CN114508808A - Magnetic suspension variable frequency water chilling unit - Google Patents
Magnetic suspension variable frequency water chilling unit Download PDFInfo
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- CN114508808A CN114508808A CN202210220687.4A CN202210220687A CN114508808A CN 114508808 A CN114508808 A CN 114508808A CN 202210220687 A CN202210220687 A CN 202210220687A CN 114508808 A CN114508808 A CN 114508808A
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F24—HEATING; RANGES; VENTILATING
- F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
- F24F5/00—Air-conditioning systems or apparatus not covered by F24F1/00 or F24F3/00, e.g. using solar heat or combined with household units such as an oven or water heater
- F24F5/0007—Air-conditioning systems or apparatus not covered by F24F1/00 or F24F3/00, e.g. using solar heat or combined with household units such as an oven or water heater cooling apparatus specially adapted for use in air-conditioning
- F24F5/001—Compression cycle type
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B1/00—Compression machines, plants or systems with non-reversible cycle
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
- Y02B30/00—Energy efficient heating, ventilation or air conditioning [HVAC]
- Y02B30/70—Efficient control or regulation technologies, e.g. for control of refrigerant flow, motor or heating
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Abstract
The invention discloses a magnetic suspension variable frequency water chilling unit, which is characterized in that when a load shedding condition is met, the frequency, the pressure ratio and the opening degree of an air suction guide vane of each running compressor are obtained; if both are satisfied: the pressure ratio of each running compressor is within a set pressure ratio range, the opening degree of the air suction guide vane of each running compressor is greater than or equal to a set opening degree threshold value, and the frequency of each running compressor is less than or equal to a set frequency threshold value; shutting down an operating compressor; if not both: the pressure ratio of each running compressor is within a set pressure ratio range, the opening degree of the air suction guide vane of each running compressor is greater than or equal to a set opening degree threshold value, and the frequency of each running compressor is less than or equal to a set frequency threshold value; the frequency of each running compressor is controlled to be reduced or/and the opening degree of the suction guide vane is controlled to be reduced. The magnetic suspension variable frequency water chilling unit not only realizes the energy conservation of the water chilling unit, ensures the reliability of the water chilling unit, improves the energy conservation effect, the reliability and the stability, but also realizes the balance control of the operation efficiency and the energy efficiency of the water chilling unit.
Description
Technical Field
The invention relates to the technical field of air conditioning, in particular to a magnetic suspension variable-frequency water chilling unit.
Background
At present, the research and the application of the frequency conversion magnetic suspension centrifugal water chilling unit are more and more extensive. The variable frequency magnetic suspension centrifugal water chilling unit is mainly characterized by oil-free operation, high efficiency and energy conservation, and is mainly applied to the places of industrial and commercial comfort air conditioners and process air conditioners. Because no mature single compressor with larger cooling capacity exists at present, a mode of connecting a plurality of compressors in parallel is generally adopted to jointly form a single unit in order to meet the requirement of larger cooling capacity. The output refrigerating capacity of the water chilling unit is adjusted by adjusting the running state of each compressor. Because the magnetic suspension centrifugal machine is generally subjected to frequency conversion adjustment, the magnetic suspension centrifugal machine has the advantages of wide operation range, high adjustment speed and the like.
The magnetic suspension centrifugal water chilling unit operates without oil, and can realize efficient operation by using advanced technologies such as direct-drive variable frequency motors and the like. However, since there are multiple compressors operating at the same output capacity, multiple compressors can be operated at a lower part load, or several of the compressors can be stopped, and the remaining compressors can be operated at a higher part load or full load. In short, different control schemes may result in different operating efficiencies, thereby affecting the energy consumption of the user. It becomes necessary to find an efficient control method. How to make the unit operation always in the high-efficient region becomes the problem that faces.
In the existing magnetic suspension variable frequency water chilling unit, the operation of the compressors is generally balanced by monitoring the current, power, load rate and the like of each compressor, and the main purpose is to balance the load rate and the operation time of each compressor, so that the purposes of basically consistent loads and balanced operation time are achieved, and the energy-saving problem of the unit is not considered.
Disclosure of Invention
The invention provides a magnetic suspension variable frequency water chilling unit, which improves the energy-saving effect and the reliability.
In order to achieve the purpose, the invention adopts the following technical scheme:
the invention provides a magnetic suspension variable frequency water chilling unit, which comprises:
the compressor is provided with a plurality of compressors which are connected in parallel;
a controller configured to:
when the load shedding condition is met, acquiring the frequency, the pressure ratio and the opening degree of an air suction guide vane of each running compressor;
judging whether the following conditions are met simultaneously:
the pressure ratio of each running compressor is within a set pressure ratio range;
the condition B is that the opening of the air suction guide vane of each running compressor is more than or equal to a set opening threshold;
the condition C is that the frequency of each running compressor is less than or equal to a set frequency threshold value; obtaining a corresponding set frequency threshold according to a corresponding relation between a preset set frequency threshold and a pressure ratio;
if the conditions A, B and C are met simultaneously, shutting down an operating compressor;
and if the condition A, the condition B and the condition C are not met simultaneously, reducing the frequency of each running compressor or/and reducing the opening of the suction guide vane.
In some embodiments of the present application, the frequency reduction of each running compressor or/and the opening reduction of the suction guide vane specifically include:
judging whether the frequency of each running compressor reaches the minimum frequency and the opening of the suction guide vane reaches the minimum opening or not; wherein the minimum opening is less than a set opening threshold;
if the frequency of each running compressor reaches the minimum frequency and the opening degree of the air suction guide vane reaches the minimum opening degree, one running compressor is shut down;
if the frequency of each running compressor does not meet the requirement that the frequency reaches the minimum frequency and the opening degree of the air suction guide vane reaches the minimum opening degree, judging whether the frequency of each running compressor reaches the minimum frequency or not;
if the frequency of each running compressor does not reach the minimum frequency, reducing the frequency of each running compressor;
and if the frequency of each running compressor reaches the minimum frequency, reducing the opening degree of the suction guide vane of each running compressor.
