CN115371308A - Liquid return prevention air conditioning system and control method - Google Patents
Liquid return prevention air conditioning system and control method Download PDFInfo
- Publication number
- CN115371308A CN115371308A CN202210991099.0A CN202210991099A CN115371308A CN 115371308 A CN115371308 A CN 115371308A CN 202210991099 A CN202210991099 A CN 202210991099A CN 115371308 A CN115371308 A CN 115371308A
- Authority
- CN
- China
- Prior art keywords
- expansion valve
- electronic expansion
- tss
- liquid
- air conditioning
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
- 239000007788 liquid Substances 0.000 title claims abstract description 107
- 238000004378 air conditioning Methods 0.000 title claims abstract description 35
- 238000000034 method Methods 0.000 title claims abstract description 22
- 230000002265 prevention Effects 0.000 title claims abstract description 14
- 238000010257 thawing Methods 0.000 claims abstract description 29
- 238000005057 refrigeration Methods 0.000 claims abstract description 23
- 102100033489 THO complex subunit 1 Human genes 0.000 claims description 11
- 101710139423 THO complex subunit 1 Proteins 0.000 claims description 11
- 102100033491 THO complex subunit 2 Human genes 0.000 claims description 3
- 101710139407 THO complex subunit 2 Proteins 0.000 claims description 3
- 238000001816 cooling Methods 0.000 claims description 3
- 239000003507 refrigerant Substances 0.000 abstract description 27
- 238000010438 heat treatment Methods 0.000 description 7
- 238000000926 separation method Methods 0.000 description 7
- 230000000694 effects Effects 0.000 description 3
- 238000005516 engineering process Methods 0.000 description 2
- 239000011550 stock solution Substances 0.000 description 2
- 102100036406 THO complex subunit 3 Human genes 0.000 description 1
- 101710139386 THO complex subunit 3 Proteins 0.000 description 1
- 102100036434 THO complex subunit 4 Human genes 0.000 description 1
- 101710139420 THO complex subunit 4 Proteins 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 230000007774 longterm Effects 0.000 description 1
- 239000013589 supplement Substances 0.000 description 1
Images
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B43/00—Arrangements for separating or purifying gases or liquids; Arrangements for vaporising the residuum of liquid refrigerant, e.g. by heat
- F25B43/006—Accumulators
-
- 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
- F24F11/41—Defrosting; Preventing freezing
-
- 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
- F24F11/49—Control or safety arrangements for purposes related to the operation of the system, e.g. for safety or monitoring ensuring correct operation, e.g. by trial operation or configuration checks
-
- 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
- F24F11/50—Control or safety arrangements characterised by user interfaces or communication
- F24F11/61—Control or safety arrangements characterised by user interfaces or communication using timers
-
- 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
- F24F11/62—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
- F24F11/65—Electronic processing for selecting an operating mode
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B41/00—Fluid-circulation arrangements
- F25B41/30—Expansion means; Dispositions thereof
- F25B41/31—Expansion valves
- F25B41/34—Expansion valves with the valve member being actuated by electric means, e.g. by piezoelectric actuators
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B41/00—Fluid-circulation arrangements
- F25B41/40—Fluid line arrangements
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25B—REFRIGERATION MACHINES, PLANTS OR SYSTEMS; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS
- F25B49/00—Arrangement or mounting of control or safety devices
- F25B49/02—Arrangement or mounting of control or safety devices for compression type machines, plants or systems
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F24—HEATING; RANGES; VENTILATING
- F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
- F24F2110/00—Control inputs relating to air properties
- F24F2110/10—Temperature
- F24F2110/12—Temperature of the outside air
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F24—HEATING; RANGES; VENTILATING
- F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
- F24F2140/00—Control inputs relating to system states
- F24F2140/10—Pressure
- F24F2140/12—Heat-exchange fluid pressure
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F24—HEATING; RANGES; VENTILATING
- F24F—AIR-CONDITIONING; AIR-HUMIDIFICATION; VENTILATION; USE OF AIR CURRENTS FOR SCREENING
- F24F2140/00—Control inputs relating to system states
- F24F2140/20—Heat-exchange fluid temperature
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02B—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS
- Y02B30/00—Energy efficient heating, ventilation or air conditioning [HVAC]
- Y02B30/70—Efficient control or regulation technologies, e.g. for control of refrigerant flow, motor or heating
Landscapes
- Engineering & Computer Science (AREA)
- General Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Chemical & Material Sciences (AREA)
- Physics & Mathematics (AREA)
- Combustion & Propulsion (AREA)
