CN117450623A - Compressor frequency control method and air conditioning unit - Google Patents
Compressor frequency control method and air conditioning unit Download PDFInfo
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- CN117450623A CN117450623A CN202311775179.3A CN202311775179A CN117450623A CN 117450623 A CN117450623 A CN 117450623A CN 202311775179 A CN202311775179 A CN 202311775179A CN 117450623 A CN117450623 A CN 117450623A
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- 238000004378 air conditioning Methods 0.000 title claims abstract description 48
- 238000000034 method Methods 0.000 title claims abstract description 41
- 230000008859 change Effects 0.000 claims abstract description 80
- 239000003507 refrigerant Substances 0.000 claims description 18
- 230000003247 decreasing effect Effects 0.000 claims description 13
- 238000001514 detection method Methods 0.000 claims description 9
- 238000010438 heat treatment Methods 0.000 claims description 7
- 238000005057 refrigeration Methods 0.000 claims description 3
- 238000001816 cooling Methods 0.000 description 15
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 7
- 230000001276 controlling effect Effects 0.000 description 5
- 238000010586 diagram Methods 0.000 description 5
- 230000008569 process Effects 0.000 description 5
- 238000004364 calculation method Methods 0.000 description 4
- 230000000630 rising effect Effects 0.000 description 4
- 230000000087 stabilizing effect Effects 0.000 description 4
- 230000009286 beneficial effect Effects 0.000 description 2
- 238000011084 recovery Methods 0.000 description 2
- 230000001360 synchronised effect Effects 0.000 description 2
- 230000003139 buffering effect Effects 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 230000009977 dual effect Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000001105 regulatory effect Effects 0.000 description 1
- 230000004044 response Effects 0.000 description 1
- 230000002441 reversible effect Effects 0.000 description 1
Classifications
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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
- F24F11/00—Control or safety arrangements
- F24F11/30—Control or safety arrangements for purposes related to the operation of the system, e.g. for safety or monitoring
- F24F11/32—Responding to malfunctions or emergencies
- F24F11/37—Resuming operation, e.g. after power outages; Emergency starting
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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
- F24F11/00—Control or safety arrangements
- F24F11/30—Control or safety arrangements for purposes related to the operation of the system, e.g. for safety or monitoring
- F24F11/32—Responding to malfunctions or emergencies
- F24F11/38—Failure diagnosis
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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
- F24F11/00—Control or safety arrangements
- F24F11/62—Control or safety arrangements characterised by the type of control or by internal processing, e.g. using fuzzy logic, adaptive control or estimation of values
- F24F11/63—Electronic processing
- F24F11/64—Electronic processing using pre-stored data
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F24—HEATING; RANGES; VENTILATING
- F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
- F24F11/00—Control or safety arrangements
- F24F11/70—Control systems characterised by their outputs; Constructional details thereof
- F24F11/80—Control systems characterised by their outputs; Constructional details thereof for controlling the temperature of the supplied air
- F24F11/86—Control systems characterised by their outputs; Constructional details thereof for controlling the temperature of the supplied air by controlling compressors within refrigeration or heat pump circuits
Abstract
The invention discloses a compressor frequency control method and an air conditioning unit, wherein the compressor frequency control method comprises the following steps: after each fault compressor clears the fault, the power-on starting is performed again; the fault compressors firstly run for a certain time at a set starting frequency, then the running frequency is increased at a set frequency increasing speed, and all normal compressors regulate the running frequency in a state of temperature change of a user side; the fault compressors are connected with the normal compressors in parallel, the temperature change state of the user side comprises a change trend, when the change trend of the temperature of the user side is stable, whether the fault compressors reach the normal state is judged, if yes, the fault compressors reaching the normal state are marked as the normal compressors, and the running frequencies of the fault compressors and other normal frequency compressors are consistent. The invention controls the operation frequency of the fault compressor and the normal compressor respectively, not only can ensure the stable start of the fault compressor, but also can avoid the great fluctuation of the temperature of the user side, and effectively improves the reliability and the use experience of the air conditioning unit.
Description
Technical Field
The invention relates to the technical field of air conditioners, in particular to a compressor frequency control method and an air conditioner unit.
Background
Air conditioning units on the market at present meet the energy-saving requirement, variable frequency compressors are widely used for compressors, and air conditioning units with single variable frequency compressors are most common, but in special application occasions such as limiting the types of variable frequency compressors and large heat exchange amount, in order to obtain higher performance and reliability, a design scheme of double compressors or multiple compressors is often adopted. Taking a double-frequency conversion compressor system as an example, when one compressor is stopped due to failure, temperature fluctuation can be avoided, and after the failed compressor is recovered, a control scheme for restarting the failed compressor to operate is important for controlling the temperature fluctuation.