In some embodiments of the present application, before shutting down an operating compressor, the method further comprises:
acquiring the number of running compressors;
judging whether the number of the running compressors is more than 1;
if the number of the running compressors is more than 1, shutting down one running compressor;
and if the number of the running compressors is less than or equal to 1, the currently running compressors run at the minimum frequency, and the opening degree of the suction guide vane is the minimum opening degree.
In some embodiments of the present application, before shutting down an operating compressor, the method further comprises:
acquiring the number of running compressors;
judging whether the number of the running compressors is more than 1;
if the number of the running compressors is more than 1, shutting down one running compressor;
if the number of the running compressors is less than or equal to 1, judging whether a shutdown condition is met;
if the shutdown condition is met, stopping the magnetic suspension variable frequency water chilling unit;
if the stop condition is not satisfied, the currently operating compressor is operated at the minimum frequency, and the suction guide vane opening degree is the minimum opening degree.
In some embodiments of the present application, condition a specifically is: the pressure ratio for each operating compressor is within the set pressure ratio range for a first set length of time.
In some embodiments of the present application, the controller is further configured to:
and when the conditions A, B and C are simultaneously met and the second setting is continued for a long time, turning off one running compressor.
In some embodiments of the present application, the preset corresponding relationship between the set frequency threshold and the voltage ratio is any one of a relational expression, a relational curve, and a corresponding table.
In some embodiments of the present application, the controller is further configured to:
when the loading condition is met, acquiring the rotating speed of each running compressor;
judging whether the rotating speed of each running compressor is greater than or equal to a set high rotating speed or not;
if the rotating speed of each running compressor is not less than the set high rotating speed, judging whether a non-running compressor exists or not;
if the compressors do not operate, acquiring the pressure ratio of each operating compressor;
judging whether the pressure ratio of each running compressor is less than the lower limit value of the set pressure ratio range or the pressure ratio of each running compressor is greater than the upper limit value of the set pressure ratio range;
and if the pressure ratio of each running compressor is less than the lower limit value of the set pressure ratio range or the pressure ratio of each running compressor is greater than the upper limit value of the set pressure ratio range, starting a stopped compressor.
In some embodiments of the present application, if the pressure ratio of each operating compressor is less than the lower limit value of the set pressure ratio range, or the pressure ratio of each operating compressor is greater than the upper limit value of the set pressure ratio range, starting a stopped compressor, specifically including:
and if the pressure ratio of each running compressor is less than the lower limit value of the set pressure ratio range for a third set time period, or the pressure ratio of each running compressor is greater than the upper limit value of the set pressure ratio range for the third set time period, starting a stopped compressor.
In some embodiments of the present application, the controller is further configured to:
acquiring actual outlet water temperature and target outlet water temperature;
calculating the difference between the actual outlet water temperature and the target outlet water temperature;
judging whether the loading condition or the unloading condition is met:
when the difference value is larger than 0 and the actual outlet water temperature obtained this time is larger than the actual outlet water temperature obtained last time, judging that the loading condition is met;
and when the difference is less than 0 and the actual outlet water temperature obtained this time is less than the actual outlet water temperature obtained last time, judging that the load shedding condition is met.
Compared with the prior art, the technical scheme of the invention has the following technical effects: according to the magnetic suspension variable frequency water chilling unit, when the load shedding condition is met, the frequency, the pressure ratio and the opening degree of the air suction guide vane of each running compressor are obtained; if both: the pressure ratio of each running compressor is within a set pressure ratio range, the opening degree of the air suction guide vane of each running compressor is greater than or equal to a set opening degree threshold value, and the frequency of each running compressor is less than or equal to a set frequency threshold value; shutting down an operating compressor; if not both: the pressure ratio of each running compressor is within a set pressure ratio range, the opening degree of the air suction guide vane of each running compressor is greater than or equal to a set opening degree threshold value, and the frequency of each running compressor is less than or equal to a set frequency threshold value; the frequency of each running compressor is controlled to be reduced or/and the opening degree of the suction guide vane is controlled to be reduced. Therefore, the magnetic suspension variable frequency water chilling unit not only realizes the energy conservation of the magnetic suspension variable frequency water chilling unit, ensures the reliability of the magnetic suspension variable frequency water chilling unit, improves the energy conservation effect, the reliability and the stability, but also realizes the balance control of the operation efficiency and the energy efficiency of the magnetic suspension variable frequency water chilling unit.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.
FIG. 1 is a schematic structural diagram of one embodiment of a magnetic suspension variable frequency water chilling unit;
FIG. 2 is an electrical control block diagram of one embodiment of the magnetic suspension variable frequency water chilling unit of the present invention;
FIG. 3 is a flow chart of one embodiment of a control method executed by a controller of the magnetic levitation variable frequency water chilling unit according to the present invention;
FIG. 4 is a relationship curve of a set frequency threshold value and a pressure ratio of the magnetic suspension variable frequency water chilling unit;
FIG. 5 is a flow chart of another embodiment of a control method executed by a controller of the magnetic levitation variable frequency water chilling unit according to the present invention;
FIG. 6 is a flow chart of a control method executed by a controller of the magnetic levitation variable frequency water chilling unit according to another embodiment of the present invention;
FIG. 7 is a flow chart of a control method executed by a controller of the magnetic levitation variable frequency water chilling unit according to another embodiment of the present invention;
FIG. 8 is a flow chart of a control method executed by a controller of the magnetic levitation variable frequency water chilling unit according to another embodiment of the present invention;
FIG. 9 is a flow chart of a control method executed by a controller of the magnetic levitation variable frequency water chilling unit according to another embodiment of the present invention;
fig. 10 is a flowchart of a control method executed by a controller of a magnetic suspension variable frequency water chilling unit according to another embodiment of the present invention.