- Signal Processing (AREA)
- Thermal Sciences (AREA)
- Fuzzy Systems (AREA)
- Mathematical Physics (AREA)
- Power Engineering (AREA)
- Analytical Chemistry (AREA)
- Human Computer Interaction (AREA)
- Air Conditioning Control Device (AREA)
Abstract
The invention discloses a liquid return prevention air conditioning system and a control method, wherein the system comprises a four-way valve, a D port and an S port of the four-way valve are respectively communicated with a high-pressure pipeline and a low-pressure pipeline of a compressor, a gas-liquid separator is arranged on the low-pressure pipeline of the compressor, and an outdoor heat exchanger, a first electronic expansion valve, a second electronic expansion valve and an indoor heat exchanger are sequentially arranged between a C port and an E port of the four-way valve; a liquid storage tank is connected in parallel between the gas-liquid separator and the indoor heat exchanger, a third electronic expansion valve is arranged at one end of the liquid storage tank close to the indoor heat exchanger, and a fourth electronic expansion valve is arranged at the other end of the liquid storage tank. When the air conditioning unit system is in a minimum load refrigeration or defrosting mode, redundant refrigerants can enter the liquid storage tank only by adjusting the opening degree of the third electronic expansion valve and closing the fourth electronic expansion valve, the liquid return danger of the unit is solved under the condition that the running state of the unit is not influenced, and the stability of the system is guaranteed.
Description
Technical Field
The invention relates to the technical field of air conditioning systems, in particular to a liquid return prevention air conditioning system and a control method.
Background
The existing rotor type variable frequency air pipe machine is operated in a long-piping defrosting mode, and because the rotor compressor is large in oil consumption and the long piping needs to be additionally supplemented with redundant refrigerants, the liquid return phenomenon can occur when the air conditioning unit is operated in the defrosting mode for a long time, so that the rotor compressor can be operated with liquid, and the compressor can be damaged after long-term operation.
In the minimum load refrigeration mode, the unit does not need to run at full load, so that a large amount of refrigerants can be stored in a gas-liquid separator of the unit in the long-time running process of the unit, and even the refrigerants can overflow the gas-liquid separator and enter a compressor to be compressed in a liquid impact mode.
The existing defrosting control technology is that when the defrosting operation is performed, an internal and external electromechanical expansion valve of a unit is opened to the maximum opening, so that a large amount of refrigerant circulation fluctuation exists in a unit system when the unit enters the defrosting start, and a large amount of liquid returns by a gas-liquid separator transiently exceeds the liquid level at the warning position of the gas-liquid separator, so that the unit carries liquid; during defrosting operation, the unit system can gradually circulate along with the refrigerant after the four-way valve is switched, a large amount of refrigerants can gradually exist in the gas-liquid separator for defrosting, and meanwhile, the liquid level of the gas-liquid separator is gradually higher than the liquid level of the warning position along with the flowing amount of the refrigerants, so that the unit carries liquid.
The existing minimum load refrigeration technology is characterized in that the liquid carrying risk of a unit is reduced by gradually closing the opening degree of an electronic expansion valve of an inner unit in the operation process of the unit, but the problem of poor unit refrigeration effect caused by small refrigerant circulation quantity is indirectly caused.
Disclosure of Invention
The invention aims to provide a liquid return prevention air conditioning system and a control method, and aims to solve the problem that liquid is carried when an air conditioning unit operates in a defrosting and minimum load refrigeration mode in the prior art.
In order to achieve the purpose, the invention is realized by adopting the following technical scheme:
in a first aspect, the invention discloses a liquid return prevention air conditioning system which comprises a four-way valve, wherein a D port and an S port of the four-way valve are respectively communicated with a high-pressure pipeline and a low-pressure pipeline of a compressor, a gas-liquid separator is arranged on the low-pressure pipeline of the compressor, and an outdoor heat exchanger, a first electronic expansion valve, a second electronic expansion valve and an indoor heat exchanger are sequentially arranged between a C port and an E port of the four-way valve;
and a liquid storage tank is connected between the gas-liquid separator and the indoor heat exchanger in parallel, a third electronic expansion valve is arranged at one end of the liquid storage tank close to the indoor heat exchanger, and a fourth electronic expansion valve is arranged at the other end of the liquid storage tank.
