CN110657550B - Compressor oil return control method and device and air conditioner - Google Patents

Compressor oil return control method and device and air conditioner Download PDF

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CN110657550B
CN110657550B CN201910998268.1A CN201910998268A CN110657550B CN 110657550 B CN110657550 B CN 110657550B CN 201910998268 A CN201910998268 A CN 201910998268A CN 110657550 B CN110657550 B CN 110657550B
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compressor
frequency
temperature
interval
air conditioner
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CN110657550A (en
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朱礼晋
李存永
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Ningbo Aux Electric Co Ltd
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Ningbo Aux Electric Co Ltd
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    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24HEATING; RANGES; VENTILATING
    • F24FAIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
    • F24F11/00Control or safety arrangements
    • F24F11/30Control or safety arrangements for purposes related to the operation of the system, e.g. for safety or monitoring
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24HEATING; RANGES; VENTILATING
    • F24FAIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
    • F24F11/00Control or safety arrangements
    • F24F11/62Control or safety arrangements characterised by the type of control or by internal processing, e.g. using fuzzy logic, adaptive control or estimation of values
    • F24F11/63Electronic processing
    • F24F11/64Electronic processing using pre-stored data
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24HEATING; RANGES; VENTILATING
    • F24FAIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
    • F24F11/00Control or safety arrangements
    • F24F11/70Control systems characterised by their outputs; Constructional details thereof
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F24HEATING; RANGES; VENTILATING
    • F24FAIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
    • F24F11/00Control or safety arrangements
    • F24F11/88Electrical aspects, e.g. circuits
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25BREFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B31/00Compressor arrangements
    • F25B31/002Lubrication
    • F25B31/004Lubrication oil recirculating arrangements
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25BREFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
    • F25B49/00Arrangement or mounting of control or safety devices
    • F25B49/02Arrangement or mounting of control or safety devices for compression type machines, plants or systems
    • F25B49/022Compressor control arrangements

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  • Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Physics & Mathematics (AREA)
  • Signal Processing (AREA)
  • Thermal Sciences (AREA)
  • Fuzzy Systems (AREA)
  • Mathematical Physics (AREA)
  • Air Conditioning Control Device (AREA)

Abstract

The invention relates to the technical field of air conditioners, in particular to an air conditioner compressor oil return control method and device and an air conditioner. A plurality of connecting pipes which are mutually connected in parallel are arranged between a compressor and an indoor heat exchanger of the air conditioner, and the oil return control method comprises the following steps: acquiring the running frequency of a compressor; when the operation of the compressor reaches a set condition, acquiring the pressure of a refrigerant in the connecting pipe; and controlling the opening and closing of each connecting pipe according to the refrigerant pressure and the operating frequency, wherein the number of the connecting pipes is reduced as the refrigerant pressure is lower and the operating frequency is lower. Therefore, whether the compressor returns oil normally or not is directly judged by the pressure of the refrigerant matched with the monitoring of the frequency of the compressor; the plurality of connecting pipes which are connected in parallel are arranged between the indoor heat exchanger and the compressor, and the sum of the sectional areas of all the connected connecting pipes is indirectly changed by changing the number of the connected connecting pipes, so that the flow rate of the refrigerant in the connecting pipes is changed, and the normal oil return of the compressor under the low-frequency operation is realized.

Description

Compressor oil return control method and device and air conditioner
Technical Field
The invention relates to the technical field of air conditioners, in particular to a compressor oil return control method and device and an air conditioner.
Background
Generally, a compressor needs to be lubricated and cooled by lubricating oil during operation, and when the compressor exhausts air, a part of lubricating oil in the compressor can be taken out by refrigerant gas passing through the compressor, so that the oil is retained in a pipeline of an air conditioning system, and the oil loss is caused. When the compressor of the air conditioning system runs at low frequency, the flow rate of the refrigerant in the pipeline is low, so that oil return is difficult. In the conventional oil return method, after the compressor runs for a certain time at low frequency, the running frequency is increased, the flow of a refrigerant in a system is increased, the flow rate of the refrigerant is increased, and after oil return is finished, the compressor runs at low frequency again. As the compressor operating frequency fluctuates, the system capacity also fluctuates, thereby affecting the comfort of the system.
Disclosure of Invention
The present invention is directed to solving the above problems and solving at least one of the problems.
In order to solve the above problems, the present invention provides an oil return control method for an air conditioner compressor, wherein a plurality of connecting pipes connected in parallel are arranged between the air conditioner compressor and an indoor heat exchanger, and the oil return control method comprises:
acquiring the running frequency of the compressor;
when the operation of the compressor reaches a set condition, acquiring the pressure of a refrigerant in the connecting pipe;
and controlling the connection pipes to be opened and closed according to the refrigerant pressure and the operating frequency, wherein the connection pipes are opened less frequently as the refrigerant pressure is lower and the operating frequency is lower.
Therefore, whether the compressor returns oil normally or not is directly judged by the pressure of the refrigerant matched with the monitoring of the frequency of the compressor. The connecting pipes which are connected in parallel are arranged between the indoor heat exchanger and the compressor, the connecting pipes with different numbers are selectively opened, the sum of the sectional areas of all the connected connecting pipes is indirectly changed by changing the number of the connected connecting pipes, and the pipe diameter of the connecting pipe which is connected between the indoor heat exchanger and the compressor is indirectly changed, so that the flow rate of refrigerant in the connecting pipes is changed, and normal oil return of the compressor under low-frequency operation is realized.