Reference numerals:
1. a condenser; 2. a throttle valve; 3. an evaporator.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.
In the description of the present application, it is to be understood that the terms "center," "upper," "lower," "front," "back," "top," "bottom," "inner," "outer," and the like are used in the orientations and positional relationships indicated in the drawings for convenience in describing the present application and for simplicity in description, and do not indicate or imply that the referenced devices or elements must have a particular orientation, be constructed in a particular orientation, and be operated in a particular manner, and are not to be construed as limiting the present application.
In the description of the present application, it is to be understood that the terms "first", "second" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implying any number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present application, "a plurality" means two or more unless otherwise specified.
In the description of the present application, it should be noted that, unless otherwise explicitly stated or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be, for example, a fixed connection, a detachable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present application can be understood in a specific case by those of ordinary skill in the art.
The chiller includes a compressor, a condenser 1, a throttle valve 2, and an evaporator 3, as shown in fig. 1. The compressor, the condenser 1, the throttle valve 2 and the evaporator 3 are communicated in sequence to form a refrigerant circulation pipeline. It should be noted that, in the embodiment of the present invention, the sequential connection only illustrates a sequential relationship of connection between the respective devices, and other devices, such as a stop valve, may also be included between the respective devices.
During refrigeration, the compressor compresses low-temperature and low-pressure refrigerant gas into high-temperature and high-pressure refrigerant gas which is discharged to the condenser 1, the high-temperature and high-pressure refrigerant gas exchanges heat with cooling water in the condenser 1, the refrigerant releases heat, the released heat is brought into outdoor environment air by the cooling water, and the refrigerant is subjected to phase change and is condensed into liquid or gas-liquid two-phase refrigerant. The refrigerant flows out of the condenser 1 and enters the throttle valve 2 to be cooled and decompressed into a low-temperature and low-pressure refrigerant. The low-temperature and low-pressure refrigerant enters the evaporator 3, and the refrigerant absorbs the heat of the chilled water in the evaporator 3, so that the temperature of the chilled water in the evaporator 3 is reduced, and the refrigeration effect is realized. The refrigerant is phase-changed and evaporated into low-temperature and low-pressure refrigerant gas, and the refrigerant gas flows back into the compressor, so that the recycling of the refrigerant is realized.
The evaporator 3 of the present embodiment is also connected to the user side, and the chilled water in the evaporator 3 enters the user side after the temperature of the chilled water is lowered, and the chilled water in the evaporator 3 can be replenished from the user side.
Wherein the throttle valve 2 may be an electronic expansion valve.
The magnetic suspension variable frequency water chilling unit further comprises a controller, and the controller controls the operation of the whole magnetic suspension variable frequency water chilling unit.
In the magnetic suspension variable frequency water chilling unit of the embodiment, a plurality of compressors are arranged and are connected in parallel. The compressor may be a magnetically levitated variable frequency centrifugal compressor.
For example, the magnetic suspension variable frequency water chilling unit comprises N compressors, namely a compressor 1#, a compressor 2#, an … … and a compressor N #, wherein the N compressors are connected in parallel.
The suction port of each compressor is provided with a suction pressure sensor and a suction temperature sensor, which are respectively used for detecting suction pressure and suction temperature and sending the detected suction pressure and suction temperature to the controller, as shown in fig. 2.
And the exhaust port of each compressor is provided with an exhaust pressure sensor and an exhaust temperature sensor which are respectively used for detecting exhaust pressure and exhaust temperature and sending the detected exhaust pressure and exhaust temperature to the controller.
The pressure ratio per compressor = discharge pressure/suction pressure.
Each compressor is provided with an air suction guide vane (IGV), and the controller controls the opening degree of the air suction guide vane of each compressor.
The condenser 1 is provided with a condensing pressure sensor for detecting condensing pressure and sending the detected condensing pressure to the controller.
The evaporator 3 is provided with an evaporation pressure sensor for detecting the evaporation pressure and sending the detected evaporation pressure to the controller.
In the magnetic levitation variable frequency water chilling unit of the present embodiment, the controller is configured to:
when the load shedding condition is met, acquiring the frequency, the pressure ratio and the opening degree of an air suction guide vane of each running compressor;
judging whether the following conditions are met simultaneously:
the pressure ratio of each running compressor is within a set pressure ratio range;
the condition B is that the opening of the air suction guide vane of each running compressor is more than or equal to a set opening threshold;
the condition C is that the frequency of each running compressor is less than or equal to a set frequency threshold value; obtaining a corresponding set frequency threshold according to a corresponding relation between a preset set frequency threshold and a pressure ratio;
if the conditions A, B and C are met simultaneously, shutting down an operating compressor;
and if the condition A, the condition B and the condition C are not met simultaneously, reducing the frequency of each running compressor or/and reducing the opening of the suction guide vane.
Specifically, the controller is configured to perform the following steps, as shown in fig. 3.
Step S11: and when the load shedding condition is met, acquiring the frequency, the pressure ratio and the opening degree of the suction guide vane of each running compressor.
Step S12: judging whether the following conditions are met simultaneously:
condition a. the pressure ratio of each operating compressor is within the set pressure ratio range.
And B, the opening degree of the suction guide vane of each running compressor is larger than or equal to a set opening degree threshold value.
The condition C is that the frequency of each running compressor is less than or equal to a set frequency threshold value; and obtaining a corresponding set frequency threshold according to the corresponding relation between the preset set frequency threshold and the pressure ratio. According to the pressure ratio obtained in step S11 and the corresponding relationship, a corresponding set frequency threshold is obtained.
If the conditions A, B and C are simultaneously met, the operation of one compressor is turned off, and the energy is saved compared with the condition that a plurality of compressors simultaneously reduce the opening degree of the air suction guide vane or reduce the frequency, so the operation state can be called as the head reduction energy-saving operation state; step S13 is executed: one running compressor is shut down.