Further, the liquid storage tank is connected in parallel between the indoor heat exchanger and an E port of the four-way valve.
Further, the liquid storage tank is connected in parallel between the S port of the four-way valve and the gas-liquid separator.
In a second aspect, a control method of a liquid-return prevention air conditioning system according to the first aspect of the present invention includes:
judging the operation mode of the unit system;
and when the unit system is in a defrosting and minimum load refrigerating mode, controlling the opening degree of the third electronic expansion valve according to the suction superheat degree change delta Tss, and closing the fourth electronic expansion valve to enable the liquid storage tank to store liquid.
Further, the controlling the opening degree of the third electronic expansion valve according to the intake superheat variation Δ Tss includes:
when the delta Tss is less than or equal to minus 4 ℃, the third electronic expansion valve is unloaded to the target opening degree at the speed of 8-10P/min;
when the temperature is lower than minus 4 ℃ and is less than delta Tss and less than 0 ℃, keeping the current opening degree of the third electronic expansion valve;
when the delta Tss is more than or equal to 0 ℃, loading the third electronic expansion valve to a target opening degree at the speed of 10-20P/min;
wherein, the change of the suction superheat degree delta Tss = Tss-Tss 1; tss is the intake superheat, and Tss1 is the target intake opening.
Wherein, the change of the suction superheat degree delta Tss = Tss-Tss 1; tss is the intake superheat degree, and Tss1 is the target intake opening degree.
Further, the step of judging the operation mode of the unit system comprises:
acquiring an outdoor ring temperature Tho1 and an outer disc temperature Tho2 of a unit system;
when the outdoor environment temperature Tho1 is less than 12 ℃, the temperature Tho1-Tho2 is less than 8 ℃, and the unit system operates for more than 40min, the unit system enters a defrosting mode;
and when the outdoor environment temperature Tho1 is less than 23 ℃ and the unit system operates for more than 4 hours, the unit system enters a minimum load refrigeration mode.
Further, when the air conditioner set is in a defrosting mode, the four-way valve is controlled to be powered off, the first electronic expansion valve is fully opened, and the second electronic expansion valve is fully opened.
Further, when the air conditioning unit is in the minimum load cooling mode, the second electronic expansion valve is controlled to the minimum opening degree.
Further, still include: and when the system is not in the defrosting and minimum load refrigeration modes, controlling the opening degree of the fourth electronic expansion valve according to the change of the suction superheat degree, and closing the third electronic expansion valve to separate liquid in the liquid storage tank.
Further, the controlling the opening degree of the fourth electronic expansion valve in accordance with the change in the suction superheat degree includes:
when the delta Tss is less than or equal to minus 4 ℃, the fourth electronic expansion valve is unloaded to the target opening degree at the speed of 8-10P/min;
when the temperature is lower than minus 4 ℃ and is less than delta Tss and less than 0 ℃, keeping the current opening degree of the fourth electronic expansion valve;
when the delta Tss is more than or equal to 0 ℃, loading the fourth electronic expansion valve to a target opening degree at the speed of 10-20P/min;
wherein, the change of the suction superheat degree delta Tss = Tss-Tss 1; tss is the intake superheat, and Tss1 is the target intake opening.
According to the technical scheme, the embodiment of the invention at least has the following effects:
1. according to the air conditioning system, the liquid storage tank is connected in parallel between the gas-liquid separator and the indoor heat exchanger, when the air conditioning system is in a minimum load refrigeration or defrosting mode, redundant refrigerants can enter the liquid storage tank only by adjusting the opening degree of the third electronic expansion valve and closing the fourth electronic expansion valve, the liquid return danger of a unit is solved under the condition that the running state of the unit is not influenced, and the stability of the system is guaranteed;
2. according to the control method of the air conditioning system, when the unit system is in a defrosting and minimum load refrigeration mode, the opening degree of the third electronic expansion valve is controlled according to the change of the suction superheat degree, the fourth electronic expansion valve is closed, redundant refrigerants can enter the liquid storage tank, the liquid return danger of the unit is solved under the condition that the running state of the unit is not influenced, and the stability of the system is guaranteed.
Drawings
FIG. 1 is a schematic view of an air conditioning system of the present invention;
FIG. 2 is a flow chart of the stock solution control of the present invention;
FIG. 3 is a schematic view of the third electronic expansion valve adjustment in the reservoir control of the present invention;
FIG. 4 is a flow chart of liquid separation control according to the present invention;
FIG. 5 is a schematic view of the fourth electronic expansion valve adjustment in the liquid separation control of the present invention;
FIG. 6 is a schematic diagram of another state of the air conditioning system of the present invention.