Optionally, before the obtaining of the refrigerant pressure in the connecting pipe, the method further includes:
acquiring the time of the compressor running at the set frequency,
the setting condition includes that the time of the compressor running at a first setting frequency is accumulated to reach a first setting time, wherein the first setting time is longer when the first setting frequency is higher.
Therefore, the operation relation between different frequencies and set time can be preset in the system, the operation relation is directly called when the compressor is controlled to operate, and when the operation frequency of the compressor changes, the set time can be timely adjusted. When the running frequency of the compressor is increased, the set time can be adjusted in real time, and the set time is shortened; when the operating frequency of the compressor is reduced, the set time is extended.
Optionally, after acquiring the time of the compressor operating at the set frequency cumulatively, before controlling the opening and closing of each of the connection pipes according to the refrigerant pressure and the operating frequency, the method further includes:
and when the compressor operates at the second set frequency for the second set time, clearing the time of the compressor operating at the set frequency in an accumulated mode, and acquiring the time of the compressor operating at the set frequency in an accumulated mode again.
Therefore, the method for real-time monitoring is set to avoid the untimely response caused by the change of the operating frequency of the compressor, and the operation of the compressor is adjusted in real time according to the real-time operating frequency.
Optionally, before the obtaining the operating frequency of the compressor, the method further includes:
all the connecting pipes are opened.
Therefore, the air conditioner resources can be utilized to the maximum extent, and the operating efficiency of the air conditioner is improved.
Optionally, the controlling the opening and closing of each connection pipe (2) according to the refrigerant pressure and the operating frequency includes:
when the operating frequency is in a first frequency interval and the refrigerant pressure is in a first pressure interval, closing one of the connecting pipes;
when the operating frequency is in a second frequency interval and the refrigerant pressure is in a second pressure interval, closing two connecting pipes;
only opening one connecting pipe until the operating frequency is in an Nth frequency interval and the refrigerant pressure is in an Nth pressure interval; wherein any frequency value in the N-1 frequency interval is larger than any frequency value in the N frequency interval; any pressure value in the Nth-1 th pressure interval is larger than any pressure value in the Nth pressure interval; n is more than or equal to 2 and is a positive integer.
Therefore, the judgment is more accurate by combining the frequency of the compressor with the double judgment conditions of the pressure of the refrigerant, and the judgment of the on-off of the connecting pipe is triggered only when the pressure of the refrigerant reaches the set conditions.
Optionally, the air conditioner further includes an auxiliary branch, one end of the auxiliary branch is communicated with the exhaust port of the compressor, the other end of the auxiliary branch is communicated with the suction port of the compressor through the connecting pipe, and the compressor oil return control method further includes:
acquiring the return air temperature of the compressor in real time;
and controlling the on-off of the auxiliary branch according to the return air temperature.
From this, when operating to the compressor low frequency, the oil return effect that the pipe diameter that changes the connecting pipe can reach is limited, and at this moment, through the control to the break-make of auxiliary branch road, can increase the refrigerant temperature, the lubricity of reinforcing oil further promotes the oil return effect of compressor.
Optionally, controlling the auxiliary branch to be turned on or off according to the return air temperature includes:
when the return air temperature is in a first temperature interval, opening the auxiliary branch;
when the return air temperature is in a third temperature interval, closing the auxiliary branch;
when the return air temperature is in a second temperature interval, maintaining the current state of the auxiliary branch;
any temperature value in the first temperature interval is larger than any temperature value in the second temperature interval, and any temperature value in the second temperature interval is larger than any temperature value in the third temperature interval.
Therefore, when the return air temperature meets the set temperature, the on-off of the auxiliary branch is controlled according to the size of the return air temperature.
The invention also provides an oil return control device of the air conditioner compressor, which comprises:
the air conditioner comprises a compressor, an indoor heat exchanger, a plurality of connecting pipes, a plurality of air conditioning units and a plurality of air conditioning units, wherein the compressor is arranged in the indoor heat exchanger;
an acquisition unit for acquiring an operating frequency of the compressor;
the control unit is used for acquiring the pressure of the refrigerant in the connecting pipe when the operation of the compressor reaches a set condition;
the control unit is further configured to control opening and closing of each of the connection pipes according to the refrigerant pressure and the operating frequency, wherein the number of the connection pipes that are opened is smaller as the refrigerant pressure is lower and the operating frequency is lower. Therefore, the connecting pipes which are connected in parallel are arranged between the indoor heat exchanger and the compressor, the connecting pipes with different numbers are selectively opened, the sum of the sectional areas of all the connected connecting pipes is indirectly changed by changing the number of the connected connecting pipes, and the pipe diameter of the connecting pipe connected between the indoor heat exchanger and the compressor is indirectly changed, so that the flow rate of refrigerant in the connecting pipes is changed, and normal oil return of the compressor under low-frequency operation is realized.
Optionally, the method further comprises: one of the connecting pipes is kept in a normally open state, and the other connecting pipes are provided with first electromagnetic valves which are in communication connection with the control unit.
Therefore, the on-off of the connecting pipe is controlled by the on-off of the electromagnetic valve.
Optionally, there are two electromagnetic valves in each connecting pipe, and the two electromagnetic valves are respectively disposed at two ends of the connecting pipe.
Therefore, the flow rate of the refrigerant in the connecting pipe is timely responded by the mode that the electromagnetic valves are respectively arranged at the two ends, and the refrigerant can be prevented from continuously flowing back to the connecting pipe after the electromagnetic valves are closed.
Optionally, the compressor oil return control device further comprises:
one end of the auxiliary branch is communicated with an exhaust port of the compressor, and the other end of the auxiliary branch is communicated with an air suction port of the compressor through the connecting pipe;
the acquisition unit is used for acquiring the return air temperature of the compressor;
the control unit is also used for controlling the on-off of the auxiliary branch according to the return air temperature.
Therefore, the return air temperature of the compressor is monitored, the on-off of the auxiliary branch is controlled according to the return air temperature, part of high-temperature gaseous refrigerant is mixed with the refrigerant in the connecting pipe, the temperature of the refrigerant in the connecting pipe is improved, the lubricating property of oil in the pipeline is improved, and the oil return rate is improved.
Optionally, the obtaining unit includes a temperature sensor, the temperature sensor is in communication connection with the control unit, and the temperature sensor is disposed at a suction port of the compressor.
Therefore, the return air temperature of the compressor is monitored by the temperature sensor.
Optionally, a second solenoid valve is disposed in the auxiliary branch, and the second solenoid valve is in communication connection with the control unit.
Therefore, the on-off of the auxiliary branch is controlled by the on-off of the electromagnetic valve.
The invention also provides an air conditioner which comprises any one of the compressor oil return control devices. The air conditioner and the oil return control device have the same beneficial effects, and are not described again.
Drawings
FIG. 1 is a schematic structural diagram of an oil return control device of a compressor according to an embodiment of the present invention;
FIG. 2 is a schematic diagram illustrating a connection relationship between an oil return control device of a compressor according to an embodiment of the present invention;
FIG. 3 is a flow chart of a method for controlling oil return to a compressor according to an embodiment of the present invention;
fig. 4 is a flowchart of a compressor oil return control method according to another embodiment of the present invention.
Description of reference numerals:
1-compressor, 2-connecting pipe, 3-throttling device, 4-auxiliary branch, 5-second electromagnetic valve, 6-first electromagnetic valve, 7-obtaining unit and 8-control unit.
Detailed Description
In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in detail below.
In addition, all directions or positional relationships mentioned in the embodiments of the present invention are positional relationships based on the drawings, and are only for convenience of describing the present invention and simplifying the description, but do not imply or imply that the referred device or element must have a specific orientation, and are not to be construed as limiting the present invention. In the description of the present invention, "a plurality" means two or more unless otherwise specified. "first," "second," etc. do not denote any particular quantity, but rather are merely used for convenience of distinction and description.
Generally, in the operation process of an air conditioner, the low-frequency oil return difficulty of a compressor mainly occurs in a pipeline with gaseous refrigerant, wherein the pipeline from the compressor to an outdoor heat exchanger is short and can be ignored; and the length of the connecting pipe from the compressor to the indoor heat exchanger is longer, so that the oil quantity is reserved greatly.
As shown in fig. 1, when the air conditioner performs a cooling mode, a high-temperature and high-pressure gaseous refrigerant discharged from the compressor 1 flows to the outdoor heat exchanger, condenses the gaseous refrigerant into a liquid refrigerant, flows to the indoor heat exchanger through the throttling device 3, and the indoor heat exchanger absorbs indoor heat to gasify the liquid refrigerant to form the gaseous refrigerant, and returns to the air suction port of the compressor 1 to complete a cooling cycle. When the air conditioner executes a heating mode, high-temperature and high-pressure gaseous refrigerant discharged by the compressor 1 firstly flows to the indoor heat exchanger, the gaseous refrigerant is condensed into liquid refrigerant and releases heat to the indoor space, the liquid refrigerant formed by condensation of the indoor heat exchanger flows to the outdoor heat exchanger after passing through the throttling device 3, the outdoor heat is absorbed, the liquid refrigerant is gasified to form gaseous refrigerant, the gaseous refrigerant returns to an air suction port of the compressor 1, and one heating cycle is completed.
The idea of the present invention is to change the flow rate of the refrigerant in the connecting pipe 2, which is related to the pipe diameter of the connecting pipe 2, and when the pipe diameter of the connecting pipe 2 is reduced by half, the flow rate of the refrigerant is increased by one time. For compressors 1 with different frequencies, different refrigerant flow rates need to correspond to different connecting pipe diameters.
The embodiment of the invention provides an oil return control device of an air conditioner compressor, which comprises: the air conditioner comprises a compressor, an indoor heat exchanger, a plurality of connecting pipes, a plurality of air conditioning units and a plurality of air conditioning units, wherein the compressor is arranged in the indoor heat exchanger;
an acquisition unit 7 for acquiring an operating frequency of the compressor;
the control unit 8 is used for acquiring the pressure of the refrigerant in the connecting pipe 2 when the operation of the compressor 1 reaches a set condition;
the control unit 8 is further configured to control opening and closing of each of the connection pipes 2 according to the refrigerant pressure and the operating frequency, wherein the number of the connection pipes 2 that are opened is smaller as the refrigerant pressure is lower and the operating frequency is lower.
That is, a single connection pipe between the compressor 1 and the indoor heat exchanger is replaced with a plurality of connection pipes 2 connected in parallel, the pipe diameter of each connection pipe 2 is smaller than that of the single connection pipe before replacement, but the sum of the pipe diameters of all the connection pipes 2 after replacement is equal to that of the single connection pipe before replacement. In practice, due to the limitation of the specification of the connecting pipes 2, the sum of the pipe diameters of all the connecting pipes 2 after replacement is not necessarily equal to the pipe diameter of the single connecting pipe before replacement, and here, it is required to ensure that the difference between the sum of the inner circular areas of all the connecting pipes 2 after replacement and the inner circular area of the single connecting pipe before replacement is within a certain error range, and the maximum value of the error is 10%, that is, the difference is
Figure GDA0003181134830000071
Here, S1For connecting the pipe diameters of the single pipes before replacement, S2Is the sum of the pipe diameters of all the connecting pipes 2 after replacement.
In one embodiment of the present embodiment, there are four connecting pipes 2, and four connecting pipes 2 are connected in parallel. Conventional copper pipe specifications (outside diameter by wall thickness) include:
Figure GDA0003181134830000072
Figure GDA0003181134830000073
Figure GDA0003181134830000074
and
Figure GDA0003181134830000077
etc. therefore, the specification is
Figure GDA0003181134830000075
The connecting single tube can adopt four specifications as
Figure GDA0003181134830000078
Is replaced by a connecting pipe 2 with the specification of
Figure GDA0003181134830000076
The connecting single tube can adopt four specifications as
Figure GDA0003181134830000079
Connecting tube 2 instead.
It should be noted that one of the connection pipes is kept in a normally open state, and the other connection pipes are provided with first electromagnetic valves, as shown in fig. 1 and 2, and the first electromagnetic valves are in communication connection with the control unit. At least one of all the connecting pipes 2 connected in parallel is in a normally open state, i.e. always in a communicating state. A first solenoid valve 6 may be provided in the connection pipe 2 which is always in a communication state. The other connecting pipes 2 are provided with first electromagnetic valves 6. Because the length of connecting pipe 2 is longer, set up a solenoid valve and often can not guarantee the timely response of pipeline, at this moment, be provided with the quantity of first solenoid valve 6 in every connecting pipe 2 of first solenoid valve 6 and be two, two first solenoid valves 6 set up the both ends at every connecting pipe 2 respectively. The mode that the electromagnetic valves are arranged at the two ends respectively enables the flow velocity of the refrigerant in the connecting pipe to be responded in time, and the refrigerant can be prevented from continuously flowing back to the connecting pipe after the electromagnetic valves are closed. Of course, the on-off of the connecting pipe can be controlled by other types of valves, or other control methods not mentioned herein.
The embodiment of the invention provides an air conditioner, which comprises the air conditioner compressor oil return control device.
The advantage that sets up like this lies in, sets up many connecting pipes 2 that connect in parallel each other through setting up between indoor heat exchanger and compressor 1, selectively opens the connecting pipe 2 of different quantity, changes the sectional area sum of all connecting pipes that communicate through the quantity that changes the connecting pipe of intercommunication, changes the pipe diameter of connecting pipe 2 of intercommunication between indoor heat exchanger and the compressor 1 indirectly to change the refrigerant velocity of flow in connecting pipe 2, realize the normal oil return of compressor 1 under the low frequency operation.
The embodiment of the invention provides an oil return control device for an air conditioner compressor, which further comprises: one end of the auxiliary branch is communicated with an exhaust port of the compressor, and the other end of the auxiliary branch is communicated with an air suction port of the compressor through the connecting pipe;
an acquisition unit 7 for acquiring a return air temperature of the compressor;
the control unit 8 is further configured to control the on-off of the auxiliary branch according to the return air temperature.
It should be noted that the auxiliary branch 4 is connected in series with the connecting pipe 2 and the compressor 1 in the same circuit. The return air temperature is the suction air temperature of the compressor 1. The embodiment of the invention provides an oil return control device of a compressor, which further comprises: the acquisition module is also used for acquiring the return air temperature of the compressor 1; the control module is also used for controlling the on-off of the auxiliary branch 4 according to the return air temperature. It should be noted that the air conditioner includes the oil return control device for the compressor 1, and the control module is in communication connection with the second electromagnetic valve 5. And the on-off of the auxiliary branch 4 is controlled by controlling the on-off of the second electromagnetic valve 5. The acquisition unit is a temperature sensor, the temperature sensor is in communication connection with the control unit, and the temperature sensor is arranged at an air suction port of the compressor and used for monitoring the return air temperature of the compressor. And the return air temperature of the compressor is monitored in real time through the arrangement of the temperature sensor. As shown in fig. 1 and 2, a second solenoid valve is disposed in the auxiliary branch, and the second solenoid valve is in communication connection with the control unit.
The embodiment of the invention provides an air conditioner, which comprises the air conditioner compressor oil return control device.
The advantage that sets up like this lies in, through temperature sensor's setting, monitors compressor 1's return air temperature, according to return air temperature control the break-make of auxiliary branch 4 makes partial high temperature gaseous state refrigerant mix with the refrigerant in connecting pipe 2, improves the temperature of refrigerant in connecting pipe 2, has increased the lubricity of the oil in the pipeline, improves the oil return rate.
As shown in fig. 3, an embodiment of the present invention provides an oil return control method for a compressor of an air conditioner, in which a plurality of connecting pipes 2 connected in parallel are disposed between the compressor 1 and an indoor heat exchanger, and the oil return control method includes:
s2: acquiring the operating frequency of the compressor 1;
s3: when the operation of the compressor 1 reaches a set condition, acquiring the pressure of a refrigerant in the connecting pipe 2;
s4: and controlling the connection pipes 2 to be opened and closed according to the refrigerant pressure and the operating frequency, wherein the connection pipes 2 are opened less frequently as the refrigerant pressure is lower and the operating frequency is lower.
Here, when the normal oil return determination is performed only by the compressor frequency, the erroneous determination usually occurs, and the oil return is not necessarily performed when the set frequency is reached, and therefore, the compressor frequency is acquired in step S2, the refrigerant pressure is acquired from the operating frequency of the compressor by relaying the operation in step S3, and the normal oil return determination is directly performed on the compressor by monitoring the pressure of the refrigerant in accordance with the compressor frequency.
In step S3, before the step of obtaining the refrigerant pressure in the connection pipe 2, the method further includes:
the time for which the compressor 1 is operated cumulatively at a set frequency is acquired,
the setting condition includes that the time for which the compressor 1 is operated cumulatively at a first setting frequency reaches a first setting time, wherein the first setting time is longer as the first setting frequency is higher.
That is, the set time is different for different operating frequencies of the compressor 1. The higher the operating frequency of the compressor 1, the longer the set time; the lower the operating frequency of the compressor 1, the shorter the setting time. The reason is that when the frequency of the compressor 1 is sufficiently high, the flow rate of the refrigerant in the connection pipe is high, and the smoothness of the oil return is high, so that the on/off of the connection pipe can be adjusted after a long time. When the running frequency of the compressor is low, the flow rate of the refrigerant is low, at the moment, the set time is relatively short, and the on-off of the connecting pipe needs to be adjusted in time so as to change the flow rate of the refrigerant and improve the oil return amount.
In the embodiment of the invention, the first set frequency refers to that the operating frequency of the compressor meets a certain frequency value or is in a certain frequency interval, and when the first set frequency R1 of the compressor meets 30Hz < R1 < 40Hz, the first set time can be 60 minutes or other time; when the first set frequency R1 of the compressor meets the condition that R1 is more than 15Hz and less than or equal to 30Hz, the first set time can be 40 minutes or other time; when the first set frequency R1 of the compressor satisfies R1 ≦ 15Hz, the first set time may take 20 minutes or other time period. Although the refrigerant pressure is monitored in real time, the step S4 is performed only when the refrigerant pressure reaches a set value after the compressor 1 is operated for a set time.
The advantage of performing the connection and disconnection of the connection pipe after the set time is that since the compressor 1 is always running, the oil in the system can ensure the normal operation of the air conditioner within a certain time, and after the compressor runs for the set time, the oil in the connection pipe 2 may be more. And at the moment, whether the compressor returns oil normally is directly judged according to the pressure of the refrigerant. And selectively closing the connection pipe according to the operating frequency of the compressor.
Here, the operation relationship between the different frequencies and the set time may be preset in the system, and the operation relationship may be directly called when the compressor is controlled to operate, and of course, a curve relationship between the different frequencies and the set time may be established, and the set time may be adjusted in time when the operation frequency of the compressor 1 is changed. When the running frequency of the compressor 1 is increased, the set time can be adjusted in real time, and the set time is prolonged; when the operating frequency of the compressor 1 is decreased, the set time is shortened.
Here, the method for acquiring the time for which the compressor 1 is operated at the set frequency cumulatively and before controlling the opening and closing of each of the connection pipes 2 according to the refrigerant pressure and the operation frequency further includes:
when the compressor 1 operates at the second set frequency R2 for the second set time, the time of the compressor 1 operating at the set frequency is cleared, and the time of the compressor 1 operating at the set frequency is acquired again.
Since the frequency of the compressor 1 may change during the operation of the compressor 1, when the operation frequency of the compressor is greater than a second set frequency and the frequency of the compressor 1 is greater than the second set frequency and continues to operate for a set accumulated time, the set time needs to be determined again according to the current frequency of the compressor. In an embodiment of the present invention, the second set frequency is 50Hz, the operating frequency of the compressor is always greater than 50Hz, and the compressor continues to operate for 8 minutes, and then the cumulative operating time of the compressor is determined again according to the current operating frequency. The advantage of this arrangement is that it avoids the change of the running frequency of the compressor, which results in the untimely response, and sets the real-time monitoring method, and makes the real-time adjustment to the running of the compressor according to the real-time running frequency.
As shown in fig. 4, before the step of S2, it also generally includes S1: all the connecting tubes 2 are opened. In step S1, there are a plurality of connection pipes, the plurality of connection pipes are connected in parallel and are disposed between a compressor and an indoor heat exchanger of an air conditioner, and in an initial state, all the connection pipes 2 are controlled to be opened, that is, the control device controls all the first electromagnetic valves 6 in the connection pipes 2 to be opened, so that all the connection pipes 2 are in a connected state. Therefore, the air conditioner resources can be utilized to the maximum extent, and the operating efficiency of the air conditioner is improved.
In step S4, the step of selectively closing the connection pipe 2 only according to the operating frequency may include:
when the operating frequency R is in a first frequency interval, closing one of the connecting pipes 2;
when the operating frequency R is in a second frequency interval, two of the connecting pipes 2 are closed;
and repeating the steps until only one of the connecting pipes 2 is opened when the operating frequency R is in the nth frequency interval, wherein no frequency intersection exists between the first frequency interval and the nth frequency interval of the second frequency interval … …, any frequency value in the nth-1 frequency interval is greater than any frequency value in the nth frequency interval, N is greater than or equal to 2, and N is a positive integer.
Here, when the operation frequency R is greater than any frequency value of the first frequency interval, all the connection pipes 2 maintain the current state. In one embodiment of the present invention, there are four connecting pipes, and when the operating frequency of the compressor 1 is greater than 40Hz, four connecting pipes 2 keep the current state; when the running frequency R of the compressor meets the condition that R is more than 30Hz and less than or equal to 40Hz, one connecting pipe 2 is closed; when the running frequency R of the compressor meets the condition that R is more than 15Hz and less than or equal to 30Hz, two connecting pipes 2 are closed; when the running frequency R of the compressor meets the condition that R is less than or equal to 15Hz, three connecting pipes 2 are closed, namely, only one connecting pipe 2 is kept communicated. Here, the size of the value of the specific frequency interval is not limited.
The advantage of setting up like this is that, the quantity of connecting pipe 2 of direct foundation of the operating frequency of compressor 1 confirms the flow area of refrigerant to realize the change to the velocity of flow of refrigerant, realize the quick oil return of compressor.
In an embodiment of the present invention, the controlling of the opening and closing of each of the connection pipes 2 according to the refrigerant pressure and the operation frequency includes:
when the operating frequency R is in a first frequency interval and the set pressure is in a first pressure interval, closing one of the connecting pipes;
when the operating frequency R is in a second frequency interval and the set pressure is in a second pressure interval, closing two of the connecting pipes;
in the same way, only one of the connecting pipes is opened when the running frequency R is in the Nth frequency interval and the set pressure is in the Nth pressure interval; wherein, there is no frequency intersection between the first frequency interval and the Nth frequency interval of the second frequency interval … …, and any frequency value in the Nth-1 frequency interval is greater than any frequency value in the Nth frequency interval; wherein, there is no pressure intersection between the first pressure interval and the Nth pressure interval of the second pressure interval … …, and any pressure value in the Nth-1 pressure interval is larger than any pressure value in the Nth pressure interval; wherein N is more than or equal to 2 and is a positive integer.
In one embodiment of the present invention, there are four connecting pipes, and when the operating frequency of the compressor 1 is greater than 40Hz and the refrigerant pressure is greater than 2MPa, the four connecting pipes 2 maintain the current state; when the running frequency R of the compressor meets the conditions that R is more than 30Hz and less than or equal to 40Hz and the pressure P of the refrigerant meets the conditions that P is more than 1.8MPa and less than or equal to 2MPa, one connecting pipe 2 is closed; when the operating frequency R of the compressor meets the conditions that R is more than 15Hz and less than or equal to 30Hz and the pressure P of the refrigerant meets the conditions that P is more than 1.7MPa and less than or equal to 1.8MPa, two connecting pipes 2 are closed; when the operating frequency R of the compressor meets the condition that R is less than or equal to 15Hz and the refrigerant pressure P meets the condition that P is less than or equal to 1.8MPa, three connecting pipes 2 are closed, namely only one connecting pipe 2 is kept to be communicated. Here, the size of the value of the specific frequency interval and pressure interval is not limited, and the value of the frequency interval and pressure interval may be other values. The advantage that sets up like this lies in, combines the dual judgement condition of refrigerant pressure through compressor frequency, makes and judges more accurately, only when refrigerant pressure reaches the settlement condition, just triggers the judgement of connecting pipe break-make.
In an embodiment of the present invention, the compressor oil return control method further includes:
acquiring the return air temperature of the compressor in real time;
and controlling the on-off of the auxiliary branch according to the return air temperature, wherein one end of the auxiliary branch is communicated with an exhaust port of the compressor, and the other end of the auxiliary branch is communicated with an air suction port of the compressor through the connecting pipe.
Here, the real-time acquisition of the return air temperature of the compressor is not limited to the step S1, the step S2, the step S3 or the step S4, and this arrangement has an advantage that the oil return effect that can be achieved by changing the pipe diameter of the connecting pipe 2 is limited when the compressor operates at a low frequency, and at this time, the refrigerant temperature can be increased, the lubricity of oil can be enhanced, and the oil return effect of the compressor can be further improved by controlling the on-off of the auxiliary branch.
Here, controlling the opening and closing of the auxiliary branch 4 according to the return air temperature includes: when the return air temperature T is in a first temperature interval, opening the auxiliary branch 4; when the return air temperature T is in a third temperature interval, closing the auxiliary branch 4; when the return air temperature T is in a second temperature interval, keeping the current state of the auxiliary branch 4; the temperature control device comprises a first temperature interval, a second temperature interval and a third temperature interval, wherein the first temperature interval, the second temperature interval and the third temperature interval have no temperature intersection, any temperature value in the first temperature interval is smaller than any temperature value in the second temperature interval, and any temperature value in the second temperature interval is smaller than any temperature value in the third temperature interval.
In one embodiment of the invention, when the return air temperature T is less than or equal to 4 ℃, the second electromagnetic valve 5 is opened, and the auxiliary branch 4 is opened; when the return air temperature T is more than or equal to 6 ℃, closing the second electromagnetic valve 5 and closing the auxiliary branch 4; and when the return air temperature T meets 4 ℃ and T is less than 6 ℃, keeping the current state of the auxiliary branch 4. Of course, the values of the different temperature intervals are not absolute, and the values of the temperature of the different temperature intervals can be set according to actual working conditions. And when the return air temperature meets the set temperature, controlling the on-off of the auxiliary branch according to the size of the return air temperature.
Although the present invention is disclosed above, the present invention is not limited thereto. Various changes and modifications may be effected therein by one skilled in the art without departing from the spirit and scope of the invention as defined in the appended claims.

Claims (10)

1. The utility model provides an air conditioner compressor oil return control method, its characterized in that, be provided with a plurality of connecting pipes (2) that connect in parallel each other between compressor (1) and the indoor heat exchanger of air conditioner, the air conditioner still includes supplementary branch road (4), the one end of supplementary branch road (4) with the gas vent intercommunication of compressor (1), the other end of supplementary branch road (4) passes through connecting pipe (2) with the induction port intercommunication of compressor (1), oil return control method includes:
acquiring the operating frequency of the compressor (1); acquiring the accumulated running time of the compressor (1) at a set frequency, and acquiring the return air temperature of the compressor (1) in real time;
when the operation of the compressor (1) reaches a set condition, acquiring the pressure of a refrigerant in the connecting pipe (2); wherein the set condition comprises that the time of the compressor (1) running at a first set frequency is accumulated to reach a first set time, wherein the first set time is longer when the first set frequency is higher; extending the first set time when the operating frequency of the compressor (1) increases; shortening the first set time when the operating frequency of the compressor (1) is reduced;
controlling the opening and closing of each connecting pipe (2) according to the refrigerant pressure and the operating frequency, wherein the connecting pipes (2) are opened less when the refrigerant pressure is lower and the operating frequency is lower;
when the return air temperature is in a first temperature interval, opening the auxiliary branch (4);
when the return air temperature is in a third temperature interval, closing the auxiliary branch (4);
when the return air temperature is in a second temperature interval, keeping the current state of the auxiliary branch (4);
any temperature value in the first temperature interval is larger than any temperature value in the second temperature interval, and any temperature value in the second temperature interval is larger than any temperature value in the third temperature interval.
2. The method for controlling oil return of air conditioner compressor according to claim 1, wherein after obtaining the time of cumulative operation of the compressor (1) at the set frequency, before controlling the connection pipes (2) to open and close according to the refrigerant pressure and the operation frequency, the method further comprises:
when the compressor (1) operates at the second set frequency for the second set time, clearing the time of the compressor (1) operating at the set frequency in an accumulated mode, and acquiring the time of the compressor (1) operating at the set frequency in an accumulated mode again.
3. The air conditioner compressor oil return control method according to claim 1, characterized by further comprising, before said obtaining an operating frequency of the compressor (1):
opening all the connecting tubes (2).
4. The oil return control method for the compressor of the air conditioner as claimed in claim 3, wherein the controlling of the opening and closing of each connection pipe (2) according to the refrigerant pressure and the operation frequency comprises:
when the operating frequency is in a first frequency interval and the refrigerant pressure is in a first pressure interval, closing one of the connecting pipes (2);
when the operating frequency is in a second frequency interval and the refrigerant pressure is in a second pressure interval, closing two connecting pipes (2);
only one connecting pipe (2) is opened until the operating frequency is in an Nth frequency interval and the refrigerant pressure is in an Nth pressure interval;
wherein any frequency value in the N-1 frequency interval is larger than any frequency value in the N frequency interval; any pressure value in the Nth-1 th pressure interval is larger than any pressure value in the Nth pressure interval; wherein N is more than or equal to 2 and is a positive integer.
5. The utility model provides an air conditioner compressor oil return controlling means which characterized in that includes:
the air conditioner comprises a plurality of connecting pipes (2), wherein all the connecting pipes (2) are connected in parallel, and the connecting pipes (2) are arranged between a compressor (1) of the air conditioner and an indoor heat exchanger;
one end of the auxiliary branch (4) is communicated with an exhaust port of the compressor (1), the other end of the auxiliary branch (4) is communicated with an air suction port of the compressor (1) through the connecting pipe (2),
an acquisition unit (7) for acquiring an operating frequency of a compressor (1) and a time during which the compressor (1) is operated cumulatively at a set frequency;
the control unit (8) is used for acquiring the pressure of the refrigerant in the connecting pipe (2) when the operation of the compressor (1) reaches a set condition; wherein the set condition comprises that the time of the compressor (1) running at a first set frequency is accumulated to reach a first set time, wherein the first set time is longer when the first set frequency is higher; the control unit (8) is also adapted to control the first set time to be extended when the operating frequency of the compressor (1) increases; the control unit (8) is also adapted to control the first set time to be shortened when the operating frequency of the compressor (1) is reduced;
the control unit (8) is further configured to control opening and closing of each of the connection pipes (2) according to the refrigerant pressure and the operating frequency, wherein the number of the connection pipes (2) to be opened is smaller as the refrigerant pressure is lower and the operating frequency is lower;
when the return air temperature is in a first temperature interval, the control unit (8) is also used for opening the auxiliary branch (4);
when the return air temperature is in a third temperature interval, the control unit (8) is also used for closing the auxiliary branch (4);
when the return air temperature is in a second temperature interval, the control unit (8) is also used for keeping the current state of the auxiliary branch (4);
any temperature value in the first temperature interval is larger than any temperature value in the second temperature interval, and any temperature value in the second temperature interval is larger than any temperature value in the third temperature interval.
6. The air conditioner compressor oil return control device according to claim 5, wherein one of the connecting pipes (2) is kept in a normally open state, and the other connecting pipes (2) are provided with first electromagnetic valves (6), and the first electromagnetic valves (6) are in communication connection with the control unit (8).
7. The air conditioner compressor oil return control device as claimed in claim 6, wherein there are two first solenoid valves (6) in each connecting pipe (2), and the two first solenoid valves (6) are respectively disposed at both ends of the connecting pipe (2).
8. Air conditioner compressor oil return control device according to claim 7, characterized in that the acquisition unit (7) comprises a temperature sensor in communication connection with the control unit (8), the temperature sensor being arranged at the suction inlet of the compressor (1).
9. Air conditioner compressor oil return control device according to claim 8, characterized in that a second solenoid valve (5) is provided in the auxiliary branch (4), said second solenoid valve (5) being in communication connection with the control unit (8).
10. An air conditioner characterized by comprising the air conditioner compressor oil return control device as claimed in any one of claims 5 to 9.
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Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111397176B (en) * 2020-03-17 2021-03-12 珠海格力电器股份有限公司 High-temperature refrigeration control method and device and air conditioning equipment
CN114234501B (en) * 2021-12-21 2023-09-15 宁波奥克斯电气股份有限公司 Refrigerant recovery method, control device and refrigerant recovery device

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN107270517A (en) * 2017-07-26 2017-10-20 美的集团武汉制冷设备有限公司 Air-conditioning system, the control device of air-conditioning system and method

Family Cites Families (23)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP3807755B2 (en) * 1995-01-19 2006-08-09 三菱電機株式会社 Multi-room air conditioner
TW568254U (en) * 1997-01-06 2003-12-21 Mitsubishi Electric Corp Refrigerant circulating apparatus
CN1183366C (en) * 2001-06-15 2005-01-05 广东科龙电器股份有限公司 Return oil control method of refrigeration system
CN101561208B (en) * 2009-05-15 2010-12-08 宁波奥克斯电气有限公司 Method for controlling oil return of air conditioners
CN102128524B (en) * 2010-01-13 2012-11-21 珠海格力电器股份有限公司 Heat pump machine preheating method with preheating function
CN102645057A (en) * 2012-03-31 2012-08-22 宁波奥克斯电气有限公司 Oil returning method during heating of multi-split air-conditioning unit
CN104006504B (en) * 2014-06-19 2017-02-15 广东志高空调有限公司 Variable frequency air conditioner low-frequency operating control method and control device
CN104089347B (en) * 2014-06-24 2017-04-12 广东申菱环境系统股份有限公司 Low-temperature air-cooled water chiller unit and control method thereof
KR101550549B1 (en) * 2014-08-01 2015-09-04 엘지전자 주식회사 An air conditioner
CN104879966A (en) * 2015-04-29 2015-09-02 广东美的制冷设备有限公司 Frequency-variable air conditioner and control method thereof
CN105299979B (en) * 2015-10-15 2017-09-12 海信(山东)空调有限公司 Compressor method for controlling oil return, oil return apparatus and air conditioner
CN105299956B (en) * 2015-10-16 2019-01-25 珠海格力电器股份有限公司 Compressor oil return control device and method and air conditioner with device
CN205878690U (en) * 2016-07-30 2017-01-11 相宝军 Air conditioner oil returning device
CN107192103A (en) * 2017-05-23 2017-09-22 重庆美的通用制冷设备有限公司 Air-conditioning system, air-conditioner set and its oil return control system and method for controlling oil return
CN107449173B (en) * 2017-06-21 2019-10-18 广东志高空调有限公司 A kind of control method of domestic multi-connection formula frequency changer oil return control system
JP2019020080A (en) * 2017-07-20 2019-02-07 三菱重工サーマルシステムズ株式会社 Air conditioning device and operation method therefor
CN107270518B (en) * 2017-07-26 2020-05-05 美的集团武汉制冷设备有限公司 Air conditioning system, and control device and method of air conditioning system
CN109307384A (en) * 2018-08-08 2019-02-05 青岛海信日立空调系统有限公司 A kind of control method and device of oil return
CN109297151B (en) * 2018-10-22 2020-12-15 广东美的暖通设备有限公司 Oil return control method and device for air conditioning system, storage medium and air conditioning system
CN109612143A (en) * 2018-11-28 2019-04-12 宁波奥克斯电气股份有限公司 A kind of air-conditioning and its control method of the condenser that can be changed with heat exchange area
CN110131840B (en) * 2019-05-15 2021-05-14 宁波奥克斯电气股份有限公司 Oil return control method for variable frequency air conditioner and variable frequency air conditioner
CN110131925A (en) * 2019-05-16 2019-08-16 珠海格力电器股份有限公司 Oil return control method for compressor, compressor and heat exchange system
CN110332670A (en) * 2019-07-16 2019-10-15 珠海格力电器股份有限公司 Compressor control method and control device and refrigerant system

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN107270517A (en) * 2017-07-26 2017-10-20 美的集团武汉制冷设备有限公司 Air-conditioning system, the control device of air-conditioning system and method

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