If the condition A, the condition B and the condition C are not met simultaneously, the condition means that the opening degree of the suction guide vane of each compressor is reduced or the frequency is reduced to save more energy, and the condition can be called as the same load reduction energy-saving operation state; step S14 is executed: and controlling each running compressor to reduce frequency or/and the opening degree of the suction guide vane to reduce.
According to the magnetic suspension variable frequency water chilling unit, when the load shedding condition is met, the frequency, the pressure ratio and the opening degree of the air suction guide vane of each running compressor are obtained through design; if both: the pressure ratio of each running compressor is within a set pressure ratio range, the opening degree of the air suction guide vane of each running compressor is greater than or equal to a set opening degree threshold value, and the frequency of each running compressor is less than or equal to a set frequency threshold value; shutting down an operating compressor; if not both: the pressure ratio of each running compressor is within a set pressure ratio range, the opening degree of the air suction guide vane of each running compressor is greater than or equal to a set opening degree threshold value, and the frequency of each running compressor is less than or equal to a set frequency threshold value; controlling each running compressor to reduce the frequency or/and the opening degree of the suction guide vane to be reduced; therefore, the magnetic suspension variable frequency water chilling unit of the embodiment not only realizes energy conservation of the magnetic suspension variable frequency water chilling unit, ensures the reliability of the magnetic suspension variable frequency water chilling unit, improves the energy-saving effect, the reliability and the stability, but also realizes the balance control of the operating efficiency and the energy efficiency of the magnetic suspension variable frequency water chilling unit.
In some embodiments of the present application, each compressor of the magnetic levitation variable frequency chiller has equal capacity. And when each running compressor is controlled to reduce the frequency, each running compressor is controlled to reduce the frequency at the same time, and the same frequency value is reduced. When each running compressor is controlled to reduce the opening degree of the air suction guide vane, the opening degree of the air suction guide vane of each running compressor is reduced simultaneously, and the same opening degree value is reduced.
In some embodiments of this application, in order to improve the accuracy that the compressor opens and stops the judgement, prevent frequently to open and stop the compressor, guarantee magnetic suspension frequency conversion cooling water set's stability and reliability, condition A is: the pressure ratio for each operating compressor is within the set pressure ratio range for a first set length of time. Therefore, the condition a is satisfied only if the pressure of each of the operating compressors is longer than when the first setting continues within the set pressure ratio range.
In some embodiments of the present application, the first set time period is 60 seconds.
In some embodiments of the application, in order to improve the accuracy of the start-stop judgment of the compressor, prevent the frequent start-stop of the compressor, ensure the stability and reliability of the magnetic suspension variable frequency water chilling unit, and when the conditions A, B and C are simultaneously met and the second setting is continued for a long time, the running compressor is shut down.
In some embodiments of the present application, the second set period of time is 10 minutes.
In some embodiments of the present application, the preset corresponding relationship between the set frequency threshold and the pressure ratio is any one of a relational expression, a relational curve, and a corresponding table.
In some embodiments of the present application, the preset corresponding relationship between the set frequency threshold and the pressure ratio is a relational expression. For example, the following relationship:
y=343.8x4-3501.8x3+13334x2-22477x+14348；
wherein y is a set frequency threshold; and x is a pressure ratio.
Therefore, for each compressor in operation, the corresponding set frequency threshold can be calculated by substituting the pressure ratio into the above-described relational expression.
That is, in some embodiments of the present application, condition C is:
the frequency of each running compressor is less than or equal to 343.8x4-3501.8x3+13334x2-22477x+14348。
And the relation between the set frequency threshold and the pressure ratio is stored in a memory of the magnetic suspension variable frequency water chilling unit. When the set frequency threshold needs to be obtained, the pressure ratio of the compressor is substituted into the relational expression, and the corresponding set frequency threshold can be simply, conveniently, quickly and accurately obtained.
In still other embodiments of the present application, the preset corresponding relationship between the set frequency threshold and the pressure ratio may also be a relationship curve. As shown in fig. 4, the mathematical expression of the relationship curve is the above relationship.
And a relation curve of the set frequency threshold value and the pressure ratio is stored in a memory of the magnetic suspension variable frequency water chilling unit. When the set frequency threshold needs to be obtained, the corresponding set frequency threshold is obtained according to the relation curve, and the method is simple, convenient, rapid and accurate.
In still other embodiments of the present application, the preset corresponding relationship between the set frequency threshold and the pressure ratio may also be a corresponding table.
And a corresponding table for setting the frequency threshold value and the pressure ratio is stored in a memory of the magnetic suspension variable frequency water chilling unit. When the set frequency threshold needs to be obtained, the corresponding table is directly inquired, and the set frequency threshold corresponding to the pressure ratio is simply, conveniently, quickly and accurately obtained.
According to the data in the corresponding table, the relation curve can be fitted.
In some embodiments of the present application, the set pressure ratio range is 2.3-2.85, the lower limit value of the set pressure ratio range is 2.3, and the upper limit value is 2.85. The opening degree threshold is set to 99% of the full opening degree of the suction guide vane.
In step S14, each running compressor is down-converted or/and the suction guide vane opening is decreased, which includes the following steps, as shown in fig. 5.
Step S14-1: judging whether the frequency of each running compressor reaches the minimum frequency and the opening of the suction guide vane reaches the minimum opening or not; wherein the minimum opening is less than a set opening threshold. The minimum frequency is the minimum frequency at which the compressor can operate.
If the frequency of each running compressor reaches the minimum frequency and the opening degree of the suction guide vane reaches the minimum opening degree, executing the step S14-2: an operating compressor is shut down.
And if the frequency of each running compressor is not met and the opening degree of the suction guide vane reaches the minimum opening degree, executing the step S14-3.
Step S14-3: and judging whether the frequency of each running compressor reaches the minimum frequency or not.
If the frequency of each running compressor does not reach the minimum frequency, the step S14-4 is executed: reducing the frequency of each running compressor;
if the frequency of each operating compressor reaches the minimum frequency, the step S14-5 is performed: the opening of the suction guide vane of each running compressor is reduced.