The starting control scheme in the prior art is designed for synchronous frequency adjustment of two compressors, the two compressors are respectively subjected to frequency adjustment under the condition that the two compressors are started, when one of the compressors needs to be increased in frequency, whether the running frequency of the one compressor is greater than that of the other compressor is judged, and if so, the current frequency running is continuously kept; if not, frequency raising is carried out on the filter; when one of the compressors needs to be frequency-reduced, judging whether the operation frequency of the compressor is greater than that of the other compressor, if so, frequency-reducing the other compressor; if not, the current frequency operation is kept continuously.
The control scheme can balance the operation frequencies of the two compressors, ensures that the operation frequencies of the two compressors are basically consistent as much as possible, but is not applicable to the situation that the unit is re-connected after the fault compressor is recovered, because the operation frequency of the fault compressor is lower than that of the normal compressor in a longer time after the fault compressor is started, the fault compressor and the normal compressor can keep the frequency adjustment speed until the operation frequencies of the fault compressor and the normal compressor are the same, and the adjustment mode completely ignores the temperature fluctuation of a user side in the synchronization process of the two compressors, thereby seriously affecting the use experience.
Therefore, how to design a frequency control method and an air conditioning unit suitable for the fault recovery of a compressor is a technical problem to be solved in the industry.
Disclosure of Invention
In order to solve the defect of large temperature fluctuation of a user side of the existing control scheme, the invention provides a compressor frequency control method and an air conditioning unit, which are used for respectively controlling the operating frequencies of a fault compressor and a normal compressor, so that the stable starting of the fault compressor can be ensured, the temperature fluctuation of the user side can be avoided, and the reliability and the use experience of the air conditioning unit are effectively improved.
The technical scheme adopted by the invention is that the method for controlling the frequency of the compressor is designed and comprises the following steps:
after each fault compressor clears the fault, the power-on starting is performed again;
the fault compressors firstly run for a certain time at a set starting frequency, then the running frequency is increased at a set frequency increasing speed, and all normal compressors regulate the running frequency in a state of temperature change of a user side;
wherein the faulty compressor and the normal compressor are connected in parallel.
Further, the temperature change state of the user terminal comprises a change trend; in the refrigeration mode, the normal compressor adjusting the operating frequency in a state of a user side temperature change includes:
when the change trend of the temperature of the user side is an increasing trend, the operating frequency of the normal compressor is increased;
when the change trend of the temperature of the user side is stable, judging whether the fault compressor reaches a normal state, if so, marking the fault compressor reaching the normal state as a normal compressor and keeping the running frequency of the fault compressor reaching the normal state consistent with that of other normal frequency compressors;
and when the change trend of the temperature of the user side is a decreasing trend, the operating frequency of the normal compressor is decreased.
Further, the temperature change state of the user terminal comprises a change trend; in the heating mode, the normal compressor adjusts the operating frequency in a state of temperature change of the user side, including:
when the change trend of the temperature of the user side is an increasing trend, the operating frequency of the normal compressor is reduced;
when the change trend of the temperature of the user side is stable, judging whether the fault compressor reaches a normal state, if so, marking the fault compressor reaching the normal state as a normal compressor and keeping the running frequency of the fault compressor reaching the normal state consistent with that of other normal frequency compressors;
and when the change trend of the temperature of the user side is a decreasing trend, the operating frequency of the normal compressor is increased.
Further, the calculation mode of the change trend of the temperature of the user terminal is as follows:；
when (when)When the temperature of the user side is more than 0, judging that the change trend of the temperature of the user side is an increasing trend;
when (when)When the temperature of the user terminal is=0, judging that the change trend of the temperature of the user terminal is stable;
when (when)When the temperature of the user side is less than 0, judging that the change trend of the temperature of the user side is a decreasing trend;
wherein t is the detection time of the temperature of the user terminal,for the time interval between the two detection,and the temperature of the user terminal corresponding to the time t.
Further, the temperature change state of the user terminal further comprises a change amplitude; the normal compressor adjusts the operating frequency according to the temperature change state of the user side, and the normal compressor comprises the following components:
a comparison relation between the variation amplitude and the frequency adjustment time interval is established in advance;
calculating the change amplitude of the temperature of the user side and acquiring a corresponding frequency adjustment time interval from the comparison relation;
controlling the operating frequency of the normal compressor according to the frequency adjustment time interval;
wherein, the larger the variation amplitude is, the shorter the corresponding frequency adjustment time interval is.