Wherein: 1. a compressor; 2. an oil separator; 3. a four-way valve; 4. an outdoor heat exchanger; 5a, a first electronic expansion valve; 5b, a second electronic expansion valve; 5c, a third electronic expansion valve; 5d, a fourth electronic expansion valve; 6. an indoor heat exchanger; 7. a liquid storage tank; 8. a gas-liquid separator; 9. and a throttling device.
Detailed Description
In order to make the technical means, the creation characteristics, the achievement purposes and the effects of the invention easy to understand, the invention is further explained by combining the specific embodiments.
It should be noted that in the description of the present invention, the terms "front", "back", "left", "right", "upper", "lower", "inner", "outer", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, which are only for convenience of description of the present invention and do not require that the present invention must be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention. As used in the description of the present invention, the terms "front," "back," "left," "right," "up," "down" and "in" refer to directions in the drawings, and the terms "inner" and "outer" refer to directions toward and away from, respectively, the geometric center of a particular component.
Example 1
As shown in fig. 1 and 6, the invention discloses a liquid return prevention air conditioning system, which comprises a four-way valve 3, wherein a D port and an S port of the four-way valve 3 are respectively communicated with a high-pressure pipeline and a low-pressure pipeline of a compressor 1, a gas-liquid separator 8 is arranged on the low-pressure pipeline of the compressor 1, and an outdoor heat exchanger 4, a first electronic expansion valve 5a, a second electronic expansion valve 5b and an indoor heat exchanger 6 are sequentially arranged between a port C and a port E of the four-way valve 3; a liquid storage tank 7 is connected in parallel between the gas-liquid separator 8 and the indoor heat exchanger 6, one end of the liquid storage tank 7 close to the indoor heat exchanger 6 is provided with a third electronic expansion valve 5c, and the other end is provided with a fourth electronic expansion valve 5d.
According to the air conditioning unit system, the liquid storage tank is connected in parallel between the gas-liquid separator and the indoor heat exchanger, when the air conditioning unit system is in a minimum load refrigeration or defrosting mode, redundant refrigerant can enter the liquid storage tank only by adjusting the opening degree of the third electronic expansion valve and closing the fourth electronic expansion valve, the liquid return danger of the unit is solved under the condition that the running state of the unit is not influenced, and the stability of the system is guaranteed.
As shown in fig. 1, in some further embodiments, the receiver tank 7 is configured to be connected in parallel between the indoor heat exchanger 6 and the E port of the four-way valve 3.
With the arrangement, the liquid storage tank 7 can play a role in liquid storage and liquid separation. Specifically, when the unit system is in a minimum load refrigeration or defrosting mode, the refrigerant flows to the four-way valve through the compressor, enters the outdoor heat exchanger 4 through the four-way valve, and then passes through the indoor heat exchanger 6. Because the liquid storage tank 7 is connected in parallel between the indoor heat exchanger 6 and the port E of the four-way valve 3, when the third electronic expansion valve 5c is opened, redundant refrigerant can enter the liquid storage tank for storage, and part of the refrigerant enters the compressor 1 after passing through the four-way valve 3 and the gas-liquid separator 8. When the unit system is in a refrigeration state (not including minimum load refrigeration), due to the increase of the refrigerant required by the system, the liquid separation release of the refrigerant can be realized by opening the fourth electronic expansion valve 5d, and the refrigeration capacity of the system is improved.
When the unit system is in a heating mode, the refrigerant flows to the four-way valve through the compressor and enters the indoor heat exchanger 6 through the four-way valve, and a large amount of refrigerant is needed in the heating process, so that the refrigerant in the liquid storage barrel can be separated and released by opening the fourth electronic expansion valve 5d, and then enters the compressor 1 after passing through the outdoor heat exchanger 4, the four-way valve 3 and the gas-liquid separator 8, so that the heating capacity is improved, and the use comfort of a user is guaranteed.
In other embodiments, as shown in fig. 6, a reservoir tank 7 is connected in parallel between the S port of the four-way valve 3 and the gas-liquid separator 8.
The design can realize the liquid storage function, namely, when the unit system is in a minimum load refrigeration or defrosting mode, redundant refrigerants are stored in the liquid storage tank 7.