Therefore, whether the frequency of the compressor is the minimum frequency and the opening degree of the air suction guide vane is the minimum opening degree is judged, and if the frequency of the compressor is the minimum frequency and the opening degree of the air suction guide vane is the minimum opening degree, one running compressor is shut down; if not, judging whether the frequency of the compressor reaches the minimum frequency, and if not, controlling the compressor to reduce the frequency; if the minimum frequency is reached, the compressor suction guide vane opening is reduced.
That is, first consider reducing the compressor frequency, and when the compressor frequency has been reduced to the minimum frequency, then reduce the suction guide vane opening; if the suction guide vane opening is also reduced to the minimum opening, an operating compressor is shut down.
Through the design steps of S14-1-S14-5, the magnetic suspension variable frequency water chilling unit is ensured to operate stably, and the phenomenon that the magnetic suspension variable frequency water chilling unit is unstable due to the fact that the compressor is adjusted too fast is avoided.
In some embodiments of the present application, the following steps are included prior to shutting down an operating compressor, as shown in fig. 6.
Step S21: the number of operating compressors is obtained.
Step S22: judging whether the number of the running compressors is more than 1;
if the number of running compressors is greater than 1, one running compressor is shut down.
If the number of the operating compressors is less than or equal to 1, executing step S23: the currently operating compressor is operated at the minimum frequency and the suction guide vane opening is the minimum opening.
Through the design steps S21-S23, when the number of the running compressors is more than 1, one running compressor can be directly shut down; when the number of the operating compressors is less than or equal to 1, which indicates that only one compressor operates at present, the operating compressor is controlled to operate at the minimum frequency and the air suction guide vane operates at the minimum opening degree, so that the integral shutdown of the magnetic suspension variable frequency water chilling unit caused by shutdown of the compressor is avoided, and the operation of the magnetic suspension variable frequency water chilling unit is ensured.
In still other embodiments of the present application, the following steps are included prior to shutting down an operating compressor, as shown in FIG. 7.
Step S31: the number of operating compressors is obtained.
Step S32: it is determined whether the number of operating compressors is > 1.
If the number of running compressors is greater than 1, one running compressor is shut down.
If the number of operating compressors is less than or equal to 1, step S33 is performed.
Step S33: and judging whether the shutdown condition is met.
If the stop condition is satisfied, step S34 is executed: and stopping the magnetic suspension variable frequency water chilling unit.
If the stop condition is not satisfied, step S35 is executed: the currently operating compressor is operated at the minimum frequency and the suction guide vane opening is the minimum opening.
The shutdown condition is that the difference value between the actual effluent temperature and the target effluent temperature is less than the shutdown threshold value. The shutdown threshold is < 0. For example a shutdown threshold = -5 ℃. Namely, when the difference between the actual water outlet temperature and the target water outlet temperature is less than-5 ℃, the magnetic suspension variable frequency water chilling unit reaches the control target, and the magnetic suspension variable frequency water chilling unit stops to achieve the energy-saving purpose.
Through the design steps S31-S35, when the number of the running compressors is more than 1, one running compressor can be directly shut down; when the number of the operating compressors is less than or equal to 1, the fact that only one compressor operates at present is indicated, whether a shutdown condition is met is judged, and if the shutdown condition is met, the magnetic suspension variable frequency water chilling unit is stopped; if the shutdown condition is not met, the running compressor is controlled to run at the minimum frequency and the air suction guide vane runs at the minimum opening degree, the integral shutdown of the magnetic suspension variable frequency water chilling unit caused by shutdown of the compressor is avoided, and the running of the magnetic suspension variable frequency water chilling unit is guaranteed.
In some embodiments of the present application, shutting down an operating compressor specifically includes: and in all running compressors, shutting down one compressor with the longest accumulated running time so as to balance the running time of all the compressors in the magnetic suspension variable frequency water chilling unit and prolong the service life of the compressors and the whole service life of the magnetic suspension variable frequency water chilling unit.
In other embodiments of the present application, the controller of the magnetically levitated variable frequency chiller is further configured to perform the following steps, as illustrated with reference to fig. 8.
Step S41: and when the loading condition is met, acquiring the rotating speed of each running compressor.
Step S42: and judging whether the rotating speed of each running compressor is greater than or equal to a set high rotating speed.
In this embodiment, the high rotation speed is set to 95% of the maximum rotation speed of the compressor.
And if the rotating speed of each running compressor is not equal to or larger than the set high rotating speed, judging whether the loading condition is met again, and if the loading condition is met, executing the step S41.
If the rotating speed of each running compressor is not less than the set high rotating speed, executing the step S43: and judging whether a compressor which is not operated exists.
If all the compressors have been operated, it is redetermined whether the loading condition is satisfied, and when the loading condition is satisfied, step S41 is performed.
If there are more compressors not operating, step S44 is executed: the pressure ratio of each operating compressor is obtained.
Step S45: and judging whether the pressure ratio of each running compressor is less than the lower limit value of the set pressure ratio range or the pressure ratio of each running compressor is greater than the upper limit value of the set pressure ratio range.
If not, it is redetermined whether the loading condition is satisfied, and when the loading condition is satisfied, step S41 is executed.
If the pressure ratio of each operating compressor is less than the lower limit value of the set pressure ratio range, or the pressure ratio of each operating compressor is greater than the upper limit value of the set pressure ratio range, executing step S46: a stopped compressor is started.
Through the design steps S41-S46, when the loading condition is met, the rotating speed of each running compressor is not less than or equal to the set high rotating speed, and the compressors do not run, and the pressure ratio of each running compressor is less than the lower limit value of the set pressure ratio range or is more than the upper limit value of the set pressure ratio range, a stopped compressor is started, the loading requirement of the magnetic suspension variable frequency water chilling unit is met, and the phenomenon that the stability of the magnetic suspension variable frequency water chilling unit is influenced by frequent starting and stopping of the compressors is avoided.