Further, the calculation mode of the change amplitude of the temperature of the user terminal is as follows:the comparison relation is the comparison relation between the grading interval of the variation amplitude and the frequency adjustment time interval.
Further, determining whether the faulty compressor reaches a normal state includes:
judging whether the difference value of the operating frequencies of the normal compressor and the fault compressor is smaller than or equal to a set value;
if yes, the fault compressor reaches a normal state;
if not, the fault compressor does not reach the normal state.
Further, the adjusting the operating frequency of the normal compressor according to the state of temperature change of the user terminal further includes:
when the change trend of the temperature of the user side is kept stable, judging whether each fault compressor which is restarted by electrifying is switched to a normal compressor;
if not, the fault compressor continues to increase the operating frequency at the set frequency increasing speed, and the normal compressor continues to adjust the operating frequency in a state of temperature change of the user side;
if so, all normal compressors resume normal control.
Further, the conventional control calculates a target operating frequency according to the operating parameters of the unit where the normal compressors are located, and uniformly adjusts all the normal compressors according to the target operating frequency.
Further, all compressors are of the same model.
Further, the starting frequency is set to the lowest operating frequency of the compressor.
Further, the amplitude of each frequency adjustment of the normal compressor is the same.
The invention also provides an air conditioning unit, which comprises: a refrigerant circulation loop having at least two compressors connected in parallel; the air conditioning unit adopts the compressor frequency control method.
Compared with the prior art, the invention has the following beneficial effects:
1. the fault compressors firstly run for a certain time at a set starting frequency, then the running frequency is increased at a set frequency increasing speed, and all normal compressors regulate the running frequency in a state of temperature change of a user side, so that the stable starting of the fault compressors can be ensured, the temperature fluctuation of the user side can be avoided, and the reliability and the use experience of the air conditioning unit are improved;
2. after all the fault compressors are switched into normal compressors, the operating frequencies of the normal compressors are regulated according to the conventional control logic, so that the operating frequencies of all the started compressors are ensured to be consistent, and the operating stability of the air conditioning unit is improved.
Drawings
The invention is described in detail below with reference to examples and figures, wherein:
FIG. 1 is a schematic diagram of the connection of a single cooling air conditioning unit of the present invention;
FIG. 2 is a flow chart of a control method according to all embodiments of the present invention;
FIG. 3 is a schematic flow chart of a control method of the single-cooling air conditioning unit of the invention;
FIG. 4 is a schematic diagram of a frequency variation curve of the single cooling air conditioning unit of the present invention;
FIG. 5 is a schematic diagram of a first refrigerant flow of the single cooling air conditioning unit according to the present invention;
FIG. 6 is a schematic diagram of a second refrigerant flow of the single cooling air conditioning unit according to the present invention;
FIG. 7 is a schematic diagram of a third refrigerant flow of the single cooling air conditioning unit according to the present invention;
description of the drawings: 1. a variable frequency compressor; 11. a first compressor; 12. a second compressor; 2. a one-way valve; 3. a condenser; 4. a throttle device; 5. an evaporator.
Detailed Description
In order to make the technical problems, technical schemes and beneficial effects to be solved more clear, the invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are for purposes of illustration only and are not intended to limit the scope of the invention.
As shown in fig. 1, the compressor frequency control method provided by the invention is suitable for air conditioning units, including but not limited to single-cooling air conditioning units, wherein the air conditioning unit is provided with at least two variable frequency compressors, and each variable frequency compressor is connected in parallel in a refrigerant circulation loop of the air conditioning unit.
Specifically, taking a single-cooling air conditioning unit as an example, the air conditioning unit includes: at least two variable frequency compressors 1, a condenser 3, a throttling device 4 and an evaporator 5 which are connected to form a refrigerant circulation loop, wherein the inlets of the condenser 3 are respectively connected with the exhaust ports of the two variable frequency compressors 1, and the outlets of the evaporator 5 are respectively connected with the air inlets of the two variable frequency compressors 1. Each variable frequency compressor 1 can be independently controlled, and the refrigerant circulation loop can normally operate by starting any variable frequency compressor 1. In some embodiments of the present invention, the air outlet of each inverter compressor 1 is provided with a check valve 2, and the check valve 2 only allows the refrigerant to flow to the condenser 3, so as to prevent the occurrence of the reverse flow of the refrigerant when two or more inverter compressors 1 are turned on.