In some further embodiments, an oil-liquid separator 2 and a throttling device 9 for reducing pressure and adjusting flow rate are also provided. The oil separator 2 is provided between the compressor 1 and the D port of the four-way valve, and the throttle device 9 is provided between the oil separator and the pipe line from the compressor 1 to the gas-liquid separator 8.
Example 2
The present embodiment provides a control method, which is based on the air conditioning unit system provided in embodiment 1 and includes liquid storage control and liquid separation control.
As shown in fig. 2 and 3, a method for controlling a liquid-return preventing air conditioning unit system includes:
judging the operation mode of the unit system;
and when the unit system is in a defrosting and minimum load refrigerating mode, controlling the opening degree of the third electronic expansion valve 5c according to the suction superheat degree change delta Tss, and closing the fourth electronic expansion valve 5d to enable the liquid storage tank 7 to store liquid.
According to the unit system control method, when the unit system is in a defrosting and minimum load refrigeration mode, the opening degree of the third electronic expansion valve 5c is controlled according to the change of the suction superheat degree, and the fourth electronic expansion valve 5d is closed, so that redundant refrigerants can enter the liquid storage tank, the liquid return danger of the unit is solved under the condition that the running state of the unit is not influenced, and the stability of the system is guaranteed.
In some specific embodiments, the process of the stock mode is as follows:
1) The unit judges whether to enter a defrosting or minimum load refrigeration working condition;
2) Acquiring an outdoor ring temperature Tho1 and an outer disc temperature Tho2 of the unit;
3) When the outdoor environment temperature Tho1 is less than 12 ℃ and Tho1-Tho2 is less than 8 ℃ and the running time is 40min, the unit judges to enter a defrosting mode; and when the outdoor environment temperature Tho1 is less than 23 ℃ and the running time is more than 4 hours, the unit judges that the minimum load refrigeration mode is entered.
4) In the defrosting mode, the four-way valve of the unit is powered off, the first electronic expansion valve 5a is fully opened, and the second electronic expansion valve 5b is fully opened. Further, in the minimum load refrigeration mode, the ring temperature Tho1 is less than 23 ℃, the high pressure is lower than 30bar, and at this time, the second electronic expansion valve 5b is controlled to be opened to the minimum opening degree.
5) The unit enters a liquid storage mode, the opening degree of a third electronic expansion valve 5c is adjusted to be opened according to the suction superheat degree, and a first/second electronic expansion valve enters corresponding refrigeration/heating control logic; the third electronic expansion valve 5c is adjusted according to the change of the suction superheat degree; the opening degree of the fourth electronic expansion valve 5d is controlled to 0.
6) Tss is defined as the suction superheat degree, and is the difference between the suction temperature and the saturation temperature corresponding to the low pressure; tss1 is defined as a target suction opening degree. Δ Tss = Tss — Tss1 is the actual suction superheat variation; the third electronic expansion valve 5c has the following regulation logic:
when the delta Tss is less than or equal to minus 4 ℃, the third electronic expansion valve 5c is subjected to load shedding control, and the load is reduced to the target opening degree (-8P, -10P)/60 s;
when the temperature is lower than minus 4 ℃ and is less than delta Tss and less than 0 ℃, the third electronic expansion valve 5c keeps the current opening degree;
when the delta Tss is more than or equal to 0 ℃, the third electronic expansion valve 5c is loaded and controlled, and the opening degree is controlled to be (+ 10P, + 20P)/60 s.
The initial opening degree and the target opening degree in the table can be used as reference, and in practical application, the machine set does not need to correspond to different values, and corresponding correction can be carried out, so that the actual regulation logic is taken as the standard.
In some further embodiments, the method for controlling a liquid return prevention air conditioning system further comprises: and when the system is not in the defrosting and minimum load refrigerating mode, the opening degree of the fourth electronic expansion valve 5d is controlled according to the change of the suction superheat degree, and the third electronic expansion valve 5c is closed to divide the liquid in the liquid storage tank 7.
In some specific embodiments, the process of the liquid separation mode is as follows:
1) And acquiring the operation mode of the unit.
2) And judging whether the unit is in refrigerating operation or heating operation.
3) And acquiring the outdoor ambient temperature Tho1 and the exhaust temperature Tho3 of the unit, converting the high pressure into the exhaust superheat degree, and adjusting the second electronic expansion valve 5b or the first electronic expansion valve 5a according to the exhaust superheat degree.