In some embodiments of the present application, if the pressure ratio of each operating compressor is less than the lower limit value of the set pressure ratio range, or the pressure ratio of each operating compressor is greater than the upper limit value of the set pressure ratio range, starting a stopped compressor, specifically including:
and if the pressure ratio of each running compressor is less than the lower limit value of the set pressure ratio range for a third set time period, or the pressure ratio of each running compressor is greater than the upper limit value of the set pressure ratio range for the third set time period, starting a stopped compressor.
Through increasing the restriction of lasting the third setting duration, the accuracy of the compressor start-stop judgment is improved, the compressor is prevented from being frequently started and stopped, and the stability of the magnetic suspension variable frequency water chilling unit is ensured.
In some embodiments of the present application, the third set time period is 60 seconds.
In some embodiments of the present application, starting a shutdown compressor specifically includes: and starting one compressor with the shortest accumulated running time in all shutdown compressors to balance the running time of all the compressors in the magnetic suspension variable frequency water chilling unit and prolong the service life of the compressors and the whole service life of the magnetic suspension variable frequency water chilling unit.
In some embodiments of the present application, the controller is further configured to perform the following steps, as illustrated with reference to fig. 9.
Step S51: and acquiring the actual water outlet temperature and the target water outlet temperature of the magnetic suspension variable-frequency water chilling unit.
Step S52: and calculating the difference value between the actual outlet water temperature and the target outlet water temperature.
Step S53: and judging whether the loading condition or the unloading condition is met.
When the difference value is larger than 0 and the actual outlet water temperature obtained this time is larger than the actual outlet water temperature obtained last time, judging that the loading condition is met;
and when the difference is less than 0 and the actual outlet water temperature obtained this time is less than the actual outlet water temperature obtained last time, judging that the load shedding condition is met.
And under other conditions, the magnetic suspension variable frequency water chilling unit keeps the current running state.
Therefore, when the difference value is larger than 0 and the actual outlet water temperature has an increasing trend, the loading condition is judged to be met;
when the difference is less than 0 and the actual outlet water temperature has a decreasing trend, judging that the load shedding condition is met;
and under other conditions, judging that the magnetic suspension variable frequency water chilling unit keeps the current running state.
According to the difference value between the actual outlet water temperature and the target outlet water temperature and the variation trend of the actual outlet water temperature, whether the loading condition or the unloading condition is met can be accurately judged, and the method is simple and convenient to implement.
In some embodiments of the present application, a PID logic determination control module is provided in the controller to determine loading or unloading according to water temperature and PID control (proportional integral derivative). Assuming that the target outlet water temperature is 7 ℃, if the current actual outlet water temperature is 9 ℃ and the current actual outlet water temperature has a trend of continuously rising, the PID gives a judgment that loading is required; if the current actual outlet water temperature is 6 ℃ and the trend of continuous decline exists (but the shutdown condition is not met), the PID judges that the load is required to be reduced.
Next, the steps of loading and unloading the magnetic suspension variable frequency water chilling unit will be described in detail by using an embodiment, and refer to fig. 10.
In the running process of the unit, whether the load shedding condition or the load shedding condition is met is judged firstly.
And when the difference value is larger than 0 and the actual outlet water temperature obtained this time is larger than the actual outlet water temperature obtained last time, judging that the loading condition is met.
And when the difference is less than 0 and the actual outlet water temperature obtained this time is less than the actual outlet water temperature obtained last time, judging that the load shedding condition is met.
And under other conditions, the magnetic suspension variable frequency water chilling unit keeps the current running state.
(1) When the load shedding condition is satisfied, it is determined whether or not the condition A, B, C is satisfied:
and under the condition A, the pressure ratio of each running compressor lasts for 60 seconds within 2.3-2.85.
And B, the opening degree of the suction guide vane of each running compressor is more than or equal to 99 percent of the full opening degree.
And C, the frequency of each running compressor is less than or equal to a set frequency threshold value.
Setting the relation between the frequency threshold and the pressure ratio as follows:
y=343.8x4-3501.8x3+13334x2-22477x+14348；
wherein y is a set frequency threshold; and x is a pressure ratio.
If the condition A, B, C is met, judging whether the current state is kept for 10 minutes, if so, shutting down a compressor with the longest accumulated running time; if not, whether the load shedding condition or the load shedding condition is met is judged again.
If condition A, B, C is not satisfied at the same time, each operating compressor is controlled to simultaneously reduce the frequency and reduce the suction guide vane opening. And then judging whether the compressor reaches the minimum frequency (or the minimum rotating speed), and if the frequency (or the minimum rotating speed) of each running compressor is not reduced to the minimum frequency (or the minimum rotating speed), judging whether the load shedding condition or the load shedding condition is met again.
If each running compressor is reduced to the minimum frequency (or the minimum rotating speed), judging whether the number of the running compressors is more than 1; if the running time is more than 1, the compressor with the longest accumulated running time is shut down. And if the load shedding condition is not greater than 1, judging whether the load shedding condition or the load shedding condition is met again.
(2) And when the loading condition is met, judging whether the rotating speed of each running compressor is more than or equal to 95% of the maximum rotating speed.
If not, whether the load shedding condition or the load shedding condition is met is judged again.
If yes, judging whether the compressor does not operate.
And if no compressor is not operated, judging whether the load shedding condition or the load shedding condition is met again.
If the compressors are not operated, judging whether the pressure ratio of each operated compressor is less than 2.3 for 60 seconds or the pressure ratio of each operated compressor is more than 2.85 for 60 seconds.
If not, whether the load shedding condition or the load shedding condition is met is judged again.
If so, starting a compressor with the longest shutdown time.
(3) And when the magnetic suspension variable-frequency water chilling unit is judged to be kept in the current running state, keeping the current state of each compressor.