It should be understood that, for an air conditioning unit having a cooling mode and a heating mode, the refrigerant circulation loop further has a four-way valve for switching the flow direction of the refrigerant, which is mainly exemplified herein as a single-cooling air conditioning unit, but the compressor frequency control method may also be applied to an air conditioning unit having a heating mode, where the control method is applied between the cooling mode and the heating mode only in that the rising and falling frequencies corresponding to the change trend are different, and the rest of the control logics are the same.
In the operation process of the air conditioning unit, at least one compressor is stopped due to failure reasons such as high-pressure protection, high-temperature protection or overload protection, after the default compressor fails, the refrigerating capacity of the unit can be reduced, and the operation frequency of the rest normal compressors is immediately improved after any one compressor fails to ensure normal cooling of the unit. The operating frequency of the normal compressor is usually raised to the highest operating frequency or the target operating frequency, and when the target operating frequency is higher than the highest operating frequency, the normal compressor is raised to the highest operating frequency, and when the target operating frequency is lower than the highest operating frequency, the normal compressor is raised to the target operating frequency.
After the fault compressor recovers/clears the fault, the restarting of the fault compressor is controlled by the frequency control method provided by the invention, so that the problem that the temperature fluctuation of a user side is overlarge in the process of accessing the fault compressor into a unit, and the user/a cooled object is influenced is avoided.
As shown in fig. 2, based on an air conditioning unit having at least two compressors connected in parallel, the control method provided by the present invention includes:
after each fault compressor clears the fault, the power-on starting is performed again;
the fault compressors are operated for a certain time at a set starting frequency, then the operating frequency is increased at a set frequency increasing speed, and all normal compressors are operated at a user side temperature change state.
The design has the advantages that the stability of the fault compressor connected to the air conditioning unit is improved, the fault compressor runs for a certain time corresponding to a buffering stage after power-on starting at a set starting frequency, the set starting frequency is preferably the lowest running frequency of the compressor, namely, the fault compressor runs for a certain time at the lowest running frequency after power-on starting again, and the time can be designed according to actual use requirements. The fault compressor then promotes the running frequency with the speed of setting for the rising frequency, ensures that the fault compressor starts steadily, promotes air conditioning unit's reliability, and normal compressor adjusts the running frequency with user side temperature change state, avoids user side temperature to fluctuate by a wide margin, and user side temperature keeps stable at the in-process that fault compressor inserts the unit, promotes user's use experience.
It should be understood that the compressors present in the control method of the present invention are all variable frequency compressors.
As shown in fig. 3, in some embodiments of the present invention, the state of change of the temperature of the user side includes a trend of change, and the adjusting logic of the normal compressor operating frequency in the cooling mode includes:
when the change trend of the temperature of the user side is an increasing trend, the output capacity of the started compressor is smaller and the refrigeration requirement cannot be met, so that the operating frequency of the normal compressor is increased (if the normal compressor is at the highest operating frequency, the current frequency is kept continuously), the heat exchange capacity of the evaporator is increased, and the purpose of stabilizing or reducing the temperature of the user side is achieved;
when the change trend of the temperature of the user side is stable, the output capacity of the started compressor is moderate, after the temperature of the user side is stable, whether the fault compressor reaches a normal state is judged, if so, the fault compressor reaching the normal state is marked as a normal compressor and the running frequency of the fault compressor is consistent with that of other normal frequency compressors;
when the change trend of the temperature of the user terminal is a decreasing trend, the output capacity of the started compressor is larger, and the operating frequency of the normal compressor is reduced, so that the heat exchange amount of the evaporator is reduced, and the purpose of stabilizing or increasing the temperature of the user terminal is achieved.
It should be understood that, since the output capacity of the started compressor increases after the failed compressor is restarted, if the operating frequency of the normal compressor remains unchanged, the trend of the change in the temperature of the user terminal is a decreasing trend. That is, during the re-connection of the faulty compressor to the unit, the operating frequency of the normal compressor generally assumes a gradually decreasing state as the frequency of the faulty compressor gradually increases. After the temperature of the user side is stable, the fault compressor reaching the normal state is switched to the normal compressor, so that the operation frequency difference between the compressors is prevented from being too large, and the reliability of the air conditioning unit is improved.