In this step, if the unit system is in a cooling state, the second electronic expansion valve 5b is adjusted according to the degree of exhaust superheat, and if the unit system is in a heating state, the first electronic expansion valve 5a is adjusted according to the degree of exhaust superheat.
4) Acquiring the suction temperature Tho4 of the unit, and converting the low pressure into the actual suction superheat degree change trend; .
5) The first/second electronic expansion valve enters corresponding refrigerating/heating control logic; adjusting the opening degree of the fourth electronic expansion valve 5d according to the change of the actual suction superheat degree; the opening degree of the third electronic expansion valve 5c is 0.
6) Judging whether the unit is in the working conditions of defrosting and minimum load refrigeration, if not, entering a liquid separation mode, and if so, entering a liquid storage mode;
7) Tss is defined as the suction superheat degree, and is the difference between the suction temperature and the saturation temperature corresponding to the low pressure; tss1 is defined as a target suction opening degree. Δ Tss = Tss — Tss1 is the actual suction superheat variation; the fourth electronic expansion valve adjustment logic is as follows:
when the delta Tss is less than or equal to minus 4 ℃, the fourth electronic expansion valve 5d is normally controlled, and the (+ 10P, + 20P)/60 s is loaded to the target opening degree;
when the temperature is lower than minus 4 ℃ and is less than delta Tss and less than 0 ℃, the fourth electronic expansion valve 5d keeps the current opening degree;
when the delta Tss is more than or equal to 0 ℃, the fourth electronic expansion valve 5d is subjected to load shedding control, and the load is reduced to the target opening degree (-8P, -10P)/60 s.
The initial opening degree and the target opening degree in the table can be used as reference, the machine set does not need to correspond to different values in practical application, corresponding correction can be carried out, and the actual regulation logic is used as the standard.
When the unit is in the working condition with more refrigerant demand, the fourth electronic expansion valve 5d is opened according to the suction superheat degree, the opening degree of the third electronic expansion valve 5c is 0, the liquid storage tank 7 is in a liquid storage mode, redundant refrigerant can enter the liquid storage tank for storage under the working condition, the normal operation of the unit is not affected, and the stability of the system is ensured.
This application utilizes the stock solution mode with unnecessary refrigerant to store under the condition that does not influence unit normal operating condition, supplements the refrigerant to the system under the not enough condition of unit ability. The operation refrigerant distribution and adjustment of the two modes ensure the operation reliability of the unit.
It will be appreciated by those skilled in the art that the invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The embodiments disclosed above are therefore to be considered in all respects as illustrative and not restrictive. All changes which come within the scope of or equivalence to the invention are intended to be embraced therein.
Claims (10)
1. The liquid return prevention air conditioning system is characterized by comprising a four-way valve (3), wherein a D port and an S port of the four-way valve (3) are respectively communicated with a high-pressure pipeline and a low-pressure pipeline of a compressor (1), a gas-liquid separator (8) is arranged on the low-pressure pipeline of the compressor (1), and an outdoor heat exchanger (4), a first electronic expansion valve (5 a), a second electronic expansion valve (5 b) and an indoor heat exchanger (6) are sequentially arranged between a C port and an E port of the four-way valve (3);
and a liquid storage tank (7) is further connected in parallel between the gas-liquid separator (8) and the indoor heat exchanger (6), one end of the liquid storage tank (7) close to the indoor heat exchanger (6) is provided with a third electronic expansion valve (5 c), and the other end of the liquid storage tank is provided with a fourth electronic expansion valve (5 d).
2. The anti-drainback air conditioning unit system as claimed in claim 1, wherein the liquid reservoir (7) is connected in parallel between the indoor heat exchanger (6) and an E port of the four-way valve (3).
3. Anti-drainback air conditioning unit system according to claim 1, characterized in that the reservoir tank (7) is connected in parallel between the S-port of the four-way valve (3) and the gas-liquid separator (8).
4. A control method of the liquid-return-preventing air conditioning system according to any one of claims 1 to 3, characterized by comprising:
judging the operation mode of the unit system;
and when the unit system is in a defrosting and minimum load refrigerating mode, the opening degree of the third electronic expansion valve (5 c) is controlled according to the suction superheat degree change delta Tss, and the fourth electronic expansion valve (5 d) is closed, so that the liquid storage tank (7) stores liquid.