For the magnetic suspension variable frequency water chilling unit with multiple machine heads, the logic of fig. 10 should be followed when loading, unloading and maintaining are carried out to achieve efficiency balance.
The energy efficiency of the operation of the magnetic suspension variable frequency water chilling unit is related to parameters such as pressure ratio, compressor frequency, opening degree of an air suction guide vane, actual outlet water temperature, target outlet water temperature, actual outlet water temperature change trend and the like. The magnetic suspension variable frequency water chilling unit of the embodiment can better solve the problem of efficiency balance (namely the associated problem of balance of operation efficiency and energy efficiency of the magnetic suspension variable frequency water chilling unit with a plurality of compressors and unit operation time) by optimizing the control logic among the pressure ratio, the compressor frequency, the opening degree of the air suction guide vane, the actual water outlet temperature, the target water outlet temperature and the actual water outlet temperature change trend
The magnetic suspension variable frequency water chilling unit realizes efficiency balance, optimizes the operation energy consumption condition, achieves the purposes of energy conservation and consumption reduction, and improves the reliability and stability of the unit.
In the foregoing description of embodiments, the particular features, structures, materials, or characteristics may be combined in any suitable manner in any one or more embodiments or examples. The above description is only for the specific embodiments of the present invention, but the scope of the present invention is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present invention are included in the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.
Claims (10)
1. A magnetic suspension variable frequency water chilling unit is characterized by comprising:
the compressor is provided with a plurality of compressors which are connected in parallel;
a controller configured to:
when the load shedding condition is met, acquiring the frequency, the pressure ratio and the opening degree of an air suction guide vane of each running compressor;
judging whether the following conditions are met simultaneously:
the pressure ratio of each running compressor is within a set pressure ratio range;
the condition B is that the opening of the air suction guide vane of each running compressor is more than or equal to a set opening threshold;
the condition C is that the frequency of each running compressor is less than or equal to a set frequency threshold value; obtaining a corresponding set frequency threshold according to a corresponding relation between a preset set frequency threshold and a pressure ratio;
if the conditions A, B and C are met simultaneously, shutting down an operating compressor;
and if the condition A, the condition B and the condition C are not met simultaneously, reducing the frequency of each running compressor or/and reducing the opening of the suction guide vane.
2. The magnetic suspension variable frequency water chilling unit of claim 1, characterized in that: each running compressor reduces the frequency or/and reduces the opening degree of an air suction guide vane, and the method specifically comprises the following steps:
judging whether the frequency of each running compressor reaches the minimum frequency and the opening of the suction guide vane reaches the minimum opening or not; wherein the minimum opening is less than a set opening threshold;
if the frequency of each running compressor reaches the minimum frequency and the opening degree of the air suction guide vane reaches the minimum opening degree, one running compressor is shut down;
if the frequency of each running compressor does not meet the requirement that the frequency reaches the minimum frequency and the opening degree of the air suction guide vane reaches the minimum opening degree, judging whether the frequency of each running compressor reaches the minimum frequency or not;
if the frequency of each running compressor does not reach the minimum frequency, reducing the frequency of each running compressor;
and if the frequency of each running compressor reaches the minimum frequency, reducing the opening degree of the suction guide vane of each running compressor.
3. The magnetic suspension variable frequency water chilling unit of claim 1, characterized in that: before the shutdown of an operating compressor, the method further comprises:
acquiring the number of running compressors;
judging whether the number of the running compressors is more than 1;
if the number of the running compressors is more than 1, shutting down one running compressor;
and if the number of the running compressors is less than or equal to 1, the currently running compressors run at the minimum frequency, and the opening degree of the suction guide vane is the minimum opening degree.
4. The magnetic suspension variable frequency water chilling unit of claim 1, characterized in that: before the shutdown of an operating compressor, the method further comprises:
acquiring the number of running compressors;
judging whether the number of the running compressors is more than 1;
if the number of the running compressors is more than 1, shutting down one running compressor;
if the number of the running compressors is less than or equal to 1, judging whether a shutdown condition is met;
if the shutdown condition is met, stopping the magnetic suspension variable frequency water chilling unit;
if the stop condition is not satisfied, the currently operating compressor is operated at the minimum frequency, and the suction guide vane opening degree is the minimum opening degree.
5. The magnetic suspension variable frequency water chilling unit of claim 1, characterized in that: the condition A is specifically as follows: the pressure ratio for each operating compressor is within the set pressure ratio range for a first set length of time.
6. The magnetic suspension variable frequency water chilling unit of claim 1, characterized in that: the controller is further configured to:
and when the conditions A, B and C are simultaneously met and the second setting is continued for a long time, one running compressor is shut down.
7. The magnetic suspension variable frequency water chilling unit of claim 1, characterized in that: the preset corresponding relation between the set frequency threshold and the pressure ratio is any one of a relational expression, a relational curve and a corresponding table.
8. The magnetic suspension variable frequency water chilling unit of claim 1, characterized in that: the controller is further configured to:
when the loading condition is met, acquiring the rotating speed of each running compressor;
judging whether the rotating speed of each running compressor is greater than or equal to a set high rotating speed or not;
if the rotating speed of each running compressor is not less than the set high rotating speed, judging whether a non-running compressor exists or not;
if the compressors do not operate, acquiring the pressure ratio of each operating compressor;
judging whether the pressure ratio of each running compressor is less than the lower limit value of the set pressure ratio range or the pressure ratio of each running compressor is greater than the upper limit value of the set pressure ratio range;
and if the pressure ratio of each running compressor is less than the lower limit value of the set pressure ratio range or the pressure ratio of each running compressor is greater than the upper limit value of the set pressure ratio range, starting a stopped compressor.
9. The magnetic suspension variable frequency water chilling unit of claim 8, wherein: if the pressure ratio of each running compressor is less than the lower limit value of the set pressure ratio range or the pressure ratio of each running compressor is greater than the upper limit value of the set pressure ratio range, starting a stopped compressor, specifically comprising the following steps:
and if the pressure ratio of each running compressor is less than the lower limit value of the set pressure ratio range for a third set time period, or the pressure ratio of each running compressor is greater than the upper limit value of the set pressure ratio range for the third set time period, starting a stopped compressor.