In some embodiments of the present invention, the user side temperature change state includes a trend of change, and the adjusting logic of the normal compressor operating frequency in the heating mode includes:
when the change trend of the temperature of the user terminal is an increasing trend, the output capacity of the started compressor is larger, and the running frequency of the normal compressor is reduced, so that the heat exchange amount of the condenser is reduced, and the purpose of stabilizing or reducing the temperature of the user terminal is achieved;
when the change trend of the temperature of the user side is stable, the output capacity of the started compressor is moderate, after the temperature of the user side is stable, whether the fault compressor reaches a normal state is judged, if so, the fault compressor reaching the normal state is marked as a normal compressor and the running frequency of the fault compressor is consistent with that of other normal frequency compressors;
when the variation trend of the temperature of the user terminal is a decreasing trend, the output capacity of the started compressor is smaller, and the heating requirement cannot be met, so that the operating frequency of the normal compressor is increased (if the normal compressor is at the highest operating frequency, the current frequency is kept continuously), the heat exchange capacity of the condenser is increased, and the purpose of stabilizing or increasing the temperature of the user terminal is achieved.
In some embodiments of the present invention, the calculation method of the trend of the temperature of the user terminal is as follows:；
when (when)When the temperature of the user side is more than 0, judging that the change trend of the temperature of the user side is an increasing trend;
when (when)When the temperature of the user terminal is=0, judging that the change trend of the temperature of the user terminal is stable;
when (when)When the temperature of the user side is less than 0, judging that the change trend of the temperature of the user side is a decreasing trend;
wherein t is the detection time of the temperature of the user terminal,for the time interval between the two detection,the temperature of the user terminal corresponding to the time t,the difference between the user terminal temperature detected at the last time and the user terminal temperature detected at the previous time is used as the difference.
It should be noted that, taking the cooling mode as an example, the cooling capacity of the air conditioning unit will change immediately after the failed compressor is powered on again, and the operating frequencies of the failed compressor and the normal compressor continuously change before the unit resumes the normal control, in order to achieve a more stable control of the user side temperature,can be properly shortened, and after all the failed compressors are switched to the normal compressors, the refrigerating capacity of the air conditioning unit is relatively stable,the operation state of the air conditioning unit can be prevented from being frequently adjusted by proper extension, and the stability is improved.
That is, it is preferable that the fault compressor is restarted after power-onLess than after the air conditioning unit resumes normal controlAfter the fault compressor is powered on again and started, the detection time interval of the temperature of the user terminal is shortened immediately, the change state of the temperature of the user terminal is monitored more accurately, and the temperature of the user terminal is prevented from fluctuating greatly.
In some embodiments of the present invention, the user side temperature change state further includes a change amplitude, and the adjusting logic for the normal compressor operation frequency further includes:
a comparison relation between the variation amplitude and the frequency adjustment time interval is established in advance;
calculating the variation amplitude of the temperature of the user side and acquiring a corresponding frequency adjustment time interval from the comparison relation;
controlling the operating frequency of the normal compressor according to the frequency adjustment time interval;
the larger the variation amplitude is, the shorter the corresponding frequency adjustment time interval is.
It should be understood that, when the fault compressor recovers, in order to cope with the unnecessary intensity when the temperature of the user side fluctuates, the time interval of the frequency rising/falling of the normal compressor needs to be controlled, the response speed is high, and the temperature of the user side is prevented from greatly fluctuating.
In some embodiments of the present invention, the calculation method of the variation amplitude of the user side temperature is as follows:the comparison relation is the comparison relation between the grading interval of the variation amplitude and the frequency adjustment time interval.
For ease of understanding, an example of application of the present invention will be described as an exampleThe method is divided into three sections, each section is designed with a corresponding frequency adjustment time interval, and the comparison relation is as follows:
when 0 <When a is less than or equal to a, the frequency adjustment time interval of the normal compressor is a1 second;
when a < >When b is less than or equal to b, the frequency adjustment time interval of the normal compressor is a2 seconds;
when b < >When c is less than or equal to c, the frequency adjustment time interval of the normal compressor is a3 seconds;
wherein a1 > a2 > a3.
It should be understood that, in practical application, only the trend of the temperature of the user side may be selected as the control condition for adjusting the normal compressor, but the preferred scheme is to select the trend of the temperature of the user side and the range of the change together as the control condition for adjusting the normal compressor.
In addition, in order to avoid that the compressor greatly adjusts the frequency to influence the running stability of the air conditioning unit, the preferable scheme is to control the normal compressor to have the same frequency adjustment amplitude each time.