5. The control method of a liquid-return preventing air conditioning unit system according to claim 4, wherein controlling the opening degree of the third electronic expansion valve (5 c) according to the suction superheat variation Δ Tss comprises:
when the delta Tss is less than or equal to minus 4 ℃, the third electronic expansion valve (5 c) is unloaded to the target opening degree at the speed of 8-10P/min;
when the temperature is lower than-4 ℃ and is less than delta Tss and less than 0 ℃, keeping the current opening degree of the third electronic expansion valve (5 c);
when the delta Tss is more than or equal to 0 ℃, loading the third electronic expansion valve (5 c) to a target opening degree at the speed of 10-20P/min;
wherein the change of the suction superheat degree delta Tss = Tss-Tss 1; tss is the intake superheat, and Tss1 is the target intake opening.
6. The control method of the liquid return prevention air conditioning system according to claim 4, wherein the judging of the operation mode of the unit system comprises:
acquiring an outdoor ring temperature Tho1 and an outer disc temperature Tho2 of a unit system;
when the outdoor environment temperature Tho1 is less than 12 ℃, the temperature Tho1-Tho2 is less than 8 ℃, and the unit system operates for more than 40min, the unit system enters a defrosting mode;
and when the outdoor environment temperature Tho1 is less than 23 ℃ and the unit system operates for more than 4 hours, the unit system enters a minimum load refrigeration mode.
7. The control method of the air conditioning system with liquid return prevention according to claim 4, wherein when the air conditioning unit is in the defrosting mode, the four-way valve (3) is controlled to be powered off, and the first electronic expansion valve (5 a) is fully opened and the second electronic expansion valve (5 b) is fully opened.
8. The control method of the liquid return prevention air conditioning system according to claim 4, wherein the second electronic expansion valve (5 b) is controlled to a minimum opening degree when the air conditioning unit is in a minimum load cooling mode.
9. The control method of the liquid return prevention air conditioning system according to claim 4, further comprising: and when the system is not in the defrosting and minimum load refrigeration mode, the opening degree of the fourth electronic expansion valve (5 d) is controlled according to the change of the suction superheat degree, and the third electronic expansion valve (5 c) is closed, so that liquid in the liquid storage tank (7) is separated.
10. The control method of the liquid-return preventing air conditioning system according to claim 9, wherein the controlling the opening degree of the fourth electronic expansion valve (5 d) according to the variation of the suction superheat degree comprises:
when the delta Tss is less than or equal to minus 4 ℃, the fourth electronic expansion valve (5 d) is unloaded to the target opening degree at the speed of 8-10P/min;
when the temperature is lower than-4 ℃ and is less than delta Tss and less than 0 ℃, keeping the current opening degree of the fourth electronic expansion valve (5 d);
when the delta Tss is more than or equal to 0 ℃, loading the fourth electronic expansion valve (5 d) to a target opening degree at the speed of 10-20P/min;
wherein, the change of the suction superheat degree delta Tss = Tss-Tss 1; tss is the intake superheat, and Tss1 is the target intake opening.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210991099.0A CN115371308B (en) | 2022-08-18 | 2022-08-18 | Liquid return prevention air conditioning system and control method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210991099.0A CN115371308B (en) | 2022-08-18 | 2022-08-18 | Liquid return prevention air conditioning system and control method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN115371308A true CN115371308A (en) | 2022-11-22 |
| CN115371308B CN115371308B (en) | 2023-12-19 |
Family
ID=84064988
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210991099.0A Active CN115371308B (en) | 2022-08-18 | 2022-08-18 | Liquid return prevention air conditioning system and control method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115371308B (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2024113911A1 (en) * | 2022-12-02 | 2024-06-06 | 珠海格力电器股份有限公司 | Air conditioning system, air conditioning unit and control method |
Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2001056159A (en) * | 1999-06-11 | 2001-02-27 | Daikin Ind Ltd | Air conditioner |