10. The magnetic levitation variable frequency water chilling unit according to any one of claims 1 to 9, wherein: the controller is further configured to:
acquiring actual outlet water temperature and target outlet water temperature;
calculating the difference between the actual outlet water temperature and the target outlet water temperature;
judging whether the loading condition or the unloading condition is met:
when the difference value is larger than 0 and the actual outlet water temperature obtained this time is larger than the actual outlet water temperature obtained last time, judging that the loading condition is met;
and when the difference is less than 0 and the actual outlet water temperature obtained this time is less than the actual outlet water temperature obtained last time, judging that the load shedding condition is met.
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Citations (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2001153475A (en) * | 1999-11-25 | 2001-06-08 | Hitachi Ltd | Refrigerating plant |
| JP2008039201A (en) * | 2006-08-01 | 2008-02-21 | Sanyo Electric Co Ltd | Refrigerating device |
| JP2008309482A (en) * | 2008-09-29 | 2008-12-25 | Sanyo Electric Co Ltd | Refrigerating unit |
| JP2012117698A (en) * | 2010-11-29 | 2012-06-21 | Ebara Refrigeration Equipment & Systems Co Ltd | Turbo refrigerating machine system |
| US20170009775A1 (en) * | 2015-07-06 | 2017-01-12 | Johnson Controls Technology Company | Capacity control system and method for multi-stage centrifugal compressor |
| CN107036351A (en) * | 2017-04-28 | 2017-08-11 | 依米康冷元节能科技（上海）有限公司 | The control method and device of multi-machine heads handpiece Water Chilling Units |
| CN206695418U (en) * | 2016-12-27 | 2017-12-01 | 浙江青风环境股份有限公司 | Magnetic suspension handpiece Water Chilling Units |
| WO2018016028A1 (en) * | 2016-07-20 | 2018-01-25 | 三菱電機株式会社 | Refrigeration cycle device |
| WO2018079731A1 (en) * | 2016-10-28 | 2018-05-03 | ダイキン工業株式会社 | Refrigeration device |
| CN108344115A (en) * | 2018-02-07 | 2018-07-31 | 广东美的暖通设备有限公司 | Control method, air-cooled unit and the storage medium of air-cooled unit |
| CN110906477A (en) * | 2019-11-07 | 2020-03-24 | 广东申菱环境***股份有限公司 | Efficient and stable magnetic suspension water chilling unit, control method and device |
| CN113654255A (en) * | 2021-08-02 | 2021-11-16 | 北京京仪自动化装备技术股份有限公司 | Refrigeration system, compressor frequency control method, electronic device, and storage medium |
| WO2021233476A1 (en) * | 2020-11-25 | 2021-11-25 | 青岛海尔空调电子有限公司 | Water chilling unit and control method therefor, and storage medium and control apparatus |
| CN113790484A (en) * | 2021-07-29 | 2021-12-14 | 依米康科技集团股份有限公司 | Double-frequency-conversion machine room air conditioning unit with air supply control function and control method thereof |
-
2022
- 2022-03-08 CN CN202210220687.4A patent/CN114508808B/en active Active
Patent Citations (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2001153475A (en) * | 1999-11-25 | 2001-06-08 | Hitachi Ltd | Refrigerating plant |
| JP2008039201A (en) * | 2006-08-01 | 2008-02-21 | Sanyo Electric Co Ltd | Refrigerating device |
| JP2008309482A (en) * | 2008-09-29 | 2008-12-25 | Sanyo Electric Co Ltd | Refrigerating unit |
| JP2012117698A (en) * | 2010-11-29 | 2012-06-21 | Ebara Refrigeration Equipment & Systems Co Ltd | Turbo refrigerating machine system |
| US20170009775A1 (en) * | 2015-07-06 | 2017-01-12 | Johnson Controls Technology Company | Capacity control system and method for multi-stage centrifugal compressor |
| WO2018016028A1 (en) * | 2016-07-20 | 2018-01-25 | 三菱電機株式会社 | Refrigeration cycle device |
| WO2018079731A1 (en) * | 2016-10-28 | 2018-05-03 | ダイキン工業株式会社 | Refrigeration device |
| CN206695418U (en) * | 2016-12-27 | 2017-12-01 | 浙江青风环境股份有限公司 | Magnetic suspension handpiece Water Chilling Units |
| CN107036351A (en) * | 2017-04-28 | 2017-08-11 | 依米康冷元节能科技（上海）有限公司 | The control method and device of multi-machine heads handpiece Water Chilling Units |
| CN108344115A (en) * | 2018-02-07 | 2018-07-31 | 广东美的暖通设备有限公司 | Control method, air-cooled unit and the storage medium of air-cooled unit |
| CN110906477A (en) * | 2019-11-07 | 2020-03-24 | 广东申菱环境***股份有限公司 | Efficient and stable magnetic suspension water chilling unit, control method and device |
| WO2021233476A1 (en) * | 2020-11-25 | 2021-11-25 | 青岛海尔空调电子有限公司 | Water chilling unit and control method therefor, and storage medium and control apparatus |
| CN113790484A (en) * | 2021-07-29 | 2021-12-14 | 依米康科技集团股份有限公司 | Double-frequency-conversion machine room air conditioning unit with air supply control function and control method thereof |
| CN113654255A (en) * | 2021-08-02 | 2021-11-16 | 北京京仪自动化装备技术股份有限公司 | Refrigeration system, compressor frequency control method, electronic device, and storage medium |
Non-Patent Citations (1)
| Title |
|---|
| 邓杰文;钱漾漾;魏庆?;张辉;: "磁悬浮变频冷水机组运行特性分析及控制策略研究", 暖通空调, no. 03, pages 25 - 29 * |
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