As shown in fig. 3, in some embodiments of the present invention, determining whether the failed compressor reaches a normal state includes:
judging whether the difference value of the operating frequency of the normal compressor and the operating frequency of the fault compressor is smaller than or equal to a set value, namely judging whether the operating frequency of the normal compressor minus the operating frequency of the fault compressor is smaller than or equal to the set value;
if so, indicating that the operating frequency of the fault compressor is similar to that of the normal compressor, or the operating frequency of the fault compressor is increased to exceed that of the normal compressor, wherein the frequency-increasing time of the fault compressor is sufficient and the state is stable, so that the fault compressor is judged to reach the normal state;
if not, the difference between the operating frequencies of the fault compressor and the normal compressor is larger, the frequency rising time of the fault compressor is insufficient, and the stability of the fault compressor is influenced by greatly adjusting the operating frequency of the fault compressor, so that the fault compressor is judged to not reach the normal state.
It should be noted that, because the present invention is applicable to application scenarios of more than two compressors, supporting recovery of faulty compressors simultaneously or one by one or more, the normal compressor adjusting the operating frequency in a state of temperature change at the user side further includes:
when the change trend of the temperature of the user terminal is kept stable, judging whether each fault compressor which is restarted by powering on is switched to a normal compressor;
if not, indicating that the fault compressor which is restarted after the power-on does not reach a normal state, continuously lifting the operating frequency at a set frequency-increasing speed by the fault compressor, and continuously adjusting the operating frequency by the normal compressor according to a temperature change state of a user side;
if yes, the fault compressors which are restarted by the power-on are all in a normal state, the running frequencies of the started compressors are kept consistent, the air conditioning unit is recovered to normal operation, and the normal compressors are controlled conventionally.
The conventional control mentioned above is to calculate the target operating frequency according to the operating parameters of the unit where the normal compressors are located, uniformly adjust all the normal compressors according to the target operating frequency, and the calculating mode of the target operating frequency can be selected from the prior art, which is not particularly limited in the present invention.
It should be pointed out that all the compressors are the same in model, and the air conditioning unit can synchronous adjustment all the compressors that have opened when normal operation, and the life of compressor is unanimous basically, and air conditioning unit operating stability is better.
For the sake of understanding, taking an application example of the present invention as an example, as shown in fig. 1, the air conditioning unit has two variable frequency compressors 1, the condenser 3 adopts a fin type heat exchanger, the evaporator 5 adopts a plate type heat exchanger, two heat exchange pipelines of the evaporator 5 are respectively used for circulating refrigerant and water, the temperature of the user side mentioned in the control method is the outlet water temperature of the evaporator 5, the first compressor 11 is used as a fault compressor, and the second compressor 12 is used as a normal compressor.
The operating frequency change conditions of the first compressor 11 and the second compressor 12 are shown in fig. 4, when the air conditioning unit is powered on and started, the first compressor 11 and the second compressor 12 are both normal compressors, the unit performs conventional control on the compressors, and both compressors are at the target operating frequency. After the first compressor 11 is stopped in a fault, the operating frequency of the second compressor 12 is immediately increased to maintain the output capacity of the unit and avoid the great fluctuation of the outlet water temperature.
After the first compressor 11 recovers/clears the fault, the power-on start is restarted, the operation is performed for a period of time under the set starting frequency, and the unit immediately shortens the time interval for detecting the water outlet temperatureFirst, theThe two compressors 12 adjust the operation frequency in a state of changing the temperature of the discharged water, and the operation frequency of the second compressor 12 is reduced more smoothly at this stage.
Then the first compressor 11 increases the operation frequency at a set frequency increasing speed, the second compressor 12 continues to adjust the operation frequency in a state of variation in the outlet water temperature, after the outlet water temperature is stable, the difference value between the operation frequency of the second compressor 12 and the operation frequency of the first compressor 11 is judged, after the difference value is smaller than the set value, the first compressor 11 is switched to a normal compressor, the operation frequency of the first compressor 11 is adjusted to be consistent with the operation frequency of the second compressor 12, and then the unit resumes the normal control.
It should be noted that fig. 4 is only used for exemplary purposes, and does not represent that the operating frequency of the dual compressor system must be designed according to the curve, and the frequency variation curves of the normal compressor and the fault compressor may be different according to different practical application scenarios, which is based on the control logic of the present invention.
The invention also provides an air conditioning unit, which comprises: and the refrigerant circulation loop is provided with at least two compressors connected in parallel, and the controller of the air conditioning unit executes the compressor frequency control method, so that the temperature fluctuation of a user side caused by restarting of the fault compressor is effectively reduced.
For the sake of understanding, taking an application example of the present invention as an example, as shown in fig. 1, the air conditioning unit has two variable frequency compressors 1, the condenser 3 adopts a fin type heat exchanger, the throttling device 4 adopts an electronic expansion valve, the evaporator 5 adopts a plate type heat exchanger, the two variable frequency compressors 1 are respectively a first compressor 11 and a second compressor, the evaporator 5 has two heat exchange pipelines for exchanging heat with each other, one of the two heat exchange pipelines is connected in a refrigerant circulation loop, the other heat exchange pipeline is connected to a user side device, and the user side device supplies cold to a user through the user side device, and the user side device includes but is not limited to a fan coil.
As shown in fig. 5, when only the first compressor 11 is turned on, the refrigerant flow direction is the discharge of the first compressor 11, the check valve 2, the condenser 3, the throttle device 4, the evaporator 5, and the return to the first compressor 11;
as shown in fig. 6, when only the second compressor 12 is turned on, the refrigerant flow direction is the second compressor 12 discharge→the check valve 2→the condenser 3→the throttle device 4→the evaporator 5→the return to the second compressor 12;
as shown in fig. 7, when the first compressor 11 and the second compressor 12 are turned on, the refrigerant flow direction is the discharge of the first compressor 11 and the second compressor 12, the check valve 2, the condenser 3, the throttle device 4, the evaporator 5, and the return to the first compressor 11 and the second compressor 12.
It is noted that the above-mentioned terms are used merely to describe specific embodiments, and are not intended to limit exemplary embodiments according to the present invention. When the terms "comprises" and/or "comprising" are used in this specification, they specify the presence of stated features, steps, operations, devices, components, and/or groups thereof. The order of execution of the operations, steps, and the like in the apparatuses and methods shown in the specification and the drawings may be any order as long as the order is not particularly limited, and the output of the preceding process is not used in the following process. The use of ordinal-like terms for descriptive convenience does not necessarily imply that they are necessarily implemented in such order.
Techniques, methods, and apparatus known to one of ordinary skill in the relevant art may not be discussed in detail, but should be considered part of the specification where appropriate. In all examples shown and discussed herein, any specific values should be construed as merely illustrative, and not a limitation. Thus, other examples of the exemplary embodiments may have different values. It should be noted that: like reference numerals and letters denote like items in the following figures, and thus once an item is defined in one figure, no further discussion thereof is necessary in subsequent figures.
The foregoing description of the preferred embodiments of the invention is not intended to be limiting, but rather is intended to cover all modifications, equivalents, and alternatives falling within the spirit and principles of the invention.
Claims (12)
1. A compressor frequency control method, comprising:
after each fault compressor clears the fault, the power-on starting is performed again;
the fault compressors firstly run for a certain time at a set starting frequency, then the running frequency is increased at a set frequency increasing speed, and all normal compressors regulate the running frequency in a state of temperature change of a user side;
wherein the faulty compressor and the normal compressor are connected in parallel.
2. The compressor frequency control method of claim 1, wherein the user side temperature change state includes a change trend; in the refrigeration mode, the normal compressor adjusting the operating frequency in a state of a user side temperature change includes:
when the change trend of the temperature of the user side is an increasing trend, the operating frequency of the normal compressor is increased;
when the change trend of the temperature of the user side is stable, judging whether the fault compressor reaches a normal state, if so, marking the fault compressor reaching the normal state as a normal compressor and keeping the running frequency of the fault compressor reaching the normal state consistent with that of other normal frequency compressors;
and when the change trend of the temperature of the user side is a decreasing trend, the operating frequency of the normal compressor is decreased.
3. The compressor frequency control method of claim 1, wherein the user side temperature change state includes a change trend; in the heating mode, the normal compressor adjusts the operating frequency in a state of temperature change of the user side, including:
when the change trend of the temperature of the user side is an increasing trend, the operating frequency of the normal compressor is reduced;
when the change trend of the temperature of the user side is stable, judging whether the fault compressor reaches a normal state, if so, marking the fault compressor reaching the normal state as a normal compressor and keeping the running frequency of the fault compressor reaching the normal state consistent with that of other normal frequency compressors;
and when the change trend of the temperature of the user side is a decreasing trend, the operating frequency of the normal compressor is increased.
4. The compressor frequency control method according to claim 2 or 3, wherein the trend of the user side temperature is calculated by:；
when (when)When the temperature of the user side is more than 0, judging that the change trend of the temperature of the user side is an increasing trend;
when (when)When the temperature of the user terminal is=0, judging that the change trend of the temperature of the user terminal is stable;
when (when)When the temperature of the user side is less than 0, judging that the change trend of the temperature of the user side is a decreasing trend;
wherein t is the detection time of the temperature of the user terminal,for the time interval of two detection before and after, < + >>And the temperature of the user terminal corresponding to the time t.
5. A compressor frequency control method according to claim 2 or 3, wherein the user side temperature change state further includes a change amplitude; the normal compressor adjusts the operating frequency according to the temperature change state of the user side, and the normal compressor comprises the following components:
a comparison relation between the variation amplitude and the frequency adjustment time interval is established in advance;
calculating the change amplitude of the temperature of the user side and acquiring a corresponding frequency adjustment time interval from the comparison relation;
controlling the operating frequency of the normal compressor according to the frequency adjustment time interval;
wherein, the larger the variation amplitude is, the shorter the corresponding frequency adjustment time interval is.
6. The compressor frequency control method of claim 5, wherein the magnitude of change in the user side temperature is calculated by:the comparison relation is the comparison relation between the grading interval of the variation amplitude and the frequency adjustment time interval;
wherein,t is the detection time of the temperature of the user terminal, < >>For the time interval of two detection before and after, < + >>And the temperature of the user terminal corresponding to the time t.
7. The compressor frequency control method of claim 2, wherein determining whether the faulty compressor reaches a normal state comprises:
judging whether the difference value of the operating frequencies of the normal compressor and the fault compressor is smaller than or equal to a set value;
if yes, the fault compressor reaches a normal state;
if not, the fault compressor does not reach the normal state.
8. The compressor frequency control method of claim 2, wherein the normal compressor adjusting the operating frequency in a state of a user side temperature change further comprises:
when the change trend of the temperature of the user side is kept stable, judging whether each fault compressor which is restarted by electrifying is switched to a normal compressor;
if not, the fault compressor continues to increase the operating frequency at the set frequency increasing speed, and the normal compressor continues to adjust the operating frequency in a state of temperature change of the user side;
if so, all normal compressors resume normal control.
9. The compressor frequency control method as set forth in claim 8, wherein said normal control is to calculate a target operating frequency according to an operating parameter of a unit in which said normal compressor is located, and to uniformly adjust all normal compressors according to said target operating frequency.
10. The compressor frequency control method of claim 1, wherein all of the compressors are identical in model number.
11. The compressor frequency control method of claim 1, wherein the amplitude of each frequency adjustment of the normal compressor is the same.
12. An air conditioning unit comprising: a refrigerant circulation loop having at least two compressors connected in parallel; the compressor frequency control method according to any one of claims 1 to 11 is used for the air conditioning unit.
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Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6826917B1 (en) * | 2003-08-01 | 2004-12-07 | York International Corporation | Initial pull down control for a multiple compressor refrigeration system |
| CN107860146A (en) * | 2017-10-19 | 2018-03-30 | 无锡职业技术学院 | A kind of control method of air source heat pump system |
| CN111435048A (en) * | 2019-01-11 | 2020-07-21 | 青岛经济技术开发区海尔热水器有限公司 | Frequency control method of variable frequency compressor and heat pump unit |
| CN112303855A (en) * | 2020-11-04 | 2021-02-02 | 珠海格力电器股份有限公司 | Control method of double-compressor air conditioning unit and air conditioning unit |
| CN114294789A (en) * | 2021-12-23 | 2022-04-08 | 珠海格力电器股份有限公司 | Control method of air conditioning system, air conditioning system and air conditioner |
| CN114877431A (en) * | 2022-04-20 | 2022-08-09 | 中车青岛四方机车车辆股份有限公司 | Active redundant air conditioning unit and control method |
-
2023
- 2023-12-22 CN CN202311775179.3A patent/CN117450623B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6826917B1 (en) * | 2003-08-01 | 2004-12-07 | York International Corporation | Initial pull down control for a multiple compressor refrigeration system |
| CN107860146A (en) * | 2017-10-19 | 2018-03-30 | 无锡职业技术学院 | A kind of control method of air source heat pump system |
| CN111435048A (en) * | 2019-01-11 | 2020-07-21 | 青岛经济技术开发区海尔热水器有限公司 | Frequency control method of variable frequency compressor and heat pump unit |
| CN112303855A (en) * | 2020-11-04 | 2021-02-02 | 珠海格力电器股份有限公司 | Control method of double-compressor air conditioning unit and air conditioning unit |
| CN114294789A (en) * | 2021-12-23 | 2022-04-08 | 珠海格力电器股份有限公司 | Control method of air conditioning system, air conditioning system and air conditioner |
| CN114877431A (en) * | 2022-04-20 | 2022-08-09 | 中车青岛四方机车车辆股份有限公司 | Active redundant air conditioning unit and control method |
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