| WO2018094844A1 (en) * | 2016-11-25 | 2018-05-31 | 广州华凌制冷设备有限公司 | Air conditioning system and control method |
| CN109724203A (en) * | 2018-12-29 | 2019-05-07 | 青岛海尔空调器有限总公司 | Air conditioner and its control method |
| CN111609478A (en) * | 2020-04-23 | 2020-09-01 | 海信（山东）空调有限公司 | Air conditioner refrigerant automatic adjusting device, control method and air conditioning system |
| WO2020177284A1 (en) * | 2019-03-01 | 2020-09-10 | 青岛海尔空调电子有限公司 | Control method and control system for preventing liquid hammer in compressor of air conditioner |
| CN112413942A (en) * | 2020-11-24 | 2021-02-26 | 珠海格力电器股份有限公司 | Air conditioning system and control method thereof |
| CN112880228A (en) * | 2021-02-02 | 2021-06-01 | 三菱重工海尔(青岛)空调机有限公司 | Air conditioner liquid return prevention device and method for preventing air conditioner liquid return |
| WO2021184615A1 (en) * | 2020-03-16 | 2021-09-23 | 青岛海尔空调电子有限公司 | Control method for air conditioning system |
-
2022
- 2022-08-18 CN CN202210991099.0A patent/CN115371308B/en active Active
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2001056159A (en) * | 1999-06-11 | 2001-02-27 | Daikin Ind Ltd | Air conditioner |
| WO2018094844A1 (en) * | 2016-11-25 | 2018-05-31 | 广州华凌制冷设备有限公司 | Air conditioning system and control method |
| CN109724203A (en) * | 2018-12-29 | 2019-05-07 | 青岛海尔空调器有限总公司 | Air conditioner and its control method |
| WO2020177284A1 (en) * | 2019-03-01 | 2020-09-10 | 青岛海尔空调电子有限公司 | Control method and control system for preventing liquid hammer in compressor of air conditioner |
| WO2021184615A1 (en) * | 2020-03-16 | 2021-09-23 | 青岛海尔空调电子有限公司 | Control method for air conditioning system |
| CN111609478A (en) * | 2020-04-23 | 2020-09-01 | 海信（山东）空调有限公司 | Air conditioner refrigerant automatic adjusting device, control method and air conditioning system |
| CN112413942A (en) * | 2020-11-24 | 2021-02-26 | 珠海格力电器股份有限公司 | Air conditioning system and control method thereof |
| CN112880228A (en) * | 2021-02-02 | 2021-06-01 | 三菱重工海尔(青岛)空调机有限公司 | Air conditioner liquid return prevention device and method for preventing air conditioner liquid return |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2024113911A1 (en) * | 2022-12-02 | 2024-06-06 | 珠海格力电器股份有限公司 | Air conditioning system, air conditioning unit and control method |
Also Published As
| Publication number | Publication date |
|---|---|
| CN115371308B (en) | 2023-12-19 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US9151522B2 (en) | Air conditioner and control method thereof | |
| CN102042724B (en) | Refrigerant control component, air-conditioning refrigeration system and refrigerant circulation control method | |
| CN107631525B (en) | Two-stage compressor air conditioning system and control method and device thereof | |
| JP4767199B2 (en) | Air conditioning system operation control method and air conditioning system | |
| CN105371545A (en) | An air conditioner and a refrigerant circulation quantity adjusting method for a refrigeration system thereof | |
| JP7330367B2 (en) | Heat source unit, refrigeration cycle device and refrigerator | |
| CN112797587B (en) | Air conditioner control method and air conditioner system | |
| US11060771B2 (en) | Air conditioner with a refrigerant ratio adjustor | |
| CN109099610A (en) | Refrigeration system, air conditioner and the air-conditioner control method of Gas-supplying enthalpy-increasing | |
| JP4609469B2 (en) | Air conditioner | |
| CN114017898B (en) | Multi-split system | |
| CN111288676A (en) | chiller | |
| CN109612141B (en) | Refrigerating unit and control method and control device thereof | |
| CN115060015A (en) | Cooling system and control method | |
| CN115371308B (en) | Liquid return prevention air conditioning system and control method | |
| CN118031333B (en) | Air conditioning system, load control method, and computer-readable storage medium | |
| CN113513784A (en) | Multi-split refrigerant balance control method | |
| US11959676B2 (en) | Method for controlling a vapour compression system at a reduced suction pressure | |
| US6966193B2 (en) | Control of multi-circuit economized system | |
| CN117847813A (en) | Refrigerant circulation system, control method thereof and refrigeration equipment | |
| CN117469767A (en) | Air conditioning system, control method thereof and computer readable storage medium | |
| CN111219818B (en) | Air conditioning system, air conditioner and control method of air conditioner | |
| WO2022224304A1 (en) | Heat source unit | |
| JP7179445B2 (en) | refrigeration cycle equipment | |
| JP2002228284A (en) | Refrigeration equipment |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |