the flow of the refrigerant in the cooling pipeline according to the above cooling conditions, so as to perform precise cooling operations on the magnetic levitation compressor during the startup phase, and further improve the stability of the operation of the magnetic levitation chiller system during the startup phase.

Optionally, in combination with FIG. 5 , in step S14, the processor controls the flow regulating device to regulate the flow, including:

S21, the processor obtains the refrigerant flow Q of the cooling pipeline and the load de of the magnetic levitation compressor.

S22, when the refrigerant flow rate Q is within a preset flow rate range and the load de is within a preset load range, the processor controls the flow regulating device to stop regulating the flow rate.

S23, when the refrigerant flow rate Q is outside the preset flow rate range and the load de is within the preset load range, the processor controls the flow regulating device to fine-tune the flow rate so that the adjusted refrigerant flow rate Q is within the preset flow rate range.

The preset flow rate range can be determined according to the model of the magnetic suspension compressor. As an example, the preset flow rate range is 0.048 to 0.306 m ³ /h (cubic meters per hour). The preset load range is 0% to 100%.

In this way, accurate regulation of the flow rate is achieved, and reliable regulation of the cooling capacity of the magnetic levitation compressor within a preset load range is achieved.

Optionally, when the operation stage information indicates that the system is in a stable operation stage and the operation parameter value satisfies a second preset condition, performing a flow regulation operation through a flow regulation device includes:

When the load is greater than or equal to the critical load threshold and the compression ratio is outside the first reference range, the processor controls the flow regulating device to open. Or,

When the load is greater than or equal to the critical load threshold and the inverter temperature value is outside the second reference range, the processor controls the flow regulating device to turn on. Or,

When the load is less than the critical load threshold, the processor controls the flow regulating device to turn on, wherein the critical load threshold may be 30% to 40%.

In this way, when the load is greater than or equal to the critical load threshold and the compression ratio is outside the preset compression ratio range, or when the load is greater than or equal to the critical load threshold and the inverter temperature value is outside the second preset temperature range, or when the load is less than the critical load threshold, it indicates that the magnetic levitation compressor is at risk of insufficient cooling. At this time, by controlling the flow regulating device to open, the cooling rate of the magnetic levitation compressor can be increased, thereby performing precise cooling operations for the magnetic levitation compressor in the stable operation stage, and further improving the stability of the magnetic levitation chiller system in the stable operation stage.

Optionally, the processor performs the flow regulation operation through the flow regulation device, further comprising:

When the load is greater than or equal to the critical load threshold and less than or equal to 100%, the processor controls the flow regulating device to be closed if the compression ratio is within the first reference range and the inverter temperature value is within the second reference range.

In this way, in the embodiment of the present disclosure, when the load of the magnetic levitation compressor is greater than or equal to the critical load threshold and within the full load, it is determined whether the compression ratio and the inverter temperature are respectively within their respective reference ranges. If they are, it indicates that the compressor is sufficiently cooled. At this time, the flow regulating device is controlled to be closed. The power consumption of the cooling pipeline is reduced, and the energy efficiency of the magnetic levitation chiller is improved.

Optionally, in combination with FIG6 , the first reference range and the second reference range are determined in the following manner:

S31, the processor controls the magnetic suspension chiller to operate at full load, wherein full load operation means that the load is 100%.

S32, when the processor is running at full load and the water temperature is at a set working condition, the processor obtains the current compression ratio and the current inverter temperature value.

S33, the processor selects a compression ratio range corresponding to the current compression ratio as a first reference range, and selects a second preset temperature range corresponding to the current inverter temperature value as a second reference range.

Among them, the first reference range and the second reference range indicate that when the load is 100%, the water temperature is stable in the corresponding reference range under the set working condition. The water temperature includes the chilled water temperature and the cooling water temperature. The set working condition indicates the working condition where the fluctuation deviation value of the chilled water temperature and the fluctuation deviation value of the cooling water temperature are both less than or equal to 2°C. As an example, the first reference range is [1.9-ΔCR, 1.9+ΔCR], ΔCR represents the preset compression ratio deviation value, and 0<ΔCR≤0.1. For example, ΔCR can be 0.02, 0.07, 0.1, etc. The second reference range is [42-ΔT, 42+ΔT]°C. ΔT represents the preset temperature deviation value, and 0≤ΔT≤13°C. For example, it can be 5°C, 10°C, etc. ΔCR and ΔT are determined by the model of the magnetic levitation compressor and actual measurement experience.

In this way, the embodiment of the present disclosure obtains the compression ratio range of the magnetic levitation compressor under a load of 100% and the second preset temperature range, so as to use their respective corresponding ranges as the reference ranges for subsequent flow regulation, which is beneficial to improving the accuracy of cooling pipeline flow regulation.

Optionally, the flow regulating device comprises a variable frequency refrigerant pump. The processor performs a flow regulating operation through the flow regulating device, including: performing the flow regulating operation by adjusting a rotation speed value of the variable frequency refrigerant pump.

or,

The flow regulating device includes a fixed-frequency refrigerant pump and an electronic expansion valve, which are connected in series. The processor performs a flow regulating operation through the flow regulating device, including: performing a flow regulating operation by adjusting the opening value of the electronic expansion valve.

In this way, when a variable frequency refrigerant pump is configured in the cooling pipeline, the flow rate can be regulated by adjusting the speed value of the variable frequency refrigerant pump. When a fixed frequency refrigerant pump is configured in the cooling pipeline, since the fixed frequency refrigerant pump cannot adjust its speed value, the embodiment of the present disclosure sets an electronic expansion valve between the drying filter and the fixed frequency refrigerant pump, thereby adjusting the opening value of the electronic expansion valve to achieve the regulation of the refrigerant flow of the fixed frequency refrigerant pump. In summary, the embodiment of the present disclosure can perform different parameter adjustments according to different types of refrigerant pumps configured in the cooling pipeline to achieve the regulation of the refrigerant flow rate.

In the practical application shown in FIG1 , the control method for the magnetic suspension chiller specifically performs the following steps:

S41, the processor obtains the operation stage information of the magnetic levitation chiller.

S42, the processor determines that it is in the startup phase, determines the chilled water temperature and the cooling water temperature as target operating parameter values, and determines the first preset condition as a flow determination condition.

S43, the processor determines that the absolute value of the difference between the chilled water temperature and the cooling water temperature is greater than or equal to 5°C, and determines that the magnetic levitation chiller is in a reverse condition, then controls the variable frequency refrigerant pump to operate at the maximum speed value, so that the compression ratio is rapidly increased to 1.5.

S44, the processor obtains the compression ratio again, and enters the dynamic flow regulation stage when the new compression ratio is greater than or equal to 1.6. Adjust the speed of the variable frequency refrigerant pump to slightly reduce the speed from the maximum speed value. At the same time, obtain the three parameters of the suction pressure value, exhaust pressure value, and inverter temperature value of the magnetic levitation compressor, and judge whether the suction pressure value is between 180kPa and 500kPa, whether the exhaust pressure value is between 500kPa and 1050kPa, and whether the inverter temperature value is between 30℃ and 70℃. It is judged that the suction pressure value is between 180kPa and 500kPa, the exhaust pressure value is between 500kPa and 1050kPa, and the inverter temperature value is between 30℃ and 70℃. All three conditions are met at the same time.

S45, the processor obtains the refrigerant flow Q of the cooling pipeline and the load de of the magnetic suspension compressor. After judging that the refrigerant flow Q is outside 0.048-0.306 ^m3 /h and the load de is within the preset load range of 0%-100%, the variable frequency refrigerant pump is controlled to fine-tune the speed value so that the adjusted refrigerant flow Q is within 0.048-0.306 ^m3 /h.

In the actual application shown in FIG2 , the control method for the magnetic suspension chiller specifically performs the following steps:

S51, the processor obtains the operation stage information of the magnetic levitation chiller.

S52, the processor determines that it is in a stable operation stage, determines the compression ratio and load of the magnetic suspension compressor and the inverter temperature value as target operation parameter values, and determines the second preset condition as a flow judgment condition.

S53, the processor controls the magnetic suspension chiller to operate at full load, and when the chiller is operating at full load and the water temperature is at the set working condition, obtains a current compression ratio of 1.9 and a current inverter temperature value of 42°C.

S54, the processor selects a compression ratio range corresponding to the current compression ratio as a first reference range [1.8, 2], and selects a second preset temperature range corresponding to the current inverter temperature value as a second reference range [30, 54]°C.

S55, the processor obtains the compression ratio, load and inverter temperature value in real time. After judging that the load is greater than or equal to 30% and the compression ratio is outside the first reference range [1.8, 2], the electronic expansion valve is controlled to open and remain open.

S56, after the unit has been running for 1 hour, the processor obtains the compression ratio, load and inverter temperature value again. After further determination, if the load is greater than or equal to 30% and the compression ratio is within the first reference range [1.8, 2], the electronic expansion valve is controlled to close.

As shown in FIG7 , an embodiment of the present disclosure provides a control device 200 for a magnetic levitation chiller, which includes a magnetic levitation compressor, a condenser, and a cooling pipeline. The condenser, the cooling pipeline, and the magnetic levitation compressor are connected in series. The cooling pipeline is provided with a flow regulating device for regulating the flow of the refrigerant. The device includes an acquisition module 201, a determination module 202, and an execution module 203. The acquisition module 201 is configured to acquire the operation stage information and the operation parameter value of the magnetic levitation chiller; the determination module 202 is configured to determine the flow judgment condition corresponding to the operation stage information according to the operation stage information; the execution module 203 is configured to perform the flow regulation operation through the flow regulating device when the operation parameter value meets the flow judgment condition.

The control device for a magnetic levitation chiller provided by the embodiment of the present disclosure can perform differentiated cooling operations on the magnetic levitation compressor at different operating stages, which is beneficial to improving the stability of the operation of the magnetic levitation chiller system at different stages.

As shown in FIG8 , the embodiment of the present disclosure provides a control device 300 for a magnetic levitation chiller, including a processor 100 and a memory 101. Optionally, the device may also include a communication interface 102 and a bus 103. The processor 100, the communication interface 102, and the memory 101 may communicate with each other through the bus 103. The communication interface 102 may be used for information transmission. The processor 100 may call the logic instructions in the memory 101 to execute the control method for a magnetic levitation chiller of the above embodiment.

In addition, the logic instructions in the memory 101 described above may be implemented in the form of software functional units and when sold or used as independent products, may be stored in a computer-readable storage medium.

The memory 101 is a computer-readable storage medium that can be used to store software programs and computer executable programs, such as program instructions/modules corresponding to the method in the embodiment of the present disclosure. The processor 100 executes functional applications and data processing by running the program instructions/modules stored in the memory 101, that is, the control method for the magnetic suspension chiller in the above embodiment is implemented.

The memory 101 may include a program storage area and a data storage area, wherein the program storage area may store an operating system and an application required for at least one function; the data storage area may store data created according to the use of the terminal device, etc. In addition, the memory 101 may include a high-speed random access memory and may also include a non-volatile memory.

As shown in FIG9 , the embodiment of the present disclosure provides a magnetic levitation chiller 100, including: a magnetic levitation compressor, a condenser, a cooling pipeline, and the above-mentioned control device 200 (300) for the magnetic levitation chiller. The control device 200 (300) for the magnetic levitation chiller is installed in the cooling pipeline. The installation relationship described here is not limited to placement inside the product, but also includes installation connections with other components of the product, including but not limited to physical connections, electrical connections or signal transmission connections. It can be understood by those skilled in the art that the control device 200 (300) for the magnetic levitation chiller can be adapted to a feasible product body, thereby realizing other feasible embodiments.

An embodiment of the present disclosure provides a computer-readable storage medium storing computer-executable instructions, wherein the computer-executable instructions are configured to execute the control method for a magnetically levitated chiller.

The computer-readable storage medium mentioned above may be a transient computer-readable storage medium or a non-transitory computer-readable storage medium.

The technical solution of the embodiment of the present disclosure can be embodied in the form of a software product, which is stored in a storage medium and includes one or more instructions for enabling a computer device (which may be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in the embodiment of the present disclosure. The aforementioned storage medium may be a non-transient storage medium, including: a USB flash drive, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a disk or an optical disk, and other media that can store program codes, or a transient storage medium.

The above description and accompanying drawings fully illustrate the embodiments of the present disclosure so that those skilled in the art can practice them. Other embodiments may include structural, logical, electrical, process and other changes. The embodiments represent possible changes only. Unless explicitly required, separate components and functions are optional, and the order of operation may vary. The parts and features of some embodiments may be included in or replace the parts and features of other embodiments. Moreover, the words used in this application are only used to describe the embodiments and are not used to limit the claims. As used in the description of the embodiments and claims, unless the context clearly indicates, the singular forms of "a", "an" and "the" are intended to include plural forms as well. Similarly, the term "and/or" as used in this application refers to any and all possible combinations of listings containing one or more associated ones. In addition, when used in the present application, the term "comprise" and its variants "comprises" and/or comprising refer to the presence of stated features, wholes, steps, operations, elements, and/or components, but do not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components and/or groups thereof. In the absence of further restrictions, the elements defined by the sentence "comprising a ..." do not exclude the presence of other identical elements in the process, method or device comprising the elements. In this article, each embodiment may focus on the differences from other embodiments, and the same and similar parts between the embodiments may refer to each other. For the methods, products, etc. disclosed in the embodiments, if they correspond to the method part disclosed in the embodiments, then the relevant parts can refer to the description of the method part.

Those skilled in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software may depend on the specific application and design constraints of the technical solution. The technicians may use different methods for each specific application to implement the described functions, but such implementations should not be considered to exceed the scope of the embodiments of the present disclosure. The technicians may clearly understand that for the convenience and simplicity of description, the specific working processes of the systems, devices and units described above can refer to the corresponding processes in the aforementioned method embodiments, and will not be repeated here.

In the embodiments disclosed herein, the disclosed methods and products (including but not limited to devices, equipment, etc.) can be implemented in other ways. For example, the device embodiments described above are only schematic. For example, the division of the units can be only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the coupling or direct coupling or communication connection between each other shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms. The units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the units may be selected according to actual needs to implement this embodiment. In addition, each functional unit in the embodiment of the present disclosure may be integrated in a processing unit, or each unit may exist physically alone, or two or more units may be integrated in one unit.

The flowchart and block diagram in the accompanying drawings show the possible architecture, function and operation of the system, method and computer program product according to the embodiment of the present disclosure. In this regard, each box in the flowchart or block diagram can represent a module, a program segment or a part of the code, and the module, the program segment or a part of the code contains one or more executable instructions for realizing the specified logical function. In some alternative implementations, the functions marked in the box can also occur in a different order from the order marked in the accompanying drawings. For example, two consecutive boxes can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, which can depend on the functions involved. In the description corresponding to the flowchart and the block diagram in the accompanying drawings, the operations or steps corresponding to different boxes can also occur in a different order from the order disclosed in the description, and sometimes there is no specific order between different operations or steps. For example, two consecutive operations or steps can actually be executed substantially in parallel, and they can sometimes be executed in the opposite order, which can depend on the functions involved. Each block in the block diagrams and/or flowcharts, and combinations of blocks in the block diagrams and/or flowcharts, may be implemented by a dedicated hardware-based system that performs the specified functions or actions, or may be implemented by a combination of dedicated hardware and computer instructions.

Claims (11)

1. A control method for a magnetic suspension chiller, characterized in that the magnetic suspension chiller comprises a magnetic suspension compressor, a condenser and a cooling pipeline, the condenser, the cooling pipeline and the magnetic suspension compressor are connected in series, and the cooling pipeline is provided with a flow regulating device for regulating the flow of refrigerant, the method comprising: Obtaining operation stage information and operation parameter values of the magnetic levitation chiller; According to the operation stage information, determining the flow judgment condition corresponding to the operation stage information; When the operating parameter value meets the flow judgment condition, the flow regulation operation is performed by the flow regulation device. 2. The method according to claim 1, characterized in that the step of determining the flow judgment condition corresponding to the operation stage information according to the operation stage information comprises: When the operation stage information indicates that the system is in the startup stage, the chilled water temperature and the cooling water temperature are determined as target operation parameter values, and the first preset condition is determined as a flow determination condition; When the operation stage information indicates that the compressor is in a stable operation stage, the compression ratio and load of the magnetic levitation compressor and the inverter temperature value are determined as target operation parameter values, and the second preset condition is determined as a flow judgment condition. 3. The method according to claim 2, characterized in that, when the operation stage information indicates that the system is in the startup stage, determining whether the operation parameter value satisfies the first preset condition is performed in the following manner: The absolute value of the difference between the temperature of the chilled water and the temperature of the cooling water is greater than or equal to a preset water temperature deviation value; or, The temperature of the chilled water is greater than or equal to a preset water temperature and the temperature of the cooling water is greater than or equal to the preset water temperature. 4. The method according to claim 3, characterized in that, when the operating parameter value meets the first preset condition, performing the flow regulation operation through the flow regulation device comprises: Get the compression ratio; When the compression ratio is less than a preset lower limit compression ratio, controlling the flow regulating device to operate at a maximum flow value until the compression ratio is greater than or equal to the preset lower limit compression ratio; When the compression ratio is greater than or equal to the preset upper limit compression ratio, the pressure value and the inverter temperature value of the magnetic levitation compressor are obtained; and when the pressure value and the inverter temperature value indicate that the preset termination condition is not met, the flow regulating device is controlled to adjust the flow until the preset termination condition is met; The preset termination condition is that the suction pressure value is within the first pressure range, the exhaust pressure value is within the second pressure range, and the inverter temperature value is within the first preset temperature range. 5. The method according to claim 4, characterized in that controlling the flow regulating device to regulate the flow comprises: Obtaining the refrigerant flow rate of the cooling pipeline and the load of the magnetic levitation compressor; When the refrigerant flow rate is within a preset flow rate range and the load is within a preset load range, controlling the flow regulating device to stop regulating the flow rate; When the refrigerant flow rate is outside the preset flow rate range and the load is within the preset load range, the flow regulating device is controlled to fine-tune the flow rate so that the adjusted refrigerant flow rate is within the preset flow rate range. 6. The method according to claim 2, characterized in that, when the operation stage information indicates that the system is in a stable operation stage and the operation parameter value satisfies a second preset condition, performing a flow regulation operation through the flow regulation device comprises: When the load is greater than or equal to the critical load threshold and the compression ratio is outside the first reference range, the flow regulating device is controlled to open; or, When the load is greater than or equal to the critical load threshold and the inverter temperature value is outside the second reference range, the flow regulating device is controlled to be turned on; or, When the load is less than the critical load threshold, the flow regulating device is controlled to open. 7. The method according to claim 6, characterized in that the first reference range and the second reference range are determined in the following manner: Controlling the magnetic suspension chiller to operate at full load; When the system is running at full load and the water temperature is at the set working condition, obtain the current compression ratio and the current inverter temperature value; A compression ratio range corresponding to the current compression ratio is selected as the first reference range, and a second preset temperature range corresponding to the current inverter temperature value is selected as the second reference range. 8. The method according to any one of claims 1 to 7, characterized in that the flow regulating device comprises a variable frequency refrigerant pump, and performing a flow regulating operation by the flow regulating device comprises: performing a flow regulating operation by adjusting a rotation speed value of the variable frequency refrigerant pump; or, The flow regulating device includes a fixed-frequency refrigerant pump and an electronic expansion valve, the fixed-frequency refrigerant pump and the electronic expansion valve are connected in series, and the flow regulating operation is performed by the flow regulating device, including: performing the flow regulating operation by adjusting the opening value of the electronic expansion valve. 9. A control device for a magnetic levitation chiller, comprising a processor and a memory storing program instructions, wherein the processor is configured to execute the control method for a magnetic levitation chiller according to any one of claims 1 to 8 when running the program instructions. 10. A magnetic suspension chiller, comprising: Magnetic levitation compressor; The cooling pipeline is provided with a flow regulating device for regulating the flow of the refrigerant; a condenser connected in series with the cooling pipeline and the magnetic levitation compressor; and The control device for a magnetically suspended chiller as claimed in claim 9 is installed in the cooling pipeline. 11. A storage medium storing program instructions, wherein when the program instructions are run, the control method for a magnetic levitation chiller according to any one of claims 1 to 8 is executed.